Patent
1992-08-18
1994-07-26
Perkey, W. B.
354200, 354219, G03B 1302
Patent
active
053330315
ABSTRACT:
A diffusion degree of a focusing screen is changed by applying voltage to the focusing screen since the focusing screen comprises liquid crystal material whose molecules are penetrated onto a polymer network. The diffusion degree is changed according to the selected exposure mode. Brightness of an object, measured through the focusing screen, is corrected on the basis of applied voltage, an open aperture value and an exit pupil length of a photo-taking lens. Furthermore, the applied voltage, namely, the diffusion degree is changed according to the object brightness.
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Minolta Camera Kabushiki Kaisha
Perkey W. B.
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