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US 6,204,901 B1Granted
Liquid crystal color shutters that include reflective polarizers that pass color components of light of a first polarization and that reflect a majority of color components of light of a second polarization
AssigneeDuke University
InventorRichard M. Knox
Life of this patent
Estimating the term…
Abstract
Color shutters that include reflecting linear polarizers can be used in projection display applications. The reflecting linear polarizers are used to reflect the light that would have been absorbed by prior art color shutters. The use of reflecting linear polarizers can resolve overheating and degradation problems of prior art system and projection display systems using sequential color operation can be built and operate reliably.
Claims29
An apparatus comprising:
- a liquid crystal color shutter that sequentially filters different color components of light, the liquid crystal color shutter including a reflecting polarizer that passes first color components of light having a first polarization to provide the first color components to an image surface that is spaced apart from the liquid crystal color shutter and that reflects a majority of second color components of light having a second polarization that is different than the first polarization.
A liquid crystal color shutter that sequentially filters different color components of light, comprising:
- a reflecting polarizer, positioned in the liquid crystal color shutter, that sequentially passes first color components of light having a first polarization to provide the first color components to an image surface that is spaced apart from the liquid crystal color shutter and that reflects a majority of second color components of light having a second polarization that is different than the first polarization;
- and
- an active retarder, positioned in the liquid crystal color shutter, that retards the first color components of light in a first operating state and retards the second color components of light in a second operating state.
Dependencies are inferred from the claim text.