JPS63314424A - Color camera - Google Patents

Abstract

PURPOSE:To enable proper white balance adjustment even when accuracy is worsened in direct color measurement of an irradiation light of an object, by selecting first or second measuring means alternatively. CONSTITUTION:A color measuring sensor 1 measures light source color from light in the perimeter of a camera. Then, a colorimetric measuring sensor computation section 2 computes and outputs a gain control voltage at an R (red) channel (Ch) and a B (blue) channel (Ch) based on an output of the colorimetric sensor 1. A low level luminous intensity detecting circuit 3 detects a limited quantity of light in the perimeter of the camera from the output of the colorimetric sensor 1. Moreover, a video signal computing section 5 computes and outputs a gain control voltage at the RCh and BCh based on an output of a image sensor 4. Then, an amplifier 6 controls a gain at the RCh out of an output of the image sensor 4. An amplifier 7 controls the gain at the BCh to be outputted to a signal processing circuit 8. This enable automation of a proper white balance adjustment.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a color imaging device, and particularly to an improvement in white balance adjustment.

(Prior Art) Conventionally, as an example of white balance adjustment in a color imaging device, a coloring means is provided outside the lens, and the color temperature of the video signal is corrected based on the colorimetric data generated by the coloring means. There is.

(Problems to be Solved by the Invention) However, when the surrounding area where the color imaging device is placed becomes dark, for example when photographing a stage, the accuracy of the color embellishing means deteriorates. Furthermore, in such cases, the distance to the subject is often long, and there is also a problem with the reliability of the embellished color data, resulting in the problem that appropriate white balance adjustment cannot be performed.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to provide a color imaging device that can perform appropriate white balance adjustment even when the accuracy of direct color measurement of illuminating light from a subject deteriorates.

[Means for solving problems]

In order to achieve such an object, the present invention detects the amount of embellishing light outside the lens, and thereby selectively switches the embellishing output of the light source for the outside and the inside of the lens.

That is, the present invention includes first and second coloring means for colorimetrically measuring a light source that illuminates a subject, a detection means for detecting the amount of light from the light source that is incident on the first coloring means, and a detection means,
It is characterized by comprising means for selectively selecting either one of the first and second embellishing means.

[Effect]

According to the present invention, when the amount of incident light from the light source illuminating the subject does not reach a predetermined value with the colorimetric sensor, it is possible to detect this, and accordingly, the white balance adjustment can be switched and controlled. can.

〔Example〕

Hereinafter, the present invention will be described in detail and concretely by way of examples with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes a colorimetric sensor, which measures the light source color from the light around the imaging device. Reference numeral 2 denotes a colorimetric sensor calculation section, which calculates and outputs gain control voltages for the R (red) channel and the B (blue) channel based on the output of the color sensor 1. 3 is a low illuminance detection circuit, and colorimetric sensor 1
It is detected from the output that the amount of light around the imaging device is low. Reference numeral 4 denotes an image sensor, and 5 a video signal calculation section, which calculates and outputs gain control voltages for the R channel and B channel based on the output of the image sensor 4. 6 and 7 are amplifiers, and the amplifier 6 controls the gain of the R channel of the output of the image sensor 4. Amplifier 7 is also B
Control channel gain. 8 is a signal processing circuit.

FIG. 2 is a block diagram showing an example of the configuration of the low-illuminance detection circuit 3 shown in FIG.

In FIG. 2, 9 is a comparator, 10 is a threshold voltage generator, and 11 is an inverter.

The G (green) output from the colorimetric sensor 1 is manually input to the low illuminance detection circuit 3 .

Next, the operation of each component will be explained with reference to FIGS. 1 and 2.

Colorimetric sensor 1 to 3 primary colors R (red), G (green), B (blue)
A voltage proportional to each amount of light is output. Out of these, the output of G is manually inputted to the low-light detection circuit 3. A comparator 9 shown in FIG. 2 compares the threshold voltage from the threshold voltage generator 10 set in advance with the manual power from G of the colorimetric sensor 1, and if the output voltage of the colorimetric sensor 1 is higher, " Outputs “low”. The comparator 9 output is the colorimetric sensor calculation unit 2 shown in FIG.
The output enable (OE) of the output signal is input to the inverter 11 shown in the second diagram. The output of the inverter 11 is the first
The output enable of the video signal calculation section 4 shown in the figure (
OE). In this case, since the output enable of the video signal calculation section 4 is "high", the output of the video signal calculation section 4 becomes high impedance. Colorimetric sensor calculation unit 2
Since the output enable is "low", the gain control voltages for the R channel and B channel are calculated and output based on the output of the colorimetric sensor 1.

On the other hand, the image is converted into R, G, and B electrical signals by the image sensor 4, and the R channel and B channel are amplified by amplifiers 6 and 7, respectively, while being controlled by voltages set by the colorimetric sensor calculation unit 2. Signal processing circuit 8
Output to.

Further, when the amount of light around the imaging device is small and the output voltage of G from the colorimetric sensor 1 shown in FIG. 1 is lower than the threshold voltage from the threshold voltage generator 10 shown in FIG. 2, the comparator 9 outputs "high". do. As a result, the output of the inverter 11 becomes "low", and in the colorimetric sensor calculation section 2 shown in FIG. 1, the output enable becomes "high" and the output becomes high impedance.

Since the output of the inverter 11 shown in FIG. 2 becomes "low", the output enable becomes "low" in the video signal calculation unit 5 shown in FIG. Based on this, gain control voltages for the R channel and B channel are calculated and output.

The image is converted into R, G, and B electrical signals by the image sensor 4 and output. The R channel and the B channel are amplified by amplifiers 6 and 7, respectively, under the control of voltages set by the video signal calculation unit 5, and output to the signal processing circuit 8.

In this embodiment, an example using the low illuminance detection circuit 3 has been described, but similar effects can be obtained by using a microcomputer or other means capable of determining low illuminance.

Further, as the color adding means inside the lens of the imaging device, an example has been described in which white balance adjustment is performed based on the output of the image sensor 4, but as another example, a second colorimetric sensor is configured inside the lens, This may be used as a coloring means inside the lens to perform white balance adjustment based on its detection output.

[Effects of the Invention] As is clear from the above, according to the present invention, even in cases where the surroundings where the color imaging device is placed are dark or where the colorimetric sensor is accidentally blocked by the light, This provides the effect of automatically performing appropriate white balance adjustment.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, and FIG. 2 is a block diagram showing the configuration of an example of low-light detection. DESCRIPTION OF SYMBOLS 1... Colorimetric sensor, 2... Colorimetric sensor calculation section, 3... Low illuminance detection circuit, 4... Image sensor, 5... Video signal calculation section, 6.7... Amplifier , 8... Signal processing circuit, 9... Comparator, 10... Threshold voltage generation section, 11... Inverter. Thick L main button out one row 0 structure ♂? Block diagram shown in Figure 2

Claims (1)

[Scope of Claims] First and second colorimetric means for colorimetrically measuring a light source illuminating a subject; a detecting means for detecting the amount of light from the light source that is incident on the first colorimetric means; and the detection means. A color imaging device comprising means for selectively selecting one of the first and second colorimetric means.