White balance control system for color television camera with automatic switchover control

• US 4,574,303 A
• Filed: 06/21/1983
• Issued: 03/04/1986
• Est. Priority Date: 06/24/1982
• Status: Expired due to Fees

• Current Assignee: Nikon Corporation
• Original Assignee: Nippon Kotsu Kabushiki Kaisha (Nikon Corporation)
• Inventors: Hashimoto, Takaaki, Motoori, Ryuzo, Minagawa, Kazushi
• Primary Examiner(s): Shepperd, John W.
• Application Number:
  US06/506,459
• Time in Patent Office: 987 Days
• Field of Search: 358/29
• US Class Current: 348/227.1
• CPC Class Codes: H04N 23/88 for colour balance, e.g. white-balance circuits or colour temperature control

Abstract

In a color television camera of the type in which the white balance is subjected to automatic follow-up adjustment during the shooting in accordance with the color temperature of an object illuminating light detected by light sensors provided independent of the imaging means, the adjusted condition of the white balance is maintained constant as desired. The TV camera includes change-over switch for switching the white balance control mode between the automatic follow-up mode and the memory mode, memory means for locking the white balance which has been adjusted automatically in the then current condition in response to the change-over to the memory mode, and a controller whereby when the shooting preparatory operation is started with the memory mode being selected the white balance control mode is always changed over to the automatic follow-up mode first thereby effecting the white balance adjustment. Particularly, this change-over to the automatic mode occurs when the power source is coupled to the camera.

Claims

1. A color television camera comprising:

(a) generation means for generating color signals of an object to be shot;

(b) detecting means for detecting a color temperature of a light illuminating said object and generating at least one detection signal in accordance with said detected color temperature;

(c) control means for controlling said generating means so as to adjust the colors of a picture in accordance with said detection signal;

(d) memory means having automatic and memory control modes, said memory means transmitting said detection signal to said control means in said automatic control mode, and said memory means storing said detection signal and outputting said stored detection signal to said control means in said memory control mode;

(e) selection means adapted to select one of said automatic and memory control modes of said memory means;

(f) power source means for energizing said camera; and

(g) change means responsive to the energizing of said camera by said power source means to change over said memory means to said automatic control mode irrespective of said memory control mode selected by said selection means.

2. A color television camera according to claim 1, wherein said change means includes timer means responsive to said energizing of said camera by said power source means so as to hold said memory means in said automatic control mode for a predetermined time and then change over to said memory control mode.

3. A color television camera according to claim 1, further comprising:

(a) shooting starting means adapted to be operated to cause said color television camera to start a shooting when said color television camera has been energized; and

(b) means responsive to said starting of shooting to hold said memory means in the preliminarily selected mode in accordance with said change means.

4. A color television camera according to claim 1,

wherein said generation means generates said color signals in accordance with the color temperature of said object and

wherein said color television camera further includes:

(a) filter means having a plurality of color temperature conversion filters for converting the color temperature of said object including means for selecting one of said plurality of color temperature conversion filters; and

(b) means including a plurality of potential levels for adding one of said plurality of potential levels to said detection signal in response to the color temperature conversion fitler selected by said filter means.

5. A color television camera comprising:

(a) generating means for generating color signals of an object to be shot;

(b) detecting means for detecting a color temperature of a light illuminating said object and generating at least one detection signal in accordance with said detected color temperature;

(c) control means for controlling said generation means so as to adjust the colors of a picture in accordance with said detection signal;

(d) memory means having automatic and memory control modes, said memory means transmitting said detection signal to said control means in said automatic control mode, said memory means storing said detection signal and outputting said stored detection signal to said control means in said memory control mode;

(e) selection means adapted to select one of said automatic and memory control modes of said memory means;

(f) power source means for energizing said camera and deenergizing said camera; and

(g) changing means responsive to said deenergizing of said camera by said power source means to change over said selection means to the first control mode when the second control mode has been selected.

6. A color television camera according to claim 5 wherein said selection means is displaceable between a first position for said memory control mode and a second position for said automatic control mode;

and wherein said changing means includes;

(a) means for biasing said selection means from said first position toward said second position;

(b) means for holding said selection means in said first position; and

(c) means responsive to the deenergizing of said camera by said power source means to release the holding of said selection means by said holding means.

7. A color television camera according to claim 5,

wherein said generation means generates said color signals in accordance with the color temperature of said object;

and

wherein said color television camera further includes;

(a) filter means having a plurality of color temperature conversion filters for converting the color temperature of said object including means for selecting one of said plurality of color temperature conversion filters; and

(b) means having a plurality of potential levels for adding one of said plurality of potential levels to said detection signal in response to the color temperatures conversion filter selected by said filter means.

8. A color television camera comprising:

(a) means for generating color signals of an object to be shot;

(b) detecting means for detecting a color temperature of alight illuminating said object and generating at least one color temperature signal in accordance with said detected color temperature;

(c) memory means for storing said color temperature signal and outputting said stored color temperature signal;

(d) setting means for controllably setting said color temperature signal in accordance with a predetermined color temperature and outputtting the same;

(e) control means responsive to said control temperature signal so as to control said color signals and thereby adjust the colors of a picture;

(f) selection means adapted to select one of an automatic, memory and standard control modes, said memory means transmitting said color temperature signal to said control means in response to the selection of said automatic control mode, said memory means storing said color temperature signal and outputting said color temperature signal to said control means in response to the selection of said memory control mode, and said setting means outputting the set color temperature signal to said control means in response to the selection of said standard control mode;

(g) power source means for energizing said camera; and

(h) change means responsive to said energizing of said camera by said power source means to change over said memory means to the automatic control mode irrespective of said memory control mode selected by said selection means.

9. A color television camera comprising:

(a) means for generating color signals of an object to be shot;

(b) detecting means for detecting a color temperature of a light illuminating said object and generating at least one color temperature signal in accordance with said detected color temperature;

(c) memory means for storing said color temperature signal and outputting the stored color temperature signal;

(d) setting means for controllably setting said color temperature signal in accordance with a predetermined color temperature and outputting the same;

(e) control means responsive to said color temperature signal so as to control said color signals and thereby adjust the colors of a picture;

(f) selection means adapted to select one of an automatic, memory and standard control modes, said memory means transmitting said color temperature signal to said control means in response to the selection of said automatic control mode, said memory means storing said color temperature signal and outputting said color temperature signal to said control means in response to the selection of said memory control mode, and said setting means outputting the set color temperature signal to said control means in response to the selection of said standard control mode;

(g) power source means for energizing said camera and deenergizing said camera; and

(h) change means responsive to said deenergizing of said camera by said power source means to change over said selection means to the first control mode when the second control mode has been selected.