US3832032A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Lenticular rear projection screen
Assignee: Sony Corp
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Filing: 1973-04-20
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Granted: 1974-08-27
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Expires: 1993-04-20
Abstract
Abstract A rear projection screen in a projector which uses a cathode ray tube as an image light source has one side of the screen formed with a multiplicity of parallel lenticular ridges, while the other side of the screen has a plane surface provided with a plurality of light diffusing stripe-like areas arranged alternately thereacross. The lenticular ridges and the light diffusing stripe-like areas cooperate to provide light emerging from the screen with a horizontal diffusing angle that is controllably greater than the vertical diffusing angle thereof, and the light absorbing stripes are operative to absorb ambient light and thereby avoid deterioration of the contrast of an image projected through the screen onto the plane surface thereof.
Inventors
- 👤 S Shimada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 17:56
CPC Classifications
G; G03; G03B; G03B21/00; G03B21/54; G03B21/56; G03B21/60; G03B21/62; G03B21/625
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
129 words
A rear projection screen comprising a transparent sheet having a plane surface at one side of the sheet and its opposite surface constituted by a multiplicity of parallel lenticular ridges, said plane surface having a multiplicity of spaced-apart parallel light diffusing stripe-shaped areas each corresponding to a respective one of said lenticular ridges and extending parallel to the latter, said plane surface further having parallel light absorbing stripe-shaped areas interposed between said light diffusing stripe-shaped areas, said stripe-like areas extending vertically, and each of said light diffusing stripelike areas being constituted by numerous micro-grooves which are arranged so that light escaping from said sheet at said light diffusing stripe-like areas of the plane surface has a larger light diffusion angle in the horizontal direction than in the vertical direction.
Claim 2
Dependent Claim
129 words
A rear projection screen comprising a transparent sheet having a plane surface at one side of the sheet and its opposite surface constituted by a multiplicity of parallel lenticular ridges, said plane surface having a multiplicity of spaced-apart parallel light diffusing stripe-shaped areas each corresponding to a respective one of said lenticular ridges and extending parallel to the latter, said plane surface further having parallel light absorbing stripe-shaped areas interposed between said light diffusing stripe-shaped areas, said stripe-like areas extending vertically, and each of said light diffusing stripelike areas being constituted by numerous micro-grooves which are arranged so that light escaping from said sheet at said light diffusing stripe-like areas of the plane surface has a larger light diffusion angle in the horizontal direction than in the vertical direction.
Claim 3
Dependent Claim
32 words
A rear projection screen according to claim 1, in which said micro-grooves extend generally parallel to each other in directions substantially at right angles to the longitudinal directions of said stripe-like areas.
Claim 4
Dependent Claim
22 words
A rear projection screen according to claim 1, in which said micro-grooves are in a random arrangement in the respective stripe-like area.
Claim 5
Dependent Claim
20 words
A rear projection screen according to claim 3, in which each of said lenticular ridges constitutes a cylindrical lens element.
Claim 6
Dependent Claim
138 words
A rear screen projector comprising, an image light source, a transparent sheet having a plane front surface and a rear surface constituted by a multiplicity of vertically extending, parallel lenticular ridges, optical projection means for focusing the image from said light source through said sheet onto said plane front surface, said plane front surface of the transparent sheet having a multiplicity of spaced-apart parallel light diffusing stripe-shaped areas each corresponding to a respective one of said lenticular ridges and extending parallel to the latter, and said plane front surface further having parallel light absorbing stripe-shaped areas interposed between said light diffusing stripe-shaped areas, each of said light diffusIng stripe-like areas having a larger light diffusing angle in the horizontal direction than in the vertical direction as to light emerging from said sheet at said plane front surface thereof.
Claim 7
Dependent Claim
138 words
A rear screen projector comprising, an image light source, a transparent sheet having a plane front surface and a rear surface constituted by a multiplicity of vertically extending, parallel lenticular ridges, optical projection means for focusing the image from said light source through said sheet onto said plane front surface, said plane front surface of the transparent sheet having a multiplicity of spaced-apart parallel light diffusing stripe-shaped areas each corresponding to a respective one of said lenticular ridges and extending parallel to the latter, and said plane front surface further having parallel light absorbing stripe-shaped areas interposed between said light diffusing stripe-shaped areas, each of said light diffusIng stripe-like areas having a larger light diffusing angle in the horizontal direction than in the vertical direction as to light emerging from said sheet at said plane front surface thereof.
Claim 8
Dependent Claim
31 words
A rear screen projector according to claim 5, in which each of said light diffusing stripe-like areas has numerous micro-grooves exending horizontally in a random arrangement with respect to each other.
Claim 9
Dependent Claim
20 words
A rear screen projector according to claim 6, in which each of said lenticular ridges constitutes a cylindrical lens element.
Claim 10
Dependent Claim
100 words
A rear screen projector according to claim 5, in which said optical projection means includes a correcting Fresnel lens disposed in back of said transparent sheet and being operative to deflect horizontally toward a central axis the light rays that pass through the Fresnel lens from said image light source, and said light diffusing stripe-like areas which are spaced from said central axis are displaced laterally inward toward said axis from the longitudinal medians of the respective lenticular ridges by distances which progressively increase in accordance with the distance of the respective light diffusing stripe-like area from said central axis.
Claim 11
Dependent Claim
100 words
A rear screen projector according to claim 8, in which said Fresnel lens includes parallel arranged lens elements substantially aligned with said lenticular ridges, said optical projection means further includes a main focusing lens interposed between said image light source and said Fresnel lens, and the pitch PF of said lens elements of the Fresnel lens conforms to the following inequality: PF<D/L. phi L in which D is the distance from said Fresnel lens to said sheet, L is the distance from said main focusing lens to said sheet, and phi L is the diameter of said main focusing lens.
References Cited (Backward Citations)
US2618198A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-08-26 | 1978-02-25 | 1978-08-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-26 | 1982-02-25 | 1982-08-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-26 | 1986-02-25 | 1986-08-27 | $7700.00 | Window Closed / Lapsed |