Patent
1981-03-23
1982-07-13
Griffin, Donald A.
354200, G03B 1302, G03B 300
Patent
active
043391885
ABSTRACT:
A twin lens reflex camera has a viewing system including a ground glass screen having the viewing surface coated with a thin layer of a clear optical grade epoxy and has the coated surface mounted behind and in contact with a Fresnel lens. A pair of magnifying lenses are positioned behind the ground glass screen in front of the viewing station. The coating is applied while in solution with solvents that thereafter evaporate. A final thickness of approximately 0.0001 inch is obtained by further processing. An improvement of received image brightness of approximately 8 to 25 fold uniformly over the image screen has been measured. The magnifying lenses are adjustably mounted within the interior of the viewer to improve eye relief. A flexible hood readily adjustable on the viewer housing cooperates with adjustable flaps secured to the viewer housing to provide good contrast to the image formed on the screen.
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Beattie Systems, Inc.
Griffin Donald A.
Ruderman Alan
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