US4143943A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rear projection screen system
Assignee: Xerox Corp
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Filing: 1977-02-17
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Granted: 1979-03-13
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Expires: 1997-02-17
Abstract
Abstract A rear projection screen which eliminates speckle by only linear diffuser surface motion. One of a pair of closely spaced plates of the rear projection screen is maintained fixed while the other plate is driven such that it has a linear motion relative to the fixed plate. The plates are optically transparent and have their facing surfaces etched or coated to provide adjacent diffusing surfaces. The driven screen is supported by L-shaped spring metal straps thereby providing a strong plate support assembly which can operate at low noise levels and with low drive-power requirements.
Inventors
- 👤 Eric G. Rawson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 04:37
CPC Classifications
G; G03; G03B; G03B21/00; G03B21/54; G03B21/56
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
76 words
A rear image projection system comprising: first and second closely spaced, optically transparent plates, each of said plates having a light diffusing surface; means for projecting an image upon said plates; means for maintaining said first screen in a stationary position; a plurality of flexible L-shaped spring straps for supporting said second screen; and drive means coupled to said second screen for providing said second screen with only a linear motion relative to said first screen.
Claim 2
Dependent Claim
76 words
A rear image projection system comprising: first and second closely spaced, optically transparent plates, each of said plates having a light diffusing surface; means for projecting an image upon said plates; means for maintaining said first screen in a stationary position; a plurality of flexible L-shaped spring straps for supporting said second screen; and drive means coupled to said second screen for providing said second screen with only a linear motion relative to said first screen.
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) | 1982-03-12 | 1982-09-11 | 1983-03-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-03-12 | 1986-09-11 | 1987-03-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-03-12 | 1990-09-11 | 1991-03-13 | $7700.00 | Window Closed / Lapsed |