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AssigneeOlympus Optical Co., Ltd.
InventorsYoshihisa Maitani, Kunio Shimoyama, Muneaki Yoshida, Akihiko Hashimoto, Masahiro Kitagawa
Estimating the term…
A photometric apparatus for single lens reflex camera and of the type in which an exposure value is determined by photometry of light which is transmitted through a photographic optical system and is reflected by at least one of the surfaces of a shutter blind and a film, said apparatus comprising a photoelectric transducer element for receiving light reflected by at least one of the surfaces of a shutter blind and a film, and an operational amplifier for biasing the photoelectric transducer element to maintain the voltage applied thereacross substantially null, thereby enabling a photometric output of the photoelectric transducer element to be effectively derived even when the amount of light received is minimal. The shutter blind is provided with a surface upon which at least two portions thereof have different coefficients of reflectivity to reduce adverse effects of reflected light upon the desired exposure period.
A photometric apparatus for a single lens reflex camera and of the type in which an exposure value is determined by photometry of light which is transmitted through a photographic optical system and which is reflected by at least one of the surfaces of a shutter blind and a film, comprising a photoelectric transducer element for receiving reflected light from at least one of the surface of a shutter blind and a film, and an operational amplifier for biasing the transducer element so as to maintain the voltage applied thereacross substantially null the first blind of the shutter comprising a surface of high reflectivity which forms a light reflecting portion, and a surface of low reflectivity located at an area other than the light reflecting portion.
Dependencies are inferred from the claim text.