White balance adjusting device for a camera

Abstract

A white balance adjusting device for use in a camera which photographs a field and forms a video signal representing the field. In the white balance adjusting device, while a sequential photographing is under way, updating of the color temperature data to be used for adjusting a white balance is prohibited. Therefore, the hues of main objects in the respective frames of still images photographed by the sequential photographic operation remain unchanged, thereby maintaining the homogeneity of the main objects. Also, in the white balance adjusting device, control a device is used to provide a short response time for a quick response property in a still mode and to provide a longer response time in a movie mode when compared with the still mode. As a result, the white balance can be adjusted according to the photographic modes of the camera.

Description

[0001]This application is a continuation of application Ser. No. 236,992, filed on Aug. 26, 1988.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention relates to a white balance adjusting device for use in a camera in which the image of a field to be photographed is picked up and then a video signal representing the field is created.[0004]2. Description of the Related Art[0005]Recently, there has been developed an attractive electronic still camera system wherein an image pickup device, such as a solid image pickup element, an image pickup tube or the like, is combined with a recording device employing, as a recording medium, an inexpensive magnetic disc having a comparatively higher memory capacity for photographing an object electronically recording the object into the rotating magnetic disc and reproducing an image by a television system or a printer separately provided.[0006]In the above-mentioned electronic still cameras, there is included an ele...

AI Technical Summary

Benefits of technology

[0016]The present invention aims at eliminating the drawbacks found in the above-mentioned conventional devices.

[0017]Accordingly, it is a first object of the invention to provide a camera white balance adjusting device which is capable of maintaining the homogeneity of a main object regardless of the variations of the color temperature of a field when photographing a still image by means of a sequential photographic mode.

[0018]It is a second object of the invention to provide a camera white balance adjusting device which is capable of changing properly the response property of a camera from the detection of the color temperature of a field up to the execution of a white balance adjustment.

[0024]Further, in attaining the second object, according to another aspect of the invention, there is provided a white balance adjusting device for use in a camera in which a field is photographed and a video signal representing the field is formed. The device includes a photographic mode setting device for setting either a still mode for photographing the field as a still image or a movie mode for photographing the field as a moving image, a color temperature detecting device for detecting the color temperature of the field and outputting a color temperature signal representing the color temperature, and a control device for adjusting the white balance of the video signal in accordance with the color temperature data that is obtained from the color temperature signal. The control device takes the set output of the photographic mode setting device and, when the photographic mode is set in the still mode, adjusts the white balance of the video signal at a shorter cycle when compared with the movie mode.

[0025]In the white balance adjusting device for use in a camera according to the invention, the still mode or the movie mode is set by means of the photographic mode setting device. When the photographic mode is set in the still mode for photographing the field as a still image, to provide a quick response, a response time required from the detection of the color temperature of the field up to the execution of the white balance adjustment is controlled to a short amount of time by the control device. In the movie mode, to be able to provide a response property similar to a conventional movie camera, the abovementioned response time is controlled by the control device such that the time is longer than the time in the still mode.

Problems solved by technology

This slow response results because the color temperatures in the natural world vary in a wide range of time but the variations thereof are normally slow.

In the single photographic mode, as discussed above, the white balance adjustment must be made in compliance with the color temperature of the field in the instant of the shutter release, but this cannot apply to the sequential photographic mode.

As a result of this, the image of the object is tinged with the color of the background, which damages the homogeneity (which means that the object is photographed substantially in the same color hue) of the same main object in a plurality of still images picked up by means of the sequential photographic mode.

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