US3732133A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Re-etch method
Assignee: Zenith Electronics LLC
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Filing: 1971-08-02
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Granted: 1973-05-08
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Expires: 1991-08-02
Abstract
Abstract A PROCESS FOR RE-ETCHING THE APERTURES OF A COLOR CAHODE-RAY TUBE SHADOW MASK TO INCREASE THE DIAMETER OF EACH APERTURE BY AN AMOUNT DEPENDENT UPON ITS SPACING FROM THE CENTER OF THE MASK BY FLOWING A FLUID ETCHANT THROUGH THE MASK APERTURES AND CONTROLLING THE VELOCITY OF ETCHANT FLOW THROUGH THE APERTURES TO DIFFER FROM APERTURE TO APERTURE AS A FUNCTION OF THE SPACING.
Inventors
- 👤 J Schwartz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 14:34
CPC Classifications
H; H01; H01J; H01J9/00; H01J9/02; H01J9/14; H01J9/142
Claims Analysis
Total Claims: 0
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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) | 1976-05-07 | 1976-11-06 | 1977-05-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-07 | 1980-11-06 | 1981-05-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-07 | 1984-11-06 | 1985-05-08 | $7700.00 | Window Closed / Lapsed |