US3707640A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Shadow mask having double-sized apertures
Assignee: Zenith Electronics LLC
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Filing: 1970-06-18
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Granted: 1972-12-26
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Expires: 1990-06-18
Abstract
Abstract The shadow mask of a color picture tube has a field of apertures each of which includes a small-diameter portion surrounded by a web usually having a thickness less than half the thickness of the sheet from which the mask is formed. The web thickness, instead of being uniform over the aperture field, decreases with radial distance from the center of the field.
Inventors
- 👤 Martin L Lerner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 03:45
CPC Classifications
H; H01; H01J; H01J29/00; H01J29/02; H01J29/06; H01J29/07; H01J29/076
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
107 words
A shadow mask structure for a color picture tube comprising: a sheet of material that may be chemically milled having a multiplicity of similar apertures disposed throughout a field of a particular configuration; each of said apertures having a small-diameter portion and further having a large-diameter portion in communication and in coaxial alignment with said small-diameter portion and defining therewith a web which surrounds the small-diameter portion of such aperture, each such web having a discrete thickness at its boundary with the small-diameter portion of its associated aperture, and the thickness of each web being inversely proportional to its radial distance from the center of said field.
Claim 2
Dependent Claim
107 words
A shadow mask structure for a color picture tube comprising: a sheet of material that may be chemically milled having a multiplicity of similar apertures disposed throughout a field of a particular configuration; each of said apertures having a small-diameter portion and further having a large-diameter portion in communication and in coaxial alignment with said small-diameter portion and defining therewith a web which surrounds the small-diameter portion of such aperture, each such web having a discrete thickness at its boundary with the small-diameter portion of its associated aperture, and the thickness of each web being inversely proportional to its radial distance from the center of said field.
Claim 3
Dependent Claim
24 words
A shadow mask structure in accordance with claim 1 in which the small-diameter portions of all of said apertures have approximately the same diameter.
Claim 4
Dependent Claim
35 words
A shadow mask structure in accordance with claim 1 in which the diameter of said large-diameter portion of said apertures increases with the radial distance of any such aperture from the center of said field.
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) | 1975-12-26 | 1976-06-26 | 1976-12-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-12-26 | 1980-06-26 | 1980-12-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-12-26 | 1984-06-26 | 1984-12-26 | $7700.00 | Window Closed / Lapsed |