Patent US4066332A successfully refreshed from Google Patents.
US4066332A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rear projection screens
Assignee: Fujifilm Holdings Corp
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Filing: 1976-01-23
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Granted: 1978-01-03
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Expires: 1996-01-23
Abstract
Abstract A rear projection screen having means for controlling light direction comprising a light diffusion plate composed of wax, a crystalline polymer or a mixture thereof, and light shielding layers contained in the light diffusion plate which are parallel to the direction of image projection.
Inventors
- 👤 Hisatoyo Kato
- 👤 Junji Miyahara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 13:22
CPC Classifications
G; G03; G03B; G03B21/00; G03B21/54; G03B21/56; G03B21/60; G03B21/62
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
47 words
A rear projection screen comprising a light diffusion plate formed of a material selected from the group consisting of wax, a crystalline polymer and mixtures thereof, and light shielding layers contained in said light-diffusion plate, said light shielding layers being parallel to the direction of image projection.
Claim 2
Dependent Claim
47 words
A rear projection screen comprising a light diffusion plate formed of a material selected from the group consisting of wax, a crystalline polymer and mixtures thereof, and light shielding layers contained in said light-diffusion plate, said light shielding layers being parallel to the direction of image projection.
Claim 3
Dependent Claim
23 words
The rear projection screen according to claim 1, wherein the wax is selected from the group consisting of natural wax and petroleum wax.
Claim 4
Dependent Claim
22 words
The rear projection screen according to claim 1, wherein the crystalline polymer has a molecular weight of not less than about 10,000.
Claim 5
Dependent Claim
30 words
The rear projection screen according to claim 3, wherein the crystalline polymer is selected from the group consisting of polyolefins, polystyrenes, polycarbonates, polyesters, polyamides, polyurethanes, polyvinyl alcohols, polyesters and polyethers.
Claim 6
Dependent Claim
24 words
The rear projection screen according to claim 1, wherein the thickness of any light shielding layer is about 50 to about 1 82 .
Claim 7
Dependent Claim
33 words
The rear projection screen according to claim 1, wherein the effective grid radio of the light shielding layer is about 0.3 to about 3, effective grid ratio being calculated by the formula: ##EQU3##
Claim 8
Dependent Claim
14 words
The rear projection screen according to claim 1, wherein the wax is synthetic wax.
Claim 9
Dependent Claim
35 words
The rear projection screen according to claim 1, wherein the molecular weight of synthetic wax is not more than about 5,000, and the melt index of the synthetic wax is not less than about 1,000.
Claim 10
Dependent Claim
23 words
The rear projection screen according to claim 1, wherein the thickness of the light diffusion plate ranges between about 0.1 to 4 mm.
Claim 11
Dependent Claim
19 words
The rear projection screen according to claim 2, wherein the light diffusion plate further contains a wax modifying agent.
Claim 12
Dependent Claim
19 words
The rear projection screen according to claim 7, wherein the light diffusion plate further contains a wax modifying agent.
Claim 13
Dependent Claim
60 words
A rear projection screen comprising a light diffusion plate formed of a material selected from the group consisting of wax, a crystalline polymer and mixtures thereof, and light shielding layers contained in said light-diffusion plate, said light shielding layers being parallel to the direction of image projection, the thickness of the light diffusion plate ranging between 0.1 to 4 mm.
Claim 14
Dependent Claim
60 words
A rear projection screen comprising a light diffusion plate formed of a material selected from the group consisting of wax, a crystalline polymer and mixtures thereof, and light shielding layers contained in said light-diffusion plate, said light shielding layers being parallel to the direction of image projection, the thickness of the light diffusion plate ranging between 0.1 to 4 mm.
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) | 1981-01-02 | 1981-07-04 | 1982-01-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-01-02 | 1985-07-04 | 1986-01-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-01-02 | 1989-07-04 | 1990-01-03 | $7700.00 | Window Closed / Lapsed |