US3582189A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ambient light filter for a television receiver
Assignee: Zenith Electronics LLC
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Filing: 1968-08-19
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Granted: 1971-06-01
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Expires: 1988-08-19
Abstract
Abstract A light-masking device for improving the contrast of a television image under conditions of high ambient light comprises an optical filter having a grid of parallel alternately opaque and transparent strips of sufficient width to discriminate against nonplanar incident light. Mounting tabs selectively support the filter in a first position in front of the viewing screen such that the strips are inclined from the horizontal in one direction to discriminate against light directed from above and to the left and alternately in a second position such that the strips are inclined from the horizontal in the opposite direction to discriminate against light directed from above and to the right. The resulting structure is compact and economical to manufacture.
Inventors
- 👤 Scott No Moritz
- 👤 Eugene J Polley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 04:59
CPC Classifications
H; H01; H01J; H01J29/00; H01J29/86; H01J29/89; H01J29/896; H01J2229/00; H01J2229/89; H01J2229/8913; H01J2229/8922
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
191 words
A stationary light-masking device for the viewing screen of a television receiver for reducing the degrading effect of ambient light on the image produced thereon comprising: an optical filter comprising a detachably mountable sheet of transparent material in which a plurality of thin opaque strips are embedded edgewise to the plane of said viewing screen in substantially equispaced, oblique, and nonintersecting parallel rows, said strips having sufficient widths to discriminate against ambient light nonplanar to said strips while allowing light coplanar thereto to freely pass through said viewing screen; and mounting means for selectively supporting said filter in a first position in front of said screen in which said strips are inclined from the horizontal in one directiOn to selectively discriminate against light incident from above and to the left of said screen; and in a second position in which said strips are inclined from the horizontal in the opposite direction to selectively discriminate against light incident from above and to the right of said screen wherein one side of said filter faces said viewing screen in said first position and the other side faces said screen in said second position.
Claim 2
Dependent Claim
191 words
A stationary light-masking device for the viewing screen of a television receiver for reducing the degrading effect of ambient light on the image produced thereon comprising: an optical filter comprising a detachably mountable sheet of transparent material in which a plurality of thin opaque strips are embedded edgewise to the plane of said viewing screen in substantially equispaced, oblique, and nonintersecting parallel rows, said strips having sufficient widths to discriminate against ambient light nonplanar to said strips while allowing light coplanar thereto to freely pass through said viewing screen; and mounting means for selectively supporting said filter in a first position in front of said screen in which said strips are inclined from the horizontal in one directiOn to selectively discriminate against light incident from above and to the left of said screen; and in a second position in which said strips are inclined from the horizontal in the opposite direction to selectively discriminate against light incident from above and to the right of said screen wherein one side of said filter faces said viewing screen in said first position and the other side faces said screen in said second position.
Claim 3
Dependent Claim
27 words
A light-masking device as described in claim 1 wherein the inclination of said strips relative to the horizontal in said first and second positions is approximately 30*.
Claim 4
Dependent Claim
33 words
A light-masking device as described in claim 1 wherein said mounting means comprises a plurality of tabs arranged horizontally symmetrical and vertically asymmetrical to enable said filter to be reversed but not inverted.
Claim 5
Dependent Claim
70 words
A light-masking device as described in claim 1 wherein said sheet of transparent material is of a given thickness while said opaque strips embedded edgewise therein exhibit thicknesses on the order of one-tenth said sheet thickness and widths greater than one-half said sheet thickness, said opaque strips being aligned in said parallel rows at a spacing therebetween on the order of one-half that of the thickness of said transparent sheet.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-05-31 | 1974-11-30 | 1975-06-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-31 | 1978-11-30 | 1979-06-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-31 | 1982-11-30 | 1983-06-01 | $7700.00 | Window Closed / Lapsed |