Patent US6147801A successfully refreshed from Google Patents.
US6147801A
Expired / Lapsed
US
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Rear projection screen with reduced speckle
Assignee: Philips North America LLC
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Filing: 1997-08-18
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Granted: 2000-11-14
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Expires: 2017-08-18
Abstract
Abstract A rear projection screen which includes a front lenticular surface, a diffusion region behind the lenticular surface, a non-diffusion region behind the diffusion region, and a rear phase grating surface, when used with high magnification projection systems, exhibits reduced speckle when compared to other rear projection screen without such a grating.
Inventors
- 👤 Jill F. Goldenberg
- 👤 Qiang Huang
- 👤 Johannes C. van de Ven
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 08:17
CPC Classifications
G; G03; G03B; G03B21/00; G03B21/54; G03B21/56; G03B21/60; G03B21/62; G03B21/625; G03B33/00; G03B33/10; G03B33/14
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
66 words
A rear projection screen comprising: a front surface, defined by an array of mutually parallel lenticules for spreading light horizontally into an audience space, first diffusion means for diffusing light into the audience space, second diffusion means located behind the first diffusion means, and a non-diffusing region between the first and second diffusion means, wherein the thickness of the non-diffusing region is 1 to 5 mm.
Claim 2
Dependent Claim
66 words
A rear projection screen comprising: a front surface, defined by an array of mutually parallel lenticules for spreading light horizontally into an audience space, first diffusion means for diffusing light into the audience space, second diffusion means located behind the first diffusion means, and a non-diffusing region between the first and second diffusion means, wherein the thickness of the non-diffusing region is 1 to 5 mm.
Claim 3
Dependent Claim
19 words
The rear projection screen of claim 1 in which the second diffusion means consists of a bulk diffusion region.
Claim 4
Dependent Claim
17 words
The rear projection screen of claim 1 in which second diffusion means consists of a holographic diffuser.
Claim 5
Dependent Claim
21 words
The rear projection screen of claim 1 in which the first diffusion means comprises a roughening of the front lenticular surface.
Claim 6
Dependent Claim
19 words
The rear projection screen of claim 1 in which a fresnel lens is located behind the second diffusion means.
Claim 7
Dependent Claim
17 words
A rear projection screen as in claim 1 wherein said second diffusion means is a bulk diffuser.
Claim 8
Dependent Claim
17 words
A rear projection screen as in claim 6 wherein said first diffusion means is a bulk diffuser.
Claim 9
Dependent Claim
19 words
A rear projection screen as in claim 7 wherein said first and second diffusion means have the same thickness.
Claim 10
Dependent Claim
21 words
A rear projection screen as in claim 7 wherein said first and second diffusion means have a thickness below 1 mm.
Claim 11
Dependent Claim
24 words
A rear projection screen as in claim 1 wherein said second diffusion means diffuses light through the non-diffusing region toward the first diffusion means.
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) | 2003-11-14 | 2004-05-15 | 2004-11-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-11-14 | 2008-05-15 | 2008-11-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-11-14 | 2012-05-15 | 2012-11-14 | $7700.00 | Window Closed / Lapsed |