US 5,534,955 AGranted

Reflection type projector

AssigneeFuji Photo Film Co., Ltd.

InventorsMichiro Tuchida, Masaaki Nomura, Soichiro Kimura, Ko Aosaki, Tatsuo Kitami

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Abstract

A reflection prevention film coats a backside of a stage glass by a vacuum evaporation and coating, etc. A light from a metal halide lamp is not reflected on the back of the stage glass by the reflection preventing film, and is transmitted through the stage glass and is reflected on a surface of the stage glass and a transparent manuscript. The light reflected on the surface of the stage glass and the transparent manuscript enters a projection lens unit and appears as a spot light on a screen, but because the light is not reflected on the backside of the stage glass, so that the amount of the light, which causes the spot light, can be reduced. As a result, the spot light on the screen is inconspicuous.

Claims11

Dependent claims

A reflection type projector which comprises a housing wherein an opening formed on its upper surface is covered with a light transmission plate and a stage surface is formed on which a transparent manuscript is placed, a reflection Fresnel lens which is provided in said housing in such a manner to overlap said light transmission plate and holds said transparent manuscript between said stage surface and itself, a projection lens provided on a side of said housing, a light source which is provided in said housing and illuminates said transparent manuscript, and a reflection mirror which is provided in said housing and reflects a projection light of the transparent manuscript illuminated by said light source toward said projection lens, comprising:

a shutter member which is provided in such a manner that it can move forward onto and retract from an optical axis of said light source and advances onto said optical axis, thereby cutting off a projection light given to said transparent manuscript by said light source;
detecting means which detects whether said reflection Fresnel lens is opened or closed;
and,
drive means which advances said shutter member onto the optical axis of the light source on the basis of an information from said detecting means that said reflection Fresnel lens is opened and retracts the shutter member from the optical axis of the light source on the basis of an information from said detecting means that said reflection Fresnel lens is closed.

1 more element

Dependencies are inferred from the claim text.