JP2000261813A - Digital camera - Google Patents

Abstract

(57) [Problem] To provide a digital camera capable of performing appropriate white balance adjustment according to a mode of the digital camera. SOLUTION: In the digital camera according to the present invention, a white balance adjusting circuit 202 performs recording at the time of recording.
The color temperature is detected based on the incident light incident through the diffuser filter existing in the optical path, the gain adjustment value is calculated based on the detected color temperature, and the white balance adjustment is performed on the image data. The color temperature is detected based on the incident light that does not pass through the diffuser filter, a gain adjustment value is calculated based on the detected color temperature, and white balance adjustment is performed on the image data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a digital camera, and more particularly, to a digital camera that changes a color temperature detection method at the time of white balance adjustment according to a mode.

[0002]

2. Description of the Related Art When shooting a subject that does not emit light by itself,
The color of a subject in a captured image depends on not only the reflection spectrum of the subject but also the color temperature (emission spectrum) of a light source illuminating the subject. For example, when the same white paper is imaged under outdoor sunlight, the image looks white, but when it is imaged with an indoor incandescent lamp, the image looks reddish.

However, when a person looks directly at a subject, the white paper looks white in each case because the eyes have color adaptation according to the illumination. Therefore, the camera needs to be corrected so that a white subject appears white regardless of the type of light source.
This correction is called white balance correction.

In order to correct the white balance, a white paper or the like is photographed before photographing, and the output ratio of R: G: B is 1: 1:
The gain may be adjusted to be 1. However, such correction is troublesome in a digital camera or the like in which shooting conditions change frequently, and therefore, an automatic white balance function capable of automatically correcting is required. Auto white balance methods include an external photometric method and an internal photometric method.

The external photometry method has a sensor for measuring the color temperature separately from the image pickup device, generates R and B gain control signals from the output signal, and adjusts the balance between R, G and B. On the other hand, in the internal photometry system, a correction signal is created using an image signal from an image sensor. This method utilizes a statistical property of an image that a signal in a wide area or a signal for a long time is often achromatic when integrated. Specifically, R
A gain control signal for R and B is generated from the signal obtained by integrating -Y and BY, and a feedback system is formed such that RY and BY become 0 irrespective of color temperature fluctuation.

Next, a conventionally proposed white balance adjustment method will be described. For example, Japanese Patent Application Laid-Open No. 6-1
In Japanese Patent Publication No. 21321 (imaging apparatus), an opaque translucent cover which is electrically opened and closed is mounted on the front of the taking lens, and when the imaging apparatus is turned on, an image is taken through the cover, and the level difference between the color signal levels is minimal. A technique is disclosed in which, after adjusting the amplification factors of the respective color signal components so as to obtain the following expression, the cover is opened and photographing is performed.

Japanese Patent Application Laid-Open No. Hei 5-34767 (a lens cap of a video camera) discloses a technique in which a liquid crystal sheet having a non-scattering mode is used, and the liquid crystal sheet is set to a non-scattering mode during photographing. ing.

Japanese Patent Application Laid-Open No. 7-79444 (still video camera) discloses a first and a second image sensing element and a color temperature measuring filter provided on the light receiving surface side of the first image sensing element so as to be able to advance and retreat. A white balance adjustment unit for performing white balance adjustment in accordance with an output signal from the first imaging element received through the color temperature filter; and driving an imaging lens with an output signal from the second imaging element. Focus control means for controlling the focus.

[0009]

However, in the technique described in Japanese Patent Application Laid-Open No. 6-121321, since the white balance is adjusted using the diffusion plate only when the power is turned on, illumination and the like are changed after the power is turned on. In such a case, there is a problem that the white balance cannot be correctly adjusted.

The technique disclosed in Japanese Patent Application Laid-Open No. Hei 5-34767 has no problem with accuracy, but has no means for detecting a change in illumination and the like, so that it cannot be adjusted again.

In the technique described in Japanese Patent Application Laid-Open No. 7-79444, since light is divided and white balance adjustment using an AF and a diffusion plate is performed at the same time, two CCDs are required and the cost increases. There is a problem.

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and it is an object of the present invention to provide a digital camera capable of appropriately adjusting a white balance according to a mode of the digital camera.

[0013]

According to a first aspect of the present invention, there is provided an image pickup device for converting a subject image formed through a lens system into image data, and a white balance adjusting device. First and second color temperature detecting means for performing color temperature detection by different methods, first color temperature detecting means during recording, and second color temperature detecting means during monitoring.
Selecting means for selecting the color temperature detecting means, gain adjusting means for adjusting the gain of the image data, and the color temperature of the first color temperature detecting means or the second color temperature detecting means selected by the selecting means. White balance control means for calculating a gain adjustment value based on the detection result and setting the gain adjustment value in the gain adjustment means to control white balance.

According to a second aspect of the present invention, an image pickup means for converting a subject image formed through a lens system into image data and a color temperature detection for white balance adjustment are performed by different methods. First and second color temperature detecting means for performing, a selecting means for selecting the first color temperature detecting means at the time of preparation for recording and recording, and a selecting means for selecting the second color temperature detecting means at the time of monitoring, and adjusting the gain of image data. And a gain adjustment value calculated based on a color temperature detection result of the first color temperature detection means or the second color temperature detection means selected by the selection means, and the gain adjustment value is set in the gain adjustment means. And white balance control means for controlling the white balance.

[0015] The invention described in claim 3 is based on claim 1.
Alternatively, in the invention according to claim 2, the first color temperature detecting means detects a color temperature based on incident light incident through a diffusion plate filter or a milky white filter existing in an optical path, and detects the second color temperature. The temperature detecting means detects a color temperature based on incident light that does not pass through a diffusion plate filter or a milky white filter.

The invention described in claim 4 is the first invention.
In the invention according to any one of Items 1 to 3, at the time of recording, first, an image is taken, image data is stored in a storage unit, and then color temperature detection is performed by the first color temperature detection unit. The white balance control means calculates a gain adjustment value based on the color temperature detection result of the first color temperature detection hand, sets the gain adjustment means, and sets the gain adjustment means for the image data stored in the storage means. The white balance is adjusted by using the white balance adjustment, and then the image is recorded on a recording medium.

The invention described in claim 5 is the third invention.
In the invention described in the above, further, an aperture provided with the diffusion plate filter or the milky white filter, and an aperture drive means for moving the aperture, and inserting and retracting the diffusion plate filter or the milky white filter into the optical path. It is provided.

The invention according to claim 6 is the same as the invention according to claim 3.
In the invention described in the above, further, a shutter provided with the diffusion plate filter or the milky white filter, and shutter driving means for driving the shutter to insert and retract the diffusion plate filter or the milky white filter into the optical path. It is provided.

The invention according to claim 7 is the first invention.
3. The liquid crystal panel according to claim 2, wherein the liquid crystal panel switches between a light scattering state and a transparent state according to the presence or absence of an electric field in the optical path, and a liquid crystal panel driven by applying an electric field to the liquid crystal panel. Driving means, wherein the first color temperature detecting means detects a color temperature based on incident light incident through a liquid crystal plate in a light scattering state, and the second color temperature detecting means comprises a transparent state. The color temperature is detected based on the incident light that enters through the liquid crystal plate.

The invention described in claim 8 is the same as the invention described in claim 7.
In the invention described in the above, at the time of the monitoring, if the amount of incident light or the gain adjustment value exceeds a predetermined value, the selection means selects the first color temperature detection means, and the white balance control means A gain adjustment value is calculated based on a color temperature detection result of the first color temperature detection means, and is set in the gain adjustment means to control a white balance.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a digital camera according to the present invention will be described below in detail with reference to the accompanying drawings.

(Embodiment 1) A digital camera according to Embodiment 1 will be described with reference to FIGS. FIG.
FIG. 2 is a block diagram illustrating a configuration of the digital camera according to the first embodiment. As shown in FIG. 1, the digital camera includes a lens system 100a, 100b, a shutter 101, and an aperture 10.
2, CCD 103, CDS circuit 104, AGC amplifier 1
05, A / D converter 106, signal processing unit 107,
Decompression unit 108, MCC 110, RAM 111, PC card interface 112, controller 121, display unit 122, operation unit 123, SG (control signal generation) unit 12
4, a lens drive circuit 125, a lens drive mechanism 126, a shutter drive circuit 127, a shutter drive mechanism 128, an aperture drive circuit 129, and an aperture drive mechanism 130. A detachable PC card 150 is connected via the PC card interface 112.

The lens systems 100a and 100b form a subject image on the CCD 103. Lens drive circuit 125
Drives the lens driving mechanism 126 in accordance with the control signal supplied from the controller 121, and
a, 100b are moved in the optical axis direction. The shutter drive circuit 127 drives the shutter drive mechanism 128 according to a control signal supplied from the controller 121 to control the opening and closing of the shutter 101.

The aperture 102 is for limiting the light amount of the subject. The aperture drive circuit 129 drives the aperture drive mechanism 130 according to a control signal supplied from the controller 121, and sets the aperture 102 to a desired aperture.

The CCD (Charge Coupled Device) 103 converts a subject image input through the lens systems 100a and 100b into an electric signal (analog image data). The CDS (correlated double sampling) circuit 104 is a circuit for reducing noise in the CCD type image pickup device.

The AGC amplifier 105 corrects the level of the signal correlated double-sampled by the CDS circuit 104. Further, the A / D converter 106 is connected to the AGC amplifier 1
The analog image data input from the CCD 103 via the input device 05 is converted into digital image data. That is, C
The output signal of the CD 103 is supplied to the CDS circuit 104 and the AG
The signal is converted into a digital signal at an optimum sampling frequency (for example, an integer multiple of the subcarrier frequency of the NTSC signal) by the A / D converter 105 via the C amplifier 105.

The signal processing unit 107 performs signal processing on input image data. Compression / expansion unit 1
08 performs image compression / decompression. For example, J
Performs PEG-compliant image compression and decompression.

MCC (Memory Card Controller) 110
, Temporarily stores the compressed image and records the image on the PC card 150 via the PC card interface 112 or reads out the image from the PC card 150.

The controller 121 uses the RAM as a work area in accordance with a program stored in the ROM, and controls all operations inside the digital camera in accordance with an instruction from the operation unit 123 or an external operation instruction such as a remote controller (not shown). I do. Specifically, the controller 121
Controls an imaging operation, an automatic exposure (AE) operation, an automatic white balance (AWB) adjustment operation, an AF operation, and the like.

The display unit 122 is implemented by an LCD, an LED, an EL, or the like, and displays captured digital image data, decompressed recorded image data, and the like. Operation unit 1
Reference numeral 23 includes a release key for instructing shooting (recording) and buttons for externally performing function selection and other various settings.

The digital camera 100 (controller 121) described above is a recording mode in which image data obtained by imaging a subject is recorded on the PC card 150, and image data obtained by imaging the subject is directly displayed on the display unit 122. It has a monitoring mode.

FIG. 2 is a diagram showing a specific configuration example of the signal processing circuit 107 shown in FIG. The signal processing unit 107
As shown in FIG. 2, a color separation circuit 201 for performing color separation and a white balance adjustment circuit 20 for performing white balance adjustment
2. Matrix circuit 20 for separating a luminance signal and a color difference signal
3, and a video signal processing unit 20 for generating a video signal
4 is included. The white balance adjustment circuit 20
Reference numeral 2 denotes a color temperature detection unit 211 that detects a color temperature, calculates a gain adjustment value (white balance adjustment value) based on the color temperature detection result of the color temperature detection unit 211, and uses the calculated gain adjustment value as a gain adjustment circuit. Color temperature control unit 21 set to 210
2, and a gain adjustment circuit 2 for adjusting the gain of image data
10 is included.

In the signal processing circuit 107 having the above configuration, the color separation circuit 201 separates the input image data into R, G, and B, and converts the RGB signals into white balance adjustment circuits 202.
Output to In the white balance adjustment circuit 202, the color temperature detection circuit 211 detects the color temperature of the RGB signal input from the color separation circuit 105. Color temperature controller 212
Is based on the color temperature detection result of the color temperature detection unit 211,
The gain adjustment values of the signal and the B signal are respectively calculated, and the gain adjustment values of the R signal and the B signal are set in the gain adjustment circuit 210.

In the gain adjustment circuit 210, the input RG
Of the B signals, the R signal and the B signal are subjected to gain adjustment according to the gain adjustment value set by the color / color temperature control unit 212, and the gain-adjusted RGB signals are output. The matrix circuit 107 converts the input RGB signals into a luminance signal Y and color difference signals Cr and Cb, and outputs the signals. In the video signal processing unit 204, the input luminance signal Y and color difference signal Cr,
Cb is converted into a video signal and output.

FIG. 3 shows an example 1 of the configuration of the stop 102 shown in FIG.
It is a figure showing (slider type). FIG. 4 is a diagram showing a configuration example 2 (rotary type) of the diaphragm 102 in FIG.

The stop 102 shown in FIG. 3 has a slider type structure, and the stop plate 300 has a substantially rectangular shape and is provided with openings 302 to 304 having different sizes. The aperture plate 300 is provided with a diffusion plate filter 301 that covers the opening. A rack 305 meshing with the drive gear 306 of the aperture drive mechanism 130 is formed below the aperture plate 300. In the above-described configuration, the drive gear 306 of the drive stop drive mechanism 130 is driven and rotated by the stop drive circuit 129, and the slider-type stop plate 300 slides according to the rotation direction. That is, the diaphragm driving circuit 129 slides the diaphragm plate 300 in accordance with the control signal of the controller 121, and arranges any of the openings 302 to 304 of the diaphragm plate 300 and the diffusion plate filter 301 in the optical path.

The stop 102 shown in FIG. 4 is of a rotary type, and the stop plate 400 has a circular shape and is rotatably supported by a support member 410. Aperture plate 400
Are provided with openings 402 to 404 having different sizes, and a diffusion plate filter 401 for covering the openings is provided. The diaphragm driving mechanism 1 is provided on the diaphragm plate 400.
A rack meshing with the 30 drive gears 411 is formed. In the above configuration, the drive gear 411 of the aperture drive mechanism 130 is driven and rotated by the aperture drive circuit 129,
In response to this, the aperture plate 400 rotates. That is, the aperture driving circuit 129 rotates the aperture plate 400 according to the control signal of the controller 121, and arranges any of the openings 402 to 403 of the aperture plate 400 and the diffusion plate filter 401 in the optical path.

Next, the operation relating to the white balance adjustment of the digital camera having the above configuration will be described separately for the monitoring mode and the recording mode. First, the monitoring mode will be described. In FIG. 1, first, when the monitoring mode is selected by operating the operation unit 123, the controller 121 executes the monitoring mode. Specifically, first, the aperture driving circuit 13
Reference numeral 0 indicates that the aperture driving mechanism 130 is driven based on a control signal from the controller 121 so that a desired opening of the aperture 102 is disposed in the optical path, and is disposed in front of the CCD 103.

Under the control of the controller 121, image data corresponding to the subject image incident through the apertures of the lens systems 101a and 101b and the aperture 102 is converted into C data.
The CDS is read from the CD 103 and then the CDS circuit 104
Then, the image data whose gain has been adjusted by the AGC amplifier 105 is converted into digital image data by the A / D converter 106 and input to the signal processing unit 107.
Then, after the digital image data is color-separated by the signal processing unit 107, it is converted into a luminance signal and a color difference signal,
It is further converted to a video signal and displayed on the display unit 122.

The white balance adjustment in the monitoring mode will be described. In this monitoring mode,
The white balance is adjusted by the internal metering method. In this case, the internal photometry method is a full-screen averaging method that uses the assumption that the color components of the surface are mixed to produce an achromatic color, or a white part extraction method that detects white parts in the screen and adjusts the white balance Can be used.

Specifically, the white balance adjustment circuit 2
In 02 (see FIG. 2), the color temperature of the RGB signal input from the color separation circuit 201 is detected by the color temperature detection unit 211. Then, based on the color temperature detection result of the color temperature detection unit 211, the R signal and the B signal are output by the color temperature control unit 212.
The gain adjustment value of the signal is calculated, and the gain adjustment circuit 106
Are set to gain adjustment values of the R signal and the B signal. In the gain adjustment circuit 210, the R signal and the B signal among the input RGB signals are subjected to gain adjustment according to the gain adjustment value set by the color temperature control unit 212, and the white balance adjusted RGB signals are adjusted. Is output. This white balance adjustment is performed continuously during monitoring.

Next, the operation in the recording mode will be described. When the release key is pressed, the controller 121 executes the recording mode. When this recording mode is selected, first, a setting operation of a gain adjustment value for white balance adjustment is performed. In FIG. 1, first, the aperture driving circuit 129 drives the aperture driving mechanism 130 based on a control signal from the controller 121 to arrange the diffusion plate filter of the aperture 102 in the optical path, and arranges it in front of the CCD 103. Then, under the control of the controller 121, image data corresponding to the light image incident through the lens systems 101a and 101b and the diffuser filter of the aperture 102 is read from the CCD 103, noise is reduced by the CDS circuit 104, and AGC is performed. The image data whose gain has been adjusted by the amplifier 105 is converted into digital image data by the A / D converter 106 and input to the signal processing unit 107.

In the signal processing unit 107, the color separation circuit 201
The RGB signals obtained by separating the input image data into R, G, and B are
2 is input. In the white balance adjustment circuit 202, the color temperature of the RGB signal input from the color separation circuit 105 is detected by the color temperature detection unit 211. And
Based on the color temperature detection result of the color temperature detection unit 211, the color temperature control unit 212 calculates the gain adjustment values of the R signal and the B signal such that the levels of the R, G, and B signals become minimum values, respectively. The gain adjustment values of the R signal and the B signal of the gain adjustment circuit 210 are set.

When the setting of the gain adjustment value for the white balance adjustment is completed, the aperture driving circuit 129
Based on a control signal from the controller 121, the diaphragm driving mechanism 130 is driven to retract the diffusion plate filter of the diaphragm 102 from the optical path, and an aperture corresponding to the set aperture value is arranged in the optical path. Placed in front of the Then, under the control of the controller 121, image data corresponding to the subject image that enters through the apertures of the lens systems 100 a and 100 b and the aperture 102 is transferred to the CCD 103.
, And the image data subjected to noise reduction by the CDS circuit 104 and gain-adjusted by the AGC amplifier 105 is converted into digital image data by the A / D converter 106 and input to the signal processing unit 107. .

In the signal processing unit 107 (see FIG. 2), the color separation circuit 201 converts the digital image data into RGB data.
After color separation into signals, the white balance adjustment circuit 20
In 2, the R signal and the B signal of the input RGB signals are subjected to gain adjustment according to the gain adjustment value set as described above, and the RGB signals subjected to white balance adjustment are output. Then, the white balance adjusted RG
The B signal is converted into a luminance signal and a chrominance signal by a matrix circuit 203, and then compressed by a compression / expansion unit 108. The compressed image data is recorded on a PC card 150 via an MCC 110. .

That is, in the recording mode, the white balance is adjusted by using the light incident from the diffuser filter, so that the white balance is not affected by the color of the clothes of the person to be the subject, the color of the background, and the illumination. White balance can be maintained.

As described above, in the first embodiment, during monitoring, white balance adjustment is performed based on normal image data that does not pass through a diffusion plate filter. Prior to recording, a gain adjustment value is calculated and set using light passing through a diffuser filter, and then image data is captured and white balance-adjusted image data is adjusted to a PC card 150 with an appropriate gain adjustment value. Since recording was performed, that is, white balance adjustment during monitoring was performed in a manner that did not interrupt image capture, even if the accuracy was somewhat rough, while white balance adjustment during recording was Even if you stop importing images,
Since the determination is performed with a more accurate method, the monitoring is not interrupted at the time of monitoring, the accurate white balance can be adjusted at the time of recording, and the white balance adjustment suitable for the mode can be performed.

In the first embodiment, the diffuser filter used for white balance adjustment is
Since the diffusion plate filter provided in the aperture is used, highly accurate color temperature detection is possible with a compact configuration.

In the first embodiment, the configuration is such that a diffusion plate filter is provided in the stop. However, the present invention is not limited to this, and a white milky color filter is used in the stop instead of the diffusion plate filter. The white balance adjustment in the recording mode may be performed based on the light passing through the white milky color filter.

(Embodiment 2) A digital camera according to Embodiment 2 will be described with reference to FIG. FIG. 5 is a flowchart illustrating a white balance adjustment operation according to the second embodiment. The configuration of the digital camera according to the second embodiment can be realized by the same configuration as that of the first embodiment. In the second embodiment, in the recording mode, first, before adjusting the white balance of the captured image data, the R
The image data stored in the RAM 111 is stored in the AM 111, and then the imaging for calculating the gain adjustment value is performed to calculate the gain adjustment value. Based on the calculated gain adjustment value, the image data stored in the RAM 111 is subjected to white balance adjustment. , And then stored in the PC card 150. Hereinafter, a specific description will be given.

In FIG. 5, when the release key is pressed, the controller 121 executes the recording mode. First, the AF process and the AE process are executed under the control of the controller 121 (step S100). AF
The processing / AE processing is a well-known processing, and a detailed description thereof will be omitted here. Next, an imaging operation is started (step S101), and under the control of the controller 121,
In the CCD 103, the aperture 1 corresponding to the set aperture value
The image data corresponding to the subject image incident through the opening 02 is read out, the noise is reduced by the CDS circuit 104, and the image data gain-adjusted by the AGC amplifier 105 is converted into an A / D converter 106. Is converted into digital image data and input to the signal processing unit 107. In the signal processing unit 107, the image data is separated into R, G, and B by the color separation circuit 201 and stored in the RAM 111 (step S102).

Next, the aperture driving circuit 129 is controlled by the aperture driving mechanism 13 based on a control signal from the controller 121.
0 is driven to dispose the diffusion plate filter of the diaphragm 102 in the optical path and disposed in front of the CCD 103 (step S1).
03). Then, data sampling for calculating the gain adjustment value is performed (step S104). Specifically, under the control of the controller 121, image data corresponding to the light image incident through the diffuser filter is transferred to the CCD 1
The image data read from the C.O. 03 and subjected to noise reduction by the CDS circuit 104 and gain-adjusted by the AGC amplifier 105 are converted into digital image data by the A / D converter 106 and input to the signal processing unit 107. .

In the signal processing unit 107, the signal processing unit 107
The RGB signal obtained by separating the input image data into R, G, and B by the color separation circuit 201 is input to the white balance adjustment circuit 202. In the white balance adjustment circuit 202, the color temperature detection unit 211
The color temperature of the RGB signal input from the color separation circuit 105 is detected. Then, based on the color temperature detection result of the color temperature detection unit 211, the R, G, B
Signal and B such that the level of each signal of
The gain adjustment values of the signals are calculated, and the gain adjustment circuit 106
The gain adjustment values of the R and B signals are set (step S105).

When the setting operation of the gain adjustment value is completed, the image data imaged as described above and stored in the RAM 111 is read out, and the white balance adjustment circuit 2
In step 02, the R signal and the B signal of the input image data are subjected to gain adjustment according to the gain adjustment value set as described above, and the RGB signals subjected to white balance adjustment are output (step S106). . Then, the image data subjected to the white balance adjustment is supplied to the matrix circuit 203.
After being converted into a luminance signal and a chrominance signal, the image data subjected to compression processing by the compression / decompression unit 108 and subjected to compression processing is
The data is recorded on the PC card 150 via the MCC 110 (step S107). Then, the aperture driving circuit 129
Drives the diaphragm driving mechanism 130 based on a control signal from the controller 121 to retract the diffusion plate filter of the diaphragm 102 from the optical path.

In the second embodiment, the white balance adjustment in the monitoring mode is performed in the same manner as in the first embodiment, and the description thereof is omitted.

As described above, in the second embodiment, in the recording mode, first, before adjusting the white balance of the captured image data, the RAM 11
11 and then perform imaging for calculating a gain adjustment value, calculate a gain adjustment value, and perform white balance adjustment on the image data stored in the RAM 111 based on the calculated gain adjustment value. , Then PC Card 1
Since the image data is stored at 50, sampling can be avoided for white balance adjustment before photographing, and a shutter chance can be prevented from being missed.

(Embodiment 3) A digital camera according to Embodiment 3 will be described. The configuration of the digital camera according to the third embodiment can be realized by the same configuration as the first embodiment. In the third embodiment, when preparing for photographing (immediately after turning on the power, immediately after switching to the photographing mode, immediately after opening the lens barrier, etc.),
The white balance is adjusted based on the light passing through the diffusion plate.

First, at the time of photographing preparation (immediately after turning on the power, immediately after switching to the photographing mode, immediately after opening the lens barrier, etc.), first, a gain adjustment value (white balance adjustment value) for white balance adjustment is set. A setting operation is performed. In FIG. 1, first, the aperture driving circuit 129 drives the aperture driving mechanism 130 based on a control signal from the controller 121 to arrange the diffusion plate filter of the aperture 102 in the optical path, and arranges it in front of the CCD 103. The lens systems 101a and 101b are controlled by the controller 121.
And image data corresponding to the light image incident through the diffusion plate filter of the aperture 102 is read from the CCD 103,
The image data whose noise has been reduced by the CDS circuit 104 and the gain of which has been adjusted by the AGC amplifier 105 is converted into digital image data by the A / D converter 106 and converted into digital image data.
7 is input.

In the signal processing unit 107, the color separation circuit 201
The RGB signals obtained by separating the input image data into R, G, and B are
2 is input. In the white balance adjustment circuit 202, the color temperature of the RGB signal input from the color separation circuit 105 is detected by the color temperature detection unit 211. And
Based on the color temperature detection result of the color temperature detection unit 211, the color temperature control unit 212 calculates the gain adjustment values of the R signal and the B signal such that the levels of the R, G, and B signals become minimum values, respectively. The gain adjustment values of the R signal and the B signal of the gain adjustment circuit 106 are set.

When the white balance operation is completed, the aperture driving circuit 129 drives the aperture driving mechanism 130 based on the control signal from the controller 121 to retract the diffusion plate filter of the aperture 102 from the optical path.

When the monitoring mode is selected, the controller 121 executes the monitoring mode. Specifically, first, the aperture drive circuit 130 drives the aperture drive mechanism 130 based on a control signal from the controller 121 to arrange a desired opening of the aperture 102 in the optical path, and arranges the aperture in front of the CCD 103.

Under the control of the controller 121, the image data corresponding to the subject image which enters through the apertures of the lens systems 101a and 101b and the aperture 102 is converted into C data.
The CDS is read from the CD 103 and then the CDS circuit 104
Then, the image data whose gain has been adjusted by the AGC amplifier 105 is converted into digital image data by the A / D converter 106 and input to the signal processing unit 107.
Then, the digital image data is color-separated by the color separation circuit 201 in the signal processing unit 107, and white balance adjustment based on the gain adjustment value set in the white balance adjustment operation is performed by the white balance adjustment circuit 202. Done. And the matrix circuit 203
Then, after being converted into a luminance signal and a color difference signal, the video signal is further converted into a video signal by the video signal processing unit 204 and the display unit 1
22 is displayed.

When the release key is pressed, the controller 121 executes the recording mode. Specifically, first, the aperture driving circuit 130
The diaphragm driving mechanism 130 is driven based on the control signal from the control unit 1 to place a desired opening of the diaphragm 102 in the optical path.
It is arranged in front of the CD 103.

Then, under the control of the controller 121, image data corresponding to the subject image incident through the apertures of the lens systems 101a and 101b and the aperture 102 is converted into C data.
The CDS is read from the CD 103 and then the CDS circuit 104
Then, the image data whose gain has been adjusted by the AGC amplifier 105 is converted into digital image data by the A / D converter 106 and input to the signal processing unit 107.
Then, the digital image data is color-separated by the color separation circuit 201 in the signal processing unit 107, and white balance adjustment based on the gain adjustment value set in the white balance adjustment operation is performed by the white balance adjustment circuit 202. Done. Then, the RGB signals whose white balance has been adjusted are output. Then, the RGB signals whose white balance has been adjusted are output from the matrix circuit 203 by the matrix circuit 203.
After being converted into a luminance signal and a color difference signal, the compression / decompression unit 10
8, the compressed image data is MC
It is recorded on the PC card 150 via C110.

As described above, in the third embodiment, at the time of preparation for photographing (immediately after turning on the power, immediately after switching to the photographing mode, immediately after opening the lens barrier, etc.), the incident light passing through the diffuser filter is Based on the color temperature, the gain adjustment value is calculated based on the color temperature, and the white balance is adjusted.Therefore, the color temperature can be detected by an accurate method during the shooting preparation stage, and the white balance adjustment during monitoring is performed with high accuracy Can be performed.

(Embodiment 4) A digital camera according to Embodiment 4 will be described with reference to FIGS. In the first to third embodiments, the stop 102
Embodiment 4 has a configuration in which a diffusion plate filter is provided.
In this embodiment, the shutter 101 is provided with a diffuser filter. FIG. 6 is a diagram illustrating a configuration of a shutter 101 according to the fourth embodiment.

In the shutter 101 shown in FIG. 6, an opening is formed in the shutter blade 500, and the opening is covered with the diffusion plate filter 501. The shutter blade 500 is fixed to a rotating member (aperture driving mechanism) 510, and the rotating member 510 is driven to rotate by a shutter driving circuit 127. Therefore, when the rotating member 510 is rotated by the shutter driving circuit 127, the shutter blade 500 rotates accordingly. That is, the shutter drive circuit 127 responds to the control signal of the controller 121 by
By rotating the rotating member 510, the diffusion plate filter 501 of the shutter blade 500 is arranged in the optical path.

FIG. 7 is an explanatory diagram for explaining the position of the shutter blade 500. As shown in FIG. FIG. 7A shows a case where the shutter is closed, and FIG. 7B shows a case where the diffuser filter 501 of the shutter is arranged in the optical path.

When white balance is adjusted by light passing through the diffuser filter, the diffuser filter provided in the shutter 101 having the above-described structure is replaced with the diffuser filter provided in the diaphragm 102 described in the first embodiment. Alternatively, the diffusion plate filter 501 provided on the shutter 101 may be used.
Is placed in the optical path.

As described above, in the fourth embodiment, a diffuser filter provided in a shutter is used as a diffuser filter used for white balance adjustment. Accurate color temperature detection becomes possible.

In the first embodiment, the shutter is provided with the diffuser filter, but the present invention is not limited to this. Instead of the diffuser filter, the present invention is not limited thereto.
The shutter may be provided with a white milky color filter and used instead of the diffusion plate filter.

(Embodiment 5) Embodiment 5 will be described with reference to FIGS.
This will be described with reference to FIG. FIG. 8 is a diagram illustrating a configuration of a digital camera according to the fifth embodiment. Embodiment 1
Portions having the same configuration and function as those described above are denoted by the same reference numerals, and description thereof will be omitted. Embodiment 5 is Embodiment 1
The difference is that a liquid crystal panel 200 and a liquid crystal panel drive circuit 201 are provided. In the first to fourth embodiments, the example in which the color temperature is detected using the diffusion plate filter has been described. In the fifth embodiment, a liquid crystal plate is used instead of the diffusion plate filter.
The color temperature is detected based on the incident light when the liquid crystal plate is in the light scattering state.

In FIG. 8, the liquid crystal plate 200 is a CCD 1
The switching between the transparent state and the light-scattering state is performed in accordance with the voltage applied to the liquid crystal panel drive circuit 201. As the liquid crystal plate 200, for example, a polymer dispersed liquid crystal plate can be used. The liquid crystal panel driving circuit 201 controls the liquid crystal panel 20 according to a control signal transmitted from the controller 121.
This is a drive circuit for switching the transparent state and the light scattering state of the liquid crystal plate by applying an applied voltage to 0.

FIGS. 9 and 10 are diagrams for explaining the scattering state of the liquid crystal plate 200. FIG. 9 shows the case where the liquid crystal plate 200 is in the transparent state, and FIG. 9 shows the case where the liquid crystal plate 200 is in the light scattering state. Is shown. When an electric field is applied to the liquid crystal panel 200 by the liquid crystal panel drive circuit 201, as shown in FIG. 9, the liquid crystal molecules are aligned in the direction of the electric field and the incident light goes straight without scattering (transparent state). . On the other hand, the liquid crystal panel drive circuit 20
According to 1, when no electric field is applied to the liquid crystal plate 200, as shown in FIG. 10, the direction of the liquid crystal molecules is disordered, and the incident light is scattered (light scattering state). 11 and 12 are views showing the configuration around the liquid crystal plate 200 of the digital camera in FIG. 8. FIG. 11 shows a case where the liquid crystal plate 200 is in a transparent state, and FIG. Show the case.

In the first to fourth embodiments, the color temperature is detected based on the incident light passing through the diffuser filter.
In the fifth embodiment, when the liquid crystal plate 200 is in the light scattering state, the color temperature is detected based on the light incident from the liquid crystal plate. Specifically, during data sampling for white balance adjustment at the time of recording (see Embodiment 1) or at the time of preparation for photographing (see Embodiment 3), the liquid crystal plate 200 is set to the light scattering state to set the white balance. The adjustment data is sampled, and in other cases, the liquid crystal plate 200 is made transparent.

In the monitoring mode, when the color temperature changes more than a predetermined value or the amount of light changes more than a predetermined amount when the color temperature is detected by the internal photometry method, the liquid crystal plate 200 is temporarily stopped. In a light scattering state, color temperature detection for white balance adjustment may be performed. 13A and 13B are diagrams showing the driving timing of the liquid crystal panel during monitoring. FIG. 13A shows the ON / OFF timing of the timing of the electronic shutter, and FIG. 13B shows the state of the liquid crystal panel. FIG. At the time of monitoring, if the color temperature detected by the internal photometry method or the amount of incident light exceeds a predetermined value, as shown in FIG. Yes) and the white balance adjustment circuit 2
The color temperature is detected by the color temperature detector 211 of FIG. In this case, since the liquid crystal panel 200 is opaque only during the capture of one frame, there is almost no effect on monitoring.

Then, as described above, the color temperature control unit 2
12, based on the color temperature detection result of the color temperature detection unit 211, the gain adjustment values of the R signal and the B signal that minimize the level difference between the R, G, and B signals are calculated, and the gain adjustment circuit The gain adjustment values of the R signal and the B signal of 210 are set. Then, the gain adjustment circuit 210 performs white balance adjustment based on the set gain adjustment value.

As described above, in the fifth embodiment, when the white balance is adjusted, the liquid crystal plate is sampled in the light scattering state, so that the configuration of the digital camera can be made compact.

In the monitoring mode, when the color temperature changes more than a predetermined value by the color temperature detection by the internal photometry method or when the light amount changes more than a predetermined amount, the liquid crystal plate is set to the light scattering state. Since color temperature detection for white balance adjustment is performed, accurate white balance adjustment can be performed even during monitoring.

The present invention is not limited to the above-described embodiment, but can be appropriately changed without changing the gist of the invention.

[0081]

As described above, according to the first aspect of the present invention, the first and second color temperature detecting means for detecting the color temperature for white balance adjustment by different methods are provided. During recording, the first color temperature detecting means
At the time of monitoring, the second color temperature detecting means is selected, and a gain adjustment value is calculated based on the selected color temperature detection result of the first color temperature detecting means or the second color temperature detecting means, and is set as the gain adjusting means. Since the white balance of the image data is controlled, appropriate white balance adjustment according to the mode can be performed.

According to the second aspect of the present invention, there are provided first and second color temperature detecting means for performing color temperature detection for white balance adjustment by different methods.
The first color temperature detecting means is used during preparation for recording and recording.
At the time of monitoring, the second color temperature detecting means is selected, and a gain adjustment value is calculated based on the selected color temperature detection result of the first color temperature detecting means or the second color temperature detecting means, and is set as the gain adjusting means. Then, the white balance of the image data is controlled, so that appropriate white balance adjustment according to the mode can be performed.

According to the third aspect of the present invention, in the first or second aspect of the present invention, the first color temperature detecting means is provided via a diffusion plate or a milky white filter existing in the optical path. The color temperature is detected based on the incident light, and the second color temperature detecting means detects the color temperature based on the incident light that does not pass through the diffuser filter or the milky white filter. In addition to the effects of the invention described in 2, the white balance can be accurately adjusted at the time of recording, and the white balance can be adjusted without interrupting the monitoring at the time of monitoring.

According to the invention described in claim 4, in the invention described in any one of claims 1 to 3, at the time of recording, first, an image is taken and the image data is stored in the storage means. The color temperature is detected by the first color temperature detecting means, and a gain adjustment value is calculated based on the color temperature detection result of the first color temperature detecting hand, and the gain adjusting means is set. The image data stored in the means is subjected to white balance adjustment and then recorded on a recording medium. Therefore, in addition to the effects of the invention according to claims 1 to 3, imaging for recording is performed. Since the color temperature detection for adjusting the white balance is not performed before the photographing, it is possible to prevent a shutter chance from being missed.

According to a fifth aspect of the present invention, in the third aspect of the present invention, there is further provided an aperture provided with a diffusion plate filter or a milky white filter; Since the diaphragm driving means for inserting and retracting into the optical path is provided, in addition to the effect of the invention described in claim 3, high-precision white balance adjustment is possible with a space-saving and simple configuration. .

According to a sixth aspect of the present invention, in the third aspect of the present invention, a shutter provided with a diffusion plate filter or a milky white filter, and the shutter is driven to form a diffusion plate filter or a milky white filter. Since the shutter driving means for inserting and retracting the filter into and out of the optical path is provided, in addition to the effect of the invention described in claim 6, it is possible to perform white balance adjustment with high accuracy with a space-saving and simple configuration. Become.

Further, according to the invention described in claim 7, in the invention described in claim 1 or claim 2,
A first color temperature detecting means, comprising, in an optical path, a liquid crystal plate that switches between a light scattering state and a transparent state depending on whether an electric field is applied, and a liquid crystal plate driving unit that drives the liquid crystal plate by applying an electric field; Performs color temperature detection based on incident light that enters through a liquid crystal plate in a light scattering state, and the second color temperature detection unit includes:
Since the color temperature is detected based on the incident light that enters through the liquid crystal plate in the transparent state, in addition to the effects of the invention described in claim 1 or 2, the space temperature is reduced and the configuration is simplified. Accurate white balance adjustment becomes possible.

According to the invention described in claim 8, in the invention described in claim 7, when the amount of incident light or the gain adjustment value exceeds a predetermined value during monitoring,
Since the gain adjustment value is calculated based on the color temperature detection result of the first color temperature detection means and the gain adjustment means is set to control the white balance, in addition to the effect of the invention according to claim 7, In addition, high-precision white balance adjustment is possible even during monitoring.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a digital camera according to a first embodiment.

FIG. 2 is a diagram illustrating a specific configuration example of a signal processing unit in FIG. 1;

FIG. 3 is a diagram showing a configuration example 1 (slider type) of the diaphragm in FIG. 1;

FIG. 4 is a diagram showing a configuration example 2 (rotary type) of the stop shown in FIG. 1;

FIG. 5 is a flowchart illustrating a white balance adjustment operation according to the second embodiment.

FIG. 6 is a diagram illustrating a configuration of a shutter according to a fourth embodiment.

FIG. 7 is an explanatory diagram for explaining a position of a shutter blade.

FIG. 8 is a diagram showing a configuration of a digital camera according to a fifth embodiment.

FIG. 9 is an explanatory diagram for explaining a non-scattering state (transparent state) of the liquid crystal plate of FIG. 8;

FIG. 10 is an explanatory diagram for explaining a scattering state of the liquid crystal plate of FIG. 8;

11 is a diagram illustrating a configuration around a liquid crystal plate of the digital camera in FIG. 8;

FIG. 12 is a diagram illustrating a configuration around a liquid crystal plate of the digital camera in FIG. 8;

FIG. 13 is a diagram showing the drive timing of the liquid crystal plate during monitoring.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 lens system 101 shutter 102 aperture 103 CCD (charge coupled device) 104 CDS (correlated double sampling) circuit 105 variable gain amplifier (AGC amplifier) 106 A / D converter 107 signal processing unit 108 compression / expansion unit 110 MCC (Memory) Card Controller) 111 RAM (internal memory) 112 PC card interface 121 Controller 122 Display unit 123 Operation unit 125 Lens drive circuit 126 Lens drive mechanism 127 Shutter drive circuit 128 Shutter drive mechanism 129 Aperture drive circuit 130 Aperture drive mechanism 150 PC card 200 Aperture Board 201 Color separation circuit 202 White balance adjustment circuit 203 Matrix circuit 204 Video signal processing unit 210 Gain adjustment circuit 211 Color temperature detection unit 212 Color temperature control unit 300 Aperture plate 01 diffuser filter 302-304 openings 305 rack 306 driven gear 400 stop plate 401 diffusing plate filter 402-404 opening 410 support member 411 driving gear 500 shutter blade 501 diffuser filter 510 rotating member

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 9/73 H04N 9/73 A 5C066 F term (Reference) 2H002 CC01 CC21 DB17 EB17 FB01 FB39 GA33 JA07 2H042 BA08 BA16 2H048 AA01 AA06 AA18 AA25 AA26 2H054 AA01 5C065 AA01 BB02 BB04 BB07 BB08 BB11 BB15 CC01 DD02 EE13 EE15 EE20 FF02 GG12 GG15 GG18 GG30 GG31 5C066 AA01 BA20 CA17 EA04 GM01 EA04 GM04

Claims (8)

[Claims] 1. An image pickup means for converting a subject image formed via a lens system into image data, and first and second color temperatures for performing color temperature detection for white balance adjustment by different methods from each other. Detecting means; selecting means for selecting the first color temperature detecting means at the time of recording; selecting means for selecting the second color temperature detecting means at the time of monitoring; gain adjusting means for adjusting the gain of image data; A white balance control unit that calculates a gain adjustment value based on the color temperature detection result of the first color temperature detection unit or the second color temperature detection unit, sets the gain adjustment value in the gain adjustment unit, and controls a white balance. A digital camera, comprising: 2. An image pickup means for converting a subject image formed through a lens system into image data, and first and second color temperatures for detecting a color temperature for white balance adjustment by different methods. Detecting means and first color temperature detecting means at the time of preparation for recording and recording.
Selecting means for selecting the second color temperature detecting means at the time of monitoring; gain adjusting means for adjusting the gain of the image data; and the first color temperature detecting means or the second color temperature detecting means selected by the selecting means White balance control means for calculating a gain adjustment value based on the color temperature detection result of the means and setting the gain adjustment means to control the white balance; 3. The first color temperature detecting means detects a color temperature based on incident light incident through a diffusion plate filter or a milky white filter existing in an optical path, and the second color temperature detecting means includes: 3. The digital camera according to claim 1, wherein a color temperature is detected based on incident light that does not pass through a diffusion plate filter or a milky white filter. 4. At the time of the recording, first, an image is taken,
The image data is stored in a storage unit, and then the color temperature is detected by the first color temperature detection unit, and the white balance control unit is configured to detect the color temperature based on the color temperature detection result of the first color temperature detection hand 2. The image processing apparatus according to claim 1, wherein a gain adjustment value is calculated and set in said gain adjustment means, white balance adjustment is performed on the image data stored in said storage means, and thereafter the image data is recorded on a recording medium. 4. The digital camera according to any one of items 1 to 3, 5. An aperture plate provided with the diffusion plate filter or the milky white filter, and an aperture driving unit for moving the aperture to insert and withdraw the diffusion plate filter or the milky white filter into an optical path. The digital camera according to claim 3, further comprising: 6. A shutter provided with the diffusion plate filter or the milky white filter, and shutter driving means for driving the shutter to insert and retract the diffusion plate filter or the milky white filter into an optical path. The digital camera according to claim 3, wherein: 7. A liquid crystal plate which switches between a light scattering state and a transparent state depending on whether or not an electric field is applied in an optical path;
A liquid crystal panel driving unit that drives the liquid crystal panel by applying an electric field, wherein the first color temperature detection unit performs color temperature detection based on incident light incident through the liquid crystal plate in a light scattering state. 3. The digital camera according to claim 1, wherein said second color temperature detecting means detects a color temperature based on incident light incident through a liquid crystal plate in a transparent state. 8. When the amount of incident light or the gain adjustment value exceeds a predetermined value during the monitoring, the selection means selects the first color temperature detection means, and the white balance control means 8. The digital camera according to claim 7, wherein a gain adjustment value is calculated based on a color temperature detection result of the first color temperature detection means, and the gain adjustment value is set in the gain adjustment means to control a white balance.