JPH08182004A - Iris controller for frame sequential color camera - Google Patents

Abstract

(57) [Abstract] [Purpose] In a frame-sequential color camera, iris control is performed by an electronic shutter to reduce the size and weight of the camera and improve its performance. An iris control device for a frame-sequential color camera, including initial time setting means (9, 17) for setting the image accumulation time of the solid-state image sensor corresponding to each color to the same time when color balance is set, and an initial time. An arithmetic means (9) for obtaining a color balance correction signal based on the signal value of each color obtained from the solid-state image sensor by imaging the subject for color balance adjustment after the setting by the setting means, and a solid-state image sensor based on the color balance correction signal. Shutter time setting means (5, 1) for setting the color balance by adjusting the image accumulation time for each color in (4)
0) and iris control means (9, 10, 5) that adjusts the image accumulation time of each color while maintaining the set color balance state based on the iris setting signal at the time of imaging the subject after the color balance setting. .

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an iris control device for a frame-sequential color camera, and more particularly to a frame-sequential color camera using a solid-state image pickup device capable of operating an electronic shutter, which is electronically controlled by a simple device configuration. The present invention relates to a technique that enables an exposure amount to be set to an appropriate value.

[0002]

2. Description of the Related Art In a color camera using a solid-state image sensor or the like, for example, a frame-sequential color camera using a solid-state image sensor such as a CCD, the amount of image light incident on the solid-state image sensor is determined according to the brightness of a subject. It is necessary to adjust to an appropriate value. Conventionally, aperture control for setting the light amount of such image light to an appropriate value has been performed by adjusting an aperture (iris) provided in the imaging lens. Adjust the iris manually, or obtain the iris control signal from the image signal obtained by the solid-state image sensor,
An automatic iris that automatically adjusts based on this iris control signal has been performed.

[0003]

However, in order to control the aperture by the auto iris mechanism, a mechanism for driving the iris is required around the image pickup lens, and the size of the lens peripheral portion becomes large and the weight also increases. Furthermore, a circuit for driving the iris is also required. Therefore, it is difficult to reduce the size and weight of the camera provided with the auto iris mechanism.

Further, in a camera that manually adjusts the iris, there is a problem that a camera position shift or a focus shift occurs when the iris ring provided on the imaging lens is adjusted.

Therefore, in view of the problems in the above-described conventional color camera, it is an object of the present invention to appropriately adjust the iris in a frame sequential color camera with a simple device configuration and without hindering the reduction in size and weight of the camera. Is to be able to do.

It is another object of the present invention to appropriately adjust the iris of a frame sequential color camera without adjusting the camera position or the focus when the iris is adjusted.

[0007]

In order to achieve the above object, in an iris control device for a frame sequential color camera according to the present invention, a color filter for color-separating image light of an object received through an imaging lens, The image storage time of the solid-state image sensor that captures the image light separated by the color filter and that can operate the electronic shutter and the solid-state image sensor that corresponds to each color according to the color balance setting command have the same or predetermined time. To obtain the color balance correction signal based on the signal value of each color obtained from the solid-state image sensor by imaging the color balance adjustment subject after the initial time setting means for setting the ratio and the setting by the initial time setting means. And adjusting the image storage time for each color of the solid-state image sensor based on the color balance correction signal. The shutter time setting means for setting the balance and the iris control means for adjusting the image storage time of each color while maintaining the set color balance state based on the iris setting signal at the time of imaging the subject after the color balance setting. Set up.

The calculating means further obtains an exposure correction signal necessary for obtaining an appropriate light amount from the signal value of each color obtained from the solid-state image pickup device, and the iris control means is set based on the exposure correction signal. By adjusting the image storage time of the solid-state image pickup device while maintaining the color balance, it is possible to automatically obtain a proper exposure.

Further, a manual aperture control means for manually setting the exposure is provided, while the iris control means maintains the color balance set by the iris setting signal obtained based on the setting of the manual aperture control means. It may be configured to control the image storage time of the solid-state image sensor.

Further, it has initial shutter time input means for setting the image storage time of each color to the same desired value, and proper light amount display means for indicating that the image storage time is a proper value, The color balance may be set after the proper light amount display means displays the proper light amount input state by adjusting the image storage means by the shutter time input means.

Further, the image pickup lens may be provided with a diaphragm mechanism for adjusting the amount of incident light of subject image light.

[0012]

In the iris control device having the above-described structure, the color balance setting command is given in advance by the color balance setting switch while picking up an image of the color balance adjusting subject, for example, white paper or white light of a color viewer. In response to this, the initial time setting means sets the image storage time of the solid-state image sensor to the same or a predetermined time ratio. Then, in this state, the calculating means calculates the color balance correction signal based on the signal value of each color obtained from the solid-state image sensor, and the shutter time setting means calculates the color balance correction signal for each color of the solid-state image sensor based on the color balance correction signal. Adjust the image storage time and set the color balance.

After the color balance is set in this way, when an image of a desired subject is taken, the iris control means operates as described above on the basis of an iris setting signal applied manually or automatically. The iris control is performed by adjusting the image storage time of each color while maintaining the color balance state set by, that is, while keeping the ratio of the image storage time of each color constant. This makes it possible to electronically control the aperture of a frame-sequential color camera, eliminates the need for an iris control mechanism and iris drive circuit around the image pickup lens, and reduces the size and weight of the camera appropriately. Adjustments can be made. Further, even when the iris adjustment is performed manually, it is not necessary to adjust the iris ring of the lens, so that the displacement of the camera position or the displacement of the focus does not occur, and it is possible to perform appropriate imaging.

Further, the calculation means obtains an iris setting signal required to obtain an appropriate amount of light from the signal value of each color obtained from the solid-state image pickup device, and the iris control means is set based on the iris setting signal. By adjusting the image storage time of the solid-state image sensor while maintaining the color balance, it is possible to automatically obtain proper exposure.
Also in this case, the auto iris mechanism around the imaging lens and its drive circuit are not needed, and the camera can be made smaller and lighter.

Furthermore, in order to set the exposure manually,
For example, a key switch or other manual aperture control means is provided,
By the iris setting signal obtained based on the setting of the manual aperture control means, the iris control means can control the image storage time of the solid-state image pickup device while maintaining the set color balance. In this case, by inputting a desired aperture value or the like with a key switch or the like, the image storage time of the solid-state image sensor is controlled so that the state becomes equivalent to the aperture value. Also in this case, the iris can be electronically controlled, and the iris mechanism of the camera can be simplified because the iris can be set by a manual aperture control means such as a key switch that can be operated with a small stroke and a weak force. It is possible to eliminate inconveniences such as a camera position shift or a focus shift at the time of image pickup.

Further, when the initial shutter time input means for setting the image storage time of each color to the same desired value and the appropriate light amount display means for indicating that the image storage time is an appropriate value are provided, the initial shutter time is set. It is possible to sequentially input various image storage times through the input means, and to know that the image storage time has reached an appropriate value through the appropriate light amount display means. Then, by setting the color balance in such a state that the image storage time becomes an appropriate value, that is, in the state of inputting the appropriate light amount, the color balance is set extremely appropriately. Thereby, when a desired subject is imaged thereafter, the iris control is performed while the state in which the color balance is appropriately set is maintained, and the image can be captured in an appropriate exposure state.

Further, when the imaging lens is provided with a diaphragm mechanism for adjusting the incident light amount of the object image light in combination with the iris control by the electronic shutter as described above, the object image light having an extremely wide range of brightness can be obtained. On the other hand, it becomes possible to appropriately control the aperture, and a camera with a wide range of applications can be realized.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic configuration of a frame sequential color camera equipped with an iris control device according to an embodiment of the present invention. The color camera shown in FIG. 1 has an image pickup lens 2 for forming image light of an object 1 on an image pickup surface of an image pickup device 4, and color separation for rotatably arranged between the image pickup lens 2 and the solid-state image pickup device 4. The color filter 3 of FIG. The apparatus of FIG. 1 also includes the image pickup device 4 such as a CCD, and the image pickup device 4 is capable of electronic shutter operation as described in detail later.

[0019]

The apparatus of FIG. 1 further receives an amplifier circuit 6 for amplifying the image pickup signal output of the image pickup device 4, a sample hold circuit 7 to which the output of the amplifier circuit 6 is supplied, and a signal from the sample hold circuit 7. An arithmetic unit 9 including a multiplexer circuit 8 and a microprocessor is provided. The arithmetic unit 9 also includes a memory for temporarily storing image data of each color. The apparatus of FIG. 1 also includes a signal processing circuit 12 for processing the signal from the multiplexer circuit 8 and outputting the desired color video signal.

The apparatus of FIG. 1 also includes an image pickup element drive circuit 5 for generating a drive signal to be supplied to the image pickup element 4, and a synchronization signal generation circuit 10 for generating each control pulse supplied to the image pickup element drive circuit 5. A color filter driving device 11 such as a motor for rotationally driving the rotary color filter 3 based on a control signal from the synchronizing signal generating circuit 10,
A rotation detector 13 such as a photo interrupter for detecting the rotation of the rotary color filter 3 is provided. The output of the rotation detector 13 is the synchronization signal generation circuit 1
0 has been entered. The synchronization signal generation circuit 10 supplies various control signals to the image sensor drive circuit 5 and the color filter drive device 11 as described above.

Further, the arithmetic unit 9 is connected to a white balance setting switch 14 for giving a command for setting white balance, and a manual aperture setting device 15 for manually performing aperture control.
The manual aperture setting device 15 includes, for example, a soft-touch key switch, and is configured to input a desired aperture setting value or exposure setting information. Further, the computing device 9 displays the proper light amount LE for displaying the proper light amount state.
A D (light emitting diode) 16 is connected. further,
An initial shutter time setting switch 17 for manually setting the image storage time of the solid-state image sensor 4 is connected to the synchronization signal generation circuit 10.

FIG. 2 shows a detailed structure of the rotary color filter 3 for color separation used in the apparatus of FIG. Figure 2
The color filter 3 of No. 1 includes filter regions 18, 19, 20 of red (R), green (G), and blue (B) that are divided at equal angles of 120 degrees. The filter region 18 is configured to transmit only red light, the filter region 19 is configured to transmit only green light, and the filter region 20 is configured to transmit only blue light. Such a color filter 3 is rotated around the rotation shaft 21 by the driving device 11 in synchronization with the scanning timing of the solid-state image sensor 4. FIG. 2 shows the positional relationship between the rotary color filter 3 and the solid-state image sensor 4 as described above.

Further, the color filter 3 is formed with a plurality of opaque regions 22 and 22a arranged at equal intervals on the outer periphery thereof. These opaque areas 22 and 22a are
The rotation detector 13 shown in FIG.
It is used to obtain a signal according to the rotation of. The opaque area 22a having a size different from that of the other opaque areas 22 is 1
In order to detect the region 19 (that is, the green (G) region) in the rotation, the size is different from that of the other regions 22.

As the solid-state image pickup device used in the apparatus according to the present invention, a device capable of electronic shutter operation is used. That is, a pixel which has a charge storage type pixel, whose storage time can be controlled, and which can be reset is used. FIG. 3A shows a configuration example of the solid-state image sensor 4 which can perform such an electronic shutter operation and is used in the frame sequential color camera of FIG. The solid-state image sensor in the figure is a plurality of light-receiving elements arranged in a two-dimensional matrix,
That is, the photodiode 23 and the vertical transfer CCD 24 that receives the charge signal corresponding to the image light from the photodiode 23 through the field shift gate (not shown) and transfers it in the vertical direction, that is, from the top to the bottom in the drawing.
And a horizontal transfer CCD 25 that sequentially transfers the video signal charges from the vertical pixels sequentially transferred from each vertical transfer CCD 24 in the horizontal direction. In addition, horizontal transfer C
An amplifier 26 is provided to take out the output of the CD 25 as a video signal output to the outside.

In such a solid-state image pickup device, image light of a subject (not shown) is applied to each pixel, that is, the photodiode 23, and charges corresponding to the intensity of the image light at the position of each pixel pass through a field shift gate (not shown). A vertical transfer CCD adjacent to each photodiode 23 between the nth field and the (n + 1) th field via
24. Then, the vertical transfer CCD 24 sequentially transfers the image charges input from the respective photodiodes 23 in this manner and supplies the image charges to the horizontal transfer CCD 25. The horizontal transfer CCD 25 also sequentially transfers the charges supplied from the vertical transfer CCD 24 in the horizontal direction, and supplies the charges to the outside as a video signal output via the amplifier 26.

Such a solid-state image sensor is shown in FIG.
Driving is performed so that image information for one field is obtained for each cycle of the field shift gate pulse as shown in FIG. Then, the accumulation of the image charge in each photodiode 23 is started from, for example, the falling time of the accumulation start pulse and is performed until the rising time of the field shift gate pulse. That is, the period from the fall of the accumulation start pulse to the rise of the field shift gate pulse is the image light accumulation period. Therefore, in one field period, before the storage period, the image charges are swept without being stored. Further, the pixel charges accumulated in each pixel during the accumulation period are transferred after the accumulation period, that is, at the end of each field, and output to the outside.

Next, the operation of the frame-sequential color camera having the above structure will be described focusing on color balance adjustment and iris control. In FIG. 1, the image light from the subject 1 is imaged by the imaging lens 2 on the imaging surface of the solid-state imaging device 4. Based on the control signal from the synchronizing signal generation circuit 10, the image pickup device drive circuit 5 inputs a drive pulse to the solid-state image pickup device 4 at a predetermined field cycle to cause the solid-state image pickup device 4 to perform operations such as image sweeping, storage, and transfer. In this case, a control signal is also input from the synchronization signal generation circuit 10 to the color filter driving device 11, and the rotation of the color filter 3 and the scanning of the solid-state image sensor 4 are controlled to be synchronized.

Further, the rotation detector 13 detects the opaque regions 22 and 22a of the rotary color filter 3, and the information about the rotational position of the rotary color filter 3 is input to the synchronizing signal generating circuit 10. The synchronization signal generating circuit 10 detects the rotation position of the rotary color filter 3 and the solid-state image sensor 4 based on the signal from the rotation detector 13.
The period in which the color boundary of the rotary color filter 3 passes over the solid-state image sensor 4, that is, the color mixing period is detected from the position of the image pickup plane of FIG. The synchronization signal generation circuit 10 also inputs a signal indicating this color mixing period to the image pickup element drive circuit 5.

The image pickup device drive circuit 5 generates an accumulation start pulse in a period other than the color mixing period and inputs it to the solid-state image pickup device 4 based on the signal from the synchronization signal generation circuit 5, as will be described later in detail. As a result, the solid-state image sensor 4 outputs a signal corresponding to the image of the subject 1. The signal is amplified by the amplifier circuit 6 and then sample-held by the sample-hold circuit 7. The sampled and held signal is divided into R, G and B signals in the multiplexer circuit 8. The R, G, and B signals are output to the outside after being subjected to predetermined image processing by the signal processing circuit 12. The R, G, and B signals from the multiplexer circuit 8 are also input to the arithmetic unit 9 to generate a correction signal for white balance setting and iris control by arithmetic operation, as will be described later in detail, and perform synchronization. The signal is supplied to the signal generation circuit 10.

In such a frame-sequential color camera, the white balance is set in advance before the subject is imaged. To set the white balance, the image storage time of the solid-state image sensor 4 is set to an appropriate value in advance. When the white balance is set, a white subject such as white paper is photographed as the subject 1, or while the image of the white light source from the image generator (color viewer) is photographed.

First, the initial shutter time setting switch 17
By operating the electronic shutter time of the solid-state image sensor 4, that is, the image storage time, for example, 1/120 sec, 1/240.
Enter settings such as seconds in order. In response to this input, a control signal is input from the synchronization signal generation circuit 10 to the image pickup element drive circuit 5, and the image pickup element drive circuit 5 inputs a drive signal to the solid-state image pickup element 4 to control the image storage time of the solid-state image pickup element 4. To do.
In this case, the image storage time of each color R, G, B is controlled to be the time designated by the initial shutter time setting switch 17 while keeping the same value. The R, G, B image storage times can be controlled while maintaining a predetermined ratio.

In such a state, the image signal corresponding to the image of the white subject imaged by the solid-state image sensor 4 passes through the amplifier circuit 6, the sample hold circuit 7 and the multiplexer circuit 8 and is supplied to each of R, G and B. Color signals are input to the arithmetic unit 9. For example, when the signal amount of B is an appropriate light amount value, for example, 0.7 V, the arithmetic unit 9 outputs the appropriate light amount LE.
Turn on D16.

When the LED 16 is turned on, it is understood that the proper light quantity control for the color balance setting has been performed, and the operator next turns on the color balance setting switch 14. In response to this, the arithmetic unit 9 causes the solid-state imaging device 4 to
From the amplifier 6, the sample and hold circuit 7, and the multiplexer circuit 8, respectively, the signal level of each color of R, G, B, that is, the signal level of each color when the image storage time of the solid-state image sensor 4 is the same, Based on R, G, B
A correction signal for controlling the image storage time of each color required to make the image signals of the same level is obtained by calculation.

This correction signal is input to the image pickup element drive circuit 5 via the synchronization signal generation circuit 10. The image sensor driving circuit 5 sequentially generates the accumulation start pulse for each color after the color mixing period ends based on this correction signal, and the generation timing of this accumulation start pulse is the image accumulation time according to the color correction signal. The timing is adjusted so that the color balance is set.

The solid-state image pickup device 4 operates to sweep out the image charge until such an accumulation start pulse is input.
When input from, the image charge starts to be accumulated. This accumulation of image charge continues until the end of each field period,
The charges accumulated at the end of this period are transferred to the outside.
This makes it possible to change the image charge accumulation time for each color, control the sensitivity for each color, absorb the difference in the light source color temperature and the spectral transmittance of the color filter, and make the image signal of the white subject the same. It becomes possible to be a level.

When the desired subject is imaged after the color balance is set in this way, the present invention sets the image storage time for each color while maintaining the color balance set as described above. Adjust to perform iris control. That is, for example, in the case of a dark subject, while keeping the ratio of the image storage time of each color set as described above, the image storage time of each color is lengthened and the shutter time of each color is delayed to match the appropriate light amount. . In the case of a bright subject, the shutter time is shortened and the image accumulation time is shortened to match the appropriate light amount. In the iris control for adjusting to such an appropriate light amount, for example, an iris setting signal for exposure correction indicating the brightness level of the subject is calculated from the level of the image signal of each color input in the calculation device 9. This iris setting signal is input to the synchronization signal generation circuit 10, and a drive signal corresponding to the image sensor drive circuit 5 is input from the synchronization signal generation circuit 10 to adjust the image storage time of the image sensor 4. In this case, the image storage time is newly adjusted while maintaining the ratio of the image storage time of each color obtained by the color balance setting. by this,
The image storage time of the solid-state image sensor 4 is automatically adjusted according to the light amount of the subject, and the iris control is automatically performed.

It is also possible to perform iris adjustment by the manual aperture control unit 15. In this case, the arithmetic unit 9 is operated based on the aperture value input from the manual aperture control unit 15 or a signal indicating the electronic shutter time. The image storage time of each color of the solid-state image sensor 4 is controlled.
Also in this case, the image accumulation time for each color is set while maintaining the set color balance state. When the light amount is adjusted by the manual aperture control device 15, the light amount can be adjusted to an arbitrary amount regardless of the proper light amount.

FIG. 4 is a timing chart showing an operating state of the solid-state image pickup device 4 when the above operation is performed. The state of t0 shows a state in which the electronic shutter time of each color is set to 1/120 seconds by the initial shutter time setting switch 17. In this state, the shutter time T of each color, that is, the image charge storage time is the same. In addition, at the beginning of each field, there is a sweep-out period S including a color mixing period in which the color boundary of the color separation filter 3 passes over the image pickup surface of the solid-state image pickup device 4, and then the image accumulation time T for each color.
It is continuing. Further, such an image storing operation is continued until the end of each field period, and is transferred and output to the outside at the end of the field period (indicated by U in the figure).

The electronic shutter time is set by the initial shutter time setting switch 17 so that the appropriate light amount LED 16 is turned on as described above. Assuming that t0 in FIG. 4 is set to the proper light amount value, the color balance setting switch 14 is turned on next. In response to this, the arithmetic unit 9 adjusts the image charge accumulation time of each color so that the output levels of the image signals of each color become equal, as described above. In FIG. 4, t1 is the image charge accumulation time T1R, T1 of each color R, G, B in the state where the color balance is set in this way.
G and T1B are shown. Usually, B (blue) has the lowest sensitivity, and thus the accumulation time T1B of blue image light becomes the longest. Information indicating the image charge accumulation time of each color in the state where the color balance is set in this way is obtained by the synchronization signal generation circuit 1
0, the image pickup device driving circuit 5, or the arithmetic unit 9, and is held until the color balance is set again.

When the desired subject is imaged after the color balance is set in this way, the image charge accumulation time of the solid-state image sensor 4 is adjusted based on the iris setting signal as described above. This iris setting signal may be automatically obtained from the light level of the subject as described above,
Alternatively, it can be obtained based on the input information from the manual aperture control device 15. In any case, when controlling the image charge accumulation time of each color based on such an iris setting signal, the control is performed in a state where the ratio of each accumulation time obtained by the original color balance setting is maintained. FIG.
T2 indicates the state when a dark subject is imaged, for example, and the image charge accumulation time T2 of each color R, G, B in this case
The ratio of R, T2G and T2B keeps the ratio of the image charge accumulation times T1R, T1G and T1B when the color balance is set.

FIG. 5 shows an example of the electronic shutter time of the solid-state image pickup device 4 in each case of FIG. 4, that is, the image charge storage time. That is, at t0 in FIG. 4, the shutter time (T) of each color R, G, B set at the start-up by the initial shutter time setting switch 17 is 1/120 seconds. The signal amounts of the colors R, G, and B at this time are 1.4, 1.4, and 0.7, respectively.

By setting the color balance in such a state, the shutter times of R, G and B are set to 1/240, 1/240 and 1/120, respectively, as shown at t1. The image signal amount of each color obtained by this is 0.
7, the color balance is set.

Next, for example, when a dark subject is imaged, the signal amount of each color R, G, B is, for example, the signal amount when it is assumed that the color balance setting subject is imaged under the condition as shown by t1 '. It is assumed that the light amount is 0.5, 0.5, 0.5. In this case, at t2, the image charge accumulation time is 1/17 for R, G, and B, respectively.
By setting 0, 1/170, 1/90, it is possible to set an appropriate light amount while maintaining the color balance. In addition, the signal amounts of the respective colors R, G, and B at t2 are all 0.7.
Indicates the signal amount when it is assumed that a white paper or the like is imaged at such a light amount level, and the signal amount of each color actually changes depending on the object to be imaged. To do.

In the above embodiment, the initial shutter time setting switch 17 and the appropriate light amount LED are provided so that the proper light amount is manually set at the start-up for setting the color balance. It is also possible to remove the initial shutter time setting switch 17 and the appropriate light quantity LED 16 and automatically set a predetermined value as the initial shutter time. Further, even when the color balance is set, it is possible to automatically adjust the light amount level by using an image signal of one color or a plurality of colors when a color balance adjustment subject, for example, white paper is imaged in advance.

Further, in the above embodiments, the case where the image charge accumulation time of each color is set to the same time in advance before the color balance setting is described, but the image charge accumulation time of each color is set to a predetermined value. It is obvious that the ratio may be set to. In this case, the arithmetic unit 9 may generate the color balance correction signal in consideration of the predetermined ratio.

Furthermore, in addition to the iris control by the electronic shutter as described above, the image pickup element 2 is attached to the image pickup lens 2.
A diaphragm mechanism may be provided to adjust the amount of image light incident on. In this case, for example, at the time of startup before the color balance setting is performed, this diaphragm mechanism can be used to set the amount of light incident on the solid-state image sensor 4 to an appropriate amount of light. Further, in the case of a very bright or very dark subject that cannot be dealt with only by adjusting the electronic shutter, it is possible to cope with a wide range of subject light amount levels by using the aperture mechanism and the iris control by the electronic shutter together. It will be possible.

[0048]

As described above, according to the present invention, by adjusting the electronic shutter time of the solid-state image pickup device, it is possible to obtain an appropriate amount of light for various subjects. In this case, the auto iris mechanism around the lens and the circuit for driving the mechanism are not necessarily required, and the size and weight of the camera can be reduced. In addition, it is possible to avoid inconvenience such as camera position shift or focus shift due to manual adjustment of the iris ring of the image pickup lens, which facilitates image pickup operation and obtains a high-quality picked-up image. .

It is also possible to perform iris control over an extremely wide light amount range by using a diaphragm mechanism provided in a conventional image pickup lens in combination.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a frame sequential color camera equipped with an iris control device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a configuration of a color separation filter used in the color camera of FIG.

FIG. 3 is a schematic plan view (a) showing a configuration example of a solid-state image sensor used in the color camera of FIG. 1 and a schematic signal waveform diagram (b) showing control pulses supplied to the solid-state image sensor. ).

FIG. 4 is a signal waveform diagram for explaining an iris control operation in the color camera of FIG.

5 is an explanatory chart showing a signal amount and shutter time at each stage when iris control is performed in the color camera of FIG.

[Explanation of symbols]

 1 Subject 2 Imaging Lens 3 Color Separation Rotation Color Filter 4 Solid-state Imaging Device 5 Imaging Device Driving Circuit 6 Amplifier 7 Sample Hold Circuit 8 Multiplexer Circuit 9 Arithmetic Device 10 Synchronous Signal Generation Circuit 11 Filter Driving Device 12 Signal Processing Circuit 13 Rotation Detector 14 Color balance setting switch 15 Manual aperture controller 15 Proper light amount LED 17 Initial shutter time setting switch 18, 19, 20 Color filter area 21 Rotation axis 22, 22a Opaque area 23 Photodiode 24 Vertical transfer CCD 25 Horizontal transfer CCD 26 Amplifier

Claims (5)

[Claims] 1. A color filter for color-separating image light of an object received through an imaging lens; a solid-state image sensor capable of capturing image light color-separated by the color filter and capable of electronic shutter operation; An initial time setting unit that sets the image storage time of the solid-state image sensor corresponding to each color at the same time or at a predetermined time ratio when balance is set, and images the color balance adjustment subject after the setting by the initial time setting unit. Calculating means for obtaining a color balance correction signal based on the signal value of each color obtained from the solid-state image sensor, and adjusting the image accumulation time for each color of the solid-state image sensor based on the color balance correction signal. Shutter time setting means for setting the color balance by using the iris setting signal Based while keeping the set color balance condition, the iris control unit of the field sequential color camera, characterized by comprising the iris control means for adjusting each color image accumulation time, the. 2. The calculation means further obtains an iris setting signal necessary for obtaining an appropriate amount of light from the signal value of each color obtained from the solid-state image sensor, and the iris control means sets the setting based on the iris setting signal. The iris control device for a frame sequential color camera according to claim 1, wherein an appropriate exposure is automatically obtained by adjusting an image accumulation time of the solid-state image pickup device while maintaining the color balance. 3. A color balance set by the iris control means according to an iris setting signal obtained on the basis of the setting of the manual aperture control means. The iris control device for a frame sequential color camera according to claim 1, wherein the image storage time of the solid-state image sensor is controlled while maintaining the above. 4. An initial shutter time input means for setting the image storage time of each color to the same desired value, and a proper light amount display means for indicating that the image storage time is a proper value, 2. The frame sequential method according to claim 1, wherein the color balance is set after the proper light amount display means displays the proper light amount input state by adjusting the image storage time by the initial shutter time input means. Color camera iris controller. 5. The iris control device for a frame sequential color camera according to claim 1, further comprising a diaphragm mechanism for adjusting an incident light amount of subject image light in the imaging lens.