US5751478A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rear-projection screen
Assignee: Kuraray Co Ltd
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Filing: 1996-04-03
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Granted: 1998-05-12
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Expires: 2016-04-03
Abstract
Abstract A rear-projection screen having at least a Fresnel lens and a light-diffusing member, and is characterized by having vertical-direction light diffusion properties greater at its upper and lower end portions than at its middle portion. For example, the light-diffusing member contains light-diffusing fine particles and has a vertical lenticular lens that diffuses light in the vertical direction, provided on the light-incident surface of the Fresnel lens. This decreases the rainbows caused by misdirected light and also improves the brightness at the border, without causing a lowering of peak gain.
Inventors
- 👤 Osamu Yoshimura
- 👤 Ichiro Matsuzaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 19:16
CPC Classifications
G; G03; G03B; G03B21/00; G03B21/54; G03B21/56; G03B21/60; G03B21/62; G03B21/625
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
87 words
A rear projection screen, said screen comprising: a Fresnel lens structure, a first side of which is a first light-diffusing member, and a second side of which is a circular Fresnel lens surface, and a second light-diffusing member wherein said second light-diffusing member is spaced apart from the circular Fresnel lens structure and is adjacent to the Fresnel lens surface of said Fresnel lens structure, wherein said first light-diffusing member has vertical-light diffusion properties greater at its upper and lower end portions than at its middle portion.
Claim 2
Dependent Claim
87 words
A rear projection screen, said screen comprising: a Fresnel lens structure, a first side of which is a first light-diffusing member, and a second side of which is a circular Fresnel lens surface, and a second light-diffusing member wherein said second light-diffusing member is spaced apart from the circular Fresnel lens structure and is adjacent to the Fresnel lens surface of said Fresnel lens structure, wherein said first light-diffusing member has vertical-light diffusion properties greater at its upper and lower end portions than at its middle portion.
Claim 3
Dependent Claim
65 words
The rear-projection screen according to claim 1, wherein the middle portion of said screen has an extent which is within 15% in the height direction from the mechanical center of the Fresnel lens of the rear-projection screen, and the upper and lower end portions each have an extent which is 70% outward in the height direction from the mechanical center of the Fresnel lens thereof.
Claim 4
Dependent Claim
60 words
The rear-projection screen according to claim 1 or 2, wherein light-diffusing fine particles as a means for diffusing light in the vertical direction are incorporated in said first light-diffusing member, and the concentration of the light-diffusing fine particles in said first light-diffusing member is higher at the upper and lower end portions than at the middle portion of the screen.
Claim 5
Dependent Claim
47 words
The rear-projection screen according to claim 1, wherein said first light-diffusing member is a vertical lenticular lens that diffuses light in the vertical direction, and said vertical lenticular lens has vertical-direction light diffusion properties greater at its upper and lower end portions than at its middle portion.
Claim 6
Dependent Claim
44 words
The rear-projection screen according to claim 4, wherein said vertical lenticular lens has a constant height of lens hills, and has a pitch of lens hills which is smaller at the upper and lower end portions than at the middle portion of the screen.
Claim 7
Dependent Claim
44 words
The rear-projection screen according to claim 4, wherein said vertical lenticular lens has a constant pitch of lens hills, and has a height of lens hills which is greater at the upper and lower end portions than at the middle portion of the screen.
Claim 8
Dependent Claim
61 words
The rear-projection screen according to claim 4, wherein said vertical lenticular lens has a pitch of lens hills which is smaller at the upper and lower end portions than at the middle portion of the screen, and has a height of lens hills which is greater at the upper and lower end portions than at the middle portion of the screen.
References Cited (Backward Citations)
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GB2235990A
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US5457572A
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US5432636A
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US5477380A
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JPH07134338A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-05-11 | 2001-11-10 | 2002-05-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-05-11 | 2005-11-10 | 2006-05-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-05-11 | 2009-11-10 | 2010-05-12 | $7700.00 | Window Closed / Lapsed |