JP2535875B2 - Color camera device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a color camera device that forms a color video signal from three primary color signals obtained by shooting a subject image in a color imaging unit and outputs the color video signal.

[Outline of Invention]

The present invention relates to a color camera device that forms and outputs a color video signal from three primary color signals obtained by shooting a subject image in the color image pickup section, and a white balance shift of the three primary color signals obtained by the color image pickup section is generated. A warning is displayed when the number exceeds a predetermined value.

[Conventional technology]

Generally, in a color camera device, image pickup light from a subject is separated into three primary color light components R, G, and B by a color separation system, and color image pickup is performed by a pickup tube or a solid-state image sensor. To form
When the color temperature changes due to the lighting conditions during image capturing, the white balance is lost and the color reproducibility is impaired.Therefore, in order to obtain a color video signal with good color reproducibility, the white balance should be adjusted according to the color temperature during image capturing. Need to be adjusted accurately.

In white balance adjustment, a white subject is shot and the ratio of the red component signal level Er, the green component signal level Eg, and the blue component signal level Eb of the image output is Er: Eg: Eb.
This is performed by setting the level adjustment circuit provided in each color signal line so that = 1: 1: 1. Conventionally,
A color balance device such as disclosed in Japanese Patent Publication No. 53-2290 and Japanese Patent Publication No. 56-24884, which gates the imaging output of the white portion of the subject image and detects the white balance error to perform automatic white balance adjustment. A television camera and the like disclosed in the publication are provided.

[Problems to be solved by the invention]

By the way, in general, in a color camera device, since a color image is taken while monitoring a subject image being photographed with a black and white viewfinder, it is often not noticed even if the white balance is lost during photographing. . Traditionally, color camera devices have been designed so that white balance adjustment can be performed automatically or manually according to the lighting conditions during shooting, etc., but with an automatic white balance adjustment function. Even a color camera device does not constantly shoot a white subject, so that the white balance may be significantly lost.

Therefore, in view of the above-described problems, the present invention displays a warning when the white balance is collapsed more than a predetermined amount during color photography to alert the photographer, and the deterioration of the color reproducibility due to the white balance error. The present invention provides a color camera device having a novel structure capable of preventing the above.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention provides a color camera device that forms and outputs a color video signal from three primary color signals obtained by shooting a subject image in a color image pickup unit, and outputs from the color image pickup unit. A gate signal forming means for forming a white balance gate signal from a signal obtained by combining the three primary color signals, a gate means for respectively gated the three primary color signals by the gate signal, and a predetermined three primary color signals gated by the gate means. By comparing the color signal levels averaged over a period to obtain the signal level ratio of the other color signal to the specific color signal and comparing it with the preset signal level ratio, the deviation of the white balance becomes more than a predetermined value. A warning display signal forming means for detecting an increase and forming a warning display signal is provided, and is obtained by the color imaging unit. Deviation of the white balance of the primary color signals is characterized in that to perform the warning display when increased above a predetermined.

[Action]

In the color camera device according to the present invention, a white balance gate signal is formed from a signal obtained by synthesizing the three primary color signals output from the color imaging unit, and the white level gate signal is gated by the gate signal. A white balance shift of the three primary color signals obtained by the color image pickup unit is detected and a warning is displayed.

〔Example〕

An embodiment of a color camera device according to the present invention will be described below in detail with reference to the drawings.

The embodiment shown in FIGS. 1 to 3 has three CCDs (Cha
The present invention is applied to a so-called three-plate color video camera in which the color image pickup unit 1 is configured by image sensors 1R, 1G, and 1B.

In this embodiment, the three primary color signals (Er, Eg, Eb) obtained by picking up a subject image with the CCD image sensors 1R, 1G, 1B of the color image pickup unit 1 are as shown in FIG. It is supplied to the white balance adjusting circuit 3 via the preamplifiers 2R, 2G and 2B, and the white balance adjusting circuit 3 performs the white balance adjustment, and then the encoders via the process processing circuits 4R, 4G and 4B, respectively. 5
And the white balance processing circuit 6.

The encoder 5 includes the process processing circuits 4R, 4G,
A color image signal (Sout) conforming to, for example, the NTS system is formed from the three primary color signals (Er, Eg, Eb) that have undergone process processing such as gamma correction at 4B, and are output from the first signal output terminal 7. . Further, the encoder 5 outputs a video signal (Seb) for displaying an image of a subject imaged by the color image pickup unit 1 on a screen of an electronic viewfinder (not shown), which has been subjected to the process-processed three primary color signals (Er, Eg, E
It is formed from b) and is supplied to the signal synthesizer 8.

The signal synthesizer 8 synthesizes the display output signal (A) supplied from the white balance processing circuit 6 described below with the video signal (Seb) and outputs it from the second signal output terminal 9 to an electronic viewfinder (not shown). We are supplying.

Further, the white balance processing circuit 6 has three specific color signals (Er, Eg, Eb) output from the process processing circuits 4R, 4G, 4B as shown in FIG.
Is supplied to the signal adder / combiner 11 and is also supplied to the sampling gate circuit 13 via the multiplex 12.

The signal adder / synthesizer 11 is configured to output the three primary color signals (Er, Eg, E
b) is added and combined to form a combined signal (S) having a signal level indicating the brightness level of the subject image photographed by the image pickup unit 1, and the combined signal (S) is used for the peak detection circuit 14 Is being supplied to. And the peak detection circuit
A sampling gate circuit 13 detects a peak level portion of the composite signal (S), that is, a white portion of a subject image, and uses the detection output as a white balance gate signal.
Supply to.

Further, the multiplexer 12 outputs the three primary color signals (Er, Eg, Eb) every one frame period, that is, every two field periods.
Are controlled by the microcomputer 16 so as to sequentially select. Furthermore, the above sampling gate circuit
Reference numeral 13 denotes an analog signal obtained by sampling the three primary color signals (Er, Eg, Eb) sequentially supplied for each frame period via the multiplexer 12 with the white balance gate signal supplied from the peak detection circuit 14. Digital (A / D)
It is supplied to the conversion circuit 15. The A / D conversion circuit 15 digitizes the three primary colors (Er, Eg, Eb) of the white portion of the subject image sampled by the sampling gate circuit 13, and color data (Dr, Dg, Db) is supplied to the microcomputer 16.

In this embodiment, the microcomputer 16
Is a color data (Dr) indicating each signal level of the three primary color signals (Er, Eg, Eb) obtained by the image pickup unit 1 by photographing a reference white object under the color temperature of the image pickup light source. , Dg, Db), the ratio of each signal level of the other color signal (Er, Eb) to the green signal (Eg) is calculated, and the signal levels of the above three primary color signals (Er, Eg, Eb) are matched. The red level control signal (Δr) and the blue level control signal (Δb) are transferred from the white balance control circuit 17 to the gain control circuit 3R of the red signal (Er) and the blue signal (Eb) of the white balance adjusting circuit 3 described above. The control data for supplying the gain control circuit 3B to secure the white balance is stored in advance in the memory.
It is stored in 18, and the white balance adjustment operation is performed by the above control data at the time of the actual imaging operation.

Further, the microcomputer 16 performs a white balance adjustment operation by the control data during the actual shooting operation, and uses each color data (Dr, Dg, Db) supplied from the A / D converter 15 to The display control operation shown in the flowchart of FIG. 3 is performed.

That is, in the warning display operation by the microcomputer 16, first, the A / D conversion indicating the signal levels of the three primary color signals (Er, Eg, Eb) of the white part of the subject image actually photographed by the imaging unit 1 is performed. Color data (Dr, D
g, Db) are sequentially written to the data memory 17. Then, for each of the color data (Dr, Dg, Db), average value data (Ar, Ag, Ab) of the values for several times are calculated. Next, the display mode is judged, and in the warning display mode, Ar / Ag, Ab / Ag is calculated from the average value data (Ar, Ag, Ab), and the white balance deviation judgment reference value (Kr, Kb), it is judged whether it is within the reference range of 1 / Kr <Ar <Ag <Kr 1 / Kb <Ab <Ag <Kb. If it is outside the reference range, [COLOR TEMP.HIGH] , [COLOR TEMP.LOW] and other display outputs are output from the character generator 19 to display a warning, and if they are within the reference range, the display is erased.
When the result of the display mode determination is the color temperature display mode, the deviation amount from the white balance state indicated by the value of Ar / Ab obtained from the average value data (Ar, Ag, Ab) and the imaging optical The actual color temperature value is calculated from the types of filters arranged in the system and the gain control amounts of the gain control circuits 3R and 3B of the white balance adjustment circuit 3 described above, and the display output of this value is displayed by the character generator 19 To display the color temperature.

〔The invention's effect〕

As is clear from the above description of the embodiments, in the color camera device according to the present invention, a white balance gate signal is formed from a signal obtained by combining the three primary color signals output from the color image pickup unit, and the gate signal is used to gate From the signal level ratio of the above three primary color signals, a warning display is performed by detecting the deviation of the white balance of the three primary color signals obtained by the color image pickup unit, so when the white balance is destroyed more than a predetermined amount during color shooting, The above warning display alerts the photographer to prevent deterioration of color reproducibility due to a white balance error, and color photography with good image quality can be performed.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a color camera device according to the present invention, FIG. 2 is a block diagram showing a specific configuration of a white balance processing circuit in the above embodiment, and FIG. 7 is a flowchart for explaining a warning display control operation by a microcomputer provided in the white balance processing circuit. 1 ... Imaging unit 1R, 1G, 1B ... CCD image sensor 3 ... White balance adjustment circuit 3R, 3B ... Gain control circuit 5 ... Encoder 6 ... White balance processing circuit 8 ... Signal synthesizer 11 ... Signal adder / synthesizer 12 …… Multiplexer 13 …… Sampling gate circuit 14 …… Peak detection circuit 15 …… A / D converter 16 …… Microcomputer 17 …… White balance control circuit 19 …… Character generator

Claims (1)

(57) [Claims] 1. A color camera device for forming and outputting a color video signal from three primary color signals obtained by photographing a subject image in a color image pickup section, from a signal obtained by combining the three primary color signals output from the color image pickup section. Gate signal forming means for forming a white balance gate signal, gate means for respectively gated the three primary color signals by the gate signal, and three primary color signals gated by the gate means,
By comparing the color signal levels averaged over a predetermined period to obtain the signal level ratio of the other color signal to the specific color signal and comparing it with a preset signal level ratio, the deviation of the white balance is more than a predetermined value. And a warning display signal forming means for forming a warning display signal by detecting that the white balance deviation of the three primary color signals obtained by the color image pickup unit increases more than a predetermined value. A color camera device characterized by the above.