Based On Ambient Light Patents (Class 348/366)
  • Patent number: 5486861
    Abstract: An electronic camera having an image sensor responsive to a preliminary exposure for producing an output signal, a computing circuit for computing a proper exposure condition on the basis of the signal, and a compensating circuit for compensating the exposure value in accordance with the proper exposure condition is provided with a compensation prohibiting circuit for prohibiting the exposure compensation by the preliminary exposure by taking into account the object condition and the exposure mode.
    Type: Grant
    Filed: October 20, 1994
    Date of Patent: January 23, 1996
    Assignee: Canon Kabushiki Kaisha
    Inventors: Ryosuke Miyamoto, Makoto Sekita, Shohei Takeda
  • Patent number: 5455685
    Abstract: Disclosed is an exposure control device for a video camera having automatic gain control by which both stability and instantaneous regulation of exposure can be satisfied in accordance with a photographing scene. The exposure control device for the video camera has an iris diaphragm control which receives an electric signal output an image sensor through a preamplifier as an iris diaphragm detection signal and which controls the iris diaphragm based on the iris diaphragm detection signal. An automatic gain control circuit receives an electric signal output from an automatic gain control amplifier disposed subsequent a preamplifier as an automatic gain control detection signal and controls the gain of the automatic gain control amplifier based on the automatic gain control detection signal. A determination circuit determines the various states of a photographing scene based on a change of an electric signal output the image sensor caused by lapse of time.
    Type: Grant
    Filed: August 31, 1992
    Date of Patent: October 3, 1995
    Assignee: Fuji Photo Film Co., Ltd.
    Inventor: Yoshihiko Mori