Description
Title of Invention: PROJECTOR
Technical Field
[0001] The present invention relates to a projector.
Background Art
[0002] In the related art, a projector is known which modulates a light beam emitted from a
light source to form an image based on image information, and projects the image on a
magnified scale onto a screen to be projected, such as a screen. As the light source, a
light source lamp, such as an ultrahigh pressure mercury lamp, is used which includes
a light-emitting tube having a discharge space, in which a pair of electrodes and a
light-emitting material, such as mercury, are sealed.
[0003] In this projector, for the purpose of reducing power consumption or reducing noise of
a fan which sends cooling air to the light source lamp, a low power mode may be used
in which power lower than rated power supplied in a normal power mode is supplied to
turn on the light source lamp. In this case, in the projector, the light source lamp and
the fan are driven on the basis of lamp electric power and the rotational speed of the
fan set in advance in accordance with each mode.
[0004] In the low power mode, since lamp electric power supplied to the light source lamp is
low, the period until the temperature of the light source lamp reaches the temperature
appropriate for turn-on in the low power mode is extended compared to the normal
power mode. For this reason, when the light source lamp will be started in the low
power mode, there is a problem in that it takes a lot of time to obtain desired
brightness.
[0005] On the other hand, a projector is known in which rated power is supplied to the light
source lamp until a set time elapses from the start of the light source lamp in the low
power mode, and the fan is driven at the rotational speed according to the low power
mode (for example, see PTL 1). In this projector, if the set time has elapsed, lamp
electric power according to the low power mode is supplied to the light source lamp.
Thus, at the time of the start in the low power mode, it is possible to reduce the time
when the temperature of the light source lamp reaches the appropriate temperature.
[0006] In this projector, when the light source lamp starts in the normal power mode, the fan
is driven at the rotational speed according to the normal power mode.
Citation List
Patent Literature
[0007] [PTL 1] JP-A-2003-295320
Summary of Invention
Technical Problem
[0008] When the temperature in the discharge space falls below a saturation threshold value
(the temperature at which mercury in the discharge space is substantially entirely in the
form of vapor), a halogen cycle in which tungsten evaporated from an electrode returns
to the electrode does not function appropriately, and the phenomenon that tungsten is
attached to the inner wall of the light-emitting tube, that is, blackening is likely to
occur. Blackening causes a decrease in luminance of the light source lamp and shortens
the lifetime of the light source lamp. In a state where the temperature in the discharge
space exceeds the saturation threshold value, and the halogen cycle functions appro
priately, accumulated blackening is likely to be eliminated.
[0009] On the other hand, in the projector described in PTL 1, when the turn-on of the light
source lamp starts, the temperature of the light source lamp temporarily increases. In
this case, however, the temperature in the discharge space may not increase to the tem
perature at which accumulated blackening can be eliminated, such that the effects of
eliminating blackening and suppressing the accumulation may not be obtained. If the
set time is set uniformly, unnecessary overheating of the light source lamp may occur,
and devitrification or blowing of the light source lamp may be stimulated.
[0010] For this reason, there is a need for a projector capable of suppressing the accu
mulation of blackening.
Solution to Problem
[001 1] An advantage of some aspects of the invention is to provide a projector capable of
suppressing the accumulation of blackening.
[0012] An aspect of the invention is directed to a projector including a light source lamp, a
lighting control unit adapted to supply a lamp electric power to turn on the light source
lamp, a cooling unit adapted to send a cooling fluid to cool the light source lamp, and a
start control unit adapted to, from the start of turn-on of the light source lamp until a
predetermined period elapses, adjust at least one of the length of the predetermined
period and a limited flow rate, which is the flow rate of the cooling fluid per unit time
sent from the cooling unit within the predetermined period, on the basis of an operation
history of the light source lamp to control the operation of the cooling unit.
[0013] According to the aspect of the invention, the start control unit adjusts at least one of
the length of the predetermined period when the cooling fluid at a flow rate according
to lamp electric power is sent from the start of turn-on of the light source lamp and the
limited flow rate, which is the flow rate of the cooling fluid per unit time to be set
within the predetermined period, on the basis of the operation history of the light
source lamp. That is, when the light source lamp is turned on under the condition that
blackening is likely to be generated and accumulated or when the light source lamp
will be turned on under the above-described condition, the limited flow rate is adjusted
to be smaller than the set flow rate or a limited period in which cooling air at a low
flow rate according to the limited flow rate is adjusted to be extended such that the
temperature of the light source lamp increases to the temperature at which blackening
is eliminated. Thus, it is possible to perform a process for eliminating blackening at the
time of turn-on of the light source lamp. Therefore, it is possible to suppress the accu
mulation of blackening in the light source lamp.
[0014] In the aspect of the invention, it is preferred that the projector further includes a
normal control unit adapted to control the cooling unit such that the cooling fluid at a
set flow rate set in advance in accordance with lamp electric power is sent to the light
source lamp after the predetermined period has elapsed.
[0015] According to this configuration, after the limited period set to such an extent that
blackening is eliminated has elapsed, the normal control unit performs control such
that the cooling unit sends the cooling fluid at the set flow rate according to lamp
electric power to the light source lamp, thereby suppressing an unnecessary increase in
temperature of the light source lamp. Therefore, it is possible to allow the light source
lamp to be stably turned on and to suppress the occurrence of devitrification or
blowing in the light source lamp.
[0016] In the aspect of the invention, it is preferred that the start control unit adjusts at least
one of the length of the predetermined period and the limited flow rate in accordance
with the operation history and lamp electric power supplied to the light source lamp.
[0017] There is an association between lamp electric power supplied to the light source lamp
and the state where blackening is likely to be generated and accumulated. For this
reason, in the aspect of the invention, at least one of the predetermined period and the
limited flow rate is adjusted in accordance with the operation history and lamp electric
power, thereby reliably suppressing the accumulation of blackening in the light source
lamp.
[0018] In the aspect of the invention, it is preferred that the operation history is the power
value of lamp electric power supplied to the light source lamp before the light source
lamp is turned off.
[0019] The power value of lamp electric power before turn-off is associated with the tem
perature of the light source lamp before turn-off. When the power value is high, the
temperature of the light source lamp is high, and when the power value is low, the tem
perature of the light source lamp is low. A state where the temperature of the light
source lamp is low refers to a state where blackening is likely to be generated and ac
cumulated.
[0020] For this reason, in the above configuration, the length of the predetermined period
and the limited flow rate are adjusted on the basis of the power value of lamp electric
power supplied to the light source lamp before turn-off. Thus, when the power value of
lamp electric power at the time of turn-off is low, it is possible to allow the tem
perature of the light source lamp to increase to the temperature at which blackening is
eliminated. Therefore, it is possible to shorten the time when the desired brightness is
reached and to more reliably suppress the accumulation of blackening.
[0021] Alternatively, in the aspect of the invention, it is preferred that the operation history
is the ratio of a rated power value of the light source lamp and an average power value
of lamp electric power supplied to the light source lamp before the light source lamp is
turned off.
[0022] The ratio of the average power value to the rated power value is associated with the
temperature of the light source lamp before turn-off. For example, when the ratio is
high, this indicates that lamp electric power close to rated power is supplied to the light
source lamp. In this case, the average temperature of the light source lamp is high, and
blackening is generated with difficulty. Meanwhile, when the ratio is low, this
indicates that lamp electric power lower than rated power is supplied. In this case, the
average temperature of the light source lamp is low, and blackening is easily
generated.
[0023] For this reason, in the above configuration, the length of the predetermined period
and the limited flow rate are adjusted on the basis of the ratio. Thus, similarly to the
above-described case based on the power value of lamp electric power, it is possible to
allow the temperature of the light source lamp to reliably increase to the temperature at
which blackening is eliminated. Therefore, it is possible to more reliably suppress the
accumulation of blackening.
[0024] Alternatively, in the aspect of the invention, it is preferred that the operation history
is the voltage value of lamp electric power supplied to the light source lamp before the
light source lamp is turned off.
[0025] The voltage value of lamp electric power before turn-off becomes the index of
measuring the generation state of blackening. For example, when the voltage value is
high, this indicates that the amount of evaporation of the electrode component
(tungsten) of the light source lamp does not increase. Meanwhile, when the voltage
value is low, this indicates that the temperature of the electrode tip increases and the
amount of evaporation of the electrode component increases, such that blackening is
likely to be generated.
[0026] For this reason, in the above configuration, the length of the predetermined period
and the limited flow rate are adjusted on the basis of the voltage value. Thus, similarly
to the above-described case, when the light source lamp is turned on in a state where
blackening is likely to be generated, it is possible to allow the temperature of the light
source lamp to reliably increase to the temperature at which blackening is eliminated at
the time of the start of next turn-on. Therefore, it is possible to more reliably suppress
the accumulation of blackening.
[0027] In the aspect of the invention, it is preferred that the light source lamp has a discharge
space in which a pair of electrodes and a discharge material are sealed, after insulation
breakdown in which insulation between a pair of electrodes is broken due to lamp
electric power supplied by the lighting control unit, the light source lamp is turned on
through a glow discharge period in which glow discharge is generated between a pair
of electrodes and an arc discharge period in which arc discharge is generated between a
pair of electrodes, and the start control unit adjusts at least one of the length of the pre
determined period and the limited flow rate in accordance with the length of the glow
discharge period.
[0028] If the glow discharge period is long, the period in which the electrode receives a
sputter by ions is extended. For this reason, the electrode component is likely to be
evaporated, and blackening is likely to be generated. The glow discharge period can be
determined by, for example, the time at which a lamp current after insulation
breakdown has reached to a predetermined current value, or the like.
[0029] For this reason, in the above configuration, the length of the predetermined period
and the limited flow rate are adjusted on the basis of the glow discharge period. Thus,
similarly to the above-described case, at the time of the start of turn-on of the light
source lamp in which the accumulation of blackening is expected, it is possible to
allow the temperature of the light source lamp to reliably increase to the temperature at
which accumulated blackening is eliminated. Therefore, it is possible to more reliably
suppress the accumulation of blackening.
[0030] In the aspect of the invention, it is preferred that the light source lamp has a discharge
space in which a pair of electrodes and a discharge material are sealed, and after in
sulation breakdown in which insulation between a pair of electrodes is broken due to
lamp electric power supplied by the lighting control unit, the light source lamp is
turned on through a glow discharge period in which glow discharge is generated
between a pair of electrodes and an arc discharge period in which arc discharge is
generated between a pair of electrodes. The cooling control unit may adjust at least one
of the length of the predetermined period and the limited flow rate in accordance with
lamp electric power if a cumulative turn-on time of the light source lamp is smaller
than a predetermined time, and may adjust at least one of the length of the prede
termined period and the limited flow rate in accordance with the length of the glow
discharge period if the cumulative turn-on time is equal to or greater than the prede
termined time.
[0031] Depending on the state of the light source lamp (for example, the deterioration state
of the electrode), it may be effective to set lamp electric power as an index when at
least one of the length of the predetermined period and the limited flow rate are
adjusted or it may be effective to set the length of the glow discharge period as the
index.
[0032] For example, if an arc length which is formed between the electrodes at the time of
normal turn-on is shortened, the current value increases, and blackening is likely to be
generated. Meanwhile, if the arc length is shortened and the current value increases, a
transition to arc discharge is easily made, and the glow discharge period is shortened.
In this case, the period in which the above-described sputter is generated is shortened,
and blackening is generated with difficulty. The importance of the factor for which
blackening is likely to be generated changes depending on the state of the light source
lamp.
[0033] In a comparatively first half period of the lifetime of the light source lamp, when the
arc length is shortened, there is a great influence on blackening being likely to be
generated compared to a case where the glow discharge period increases. In a com
paratively second half period, the relationship is reversed.
[0034] For this reason, in the above configuration, when the cumulative turn-on time of the
light source lamp is smaller than the predetermined time, at least one of the length of
the predetermined period and the limited flow rate is adjusted in accordance with lamp
electric power. When the cumulative turn-on time is equal to or greater than the prede
termined time, the adjustment is done in accordance with the length of the glow
discharge period. Thus, it is possible to perform effective cooling control of the light
source lamp according to the state of the light source lamp. Therefore, it is possible to
more reliably suppress the accumulation of blackening.
[0035] Alternatively, in the aspect of the invention, it is preferred that the light source lamp
has a discharge space in which a pair of electrodes and a discharge material are sealed,
and after insulation breakdown in which insulation between a pair of electrodes is
broken due to lamp electric power supplied by the lighting control unit, the light source
lamp is turned on through a glow discharge period in which glow discharge is
generated between a pair of electrodes and an arc discharge period in which arc
discharge is generated between a pair of electrodes. The cooling control unit may
adjust at least one of the length of the predetermined period and the limited flow rate in
accordance with lamp electric power if the voltage value of lamp electric power
supplied to the light source lamp before the light source lamp is turned off is lower
than a predetermined value, and may adjust at least one of the length of the prede
termined period and the limited flow rate in accordance with the length of the glow
discharge period if the voltage value is equal to or greater than the predetermined
value.
[0036] The lower the voltage value of lamp electric power and the longer the period in
which lamp electric power having the voltage value is supplied, the shorter the arc
length is. That is, when the voltage value is comparatively low, if the arc length is
extended, there is a great influence on the generation of blackening compared to a case
where the glow discharge period is extended. When the voltage value is comparatively
high, if the glow discharge period is extended, there is a great influence on the
generation of blackening compared to a case where the arc length is extended.
[0037] For this reason, in the above configuration, when the voltage value of lamp electric
power at the time of normal turn-on before turn-off is lower than the predetermined
value, at least one of the length of the predetermined period and the limited flow rate is
adjusted in accordance with lamp electric power. When the voltage value is equal to or
greater than the predetermined value, the adjustment is done in accordance with the
glow discharge period. In this case, it is possible to perform effective cooling control
of the light source lamp according to the state of the light source lamp. Therefore, it is
possible to more reliably suppress the accumulation of blackening.
[0038] Alternatively, in the aspect of the invention, it is preferred that the light source lamp
has a discharge space in which a pair of electrodes and a discharge material are sealed,
and after insulation breakdown in which insulation between a pair of electrodes is
broken due to lamp electric power supplied by the lighting control unit, the light source
lamp is turned on through a glow discharge period in which glow discharge is
generated between a pair of electrodes and an arc discharge period in which arc
discharge is generated between a pair of electrodes. The cooling control unit may
adjust at least one of the length of the predetermined period and the limited flow rate in
accordance with lamp electric power if the turn-on time of the light source lamp im
mediately before the light source lamp is turned off is equal to or greater than a prede
termined time, and may adjust at least one of the length of the predetermined period
and the limited flow rate in accordance with the length of the glow discharge period if
the turn-on time is smaller than the predetermined time.
[0039] In a state where the turn-on and turn-off of the light source lamp are frequently
repeated, the length of the glow discharge period has a great influence on the
generation of blackening.
[0040] For this reason, in the above configuration, when the turn-on time of the light source
lamp before turn-off (the previous turn-on time of the light source lamp) is equal to or
greater than the predetermined time, it is determined that the turn-on and turn-off of
the light source lamp are not frequently repeated, and at least one of the length of the
predetermined period and the limited flow rate is adjusted in accordance with lamp
electric power. Meanwhile, when the turn-on time is smaller than the predetermined
time, it is determined that the turn-on and turn-off of the light source lamp are
frequently repeated, and the adjustment is done in accordance with the glow discharge
period. In this case, it is possible to perform effective cooling control of the light
source lamp according to the state of the light source lamp. Therefore, it is possible to
more reliably suppress the accumulation of blackening.
[0041] In the aspect of the invention, it is preferred that the light source lamp has a discharge
space in which a pair of electrodes and a discharge material are sealed, and the start
control unit adjusts at least one of the length of the predetermined period and the
limited flow rate on the basis of, as the operation history, the voltage value of lamp
electric power supplied to the light source lamp after insulation breakdown in which
insulation is broken between a pair of electrodes.
[0042] When the light source lamp is restarted (in the case of hot restart), an increase in
power of the light source lamp is rapidly done. For this reason, since an increase in
temperature of the light source lamp is fast, it is necessary to adjust the sum of the flow
rate of cooling air sent to the light source lamp from the start of turn-on such that the
temperature of the light source lamp does not increase excessively.
[0043] Meanwhile, in the case of hot restart, since the internal pressure of the light source
lamp increases, insulation breakdown occurs with difficulty. For this factor, the flow
rate of the cooling fluid may increase on the basis of the voltage value of lamp electric
power for a while from when the restart starts.
[0044] The determination on hot restart or not can be done on the basis of the voltage value
of lamp electric power after insulation breakdown.
[0045] For this reason, in the above configuration, when it is determined to be hot restart on
the basis of the voltage value of lamp electric power after insulation breakdown, the
length of the predetermined period and the limited flow rate are adjusted, thereby sup
pressing an excessive increase in temperature of the light source lamp. Therefore, it is
possible to stabilize the turn-on of the light source lamp, to suppress the occurrence of
devitrification and blowing, and to achieve the long lifetime of the light source lamp.
[0046] In the aspect of the invention, it is preferred that the projector further includes a
storage unit for storing the operation history of the light source lamp in association
with driving information of the cooling unit according to the length of the prede
termined period and the limited flow rate. The start control unit may acquire the length
of the predetermined period and the driving information according to the operation
history of the light source lamp from the storage unit, and may put the cooling unit into
operation.
[0047] According to the above configuration, the length of the predetermined period and the
driving information of the cooling unit stored in the storage unit are acquired on the
basis of the operation history of the light source lamp. Thus, in order to put the cooling
unit into operation, a process for calculating the length of the predetermined period and
the limited flow rate by an arithmetic operation can be omitted. Therefore, it is possible
to simplify the process of the start control unit and to appropriately put the cooling unit
into operation.
[0048] In the aspect of the invention, it is preferred that the cooling unit includes a fan
which sends the cooling fluid, and the driving information is a fan voltage value which
is supplied to the fan.
[0049] According to the above configuration, the fan voltage value is stored in the storage
unit as the driving information along with the length of the predetermined period.
Thus, the start control unit can control the operation of the fan using information
acquired from the storage unit. Therefore, it is possible to further simplify the process
of the start control unit.
Brief Description of Drawings
[0050] [fig. l]Fig. 1 is a block diagram showing the configuration of a projector according to a
first embodiment of the invention.
[fig.2]Fig. 2 is a sectional view showing a light source device in the above-described
embodiment.
[fig.3]Fig. 3 is a diagram showing an example of a start parameter table in the abovedescribed
embodiment.
[fig.4]Fig. 4 is a flowchart showing a cooling control process in the above-described
embodiment.
[fig.5]Fig. 5 is a diagram showing power transition when a cooling control process is
performed in the above-described embodiment.
[fig.6]Fig. 6 is a diagram showing an example of a start parameter table according to a
second embodiment of the invention.
[fig.7]Fig. 7 is a diagram showing an example of a start parameter table according to a
third embodiment of the invention.
[fig.8]Fig. 8 is a block diagram showing the configuration of a projector according to a
fourth embodiment of the invention.
[fig.9]Fig. 9 is a diagram showing an example of a start parameter table in the abovedescribed
embodiment.
[fig.l0]Fig. 10 is a flowchart showing a cooling control process in the above-described
embodiment.
[fig. 1l]Fig. 11 is a block diagram showing the configuration of a projector according
to a fifth embodiment of the invention.
[fig. 12] Fig. 12 is a diagram showing an example of a restart parameter table according
to an eighth embodiment of the invention.
[fig.l3]Fig. 13 is a diagram showing the relationship between transition of a power
value at the time of the restart of a light source lamp and transition of a fan voltage
value according to a ninth embodiment of the invention.
Description of Embodiments
[005 1] First Embodiment
Hereinafter, a first embodiment of the invention will be described with reference to
the drawings.
Fig. 1 is a block diagram showing the configuration of a projector 1 of this em
bodiment.
[0052] The projector 1 of this embodiment modulates a light beam emitted from a light
source in accordance with image information, and projects the image on a projection
screen, such as a screen, on a magnified scale. Though the details will be described
below, in order to eliminate blackening accumulated in a light source lamp serving as a
light source, the projector 1 temporarily increases the temperature of the light source
lamp (specifically, the temperature in the discharge space) to a temperature higher than
an optimum temperature on the basis of the operation state of the light source lamp at
the time of the start of turn-on.
[0053] Specifically, in the projector 1, a limited period in which the flow rate of a cooling
fluid (cooling air) sent to the light source lamp falls below a set flow rate according to
lamp electric power is provided on the basis of the operation history of the light source
lamp, thereby limiting cooling of the light source lamp to increase the temperature in
the discharge space. The limited period corresponds to a predetermined period
according to the invention.
[0054] As shown in Fig. 1, the projector 1 includes an operating device 2, a power supply
device 3, an image forming apparatus 4, a detection device 5, a cooling device 6, and a
control device 7.
[0055] The operating device 2 is constituted by an operating panel provided in the top
surface or the like of the projector 1. The operating panel is provided with a plurality
of keys. The operating panel outputs an operating signal according to an input key to
the control device 7. The keys include a power key which is used to power on/off the
projector 1, a switch key which is used to switch the operation mode of the light source
lamp for reduction in power consumption or the like, a mute key which is used to
display a mute image instead of display of an image according to image information
input from the outside, and the like.
[0056] The power supply device 3 supplies power to each electronic part constituting the
projector 1. Specifically, the power supply device 3 supplies power to the control
device 7 and also supplies power to each electronic part (for example, a light source
lamp 411 described below) under the control of the control device 7.
[0057] Though not shown, the power supply device 3 includes a down-converter, an inverter
circuit, and an igniter circuit so as to turn on the light source lamp 411 (see Fig. 2).
[0058] The down-converter removes high-frequency noise, and also deboosts and rectifies a
supplied direct current.
[0059] The inverter circuit converts a direct current to a square-wave alternating current.
[0060] The igniter circuit applies a high-voltage pulse to electrodes E of the light source
lamp 4 11 to perform insulation breakdown between the electrodes E, and requests to
start the light source lamp 411.
[0061] Fig. 2 is a sectional view showing a light source device 41.
[0062] The image forming apparatus 4 modulates a light beam in accordance with a driving
signal input from the control device 7, and projects the image on the projection screen
on a magnified scale. The image forming apparatus 4 includes a light source device 41,
a light modulation device 42, and a projection optical device 43.
[0063] As shown in Fig. 2, the light source device 4 1 includes a light source lamp 411, and a
main reflecting mirror 412 and a sub reflecting mirror 413 which are attached to the
light source lamp 411.
[0064] Of these, the light source lamp 411 includes a light-emitting portion 4111 which has
a discharge space S, in which a pair of electrodes E (El, E2) and a light-emitting
material are sealed, sealing portions 4112 and 4113 which extend in opposing d i
rections from the light-emitting portion 4111, and lead wires 4114 and 4115 which
have one end connected to the electrodes E and another end extending outside the light
source lamp 411.
[0065] Though the details will be described below, the light source lamp 4 11 is turned on
with luminance according to lamp electric power supplied from the power supply
device 3.
[0066] Returning to Fig. 1, the light modulation device 42 modulates a light beam emitted
from the light source lamp 4 11 to modulate the light beam in accordance with the
driving signal. For the light modulation device 42, a transmissive or reflective liquid
crystal panel may be used, or a device using micro-mirrors or the like may be used.
[0067] The projection optical device 43 projects the modulated light beam on a magnified
scale, and is constituted by a combination lens including a lens barrel and a plurality of
lenses accommodated in the lens barrel.
[0068] The detection device 5 is connected to the power supply device 3, and detects the
voltage value and current value of lamp electric power supplied by the power supply
device 3. The detection device 5 outputs the detected voltage value and current value
to the control device 7.
[0069] The cooling device 6 sends cooling air introduced from the outside of the projector 1
to various heat-generating parts constituting the projector 1, and cools the heatgenerating
parts. For example, the cooling device 6 sends cooling air to the light source
lamp 4 11 to cool the light source lamp 411. The cooling device 6 has a fan 6 1 which
ejects cooling air, and the fan 6 1 is driven at a rotational speed (the number of rotations
per unit time) according to the voltage value of a fan voltage supplied from the control
device 7.
[0070] Configuration of Control Device
The control device 7 is constituted by a circuit board on which a CPU (Central
Processing Unit), a RAM (Random Access Memory), a flash memory, and the like are
mounted, and controls the operation of the projector 1 in accordance with the operating
signal input from the operating device 2 or autonomously.
[0071] The control device 7 has a storage unit 7 1 constituted by a flash memory, and a main
control unit 72, an image processing unit 73, a lighting control unit 74, a timing unit
75, and a cooling control unit 76 which are realized when the CPU processes programs
and data stored in the storage unit 71.
[0072] Configuration of Storage Unit
The storage unit 71 stores various programs and data necessary for the operation of
the projector 1. For example, the storage unit 7 1 stores a driving parameter table for
driving the cooling device 6 as data. In the driving parameter table, driving parameters
set in advance are set on the basis of the flow rate (a set flow rate according to the
lamp electric power value) of cooling air to be sent to the light source lamp 411 for
each operation mode of the light source lamp 411. When the driving of the fan 6 1 is
controlled by an application voltage level, the driving parameters are stored as fan
voltage values according to the operation modes. When the driving of the fan is
controlled by PWM (Pulse Width Modulation), the driving parameters are stored as
duty ratios for the respective operation modes.
[0073] In the following description, description will be provided as a case where the driving
of the fan 6 1 is controlled by the application voltage level.
[0074] The storage unit 7 1 stores the operation history of the light source lamp 4 11. In this
embodiment, the storage unit 71 stores the lamp electric power value at the time of
power-off of the projector 1, that is, at the time of turn-off of the light source lamp 411
under the control of the main control unit 72 described below.
[0075] The storage unit 7 1 stores a start parameter table in which for each operation mode at
the time of the start of turn-on of the light source lamp 411, the operation history (a
power value at the time of previous turn-off) of the light source lamp 4 11 is associated
with the limited period and driving information (the fan voltage value of the fan 61) of
the cooling device 6 to be applied within the limited period.
[0076] The limited period is the period from the start of turn-on of the light source lamp 411
until the cooling fluid at the set flow rate according to the lamp electric power value
supplied to the light source lamp 4 11 is sent. In other words, the limited period is the
period from the start of turn-on of the light source lamp 411 until the cooling device 6
is operated by the driving parameters according to the lamp electric power value
supplied to the light source lamp 411, and the period in which the start parameters are
applied.
[0077] Fig. 3 is a diagram showing an example of a start parameter table. Fig. 3 shows a
start parameter table which is applied when the turn-on of the light source lamp 4 11 is
started in a high power mode.
[0078] As shown in Fig. 3, in the start parameter table, a start parameter of a pattern A and a
start parameter of a pattern B are set.
[0079] In the start parameter of the pattern A, a constant fan voltage value is set, and a
different limited period for each power value at the time of previous turn-off is set. In
the pattern A, the higher the power value at the time of previous turn-off, the shorter
the limited period is set. To the contrary, the lower the power value at the time of
previous turn-off, the longer the limited period is set.
[0080] In the start parameter of the pattern B, a constant limited period is set, and a different
fan voltage value for each power value at the time of previous turn-off is set. In the
pattern B, the higher the power value at the time of previous turn-off, the higher the fan
voltage value is set. The lower the power value at the time of previous turn-off, the
lower the fan voltage value is set.
[008 1] The limited period is set to be longer than the period when the light source lamp 411
reaches a turn-on state with target power after insulation breakdown. The fan voltage
values are set to be equal to or smaller than a fan voltage value for sending cooling air
at the set flow rate according to the lamp electric power value supplied to the light
source lamp 411. That is, the fan voltage value is lower than the fan voltage values of
the driving parameters.
[0082] In the start parameter table, at the time of the start in the high power mode, a limited
period is set to be shorter with a constant fan voltage value in the pattern A, and a fan
voltage value is set to be higher with a constant time limit in the pattern B. This is to
prevent the temperature of the light source lamp 411 from increasing unnecessarily
while an increase in temperature of the light source lamp 411 and elimination of ac
cumulated blackening are rapidly done by lamp electric power being supplied.
[0083] In the table, at the time of the start in a low power mode, a limited period is set to be
longer with a constant fan voltage value in the pattern A, and a fan voltage value is set
to be lower with a constant limited period in the pattern B. This is to extend the period
for eliminating accumulated blackening because an increase in temperature of the light
source lamp 4 11 by lamp electric power being supplied is not rapidly done.
[0084] Configuration of Main Control Unit
The main control unit 72 controls the operation of the control device 7 and consequently
controls the overall operation of the projector 1.
[0085] For example, the main control unit 72 sets the operation mode of the light source
lamp 4 11 on the basis of the performance state of the mute function and the input of
the switch key, and outputs a control signal to the lighting control unit 74 such that
lamp electric power having a power value according to the operation mode is supplied
to the light source lamp 411. The operation modes include a high power mode in which
the light source lamp 4 11 is turned on with rated power, an intermediate power mode
in which the light source lamp 4 11 is turned on with lamp electric power having a
power value lower than rated power, a low power mode when the mute function
(display of a mute image) is performed, and the like. In this embodiment, target power
is set to 230 W, 160 W, and 70 W respectively in the operation modes of high power,
intermediate power, and low power, and lamp electric power having these power
values are supplied to the light source lamp 411. Target power in each operation mode
may be appropriately set in accordance with the type of the light source lamp 4 11, a
power supply function of the power supply device 3, or the like.
[0086] When the power key is input and the projector 1 is powered off, the main control unit
72 stores the lamp electric power value supplied to the light source lamp 4 11 in the
storage unit 71.
[0087] Configuration of Image Processing Unit
The image processing unit 73 converts image information (including an image signal
and image data), which is received from an external apparatus, such as a PC to image
information corresponding to the image forming apparatus 4 under the control of the
main control unit 72. At this time, the image processing unit 73 performs a prede
termined correction process on the image information. The image processing unit 73
outputs a driving signal based on the image information subjected to the correction
process to the image forming apparatus 4.
[0088] Configuration of Lighting Control Unit and Timing Unit
The lighting control unit 74 performs control such that the operation of the power
supply device 3 supplies lamp electric power in an operation mode based on a control
signal from the main control unit 72 to the light source lamp 4 11 to turn on the light
source lamp 411.
[0089] The timing unit 75 measures the elapsed time from the start of turn-on of the light
source lamp 411 under the control of the main control unit 72.
[0090] Configuration of Cooling Control Unit
The cooling control unit 76 performs control such that the cooling device 6 sends
cooling air for cooling the constituent parts of the projector 1. In particular, the cooling
control unit 76 performs control on the basis of the control signal input from the main
control unit 72 such that the cooling device 6 sends cooling air for cooling the light
source lamp 4 11. At this time, the cooling control unit 76 provides the limited period at
the time of the start of turn-on of the light source lamp 411, such that an increase in
temperature of the light source lamp 4 11 is rapidly done, thereby shortening the time
when the desired brightness is reached and eliminating blackening generated in the
discharge space S of the light source lamp 411.
[0091] In order to realize this function, the cooling control unit 76 has a mode acquisition
unit 761, an operation history acquisition unit 762, a start control unit 763, an elapsed
time determination unit 764, and a normal control unit 765.
[0092] The mode acquisition unit 761 acquires the operation mode at the time of the start of
turn-on of the light source lamp 411 indicated by a control signal input from the main
control unit 72 (the same as the control signal input to the lighting control unit 74).
[0093] The operation history acquisition unit 762 acquires the operation history (in this em
bodiment, the lamp electric power value at the time of previous turn-off) of the light
source lamp 411 stored in the storage unit 7 1 by the main control unit 72 when the
projector 1 is powered off.
[0094] The start control unit 763 corresponds to start control unit according to the invention,
adjusts the length of the limited period on the basis of the operation state of the light
source lamp 411, and controls the fan voltage value to be applied to the fan 6 1 to adjust
the limited flow rate, which is the flow rate of a cooling fluid per unit time sent from
the cooling device 6 within the limited period, thereby operating the cooling device 6.
[0095] Specifically, the start control unit 763 acquires the operation mode at the time of the
start of turn-on acquired by the mode acquisition unit 761 and the start parameters
according to the operation history acquired by the operation history acquisition unit
762 from the storage unit 71. At this time, when the operation mode is frequently
switched, with regard to the start parameters acquired by the start control unit 763, the
start parameters of the pattern A are acquired. When the operation mode is not
frequently switched, the start parameters of the pattern B are acquired. Of the patterns
A and B, the start parameters to be acquired may be set in advance.
[0096] Until the time limit set in the acquired start parameters elapses from the start of turnon
of the light source lamp 411, the start control unit 763 performs control such that
the power supply device 3 applies the voltage of the fan voltage value set in the same
manner to the fan 61. Thus, the flow rate of cooling air sent to the light source lamp
4 11 is suppressed to be smaller than the set flow rate according to the lamp electric
power value, and the temperature of the light source lamp 411 increases to the tem
perature at which accumulated blackening can be eliminated.
[0097] The elapsed time determination unit 764 acquires the time measured by the timing
unit 75 from the start of turn-on of the light source lamp 411, and determines whether
or not the set time limit has elapsed.
[0098] The normal control unit 765 performs control such that, after the limited period has
elapsed, the cooling device 6 (fan 61) sends cooling air at the set flow rate according to
the lamp electric power value to the light source lamp 411.
[0099] Specifically, the normal control unit 765 acquires the driving parameters according to
the operation mode acquired by the mode acquisition unit 761 from the storage unit 71.
After the limited period has elapsed, the normal control unit 765 puts the cooling
device 6 (fan 61) into operation on the basis of the acquired driving parameters. Thus,
cooling air at a flow rate adjusted to the power value of lamp electric power being
supplied is sent to the light source lamp 411, and the light source lamp 4 11 is cooled to
an optimum temperature.
[0100] Cooling Control Process When Turn-On of Light Source Lamp Starts
Fig. 4 is a flowchart showing a cooling control process which is performed by the
control device 7 when the turn-on of the light source lamp 411 starts.
[0101] If the power key is input and power is on, the control device 7 performs control such
that the light source lamp 4 11 is turned on by the lighting control unit 74 in the
operation mode set by the user, and also performs the following cooling control
process. This cooling control process is performed when the CPU constituting the
control device 7 executes a program stored in the storage unit 71.
[0102] As shown in Fig. 4, in the cooling control process, first, the mode acquisition unit
761 acquires the operation mode of the light source lamp 4 11 on the basis of the
control signal input from the main control unit 72 (Step SI).
[0103] Next, the operation history acquisition unit 762 acquires the power value at the time
of previous turn-off which is the operation history stored in the storage unit 7 1 (Step
S2).
[0104] The start control unit 763 acquires the start parameters according to the acquired
power value at the time of previous turn-off with reference to the start parameter table
according to the acquired operation mode from the start parameter tables (Step S3).
[0105] The start control unit 763 performs control such that the power supply device 3
supplies a voltage according to the fan voltage value included in the start parameters to
the fan 6 1 until the time limit included in the acquired start parameters elapses from
when lamp electric power starts to be supplied to the light source lamp 411 (Step S4).
[0106] The elapsed time determination unit 764 determines whether or not the measured
time of the timing unit 75 which starts to be measured along with the start of the
supply of lamp electric power to the light source lamp 411 has elapsed the time limit
(Step S5).
[0107] When the elapsed time determination unit 764 determines that the measured time has
not elapsed the time limit, the control device 7 repeatedly performs Step S5, and suc
cessively performs Step S4. Thus, the temperature of the light source lamp 411
increases to the temperature at which blackening is eliminated.
[0108] When the elapsed time determination unit 764 determines that the measured time has
elapsed the time limit, the normal control unit 765 acquires the driving parameters
according to the operation mode acquired in Step S1 from the storage unit 71 (Step
S6).
[0109] The normal control unit 765 puts the cooling device 6 into operation in accordance
with the acquired driving parameters (Step S7). Thus, the light source lamp 4 11 is
cooled at a temperature adjusted to the set operation mode (lamp electric power value).
[0110] Fig. 5 is a diagram showing power transition when the cooling control process is
performed and power transition when the cooling control process is not performed at
the time of the start of turn-on of the light source lamp 411.
[0111] The power transition of the light source lamp 411 when the cooling control process is
not performed is indicated by a fine dotted line in Fig. 5. In this case, as indicated by a
bold dotted line in Fig. 5, the fan 6 1 is driven with the driving parameter (the fan
voltage value of 8.3 V or 10.9 V) set in accordance with the operation mode from the
start of turn-on of the light source lamp 411, and cooling air at a set flow rate
according to the operation mode is sent to the light source lamp 4 11 by the cooling
device 6.
[0112] The set flow rate is the flow rate of cooling air for maintaining the temperature of the
light source lamp 411, which is stably turned on in the operation mode, to the optimum
temperature. For this reason, if cooling air at the set flow rate is sent at the time of the
start of turn-on of the light source lamp 4 11, an increase in temperature of the light
source lamp 411 in a low-temperature state (for example, room temperature) is not
rapidly done. For this reason, the time when target power is reached is extended, and
the time when the desired brightness is reached is extended. If cooling air at the set
flow rate is sent to the light source lamp 4 11, it is hard to allow the temperature of the
light source lamp 4 11 to increases to the temperature at which blackening can be
eliminated. For this reason, blackening accumulated by the turn-on of the light source
lamp 4 11 in the low power mode is hardly eliminated.
[0113] The power transition of the light source lamp 411 when the cooling control process is
performed is indicated by a fine solid line in Fig. 5. In this case, as indicated by a bold
sold line in Fig. 5, the fan 6 1 is operated by the start parameter (in the example of Fig.
5, a fan voltage value of 4 V) acquired on the basis of the operation history of the light
source lamp 411 until a limited period A elapses from the start of turn-on of the light
source lamp 411. For this reason, cooling air at a flow rate smaller than the set flow
rate according to the operation mode is set to the light source lamp 4 11 by the cooling
device 6.
[0114] For this reason, in the limited period A, the temperature of the light source lamp 411
rapidly increases, and the time when target power is reached is shortened compared to
the above-described case, such that the time when the desired brightness is reached is
shortened. The limited period A is set to be longer than the period until target power is
reached from insulation breakdown of light source lamp 411, such that the temperature
of the light source lamp 411 easily reaches the temperature at which blackening can be
eliminated. Thus, blackening accumulated in the light source lamp 4 11 is eliminated.
[0115] According to the projector 1 of this embodiment described above, the following
effects are obtained.
[0116] The start control unit 763 adjusts the length of the limited period and the fan voltage
value corresponding to the limited flow rate on the basis of the operation state of the
light source lamp 411. Thus, when the light source lamp 4 11 is turned on under the
condition that blackening is likely to be generated and accumulated or when the light
source lamp 411 will be turned on under the above-described condition, it is possible
to allow the temperature of the light source lamp 4 11 to increase to the temperature at
which blackening is eliminated. Therefore, it is possible to perform a process for
eliminating blackening at each time of turn-on of the light source lamp 411, thereby
suppressing the accumulation of blackening.
[01 17] After the limited period has elapsed, the normal control unit 765 performs control
such that the cooling device 6 sends cooling air at the set flow rate according to lamp
electric power to the light source lamp 411. Thus, it is possible to suppress an increase
in temperature of the light source lamp 411. Therefore, it is possible to allow the light
source lamp 411 to be stably turned on and to suppress the occurrence of devitri
fication or blowing in the light source lamp 411.
[0118] The start control unit 763 adjusts at least one of the length of the limited period and
the limited flow rate on the basis of the operation history of the light source lamp 411.
Specifically, the start control unit 763 adjusts the length of the limited period and the
fan voltage value on the basis of the power value of lamp electric power before turnoff.
Thus, when the power value of lamp electric power at the time of turn-off is low,
and the accumulation of blackening is expected, at the time of next turn-on of the light
source lamp 4 11, it is possible to allow the temperature of the light source lamp 4 11 to
reliably increase to the temperature at which blackening is eliminated. Therefore, it is
possible to shorten the time when the desired brightness is reached and to more reliably
suppress the accumulation of blackening.
[01 19] The start control unit 763 acquires the start parameters, in which the length of the
limited period and the driving information are set, from the storage unit 71 on the basis
of the operation state of the light source lamp 411. Thus, in order to put the fan 6 1 into
operation, the process for calculating the length of the limited period and the limited
flow rate can be omitted by an arithmetic operation. Therefore, it is possible to
simplify the process of the start control unit 763, and to appropriately put the cooling
device 6 into operation.
[0120] The storage unit 7 1 stores the voltage value of the fan voltage as the driving in
formation. Thus, the start control unit 763 can control the operation of the fan 6 1 using
the voltage value acquired from the storage unit 71. Therefore, it is possible to further
simplify the process of the start control unit 763.
[0121] Second Embodiment
Hereinafter, a second embodiment of the invention will be described.
[0122] A projector of this embodiment has the same configuration as the above-described
projector 1. In the projector 1, the power value at the time of previous turn-off is held
as the operation history of the light source lamp 4 11. In contrast, in the projector of this
embodiment, the ratio (average-rated power ratio) of an average power value in a pre
determined period before previous turn-off and a rated power value is held as the
operation history, and the start parameters are acquired on the basis of the ratio. From
this point, the projector of this embodiment is different from the projector 1. In the
following description, the same or substantially same parts as the parts described above
are represented by the same reference numerals, and description thereof will not be
repeated.
[0123] The projector of this embodiment includes the same configuration and function as the
projector 1, except that the operation of the main control unit 72, the stored content of
the storage unit 71, and the content of the cooling control process are partially
different.
[0124] Specifically, the main control unit 72 calculates the average -rated power ratio as the
operation history of the light source lamp 411, and stores the average-rated power ratio
in the storage unit 7 1 when the projector is powered off. The average-rated power ratio
is the percentage of the average lamp electric power value with respect to the rated
power value (in this embodiment, 230 W) of the light source lamp 4 11. In this em
bodiment, the average lamp electric power value in a predetermined period before
turn-off is used as the average lamp electric power value, thereby achieving reduction
in the capacity of the storage unit 71. However, if there is a sufficient margin in the
capacity, an average lamp electric power value from the start of turn-on of the light
source lamp 411 until turn-off may be used.
[0125] Instead of the above-described start parameter table, the storage unit 7 1 stores a start
parameter table, in which the average-rated power ratio at the time of previous turn-on
serving as the operation history of the light source lamp 4 11 is set in association with
the driving information (fan voltage value) and the limited period, for each operation
mode at the time of the start of turn-on of the light source lamp 411.
[0126] Fig. 6 is a diagram showing an example of a start parameter table stored in the
storage unit 7 1 of the projector of this embodiment. Fig. 6 shows a start parameter
table which is applied when the turn-on of the light source lamp 411 starts in the high
power mode.
[0127] For example, as shown in Fig. 6, in a start parameter table which is applied when the
operation mode at the time of the start of turn-on is the high power mode, the start p a
rameters of the patterns A and B described above are set for each average-rated power
ratio.
[0128] Of these, in the start parameters of the pattern A, a constant fan voltage value is set,
and a different limited period is set for each average-rated power ratio. In the pattern
A, the higher the average-rated power ratio, the shorter the limited period is set.
[0129] In the start parameters of the pattern B, a constant limited period is set, and a
different fan voltage value is set for each average-rated power ratio. In the pattern B,
the higher the average-rated power ratio, the higher the fan voltage value is set.
[0130] As described above, the limited period is set to be longer than the period when the
light source lamp 411 reaches the turn-on state with target power from insulation
breakdown, and each fan voltage value is set to be equal to or smaller than the fan
voltage value for sending cooling air at the set flow rate according to the lamp electric
power value.
[0131] In the projector of this embodiment, when the light source lamp 411 starts to be
turned on, the control device 7 reads a program stored in the storage unit 71, and
performs the same cooling control process as the above-described cooling control
process.
[0132] In Step SI of the cooling control process, the mode acquisition unit 761 acquires the
operation mode at the time of the start of turn-on of the light source lamp 4 11 on the
basis of an input control signal.
[0133] In Step S2, the operation history acquisition unit 762 acquires the average-rated
power ratio stored in the storage unit 71 at the time of previous turn-off of the light
source lamp 411.
[0134] In Step S3, the start control unit 763 acquires the start parameters according to the
operation mode and the average-rated power ratio acquired in Steps S1 and S2.
[0135] Thereafter, in Step S4, the start control unit 763 controls the operation of the cooling
device 6 (fan 61) on the basis of the limited period and the fan voltage value of the
acquired start parameters.
[0136] Steps S5 to S7 are the same as the above-described processing contents.
[0137] According to the projector of this embodiment described above, in addition to the
same effects as the above-described projector 1, the following effects are obtained.
[0138] When the average-rated power ratio before turn-off is high, this indicates that lamp
electric power close to rated power is supplied to the light source lamp. In this case, it
can be determined that the average temperature of the light source lamp is high, and
blackening is generated with difficulty. Meanwhile, when the average-rated power
ratio is low, this indicates that lamp electric power lower than rated power is supplied.
In this case, it can be determined that the average temperature of the light source lamp
is low, and blackening is likely to be generated.
[0139] For this reason, the start control unit 763 adjusts the length of the limited period and
the limited flow rate on the basis of the average-rated power ratio before turn-off, such
that the fan voltage having a voltage value according to the limited flow rate is
supplied to the fan 6 1 until the limited period elapses from the start of turn-on of the
light source lamp 411. Thus, when the light source lamp 4 11 is turned on under the
condition that blackening is likely to be generated, at the time of the next start, it is
possible to allow the temperature of the light source lamp 4 11 to reliably increase to
the temperature at which blackening is eliminated. Therefore, it is possible to more
reliably suppress the accumulation of blackening.
[0 140] Third Embodiment
Next, a third embodiment of the invention will be described.
[0141] A projector of this embodiment has the same configuration as the above-described
projector 1. In the projector 1, the lamp electric power value at the time of previous
turn-off is stored as the operation history of the light source lamp 4 11. In contrast, in
the projector of this embodiment, the lamp voltage and the operation mode of the light
source lamp 411 before turn-off are stored as the operation history. From this point, the
projector of this embodiment is different from the projector 1. In the following de
scription, the same or substantially same parts as the parts described above are rep
resented by the same reference numerals, and description thereof will not be repeated.
[0142] The projector of this embodiment includes the same configuration as the projector 1,
except that the operation of the main control unit 72, the stored content of the storage
unit 71, and the operation of the cooling control unit 76 in the cooling control process
are partially different.
[0143] Of these, when the projector is powered off, the main control unit 72 stores the lamp
voltage value detected by the detection device 5 and the operation mode of the light
source lamp 4 11 in the storage unit 7 1 as the operation history of the light source lamp
411. Although in this embodiment, the lamp voltage value at the time of turn-off is
stored, the invention is not limited thereto. An average lamp voltage value of a prede
termined period when the projector is powered off may be stored.
[0144] The storage unit 7 1 stores start parameter tables which are different from the abovedescribed
start parameter tables. The start parameter tables are provided for each
operation mode at the time of the start of turn-on of the light source lamp 411, and
divided for each operation mode at the time of previous turn-off of the light source
lamp 4 11. In each start parameter table, the lamp voltage value at the time of previous
turn-off as the operation history of the light source lamp 4 11 is set in association with
the driving information (fan voltage value) and the limited period.
[0145] Fig. 7 is a diagram showing an example of a start parameter table stored in the
storage unit 71. Fig. 7 shows a start parameter table which is applied when the
operation mode of the light source lamp 4 11 at the time of previous turn-off and the
operation mode of the light source lamp 4 11 at the time of the start of turn-on are the
high power mode.
[0146] For example, in the start parameter table which is applied when the operation modes
of the light source lamp 4 11 at the time of previous turn-off and at the time of the start
of turn-on are the high power mode, as shown in Fig. 7, the start parameters of the
patterns A and B are set for each lamp voltage value.
[0147] Of these, in the start parameters of the pattern A, a constant fan voltage value is set,
and a different limited period for each lamp voltage value at the time of the start of
turn-on is set. In the pattern A, the higher the lamp voltage value, the shorter the
limited period is set.
[0148] In the start parameters of the pattern B, a constant limited period is set, and a
different fan voltage value for each lamp voltage value at the time of the start of turnon
is set. In the pattern B, the higher the lamp voltage value, the higher the fan voltage
value is set.
[0149] As described above, the limited period is set to be longer than the period when the
light source lamp 411 reaches the turn-on state with target power after insulation
breakdown, and each fan voltage value is set to be equal to or smaller than the fan
voltage value for sending cooling air at the set flow rate according to the lamp electric
power value.
[0150] A change in the lamp voltage when lamp electric power having a certain power value
is supplied can become the index of the arc length which is formed between the
electrodes of the light source lamp 411. Specifically, when the lamp voltage value is
high, this indicates that the arc length is long. In this case, blackening is generated with
difficulty. Meanwhile, when the lamp voltage value is low, this indicates that the arc
length is short. In this case, blackening is likely to be generated.
[0151] As described above, when the lamp voltage value is low, it is determined that
blackening is accumulated. For this reason, a long limited period or a low fan voltage
value is set in the start parameters, such that cooling air at a flow rate smaller than the
set flow rate according to the lamp electric power value is sent to the light source lamp
411. Thus, cooling of the light source lamp 4 11 is temporarily limited, and an increase
in temperature of the light source lamp 4 11 is rapidly done. Therefore, it is possible to
shorten the time when the desired brightness is reached, and to allow the temperature
of the light source lamp 4 11 to increase to the temperature at which blackening ac
cumulated in the discharge space can be eliminated.
[0152] In the projector of this embodiment, when the light source lamp 411 starts to be
turned on, the control device 7 reads a program stored in the storage unit 71, and
performs the same cooling control process as the above-described cooling control
process.
[0153] In Step SI of the cooling control process, the mode acquisition unit 761 acquires the
operation mode at the time of the start of turn-on of the light source lamp 4 11 on the
basis of the input control signal.
[0154] In Step S2, the operation history acquisition unit 762 acquires the operation mode
and the lamp voltage value at the time of previous turn-off of the light source lamp
411.
[0155] In Step S3, the start control unit 763 acquires the start parameters according to the
operation mode and the lamp voltage value acquired in Steps S1 and S2 with reference
to the start parameter table.
[0156] Thereafter, in Step S4, the start control unit 763 controls the operation of the cooling
device 6 (fan 61) on the basis of the limited period and the fan voltage value of the
acquired start parameters.
[0157] Steps S5 to S7 are the same as the above-described processing contents.
[0158] According to the projector of this embodiment described above, in addition to the
same effects as the above-described projector 1, the following effects are obtained.
[0159] The start control unit 763 adjusts the length of the limited period and the limited flow
rate on the basis of the voltage value of lamp electric power before turn-off, such that
the fan voltage having a voltage value according to the limited flow rate is supplied to
the fan 6 1 until the limited period elapses from the turn-on of the light source lamp
411. Thus, when light source lamp 4 11 is turned on in a state where blackening is
likely to be generated, at the time of the start of next turn-on, it is possible to allow the
temperature of the light source lamp 4 11 to reliably increase to the temperature at
which blackening is eliminated. Therefore, it is possible to more reliably suppress the
accumulation of blackening.
[0160] Fourth Embodiment
Next, a fourth embodiment of the invention will be described.
[0161] A projector of this embodiment has the same configuration as the above-described
projector. In the above-described projector, the lamp electric power value, the averagerated
power ratio, and the lamp voltage value before the light source lamp 4 11 is
turned off are stored as the operation history of the light source lamp 411, and the
limited period and the driving information (fan voltage value) are adjusted on the basis
of the lamp electric power value, the average-rated power ratio, and the lamp voltage
value. In contrast, in the projector of this embodiment, at the time of the start of turnon
of the light source lamp 4 11, a lamp current value and a lamp voltage value are
monitored to measure a glow discharge period, and the limited period and the driving
information are adjusted in accordance with the length of the glow discharge period.
From this point, the projector of this embodiment is different from the above-described
projector. In the following description, the same or substantially same parts as the parts
described above are represented by the same reference numerals, and description
thereof will not be repeated.
[0162] Fig. 8 is a block diagram showing the configuration of a projector 1A of this em
bodiment.
[0163] As shown in Fig. 8, the projector 1A of this embodiment has the same configuration
and function as the projector 1, except that a control device 7A, instead of the control
device 7, is provided.
[0164] The control device 7A has the same configuration as the control device 7, except
that, a storage unit 71A and a cooling control unit 76A, instead of the storage unit 7 1
and the cooling control unit 76, are provided. The cooling control unit 76A has the
same configuration as the cooling control unit 76, except that, instead of the operation
history acquisition unit 762, an operation history acquisition unit 762A, a period deter
mination unit 766, and a period acquisition unit 767 are provided.
[0165] The operation history acquisition unit 762A acquires the lamp current value and the
lamp voltage value detected by the detection device 5.
[0166] The period determination unit 766 determines whether or not a transition to an arc
discharge period is made through a glow discharge period after insulation breakdown
has occurred through the application of an igniter pulse by the power supply device 3
at the time of the start of turn-on of the light source lamp 411. Specifically, the period
determination unit 766 monitors the acquired lamp current value, and determines
whether or not the glow discharge period ends (transition to the arc discharge period is
made) on the basis of whether or not the lamp current value reaches a predetermined
limited current value (for example, 3.3 A).
[0167] When the period determination unit 766 determines that the glow discharge period
ends, the period acquisition unit 767 acquires the elapsed time from the start of turn-on
of the light source lamp 411 measured by the timing unit 75 as the length of the glow
discharge period.
[0168] The start control unit 763 acquires the start parameters according to the operation
mode at the time of the start of turn-on of the light source lamp 411 and the length of
the acquired glow discharge period from the storage unit 7 1A. The start control unit
763 puts the cooling device 6 (fan 61) into operation on the basis of the driving in
formation included in the start parameters until the limited period included in the start
parameters elapses from the start of turn-on of the light source lamp 4 11. In this em
bodiment, the start control unit 763 puts the fan 6 1 into operation with a predetermined
voltage value (for example, a minimum voltage value) for putting the fan 6 1 into
operation until the start parameters are acquired.
[0169] The storage unit 71A stores the same contents as the stored content of the storage
unit 71, except that a start parameter table different from the above-described start
parameter table is stored.
[0170] That is, the storage unit 71A stores a start parameter table, in which the length of the
glow discharge period is set in association with the limited period and the driving in
formation (fan voltage value), for each operation mode at the time of the start of turnon
of the light source lamp 411.
[0171] Fig. 9 is a diagram showing an example of a start parameter table stored in the
storage unit 7 1A. Fig. 9 shows a start parameter table which is applied when the
operation mode at the time of the start of turn-on of the light source lamp 4 11 is the
high power mode.
[0172] For example, in the start parameter table which is applied when the light source lamp
4 11 is turned on in the high power mode at the time of the start of turn-on, as shown in
Fig. 9, the start parameters of the patterns A and B described above are set for each
length of the glow discharge period.
[0173] Of these, in the start parameters of the pattern A, a constant fan voltage value is set,
and a different limited period is set for each length of the glow discharge period. In the
pattern A, the longer the glow discharge period, the longer the limited period is set.
[0174] In the start parameters of the pattern B, a constant limited period is set, and a
different fan voltage value is set for each length of the glow discharge period. In the
pattern B, the longer the glow discharge period, the lower the fan voltage value is set.
[0175] If the glow discharge period included in the start period after insulation breakdown
of the light source lamp 4 11 is long, the period in which the electrodes receive a
sputter by ions is extended, and the amount of blackening to be generated is likely to
increase. For this reason, as described above, when the glow discharge period is long, a
long limited period or a low fan voltage value is set, such that cooling of the light
source lamp 4 11 by the cooling device 6 is temporarily limited, and the temperature of
the light source lamp 411 rapidly increases to such an extent that blackening is
eliminated.
[0176] Fig. 10 is a flowchart showing a cooling control process which is performed by the
control device 7A at the time of the start of turn-on of the light source lamp 411.
[0177] In this projector 1A, when the light source lamp 4 11 starts to be turned on, the
control device 7A reads a program stored in the storage unit 71A and performs the
following cooling control process.
[0178] In this cooling control process, as shown in Fig. 10, first, the start control unit 763
drives the fan 6 1 with a predetermined voltage (Step SA1).
[0179] The mode acquisition unit 761 acquires the operation mode at the time of the start of
turn-on of the light source lamp 411 (Step SI). The operation history acquisition unit
762A acquires the lamp current value detected by the detection device 5 as the
operation history of the light source lamp 411 (Step SA2).
[0180] Next, the period determination unit 766 monitors the acquired lamp current value,
and determines whether or not the lamp current value exceeds a predetermined limited
current value to determine whether or not the glow discharge period ends (Step SA3).
[0181] If it is determined that the glow discharge period does not end, the control device 7A
repeats the determination process in Step SA3.
[0182] If it is determined that the glow discharge period ends, the period acquisition unit
767 acquires the elapsed time from the timing unit 75 for measuring the elapsed time
from the start of turn-on of the light source lamp 411 (the start of supply of lamp
electric power) as the glow discharge period (Step SA4).
[0183] Next, the start control unit 763 acquires the start parameter (limited period and
driving information) corresponding to the acquired operation mode and glow discharge
period from the storage unit 71A (Step SA5), and controls the driving of the cooling
device 6 on the basis of the acquired driving information until the limited period
elapses (Step SA6).
[0184] Thereafter, the same process as Steps S5 to S7 is performed.
[0185] According to the projector 1A of this embodiment described above, in addition to the
same effects of the above-described projector 1, the following effects are obtained.
[0186] The start control unit 763 adjusts the length of the limited period and the limited flow
rate on the basis of the glow discharge period, such that the fan voltage having a
voltage value according to the limited flow rate is supplied to the fan 6 1 until the
limited period elapses from the turn-on of the light source lamp 411. Thus, at the time
of the start of turn-on of the light source lamp 4 11, it is possible to allow the tem
perature of the light source lamp 4 11 to reliably increase to the temperature at which
accumulated blackening is eliminated. Therefore, it is possible to more reliably
suppress the accumulation of blackening.
[0187] Fifth Embodiment
Next, a fifth embodiment of the invention will be described.
[0188] A projector of this embodiment performs the cooling control process (see Fig. 4)
described in the first to third embodiments if the cumulative turn-on time of the light
source lamp 4 11 is smaller than a predetermined time, and performs the cooling
control process (see Fig. 10) described in the fourth embodiment if the cumulative
turn-on time is equal to or greater than the predetermined time. From this point, the
projector of this embodiment is different from the projector 1 or 1A. In the following
description, the same or substantially same parts as the parts described above are rep
resented by the same reference numerals, and description thereof will not be repeated.
[0189] Fig. 11 is a block diagram showing the configuration of a projector IB of this em
bodiment.
[0190] As shown in Fig. 11, the projector IB of this embodiment has the same configuration
and function as the projector 1, except that a control device 7B, instead of the abovedescribed
control device 7, is provided. The control device 7B has the same con
figuration and function as the control device 7, except that, instead of the storage unit
71, the main control unit 72, the timing unit 75, and the cooling control unit 76, storage
unit 7 IB, main control unit 72B, timing unit 75B, and cooling control unit 76B are
provided.
[0191] The storage unit 7 IB stores the same content as the content stored in each of the
above-described storage units 7 1 and 7 1A. For example, the storage unit 7 IB stores the
driving parameter table and the start parameter table stored in the storage unit 7 1
described in the above-described first to third embodiments, and also stores the start
parameter table stored in the storage unit 71A described in the above-described fourth
embodiment. The storage unit 7 IB also stores information representing the operation
history of the above-described light source lamp 411.
[0192] The main control unit 72B performs the process which is performed by the main
control unit 72, and also allows the timing unit 75B to measure the cumulative turn-on
time of the light source lamp 4 11 in accordance with the turn-on and turn-off of the
light source lamp 411.
[0193] The timing unit 75B performs the process which is performed by the timing unit 75,
and also measures the cumulative turn-on time of the light source lamp 411 under the
control of the main control unit 72B.
[0194] The cooling control unit 76B performs control such that the cooling device 6 sends
cooling air for cooling the constituent parts (in particular, the light source lamp 4 11) of
the projector 1. The cooling control unit 76B provides the above-described limited
period at the time of the start of turn-on of the light source lamp 411, such that the tem
perature of the light source lamp 411 rapidly increases, the time when the desired
brightness is reached is shortened, and blackening generated in the discharge space S is
eliminated. At this time, the cooling control unit 76B switches and performs the
cooling control process described in one of the above-described first to third em
bodiments and the cooling control process described in the above-described fourth em
bodiment under a predetermined condition. In this embodiment, the predetermined
condition refers to whether or not the cumulative turn-on time of the light source lamp
4 11 is equal to or greater than a predetermined time. If the cumulative turn-on time is
smaller than the predetermined time, the cooling control process described in one of
the first to third embodiments is performed. If the cumulative turn-on time is equal to
or greater than the predetermined time, the cooling control process described in the
fourth embodiment is performed.
[0195] Although in this embodiment, a case has been described where the cooling control
unit 76B performs the cooling control process described in the third embodiment, the
cooling control process described in the first or second embodiment may be performed.
[0196] The cooling control unit 76B has a condition determination unit 768, a mode ac
quisition unit 761, an operation history acquisition unit 762B, a period determination
unit 766, a period acquisition unit 767, a start control unit 763, an elapsed time deter
mination unit 764, and a normal control unit 765.
[0197] The condition determination unit 768 determines the above-described condition at
the time of the start of turn-on of the light source lamp 411, and outputs a control
signal representing the determination result to each functional unit constituting the
cooling control unit 76B. In this embodiment, the condition determination unit 768 de
termines whether or not the cumulative turn-on time of the light source lamp 411
measured by the timing unit 75B is equal to or greater than a predetermined time (for
example, 2000 hours).
[0198] The operation history acquisition unit 762B changes the operation history of the light
source lamp 411 to be acquired on the basis of the determination result of the condition
determination unit 768. For example, when it is determined that the cumulative turn-on
time is smaller than the predetermined time, the operation history acquisition unit
762B acquires the operation history (the lamp voltage value and the operation mode at
the time of previous turn-off) of the light source lamp 411 stored in the storage unit
7 IB. When it is determined that the cumulative turn-on time is equal to or greater than
the predetermined time, the operation history acquisition unit 762B acquires the lamp
current value and the lamp voltage value detected by the detection device 5.
[0199] When it is determined that the cumulative turn-on time is equal to or greater than the
predetermined time, the period determination unit 766 and the period acquisition unit
767 function as described above.
[0200] When it is determined that the cumulative turn-on time is smaller than the prede
termined time, the start control unit 763 acquires the start parameters based on in
formation (the lamp voltage value and the operation mode at the time of previous turnoff)
acquired by the operation history acquisition unit 762B with reference to the start
parameter table of the storage unit 7 IB.
[0201] When it is determined that the cumulative turn-on time is equal to or greater than the
predetermined time, the start control unit 763 acquires the start parameters according
to the length of the glow discharge period acquired by the period acquisition unit 767
with reference to the start parameter table of the storage unit 7 IB.
[0202] The start control unit 763 performs control such that a voltage according to the fan
voltage value included in the start parameters is supplied to the fan 6 1 until the elapsed
time determination unit 764 determines that the limited period included in the acquired
start parameter has elapsed.
[0203] Thereafter, if the elapsed time determination unit 764 determines that the limited
period has elapsed, operation control of the fan 6 1 is performed on the basis of the
driving parameters by the normal control unit 765.
[0204] When the light source lamp 411 starts to be turned on, the cooling control process
which is performed when the control device 7B reads and executes a program stored in
the storage unit 7 IB includes the cooling control process described in the third em
bodiment and the cooling control process described in the fourth embodiment. As
described above, any cooling control process is performed on the basis of the deter
mination result by the condition determination unit 768, thus description thereof will
not be repeated.
[0205] The reason for which the cooling control process is switched is as follows.
[0206] In the case of normal turn-on, if the arc length between the electrodes E is shortened,
the current value of lamp electric power increases, and blackening is likely to be
generated. Meanwhile, in the glow discharge period, when the arc length is short, a
transition to the arc discharge is easily made, such that the glow discharge period is
reduced, and the generation of blackening by a sputter or the like is suppressed. The
importance of the factor for which blackening is likely to be generated changes
depending on the state of the light source lamp.
[0207] In the comparatively first half period in the lifetime of the light source lamp 4 11, an
influence of the arc length on blackening being likely to be generated increases
compared to the length of the glow discharge period. In the comparatively second half
period, the relationship is reversed.
[0208] Thus, the cooling control process according to the former and the cooling control
process according to the latter are appropriately switched with the cumulative turn-on
time of the light source lamp 4 11 as index, thereby effectively suppressing the accu
mulation of blackening in the light source lamp 411.
[0209] According to the projector IB of this embodiment described above, in addition to the
same effects as the above-described projector 1 or 1A, the following effects are
obtained.
[0210] When the cumulative turn-on time of the light source lamp 4 11 is smaller than the
predetermined time, the start parameters are acquired in accordance with lamp electric
power (the lamp voltage value and the operation mode at the time of previous turnoff).
When the cumulative turn-on time is equal to or greater than the predetermined
time, the start parameters according to the length of the glow discharge period are
acquired. The start control unit 763 controls the driving of the fan 6 1 on the basis of
the start parameters, thereby performing effective cooling control according to the state
of the light source lamp 411. Therefore, it is possible to more reliably suppress the ac
cumulation of blackening.
[021 1] As described above, the cooling control process which is performed when it is de
termined that the cumulative turn-on time is smaller than the predetermined time may
be substituted with the cooling control process described in the first or second em
bodiment.
[0212] Sixth Embodiment
Next, a sixth embodiment of the invention will be described.
[0213] A projector of this embodiment has the same configuration as the above-described
projector IB. In the projector IB, the cooling control process to be performed is
switched on the basis of the cumulative turn-on time of the light source lamp 4 11. In
contrast, in the projector of this embodiment, if the voltage value of lamp electric
power at the time of normal turn-on is smaller than a predetermined value, the cooling
control process described in one of the above-described first to third embodiments is
performed. If the voltage value is equal to or greater than the predetermined value, the
cooling control process described in the above-described fourth embodiment is
performed. From this point, the projector of this embodiment is different from the
projector IB. In the following description, the same or substantially same parts as the
parts described above are represented by the same reference numerals, and description
thereof will not be repeated.
[0214] The projector of this embodiment has the same configuration and function as the
above-described projector IB.
[0215] When the projector is powered off, the main control unit 72B stores the lamp voltage
value detected by the detection device 5 and the operation mode of the light source
lamp 4 11 in the storage unit 7 IB as the operation history of the light source lamp 411.
As in the above-described third embodiment, the average lamp voltage value in the
predetermined period when the projector is powered off may be stored.
[0216] In this embodiment, the condition determination unit 768 acquires the lamp voltage
value at the time of previous turn-off stored in the storage unit 7 IB at the time of the
start of turn-on of the light source lamp 411, and determines whether or not the lamp
voltage value is equal to or greater than a predetermined value (for example, 100 V).
The condition determination unit 768 outputs a control signal representing the deter
mination result to each functional unit constituting the cooling control unit 76B.
[0217] If the condition determination unit 768 determines that the lamp voltage value is
smaller than the predetermined value, the operation history acquisition unit 762B
acquires the operation history (the lamp voltage value and the operation mode) of the
light source lamp 411 stored in the storage unit 7 IB. If it is determined that the lamp
voltage value is equal to or greater than the predetermined value, the operation history
acquisition unit 762B acquires the lamp current value and the lamp voltage value
detected by the detection device 5.
[0218] When it is determined that the lamp voltage value is equal to or greater than the pre
determined value, the period determination unit 766 and the period acquisition unit 767
function as described above.
[0219] When it is determined that the lamp voltage value is smaller than the predetermined
value, the start control unit 763 acquires the start parameters based on information
acquired by the operation history acquisition unit 762B. When it is determined that the
lamp voltage value is equal to or greater than the predetermined value, the start control
unit 763 acquires the start parameters according to the length of the glow discharge
period acquired by the period acquisition unit 767.
[0220] The start control unit 763 performs control such that a voltage according to the fan
voltage value included in the start parameters is applied to the fan 6 1 until the elapsed
time determination unit 764 determines that the limited period included in the acquired
start parameters has elapsed.
[0221] Thereafter, if the elapsed time determination unit 764 determines that the limited
period has elapsed, operation control of the fan 6 1 is performed on the basis of the
driving parameters by the normal control unit 765.
[0222] As in the above-described projector IB, the cooling control process which is
performed when the light source lamp 411 starts to be turned on includes the cooling
control process described in the third embodiment and the cooling control process
described in the fourth embodiment. Any cooling control process is performed on the
basis of the determination result of the condition determination unit 768.
[0223] According to the projector of this embodiment described above, the same effects as
the above-described projector IB can be obtained.
[0224] That is, if the voltage value of lamp electric power at the time of normal turn-on (the
voltage value of lamp electric power at the time of previous turn-off) is smaller than
the predetermined value, the start parameters according to the voltage value of lamp
electric power and the operation mode are acquired. If the voltage value is equal to or
greater than the predetermined value, the start parameters according to the length of the
glow discharge period are acquired. The start control unit 763 controls the driving of
the fan 6 1 on the basis of the start parameters, thereby performing effective cooling
control according to the state of the light source lamp 411. Therefore, it is possible to
more reliably suppress the accumulation of blackening.
[0225] As in the above-described fifth embodiment, the cooling control process which is
performed when it is determined that the lamp voltage value before previous turn-off is
smaller than the predetermined value may be substituted with the cooling control
process described in the first or second embodiment.
[0226] Seventh Embodiment
Next, a seventh embodiment of the invention will be described.
[0227] A projector of this embodiment has the same configuration as the above-described
projector IB, but the cooling control process to be performed is switched in accordance
with whether or not the turn-on time of the light source lamp 4 11 at the time of
previous turn-on is within a predetermined time. In the following description, the same
or substantially same parts as the parts described above are represented by the same
reference numerals, and description thereof will not be repeated.
[0228] The projector of this embodiment has the same configuration and function as the
above-described projector IB.
[0229] The main control unit 72B performs control such that the timing unit 75B measures
the time (previous turn-on time) when the light source lamp 4 11 is turned on and then
turned off. When the projector is powered off, the main control unit 72B stores the
previous turn-on time in the storage unit 7IB.
[0230] In this embodiment, the condition determination unit 768 acquires the previous turnon
time stored in the storage unit 7IB at the time of the start of turn-on of the light
source lamp 411, and determines whether or not the previous turn-on time is equal to
or greater than a predetermined time. The condition determination unit 768 outputs a
control signal representing the determination result to each functional unit constituting
the cooling control unit 76B.
[0231] If it is determined that the previous turn-on time is equal to or greater than the prede
termined time, the operation history acquisition unit 762B acquires the operation
history (the lamp voltage value and the operation mode) of the light source lamp 411
stored in the storage unit 7IB. If it is determined that the previous turn-on time is
smaller than the predetermined time, the operation history acquisition unit 762B
acquires the lamp current value and the lamp voltage value detected by the detection
device 5.
[0232] When the previous turn-on time is smaller than the predetermined time, the period
determination unit 766 and the period acquisition unit 767 function as described above.
[0233] When it is determined that the previous turn-on time is equal to or greater than the
predetermined time, the start control unit 763 acquires the start parameters based on in
formation acquired by the operation history acquisition unit 762B. When it is de
termined that the previous turn-on time is smaller than the predetermined time, the start
control unit 763 acquires the start parameters according to the length of the glow
discharge period acquired by the period acquisition unit 767.
[0234] The start control unit 763 performs control such that a voltage according to the fan
voltage value included in the start parameters is supplied to the fan 6 1 until the elapsed
time determination unit 764 determines that the limited period included in the acquired
start parameters has elapsed.
[0235] Thereafter, if the elapsed time determination unit 764 determines that the limited
period has elapsed, operation control of the fan 6 1 is performed on the basis of the
driving parameters by the normal control unit 765.
[0236] As in the above-described projector IB, the cooling control process which is
performed when the light source lamp 411 starts to be turned on includes the cooling
control process described in the third embodiment and the cooling control process
described in the fourth embodiment. Any cooling control process is performed on the
basis of the determination result of the condition determination unit 768.
[0237] According to the projector of this embodiment described above, the same effects as
the above-described projector IB can be obtained.
[0238] That is, if the turn-on time (the turn-on time before turn-off) of the light source lamp
4 11 at the time of previous turn-on is equal to or greater than the predetermined time, it
is determined that the turn-on and turn-off of the light source lamp 411 are not
frequently performed, and the start parameters according to the voltage value of lamp
electric power and the operation mode are acquired. If the turn-on time is smaller than
the predetermined time, it is determined that turn-on and turn-off are frequently
performed, and the start parameters according to the length of the glow discharge
period are acquired. The start control unit 763 controls the driving of the fan 6 1 on the
basis of the start parameters, thereby performing effective cooling control according to
the state of the light source lamp 411. Therefore, it is possible to more reliably
suppress the accumulation of blackening.
[0239] As in the above-described fifth and sixth embodiments, the cooling control process
which is performed when it is determined that the previous turn-on time is equal to or
greater than the predetermined time may be substituted with the cooling control
process described in the first or second embodiment.
[0240] Eighth Embodiment
Next, an eighth embodiment of the invention will be described.
[0241] A projector of this embodiment has the same configuration and function as the
above-described projector 1, 1A, or IB, is provided for the restart (hot restart) of the
light source lamp, and has the further configuration and function of adjusting the
limited period and the driving information on the basis of the lamp voltage value after
insulation breakdown at the time of the start of turn-on. In the following description,
the same or substantially same parts as the parts described above are represented by the
same reference numerals, and description thereof will not be repeated.
[0242] The projector of this embodiment has the same configuration and function as the
projector IB. The storage unit 7IB further stores a restart parameter table which is
applied when the light source lamp 4 11 is restarted.
[0243] The restart parameter table is set for each operation mode at the time of the restart of
the light source lamp 4 11. In these restart parameter tables, restart parameters are set in
associating the lamp voltage value after insulation breakdown of the light source lamp
411 with the limited period and the driving information (fan voltage value).
[0244] Fig. 12 is a diagram showing an example of a restart parameter table for restart. Fig.
12 shows a restart parameter table which is applied when the light source lamp 4 11 is
restarted in the high power mode.
[0245] For example, in the restart parameter table which is applied when the light source
lamp 4 11 is restarted in the high power mode, as shown in Fig. 12, the restart p a
rameters of the patterns A and B are set for each lamp voltage value after insulation
breakdown.
[0246] Of these, in the restart parameters of the pattern A, a constant fan voltage value is set,
and a different limited period is set for each lamp voltage value. In the pattern A, the
higher the lamp voltage value, the shorter the limited period is set.
[0247] In the restart parameters of the pattern B, a constant limited period is set, and a
different fan voltage value is set for each lamp voltage value. In the pattern B, the
higher the lamp voltage value, the higher the fan voltage value is set.
[0248] The reason for which the limited period and the fan voltage value are set is as
follows.
[0249] While, at the time of the restart of the light source lamp 4 11, an increase in power
and temperature is rapidly done, it is necessary to control the operation of the cooling
device 6 such that the temperature of the light source lamp 411 does not increase ex
cessively.
[0250] The temperature of the light source lamp 411 after insulation breakdown corresponds
to the lamp voltage value at a rise time immediately after turn-on and glow discharge.
For this reason, it is possible to recognize the temperature of the light source lamp 411
with the lamp voltage value at the rise time as index. For example, when the lamp
voltage value is high, it is determined that the temperature of the light source lamp 411
is high.
[0251] On the other hand, at the time of the restart, the internal pressure in the light source
lamp 411 increases, such that insulation breakdown occurs with difficulty. In order to
cope with this situation, during a predetermined period after the restart, the flow rate of
cooling air sent to the light source lamp 411 may increase.
[0252] Thus, the restart parameters are applied in accordance with the lamp voltage value
immediately after glow discharge to control the driving of the cooling device 6 (fan
61), thereby preventing an excessive increase in temperature of the light source lamp
411.
[0253] In this projector, when the light source lamp 4 11 is restarted, the same cooling
control process as the above-described cooling control process is performed. This
cooling control process is performed when it is determined to be restarted on the basis
of the lamp voltage value after insulation breakdown between the electrodes E of the
light source lamp 411. When it is determined to be not restarted, the cooling control
process described in one of the fifth to seventh embodiments is performed under the
above-described condition.
[0254] In the cooling control process, after Steps SA1 and SI described above, in Step S2,
the operation history acquisition unit 762B acquires a lamp voltage value after in
sulation breakdown of the light source lamp 411.
[0255] Next, in Step S3, the start control unit 763 references the restart parameter table of
the acquired operation mode, and acquires the restart parameters according to the
acquired lamp voltage value.
[0256] In Step S4, the start control unit 763 controls the operation of the cooling device 6
(fan 61) on the basis of the driving information included in the parameters until the
limited period included in the restart parameters elapses.
[0257] Thereafter, the same process as Steps S5 to S7 is performed.
[0258] According to the projector of this embodiment described above, in addition to the
same effects as the above-described projector IB, the following effects are obtained.
[0259] When the light source lamp 4 11 is restarted, the start control unit 763 adjusts the
length of the limited period and the limited flow rate on the basis of the voltage value
of lamp electric power after insulation breakdown, and performs control such that the
fan voltage having a voltage value according to the limited flow rate is supplied to the
fan 6 1 until the limited period elapses from the restart of the light source lamp 411.
Thus, at the time of the restart of the light source lamp 4 11 at which an increase in
power and temperature is rapidly done, it is possible to suppress an excessive increase
in temperature of the light source lamp. Therefore, it is possible to stabilize the turn-on
of the light source lamp 4 11, to suppress the occurrence of devitrification and blowing,
and to achieve the long lifetime of the light source lamp 411.
[0260] Ninth Embodiment
Next, a ninth embodiment of the invention will be described.
[0261] While a projector of this embodiment has the same configuration as the abovedescribed
projector, in the projector of this embodiment, a first start period im
mediately after the restart of the light source lamp 4 11, a second start period corre
sponding to a rise period of the light source lamp 411 after the first start period, and a
normal period, in which cooling air at a set flow rate is sent, after the second start
period are provided, and the limited period and driving information of each start period
are adjusted. In the following description, the same or substantially same parts as the
parts described above are represented by the same reference numerals, and description
thereof will not be repeated.
[0262] Fig. 13 is a diagram showing the relationship between transition (fine solid line) of a
power value at the time of the restart of the light source lamp 4 11 of this embodiment
and transition (bold solid line) of a fan voltage value. In Fig. 13, the transition of the
fan voltage value to be applied to the fan 6 1 by the cooling control process at the time
of the restart in the above-described eighth embodiment is indicated by a dotted line.
[0263] The projector of this embodiment has the same configuration and function as the
above-described projector IB. The storage unit 7 IB further stores a first parameter
table and a second parameter table which are applied at the time of the restart of the
light source lamp 411.
[0264] That is, the storage unit 7 IB stores a first parameter table in which a first parameter
to be applied in a first start period Tl shown in Fig. 13 is set, a second parameter table
in which a second parameter to be applied in a second start period T2 is set, and a
driving parameter table in which driving parameters to be applied in a normal period
T3 are set.
[0265] Of these, in the first parameter, a comparatively high fan voltage value is set as
driving information. In the second parameter, a comparatively high fan voltage value is
set as driving information. In these parameters, a limited period according to the state
of the light source lamp 4 11 at the time of the restart is set.
[0266] The start control unit 763 controls the fan 6 1 in accordance with the parameters at the
time of the restart of the light source lamp 411, thereby efficiently performing tem
perature control of the light source lamp 411.
[0267] According to the projector of this embodiment described above, in addition to the
same effects as the above-described projector, it is possible to perform operation
control of the fan 6 1 in detail, thereby more effectively performing temperature control
of the light source lamp 411.
[0268] Modifications of Embodiments
The invention is not limited to the above-described embodiments, modifications, im
provements, and the like within the scope capable of achieving the object of the
invention are included in the invention.
[0269] Although in the above-described embodiments, the start control unit 763 acquires the
parameters, in which the length of the limited period and the voltage value of the fan
voltage are set, from the storage unit, and adjusts the length of the limited period and
the limited flow rate which is the flow rate of cooling air sent to the light source lamp
411 within the limited period, the invention is not limited thereto. That is, the parameters
may be calculated in accordance with the operation state of the light source
lamp 4 11 by an arithmetic operation.
[0270] Although in the above-described embodiments, main control unit 72 or 72B stores
the lamp electric power value, the average -rated power ratio, and the lamp voltage
value of the light source lamp 411 before turn-off in the storage unit 7 1 or 7 IB as the
operation history of the light source lamp 411, and the start control unit 763 adjusts the
length of the limited period and the limited flow rate in accordance with the lamp
electric power value, the average-rated power ratio, and the lamp voltage value, the
invention is not limited thereto. That is, other kinds of information may be acquired as
an operation history insofar as the information can be used to determine the blackening
accumulation state in the light source lamp 411.
[0271] Although in the above-described embodiments, the cooling device 6 has the fan 6 1
which sends cooling air for cooling the light source lamp 411, and the cooling control
unit 76, 76A, or 76B applies the fan voltage value for driving the fan 6 1 to the power
supply device 3, the invention is not limited thereto. For example, the cooling device
may include regulation unit, such as a louver, which adjusts the flow rate of cooling air
sent to the light source lamp 411, and the cooling control unit may control the
operation of the regulation unit, thereby adjusting the flow rate of cooling air sent to
the light source lamp 4 11. In this case, the fan 6 1 may be driven with a constant fan
voltage value or may be driven along with driving control of the fan described above.
In this case, it is possible to adjust the flow rate to be sent to the light source lamp 411
in more detail.
[0272] Although in the above-described embodiments, the cooling device 6 sends cooling
air as a cooling fluid, the invention is not limited thereto. For example, a cooling
solvent, such as ethylene glycol, may be used as a cooling fluid to cool the light source
lamp 411 insofar as the insulation of the light source lamp 4 11 is appropriately made.
[0273] Although in the above-described embodiments, the fan 6 1 is driven on the basis of
the driving information set in the parameters for the limited period, the invention is not
limited thereto. That is, the fan 6 1 may be stopped.
[0274] Although in the above-described embodiments, the voltage value of the fan voltage is
constant for each limited period, the invention is not limited thereto. That is, the
voltage value may be changed. For example, the voltage value may increase suc
cessively or in a stepwise manner in the second half of the limited period, and when
the limited period ends, the fan voltage may be applied such that cooling air at the set
flow rate is sent.
[0275] Although in the fifth to seventh embodiments, the predetermined condition refers to
the cumulative turn-on time of the light source lamp 411, the lamp voltage value at the
time of previous turn-off, and the previous turn-on time, the invention is not limited
thereto. That is, the cooling control process to be performed may be switched under
other conditions.
[0276] Instead of switching the cooling control process to be performed under the
conditions, the factor for blackening to be considered may be weighted in accordance
with the state of the light source lamp 411, and at least one of the limited period and
the limited flow rate may be adjusted on the basis of the weight.
[0277] Although in the above-described embodiments, the parameters of the pattern A in
which the voltage value of the fan voltage is constant and the parameters of the pattern
B in which the length of the limited period is constant are set in the parameter table,
the invention is not limited thereto. That is, the parameters of only one of the patterns
A and B may be set. The parameters are not limited to the above-described parameters,
and parameters may be set such that the length of the limited period and the fan voltage
value (consequently, the limited flow rate) differ in accordance with the lamp electric
power value, the average-rated power value, and the lamp voltage value before turnoff.
Industrial Applicability
[0278] The invention can be used in a projector, and in particular, can be appropriately used
in a projector having a light source lamp in which a pair of electrodes and a discharge
material are sealed.
Reference Signs List
[0279] 1, 1A, IB: projector, 6: cooling device (cooling unit), 61: fan, 71, 71A, 71B: storage
unit, 74: lighting control unit, 411: light source lamp, 763: start control unit (start
control unit), 765: normal control unit (normal control unit), E (El, E2): electrode, S:
discharge space.
PCT/JP2011/007076
Claims
A projector comprising:
a light source lamp;
a lighting control unit adapted to supply a lamp electric power to turn
on the light source lamp;
a cooling unit adapted to send a cooling fluid to cool the light source
lamp; and
a start control unit adapted to, from the start of turn-on of the light
source lamp until a predetermined period elapses, adjust at least one of
the length of the predetermined period and a limited flow rate, which is
the flow rate of the cooling fluid per unit time sent from the cooling
unit within the predetermined period, on the basis of an operation
history of the light source lamp to control the operation of the cooling
unit.
The projector according to claim 1, further comprising:
a normal control unit adapted to control the cooling unit such that the
cooling fluid at a set flow rate set in advance in accordance with lamp
electric power is sent to the light source lamp after the predetermined
period has elapsed.
The projector according to claim 1 or 2,
wherein the start control unit adjusts at least one of the length of the
predetermined period and the limited flow rate in accordance with the
operation history and lamp electric power supplied to the light source
lamp.
The projector according to claim 3,
wherein the operation history is the power value of lamp electric power
supplied to the light source lamp before the light source lamp is turned
off.
The projector according to claim 3,
wherein the operation history is the ratio of a rated power value of the
light source lamp and an average power value of lamp electric power
supplied to the light source lamp before the light source lamp is turned
off.
The projector according to claim 3,
wherein the operation history is the voltage value of lamp electric
power supplied to the light source lamp before the light source lamp is
turned off.
WO 2012/095926 PCT/JP2011/007076
[Claim 7] The projector according to claim 1 or 2,
wherein the light source lamp has a discharge space in which a pair of
electrodes and a discharge material are sealed,
after insulation breakdown in which insulation between a pair of
electrodes is broken due to lamp electric power supplied by the lighting
control unit, the light source lamp is turned on through a glow
discharge period in which glow discharge is generated between a pair
of electrodes and an arc discharge period in which arc discharge is
generated between a pair of electrodes, and
the start control unit adjusts at least one of the length of the prede
termined period and the limited flow rate in accordance with the length
of the glow discharge period.
[Claim 8] The projector according to claim 3,wherein
the light source lamp has a discharge space in which a pair of
electrodes and a discharge material are sealed,
after insulation breakdown in which insulation between a pair of
electrodes is broken due to lamp electric power supplied by the lighting
control unit, the light source lamp is turned on through a glow
discharge period in which glow discharge is generated between a pair
of electrodes and an arc discharge period in which arc discharge is
generated between a pair of electrodes, and
the cooling control unit adjusts at least one of the length of the prede
termined period and the limited flow rate in accordance with lamp
electric power if a cumulative turn-on time of the light source lamp is
smaller than a predetermined time, and adjusts at least one of the length
of the predetermined period and the limited flow rate in accordance
with the length of the glow discharge period if the cumulative turn-on
time is equal to or greater than the predetermined time.
[Claim 9] The projector according to claim 3, wherein
the light source lamp has a discharge space in which a pair of
electrodes and a discharge material are sealed,
after insulation breakdown in which insulation between a pair of
electrodes is broken due to lamp electric power supplied by the lighting
control unit, the light source lamp is turned on through a glow
discharge period in which glow discharge is generated between a pair
of electrodes and an arc discharge period in which arc discharge is
generated between a pair of electrodes, and
the cooling control unit adjusts at least one of the length of the predeWO
2012/095926 PCT/JP2011/007076
termined period and the limited flow rate in accordance with lamp
electric power if the voltage value of lamp electric power supplied to
the light source lamp before the light source lamp is turned off is lower
than a predetermined value, and adjusts at least one of the length of the
predetermined period and the limited flow rate in accordance with the
length of the glow discharge period if the voltage value is equal to or
greater than the predetermined value.
[Claim 10] The projector according to claim 3, wherein
the light source lamp has a discharge space in which a pair of
electrodes and a discharge material are sealed,
after insulation breakdown in which insulation between a pair of
electrodes is broken due to lamp electric power supplied by the lighting
control unit, the light source lamp is turned on through a glow
discharge period in which glow discharge is generated between a pair
of electrodes and an arc discharge period in which arc discharge is
generated between a pair of electrodes, and
the cooling control unit adjusts at least one of the length of the prede
termined period and the limited flow rate in accordance with lamp
electric power if the turn-on time of the light source lamp immediately
before the light source lamp is turned off is equal to or greater than a
predetermined time, and adjusts at least one of the length of the prede
termined period and the limited flow rate in accordance with the length
of the glow discharge period if the turn-on time is smaller than the pre
determined time.
[Claim 11] The projector according to any one of claims 1 to 10, wherein
the light source lamp has a discharge space in which a pair of
electrodes and a discharge material are sealed, and
the start control unit adjusts at least one of the length of the prede
termined period and the limited flow rate on the basis of, as the
operation history, the voltage value of lamp electric power supplied to
the light source lamp after insulation breakdown in which insulation is
broken between a pair of electrodes.
[Claim 12] The projector according to any one of claims 1 to 11, further
comprising:
a storage unit for storing the operation history of the light source lamp
in association with driving information of the cooling unit according to
the length of the predetermined period and the limited flow rate,
wherein
WO 2012/095926 PCT/JP2011/007076
the start control unit acquires the length of the predetermined period
and the driving information according to the operation history of the
light source lamp from the storage unit, and puts the cooling unit into
operation.
[Claim 13] The projector according to claim 12, wherein
the cooling unit includes a fan which sends the cooling fluid, and
the driving information is a fan voltage value which is supplied to the
fan.