US3784282A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Correcting lens used to form fluorescent screens of colour television receiving tubes
Assignee: Hitachi Ltd
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Filing: 1972-02-23
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Granted: 1974-01-08
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Expires: 1992-02-23
Abstract
Abstract In a correcting lens utilized to form the fluorescent screen of a colour television receiving tube, the lens being of the type wherein the effective surface of the lens through which the effective light beams pass is divided into a plurality of discontinuous effective regions of relatively small inclination angles with respect to the bottom surface of the lens and the adjacent effective regions are interconnected by connecting regions of larger inclination angles with respect to the bottom surface, opaque or translucent films are applied to the connecting regions.
Inventors
- 👤 E Yamazaki
- 👤 K Maruyama
- 👤 T Ueda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 13:10
CPC Classifications
G; G02; G02B; G02B3/00; G02B3/02; G02B3/08; H; H01; H01J; H01J9/00; H01J9/20; H01J9/22; H01J9/227; H01J9/2271; H01J9/2272; H01J9/2273
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
136 words
In a single correcting lens adapted to be used for refracting light for forming the entire area of a fluorescent screen of a colour television receiving tube, said lens being of the type wherein the effective refracting surface of the lens through which the useful exposure light beams pass is divided into a plurality of discontinuous effective elemental regions with two dimensional boundaries, said elemental regions having surfaces of relatively small inclination angles with respect to the bottom surface of the lens and the adjacent effective elemental regions interconnected at said boundaries by contiguous connecting ineffective refracting regions of larger surface inclination angles with respect to the bottom surface, the improvement which comprises light intercepting films applied only to said connecting ineffective regions of larger surface inclination for substantially reducing the intensity of erroneously refracted beams.
Claim 2
Dependent Claim
136 words
In a single correcting lens adapted to be used for refracting light for forming the entire area of a fluorescent screen of a colour television receiving tube, said lens being of the type wherein the effective refracting surface of the lens through which the useful exposure light beams pass is divided into a plurality of discontinuous effective elemental regions with two dimensional boundaries, said elemental regions having surfaces of relatively small inclination angles with respect to the bottom surface of the lens and the adjacent effective elemental regions interconnected at said boundaries by contiguous connecting ineffective refracting regions of larger surface inclination angles with respect to the bottom surface, the improvement which comprises light intercepting films applied only to said connecting ineffective regions of larger surface inclination for substantially reducing the intensity of erroneously refracted beams.
Claim 3
Dependent Claim
24 words
The correcting lens as claimed in claim 1 wherein said discontinuous effective regions are in the form of flat surfaces of different inclination angles.
Claim 4
Dependent Claim
25 words
The correcting lens as claimed in claim 1 wherein said discontinuous effective regions are in the form of curved surfaces of different radii of curvature.
Claim 5
Dependent Claim
18 words
The correcting lens as claimed in claim 1 wherein said light intercepting films are made of opaque substance.
Claim 6
Dependent Claim
18 words
The correcting lens as claimed in claim 1 wherein said light intercepting films are made of translucent substance.
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) | 1977-01-07 | 1977-07-09 | 1978-01-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-07 | 1981-07-09 | 1982-01-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-07 | 1985-07-09 | 1986-01-08 | $7700.00 | Window Closed / Lapsed |