Automatic exposure control circuit for camera
AssigneeOlympus Optical Co., Ltd.
InventorMasahiro Kitagawa
Life of this patent
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Abstract
An automatic exposure control circuit for camera having the capability to control the amount of light emitted by a flash discharge tube of an electronic flash comprises bias current booster means which becomes operative as the flash discharge tubes begins to emit light, thereby increasing the speed of response of the control circuit without increasing an input current thereto.
Claims7
An automatic exposure control circuit for a camera having the capability to control the amount of light emitted by a flash discharge tube of an electronic flash;
- characterized by the provision of bias current booster means for increasing the speed of response of said control circuit as the flash discharge tube begins to emit light.
An automatic exposure control circuit for controlling an electronic flash circuit having a flash discharge tube comprising:
- sensing means for generating a signal representing the amount of light reflected from an object illuminated by said flash discharge tube to generate;
- means for comparing the signal generated by said sensing means against an adjustable level for extinguishing said flash discharge tube;
- said comparing means comprising control means for controlling the response time of said comparing means;
- and
- booster voltage means responsive to operation of said flash discharge tube to apply a voltage to said control means for increasing the response time of said comparing means responsive to illumination of the flash discharge tube.
Dependencies are inferred from the claim text.