Patent US4558922A successfully refreshed from Google Patents.
US4558922A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Bright viewing and focusing screens
Assignee: BEATTIE SYSTEMS Inc A CORP OF TN
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Filing: 1984-05-09
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Granted: 1985-12-17
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Expires: 2004-05-09
Abstract
Abstract An image forming screen for optical systems has a Fresnel plastic lens having a replica of a ground glass surface on the surface opposite to that of the rings. The image surface is coated with a thin layer of optically clear epoxy material increasing the brightness of images formed on the screen.
Inventors
- 👤 Harry L. O. Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 13:08
CPC Classifications
G; G03; G03B; G03B13/00; G03B13/18; G03B13/24
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
94 words
An image forming screen for optical systems comprising a substantially rectangular body formed from an optical grade of synthetic plastic material having spaced exterior surfaces, one of said surfaces comprising a series of concentric rings forming a Fresnel lens, and the other surface comprising the image surface, said image surface having a replica of a ground glass surface, said image surface being coated with a void filling thin layer of optically clear material having an index of refraction of about 1.55 to 1.65 and at least a 95 percent transmission of visible spectrum light.
Claim 2
Dependent Claim
94 words
An image forming screen for optical systems comprising a substantially rectangular body formed from an optical grade of synthetic plastic material having spaced exterior surfaces, one of said surfaces comprising a series of concentric rings forming a Fresnel lens, and the other surface comprising the image surface, said image surface having a replica of a ground glass surface, said image surface being coated with a void filling thin layer of optically clear material having an index of refraction of about 1.55 to 1.65 and at least a 95 percent transmission of visible spectrum light.
Claim 3
Dependent Claim
16 words
An image forming screen as recited in claim 1, wherein said coated material is an epoxy.
Claim 4
Dependent Claim
14 words
An image forming screen as recited in claim 1, wherein said surfaces are planar.
Claim 5
Dependent Claim
14 words
An image forming screen as recited in claim 1, wherein said material is acrylic.
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) | 1988-12-16 | 1989-06-17 | 1989-12-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-12-16 | 1993-06-17 | 1993-12-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-12-16 | 1997-06-17 | 1997-12-17 | $7700.00 | Window Closed / Lapsed |