Polarization independent liquid crystal-based etalon and devices using same
First Claim
1. A liquid crystal etalon comprising:
- a chiral nematic material;
a liquid crystal cell containing the chiral nematic material and having one or more alignment surfaces configured to urge the chiral nematic material toward a twisted liquid crystal configuration having a twist of greater than 90 degrees and less than 360 degrees;
electrodes operatively coupled with the liquid crystal cell to apply an operative electrical bias to the liquid crystal cell; and
mirrors disposed about the chiral nematic material to define a resonant optical cavity;
wherein the etalon provides substantially polarization independent transmission of light at a first wavelength at a first operative electrical bias applied by the electrodes that does not substantially unwind the twisted liquid crystal configuration.
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Accused Products
Abstract
A liquid crystal etalon includes a chiral nematic material contained in a liquid crystal cell having alignment surfaces configured to bias the chiral nematic material toward a twisted liquid crystal configuration with a twist less than 360°. Electrodes are arranged to apply an operative electrical bias to the liquid crystal cell. Mirrors disposed about the chiral nematic material define a resonant optical cavity. At a first electrical bias the etalon is transmissive for light of a first wavelength via a selected liquid crystal twist angle and cavity thickness at which different non-equal eigenmodes reach resonance conditions simultaneously. In a projector embodiment, a projection system with a field sequential image projection light source is coupled with the liquid crystal etalon, the etalon electrodes are patterned into pixels defining a display area, and the projector is operated in a field sequential illumination mode.
10 Citations
29 Claims
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1. A liquid crystal etalon comprising:
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a chiral nematic material; a liquid crystal cell containing the chiral nematic material and having one or more alignment surfaces configured to urge the chiral nematic material toward a twisted liquid crystal configuration having a twist of greater than 90 degrees and less than 360 degrees; electrodes operatively coupled with the liquid crystal cell to apply an operative electrical bias to the liquid crystal cell; and mirrors disposed about the chiral nematic material to define a resonant optical cavity; wherein the etalon provides substantially polarization independent transmission of light at a first wavelength at a first operative electrical bias applied by the electrodes that does not substantially unwind the twisted liquid crystal configuration. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A liquid crystal etalon comprising:
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a liquid crystal material; a liquid crystal cell containing the liquid crystal material and urging the liquid crystal material toward a twisted liquid crystal configuration having a twist greater than 90 degrees and less than 360 degrees; electrodes operatively coupled with the liquid crystal cell to electrically bias the liquid crystal cell; and mirrors disposed about the liquid crystal material to define a resonant optical cavity; wherein the liquid crystal material and the liquid crystal cell are configured to define a first operational state at a first electrical bias in which the liquid crystal material has a twisted liquid crystal configuration having a twist greater than 90° and
the etalon is transmissive for light of a first wavelength via first and second etalon eigenmodes of different etalon orders. - View Dependent Claims (10, 11, 12, 13, 14, 15)
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16. A liquid crystal etalon comprising:
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a liquid crystal material; a liquid crystal cell containing the liquid crystal material and urging the liquid crystal material toward a twisted liquid crystal configuration; electrodes operatively coupled with the liquid crystal cell to electrically bias the liquid crystal cell; and mirrors disposed about the liquid crystal material to define a resonant optical cavity; the liquid crystal material and the liquid crystal cell being configured to define a first operational state at a first electrical bias in which the etalon exhibits at least about 90% transmittance for unpolarized light of a first wavelength, the liquid crystal material having a first twisted liquid crystal configuration at the first electrical bias. - View Dependent Claims (17, 18, 19, 20, 21, 22)
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23. An image generating device comprising:
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an etalon including; a liquid crystal material, a liquid crystal cell containing the liquid crystal material and urging the liquid crystal material toward a twisted liquid crystal configuration, and electrodes operatively coupled with the liquid crystal cell to electrically bias the liquid crystal cell, the electrodes of the etalon defining an array of pixels, wherein pixels are switchable by a first electrical bias into a first operational state in which the pixel is transmissive for light of a first wavelength, and are switchable by a second electrical bias into a second operational state in which the pixel is transmissive for light of a second wavelength, and wherein the pixels are transmissive for light of a third wavelength in one of the first and second operational states; and a controller electrically communicating with the electrodes to switch pixels between the first and second operational states in synchronization with field sequential illumination having illumination sub-cycles corresponding to the first, second, and third wavelengths in order to generate a color display. - View Dependent Claims (24, 25, 26, 27, 28, 29)
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Specification