JPS61214890A - Camera device - Google Patents

Abstract

PURPOSE:To adjust satisfactorily the white balance even under the mixed light by detecting fluorescent lamp information included in illuminating light, calculating illuminating information from fluorescent lamp information and light quantity information of the illuminating light and correcting the illuminating information. CONSTITUTION:The output of an image pick-up element 101 is separated to R, G and B signals by a separating circuit 102. An object light is detected by an R signal detecting device 109 and a B signal detecting device 110, and is supplied through a differential amplifier 114 to a control voltage generating device 116. The output signal of the amplifier 114 is inputted to a fluorescent lamp detecting device 115, and the detected fluorescent lamp information and the light quantity information of a detecting device 108 for measuring the light are inputted to a comparison arithmetic circuit 117. From the illuminating condition judged by the circuit 117, a correcting voltage generating device 118 is controlled. A control voltage converting device 119 is controlled by the detecting device 115, and the control voltage from the generating device 116 is corrected to control variable gain type video amplifiers 103 and 104. Thus, even under the mixed light, the white balance can be satisfactorily adjusted.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to camera devices such as electronic camera devices, and particularly to white balance adjustment thereof.

Conventional technology A conventional camera device will be explained using FIG. 3.

FIG. 3 shows a circuit diagram of a conventional camera device. Third
In the figure, 301 is an image sensor, 302 is an image sensor 30
Separation circuit that separates the output of 1 into R, Y, and B signals, 303
．． 304 is a video amplifier having a voltage-controlled variable gain section; 305 is a differential amplifier for obtaining an RY signal; 30
6 is a differential amplifier for obtaining a BY signal, and 307 is an encoder. 308.309.310 are various fields.

Photodetectors 311, 312°3 that detect green and back light components
13 is an amplifier for the photodetector output of each color component, 314°31
6 is a differential amplifier.

The white balance adjustment of the conventional camera device configured as described above is carried out using the image sensor 301 and the detectors 308, 309, and 310, which detect red, green, and blue light components independent of the image sensor 301. After obtaining optical component signals of each color from the subject (corresponding to the subject) and amplifying them with amplifiers 311, 312, and 313, differential amplifiers 314 and 315 obtain optical component signals of "red-green" and "blue-green." The obtained optical component signal is used as a control signal to change the gains of the variable gain video amplifiers 303 and 304, and the output signals of the separation circuit 302, R and H
differential amplifiers 305 and 30 by controlling the level of the video signal of
White balance adjustment is automatically performed by adjusting the color difference signals (R-Y) and (B-Y) that are the outputs of 6.

Problems to be Solved by the Invention However, according to the above auto white balance circuit, the photodetectors 308, 309, and 310 cannot detect the subject light under sunlight or a tungsten lamp, etc., which can approximate the spectrum of black body radiation. R,G.

If the B component is detected, an appropriate white balance can always be obtained. However, when the light source is a fluorescent lamp, etc., the fluorescent lamp light source has a unique spectrum that is different from the spectrum of black body radiation. When using this method, a deviation occurs in the amount of white balance adjustment, and good white balance adjustment cannot be performed.

Therefore, in order to be compatible with special light sources such as the above-mentioned fluorescent lamps, we have developed a special white nozzle circuit that uses a sensor to detect the spectrum of the three primary colors R, G, and B, and also detects the unique spectrum using another sensor. Kaisho 57-1273
This is shown in Publication No. 76. However, since this circuit requires multiple sensors and there are many types of fluorescent light sources, it also has the drawback of using a large number of sensors and complicating the circuit configuration, resulting in high costs.

In addition, Japanese Patent Laid-Open No. 69-141 developed a white balance circuit that distinguishes between a fluorescent light source and other light sources by detecting flicker with a light receiving element in the light emitted by the fluorescent light source.
This is shown in Japanese Patent No. 888.

However, in actual photography, sunlight or tungsten lamps, which can approximate blackbody radiation, may be mixed with special light sources such as fluorescent lamps, so simple flicker can be detected and the fluorescent light source can be detected. There is a problem in that simply detecting the presence of the camera does not result in a good white balance adjustment suitable for the shooting condition.

SUMMARY OF THE INVENTION In view of the above, an object of the present invention is to provide a camera device equipped with a white balance circuit that can perform white balance adjustment suitable for actual photographing conditions.

Means for Solving the Problems In order to solve the above problems, the present invention provides means for detecting a fluorescent light source included in illumination light, means for obtaining light amount information of illumination light, and outputs of the above two means. This camera device includes means for obtaining illumination information from a signal and means for correcting a control voltage from the illumination information.

According to the above-described configuration, the present invention detects the fluorescent light source included in the illumination light, judges the illumination light using the detection signal and the light amount information of the illumination light, and even under mixed illumination light. Perform good white balance adjustment.

Embodiment FIG. 1 shows a block diagram of a camera device according to a first embodiment of the present invention. In FIG. 1, 101 is an image sensor, 102 is a separation circuit that separates the output of the image sensor into R, Y, and H, 103 and 104 are video amplifiers having a voltage-controlled variable gain section, and 105 and 106 are R-
A differential amplifier 107 is an encoder for obtaining a Y signal and a BY signal. 108 is a photometric photodetector, 109
, 110 are photodetectors that detect R and B signals from a subject with a wide angle of view, respectively, 111 is an amplifier, 112° 113
114 is a logarithmic amplifier for amplifying the signals corresponding to each red and blue regardless of the intensity of light; 114 is a differential amplifier for detecting the signal level difference between blue and red; 116 is included in the output signal of the differential amplifier. A fluorescent lamp detector electrically detects flicker of the fluorescent lamp light source and ripples; 116 is a control signal generation circuit that converts the output signal of the differential amplifier into necessary voltage characteristics;
Reference numeral 117 indicates a comparison operation circuit for determining illumination light based on the output signal of the amplifier 111 which is light amount information and the output signal of the fluorescent lamp detector 116 which indicates fluorescent lamp information. A circuit 119 that generates a correction voltage for correcting the output signal of the control voltage generation circuit 116 is a control voltage converter that adds or subtracts a correction voltage based on the output signal of the fluorescent lamp detector 115.

The operation of the camera device of this embodiment configured as described above will be explained below.

R signal from photoelectric light weight R1 obtained by detecting wide-angle object light with No. 84 detector 109 and B signal detector 110;
The B signals are led to logarithmic amplifiers 112 and 113, respectively, and are converted into logarithmic values 10q IR and 10q IB. The output signal of the logarithmic amplifier is led to a differential amplifier 114,
A signal of R-1oqlB=loq(IH/IB> is output. This output signal 1oq(IH/IB) is a signal indicating color temperature information unrelated to the amount of incident light, so the control voltage generator 116 outputs a white signal. Control voltages vR1 and vB1 with "color temperature-voltage" characteristics necessary for balance adjustment
is converted to The output signal of the differential amplifier 114 is input to a fluorescent lamp detection circuit 115, which detects the fluorescent lamp component contained in the illumination light. Then, using the fluorescent lamp information, which is the fluorescent lamp component in this illumination light, and the light amount information from the photometric detector, the comparison calculation circuit 117 determines the lighting condition based on the ratio of the fluorescent lamp information and the light amount information. The correction voltage generator 118 is controlled to generate a correction voltage value ΔR2ΔB suitable for the illumination state.

The control voltage converter 119 is controlled by the fluorescent lamp detector 116, and when the fluorescent lamp detector determines that the illumination light is a light source other than a fluorescent lamp, it outputs the aforementioned control voltages vR1 and vB1 as they are. However, when it is determined that it is a special light source such as a fluorescent lamp, a correction voltage ΔR2ΔB corresponding to the illumination state is added or subtracted from the control voltages vR1 and ■B1, and the corrected voltages ΔR2ΔB are output.

By controlling the variable gain type video amplifiers 103 and 104 using the output voltages VR and VB, it is possible to obtain a signal with white balance.

In the camera device of this embodiment configured as described above, when the fluorescent light detection circuit determines that the illumination light is a special light source such as a fluorescent lamp, the illumination information obtained from the fluorescent lamp information and the light amount information is used. Since the correction is performed using the correction voltage determined by , it is possible to obtain a control voltage that matches the illumination light, and it is possible to perform good white balance adjustment.

Next, FIG. 2 is a block diagram of a camera device showing a second embodiment of the present invention. The figure shows a portion for obtaining a control voltage, which is different from the first embodiment. 201 is a control signal generation circuit that generates a control voltage with required voltage characteristics based on color temperature information; 202 is a comparison calculation circuit that discriminates illumination light from light amount information and fluorescent lamp information; and 203 is a control signal generation circuit of the control voltage generation circuit 201. 204 is a circuit that generates a first correction voltage for correcting the output signal; 204 is a circuit that generates a second correction voltage for correcting the output signal of the control voltage generation circuit 201 based on the output signal of the comparison calculation circuit 202; 206 is a fluorescent circuit; A circuit 206 adds or subtracts the output signal of the correction voltage generator 2 to the output signal of the correction voltage generator 1 based on the lamp information, and 206 is a control voltage converter that adds or subtracts the output signal of the addition/subtraction circuit 206 based on the fluorescent lamp information.

The operation of the camera device of the second embodiment configured as described above will be described below. The output signals ΔR1 and ΔB1 of the correction voltage generator 1 are signals for correcting the output signals vR1 and vB1 of the control signal generation circuit when the illumination light is a special light source such as a fluorescent lamp. When the illumination light is a mixture of a light source that can be considered as black body radiation and a special light source such as a fluorescent lamp, the output signals ΔR2 and ΔB2 of the correction voltage generator 2 are determined by a comparison calculation circuit based on the ratio of light amount information and fluorescent lamp information. This is a signal for obtaining information and further correcting the first correction voltages ΔR1 and ΔB1 based on this illumination information.

In this way, when the illumination is other than a fluorescent lamp, the control signals ■R1 and vB1 obtained from the color temperature information are output from the control voltage converter, and when the illumination is a special light source such as a fluorescent lamp, the control signals ■R1 and vB1 obtained from the color temperature information are output from the control voltage converter. Control the addition/subtraction circuit to obtain the first correction voltages ΔR1, ΔB
1 is output as a correction signal ΔR9ΔB from the adder/subtractor circuit and outputted as vRl by the control voltage converter.

vBl is corrected and output. In addition, when the lighting is a mixture of a special light source such as a fluorescent lamp and a light source such as the sun, lighting information is obtained from the ratio of light quantity information and fluorescent lamp information using a comparison calculation circuit, and control is performed using this lighting information. Second correction voltage ΔR2,
Using ΔB2, the addition/subtraction circuit calculates the first correction voltages ΔR1, Δ
B1 is further corrected to obtain a correction signal ΔR1 that matches the illumination state.
Using this correction signal from which ΔB is obtained, vRl and vBl are corrected by a control voltage converter and output. In this way, it is possible to obtain control voltages Vn and Vn suitable for all lighting conditions, and to obtain a signal with appropriate white balance. The correction voltage for the special light source is further corrected with a second correction voltage controlled by the lighting information to obtain a correction signal that matches the lighting condition, so that more reliable white balance adjustment can be performed.

Furthermore, in the configuration in which the correction voltage generator in the first embodiment and the correction voltage generator 2 in the second embodiment obtain the necessary correction voltage using illumination information, the correction voltage generator is The configuration has a "lighting information-correction voltage" characteristic in which the correction voltage changes continuously with respect to the information, and the necessary correction voltage is obtained by the output signal of the comparison calculation circuit, or the correction voltage generator performs discrete correction. A conceivable configuration is that the circuit has a function of generating a voltage, and a discrete correction signal is selected based on the output signal of the comparison calculation circuit.

In addition, although the first embodiment shows a case where white balance adjustment is performed using R, Y, and B signals, the invention is not limited to this, and a configuration in which an NTSC signal is obtained by an encoder is shown, but other cameras using color difference signals may be used. As described in detail, according to the present invention, it is possible to obtain a correction signal that matches the lighting condition, so even when fluorescent lamps and sunlight are mixed, it is possible to obtain a corrected signal that is suitable for the lighting conditions. This allows for accurate white balance adjustment, which has great practical effects.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a camera device according to a first embodiment of the present invention, FIG. 2 is a block diagram of a camera device according to a second embodiment, and FIG. 3 is a block diagram of a conventional camera device. 1o1...Image sensor, 102...Separation circuit, 103, 104...Variable gain video amplifier, 105°106...Differential amplifier, 107
... Encoder, 108 ... Photometry detector, 109 ... R signal photodetector, 110 ...
... B signal photodetector, 111 ... amplifier,
112, 113... Logarithmic amplifier, 114...
... Differential amplifier, 115 ... Fluorescent lamp detector,
116... Control signal generation circuit, 11 completion...
... Comparison calculation circuit, 118 ... Correction voltage generator, 119 ... Control voltage converter, 203 ...
. . . Correction voltage generator 1.204 . . . - Correction voltage generator 2.206 . . . Addition/subtraction circuit.

Claims (5)

[Claims] (1) A color image sensor, a plurality of photodetectors that are independent of the color image sensor and have mutually different spectral sensitivity characteristics, and calculate the output signals of these photodetectors to obtain color temperature information of illumination light. control voltage generating means for generating a control voltage for white balance adjustment of the output of the color image sensor based on the color temperature information from the first calculating means; and light amount information of illumination light. a means of obtaining
a fluorescent lamp information detecting means for detecting a fluorescent light source included in the illumination light; a second calculating means for calculating the fluorescent lamp information and the above-mentioned light quantity information to obtain illumination information; A camera device comprising a correction means for determining and correcting the control voltage. (2) The camera device according to claim 1, wherein the correction means for correcting the control voltage is configured to control a DC component to be added to or subtracted from the output signal of the control voltage generation means. (3) The camera device according to claim 1, wherein the second calculation means for obtaining illumination information is configured to obtain a ratio between fluorescent light information and light amount information. (4) The camera device according to claim 1, wherein the means for determining the correction voltage based on the illumination information obtains a necessary correction voltage value from among the correction voltages that continuously change with respect to the illumination information. . (5) The camera device according to claim 1, wherein the means for determining the correction voltage based on the illumination information is configured to select from among discrete correction voltages using the illumination information.