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US5748376A
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High optical throughput liquid-crystal projection display system
Assignee: Industrial Technology Research Institute
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Filing: 1996-04-17
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Granted: 1998-05-05
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Expires: 2016-04-17
Abstract
Abstract A liquid-crystal projection display system with higher efficiency is provided. The liquid-crystal projection display system comprises a double-layer square-pillar-like integrator, including an inner layer and an outer layer, having a polarization-separating thin film formed between the inner layer and the outer layer. The system also includes a converging light source for generating light converged at a point near one end surface of the double-layer square-pillar-like integrator, so that most light emitted from the light source enters the double-layer square-pillar-like integrator, and different polarized light is transmitted by being totally reflected off of surfaces of the inner layer and the outer layer respectively. A first lens is provided for forming real light spots on an image plane from virtual light spots formed by totally reflecting the different polarized light transmitted in the double-layer square-pillar-like integrator. A polarization rotator is located at the image plane, for rotating one of the polarizations of the real light spots, while keeping another one of the polarizations unchanged, so that the polarization angles of all the real light spots are identical. A second lens is provided for evenly converging and projecting light beams from the light spots with an identical linear polarization to overlay on an object.
Inventors
- 👤 Kun-Wei Lin
- 👤 Han-Ping D. Shieh
- 👤 San-Ming Chen
- 👤 Kuang-Vu Chen
- 👤 Chong-Min Chang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 15:15
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1335; G02F1/1336; G02F1/13362; H; H04; H04N; H04N5/00; H04N5/74; H04N5/7416; H04N5/7441
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
182 words
A liquid-crystal projection display system, comprising: a double-layer square-pillar-like integrator, including an inner layer and an outer layer, having a polarization-separating thin film formed between the inner layer and the outer layer; a converging light source for generating light converged at a point near one end surface of the double-layer square-pillar-like integrator, so that most of the light emitted from the light source enters the double-layer square-pillar-like integrator, and different polarized light is transmitted by being totally reflected off of surfaces of the inner layer and the outer layer respectively; a first lens for forming real light spots on an image plane from virtual light spots formed by totally reflecting the different polarized light transmitted in the double-layer square-pillar-like integrator; a polarization rotator located at the image plane, for optionally rotating the polarization angle of the real light spots which have a certain polarization, so that the polarization angles of all the real light spots are identical; and a second lens for evenly converging and projecting light beams from the light spots with an identical linear polarization to overlay on an object.
Claim 2
Dependent Claim
182 words
A liquid-crystal projection display system, comprising: a double-layer square-pillar-like integrator, including an inner layer and an outer layer, having a polarization-separating thin film formed between the inner layer and the outer layer; a converging light source for generating light converged at a point near one end surface of the double-layer square-pillar-like integrator, so that most of the light emitted from the light source enters the double-layer square-pillar-like integrator, and different polarized light is transmitted by being totally reflected off of surfaces of the inner layer and the outer layer respectively; a first lens for forming real light spots on an image plane from virtual light spots formed by totally reflecting the different polarized light transmitted in the double-layer square-pillar-like integrator; a polarization rotator located at the image plane, for optionally rotating the polarization angle of the real light spots which have a certain polarization, so that the polarization angles of all the real light spots are identical; and a second lens for evenly converging and projecting light beams from the light spots with an identical linear polarization to overlay on an object.
Claim 3
Dependent Claim
17 words
A liquid-crystal projection display system as claimed in claim 1, wherein the object is an liquid-crystal panel.
Claim 4
Dependent Claim
21 words
A liquid-crystal projection display system as claimed in claim 1, wherein the polarization-separating thin film is an optical birefringent thin film.
Claim 5
Dependent Claim
28 words
A liquid-crystal projection display system as claimed in claim 1, wherein the polarization-separating thin film is coated thereon and is employed to separate P-polarized light and S-polarized light.
Claim 6
Dependent Claim
56 words
A liquid-crystal projection display system as claimed in claim 1, wherein the converging light source includes a light source and an elliptical reflecting mirror, the light source being positioned at one focus point of the elliptical reflecting mirror, so that light emitted from the light source converges at another focus point of the elliptical reflecting mirror.
Claim 7
Dependent Claim
44 words
A liquid-crystal projection display system as claimed in claim 1, wherein the polarization rotator is arranged corresponding to the light spots formed on the image plane, and rotates one of the polarizations to cause the light passing therethrough to be an identical linear polarization.
Claim 8
Dependent Claim
32 words
A liquid-crystal projection display system as claimed in claim 2, wherein the aspect ratio of cross section of the double-layer square-pillar-like integrator is equal to the aspect ratio of the liquid-crystal panel.
Claim 9
Dependent Claim
18 words
A liquid-crystal projection display system as claimed in claim 6, wherein the polarization rotator is arranged in blocks.
Claim 10
Dependent Claim
18 words
A liquid-crystal projection display system as claimed in claim 6, wherein the polarization rotator is made of liquid-crystal.
Claim 11
Dependent Claim
18 words
A liquid-crystal projection display system as claimed in claim 6, wherein the polarization rotator is made of mica.
Claim 12
Dependent Claim
24 words
A liquid-crystal projection display system as claimed in claim 7, wherein the aspect ratio of cross section of the double-layer square-pillar-like integrator is 16:9.
Claim 13
Dependent Claim
24 words
A liquid-crystal projection display system as claimed in claim 7, wherein the aspect ratio of cross section of the double-layer square-pillar-like integrator is 4:3.
References Cited (Backward Citations)
US4918583A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-05-04 | 2001-11-03 | 2002-05-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-05-04 | 2005-11-03 | 2006-05-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-05-04 | 2009-11-03 | 2010-05-05 | $7700.00 | Window Closed / Lapsed |