US3688360A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of manufacturing color picture tubes
Assignee: Hitachi Ltd
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Filing: 1970-10-28
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Granted: 1972-09-05
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Expires: 1990-10-28
Abstract
Abstract A method of manufacturing color picture tubes comprising the steps of forming openings or beam-permeating apertures in a color selective electrode with smaller dimensions than the ones finally required in the completed tube, exposing a phosphor screen on the inner surface of a face plate of a panel portion to light through said color selective electrode, thereafter coating an antietching protective film with the necessary portions uncovered by the inversion development process, and expanding said openings to said predetermined dimensions by etching.
Inventors
- 👤 Yoshihiko Miyata
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 09:43
CPC Classifications
H; H01; H01J; H01J9/00; H01J9/02; H01J9/14; H01J9/142
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
147 words
In a method of manufacturing a color picture tube which comprises a glass bulb including a panel portion, a funnel portion and a neck portion, a phosphor screen provided on the inner surface of a face plate of said panel portion, and a color selective electrode provided immediately in front of said phosphor screen within said glass bulb, the improvement comprising the steps of coating a substrate with a light responsive phosphor to form a phosphor screen, forming openings in a metal plate to be used as said color selective electrode with smaller dimensions than the openings finally required in the completed tube, exposing said phosphor screen to light solely through the openings in said color selective electrode, developing said phosphor screen and expanding the size of said openings in said plate to form said color selective electrode having proper dimensions for use in the completed tube.
Claim 2
Dependent Claim
147 words
In a method of manufacturing a color picture tube which comprises a glass bulb including a panel portion, a funnel portion and a neck portion, a phosphor screen provided on the inner surface of a face plate of said panel portion, and a color selective electrode provided immediately in front of said phosphor screen within said glass bulb, the improvement comprising the steps of coating a substrate with a light responsive phosphor to form a phosphor screen, forming openings in a metal plate to be used as said color selective electrode with smaller dimensions than the openings finally required in the completed tube, exposing said phosphor screen to light solely through the openings in said color selective electrode, developing said phosphor screen and expanding the size of said openings in said plate to form said color selective electrode having proper dimensions for use in the completed tube.
Claim 3
Dependent Claim
58 words
A method of manufacturing the color picture tube according to claim 1 wherein the step of expanding said openings to said predetermined dimensions comprises the steps of forming an anti-etching protective film on said color selective electrode with at least those portions desired for the expansion to said predetermined dimensions uncovered, and etching said uncovered portion for removal.
Claim 4
Dependent Claim
53 words
A method of manufacturing the color picture tube according to claim 2 wherein the step of forming said anti-etching protective film with said uncovered portions comprises the steps of coating said anti-etching protective film over the entire surface of said color selective electrode, and subjecting said shadow mask to the inversion development twice.
Claim 5
Dependent Claim
51 words
A method of manufacturing the color picture tube according claim 2 wherein the step of forming said anti-etching protective film with said uncovered portions comprises the steps of coating said anti-etching protective film over the entire surface of said color selective electrode, and subjecting said shadow mask to inversion development once.
References Cited (Backward Citations)
US3631576A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-09-05 | 1976-03-06 | 1976-09-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-05 | 1980-03-06 | 1980-09-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-05 | 1984-03-06 | 1984-09-05 | $7700.00 | Window Closed / Lapsed |