US3794873A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Interchangeable shadow mask
Assignee: Zenith Electronics LLC
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Filing: 1972-11-06
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Granted: 1974-02-26
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Expires: 1992-11-06
Abstract
Abstract A color television picture tube including an interchangeable multilayer shadow mask having a thin aperture-defining layer of a first material and a thick supporting layer of a second material. The mask is preformed while imperforate into its final curved configuration and the aperture pattern formed by photo-exposure and selective etching. The holes in the supporting layer are larger than the corresponding apertures in the aperture-defining layer to establish an increasing undercut graded in accordance with distance from the geometric center of the tube.
Inventors
- 👤 S Kaplan
- 👤 R Stachniak
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 16:02
CPC Classifications
H; H01; H01J; H01J29/00; H01J29/02; H01J29/06; H01J29/07; H01J9/00; H01J9/02; H01J9/14; H01J9/142
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
100 words
A two-layered interchangeable shadow mask for use in a color television picture tube having an electron beam scanned phosphor screen bearing faceplate panel of given contour, said mask generally conforming to the contour of the panel and comprising a thin layer of material defining a pattern of apertures supported by a thick base layer of a different material; said base layer defining a like plurality of holes corresponding to the apertures in said pattern, which holes increasingly undercut said apertures by an amount which is substantially proportional to the cotangent of the angle of electron beam incidence upon the mask.
Claim 2
Dependent Claim
100 words
A two-layered interchangeable shadow mask for use in a color television picture tube having an electron beam scanned phosphor screen bearing faceplate panel of given contour, said mask generally conforming to the contour of the panel and comprising a thin layer of material defining a pattern of apertures supported by a thick base layer of a different material; said base layer defining a like plurality of holes corresponding to the apertures in said pattern, which holes increasingly undercut said apertures by an amount which is substantially proportional to the cotangent of the angle of electron beam incidence upon the mask.
Claim 3
Dependent Claim
178 words
A color television picture tube including a contoured faceplate; a funnel having a large end mated to said faceplate and a neck housing an electron gun structure for directing electron beams toward said faceplate; a phosphor screen on the inner surface of said faceplate; and an interchangeable shadow mask positioned adjacent to and in registry with said phosphor screen, said shadow mask having a contour matching that of said inner surface of said face-plate and including a pattern of apertures for shadowing portions of said phosphor screen from all but selected electron beams from said gun structure; said shadow mask being constructed of a thin layer of a first material defining the apertures in said pattern and a thick layer of a second material providing support for said thin layer; said thick layer having a pattern of holes corresponding to said pattern of apertures with each hole being juxtaposed to a corresponding aperture and undercutting the same, the amount of said undercutting being substantially proportional to the cotangent of the angle of electron beam incidence upon the mask.
Claim 4
Dependent Claim
178 words
A color television picture tube including a contoured faceplate; a funnel having a large end mated to said faceplate and a neck housing an electron gun structure for directing electron beams toward said faceplate; a phosphor screen on the inner surface of said faceplate; and an interchangeable shadow mask positioned adjacent to and in registry with said phosphor screen, said shadow mask having a contour matching that of said inner surface of said face-plate and including a pattern of apertures for shadowing portions of said phosphor screen from all but selected electron beams from said gun structure; said shadow mask being constructed of a thin layer of a first material defining the apertures in said pattern and a thick layer of a second material providing support for said thin layer; said thick layer having a pattern of holes corresponding to said pattern of apertures with each hole being juxtaposed to a corresponding aperture and undercutting the same, the amount of said undercutting being substantially proportional to the cotangent of the angle of electron beam incidence upon the mask.
References Cited (Backward Citations)
US2663821A
Cited
US3519869A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-02-25 | 1977-08-27 | 1978-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-25 | 1981-08-27 | 1982-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-25 | 1985-08-27 | 1986-02-26 | $7700.00 | Window Closed / Lapsed |