Patent US4621294A successfully refreshed from Google Patents.
US4621294A
Expired / Lapsed
US
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Contrast enhancing optical coupling pad for projection TV
Assignee: Zenith Electronics LLC
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Filing: 1984-03-30
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Granted: 1986-11-04
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Expires: 2004-03-30
Abstract
Abstract An image projection system using a projection type cathode ray tube and lens element. The improvement being a direct optical coupling between the display surface and the lens element comprised of a transparent, compressible, multi-layer, resin formulated pad wherein the outer layer of the pad are peelable.
Inventors
- 👤 Sae D. Lee
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 13:40
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/74; H04N5/7408
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
159 words
In an image projection system comprising a projection type cathode ray tube for developing an image upon a display surface associated therewith, and an optical projector comprising a lens having an entrance element, the central axis of which is substantially coincident with the axis of said display surface, for projecting an aerial image of said developed image to a viewing screen, the improvement for enhancing the contrast of said projected image comprising: means for effecting a direct optical coupling between said display surface of said tube and said lens element comprising a transparent, compressible, multi-layer, resin formulated pad for providing a close index of refraction match between said display surface and said lens element, said pad having a first outer peelable layer disposed in intimate contact with said image display surface and a second outer peelable layer disposed in intimate contact with said lens element to substantially preclude an air gap between said display surface and said lens element.
Claim 2
Dependent Claim
159 words
In an image projection system comprising a projection type cathode ray tube for developing an image upon a display surface associated therewith, and an optical projector comprising a lens having an entrance element, the central axis of which is substantially coincident with the axis of said display surface, for projecting an aerial image of said developed image to a viewing screen, the improvement for enhancing the contrast of said projected image comprising: means for effecting a direct optical coupling between said display surface of said tube and said lens element comprising a transparent, compressible, multi-layer, resin formulated pad for providing a close index of refraction match between said display surface and said lens element, said pad having a first outer peelable layer disposed in intimate contact with said image display surface and a second outer peelable layer disposed in intimate contact with said lens element to substantially preclude an air gap between said display surface and said lens element.
Claim 3
Dependent Claim
19 words
The improvement set forth in claim 1 in which said pad has an index of refraction of approximately 1.41.
Claim 4
Dependent Claim
27 words
The improvement set forth in claim 1 in which said pad has a compressibility of approximately 0.50 mm for an overall pad thickness of approximately 4.5 mm.
Claim 5
Dependent Claim
73 words
The improvement set forth in claim 1 in which said pad comprises four layers and in which said first and second outer layers are formed of a hard dielectric silicon resin, a third layer adjacent a first of said outer layers is formed of a silicon resin of predetermined tensile strength, and a fourth layer adjacent a second of said outer layers is formed of a silicon resin softer than said outer layers.
Claim 6
Dependent Claim
86 words
The improvement as set forth in claim 4 in which said first outer layer is formed of, approximately, a 0.3 mm thick equivalent of Dow Corning 527 silicon resin, said second outer layer is formed of, approximately, a 0.6 mm thick equivalent of Dow Corning 527 silicon resin, said third layer is formed of, approximately, a 0.3 mm thick equivalent of Dow Corning Sylgard 184 silicon resin, and said fourth layer is formed, of approximately, a 3.3 mm thick equivalent of Dow Corning 527 silicon resin.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-11-03 | 1990-05-05 | 1990-11-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-11-03 | 1994-05-05 | 1994-11-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-11-03 | 1998-05-05 | 1998-11-04 | $7700.00 | Window Closed / Lapsed |