Projection display device
First Claim
1. A projection display device comprising an illumination system having a light source and an optical guiding means having an entrance surface for entering light from the light source and an exit surface for providing an illumination beam, an image display system having a display panel for modulating the illumination beam with image information and projecting the image on a screen, and means for selectively transmitting a portion of the illumination beam having a desired characteristic to the image display system, and means for feeding back an unused portion of the illumination beam to the illumination system for re-illumination of the image display system, characterized in that a reflection means is provided at a portion of the entrance surface of the light-guiding means and the unused portion of the illumination beam is fed back into the light-guiding means.
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Accused Products
Abstract
The invention relates to a projection display device comprising an illumination system having a light source and an optical guiding means for providing an illumination beam, and an image display system for modulating the illumination beam with image information and projecting the image on a screen, and means for selectively transmitting a portion of the illumination beam having a desired characteristic to the image display system, and means for feeding back an unused portion of the illumination beam to the illumination system for re-illumination of the image display system. In order to improve the efficiency of the projection display device, a reflection means is provided at a portion of an entrance surface of the light-guiding means and the unused portion of the illumination beam is fed back into the light-guiding means.
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Citations
19 Claims
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1. A projection display device comprising
an illumination system having a light source and an optical guiding means having an entrance surface for entering light from the light source and an exit surface for providing an illumination beam, an image display system having a display panel for modulating the illumination beam with image information and projecting the image on a screen, and means for selectively transmitting a portion of the illumination beam having a desired characteristic to the image display system, and means for feeding back an unused portion of the illumination beam to the illumination system for re-illumination of the image display system, characterized in that a reflection means is provided at a portion of the entrance surface of the light-guiding means and the unused portion of the illumination beam is fed back into the light-guiding means.
Specification