US3633058A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Color picture tube with rectangular hall shadow mask
Assignee: NEC Corp
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Filing: 1970-01-21
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Granted: 1972-01-04
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Expires: 1990-01-21
Abstract
Abstract A cathode-ray tube for displaying colored images comprises an in-line three-element gun and a shadow mask. The shadow mask has formed therein a plurality of rectangular holes arranged in an orderly manner in rows and columns. The dimensions and spacing of the rectangular holes is selected to provide for optimum transmission of the electron beams to the screen, while still providing mechanical strength for the shadow mask.
Inventors
- 👤 Akiyoshi Kouno
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 10:07
CPC Classifications
H; H01; H01J; H01J29/00; H01J29/02; H01J29/06; H01J29/07; H01J29/076
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
179 words
A color cathode-ray tube comprising a shadow mask, an electron gun for producing three electron beams aligned on a straight line for convergence on said shadow mask, and a display screen comprising rectangular luminescent dots, said shadow mask having a pluraliTy of orderly arranged rectangular holes formed therein in a plurality of rows and columns, said holes being spaced by a distance a in each of said rows, and by a distance b in each of said columns, the ratio b/a being larger than 0.34 but smaller than 15, said rectangular holes in every other of said rows being offset with respect to the holes in an adjacent row so that all adjacent rectangular dots on said display screen luminesce differently in color when struck by the electron beam from said electron gun passing through said shadow mask rectangular holes; each of said rectangular holes having a wide side dimension of less than b and a narrow side dimension of less than a/3; said wide side being perpendicular to the direction on which said three electron beams are aligned.
Claim 2
Dependent Claim
179 words
A color cathode-ray tube comprising a shadow mask, an electron gun for producing three electron beams aligned on a straight line for convergence on said shadow mask, and a display screen comprising rectangular luminescent dots, said shadow mask having a pluraliTy of orderly arranged rectangular holes formed therein in a plurality of rows and columns, said holes being spaced by a distance a in each of said rows, and by a distance b in each of said columns, the ratio b/a being larger than 0.34 but smaller than 15, said rectangular holes in every other of said rows being offset with respect to the holes in an adjacent row so that all adjacent rectangular dots on said display screen luminesce differently in color when struck by the electron beam from said electron gun passing through said shadow mask rectangular holes; each of said rectangular holes having a wide side dimension of less than b and a narrow side dimension of less than a/3; said wide side being perpendicular to the direction on which said three electron beams are aligned.
Claim 3
Dependent Claim
37 words
The cathode-ray tube of claim 1, in which the rectangular holes in immediately adjacent ones of said columns are not aligned, and the rectangular holes in every other one of said rows are arranged in aligned columns.
Claim 4
Dependent Claim
24 words
The cathode-ray tube of claim 2, in which said luminescent dots are substantially the same size as said rectangular holes in said shadow mask.
Claim 5
Dependent Claim
40 words
The cathode-ray tube of claim 3, in which said luminescent dots are arranged in groups of three, the central one of each of said groups of dots being located closely to and in registration with one of said rectangular holes.
References Cited (Backward Citations)
CA598821A
Cited
DE1112542B
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-01-03 | 1975-07-05 | 1976-01-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-03 | 1979-07-05 | 1980-01-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-03 | 1983-07-05 | 1984-01-04 | $7700.00 | Window Closed / Lapsed |