Automatic white balance adjusting method of color video camera

Abstract

Abstract PURPOSE:To stabilize white balance even at the low intensity of illumination by adjusting the white balance in accordance with the chromatic temperature information of the peripheral light of an object, and when the brightness of the peripheral light becomes less than a prescribed value, adjusting the white balance by regarding the information as the prescribed value. CONSTITUTION:Output signals from red and blue light photodetector 1R, 1B to which the red and blue component signals of the peripheral light of the object are supplied are logarithmically compressed and then A/D converted and their digital signals are supplied to a microcomputer 4. Consequently, the microcomputer 4 detects the chromatic temperature information and the peripheral brightness of the object and controls the white balance. When the brightness of the peripheral light of the object is 100 luxes or less e.g., the microcomputer 4 sets up red and blue signal control signals corresponding to e.g. 3,200K chromatic temperature and controls the gains of red and blue signal gain control circuits 6R, 6B on the basis of said control signals so that the stable white balance is obtained. Until the intensity of the peripheral light reaches 100 luxes, said state is kept.

Inventors

• 👤 Norio Koyama
• 👤 紀男 小山

Bibliographic Details