Solid state based illumination source for a projection display
First Claim
1. An illumination source comprising:
- a light source;
a collector for collecting light from said light source and illuminating an exit aperture therewith, said collector comprising a non-imaging optical element;
an imaging optical element for imaging said exit aperture onto a surface; and
a partially reflecting film located between said exit aperture and said imaging optical element, said partially reflecting film reflecting light of a first polarization state back into said collector and transmitting light of an orthogonal polarization state.
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0 Petitions
Accused Products
Abstract
An illumination source for use in projectors and the like. The illumination source includes a light source that generates a two-dimensional emission pattern having a light intensity that varies as a function of position in the emission pattern. A collector collects the light from the light source and illuminates an exit aperture therewith. The illuminated exit aperture has a two-dimensional emission pattern with a light intensity that varies as a function of position in a manner that is more uniform as a function of position than the emission pattern of the light source. An imaging optical element images the exit aperture onto a surface. The collector is preferably a compound parabolic concentrator or a compound elliptical concentrator. In one embodiment of the invention, a partially reflecting film is placed between the exit aperture and the imaging optical element. The partially reflecting film reflects light of a first polarization state back into the collector and transmits light of the orthogonal polarization state. In another embodiment of the invention, a quarter wave plate is introduced between the exit aperture and the partially reflecting film to further increase the radiance of the source.
56 Citations
2 Claims
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1. An illumination source comprising:
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a light source;
a collector for collecting light from said light source and illuminating an exit aperture therewith, said collector comprising a non-imaging optical element;
an imaging optical element for imaging said exit aperture onto a surface; and
a partially reflecting film located between said exit aperture and said imaging optical element, said partially reflecting film reflecting light of a first polarization state back into said collector and transmitting light of an orthogonal polarization state. - View Dependent Claims (2)
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Specification
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- Resources
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Current AssigneeAvago Technologies ECBU IP Singapore Pte Limited (Broadcom, Inc.)
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Original AssigneeAgilent Technologies, Inc.
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InventorsWilliamson, James B., Weber, Andreas G., Cutler, Gregory M.
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Primary Examiner(s)Metjahic, Safet
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Assistant Examiner(s)LEROUX, ETIENNE PIERRE
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Application NumberUS09/240,198Time in Patent Office1,159 DaysField of Search353/30, 353/31, 353/34, 353/37, 353/82, 353/20, 353/98, 349/5, 349/9, 359/196, 359/204, 359/208, 359/385, 359/386, 359/483, 359/487, 359/488, 359/490US Class Current353/30CPC Class CodesG03B 21/2033 LED or laser light sourcesG03B 21/2073 Polarisers in the lamp hous...H04N 5/74 Projection arrangements for...
