Invention Grant
- Patent Title: Folding converging light into a lightpipe
- Patent Title (中): 将会聚光折叠成光管
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Application No.: US10917054Application Date: 2004-08-12
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Publication No.: US07252399B2Publication Date: 2007-08-07
- Inventor: John Ferri , Michael Newell , Clark Pentico
- Applicant: John Ferri , Michael Newell , Clark Pentico
- Applicant Address: US CA Milpitas
- Assignee: JDS Uniphase Corporation
- Current Assignee: JDS Uniphase Corporation
- Current Assignee Address: US CA Milpitas
- Agency: Allen, Dyer, Doppelt, Milbrath & Gilchrist, P.A.
- Main IPC: F21V9/14
- IPC: F21V9/14

Abstract:
The present invention relates to a folded front end unit used in a light engine of a projection display device. The front end unit comprises a light source for generating a beam of light, and a lightpipe for providing spatial uniformity to the beam of light. Polarization-dependent front end units include polarization beam splitters for separating the light into orthogonally polarized sub-beams, and a polarization rotating element, e.g. a waveplate, for rotating the polarization of one of the sub-beams. In accordance with the present invention, a prism is positioned between the light source and the lightpipe for reflecting the light into the lightpipe. The difference in refractive index between the air and the prism decreases the cone angle of the beam of light enough to effectively increase the distance between the light source and the lightpipe to compensate for the added distance required to fold the light.
Public/Granted literature
- US20050036203A1 Folding converging light into a lightpipe Public/Granted day:2005-02-17
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