Television camera and white balance correcting method

• US 6,927,792 B1
• Filed: 03/13/2000
• Issued: 08/09/2005
• Est. Priority Date: 03/11/1999
• Status: Expired due to Fees

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Iwai, Nobuo, Mimura, Masakazu
• Primary Examiner(s): Garber, Wendy R.
• Assistant Examiner(s): MISLEH, JUSTIN P
• Application Number:
  US09/936,307
• Time in Patent Office: 1,975 Days
• Field of Search: H04/N00.5/238, H04/N00.5/243, H04/N00.5/335, H04/N00.9/097, 348/223.1, 348/224.1, 348/225.1, 348/262, 348/263, 348/264, 348/265, 348/336, 348/337, 348/338
• US Class Current: 348/223.1
• CPC Class Codes: H04N 23/88 for colour balance, e.g. white-balance circuits or colour temperature control

Abstract

The white balance of a television camera is not lost and kept properly even if the diaphragm is opened to the utmost limit at a dark place. A signal F representing the diaphragm value of the taking lens is inputted from an iris part 2 into a microcomputer 8. The level adjusting values of the R, G, and B signals are set in the microcomputer 8 according to the diaphragm signal F and sent to a white balance correcting circuit 6. The correcting circuit 6 adjusts the levels of the R, G, and B signals to the same value according to the level adjusting values.

Claims

1. A television camera which adjusts levels of R, G, and B signals obtained through a three-color separation optical system to maintain white balance, said television camera comprising:

an iris section for performing an opening/closing operation of a diaphragm of a taking lens, and outputting a diaphragm signal indicating an opening condition of the diaphragm;

a microcomputer for inputting the diaphragm signal from the iris section, and setting level adjusting values of the R, G, and B signals; and

white balance correcting means for adjusting levels of the R, G, and B signals according to the level adjusting values,

wherein said white balance correcting means has three analog multipliers for multiplying individually the R, G, and B signals before being white balance corrected with multiplying coefficients thereto, and outputting individually the individually multiplied values as the R, G, and B signals after being white balance corrected,

wherein said microcomputer stores the multiplying coefficients as said level adjusting values by bringing the multiplying coefficients into correspondence with a whole of diaphragm regions of the taking lens,

wherein in a condition in which the diaphragm of the taking lens is not opened near to an opening end, said microcomputer outputs said stored multiplying coefficients to said analog multipliers,

wherein in a condition in which the diaphragm of the taking lens is opened near to the opening end, said microcomputer sets individually said multiplying coefficients in such a manner that a level of at least one arbitrary signal of the R, G, and B signals is made substantially even to that of at least one of other R, G, and B signals, and outputs said individually set multiplying coefficients to said analog multipliers,

wherein setting level adjusting values of the R, G, and B signals and level adjusting according to said setting are performed in response to a change in the diaphragm condition of said taking lens, and

wherein said at least one arbitrary signal is the signal G.

2. A television camera which adjusts levels of R, G, and B signals obtained through a three-color separation optical system to maintain white balance, said television camera comprising:

an iris section for performing an opening/closing operation of a diaphragm of a taking lens, and outputting a diaphragm signal indicating an opening condition of the diaphragm;

a microcomputer for inputting the diaphragm signal from the iris section, and setting level adjusting values of the R, G, and B signals; and

white balance correcting means for adjusting levels of the R, G, and B signals according to the level adjusting values,

wherein said white balance correcting means has three analog multipliers for multiplying individually the R, G, and B signals before being white balance corrected with multiplying coefficients thereto, and outputting individually the individually multiplied values as the R, G, and B signals after being white balance corrected,

wherein said microcomputer stores the multiplying coefficients as said level adjusting values by bringing the multiplying coefficients into correspondence with a whole of diaphragm regions of the taking lens,

wherein in a condition in which the diaphragm of the taking lens is not opened near to an opening end, said microcomputer outputs said stored multiplying coefficients to said analog multipliers,

wherein in a condition in which the diaphragm of the taking lens is opened near to the opening end, said microcomputer sets individually said multiplying coefficients in such a manner that a level of at least one arbitrary signal of the R, G, and B signals is made substantially even to that of at least one of other R, G, and B signals, and outputs said individually set multiplying coefficients to said analog multipliers,

wherein setting level adjusting values of the R, G, and B signals and level adjusting according to said setting are performed in response to a change in the diaphragm condition of said taking lens, and

wherein said at least one arbitrary signal is the signal R.

3. A television camera which adjusts levels of R, G, and B signals obtained through a three-color separation optical system to maintain white balance, said television camera comprising:

an iris section for performing an opening/closing operation of a diaphragm of a taking lens, and outputting a diaphragm signal indicating an opening condition of the diaphragm;

a microcomputer for inputting the diaphragm signal from the iris section, and setting level adjusting values of the R, G, and B signals; and

white balance correcting means for adjusting levels of the R, G, and B signals according to the level adjusting values,

wherein said white balance correcting means has three analog multipliers for multiplying individually the R, G, and B signals before being white balance corrected with multiplying coefficients thereto, and outputting individually the individually multiplied values as the R, G, and B signals after being white balance corrected,

wherein said microcomputer stores the multiplying coefficients as said level adjusting values by bringing the multiplying coefficients into correspondence with a whole of diaphragm regions of the taking lens,

wherein in a condition in which the diaphragm of the taking lens is not opened near to an opening end, said microcomputer outputs said stored multiplying coefficients to said analog multipliers,

wherein in a condition in which the diaphragm of the taking lens is opened near to the opening end, said microcomputer sets individually said multiplying coefficients in such a manner that a level of at least one arbitrary signal of the R, G, and B signals is made substantially even to that of at least one of other R, G, and B signals, and outputs said individually set multiplying coefficients to said analog multipliers,

wherein setting level adjusting values of the R, G, and B signals and level adjusting according to said setting are performed in response to a change in the diaphragm condition of said taking lens, and

wherein said at least one arbitrary signal is the signal B.

4. A television camera which adjusts levels of R, G, and B signals obtained through a three-color separation optical system to maintain white balance, said television camera comprising:

an iris section for performing an opening/closing operation of a diaphragm of a taking lens, and outputting a diaphragm signal indicating an opening condition of the diaphragm;

a microcomputer for inputting the diaphragm signal from the iris section, and setting level adjusting values of the R, G, and B signals; and

white balance correcting means for adjusting levels of the R, G, and B signals according to the level adjusting values,

wherein said white balance correcting means has three analog multipliers for multiplying individually the R, G, and B signals before being white balance corrected with multiplying coefficients thereto, and outputting individually the individually multiplied values as the R, G, and B signals after being white balance corrected,

wherein said microcomputer stores the multiplying coefficients as said level adjusting values by bringing the multiplying coefficients into correspondence with a whole of diaphragm regions of the taking lens,

wherein in a condition in which the diaphragm of the taking lens is not opened near to an opening end, said microcomputer outputs said stored multiplying coefficients to said analog multipliers,

wherein in a condition in which the diaphragm of the taking lens is opened near to the opening end, said microcomputer sets individually said multiplying coefficients in such a manner that a level of at least one arbitrary signal of the R, G, and B signals is made substantially even to that of at least one of other R, G, and B signals, and outputs said individually set multiplying coefficients to said analog multipliers,

wherein setting level adjusting values of the R, G, and B signals and level adjusting according to said setting are performed in response to a change in the diaphragm condition of said taking lens.

5. A television camera which adjusts levels of R, G, and B signals obtained through a three-color separation optical system to maintain white balance, said television camera comprising:

an iris section for performing an opening/closing operation of a diaphragm of a taking lens, and outputting a diaphragm signal indicating an opening condition of the diaphragm;

a microcomputer for inputting the diaphragm signal from the iris section, and setting level adjusting values of the R, G, and B signals; and

white balance correcting means for adjusting levels of the R, G, and B signals according to the level adjusting values,

wherein said white balance correcting means has three analog multipliers for multiplying individually the R, G, and B signals before being white balance corrected with multiplying coefficients thereto, and outputting individually the individually multiplied values as the R, G, and B signals after being white balance corrected,

wherein said microcomputer stores the multiplying coefficients as said level adjusting values by bringing the multiplying coefficients into correspondence with a whole of diaphragm regions of the taking lens,

wherein in a condition in which the diaphragm of the taking lens is not opened near to an opening end, said microcomputer outputs said stored multiplying coefficients to said analog multipliers,

wherein in a condition in which the diaphragm of the taking lens is opened near to the opening end, said microcomputer sets individually said multiplying coefficients in such a manner that a level of at least one arbitrary signal of the R, G, and B signals is made substantially even to that of at least one of other R, G, and B signals, and outputs said individually set multiplying coefficients to said analog multipliers.

6. A television camera white balance correcting method for adjusting levels of R, G, and B signals obtained through a three-color separation optical system to maintain white balance, said television camera white balance correcting method comprising the steps of:

a) performing an opening/closing operation of a diaphragm of a taking lens, and outputting a diaphragm signal indicating an opening condition of the diaphragm;

b) inputting the diaphragm signal from the step a) into a microcomputer, said microcomputer operative to set level adjusting values of the R, G, and B signals;

c) adjusting the levels of the R, G, and B signals according to the level adjusting values;

d) multiplying individually the R, G, and B signals before being white balance corrected with multiplying coefficients thereto, and outputting individually the individually multiplied values as the R, G, and B signals after being white balance corrected; and

e) storing the multiplying coefficients as said level adjusting values by bringing the multiplying coefficients into correspondence with a whole of diaphragm regions of the taking lens,

wherein in a condition in which the diaphragm of the lens is not opened near to an opening end, said microcomputer outputs said stored multiplying coefficients, and

wherein in a condition in which the diaphragm of the lens is opened near to the opening end, said microcomputer sets individually said multiplying coefficients in such a manner that a level of at least one arbitrary signal of the R, G, and B signals is made substantially even to that of at least one of other R, G, and B signals.

7. A television camera white balance correcting method for adjusting levels of R, G, and B signals obtained through a three-color separation optical system to maintain white balance, said television camera white balance correcting method comprising the steps of:

a) performing an opening/closing operation of a diaphragm of a taking lens, and outputting a diaphragm signal indicating an opening condition of the diaphragm;

b) inputting the diaphragm signal from the step a) into a microcomputer, said microcomputer operative to set level adjusting values of the R, G, and B signals;

c) adjusting the levels of the R, G, and B signals according to the level adjusting values;

d) multiplying individually the R, G, and B signals before being white balance corrected with multiplying coefficients thereto, and outputting individually the individually multiplied values as the R, G, and B signals after being white balance corrected; and

e) storing the multiplying coefficients as said level adjusting values by bringing the multiplying coefficients into correspondence with a whole of diaphragm regions of the taking lens,

wherein in a condition in which the diaphragm of the lens is not opened near to an opening end, said microcomputer outputs said stored multiplying coefficients, and

wherein in a condition in which the diaphragm of the lens is opened near to the opening end, said microcomputer sets individually said multiplying coefficients in such a manner that a level of at least one arbitrary signal of the R, G, and B signals is made substantially even to that of at least one of other R, G, and B signals,

wherein setting level adjusting values of the R, G, and B signals and level adjusting according to said setting are performed in response to a change in the diaphragm condition of said taking lens, and

wherein said at least one arbitrary signal is the signal G.

8. A television camera white balance correcting method for adjusting levels of R, G, and B signals obtained through a three-color separation optical system to maintain white balance, said television camera white balance correcting method comprising the steps of:

a) performing an opening/closing operation of a diaphragm of a taking lens, and outputting a diaphragm signal indicating an opening condition of the diaphragm;

b) inputting the diaphragm signal from the step a) into a microcomputer, said microcomputer operative to set level adjusting values of the R, G, and B signals;

c) adjusting the levels of the R, G, and B signals according to the level adjusting values;

d) multiplying individually the R, G, and B signals before being white balance corrected with multiplying coefficients thereto, and outputting individually the individually multiplied values as the R, G, and B signals after being white balance corrected; and

e) storing the multiplying coefficients as said level adjusting values by bringing the multiplying coefficients into correspondence with a whole of diaphragm regions of the taking lens,

wherein in a condition in which the diaphragm of the lens is not opened near to an opening end, said microcomputer outputs said stored multiplying coefficients, and

wherein in a condition in which the diaphragm of the lens is opened near to the opening end, said microcomputer sets individually said multiplying coefficients in such a manner that a level of at least one arbitrary signal of the R, G, and B signals is made substantially even to that of at least one of other R, G, and B signals,

wherein setting level adjusting values of the R, G, and B signals and level adjusting according to said setting are performed in response to a change in the diaphragm condition of said taking lens, and

wherein said at least one arbitrary signal is the signal R.

9. A television camera white balance correcting method for adjusting levels of R, G, and B signals obtained through a three-color separation optical system to maintain white balance, said television camera white balance correcting method comprising the steps of:

a) performing an opening/closing operation of a diaphragm of a taking lens, and outputting a diaphragm signal indicating an opening condition of the diaphragm;

b) inputting the diaphragm signal from the step a) into a microcomputer, said microcomputer operative to set level adjusting values of the R, G, and B signals;

c) adjusting the levels of the R, G, and B signals according to the level adjusting values;

d) multiplying individually the R, G, and B signals before being white balance corrected with multiplying coefficients thereto, and outputting individually the individually multiplied values as the R, G, and B signals after being white balance corrected; and

e) storing the multiplying coefficients as said level adjusting values by bringing the multiplying coefficients into correspondence with a whole of diaphragm regions of the taking lens,

wherein in a condition in which the diaphragm of the lens is not opened near to an opening end, said microcomputer outputs said stored multiplying coefficients, and

wherein in a condition in which the diaphragm of the lens is opened near to the opening end, said microcomputer sets individually said multiplying coefficients in such a manner that a level of at least one arbitrary signal of the R, G, and B signals is made substantially even to that of at least one of other R, G, and B signals,

wherein setting level adjusting values of the R, G, and B signals and level adjusting according to said setting are performed in response to a change in the diaphragm condition of said taking lens, and

wherein said at least one arbitrary signal is the signal B.

10. A television camera white balance correcting method for adjusting levels of R, G, and B signals obtained through a three-color separation optical system to maintain white balance, said television camera white balance correcting method comprising the steps of:

a) performing an opening/closing operation of a diaphragm of a taking lens, and outputting a diaphragm signal indicating an opening condition of the diaphragm;

b) inputting the diaphragm signal from the step a) into a microcomputer, said microcomputer operative to set level adjusting values of the R, G, and B signals;

c) adjusting the levels of the R, G, and B signals according to the level adjusting values;

d) multiplying individually the R, G, and B signals before being white balance corrected with multiplying coefficients thereto, and outputting individually the individually multiplied values as the R, G, and B signals after being white balance corrected; and

e) storing the multiplying coefficients as said level adjusting values by bringing the multiplying coefficients into correspondence with a whole of diaphragm regions of the taking lens,

wherein in a condition in which the diaphragm of the lens is not opened near to an opening end, said microcomputer outputs said stored multiplying coefficients, and

wherein in a condition in which the diaphragm of the lens is opened near to the opening end, said microcomputer sets individually said multiplying coefficients in such a manner that a level of at least one arbitrary signal of the R, G, and B signals is made substantially even to that of at least one of other R, G, and B signals,

wherein setting level adjusting values of the R, G, and B signals and level adjusting according to said setting are performed in response to a change in the diaphragm condition of said taking lens.