US4767186A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Front projection screen with rear light concentrating lens array
Assignee: Philips North America LLC
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Filing: 1987-10-06
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Granted: 1988-08-30
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Expires: 2007-10-06
Abstract
Abstract LCD color television front projection screen has a rear vertically oriented lenticular lens array, the sidewalls of the lenticules steeply inclined to achieve total internal reflection of rays from a projected image into tip regions of the lenticules, an external reflective surface behind the array for reflecting the projected rays back into an audience field in front of the screen, and black masking between the lenticules for absorbing ambient rays.
Inventors
- 👤 Ralph H. Bradley, Jr.
- 👤 William F. Guerinot
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 16:11
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/12; H04N9/31; G; G03; G03B; G03B21/00; G03B21/54; G03B21/56; G03B21/60; G03B21/602
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
94 words
Front projection screen having: a light transmissive layer having a front surface and a rear surface defining a lenticular lens array comprising sequentially adjacent lens elements, each element having a tip portion and sidewall portions, the sidewall portions steeply inclined to direct light from a projection source by total internal reflection to the tip portions; external light reflective means adjacent to at least the tip portions for reflecting the directed light back through the screen and into an audience field; and light-absorbing means adjacent to at least the sidewall portions for absorbing ambient light.
Claim 2
Dependent Claim
94 words
Front projection screen having: a light transmissive layer having a front surface and a rear surface defining a lenticular lens array comprising sequentially adjacent lens elements, each element having a tip portion and sidewall portions, the sidewall portions steeply inclined to direct light from a projection source by total internal reflection to the tip portions; external light reflective means adjacent to at least the tip portions for reflecting the directed light back through the screen and into an audience field; and light-absorbing means adjacent to at least the sidewall portions for absorbing ambient light.
Claim 3
Dependent Claim
33 words
The screen of claim 1 in which the lenticular lens array comprises vertically oriented mutually parallel lenticular lens elements extending the entire vertical length of the screen, each lenticule having two sidewall portions.
Claim 4
Dependent Claim
17 words
The screen of claim 1 in which the sidewall portions of the lens elements are convexly curved.
Claim 5
Dependent Claim
25 words
The screen of claim 1 in which the external reflective means comprises a layer having a mirrored surface adjacent the rear surface of the array.
Claim 6
Dependent Claim
21 words
The screen of claim 4 in which the mirrored surface is optically coupled to the tip portions of the lens elements.
Claim 7
Dependent Claim
26 words
The screen of claim 4 in which the light absorbing means comprises black masking in the spaces between adjacent lens elements of the lenticular lens array.
Claim 8
Dependent Claim
13 words
The screen of claim 6 in which the black masking comprises black filaments.
Claim 9
Dependent Claim
13 words
The screen of claim 6 in which the black masking comprises black particles.
Claim 10
Dependent Claim
26 words
The screen of claim 1 in which the external reflective means comprises a coating having a mirrored surface on the tip portions of the lens elements.
Claim 11
Dependent Claim
26 words
The screen of claim 9 in which the light absorbing means comprises a layer having a light absorbing surface adjacent the rear surface of the array.
Claim 12
Dependent Claim
37 words
The screen of claim 2 in which the lenticular elements have a height to base width ratio of from about 2:1 to 20:1 and a base width to tip width ratio of from about 1:2 to 6:1.
Claim 13
Dependent Claim
14 words
The screen of claim 1 in which the front surface has an anti-reflective coating.
Claim 14
Dependent Claim
14 words
The screen of claim 1 in which the front surface has an anti-reflective texture.
Claim 15
Dependent Claim
11 words
The screen of claim 1 which additionally comprises optical diffusion means.
Claim 16
Dependent Claim
11 words
The screen of claim 1 which additionally comprises a Fresnel lens.
Claim 17
Dependent Claim
20 words
The screen of claim 15 in which the Fresnel lens is on the front surface of the light transmissive layer.
Claim 18
Dependent Claim
17 words
The screen of claim 15 in which the Fresnel lens is embedded in the light transmissive layer.
Claim 19
Dependent Claim
17 words
The screen of claim 15 in which the Fresnel lens is circular and the screen is flat.
Claim 20
Dependent Claim
27 words
The screen of claim 15 in which the Fresnel lens is linear and oriented in the horizontal direction, and the screen is curved in the horizontal direction.
Claim 21
Dependent Claim
16 words
The screen of claim 19 in which the facets are curved in the vertical cross section.
Claim 22
Dependent Claim
14 words
The screen of claim 1 which additionally comprises a horizontally oriented lenticular lens array.
Claim 23
Dependent Claim
16 words
The screen of claim 21 in which the array is embedded in the light transmissive layer.
Claim 24
Dependent Claim
36 words
The screen of claim 1 in which the lenticular lens array comprises vertically and horizontally adjacent lens elements, each element comprising a truncated pyramid having a rectangular base portion, four sidewall portions and a tip portion.
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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) | 1991-08-30 | 1992-02-29 | 1992-08-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-08-30 | 1996-02-29 | 1996-08-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-08-30 | 2000-02-29 | 2000-08-30 | $7700.00 | Window Closed / Lapsed |