[Designation of Document] Description
[Title of the Invention] IMAGE DISPLAY APPARATUS AND
METHOD OF CONTROLLING IMAGE DISPLAY APPARATUS
[Technical Field]
[00011
The present invention relates to an image display
apparatus and a method of controlling the image display
apparatus.
d
[Background Art]
[00021
In the related art, there is a display apparatus that
includes a light source, a first spatial light modulator
installed to modulate light from the light source, a display
screen including a second spatial light modulator, and an
optical system configured to project the light modulated by
the first spatial light modulator to a firstsurface of the
display screen (for example, PTL I). In such a display
apparatus, an image with high contrast can be displayed with
a broad dynamic range.
[Citation List1
[Patent Literature]
[00031
[PTL 11 JP-T-2004-523001
[Summary of Invention]
[Technical Problem]
[00041
In the display apparatus disclosed in PTL 1, however,
even when the second spatial light modulator is matched with
the first spatial light modulator for light adjustment, an
influence of illumination on peripheral pixels of matched
pixels occurs. That is, since pixels in the periphery of the
second spatial light modulator are also illuminated by
expansion of illumination light radiated from the first
spatial light modulator, a desired image may not be output in
some cases. For example, the brightness of image light
radiated fromthe second spatial light modulator deteriorates
in some cases. Accordingly, it was necessary to perform
control in consideration of the expansion of the illumination
light from the first spatial light modulator. Hereinafter,
a "spatial light modulator" is referred to as a "light
modulation device."
[Solution to Problem]
[00051
The invention has been made in order to solve at least
a part of the problems described above and can be implemented
as the following forms or application examples.
[00061
[Application Example 11 An image display apparatus
according to this application example includes: a first light
modulation device that includes a plurality of display pixels
and modulates llght based on input first image information;
an illumination unit that includes a plurality of light
adjustment elements andemits adjustedlighttothe first light
modulation device; an illumination distribution storage unit
that stores an illumination range in which the light emitted
from the light adjustment elements illuminates the display
pixels of the first light modulation device; and a light
adjustment information decision unit that decides light
'I
adjustment information to control the light adjustment
elements of the illumination unit based on a feature amount
of the first image information corresponding to the display
pixels of the illumination range stored in the illumination
distribution storage unit.
[00071
The image display apparatus includes the first light
modulation device including the display pixels and the
illumination unit including the light adjustment elements.
The light adjustment information decision unit decides the
light adjustment information to control the light adjustment
elements of the illumination unit based on the feature amount
of the first lrnage information according to the display pixels
of the illumination range of the first light modulation device
illuminating the llght adjusted by the light adjustment
elements. Accordingly, the illumination unit can perform the
light adjustment in considerationof the feature amount of the
first pixel information corresponding to the illumination
range of the illumination light.
[00081
[Application Example 21 In the image display apparatus
according to the application example, the illumination
distribution storage unit further stores distribution
information of an illumination intensitywithwhich the light
emitted from the light adjustment elements illuminates the
displaypixelsofthe first light modulationdevice. The image
dlsplay apparatus further includes: an illumination value
calculation unit that calculates an illumination value of the
light arriving at each of the display pixels of the first light
modulation device based on the light adjustment information
of the illumination unit and the distribution information of
the illumination intensity; and an image information
generation unit that generates second image information to be
set in the first light modulation device based on the
illumination value calculated by the illumination value
calculation unit and the first image information.
[00091
In the image display apparatus, the illumination value
calculation unit calculates the illumination value of the
lightreachingeachdisplaypixelofthe first lightmodulation
device based on the light adjustment information and the
distribution information of the illumination intensity. The
image information generation unit generates the second image
informationtobeset inthe first lightmodulationdevicebased
on the illumination value and the first image information.
Accordingly, it is possible to generate the second image
information to be set in the first light modulation device in
consideration ofthe illumination light fromthe illumination
unit. That is, it is possible to generate the pixel
information (pixel value) to be set in the display pixel.
[00101
[Application Example 31 In the image display apparatus
according tothe applicationexample, in the image information
generation unit, a value obtained by dividing a pixel value
of the first image information by the illumination value is
set as a pixel value of the second image information.
[00111
In the image display apparatus, the value obtained by
dividingthe first image informationby the illuminationvalue
is set to be the second image information. Accordingly, in
consideration of brightness control by the light adjustment
of the illumination unit, the brightness of the first image
information can be maintained to be substantially equal even
in the second image information.
[00121
[Application Example 41 In the image display apparatus
according to the application example, the feature amount of
the first image information in the light adjustment
informationdecisionunit is settoamaximumvalueofthepixel
valueof the first imageinformationin~heilluminationrange.
[00131
In the image display apparatus, the feature amount of
the first image information is assumed to be the maximum value
of the plxel value of the first image information in the
illumination range. Accordingly, it is possible to suppress
I
deterioration in the brightness of the illumination value by
which the display pixels of the first light modulation device
are illuminated, and thus it is possible to perform the light
adjustment control capable of reproducing substantially the
brightness of the input first image information.
[00141
[Application Example 51 An image display apparatus
according to this application example includes: a first light
modulation device that modulates light; an illumination unit
that includes a plurality of light adjustment elements and
emits the adjustedl~ghttothe first light modulation device;
and a light modulation control unit that controls the first
light modulation device and the illumination unit based on
first image information. The plurality of light adjustment
elements illuminate eachillumination range in the first light
modulation device. Each of the illumination ranges overlaps
with a part of the mutually adjacent illumination range. When
the first image information indicates a maximum gray scale in
one frame period or one sub-frame period as a gray scale of
at least a partial region of the region with which the
illuminationrangeoverlaps, the light modulation control unit
controls the illumination unit so that the light adjustment
elements illuminating the partial region commonly emit the
light with the maximumgray scale among the plurality of light
adjustment elements.
I
[0015]
In the image display apparatus, the plurality of light
adjustment elements illuminate each illumination range on the
first light modulation device and each illumination range
overlaps with parts of the mutually adjacent illumination
ranges. When the first image information indicates the
maximum gray scale in one frame period or one sub-frame period
as the gray scale of at least the partial region of the region
with which the illumination range overlaps, the light
modulation control unit controls the illumlnationunit sothat
the light adjustment elements illuminating the partial region
commonly emit the light with the maximum gray scale among the
plurality of light adjustment elements. Accordingly, it is
possible to illuminate the display pixels of the maximum gray
scale with the maximum gray scale.
[0016]
[ApplicationExample 61 Amethodof controlling an image
display apparatus according to this application example is a
method of controlling an image display apparatus including a
first light modulation device that includes a plurality of
display pixels and modulates light based on input first image
information, an illumination unit that includes a plurality
of light adjustment elements and emits adjusted light to the
first light modulation device, and an illumination
distribution storage unit that stores an illumination range
in which the light emitted from the light adjustment elements
illuminates the display pixels of the first light modulation
device. The method includes a light adjustment information
decision step of deciding light adjustment information to
control the light adjustment elements of the illuminationunit
based on a feature amount of the first image information
corresponding to the display pixels of the illumination range
stored in the illumination distribution storage unit.
[00171
Inthemethodof controllingthe imagedisplayapparatus,
the illumination unit can perform the light adjustment in
consideration of the feature amount of the first pixel
information corresponding to the illumination range of the
illumination light.
[Application Example 71 In the method of controlling an
image display apparatus according to the application example,
the illumination distribution storage unit further stores
distribution information of an illumination intensity with
which the light emitted from the light adjustment elements
illuminates the display pixels of the flrst light modulation
device. The method further includes: an illumination value
calculation step of calculating an illumination value of the
light arriving at each of the displaypixels of the first light
modulation device based on the light adjustment information
1
of the illumination unit and the distribution information of
the illumination intensity; and an image information
generation step of generating second image information to be
set in the first light modulation device based on the
illumination value calculated in the illumination value
calculation step and the first image information.
[00191
In themethodof controlling an image display apparatus,
it is possible to generate the second image information to be
set in the first light modulation device in consideration of
the illumination light from the illumination unit. That is,
it is posstble to generate the pixel information (pixel value)
to be set in the display pixels.
[00201
When the image display apparatus and the method of
controlling the image display apparatus described above are
constructed using a computer included in the image display
apparatus, the foregoing forms and application examples can
be configuredbyanaspectof aprogramrealizingthe functions
orarecordingmediumrecordingtheprogramsothatthecomputer
can read the program.
As the recording medium, various computer-readable
media such as a flexible disc, a hard disk device (HDD), a
compact disk read-only memory (CD-ROM), a digital versatile
disk (DVD), a BLU-RAY DISC (registered trademark), a
i
magneto-optical disc, a nonvolatile memory card, an internal
storage device (a semiconductor memory such as a random access
memory (RAM) or a read-only memory (ROM) ) of the image display
apparatus, or anexternal storage device (universal serial bus
(USB) memory or the like) of the image display apparatus can
be used
[Brief Description of Drawings]
[00211
[Fig. 11 Fig. 1 is a schematic configuration diagram
illustrating optical units of a projector according to an
embodiment.
[Fig. 21 Fig. 2 is a block diagram illustrating a
schematic configuration of the projector according to the
embodiment.
[Fig. 31 Fig. 3 is a perspective view illustrating
dispositionof light adjustment liquid crystal light valve and
display liquid crystal light valve.
[Fig. 41 Fig. 4 is a front view illustrating the light
adjustment liquid crystal light valve and the display liquid
crystal light valve, Fig. 4(a) is a front view for the light
adjustment liquid crystal light valve, and Fig. 4 (b) is a front
view for the display liquid crystal light valve.
[Fig. 51 Fig. 5 is a diagram illustrating an intensity
distribution in an illumination range of the display liquid
crystal light valves.
2
[Fig. 61 Fig. 6 is a flowchart illustrating a process
performed by a light valve control unit of the projector.
[Fig. 71 Fig. 7 is a perspective view illustrating an
LED array.
[Description of Embodiments]
[0022]
(Embodiment)
Hereinafter, as an embodiment of an image display
apparatus, a projector that displays an image by modulating
light emitted from a light source based on image information
(image signal) and projecting the modulated light to an
external screen or the like will be described with reference
to the drawings.
[00231
Fig. 1is a schematic configurationdiagramillustrating
optical units of the projector according to an embodiment.
As illustrated in Fig. 1, a projector 1 includes a light
sourcedevice 11, a first fly-eye lens 12a anda second fly-eye
lens 12bwhichare fly-eye lenses (uniformilluminationunits),
a polarization conversion device 13, dichroic mirrors (color
splitting units) 14a and 14b, reflection mirrors 15a, 15b, and
15c, light adjustment liquid crystal light valves 17R2, 17G2,
17B2 serving as a second light modulation device, display
liquid crystal light valves 17R1, 17G1, and 17B1 serving as
a first light modulation device, a cross dichroic prism 18,
i
and a projection lens (projection unit) 19.
LOO241
An illumination optical system according to the
embodiment is configured to include the light source device
11, the first fly-eye lens 12a and the second fly-eye lens 12b
(referred to as the fly-eye lenses 12a and 12b), and the
polarization conversion device 13. The light source device
11 is configured to include a light source lamp lla such as
a high-pressure mercury lamp and a reflector llb that reflect
light from the light source lamp lla. As uniform illumination
units that unify an illuminance distribution of light-source
light in the liquid crystal light valves 17R, 17G, 17B which
are illuminated regions, the first fly-eye lens 12a and the
second fly-eye lens 12b are installed sequentially from the
side o f t h e l i g h t s o u r c e d e v i c e 1 1 . Eachofthe fly-eye lenses
12a and 12b is configured to include a plurality of lenses and
functions as a uniform illumination unit unifying the
illuminance distribution of the light emitted from the light
source device 11 in the liquid crystal light valve which is
anilluminatedregion. Thelightemittedfromthelightsource
device 11 is emitted from the uniform illumination unit to the
polarization conversion device 13.
[00251
The polarization conversion device 13 is configured to
include a polarization beam splitter array (PBS array)
i
installed on the side of the uniform illumination unit and a
1/2wavelengthplatearrayinstalledonthe sideofthedichroic
mirror 14a. The polarization conversion device 13 is
installed between the uniform illumination unit and the
dichroic mirror 14a.
LO0261
A configuration of the rear stage of the light source
device 11 will be described along with an operation of each
constituent element. The dichroic mirror 14a for blue and
green llght reflection transmits red light LR of a light flux
from the light source device 11 and reflects blue light LB and
green light LG. The red light LR transmitted through the
dichrolcmirror 14a is reflectedbythe reflectionmirror 15c,
is incident on the red light adjustment liquid crystal light
valve 17R2 so that its intensity (light amount) is adjusted
herein, and is subsequently incident on the red light display
liquid crystal light valve 17R1. The red light adjustment
liquid crystal light valve 17R2 is disposed between the
r e f l e c t i o n m i r r o r 1 5 c d i s p o s e d o n a s i d e o f t h e d i c h r o i c m i r r o r
14a and the red light display liquid crystal light valve 17R1.
LOO271
On the other hand, of the color light reflected by the
dichroic mirror 14a, green light LG is reflected by the green
light reflectiondichroic mirror 14b, is incident on the green
light adjustment liquid crystal valve 17G2 so that its
6
intensity (light amount) is adjusted, and is subsequently
incident on the green light display liquid crystal light valve
17G1. The green light adjustment liquid crystal light valve
17G2 is disposed between the dichroic mirror 14b disposed on
a side of the dichroic mirror 14a and the green light display
liquid crystal light valve 17G1. On the other hand, the blue
light LB is transmitted through the dichroic mirror 14b, is
incident on the blue light adjustment liquid crystal light
valve 17B2 via a relay system R1 including a relay lens 16a,
I
a reflection mirror 15a, a relay lens 16b, a reflection mirror
15b, and a relay lens 16c, so that its intensity (light amount)
is adjusted, and is subsequently incident on the blue light
display liquid crystal light valve 17B1. The blue light
adjustment liquidcrystal light valve 17B2 is disposedbetween
the relay lens 16c disposed on a side of the dichroic mirror
14bandtheblue l i g h t d i s p l a y l i q u i d c r y s t a l l i g h t v a l v e 1 7 B 1 .
[0028l
In the embodiment, the light adjustment liquid crystal
lightvalves 17R2, 17G2, and1782 andthedisplayliquidcrystal
light valves 17R1, 17G1, and 17B1 described above are disposed
at a predetermined distance.
[00291
The foregoing light adjustment liquid crystal light
valves 17R2, 17G2, and 17B2 are schematically configured to
include aliquidcrystalpanel, i n w h i c h a l i q u i d c r y s t a l l a y e r
i
is interposed between one pair of glass substrates (light
transmissive substrates), light transmission electrodes are
formed on the surfaces of the one pair of glass substrate on
the sides of the liquid crystal layer, and alignment films are
formed on the surfaces of the light transmissive electrodes
on the liquid crystal layer, and polarization plates stacked
on both sides of the liquid crystal panel.
[00301
The red light adjustment liquid crystal light valve 17R2
canfreelychangetransmittance inarangeofthetransmittance
from a value close to 0% to 100% when the magnitude of a voltage
to be applied is changed at the time of reception of a driving
s i g n a l f r o m a l i g h t a d j u s t m e n t l i q u i d c r y s t a l d r i v i n g u n i t 1 1 0 b
to be described below and at the time of application of the
driving signal to the light transmissive electrodes. By
changing the transmittance in the range of the value close to
0% to 100% in this way, the intensity (light amount) of the
red light LR emitted from the red light adjustment liquid
crystal light valve 17R2 can be changed. The intensity (light
amount) of the red light LR is adjusted by the red light
adjustment liquid crystal light valve 17R2 by increasing the
intensity (light amount) of the red light LR in such a manner
that the transmittance is increased by lowering a voltage to
be applied according- to a video or the transmittance is
decreased by increasing the intensity (light amount) of the
red light LR or raising the voltage to be applied.
[003ll
The green light adjustment liquid crystal light valve
17G2 can freely change transmittance in a range of the
transmittance from a value close to 0% to 100% when the
magnitude of a voltage to be applied is changed at the time
of reception of a driving signal from the light adjustment
liquid crystal driving unit llOb to be described below and at
the time of application of the driving signal to the light
transmissiveelectrodes. Bychangingthetransmittanceinthe
rangeofthevalue close to O%tolOO%inthisway, the intensity
(light amount) of the green light LG emitted from the green
light adjustment liquidcrystal light valve 17G2 canbechanged.
The intensity (light amount) of the green light LG is adjusted
by the green light adjustment liquid crystal light valve 17G2.
lo0321
Thebluelightadjustmentliquidcrystallightvalve17B2
canfreelychangetransmittance inarangeofthetransmittance
fromavalue close to 0% to 100% whenthemagnitude of avoltage
to be applied is changed at the time of reception of a driving
signal from the light adjustment liquid crystal driving unit
110b to be described below and at the time of application of
the driving signal to the light transmissive electrodes. By
changing the transmittance in the range of the value close to
0% to 100% in this way, the intensity (light amount) of the
i
blue light LB emitted from the blue light adjustment liquid
crystal light valve 17B2 canbe changed. The intensity (light
amount) of the blue light LB is adjusted by the blue light
adjustment liquid crystal light valve 17B2.
LOO331
The three pieces of color lightmodulatedbythe display
liquid crystal light valves 17R1, 17G1, and 17B1 are incident
on the cross dichroicprism18. In the prism, four right-angle
prisms are joined and a dielectric multi-layer reflecting red
light and a dielectric multi-layer reflecting blue right are
formed in a cross form in the inner surface of the prism. The
three pieces of color lights are comblned by these dielectric
multi-layers sothat light indicating a color image is formed.
The combinedlight is projectedto aprojection surface SC such
as a screen by the projection lens 19 which is a projection
optical system, and thus an expanded image is displayed.
LOO341
The projector 1 includes an "illumination'unit" that
includes a plurality of light adjustment elements and can
independently control the light amount of light emitted from
each light adjustment element. In the embodiment, the
illumination unit includes the light source device 11 and the
light adjustment liquid crystal light valves 17R2, 17G2, and
17B2. The "light adjustment elements" included in the
illuminationunitcanadjustthelightamountoflightincident
i
on another optical element which is an illuminationtarget from
the light adjustment element. The illumination unit can also
independently control the light amount of light emitted from
each of the plurality of light adjustment elements. In the
embodiment, light adjustment pixels included in the light
adjustment liquid crystal light valves 17R2, 17G2, and 17B2
correspond to the light adjustment elements.
[00351
Next, the control of the projector 1 according to the
embodiment will be described.
In the case of a projector of the related art having no
llght adjustment function, input image information (vldeo
signal) is subjected to an appropriate correction process to
be supplied to a liquid crystal driving unit (liquid crystal
panel driver) without change. However, in the case of the
projector having a light adjustment function as in the
embodiment, it is necessary to control the intensity of each
color light based on image information.
[00361
Fig. 2 is a block diagram illustrating a schematic
configuration of the projector 1 according to the embodiment.
As illustrated in Fig. 2, the projector 1 includes an
image projection unit 10 serving as a display unit, a control
unit 20, an operation reception unit 21, an image information
inputting unit 31, an image processing unit 32, and a light
1
valve control unit 40.
LO0371
The image projection unit 10 is configured to include
the light source device 11, the three dlsplay liquid crystal
light valves 17R1, 17G1, and 17B1, the three light adjustment
liquid crystal light valves 17R2, 17G2, and 17B2, the
projection lens 19 serving as a projection system, a display
llquid crystal driving unit 110a, and the light adjustment
llquid crystal driving unit 110b. The display liquid crystal
light valves 17R1, 17G1, and 17B1 and the light adjustment
liquid crystal light valves 17R2, 17G2, and 17B2 are
collectively referred to as a liquid crystal light valve unit
17.
[0038]
In the image projection unit 10, a light amount of light
emitted fromthelight source devicellis adjustedbythellght
adjustment liquid crystal light valves 17R2, 17G2, 17B2, the
light is modulatedto image light by the display liquid crystal
light valves 17R1, 17G1, and 17B1, and the image light is
projected from the projection lens 19 to be displayed as an
image on the projection surface SC.
[00391
The light emitted from the light source device 11 is
converted into light with a substantially uniform luminance
distribution by an integrator optical system such as the
fly-eye lenses 12a and 12b, the light is split into color light
components of red (R), green ( G ) , and blue (B) which are the
three primary colors of light by the color splitting optical
system such as the dichroic mirrors 14a and 14b, and
subsequently the split color components are lncident on the
display liquid crystal light valves 17R1, 17G1, and 17B1 and
the light adjustment liquid crystal light valves 17R2, 17G2,
17B2.
[00401
The display liquid crystal light valves 17R1, 17G1, and
1 7 B l a n d t h e l i g h t a d j u s t m e n t l i q u i d crystal light valves 17R2,
17G2, 17B2 are configured to include a liquid crystal panel
inwhichliquidcrystal is sealedbetweenapair oftransparent
substrates. Each of the display liquid crystal light valves
17R1, 17G1, and 17B1 and the light adjustment liquid crystal
light valves 17R2, 17G2, 17B2 has a rectangular pixel region
in which a plurality of display pixels and a plurality of light
adjustment pixels (light adjustment elements) are arrayed in
a matrix form so that a driving voltage can be applied to the
liquid crystal for each pixel.
[00411
When the light adjustment liquid crystal driving unit
llOb applies a driving voltage to each light adjustment pixel
according to a light adjustment pixel value (light adjustment
amount), each light adjustment pixel is set to light
i
transmittance according to the light adjustment pixel value.
Therefore, the light emitted from the light source device 11
i s t r a n s m i t t e d t h r o u g h t h e p i x e l r e g i o n o f t h e l i g h t a d j u s t m e n t
liquid crystal light valves 17R2, 17G2, 17B2 so that the light
amountisadjustedandis output as light accordingtothe light
adjustment amount. The light output fromthelight adjustment
liquid crystal light valves 17R2, 17G2, 17B2 respectively
illuminatesthe display liquid crystal light valves 17R1, 17G1,
and 17B1.
[00421
WhenthedisplayliquidcrystaldrivingunitllOaapplies
a driving voltage according to image information to each
displaypixel, eachdisplaypixelis set to light transmittance
according to the image information. Therefore, the light
emitted from the light adjustment liquid crystal light valves
17R2, 17G2, 17B2 is transmitted through the pixel region of
the display liquid crystal light valves 17R1, 17G1, and 17B1
to be modulated so that image light according to the image
information is formed for each piece of color light. The
formed image light of the respective colors is combined for
each pixel by a color combination optical system (not
illustrated in Fig. 2 ) so that color image light is formed,
and subsequently the image light is expanded and projected by
the projection lens 19.
LO0431
The control unit 20 includes a central processing unit
( C P U ) , a RAM used to temporarily store various kinds of data
or the like, and a nonvolatile ROM and generally controls an
operation of the projector 1 by causing the CPU to operate
according to a control program stored in the ROM. That is,
the control unit 20 functions as a computer.
[00441
The operation reception unit 21 Includes a plurality of
operation keys so that a user gives various instructions to
the projector 1. As the operation keys included in the
operation reception unit 21 according to the embodiment, for
example, there are a power key used to turn on or off power,
an input switch key used to switch an input video signal, menu
keys usedto display a menu image forvarious kinds of setting,
direction keys used to select an item from the menu image, and
a decision key used to confirm a selected item.
LO0451
When the user operates any of various operation keys of
the operation reception unit 21, the operation reception unit
21 receives the operation and outputs a control signal
corresponding tothe operatedoperationkey tothe control unit
20. Then, when the control signal is input from the operation
receptionunit21, the controlunit2Operforms aprocessbased
on the input control signal to control an operation of the
projector 1. A remote controller (not illustrated) capable
of performing a remote operation may be configured to be used
as an input operation unit instead of the operation reception
unit 21oralongwiththe o p e r a t i o n r e c e p t i o n u n i t 2 1 . Inthis
case, the remote controller transmits anoperation signal such
as an infrared ray according to operation content of the user,
and a remote control signal reception unit (not illustrated)
receives the operation signal and delivers the operation
signal to the control unit 20.
LOO461
The image information inputting unit 31 includes a
plurality of input terminals, and image information with
various formats is input from an external image supply device
(not illustrated) such as a video reproduction device or a
personal computer to the input terminals. The image
information inputting unit 31 selects image informationbased
on an instruction from the control unit 20 and outputs the
selected image information to the image processing unit 32.
The image information corresponds to first image information.
LOO471
The image processing unit 32 converts the image
information input from the image information inputting unit
31 into image information indicating a gray scale of each
displayplxel. Further, basedonaninstructionofthecontrol
unit 20, the image processingunit 32 performs an imagequality
adjustment process on the converted image information to
adjust the image quality such as brightness, contrast,
sharpness, or hue. The image processing unlt 32 can also
superimpose an on-screen display (OSD) image such as a menu
image on an input image. Then, the image processing unit 32
outputs the processed image information to a light adjustment
information decision unit 42 and an image information
generation unit 44 of the light valve control unit 40.
[00481
The light valve control unit 40 is configuredto Include
an illumination distribution storage unit 41, the light
adjustmentinformationdecisionunit42, an llluminationvalue
calculationunit43, the image informationgenerationunit44.
The light valve control unit 40 corresponds to a light
modulation control unit.
[00491
The illumination distribution storage unit 41 is
configuredto include a nonvolatile memory. The illumination
distribution storage unit 41 stores an illumination range and
an intensity distribution in which the light emitted from the
light adjustment pixels ofthe light adjustment liquidcrystal
light valves 17R2, 17G2, 17B2 respectively illuminates the
display liquid crystal light valves 17R1, 17G1, and 17B1. A
storage form may be a lookup table (LUT) or may be used as a
function. Here, the intensity distribution corresponds to
distribution information of the illumination intensity.
2
[00501
The illumination range and the intensity distribution
are decided by an installation relation between the light
adjustment liquid crystal light valve and the display liquid
crystal light valve. Information regarding the illumination
range and the intensity distribution may be stored for each
piece of color light by an installation relation between the
light adjustment liquid crystal light valve and the display
liquid crystal light valve. When the installation relation
!
of each piece of color light is the same, the information may
be stored as one kind of relation.
[00511
Here, the illumination range and the intensity
distribution will be described.
Fig. 3 is a perspective view illustrating disposition
of light adjustment l i q u i d c r y s t a l l i g h t v a l v e 1 7 R 2 anddisplay
liquid crystal light valve 17R1.
Fig. 4 is a frontviewillustratingthe light adjustment
liquid crystal light valve 17R2 and the display liquid crystal
light valve 17R1, Fig. 4 ( a ) is a front view for the light
adjustment liquid crystal light valve 17R2, and Fig. 4 (b) is
a front view for the display liquid crystal light valve 17R1.
LOO521
In Figs. 3 and 4, the light adjustment liquid crystal
light valve 17R2 and the display liquid crystal light valve
(
17R1 are illustrated. Although not illustrated, the light
adjustment liquid crystal light valves 17G2 and 17B2 and the
display liquidcrystal light valves 17G1 and17B1 have the same
configuration. Here, the description will be made using the
light adjustment liquid crystal light valve 17R2 and the
display liquid crystal light valve 17R1.
[00531
In the embodiment, to facilitate the description, the
light adjustment liquid crystal light valve 17R2 has a
configuration of the llght adjustment pixels of 3 rows X 4
columns. The coordinates of each light adjustment pixel are
expressed as (m, n). The display liquid crystal light valve
17R1 has a configuration of the display pixels of 12 rows X
16 columns. The coordinates of each display plxel are
expressed as (i, j) . In the embodiment, one light adjustment
pixel of the light adjustment liquid crystal light valve 17R2
is assumed to have a size corresponding to the display pixels
of 4 x 4 of the display liquid crystal light valve 17R1.
100541
Here, as illustrated in Figs. 3 and 4, one light
adjustment pixel (in Fig. 3, four corners are indicated by
diagonal lines of A2, B2, C2, and D2) of the light adjustment
l i q u i d c r y s t a l l i g h t v a l v e 1 7 R 2 i s a s s u m e d t o a l i g h t a d j u s t m e n t
pixel P2 of interest (2, 3). Light passing through the light
adjustment pixel of interest reaches not only the display
I
pixels of 4 x 4 (a region of which four corners are Al, B1,
C1, and D l ) of the display liquid crystal light valve 1 7 R 1
corresponding to the light adjustment pixel of interest but
also the periphery of these display pixels. That is, the
peripheral display pixels are also illuminated by the
expansion of the light passing through the light adjustment
pixels of interest.
[00551
In the embodiment, the li,ght passing through the light
1
adjustment pixel of interest P2 (2, 3) of the light adjustment
liquid crystal light valve 17R2 reaches a region indicated by
the diagonal lines of the display liquid crystal light valve
17R1. The region indicated by the diagonal lines is assumed
to be an illumination range SA. The illumination range SA is
decidedbya disposition relationbetween the light adjustment
liquid crystal light valve 17R2 and the display liquid crystal
light valve 17R1, is measured in advance when a product is
developed, and is stored in the illumination distribution
storage unit 41.
LO0561
Fig. 5 is a diagram illustrating an intensity
distribution in the illuminationrange SAof thedisplayliquld
crystal light valves 17R1, 17G1, and 17B1.
As illustrated in Fig. 5, an illumination intensity S
is written for each of the display pixels of the illumination r
range SA. The illumination intensity S has a higher value as
the illumination intensity S is closer to its center and has
a lower value as the illumination intensity S is closer to its
periphery. The illumination intensity S is decided by the
disposition relation between the light adjustment liquid
crystal light valve 17R2 and the display liquid crystal light
valve17R1, ismeasuredinadvancewhenaproductis developed,
and is stored along with the illumination range SA in the
illumination distribution storage unit 41. Here, the
illumination intensity S of each display pixel is expressed
by a value equal to or greater than "0" and equal to or less
than I' 1 . "
100571
Referring back to Fig. 2, the light adjustment
informationdecisionunit42 decides alight adjustment amount
of each of the light adjustment pixels of the light adjustment
liquidcrystal light valves 17R2, 17G2, and17B2 foreachlight
adjustment pixelbasedon the feature amount ofthe first image
information corresponding to the display pixels of the
illumination range SA of the display liquid crystal light
valves 17R1, 17G1, and 17Bl. In the embodiment, the feature
amount is assumed to be the maximum value. For example, for
the light adjustment pixel P2 (2, 3) of the light adjustment
liquid crystal light valve 17R2, the maximumvalue of the first
image information corresponding to the illumination range SA
1
is assumed to be a light adjustment amount (gray scale (pixel
value) ) .
[00581
The projector 1 performs various kinds of image
processing on the first image information in some cases. At
this time, the light adjustment information decision unit 42
may decide the feature amount based on the first image
information after the various kinds of image processing is
performed. For example, whenthenumber of pixels of the first
image information does not accord with the number of pixels
ofthedisplay liquidcrystal light valves 17R1, 17G1, and17B1,
the projector 1 performs a resizing process (resolution
conversion process) on the first image information sothat the
both numbers of pixels accord with each other. In this case,
image information after the resizing process is performed may
be defined as the first image information. At this time, the
light adjustment information decision unit 42 may decide the
feature amount based on the image information after the
resizing process is performed.
[00591
Here, when In-Pl (i, j) is a gray scale (pixel value)
ofthe firstimageinformationcorrespondingtoadisplaypixel
(i, j) included in an illumination range SA (m, n) for a light
adjustment pixel (m, n) , the following formula (1) is assumed
to be established.
i
0 In-P1 i , j < 1, (i, j) E SA (m, n) . . . (1)
When F (m, n) is the maximum value (feature amount) of
the first image information corresponding to the light
adjustment pixel (m, n) , the following formula (2) is
established.
F (m, n) = max (1n-P1 (i, j ) ) . . . (2)
[ 0 0 6 1 ]
As in the following formula (3), the maximum value
(feature amount) of the first image information corresponding
to the light adjustment pixel (m, n) is assumed to be a light
adjustment amount (pixel value) A (m, n) of the light adjustment
pixel (m, n)
A (m, n) = F (m, n) . . . (3)
[00621
The illumination value calculation unit 43 calculates
an illuminationvalue ofthelightreachingeachofthedisplay
pixels of the display liquid crystal light valve 17R1 based
on the light adjustment amounts (pixel values) of the light
adjustment pixels of the light adjustment liquid crystal light
valves 17R2, 17G2, and 17B2 and the distribution information
of the illumination intensity S in the display liquid crystal
light valves 17R1, 17G1, and 17Bl.
LO0631
First, among all of the light adjustment plxels of the
light adjustment liquid crystal light valves 17R2, 17G2, and
17B2, the illurninationvalue calculation unit 43 extracts the
pixels for which the illumination reaches the display pixels
of interest of the display liquid crystal light valves 17R1,
17G1, and 17B1. Specifically, for example, for each of the
light adjustment pixels of the light adjustment liquid crystal
light valve 17R2, it is determined whether the display ~ixkl
of interest is included in the illumination range SA in which
the light passing through each light adjustment pixel reaches
the display liquid crystal light valve 17R1. When the dlsplay
pixel of interest is included, the light adjustment pixels are
extracted. Intheembodiment, when (i, j) = (6, 11) isadisplay
plxel of interest, nine light adjustment pixels P2 (1, 2), P2
(1, 31, P2 (1, 4 ) , P2 (2, 2), P2 (2, 3), P2 (2, 41, P2 (3, 21,
P2 (3, 3), and P2 (3, 4) of the light adjustment liquid crystal
llght valve 17R2 are extracted.
LO0641
Next, the illumination value calculation unit 43
calculates brightness for illumination of the display pixel
of interest of the display liquid crystal light valve 17R1 in
accordance wlth the light adjustment pixels extracted on the
light adjustment liquid crystal light valve 17R2. Here, in
accordance with the light adjustment pixels of the light
adjustment liquidcrystal light valve 17R2, thebrightness for
illumination of the display liquid crystal light valve 17R1
i
can be calculated by multiplying the light adjustment amount
A (m, n) of each light adjustment pixel by the distribution
of the illumination intensity S.
LO0651
WhenL (1, j) is brightness for illuminationof adisplay
pixel of interest (1, j) of the display liquid crystal light
valve 17R1, L (i, j) can be calculated by a total sum of the
llght reaching the display pixel of interest from each of the
nine light adjustment pixels extracted from the light
adjustment liquid crystal light valve 17R2. Here, an
illuminationintensitys (i, j, m, n) indicates an illumination
intensity corresponding to a positional relation between a
lightadjustmentpixelP2 (m, n) andadisplaypixel of interest
P1 (i, j) of the display liquid crystal light valve 17R1. The
brightness L (i, j) for illumination of the display pixel of
interest (i, j) is expressed in the following formula ( 4 ) .
L (i, j) =CA (m, n) X S i , j, m, n . . . (4)
Here, OSL (i, j) <1is assumedtobe satisfied. Further
m, n E SB (i, j) is assumed to be satisfied.
SB (i, , j ) is a set of light adjustment pixels (m, n)
illuminating the display pixel of interest (i, j ) , and C
(sigma) of all the light adjustment pixels (m, n) included in
SB (i, j) is calculated. In the embodiment, (m, n) indicates
the extracted nine light adjustment pixels P2 (1, 2), P2 (1,
3), P2 (1, 4), P2 ( 2 , 21, P2 (2, 3), P2 (2, 4), P2 (3, 2), p2
i
(3, 3), andP2 (3, 4) illuminatingthedisplaypixel of interest
(i, j) = (6, 11).
LO0661
The image information generation unit 44 calculates the
pixel signal of the display pixel of interest, that is, the
second image information, basedon the first image information
input from the image processing unit 32 and the illumination
value L (i, j) of the light reaching the display pixel of
interest of the display liquid crystal light valve 17R1
(
calculated by the illumination value calculation unit 43.
Here, the image informationgenerationunit44 assumes avalue
obtainedbydividingthe first image information corresponding
to the display pixel of interest by the brightness for
illumination of the display pixel of interest to be a pixel
signal of the display pixel of interest (second image
information (pixel value)) Out - PI (i, j). Then, Out - P1 (i,
j) is expressed in the following formula (5).
Out-P l (i, j) = I n-P l i , L i , j . . . ( 5 )
Here, 0 < Out-PI (i, j) < 1 is assumed to be satisfied.
LO0671
In the embodiment, as described above, the pixel value
or the value of the brightness or the like is expressed as a
gray scale equal to or greater than "0" and equal to or less
than "1. 'I
LOO681
The light adjustment liquid crystal driving unit llOb
drives the light adjustment liquid crystal light valves 17R2,
17G2, and 17B2 according to the light adjustment amount A (m,
n) input from the light adjustment information decision unit
42. The display liquid crystal driving unit llOa drives the
display liquid crystal light valves 17R1, 17G1, and 17B1
according to the second image information Out-PI (i, j) input
from the image information generation unit 44. Accordingly,
the light emitted from the light source device 11 is adjusted
b y t h e l i g h t a d j u s t m e n t l i q u i d c r y s t a l l i g h t v a l v e s 1 7 R 2 , 17G2,
and 17B2, the adjusted light is modulated into image light
accordingtothe secondimage informationbythedisplay Liquid
crystal light valves 17R1, 17G1, and 17B1, and the image light
is projected from the projection lens 19.
[00691
Next, aprocessperformedineachframeoreachsub-frame
by the light valve control unit 40 of the projector 1 will be
described with reference to a flowchart.
Fig. 6 is a flowchart illustrating a process performed
by the light valve control unit 40 of the projector 1.
[00701
The light valve control unit 40 repeats processes from
step SlOl to step S106 on each of the light adjustment pixels
ofthe light adjustment liquidcrystal light valves 17R2, 17G2,
and 17B2 (loop Lol) (step S101).
!
[00711
First, the light adjustment information decision unit
42 calculates the maximum value (feature amount) F (m, n) of
the first image informationcorresponding tothe displaypixel
on the illumination range SA of the light adjustment pixel of
interest (step 5102). Then, the light adjustment information
decisionunit42 assumesthemaximumvalue tobethepixelvalue
(light adjustment amount) A (m, n) ofthe light adjustment pixel
of interest the light adjustment liquid crystal light valves
17R2, 17G2, and 17B2 (step S103). Then, the process returns
tostepSlOlandtheprocessesarerepeatedsettingasubsequent
light adjustment pixel as the light adjustment pixel of
interest (step 5104) .
[00721
In this way, the pixel value (light adjustment amount)
A (m, n) is decided for all of the light adjustment pixels of
the light adjustment liquid crystal light valves 17R2, 17G2,
and 17B2. The pixel value (light adjustment amount)
corresponds to light adjustment information.
LOO731
Next, the light valve control unit 40 repeats processes
from step S105 to step S109 on each of the display pixels of
the display liquid crystal light valves 17R1, 17G1, and 17B1
(loop Lo2) (step S105) .
LO0741
i
First, the illumination value calculation unit 43
extracts the light adjustment pixels for which the
illumination reaches the display pixel of interest (i, j) of
the display liquid crystal light valves from all of the light
adjustment pixels of the light adjustment liquid crystal light
valves 17R2, 17G2, and 17B2 (step S106). Then, the
illumination value L (i, j) with which the dlsplay pixel of
interest of the display liquidcrystal light valves 17R1, 17G1,
and 17Blis calculatedinaccordancewitheachof the extracted
I
light adjustment pixels and the illumination intensity S (i,
j, m, n) (step S107) .
LOO751
The image information generatlon unit 44 calculates the
pixel value (second image information) Out-P1 (i, j ) to be set
in the displaypixel of interest of the dlsplayliquid crystal
light valves 17R1, 17G1, and 17Bl by dividing the pixel value
corresponding tothe first image informationby the calculated
illumination value (step S108) . Then, the process returns tc
step 5105 and the processes are repeated setting a subsequent
display pixel as the display pixel of interest (step S109)
When the processes end for ali of the display pixels,
the light valve control unit 40 ends the processes performed
ineach frameoreachsub-frame. The processes are repeatedly
performed in a subsequent frame or sub-frame. Each
I
illumination pixel value (light adjustment amount) A (m, n)
and17B2 generatedintheprocesses andeachdisplaypixelvalue
(second image information) Out - P1 (i, j) of the display liquid
crystal light valves 17R1, 17G1, and 17B1 are output to the
light adjustment liquid crystal driving unit 110b and the
displayliquidcrystaldrivingunitllOa, respectively. Then,
the light adjustment liquid crystal light valves 17R2, 17G2,
and17B2 andthedisplay liquidcrystal lightvalves 17R1, 17G1,
and 17B1 are driven according to the pixel values.
According to the above-described embodiments, the
following advantages can be obtained
(1) The projector 1 includes the display liquid crystal
light valves 17R1, 17G1, and 17B1 including the display pixels
and the light adjustment liquidcrystal light valves 17R2, 17G2,
and17B2 includingthe light adjustmentpixels. The projector
1 performs the light adjustments setting the maximum value of
the pixel values of the first image information corresponding
to the displaypixels of the illumination range on the display
liquid crystal light valves 17R1, 17G1, and 17Bl illuminated
by the light passing through the light adjustment pixels as
the pixel value (that is, the light adjustment amount (light
adjustment information) ) A (m, n) of the light adjustment pixel
ofthe light adjustment liquidcrystal light valves 17R2, 17G2,
and 17B2. Accordingly, based on the pixel value of the first
image information correspondingto the illumination range of
the illumination light fromeachofthelightadjustmentpixels,
each of the light adjustment pixels of the light adjustment
liquid crystal light valves 17R2, 17G2, and 17B2 can perform
appropriate light adjustment. For example, when a bright
pixel is present in the first image information, the light
adjustment is performed to reproduce the brightness, and thus
the advantageous effect can be obtained.
LO0781
(2) The projector 1 calculates the illumination value
L (i, j) of the light reaching each of the display pixels of
the display liquid crystal light valves 17R1, L7G1, and 17B1
based on the light adjustment pixel value (light adjustment
amount) A (m, n) and the distribution information of the
illumination intensity S (i, j, m, n) . The second image
information Out-P1 (i, 9 ) to be set in the display liquid
crystal light valves 17R1, 17G1, and 17Bl is generated by
dividing the first image information In-P1 (i, j ) by the
illuminationvalueL (i, ji ofeachdisplaypixel. Accordingly,
the second image information Out - PI (i, j) can be generated
in consideration of the illumination light from the light
adjustment liquld crystal light valves 17R2, 17G2, and 17B2.
That is, the gray scale expression substantially faithful to
the input first image information In PI (i, j ) can be realized
i
-
in consideration of the illumination light, and thus the
advantageous effect can be obtained.
[00791
(3) The projector 1 includes the display liquid crystal
light valves 17R1, 17G1, and 17B1 and the light adjustment
liquld crystal light valves 17R2, 17G2, and 17B2. The
brightness of light incident on the display liquid crystal
light valves 17R1, 17G1, and 17B1 can be controlled in
accordance with the light adjustment llquid crystal light
valves 17R2, 17G2, and17B2. Therefore, since the input first
image information (video signal) can be reproduced with high
contrast, the advantageous effect can be obtained.
[00801
(4) The projector 1 stores the illumination range SA and
theilluminationintensityS inwhichthe light passingthrough
the light adjustment pixels of the light adjustment liquid
crystal light valves 17R2, 17G2, and 17B2 illuminates the
displaypixels ofthe display liquidcrystal light valves 17R1,
17G1, and 17B1 in the illumination distribution storage unit
41. The illumination range SA and the illumination intensity
S are decided by the disposition relation between the light
adjustment liquid crystal light valves 17R2, 17G2, and 17B2
and the corresponding display liquid crystal light valves 17R1,
17G1, and 17B1, are measured in advance when a product is
developed, and are stored in the illumination distribution
i
storage unit 41. The illumination range SA and the
illumination intensity S are considered to be changed by an
apparatus configuration of a product (distances between the
light adjustment liquid crystal light valves 17R2, 17G2, and
17B2 and the display liquid crystal light valves 17R1, 17G1,
and17B1, optical elementsbetweenthe light adjustment liquid
crystallightvalves17R2, 17G2, and17B2 andthedisplay liquid
crystal light valves 17R1, 17G1, and17B1, the characteristics
of an incident angle of illumination light, and the like) . In f
the embodiment, since the change in the apparatus
configuration of the product can be handled by rewriting the
illumination distribution storage unit 41, the advantageous
effect can be obtained.
[00811
As described above, the light passing through the light
adjustment pixels spreads and reaches the display liquid
crystal light valves 17R1, 17G1, and 17B1. Therefore, the
illumination ranges SA partially overlap with the mutually
adjacent illumination ranges SA. That is, a region (or the
display pixels included in the region) in which the
illumination ranges SA partially overlap with each other is
illuminated commonly in accordance with at least two mutually
adjacent illuminationpixels. Insettinginwhichthemaximum
luminance (maximum gray scale) of the display pixels included
in the illumination range SA is adopted as the illumination
i
amount A (m, n) of the light adjustment pixel (m, n), when the
gray scale of at least a partial region in the region in which
the illumination ranges SA partially overlap with each other
is designatedasthemaximumgrayscalewithinone frame period
or within one sub-frame period (that is, one vertical period)
of the first image signal or the light valve in accordance with
the first image signal, all of the light adjustment amounts
A (m, n) of at least two light adjustment pixels (m, n) commonly
illuminating the region are set to the maximum gray scale in
the light adjustment pixels included in the light adjustment
liquid crystal light valves 17R2, 17G2, and 17B2 by formula
(2) and formula (3) above.
[ 0 0 8 2 ]
Here, the partial region may include one display pixel
or may include a plurality of display pixels. When the gray
scale of the partial region is the highest within the period,
itispreferabletodeterminethatthegrayscaleofthepartial
region is not noise to be described in Modification Example
1 below. For example, according to a difference between the
gray scale of the partial region and a gray scale of its
peripheral region or a difference between the gray scale of
the partial region and the gray scale of the peripheral region
in previous and subsequent frames (or one frame may be used),
it is preferable to determine whether the light adjustment
amounts A (m, n) of the light adjustment pixels commonly
f
illuminating the partial region is set to the maximum gray
scale.
[00831
The invention is not limited to the above-described
embodiment, but canbe further modified or improve dinvarious
forms. Modification examples will be described below.
[00841
(Modification Example 1) In the foregoing embodiment,
the feature amount used by the light adjustment information
decision unit 42 is set to the maximum value of the first image
information, butmaynotnecessarilybethemaximumvalue. For
example, a bright pixel in a dark screen region is contained
as noise in some cases. In this case, when the feature amount
is set tothemaximumvalue, ablack color floats in some cases.
For this reason, the feature amount may not necessarilybe set
to the maximum values. For example, the feature amount may
be set to 90% of the maximum value of the pixel value or may
be set to an average value. The feature amount may be set to
a pixel value ranked to be lower from the maximum value. For
example, the third pixel value may be used. A histogram
detection unit (not illustrated) that extracts a histogram
(emergence frequency distribution) of each color of the red
light LR, the green light LG, and the blue light LB from the
first image information (video signal) may be provided so that
the feature amount is decided based on the frequency
distribution.
[00851
(Modification Example 2) The projector 1 may include a
noise reduction circuit (not illustrated). By performing
noise reduction on the first image information input to the
light valve control unit40 to removenoise, the feature amount
used by the light adjustment information decision unit 42 may
be set to the maximum value of the first image information.
[00861
(Modification Example 3) In the foregoing embodiment,
theilluminationunit is c o n f i g u r e d t o i n c l u d e t h e l i g h t s o u r c e
device 11 and the light adjustment liquid crystal light valves
17R2, 17G2, and17B2, butthe lightsourcedeviceandthe liquid
crystal light valves may be integrated as in, for example, a
light-emitting diode (LED) array. That is, the illumination
unit may be an LED array.
Fig. 7 is a perspective view illustrating an LED array.
As illustrated in Fig. 7, an LED array 50 is formed such that
a plurality of light-emitting units (LEDs) L1 are arrayed in
a matrix form. The LED array 50 may be configured to be
installed insteadofthe light adjustment liquidcrystal light
valves 17R2, 17G2, and 17B2 of the projector 1. When the image
display apparatus is a flat panel display (FPD) or the like,
the LED array 50 may be configured to be installed as an
illuminationunit ontherear surface sideofthe liquidcrystal
(
panel or the like of the FPD. In this case, each of the
plurality of light-emitting units L1 included in the LED array
50 corresponds to a light adjustment element.
LO0871
(Modification Example 4) In the foregoing embodiment,
the light adjustment liquid crystal light valves 17R2, 17G2,
and17B2 andthedisplayliquidcrystallightvalves17R1, 17G1,
and 17Blare installedatthepredetermineddistance. However,
the intervals (distances) between the light adjustment liquid
crystallightvalves17R2, 17G2, and17B2 andthedisplay liquid
crystal light valves 17R1, 17G1, and 17B1 for red light, green
light, and blue light may not be identical. Further, optical
elements (relay lenses) or the like may be included between
the light adjustment liquid crystal light valves 17R2, 17G2,
and17B2 a n d t h e d i s p l a y l ~ q u i d c r y s t a l l i g h t v a l v e s 1 7 R 11, 7G1,
and 17B1.
I00881
(Modification Example 5) In the foregoing embodiment,
the illumination distribution storage unit 41 stores the
illumination range SA and the illumination intensity S
(intensity distribution) in advance. However, the
illumination range SA and the illumination intensity S may be
written or rewritten by the control unit 20. In this case,
the projector 1 includes a communication unit (not
illustrated) to receive information regarding the
d
illumination range SA and the illumination intensity S from
an external apparatus and notify the control unit 20 of the
information.
[00891
(Modification Example 6) In the foregoing embodiment,
the illumination distribution storage unit 41 stores one type
of information regarding the illumination range SA and the
intensity distribution or stores the information for each
piece of color light. However, a plurality of pieces of
information may be stored to be switched according to the
positions of the light adjustment pixels of the light
adjustment liquid crystal light valves 17R2, 17G2, and 17B2.
[00901
(Modification Example 7) In the foregoing embodiment,
the projector 1 has been described as an example. However,
the image display apparatus is not limited to the projector.
For example, the invention can also be applied to a rear
projector in which a transmission type screen is integrated,
a liquid crystal display, a plasma display, an organic
electro-luminescence (EL) display, or the like.
[00911
(Modification Example 8) In the foregoing embodiment,
the light source device 11 is configured to include the
dischargetypelightsourcelamplla, butnotonlyasolid-state
light source such as a laser or an LED light source but also
i
any of the other light sources may also be used.
[00921
(Modification Example 9) In the foregoing embodiment,
t h e p r o j e c t o r l u s e s t h e t r a n s m i s s i o n t y p e l i q u i d c r y s t a l l i g h t
valves17R1, 17G1, and17B1asthefirstlightmodulationdevice,
but reflection light modulation devices such as reflection
type liquid crystal light valves can also be used. A micro
mirror array device or the like that modulates light emitted
from a light source by controlling an emission direction of
incident light for each mirror serving as pixels can also be
used as the light modulation device. Similarly, the
transmissiontype light adjustment liquidcrystal light valves
17R2, 17G2, and 17B2 are used as the llght modulation devices
included in the illumination unit, but reflection light
modulation devices such as reflection type liquid crystal
light valves can also be used. A micro mirror array device
or the like that modulates light emitted from a light source
b y c o n t r o l l ~ n g a n e m i s s i o n d i r e c t i o n o f i n c i d e n t l i g h t f o r e a c h
mirror serving as pixels can also be used as the light
modulation device.
[Reference Sign List]
[00931
1 projector
10 image projection unit
11 light source device
lla light source lamp
llb reflector
12a first fly-eye lens
12b second fly-eye lens
13 polarization conversion device
14a dichroic mlrror
14b dichroic mirror
15a, 15b, 15c reflection mirror
16a, 16b, 16c relay lens
17 liquid crystal light valve unit
17R1, 17G1, 17B1 display liquid crystal light valve
17R2, 17G2, 17B2 light adlustment liquid crystal light
valve
18 cross dichroic prism
19 projection lens
20 control unit
21 operation reception unit
31 image information input unit
32 image processing unit
40 light valve control unit
41 illumination dlstrlbution storage unit
42 light adjustment information decision unit
43 illumination value calculation unit
44 image information generation unit
50 LED array
llOa display liquid crystal driving unit
110b light adjustment liquid crystal driving unit
SC projection surface
[Designation of Document] Claims
[Claim 11
An image display apparatus comprising:
afirstlightmodulationdevicethatincludes aplurality
ofdisplaypixelsandmodulateslightbasedoninputfirstimage
information;
an illumination unit that includes a plurality of light
adjustment elements andemits adjustedlighttothe first light
1,
modulation device;
an illumination distribution storage unit that stores
an illumination range inwhich the light emitted fromthe light
adjustment elements illuminates the display pixels of the
first light modulation device; and
a light adjustment information decision unit that
decides light adjustment information to control the light
adjustment elements ofthe illuminationunit basedona feature
amount of the first image information corresponding to the
1
display pixels of the illumination range stored in the
illumination distribution storage unit.
[Claim 21
The image display apparatus according to claim 1,
wherein the illumination distribution storage unit
further stores distribution information of an illumination
intensity with which the light emitted from the light
adjustment elements illuminates the display pixels of the
first light modulation device, and
wherein the image display apparatus further comprises:
an illumination value calculation unit that calculates
an illumination value of the light arriving at each of the
display pixels of the first light modulation device based on
the light adjustment information of the illumination unit and
the distribution information of the illumination intensity;
and
i
an image information generation unit that generates
s e c o n d i m a g e i n f o r m a t i o n t o b e s e t i ~ ~ t h e f i r s t l i g h t m o d u l a t i o n
device based on the illumination value calculated by the
illumination value calculation unit and the first image
information.
[Claim 31
The image display apparatus according to claim 2,
whereininthe image informationgenerationunit, avalue
obtained by dividing a pixel value of the first image
information by the illumination value is set as a pixel value
of the second image information.
[Claim 41
The image.display apparatus according to any one of
claims 1 to 3,
wherein the featureamount ofthe first imageinformation
in the light adjustment information decision unit is set to
a maximum value of the pixel value of the first image
information in the illumination range.
[Claim 51
An image display apparatus comprising:
a first light modulation device that modulates light;
an illumination unit that includes a plurality of light
adjustment elements and emits the adjusted light to the first
light modulation device; and
a light modulation control unit that controls the first
light modulation device and the illumination unit based on
first image information,
wherein the plurality of light adjustment elements
illuminate each illumination range in the first light
modulation device,
wherein each of the illumination ranges overlaps with
a part of the mutually adjacent illumination range, and
wherein when the first image information indicates a
maximum gray scale in one frame period or one sub-frame period
I
as a gray scale of at least a partial region of the region with
which the illumination range overlaps, the light modulation
control unit controls the illumination unit so that the light
adjustment elements illuminating the partial region commonly
emit the light with the maximum gray scale among the plurality
of light adjustment elements.
[Claim 61
A method of controlling an image display apparatus
including a first light modulation device that includes a
pluralityof displaypixels and modulates light based on input
first image information, an illumination unit that includes
a plurality of light adjustment elements and emits adjusted
light tothe first light modulationdevice, andan illumination
distribution storage unit that stores an illumination range
in which the light emitted from the light adjustment elements
illuminates the display pixels of the first light modulation
device, the method comprising:
alight adjustment informationdecisionstepof deciding
light adjustment information to control the light adjustment
elements of the illumination unit based on a feature amount
of the first image information corresponding to the display
pixels of the illumination range stored in the illumination
distribution storage unit.
[Claim 71
The method of controlling an image display apparatus
according to claim 6,
wherein the illumination distribution storage unit
further stores distribution information of an illumination
intensity with which the light emitted from the light
adjustment elements illuminates the display pixels of the
first light modulation device, and
wherein the method further comprises:
an illumination value cdlculation step of calculating
an illumination value of the light arriving at each of the
display pixels of the first light modulation device based on
the light adjustment information of the illumination unit and
the distribution information of the illumination intensity;
and
an image information generation step of generating
second image information to be set in the first light modulation
device based on the illumination value calculated in the
i
illumination value calculation step and the first image
information.