US6204901B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
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
Assignee: Duke University
•
Filing: 1998-07-07
•
Granted: 2001-03-20
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Expires: 2018-07-07
Abstract
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.
Inventors
- 👤 Richard M. Knox
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 14:46
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1347; G02F1/13471; G02F1/13473; H; H04; H04N; H04N5/00; H04N5/74; G21; G21K; G21K1/00; G21K1/02; G21K1/04; G02F1/1335; G02F1/133528; G02F1/133536; G02F1/133545
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
78 words
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.
Claim 2
Independent Claim
78 words
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.
Claim 3
Dependent Claim
15 words
The apparatus of claim 1 , wherein the reflecting polarizer comprises a reflecting linear polarizer.
Claim 4
Dependent Claim
41 words
The apparatus of claim 1 , wherein the color shutter further comprises an active retarder that retards the first color components of light in a first operating state and that retards the second components of light in a second operating state.
Claim 5
Dependent Claim
15 words
The apparatus of claim 1 , wherein the color shutter further comprises a clean-up polarizer.
Claim 6
Dependent Claim
24 words
The apparatus of claim 1 , wherein the reflecting polarizer comprises an entrance polarizer and the color shutter further comprises an exit reflecting polarizer.
Claim 7
Dependent Claim
15 words
The apparatus of claim 5 , wherein the exit reflecting polarizer comprises a clean-up polarizer.
Claim 8
Dependent Claim
14 words
The apparatus of claim 1 , wherein the reflecting polarizer comprises multilayer optical film.
Claim 9
Dependent Claim
25 words
The apparatus of claim 1 , wherein the color shutter comprises a plurality of reflecting polarizers adapted to retard light passing through the color shutter.
Claim 10
Dependent Claim
16 words
The apparatus of claim 1 , wherein the reflecting polarizer comprises a substantially nonabsorbing reflecting polarizer.
Claim 11
Dependent Claim
22 words
The apparatus of claim 1 , wherein the reflecting polarizer passes light through the liquid crystal color shutter to distrubute thermal energy.
Claim 12
Dependent Claim
18 words
The apparatus of claim 1 , wherein the reflecting polarizer reflects light from the liquid crystal color shutter.
Claim 13
Dependent Claim
17 words
The apparatus of claim 1 , wherein the color shutter is comprised in a tunable optical filter.
Claim 14
Dependent Claim
18 words
The apparatus of claim 1 , wherein the color shutter further comprises stages including a reflecting polarizer stage.
Claim 15
Dependent Claim
20 words
The apparatus of claim 1 , wherein the color shutter further comprises part of a field sequential color display system.
Claim 16
Dependent Claim
115 words
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.
Claim 17
Dependent Claim
115 words
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.
Claim 18
Dependent Claim
36 words
The color shutter of claim 15 , wherein the color shutter further comprises a passive retarder adapted to impart a fixed retardation on one of light of the polarization and light retarded by the active retarder.
Claim 19
Dependent Claim
15 words
The color shutter of claim 16 , wherein the passive retarder comprises a birefringent element.
Claim 20
Dependent Claim
16 words
The color shutter of claim 15 , wherein the reflecting polarizer comprises a reflecting linear polarizer.
Claim 21
Dependent Claim
15 words
The color shutter of claim 15 , wherein the reflecting polarizer comprises multilayer optical film.
Claim 22
Dependent Claim
15 words
The color shutter of claim 15 , wherein the active retarder comprises ferroelectric liquid crystals.
Claim 23
Dependent Claim
20 words
The color shutter of claim 15 , wherein the different operating states of the active retarder comprise discrete operating states.
Claim 24
Dependent Claim
20 words
The color shutter of claim 15 , wherein the different operating states of the active retarder comprise continuous operating states.
Claim 25
Dependent Claim
15 words
The color shutter of claim 15 , wherein the reflecting polarizer comprises a nonabsorbing polarizer.
Claim 26
Dependent Claim
16 words
The color shutter of claim 15 , wherein the reflecting polarizer comprises a substantially nonabsorbing polarizer.
Claim 27
Dependent Claim
19 words
The color shutter of claim 15 , further comprising a clean-up polarizer adapted to work with the reflecting polarizer.
Claim 28
Dependent Claim
16 words
The color shutter of claim 25 , wherein the clean-up polarizer comprises an absorptive linear polarizer.
Claim 29
Dependent Claim
30 words
The color shutter of claim 15 , further comprising stages, wherein each stage is defined by a plurality of reflecting polarizers and each stages comprises a plurality of active retarders.
Claim 30
Dependent Claim
24 words
The color shutter of claim 15 , wherein the reflecting polarizer and the active retarder comprise part of a field sequential color display system.
Claim 31
Dependent Claim
15 words
The projection system of claim 15 , wherein the reflecting polarizer comprises multiplayer optical film.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2004-03-19 | 2004-09-18 | 2005-03-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-03-19 | 2008-09-18 | 2009-03-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-03-19 | 2012-09-18 | 2013-03-20 | $7700.00 | Window Closed / Lapsed |