US4490010A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rear projection screen
Assignee: Dai Nippon Printing Co Ltd
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Filing: 1983-06-09
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Granted: 1984-12-25
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Expires: 2003-06-09
Abstract
Abstract A rear projection screen has a rear side consisting of an array of convex lenses and a front side consisting of also convex lenses whose optic axes are substantially in line with those of the convex lenses at the rear side. Projections or raised portions are provided which surround the front convex lenses and are extended forwardly thereof and light masking strips or layers are formed over the projections or raised portions.
Inventors
- 👤 Makoto Honda
- 👤 Akira Izawa
- 👤 Yutaro Moriguchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 00:18
CPC Classifications
G; G03; G03B; G03B21/00; G03B21/54; G03B21/56; G03B21/60; G03B21/62; G03B21/625
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
128 words
A rear projection screen used as a screen of television systems or the like to form images thereon by rays of light projected from at least one projector located in a rear position of the screen, which comprises: a first lens surface formed on one side and having an array of a plurality of convex lenses; a second lens surface formed on the other side and having an array of a plurality of convex lenses whose axes are substantially in line with those of the convex lenses of said first lens surface; and light masking layers formed on projections or raised portions which are projected so as to surround each of convex lenses of the second lens surface and which are extended forwardly of said second lens surface.
Claim 2
Dependent Claim
128 words
A rear projection screen used as a screen of television systems or the like to form images thereon by rays of light projected from at least one projector located in a rear position of the screen, which comprises: a first lens surface formed on one side and having an array of a plurality of convex lenses; a second lens surface formed on the other side and having an array of a plurality of convex lenses whose axes are substantially in line with those of the convex lenses of said first lens surface; and light masking layers formed on projections or raised portions which are projected so as to surround each of convex lenses of the second lens surface and which are extended forwardly of said second lens surface.
Claim 3
Dependent Claim
40 words
A rear projection screen as set forth in claim 1, wherein each of the convex lenses of said second lens surface has its focal point located substantially on the surface of the corresponding convex lens of said first lens surface.
Claim 4
Dependent Claim
40 words
A rear projection screen as set forth in claim 2, wherein each of the convex lenses of said first lens surface has its focal point located substantially on the surface of the corresponding convex lens of said second lens surface.
Claim 5
Dependent Claim
61 words
A rear projection screen as set forth in claim 1, wherein the positions of said masking layers which are formed on said raised portions or projections are so displaced toward the edges of said screen that all the incident rays incident on the convex lenses of said first lens surface can pass the corresponding convex lenses of said second lens surface.
Claim 6
Dependent Claim
52 words
A rear projection screen as set forth in claim 1, wherein the top side edges of each of said raised portions or projections are beveled, and a light-masking or light-shielding material or ink is applied not only to the top of each raised portion or projection but also to the beveled portions.
Claim 7
Dependent Claim
32 words
A rear projection screen as set forth in claim 1, wherein the top of each of said raised portions or projections is projected in the shape of an arc in cross section.
References Cited (Backward Citations)
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Cited
US4172219A
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US4298246A
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US4431266A
Cited
US4443814A
Cited
US4432608A
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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) | 1987-12-25 | 1988-06-25 | 1988-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-12-25 | 1992-06-25 | 1992-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-12-25 | 1996-06-25 | 1996-12-25 | $7700.00 | Window Closed / Lapsed |