JPH0470179A - Electronic still camera device - Google Patents

Abstract

PURPOSE:To obtain the picture of a good color reproducibility with well balanced white even when photographing under a light source mixed with the surrounding light of an object and irradiating light by providing a color temperature detecting means, a illuminance detecting means, a light emitting means, an automatic white balance means and a gain controlling signal arithmetic means. CONSTITUTION:A YL signal obtained by a photographing signal processing circuit 3 is inputted in the integration smoothing circuit 6 of the illuminance detecting means, and inputted in a gain controlling signal arithmetic circuit 9. The gain controlling signal arithmetic circuit 9 is provided the color temperature detecting means for inputting light from a light sensor 8 and detecting color temperature information as well. A gain controlling signal, which gain- controls a color signal and a luminance signal to be calculated by a signal obtained by the light sensor 8 detecting the color temperature of the surrounding of the object, is corrected corresponding to the emitted light quantity of a strobo. Thus, even when photographing under the light source mixed with the surrounding right of the object and the strobo light, the picture of the good color reproducibility with well balanced white can be easily obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an electronic still camera device that records a subject as a still image on a floppy disk.

Prior Art The conventional technology will be explained below with reference to FIG. The optical image of the subject is input to the photographing element 2 through the lens 1, where the optical image is converted into an electrical signal, which passes through the photographing signal processing circuit 3 and is converted into a luminance signal (hereinafter abbreviated as 1'Y signal) and a band-limited luminance signal. The signal is separated into a signal (hereinafter abbreviated as Y1 signal) and a color signal. The color signal is roughly separated into an R signal and a B signal through a color signal separation circuit 5.

Further, the diffuser plate 7 inputs a wide range of light around the electronic still camera to the optical sensor 8, and the ambient light of the subject manually applied to the optical sensor 8 is converted into an electrical signal, and the color temperature calculation circuit 23 receives the manually applied light. be done. The color temperature calculation circuit 23 has color filters of 83 colors, R, G, arranged between the diffuser plate 7 and the optical sensor 8, and the color temperature calculation circuit 23 has color filters of 83 colors, R, G, arranged between the diffuser plate 7 and the optical sensor 8.
(The color temperature around the subject is detected using the B signal and the G signal.) Calculates and creates a signal (abbreviated as "signal").

Therefore, when not flash photography, the switch 24 is set to the A side and the switch 25 is set to the C side, and the gain control signal based on the input information of the optical sensor 8 is sent to the R gain control circuit 13 and the B side.
The signal is input to the gain control circuit 14 and becomes a gain control signal.

Furthermore, during strobe photography, the strobe light emission control circuit 12 outputs a strobe light emission command signal to the strobe II.
The strobe lights up. The strobe sensor 10 detects the reflected light from the subject of the strobe, and when the predetermined amount of light is reached, it outputs a detection signal to the strobe light emission control circuit 12 to stop the strobe light emission l-. When strobe light is emitted, the strobe sensor is output from the strobe light emission control circuit 12 to switch 24 and switch 25, and switch 2
4 is set to B tPll, the switch 25 is set to the D side, and the signal previously recorded in the nonvolatile memory 26 is
It is output as an r signal and a b signal.

The R signal and B signal output from the color signal separation circuit 5 are input as controlled signals to the R gain control circuit 1; , a color difference signal R-YK with a good white balance by the differential amplifier circuit 15, and a color difference signal B-Yl- with a good white balance by the differential amplifier circuit 16, Y signal, R-YL signal. , B
-YL signal is manually inputted to the recording signal processing circuit 17,
Processing such as FM modulation is performed, and the recording circuit 18 outputs the recording medium 19.
recorded in Reference numeral 20 denotes a drive circuit for driving the recording circuit 18. Problems to be Solved by the Invention However, the electronic still camera device configured as described above does not produce white light when shooting without strobe light or when only strobe light is illuminated on the subject. It is possible to take well-balanced shots with good color reproducibility, but white balance cannot be achieved when shooting with a mixture of light around the subject and strobe light, especially when shooting with halogens, which have a low color temperature. When photographing with a mixture of light and strobe light with a high color temperature, there has been a problem in that color reproducibility is significantly degraded.

In view of the problems with conventional electronic still camera devices, the present invention has been developed to provide an electronic still camera device that can obtain image quality with good white balance and good color reproducibility even when photographing under a light source in which ambient light and irradiation light of the subject are mixed. The purpose is to provide a still camera device.

Means for Solving the Problems The present invention provides a color temperature detection means for detecting the color temperature of the surroundings of a subject, an illumination detection means for detecting the brightness of the subject to be photographed, a light emitting means for emitting light, and a color signal and a color signal. and/or automatic white balance means that performs gain control on the luminance signal to automatically perform white balance so that the color difference signal becomes zero when photographing an achromatic subject; The automatic white when the light emitting means does not emit light obtained by the color temperature detecting means according to the brightness detection signal in the instant detection means and the brightness detection signal when the light emitting means emits light. The gain in the automatic white balance means is adjusted by changing the combination ratio of the first gain control signal which is most suitable in the balance means and the second gain control signal bi which is most suitable in the automatic white balance means when light is emitted by the light emitting means. The present invention is an electronic still camera device characterized by comprising a gain control signal calculation means used as a control signal.

Effect of the present invention With the above-described configuration, the color temperature around the subject is calculated using a signal obtained by an optical sensor that detects the color temperature around the subject.
The gain control signal that controls the gain of the color signal and brightness signal is corrected according to the amount of light emitted by the strobe, so the light is a mixture of the ambient light of the subject and the robot light! Even when shooting at 'l', it is possible to easily obtain image quality with good white balance and good color reproducibility.

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows a 70 block diagram of an electronic still camera device according to a first embodiment of the present invention.

In the figure, 1 to 3, 5, 7, 8, and 10 to 20 have basically the same functions as the conventional example, so their explanation will be omitted.

4 is an image memory that stores both image signals, and 6 is Y of the image signal.
A circuit for integrating and smoothing the L times signal, and 9 a gain control signal calculation circuit for calculating a gain control signal as described later.

Next, the operation of this embodiment will be explained.

As described in the conventional apparatus, the color signal obtained by the photographing signal processing circuit 3 is input to the image memory 4 having a field or frame capacity, and after being stored, is output to the color signal separation circuit 5. .

Since strobe light emission is instantaneous, it is necessary to store the signal at the time of strobe light emission in the image memory 4.

Moreover, the YL signal obtained by the photographing signal processing circuit 3 is as follows.
The signal is input to an integral smoothing circuit 6 as an example of illuminance detection means, becomes a DC value, and is input to a gain control signal calculation circuit 9 as an example of gain control signal calculation means. The gain control signal calculation circuit 9 includes a nonvolatile memory 26 in FIG.
and a memory for storing the DC value output from the integral smoothing circuit 6. It also includes color temperature detection means for inputting light from the optical sensor 8 and detecting color temperature information.

The r signal based on the color temperature information around the subject received by the optical sensor 8 is assumed to be rl, and the b signal is assumed to be b+. Further, during strobe light emission, the r signal and b signal stored in the nonvolatile memory built in the gain control signal calculation circuit 9 are respectively referred to as r2 and the b signal as b2. Furthermore, if the output of the integral smoothing circuit 6 when the strobe does not emit light is S1, and the output of the integral smoothing circuit 6 when the strobe is emitting light is S2, then SIX r(+ S 2X r 2 Sl+52 Correction can be applied according to the amount of increase in brightness of the subject.

The subsequent processing is as explained in connection with the circuit of FIG.

Next, a second embodiment of the present invention will be described based on the block diagrams in Figures 1 and 2. In Figures 1 to 21), the functions are basically the same as those of the conventional example, so the explanation thereof will be omitted.

The AE sensor 21, which is an example of illuminance detection means, is a means for detecting the brightness of a subject to be photographed.

The detected signal is input to the gain control signal calculation circuit 22. Like the embodiment shown in FIG. 1, this gain control signal calculation circuit 22 includes a nonvolatile memory 26 and also serves as color temperature detection means. The r signal based on the color temperature information around the subject received by the optical sensor 8 is set to 3, and the b signal is set to l.
)3. Further, the r signal and b signal stored in the nonvolatile memory built in the gain control signal calculation circuit 22 during strobe light emission are respectively referred to as rl and bl.

The signal output to the AE sensor 21 when the strobe does not emit light is 83, and the signal when the strobe does emit light is S4.
Then, S 3 It is possible to apply corrections accordingly.

Note that the color temperature detection means may be realized using other means such as an imaging device without using an optical sensor.

EFFECTS OF THE INVENTION As described above, according to the present invention, with a simple configuration, it is possible to automatically balance the amount of ambient light and strobe light when photographing under a light source in which ambient light and strobe light are mixed. The effect is extremely large, as it is easy to detect images with good white balance and good color reproduction.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a first embodiment of an electronic still camera device according to the present invention, FIG. 2 is a block diagram of a second embodiment, and FIG. 3 is a block diagram of a conventional electronic still camera device. 4... Image memory, 5... Color signal separation circuit, 6...
- Integral smoothing @vII (illuminance detection means), 8... Optical sensor - 9, 22, 23... Gain control signal calculation circuit (color temperature detection means, gain control signal calculation means), 10... - Strobe sensor ll...Stroboscope, 12◆...Strobe generation control circuit, 13...R gain control circuit, 14.
Australia B gain IFJ return! ! iI. Agent Patent Attorney Matsu 1) Masamichi

Claims (1)

[Scope of Claims] Color temperature detection means for detecting the color temperature of the surroundings of a subject; illuminance detection means for detecting the brightness of a subject to be photographed; light emitting means for emitting light; and a color signal and/or a luminance signal. automatic white balance means that automatically takes white balance so that a color difference signal becomes zero when photographing an achromatic subject by controlling the gain; and brightness in the illuminance detection means when the light emitting means does not emit light. and the detection signal of the brightness when the light emitting means emits light, the first optimum brightness in the automatic white balance means when the light emitting means does not emit light obtained by the color temperature detecting means. and the second optimum gain control signal in the automatic white balance means when light is emitted by the light emitting means.
an electronic still camera device comprising: gain control signal calculating means for changing the synthesis ratio of the gain control signals of and using the gain control signal as a gain control signal for the automatic white balance means.