FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See section 10, rule 13)
“ACTION CONTROL DEVICE AND ACTION
CONTROL METHOD, IMAGING DEVICE, AND PROGRAM”
SONY CORPORATION, of 1-7-1, Konan, Minato-ku, Tokyo
108-0075, Japan
The following specification particularly describes the invention and the manner in
which it is to be performed.
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Description
Title of Invention
ACTION CONTROL DEVICE, ACTION CONTROL METHOD, IMAGING
5 DEVICE, AND PROGRAM
Technical Field
[0001]
The present technology relates to an action control device, an action control
10 method, an imaging device, and a program, and more particularly to an action control
device, an action control method, an imaging device, and a program which are
capable of reducing a focus lag.
Background Art
15 [0002]
In recent years, in the field of compact digital cameras, as the density of
pixels of an image sensor increases, there are cases in which a sense of resolution
deteriorates due to the influence of a small aperture blur.
[0003]
20 In this regard, employment of a neutral density (ND) filter (variabletransmittance
ND filter) that implements a desired transmittance without an aperture
being changed by an applied voltage has been studied. Among ND filters, for
example, a liquid crystal ND filter is used to reduce a drastic change in exposure and
thus reduce an observer’s fatigue by changing a transmittance when a light quantity
25 drastically changes in an eyepiece image at the time of switching of an objective lens
(see Patent Literature 1).
Citation List
Patent Literature
30 [0004]
Patent Literature 1: JP H11-344673A
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Summary of Invention
Technical Problem
[0005]
However, in the case in which the exposure 5 is controlled by changing the
transmittance through the liquid crystal ND filter, when the temperature of the liquid
crystal ND filter is low, a response speed of a liquid crystal decreases. For this
reason, for example, at a timing at which a shutter button is pressed halfway so that
auto focus (AF) is activated before imaging, control of the exposure by the liquid
10 crystal ND filter is likely to be delayed, and thus a focus lag may increase.
[0006]
It is desirable to provide a technique capable of reducing a focus lag that is
caused by a decrease in a response speed of an ND filter that changes a transmittance
according to an applied voltage.
15
Solution to Problem
[0007]
According to the first aspect of the present technology, there is provided an
action control device, including a transmittance specifying unit configured to specify
20 a transmittance of a variable-transmittance neutral density (ND) filter having a
transmittance that varies according to an applied voltage, and an applied voltage
control unit configured to control a voltage to be applied to the variabletransmittance
ND filter such that the transmittance specified by the transmittance
specifying unit is obtained. The applied voltage control unit controls the voltage to
25 be applied to the variable-transmittance ND filter such that the transmittance of the
variable-transmittance ND filter specified by the transmittance specifying unit is
maintained at a timing at which an imaging preparation instruction or an imaging
instruction is given.
[0008]
30 The action control device may further include an imaging unit configured to
image an image through the variable-transmittance ND filter, a transmittance
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calculating unit configured to calculate an appropriate transmittance of the variabletransmittance
ND filter based on brightness of the image imaged by the imaging unit,
and an applied voltage storage unit configured to store an applied voltage
corresponding to a transmittance of the variable-transmittance ND filter. The
applied voltage control unit performs 5 control such that, among applied voltages
stored in the applied voltage storage unit, an applied voltage corresponding to the
appropriate transmittance calculated by the transmittance calculating unit is applied
to the variable-transmittance ND filter.
[0009]
10 The action control device may further include an operating unit configured
to be operated when an imaging preparation instruction or an imaging instruction for
an image to be imaged by the imaging unit is given. The transmittance specifying
unit specifies a transmittance at a certain timing after the applied voltage control unit
starts to apply the applied voltage to the variable-transmittance ND filter. The
15 applied voltage control unit performs control such that, among applied voltages that
are stored in the applied voltage storage unit and correspond to transmittances of the
variable-transmittance ND filter, an applied voltage corresponding to the
transmittance specified by the transmittance specifying unit is applied to the variabletransmittance
ND filter at a timing at which an operation to give the imaging
20 preparation instruction is performed on the operating unit.
[0010]
The action control device may further include a response characteristic data
storage unit configured to store response characteristic data of a transmittance of the
variable-transmittance ND filter that occurs in time series until control from a second
25 voltage from which control of an applied voltage starts to a first voltage is completed
when the applied voltage control unit controls the applied voltage to be the first
voltage, and an elapsed time measuring unit configured to measure an elapsed time
that has elapsed after the applied voltage control unit starts to control the applied
voltage. The transmittance specifying unit specifies a transmittance corresponding
30 to an elapsed time that has elapsed until the operation to give the imaging preparation
instruction is performed on the operating unit after the applied voltage control unit
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starts to apply the applied voltage to the variable-transmittance ND filter, as a
transmittance at the timing at which the operation to give the imaging preparation
instruction is performed on the operating unit, based on the elapsed time measured
by the elapsed time measuring unit and the response characteristic data stored in the
5 response characteristic data storage unit.
[0011]
The action control device may further include a temperature measuring unit
configured to measure a temperature of the variable-transmittance ND filter. The
response characteristic data storage unit stores response characteristic data of a
10 transmittance of the variable-transmittance ND filter that occurs in time series until
control from a second voltage from which control of an applied voltage starts to a
first voltage is completed when the applied voltage control unit controls the applied
voltage to be the first voltage for each temperature of the variable-transmittance ND
filter, and the transmittance specifying unit specifies a transmittance corresponding
15 to an elapsed time that has elapsed until the operation to give the imaging preparation
instruction is performed on the operating unit after the applied voltage control unit
starts to apply the applied voltage to the variable-transmittance ND filter, as a
transmittance at the timing at which the operation to give the imaging preparation
instruction is performed on the operating unit, based on the elapsed time measured
20 by the elapsed time measuring unit, the response characteristic data stored in the
response characteristic data storage unit, and the temperature of the variabletransmittance
ND filter measured by the temperature measuring unit.
[0012]
The action control device may further include a light quantity measuring
25 unit configured to measure light quantities of front and rear portions of the variabletransmittance
ND filter. The transmittance specifying unit specifies a transmittance
at the timing at which the operation to give the imaging preparation instruction is
performed on the operating unit after the applied voltage control unit starts to apply
the applied voltage to the variable-transmittance ND filter, based on the light
30 quantities of the front and rear portions of the variable-transmittance ND filter
measured by the light quantity measuring unit.
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[0013]
The action control device may further include a gain control unit configured
to control a gain of an image to be imaged by the imaging unit, and a shutter control
unit configured to control a light blocking speed for blocking light incident on the
imaging unit at a timing at which an image is imaged by 5 the imaging unit. The gain
of the imaging unit and the light blocking speed or either of them are controlled by
the gain control unit and the shutter control unit so that optimal brightness is
obtained when brightness based on the transmittance acquired by the transmittance
specifying unit is higher or lower than optimal brightness at which the imaging unit
10 images an image.
[0014]
The variable-transmittance ND filter may be a liquid crystal ND filter.
[0015]
The transmittance of the variable-transmittance ND filter may increase or
15 decrease as the applied voltage increases.
[0016]
According to the first aspect of the present technology, there is provided an
action control method of an action control device, including a step of performing a
transmittance specifying process of specifying a transmittance of a variable20
transmittance neutral density (ND) filter having a transmittance that varies according
to an applied voltage, and a step of performing an applied voltage control process of
controlling a voltage to be applied to the variable-transmittance ND filter such that
the transmittance acquired in the transmittance specifying process is obtained. The
applied voltage control process controls the voltage to be applied to the variable25
transmittance ND filter such that the transmittance of the variable-transmittance ND
filter specified by the transmittance specifying process is maintained at a timing at
which an imaging preparation instruction or an imaging instruction is given.
[0017]
According to the first aspect of the present technology, there is a program
30 causing a computer to function as: a transmittance specifying unit configured to
specify a transmittance of a variable-transmittance neutral density (ND) filter having
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a transmittance that varies according to an applied voltage, and an applied voltage
control unit configured to control a voltage to be applied to the variabletransmittance
ND filter such that the transmittance specified by the transmittance
specifying unit is obtained. The applied voltage control unit controls the voltage to
be applied to the variable-transmittance 5 ND filter such that the transmittance of the
variable-transmittance ND filter specified by the transmittance specifying unit is
maintained at a timing at which an imaging preparation instruction or an imaging
instruction is given.
[0018]
10 According to the second aspect of the present technology, there is an
imaging device, including a transmittance specifying unit configured to specify a
transmittance of a variable-transmittance neutral density (ND) filter having a
transmittance that varies according to an applied voltage, and an applied voltage
control unit configured to control a voltage to be applied to the variable15
transmittance ND filter such that the transmittance specified by the transmittance
specifying unit is obtained. The applied voltage control unit controls the voltage to
be applied to the variable-transmittance ND filter such that the transmittance of the
variable-transmittance ND filter specified by the transmittance specifying unit is
maintained at a timing at which an imaging preparation instruction or an imaging
20 instruction is given.
[0019]
In the first and second aspects of the present technology, a transmittance of
a variable-transmittance neutral density (ND) filter having a transmittance that varies
according to an applied voltage is specified, a voltage applied to the variable25
transmittance ND filter is controlled such that the specified transmittance is obtained,
and a voltage applied to the variable-transmittance ND filter is controlled such that
the transmittance of the variable-transmittance ND filter is maintained at a timing at
which an imaging preparation instruction or an imaging instruction is given.
[0020]
30 The action control device or the imaging device according to the present
technology may be an independent device or may be a block that performs an action
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control process or an imaging process.
Advantageous Effects of Invention
[0021]
According to the present technology, 5 it is possible to reduce a focus lag.
Brief Description of Drawings
[0022]
[FIG. 1] FIG. 1 is a diagram illustrating an exemplary configuration of an
10 imaging device according to a first embodiment of the present technology.
[FIG. 2] FIG. 2 is a diagram for describing transmittance characteristics
according to an elapsed time from a timing at which a voltage is applied to a liquid
crystal ND filter.
[FIG. 3] FIG. 3 is a flowchart for describing an action control process
15 performed by the imaging device of FIG. 1.
[FIG. 4] FIG. 4 is a diagram for describing an action control process
performed by the imaging device of FIG. 1.
[FIG. 5] FIG. 5 is a diagram for describing control performed such that a
transmittance of a liquid crystal ND filter at a timing at which a half push operation
20 is performed is maintained.
[FIG. 6] FIG. 6 is a diagram for describing an example in which brightness
that is difficult to control by maintaining a transmittance of a liquid crystal ND filter
is adjusted based on a gain and a shutter speed.
[FIG. 7] FIG. 7 is a diagram illustrating an exemplary configuration of an
25 imaging device according to a second embodiment of the present technology.
[FIG. 8] FIG. 8 is a flowchart for describing an action control process
performed by the imaging device of FIG. 7.
[FIG. 9] FIG. 9 is a diagram for describing an exemplary configuration of a
general-purpose personal computer.
30
Description of Embodiments
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[0023]
Hereinafter, modes (hereinafter referred to as “embodiments”) for carrying
out the invention will be described. The following description will proceed in the
following order.
1. F 5 irst embodiment (example in which transmittance is estimated)
2. Second embodiment (example in which transmittance is measured)
[0024]
<1. First embodiment>
[Exemplary configuration of imaging device according to first embodiment of
10 present technology]
FIG. 1 is a diagram for describing an exemplary configuration of an imaging
device according to a first embodiment of the present technology. The imaging
device of FIG. 1 includes a lens barrel 11, an image processing unit 12, a recording
medium 13, a display processing unit 14, a display unit 15, a control unit 16, and an
15 operating unit 17, and causes an image imaged by an imaging element 46 installed in
the lens barrel 11 to be recorded in the recording medium 13 or to be displayed on
the display unit 15. More specifically, when a half push operation representing
imaging preparation is performed on the operating unit 17 including a shutter button
or the like, the control unit 16 controls the lens barrel 11 such that a focus is
20 controlled. Then, when a full push operation representing an imaging instruction is
performed on the operating unit 17 including the shutter button or the like, the
control unit 16 controls the lens barrel 11 such that an image is imaged. Then, the
lens barrel 11 supplies the imaged image to the image processing unit 12 as an image
signal. The image processing unit 12 performs certain processing on the image
25 signal such as a process of compressing the image signal in a certain data format, and
records the resultant data in the recording medium 13. Alternatively, the image
processing unit 12 performs certain processing on the imaged image signal, supplies
the resultant data to the display processing unit 14, and causes the data to be
displayed on the display unit 15 including a liquid crystal display (LCD) or the like.
30 [0025]
More specifically, the lens barrel 11 includes a zoom lens 41, a diaphragm
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42, a focus lens 43, a liquid crystal ND filter 44, a thermistor 45, and the imaging
element 46, and causes an image of a subject (not shown) to be formed in the
imaging element 46 through the zoom lens 41, and the focus lens 43. Then, the
imaging element 46 images the formed subject image, and outputs the imaged
subject image as an image 5 signal. Further, the control unit 16 controls the
diaphragm 42 such that the diaphragm 42 adjusts a light quantity incident on the lens
barrel 11. The liquid crystal ND filter (liquid crystal variable-transmittance ND
filter) 44 adjusts a light quantity incident on the imaging element 46 by changing the
transmittance by a voltage supplied to the control unit 16. The diaphragm 42 and
10 the liquid crystal ND filter 44 are basically the same in purpose. However, the
liquid crystal ND filter 44 can adjust a light quantity (illuminance) by uniformly
changing the transmittance in the lens barrel 11, but it is difficult for the liquid
crystal ND filter 44 to cope with a drastic change since the liquid crystal ND filter 44
changes the transmittance by the liquid crystal. Meanwhile, since the diaphragm 42
15 adjusts a light quantity by opening and closing an aperture portion, it is difficult to
adjust a light quantity uniformly, but it is possible to adjust a light quantity at a high
speed. The thermistor 45 measures the temperature of the liquid crystal ND filter
44, and supplies the measured temperature to the control unit 16. The imaging
element 46 includes, for example, a charge coupled device (CCD), a complementary
20 metal oxide semiconductor (CMOS), or the like, is controlled by the control unit 16
to image an image, and outputs the imaged image as an image signal.
[0026]
The control unit 16 is configured with a micro computer or the like, and
controls overall operation of the imaging device. More specifically, the control unit
25 16 includes an operation detecting unit 21, a gain control unit 22, a shutter control
unit 23, an ND filter control unit 24, a transmittance-to-voltage table 25, a
temperature-based transmittance-to-time table 26, a time measuring unit 27, a
transmittance specifying unit 28, and an appropriate transmittance calculating unit 29.
The operation detecting unit 21 detects a half push operation representing an imaging
30 preparation instruction or a full push operation representing an imaging instruction
based on an operation signal from the operating unit 17, and outputs a corresponding
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detection signal. The gain control unit 22 performs control such that the imaging
element 46 has a gain of an appropriate state. The shutter control unit 23
appropriately controls the shutter speed when the imaging element 46 performs
imaging. The ND filter control unit 24 controls the transmittance of the liquid
crystal ND filter 44 by controlling a voltage applied 5 to the liquid crystal ND filter 44.
The transmittance-to-voltage table 25 is a table representing a relation between the
transmittance of the liquid crystal ND filter 44 and an applied voltage. Thus, when
the liquid crystal ND filter 44 is set to a certain transmittance, the ND filter control
unit 24 reads an applied voltage corresponding to the certain transmittance with
10 reference to the transmittance-to-voltage table 25, and controls the liquid crystal ND
filter 44 according to the read applied voltage. Here, since it is sufficient if a
necessary applied voltage is obtained from a transmittance, a configuration capable
of calculating an applied voltage through a function capable of calculating an applied
voltage from a transmittance may be used instead of the transmittance-to-voltage
15 table 25.
[0027]
The temperature-based transmittance-to-time table 26 stores a relation
between an elapsed time from a timing at which an applied voltage is changed and
applied when an applied voltage is changed to control the transmittance of the liquid
20 crystal ND filter 44 and a transmittance in the elapsed time as a table for each
temperature of the liquid crystal ND filter 44.
[0028]
In other words, for example, when an applied voltage is changed from a
voltage V12 to a voltage V11 (>V12) and then applied as illustrated by a waveform
25 of an applied voltage at a time t1 in the lower part of FIG. 2, if the temperature of the
liquid crystal ND filter 44 is relatively high, that is, T1, an elapsed time until a
transmittance reaches from a transmittance V1 to a transmittance V2 of a target is a
period of time (t2-t1) as illustrated by a waveform L1 in the upper part of FIG. 2.
However, when the temperature of the liquid crystal ND filter 44 is a temperature T2
30 ( (t2-t1)) as illustrated by a waveform L2 in the upper part of FIG. 2.
Further, when the temperature of the liquid crystal ND filter 44 is a temperature T3
( (t3-t1)> (t2-t1)) as illustrated 5 by a waveform L3 in the upper part of
FIG. 2. In other words, the liquid crystal configuring the liquid crystal ND filter 44
increases in viscosity and thus decreases in the response speed as the temperature
decreases, and so when the applied voltage is changed to increase from the voltage
V12 to the voltage V11, an elapsed time until the transmittance reaches a target level
10 increases.
[0029]
On the other hand, for example, when an applied voltage is changed from a
voltage V11 to a voltage V12 ( (t12-t11)) as illustrated by a waveform L12 in the
upper part of FIG. 2. Further, when the temperature of the liquid crystal ND filter
44 is a temperature T3 ( (t13-t11)> (t12-t11)) as illustrated by a
waveform L13 in the upper part of FIG. 2. In other words, the liquid crystal
configuring the liquid crystal ND filter 44 increases in viscosity and thus decreases in
the response speed as the temperature decreases, and so when the applied voltage is
changed to decrease from the voltage V12 to the voltage V11, an elapsed time until
30 the transmittance reaches a target level increases. In addition, when the applied
voltage decreases, the response speed decreases greater than when the applied
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voltage increases. Accordingly, an elapsed time until the transmittance reaches a
target level increases. Here, FIG. 2 illustrates characteristics when the liquid crystal
ND filter 44 is of a negative type in which the transmittance decreases as the applied
voltage increases, but even when the liquid crystal ND filter 44 is of a positive type
in which the transmittance increases as 5 the applied voltage increases, the response
speed is known to increase as the applied voltage increases.
[0030]
In the temperature-based transmittance-to-time table 26, a relation among an
applied voltage immediately before an applied voltage is applied, an applied voltage
10 to be applied, and the temperature of the liquid crystal ND filter 44 is registered as a
table as illustrated in FIG. 2. Here, since it is sufficient if a relation among an
applied voltage immediately before an applied voltage is applied, an applied voltage
to be applied, and the temperature of the liquid crystal ND filter 44 is obtained, an
approximate function capable of calculating a transmittance using such parameters
15 may be obtained and used instead of the temperature-based transmittance-to-time
table 26.
[0031]
The time measuring unit 27 measures an elapsed time from a timing at
which an applied voltage is changed and then starts to be applied. The
20 transmittance specifying unit 28 specifies the current transmittance of the liquid
crystal ND filter 44 with reference to the temperature-based transmittance-to-time
table 26 based on the elapsed time measured by the time measuring unit 27 and the
temperature of the liquid crystal ND filter 44 measured by the thermistor 45.
[0032]
25 The appropriate transmittance calculating unit 29 calculates an appropriate
transmittance settable by the liquid crystal ND filter 44 based on the image signal
that has been imaged by the imaging element 46 of the lens barrel 11 and then
subjected to certain processing performed by the image processing unit 12.
[0033]
30 When the operation detecting unit 21 detects the half push operation or the
full push operation, the ND filter control unit 24 controls the transmittance
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specifying unit 28, specifies a current transmittance, obtains an applied voltage for
maintaining the specified transmittance with reference to the transmittance-tovoltage
table 25, and applies the applied voltage again. At this time, the gain
control unit 22 and the shutter control unit 23 obtain a degree to which the specified
transmittance is smaller or larger than 5 the target optimal transmittance, and control
either or both of the gain and the shutter speed to compensate for the excess or
deficiency. Through this operation, it is possible to reduce the focus lag caused by
response characteristics of the liquid crystal ND filter 44.
[0034]
10 [Action control process by imaging device of FIG. 1]
Next, an action control process performed when the imaging device of FIG.
1 performs imaging will be described with reference to FIG. 3.
[0035]
In step S1, the control unit 16 controls the imaging element 46 of the lens
15 barrel 11 such that the imaging element 46 images a monitoring image and outputs a
monitoring image signal to the image processing unit 12. The image processing
unit 12 supplies the monitoring image to the control unit 16 and the display control
unit 14. At this time, the display control unit 14 performs certain processing on the
image signal of the monitoring image, and causes the resultant data to be displayed
20 on the display unit 15.
[0036]
In step S2, the control unit 16 controls the appropriate transmittance
calculating unit 29 such that the appropriate transmittance calculating unit 29
calculates the transmittance of the liquid crystal ND filter 44 suitable for imaging.
25 [0037]
In step S3, the ND filter control unit 24 reads information of an applied
voltage for controlling the liquid crystal ND filter 44 such that the liquid crystal ND
filter 44 obtains an appropriate transmittance based on information of the appropriate
transmittance with reference to the transmittance-to-voltage table 25. Then, the ND
30 filter control unit 24 applies the read voltage used to perform control such that the
liquid crystal ND filter 44 has the appropriate transmittance.
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[0038]
In step S4, the time measuring unit 27 measures an elapsed time from a
timing at which an applied voltage is changed and applied. At this time, the time
measuring unit 27 stores an applied voltage immediately before an applied voltage is
5 changed.
[0039]
In step S5, the operation detecting unit 21 determines whether the half push
operation representing the imaging preparation state has been performed on the
operating unit 17. When it is determined in step S5 that the half push operation has
10 not been performed, the process returns to step S1. In other words, until the half
push operation is performed, the process of steps S1 to S5 is repeated, the monitoring
image is continuously imaged, and the transmittance of the liquid crystal ND filter 44
is controlled so that the appropriate transmittance for obtaining an appropriate light
quantity is maintained. In this period, the user views an image displayed on the
15 display unit 15 and can recognize the position imaged by the imaging element 44 of
the lens barrel 11. For example, when monitoring starts from a time t0 in FIG. 4
and the transmittance is controlled from a state of V21 to V22 ( transmittance 32) rather than the transmittance V31 as the half
push operation is performed at a time t51. In this case, the transmittance can be
25 considered to be larger than the appropriate transmittance V32 of the target by (V33-
V32).
[0047]
When the transmittance of the liquid crystal ND filter 44 reaches the
appropriate transmittance V32, the gain and the shutter speed of the imaging element
30 46 and the transmittance of the liquid crystal ND filter 44 are appropriately adjusted
as illustrated in a state Z1 in FIG. 6, and thus the imaging element 46 can image an
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image having appropriate brightness. However, in the state illustrated in FIG. 5,
since a parameter of brightness to be adjusted by the transmittance of the liquid
crystal ND filter 44 does not have an appropriate value as described above as
illustrated in a state Z2 of FIG. 6, a component that deviates from appropriate
brightness is included, and thus it is difficult 5 to perform imaging with appropriate
brightness.
[0048]
In this regard, in the process of step S9, for example, as illustrated in a state
Z3 of FIG. 6, a deviating component that is in an insufficient state by the parameter
10 of brightness to be adjusted by the transmittance of the liquid crystal ND filter 44 is
compensated by the shutter speed of the imaging element 46. Here, FIG. 6
illustrates the example in which the deviating component that is in an insufficient
state by the parameter of brightness to be adjusted by the transmittance of the liquid
crystal ND filter 44 becomes the appropriate brightness as a whole by adjusting the
15 parameter of the shutter speed. However, appropriate brightness may be obtained
as a whole by controlling a parameter for adjusting the gain, or appropriate
brightness may be obtained as a whole by adjusting both parameters.
[0049]
In step S10, the control unit 16 controls the focus lens 43 such that the focus
20 lens 43 performs an AF operation so that a state in which the subject image is formed
in the imaging element 46 is set.
[0050]
In step S11, the operation detecting unit 21 determines whether the half
push operation has been canceled based on the operation signal of the operating unit
25 17. For example, when it is determined in step S11 that the half push operation has
been canceled, the process proceeds to step S14, the AF is canceled, and then the
process returns to step S1. In other words, in this case, the process returns to the
monitoring state.
[0051]
30 However, when it is determined in step S11 that the half push operation has
not been canceled, in step S12, the operation detecting unit 21 determines whether
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the full push operation representing the imaging instruction has been performed
based on the operation signal of the operating unit 17. When it is determined that
the full push operation has not been performed, the process returns to step S11. In
other words, when the half push operation state is continued, the process of steps S11
5 and S12 is repeated.
[0052]
Further, when it is determined in step S12 that the full push operation has
been performed as illustrated at a time t27 of FIG. 4, the process proceeds to step S13.
[0053]
10 In step S13, the gain control unit 22 and the shutter control unit 23 control
the imaging element 46 such that the imaging element 46 images an image with the
appropriate gain and the appropriate shutter speed obtained in the process of step S10,
and then the process proceeds to step S14. Through this process, for example, as
illustrated at the times t27 to t28 of FIG. 4, the imaging element 46 images (captures)
15 an image, and supplies the captured image to the image processing unit 12 as an
image signal. After this process, the process returns to the monitoring process as
illustrated after the time t28. Here, FIG. 4 illustrates the example in which, after the
time t28, the applied voltage returns to the state at the time t23, and the transmittance
reaches V21 at a time t29.
20 [0054]
Through the above process, the liquid crystal ND filter 44 has the
appropriate transmittance as illustrated at the time t23 of FIG. 4, and thus, after the
applied voltage is changed, even when the focus adjustment is locked in the
inappropriate transmittance state as the half push operation is performed at the time
25 t24 that is a timing before the time t26 at which the appropriate transmittance is
obtained, the transmittance is fixed in this state, and it is possible to adjust brightness
that is difficult to adjust in that transmittance by adjusting the gain or the shutter
speed and then perform imaging.
[0055]
30 As a result, it is possible to suppress a focus lag that occurs as the response
speed of the transmittance does not follow the applied voltage applied to the liquid
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crystal ND filter 44.
[0056]
The above description has been made in connection with the example in
which the liquid crystal ND filter is used as an example of the ND filter, but ND
filters of various structures may be used as 5 long as the ND filter changes a
transmittance according to an applied voltage. Further, the liquid crystal ND filter
of the negative type has been described as an example of the ND filter, but the liquid
crystal ND filter of the positive type may be used. Further, the temperature
characteristic of the liquid crystal ND filter has been considered as an example of
10 response characteristics, but a parameter having an influence on the response
characteristics other than the temperature may be considered.
[0057]
<2. Second embodiment>
[Exemplary configuration of imaging device according to second embodiment of
15 present technology]
The above description has been made in connection with the example in
which the transmittance is specified at a timing at which the half push operation is
performed based on an elapsed time from a timing at which an applied voltage is
applied to the liquid crystal ND filter and the temperature of the liquid crystal ND
20 filter with reference to the transmittance-to-time table, and a gain and a shutter speed
for adjusting an applied voltage for maintaining the specified transmittance and a
difference with a target transmittance, that is, a difference with brightness to be
adjusted by the liquid crystal ND filter, are calculated. However, as the
transmittance at the timing at which the half push operation is performed, the
25 transmittance of the liquid crystal ND filter may be measured at the corresponding
timing and used.
[0058]
FIG. 7 illustrates an exemplary configuration of a second embodiment of an
imaging device that is configured to measure and use the transmittance of the liquid
30 crystal ND filter at a timing at which the half push operation is performed. In the
imaging device of FIG. 7, components having the same function as the components
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of the imaging device of FIG. 1 have the same names and are denoted by the same
reference numerals, and thus a description thereof will be appropriately omitted.
[0059]
In other words, the imaging device of FIG. 7 differs from the imaging device
of FIG. 1 in that a liquid crystal ND filter 101 5 and a light quantity measuring unit 102
are provided instead of the liquid crystal ND filter 44 and the thermistor 45. Further,
the control unit 16 includes an ND filter control unit 111 and a transmittance
specifying unit 112 instead of the ND filter control unit 24, the temperature-based
transmittance-to-time table 26, the time measuring unit 27, and the transmittance
10 specifying unit 28. The liquid crystal ND filter 101 has basically the same function
as the liquid crystal ND filter 24 but is configured to have a portion protruding from
the inner diameter of the lens barrel 11. Further, the light quantity measuring unit
102 includes measuring units 102a and 102b that are configured such that the portion
of the liquid crystal ND filter 101 protruding from the lens barrel 111 is interposed
15 therebetween, and that measure light quantities of a front portion and a rear portion
of the liquid crystal ND filter 101, and supply the light quantities measured at the
respective positions to the control unit 16. In other words, the measuring unit 102a
of the light quantity measuring unit 102 installed in front of the liquid crystal ND
filter 101 measures a light quantity before light is incident on the liquid crystal ND
20 filter 101. Further, the measuring unit 102b of the light quantity measuring unit 102
installed behind the liquid crystal ND filter 101 measures a light quantity after light
is incident on the liquid crystal ND filter 101.
[0060]
The ND filter control unit 111 is basically the same as the ND filter control
25 unit 24, but uses a value specified by the transmittance specifying unit 112 as the
transmittance of the liquid crystal ND filter 101 at a timing at which the half push
operation is performed. The transmittance specifying unit 112 calculates and
specifies a transmittance based on a ratio of the light quantities of the front and rear
portions of the liquid crystal ND filter 101 which are supplied from the light quantity
30 measuring unit 102.
[0061]
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[Action control process by imaging device of FIG. 7]
Next, an action control process performed when the imaging device of FIG.
7 performs imaging will be described with reference to a flowchart of FIG. 8. The
flowchart of FIG. 8 other than step S36 is identical to the flowchart of FIG. 3 in the
process of steps S1 to S5 and steps S7 to 5 S14, and thus a description thereof will be
omitted.
[0062]
In other words, in the process of steps S31 to S35, a monitoring image is
imaged, and the same process is repeated until the half push operation is performed.
10 Then, when it is determined in step S35 that the half push operation has been
performed, the process proceeds to step S36.
[0063]
In step S36, the transmittance specifying unit 112 calculates the ratio of the
light quantities of the front and rear portions of the liquid crystal ND filter 44
15 measured by the light quantity measuring unit 102, and specifies the current
transmittance of the liquid crystal ND filter.
[0064]
Then, in step S37, the ND filter control unit 111 reads the applied voltage
corresponding to the specified transmittance of the liquid crystal ND filter 44 from
20 the transmittance-to-voltage table 25, and in step S38, the read applied voltage is
applied to the liquid crystal ND filter, and the transmittance at a timing at which the
half push operation has been performed is locked. Then, in step S39, a gain and a
shutter speed used to adjust brightness that is difficult to adjust by the liquid crystal
ND filter 101 are calculated based on the difference between the transmittance at a
25 timing at which the half push operation has been performed and the target
transmittance, and then the AF is performed in step S40. Lastly, when the operating
unit 17 is pushed fully so that an imaging instruction is given in step S42, in step S43,
an image is imaged based on the transmittance of the liquid crystal ND filter at a
timing at which the half push operation has been performed and the gain and the
30 shutter speed calculated by the process of step S39.
[0065]
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Through the above process, the imaging device of FIG. 1 directly measures
the transmittance of the liquid crystal ND filter 44 at a timing at which the operating
unit is pushed halfway and obtains an accurate transmittance, and thus it is possible
to calculate an applied voltage to be applied to the liquid crystal ND filter with a high
degree of accuracy. Further, since the transmittance 5 of the liquid crystal ND filter
44 at a timing at which the half push operation is performed is accurately obtained, a
gain and a shutter speed used to adjust brightness that is difficult to adjust by the
liquid crystal ND filter can be controlled with a high degree of accuracy.
[0066]
10 Accordingly, it is possible to reduce a focus lag that occurs as the response
speed of the transmittance does not follow the applied voltage applied to the liquid
crystal ND filter.
[0067]
The series of processes described above can be executed by hardware but
15 can also be executed by software. When the series of processes is executed by
software, a program that constructs such software is installed into a computer. Here,
the expression “computer” includes a computer in which dedicated hardware is
incorporated and a general-purpose personal computer or the like that is capable of
executing various functions when various programs are installed.
20 [0068]
FIG. 9 is a block diagram showing a hardware configuration example of a
computer that performs the above-described series of processing using a program.
[0069]
In the computer, a central processing unit (CPU) 1001, a read only memory
25 (ROM) 1002 and a random access memory (RAM) 1003 are mutually connected by a
bus 1004.
[0070]
An input/output interface 1005 is also connected to the bus 1004. An input
unit 1006, an output unit 1007, a storage unit 1008, a communication unit 1009, and
30 a drive 1010 are connected to the input/output interface 1005.
[0071]
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The input unit 1006 is configured from a keyboard, a mouse, a microphone
or the like. The output unit 1007 is configured from a display, a speaker or the like.
The storage unit 1008 is configured from a hard disk, a non-volatile memory or the
like. The communication unit 1009 is configured from a network interface or the
like. The drive 1010 drives a removable 5 medium 1011 such as a magnetic disk, an
optical disk, a magneto-optical disk, a semiconductor memory or the like.
[0072]
In the computer configured as described above, the CPU 1001 loads a
program that is stored, for example, in the storage unit 1008 onto the RAM 1003 via
10 the input/output interface 1005 and the bus 1004, and executes the program. Thus,
the above-described series of processing is performed.
[0073]
Programs to be executed by the computer (the CPU 1001) are provided
being recorded in the removable medium 1011 which is a packaged medium or the
15 like. Also, programs may be provided via a wired or wireless transmission medium,
such as a local area network, the Internet or digital satellite broadcasting.
[0074]
Then, by inserting the removable medium 1011 into the drive 1010, the
program can be installed in the storage unit 1008 via the input/output interface 1005.
20 Further, the program can be received by the communication unit 1009 via a wired or
wireless transmission medium and installed in the storage unit 1008. Moreover, the
program can be installed in advance in the ROM 1002 or the storage unit 1008.
[0075]
It should be noted that the program executed by a computer may be a
25 program that is processed in time series according to the sequence described in this
specification or a program that is processed in parallel or at necessary timing such as
upon calling.
[0076]
Further, in the present disclosure, a system has the meaning of a set of a
30 plurality of configured elements (such as an apparatus or a module (part)), and does
not take into account whether or not all the configured elements are in the same
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casing. Therefore, the system may be either a plurality of apparatuses, stored in
separate casings and connected through a network, or a plurality of modules within a
single casing.
[0077]
An 5 embodiment of the disclosure is not limited to the embodiments
described above, and various changes and modifications may be made without
departing from the scope of the disclosure.
[0078]
For example, the present disclosure can adopt a configuration of cloud
10 computing which processes by allocating and connecting one function by a plurality
of apparatuses through a network.
[0079]
Further, each step described by the above mentioned flow charts can be
executed by one apparatus or by allocating a plurality of apparatuses.
15 [0080]
Further, each step described by the above mentioned flow charts can be
executed by one apparatus or by allocating a plurality of apparatuses.
[0081]
Additionally, the present technology may also be configured as below.
20 (1)
An action control device, including:
a transmittance specifying unit configured to specify a transmittance of a
variable-transmittance neutral density (ND) filter having a transmittance that varies
according to an applied voltage; and
25 an applied voltage control unit configured to control a voltage to be applied
to the variable-transmittance ND filter such that the transmittance specified by the
transmittance specifying unit is obtained;
wherein the applied voltage control unit controls the voltage to be applied to
the variable-transmittance ND filter such that the transmittance of the variable30
transmittance ND filter specified by the transmittance specifying unit is maintained
at a timing at which an imaging preparation instruction or an imaging instruction is
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given.
(2)
The action control device according to (1), further including:
an imaging unit configured to image an image through the variable-
5 transmittance ND filter;
a transmittance calculating unit configured to calculate an appropriate
transmittance of the variable-transmittance ND filter based on brightness of the
image imaged by the imaging unit; and
an applied voltage storage unit configured to store an applied voltage
10 corresponding to a transmittance of the variable-transmittance ND filter,
wherein the applied voltage control unit performs control such that, among
applied voltages stored in the applied voltage storage unit, an applied voltage
corresponding to the appropriate transmittance calculated by the transmittance
calculating unit is applied to the variable-transmittance ND filter.
15 (3)
The action control device according to (1) or (2), further including:
an operating unit configured to be operated when an imaging preparation
instruction or an imaging instruction for an image to be imaged by the imaging unit
is given,
20 wherein the transmittance specifying unit specifies a transmittance at a
certain timing after the applied voltage control unit starts to apply the applied voltage
to the variable-transmittance ND filter, and
wherein the applied voltage control unit performs control such that, among
applied voltages that are stored in the applied voltage storage unit and correspond to
25 transmittances of the variable-transmittance ND filter, an applied voltage
corresponding to the transmittance specified by the transmittance specifying unit is
applied to the variable-transmittance ND filter at a timing at which an operation to
give the imaging preparation instruction is performed on the operating unit.
(4)
30 The action control device according to any one of (1) to (3), further
including:
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a response characteristic data storage unit configured to store response
characteristic data of a transmittance of the variable-transmittance ND filter that
occurs in time series until control from a second voltage from which control of an
applied voltage starts to a first voltage is completed when the applied voltage control
5 unit controls the applied voltage to be the first voltage; and
an elapsed time measuring unit configured to measure an elapsed time that
has elapsed after the applied voltage control unit starts to control the applied voltage,
wherein the transmittance specifying unit specifies a transmittance
corresponding to an elapsed time that has elapsed until the operation to give the
10 imaging preparation instruction is performed on the operating unit after the applied
voltage control unit starts to apply the applied voltage to the variable-transmittance
ND filter, as a transmittance at the timing at which the operation to give the imaging
preparation instruction is performed on the operating unit, based on the elapsed time
measured by the elapsed time measuring unit and the response characteristic data
15 stored in the response characteristic data storage unit.
(5)
The action control device according to any one of (1) to (4), further
including:
a temperature measuring unit configured to measure a temperature of the
20 variable-transmittance ND filter,
wherein the response characteristic data storage unit stores response
characteristic data of a transmittance of the variable-transmittance ND filter that
occurs in time series until control from a second voltage from which control of an
applied voltage starts to a first voltage is completed when the applied voltage control
25 unit controls the applied voltage to be the first voltage for each temperature of the
variable-transmittance ND filter, and
wherein the transmittance specifying unit specifies a transmittance
corresponding to an elapsed time that has elapsed until the operation to give the
imaging preparation instruction is performed on the operating unit after the applied
30 voltage control unit starts to apply the applied voltage to the variable-transmittance
ND filter, as a transmittance at the timing at which the operation to give the imaging
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preparation instruction is performed on the operating unit, based on the elapsed time
measured by the elapsed time measuring unit, the response characteristic data stored
in the response characteristic data storage unit, and the temperature of the variabletransmittance
ND filter measured by the temperature measuring unit.
5 (6)
The action control device according to any one of (1) to (3), further
including:
a light quantity measuring unit configured to measure light quantities of
front and rear portions of the variable-transmittance ND filter,
10 wherein the transmittance specifying unit specifies a transmittance at the
timing at which the operation to give the imaging preparation instruction is
performed on the operating unit after the applied voltage control unit starts to apply
the applied voltage to the variable-transmittance ND filter, based on the light
quantities of the front and rear portions of the variable-transmittance ND filter
15 measured by the light quantity measuring unit.
(7)
The action control device according to any one of (1) to (6), further
including:
a gain control unit configured to control a gain of an image to be imaged by
20 the imaging unit; and
a shutter control unit configured to control a light blocking speed for
blocking light incident on the imaging unit at a timing at which an image is imaged
by the imaging unit,
wherein the gain of the imaging unit and the light blocking speed, or either
25 of them are controlled by the gain control unit and the shutter control unit so that
optimal brightness is obtained when brightness based on the transmittance acquired
by the transmittance specifying unit is higher or lower than optimal brightness at
which the imaging unit images an image.
(8)
30 The action control device according to any one of (1) to (7),
wherein the variable-transmittance ND filter is a liquid crystal ND filter.
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(9)
The action control device according to any one of (1) to (8),
wherein the transmittance of the variable-transmittance ND filter increases
or decreases as the applied voltage increases.
5 (10)
An action control method of an action control device, including:
a step of performing a transmittance specifying process of specifying a
transmittance of a variable-transmittance neutral density (ND) filter having a
transmittance that varies according to an applied voltage; and
10 a step of performing an applied voltage control process of controlling a
voltage to be applied to the variable-transmittance ND filter such that the
transmittance acquired in the transmittance specifying process is obtained;
wherein the applied voltage control process controls the voltage to be
applied to the variable-transmittance ND filter such that the transmittance of the
15 variable-transmittance ND filter specified by the transmittance specifying process is
maintained at a timing at which an imaging preparation instruction or an imaging
instruction is given.
(11)
A program causing a computer to function as:
20 a transmittance specifying unit configured to specify a transmittance of a
variable-transmittance neutral density (ND) filter having a transmittance that varies
according to an applied voltage; and
an applied voltage control unit configured to control a voltage to be applied
to the variable-transmittance ND filter such that the transmittance specified by the
25 transmittance specifying unit is obtained;
wherein the applied voltage control unit controls the voltage to be applied to
the variable-transmittance ND filter such that the transmittance of the variabletransmittance
ND filter specified by the transmittance specifying unit is maintained
at a timing at which an imaging preparation instruction or an imaging instruction is
30 given.
(12)
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An imaging device, including:
a transmittance specifying unit configured to specify a transmittance of a
variable-transmittance neutral density (ND) filter having a transmittance that varies
according to an applied voltage; and
an applied voltage control unit configured 5 to control a voltage to be applied
to the variable-transmittance ND filter such that the transmittance specified by the
transmittance specifying unit is obtained;
wherein the applied voltage control unit controls the voltage to be applied to
the variable-transmittance ND filter such that the transmittance of the variable10
transmittance ND filter specified by the transmittance specifying unit is maintained
at a timing at which an imaging preparation instruction or an imaging instruction is
given.
Reference Signs List
15 [0082]
11 lens barrel
12 image processing unit
13 recording medium
14 display processing unit
20 15 display unit
16 control unit
17 operating unit
21 operation detecting unit
22 gain control unit
25 23 shutter control unit
24 ND filter control unit
25 transmittance-to-voltage table
26 temperature-based transmittance-to-time table
27 time measuring unit
30 28 transmittance specifying unit
29 appropriate transmittance calculating unit
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41 zoom lens
42 diaphragm
43 focus lens
44 liquid crystal ND filter
5 45 thermistor
46 imaging element
101 liquid crystal ND filter
102 light quantity measuring unit
102a, 102b measuring unit
10 111 ND filter
112 transmittance specifying unit
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CLAIMS
Claim 1
An action control device, comprising:
a transmittance specifying unit configured to specify a transmittance of a
variable-transmittance neutral density (N 5 D) filter having a transmittance that varies
according to an applied voltage; and
an applied voltage control unit configured to control a voltage to be applied
to the variable-transmittance ND filter such that the transmittance specified by the
transmittance specifying unit is obtained;
10 wherein the applied voltage control unit controls the voltage to be applied to
the variable-transmittance ND filter such that the transmittance of the variabletransmittance
ND filter specified by the transmittance specifying unit is maintained
at a timing at which an imaging preparation instruction or an imaging instruction is
given.
15
Claim 2
The action control device according to claim 1, further comprising:
an imaging unit configured to image an image through the variabletransmittance
ND filter;
20 a transmittance calculating unit configured to calculate an appropriate
transmittance of the variable-transmittance ND filter based on brightness of the
image imaged by the imaging unit; and
an applied voltage storage unit configured to store an applied voltage
corresponding to a transmittance of the variable-transmittance ND filter,
25 wherein the applied voltage control unit performs control such that, among
applied voltages stored in the applied voltage storage unit, an applied voltage
corresponding to the appropriate transmittance calculated by the transmittance
calculating unit is applied to the variable-transmittance ND filter.
30 Claim 3
The action control device according to claim 2, further comprising:
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an operating unit configured to be operated when an imaging preparation
instruction or an imaging instruction for an image to be imaged by the imaging unit
is given,
wherein the transmittance specifying unit specifies a transmittance at a
certain timing after the applied voltage control unit 5 starts to apply the applied voltage
to the variable-transmittance ND filter, and
wherein the applied voltage control unit performs control such that, among
applied voltages that are stored in the applied voltage storage unit and correspond to
transmittances of the variable-transmittance ND filter, an applied voltage
10 corresponding to the transmittance specified by the transmittance specifying unit is
applied to the variable-transmittance ND filter at a timing at which an operation to
give the imaging preparation instruction is performed on the operating unit.
Claim 4
15 The action control device according to claim 3, further comprising:
a response characteristic data storage unit configured to store response
characteristic data of a transmittance of the variable-transmittance ND filter that
occurs in time series until control from a second voltage from which control of an
applied voltage starts to a first voltage is completed when the applied voltage control
20 unit controls the applied voltage to be the first voltage; and
an elapsed time measuring unit configured to measure an elapsed time that
has elapsed after the applied voltage control unit starts to control the applied voltage,
wherein the transmittance specifying unit specifies a transmittance
corresponding to an elapsed time that has elapsed until the operation to give the
25 imaging preparation instruction is performed on the operating unit after the applied
voltage control unit starts to apply the applied voltage to the variable-transmittance
ND filter, as a transmittance at the timing at which the operation to give the imaging
preparation instruction is performed on the operating unit, based on the elapsed time
measured by the elapsed time measuring unit and the response characteristic data
30 stored in the response characteristic data storage unit.
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Claim 5
The action control device according to claim 4, further comprising:
a temperature measuring unit configured to measure a temperature of the
variable-transmittance ND filter,
wherein the response characteristic 5 data storage unit stores response
characteristic data of a transmittance of the variable-transmittance ND filter that
occurs in time series until control from a second voltage from which control of an
applied voltage starts to a first voltage is completed when the applied voltage control
unit controls the applied voltage to be the first voltage for each temperature of the
10 variable-transmittance ND filter, and
wherein the transmittance specifying unit specifies a transmittance
corresponding to an elapsed time that has elapsed until the operation to give the
imaging preparation instruction is performed on the operating unit after the applied
voltage control unit starts to apply the applied voltage to the variable-transmittance
15 ND filter, as a transmittance at the timing at which the operation to give the imaging
preparation instruction is performed on the operating unit, based on the elapsed time
measured by the elapsed time measuring unit, the response characteristic data stored
in the response characteristic data storage unit, and the temperature of the variabletransmittance
ND filter measured by the temperature measuring unit.
20
Claim 6
The action control device according to claim 3, further comprising:
a light quantity measuring unit configured to measure light quantities of
front and rear portions of the variable-transmittance ND filter,
25 wherein the transmittance specifying unit specifies a transmittance at the
timing at which the operation to give the imaging preparation instruction is
performed on the operating unit after the applied voltage control unit starts to apply
the applied voltage to the variable-transmittance ND filter, based on the light
quantities of the front and rear portions of the variable-transmittance ND filter
30 measured by the light quantity measuring unit.
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Claim 7
The action control device according to claim 1, further comprising:
a gain control unit configured to control a gain of an image to be imaged by
the imaging unit; and
a shutter control unit configured 5 to control a light blocking speed for
blocking light incident on the imaging unit at a timing at which an image is imaged
by the imaging unit,
wherein the gain of the imaging unit and the light blocking speed, or either
of them are controlled by the gain control unit and the shutter control unit so that
10 optimal brightness is obtained when brightness based on the transmittance acquired
by the transmittance specifying unit is higher or lower than optimal brightness at
which the imaging unit images an image.
Claim 8
15 The action control device according to claim 1,
wherein the variable-transmittance ND filter is a liquid crystal ND filter.
Claim 9
The action control device according to claim 1,
20 wherein the transmittance of the variable-transmittance ND filter increases
or decreases as the applied voltage increases.
Claim 10
An action control method of an action control device, comprising:
25 a step of performing a transmittance specifying process of specifying a
transmittance of a variable-transmittance neutral density (ND) filter having a
transmittance that varies according to an applied voltage; and
a step of performing an applied voltage control process of controlling a
voltage to be applied to the variable-transmittance ND filter such that the
30 transmittance acquired in the transmittance specifying process is obtained;
wherein the applied voltage control process controls the voltage to be
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applied to the variable-transmittance ND filter such that the transmittance of the
variable-transmittance ND filter specified by the transmittance specifying process is
maintained at a timing at which an imaging preparation instruction or an imaging
instruction is given.
5
Claim 11
A program causing a computer to function as:
a transmittance specifying unit configured to specify a transmittance of a
variable-transmittance neutral density (ND) filter having a transmittance that varies
10 according to an applied voltage; and
an applied voltage control unit configured to control a voltage to be applied
to the variable-transmittance ND filter such that the transmittance specified by the
transmittance specifying unit is obtained;
wherein the applied voltage control unit controls the voltage to be applied to
15 the variable-transmittance ND filter such that the transmittance of the variabletransmittance
ND filter specified by the transmittance specifying unit is maintained
at a timing at which an imaging preparation instruction or an imaging instruction is
given.
20 Claim 12
An imaging device, comprising:
a transmittance specifying unit configured to specify a transmittance of a
variable-transmittance neutral density (ND) filter having a transmittance that varies
according to an applied voltage; and
25 an applied voltage control unit configured to control a voltage to be applied
to the variable-transmittance ND filter such that the transmittance specified by the
transmittance specifying unit is obtained;
wherein the applied voltage control unit controls the voltage to be applied to
the variable-transmittance ND filter such that the transmittance of the variable30
transmittance ND filter specified by the transmittance specifying unit is maintained
at a timing at which an imaging preparation instruction or an imaging instruction is