发明名称 Photometric apparatus for a camera
摘要 A camera is provided with automatic focusing circuitry which is arranged to begin to operate to drive a focusing motor, in response to an operation performed on a shutter release button, to bring the motor to a stop upon detection of an in-focus state and to produce an in-focus signal. Photometric circuitry is arranged to begin to operate in response to the operation on the release button to obtain a photometric value by detecting the luminance of an object to be photographed, and to be capable of renewing the photometric value in response to a change in the luminance of the object. The photometric value is locked in response to the generation of the in-focus signal. Control circuitry means which controls the photometric apparatus in response to cancellation of the operation on the release button. The control circuitry unlocks the photometric value kept at the photometric apparatus and allows the photometric apparatus to operate to obtain another photometric value by detecting the luminance of the object once more within a predetermined period of time.
申请公布号 US4926204(A) 申请公布日期 1990.05.15
申请号 US19890393115 申请日期 1989.08.04
申请人 CANON KABUSHIKI KAISHA 发明人 KAWAMURA, MASAHARU
分类号 G02B7/28;G02B7/36;G03B7/091;G03B7/28;G03B13/36 主分类号 G02B7/28
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