Optical: systems and elements – Polarization without modulation
Patent
1995-12-20
1999-03-30
Hellner, Mark
Optical: systems and elements
Polarization without modulation
349 6, 353 20, G02B 0530, G03B 2114
Patent
active
058896147
ABSTRACT:
A presentation system comprising an image projection screen and an overhead projector is described. The overhead projector comprises an illumination system, a support for supporting an image record carrier and a projection head for projecting the image present in the image record carrier on the image projection screen. The image projection screen is a polarizing screen which transmits radiation having a well-defined direction of transmission polarization, and the overhead projector is adapted to supply light having this direction of polarization. In this way, the quantity of radiation used for forming the image is considerably increased and substantially half the quantity of ambient light incident on the screen is suppressed, so that images having a considerably enhanced contrast and brightness are obtained.
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Cobben Louis M. H.
Stroomer Martinus V. C.
Faller F. Brice
Hellner Mark
U.S. Philips Corporation
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