US3922049A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of degassing a cathode-ray tube prior to sealing
Assignee: RCA Licensing Corp
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Filing: 1974-03-25
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Granted: 1975-11-25
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Expires: 1994-03-25
Abstract
Abstract A method for making a cathode-ray tube including baking the envelope and mount assembly and simultaneously exhausting gases from the envelope, and then sealing (tipping off) the exhausted envelope. During the baking and exhausting of the tube, the following steps are carried out first sequentially and then simultaneously: (a) applying radio-frequency energy to the mount assembly and (b) passing electric current through the cathode heater.
Inventors
- 👤 Frank Stanley Sawicki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 03:45
CPC Classifications
H; H01; H01J; H01J9/00; H01J9/38; H01J9/385
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
106 words
In a method for making a cathode-ray tube comprising an envelope and a mount assembly including at least one cathode and a heater therefor sealed in said envelope, said method including the steps of baking said envelope and mount assembly at about 300* to 450*C and simultaneously exhausting gases from said envelope and then sealing said envelope, the steps during said baking and exhausting of said envelope comprising first (1) sequentially and then (2) simultaneously (a) applying radio-frequency energy to said mount assembly and (b) passing electric current through said heater, whereby said simultaneous application step (2) heats said mount assembly including said cathode above 450*C.
Claim 2
Dependent Claim
106 words
In a method for making a cathode-ray tube comprising an envelope and a mount assembly including at least one cathode and a heater therefor sealed in said envelope, said method including the steps of baking said envelope and mount assembly at about 300* to 450*C and simultaneously exhausting gases from said envelope and then sealing said envelope, the steps during said baking and exhausting of said envelope comprising first (1) sequentially and then (2) simultaneously (a) applying radio-frequency energy to said mount assembly and (b) passing electric current through said heater, whereby said simultaneous application step (2) heats said mount assembly including said cathode above 450*C.
Claim 3
Dependent Claim
18 words
The method defined in claim 1 wherein said simultaneous step (2) is conducted for at least 2 minutes.
Claim 4
Dependent Claim
213 words
In a method for making a cathode-ray tube comprising an envelope having a neck portion, a mount assembly sealed in said neck portion, said mount assembly including at least one indirectly-heated thermionic cathode having an emitting side and a heated side, a grid spaced from said emitting side of said cathode and a heater spaced from the heated side of said cathode, and an exhaust tubulation extending from said envelope, said method including the steps of baking said envelope and mount assembly at about 300* to 450*C, simultaneously exhausting gases from inside said envelope through said exhaust tubulation and, in sequence during said baking and exhausting steps: a. applying radio-frequency energy to said mount assembly to heat the metal parts thereof above 450*C, b. reMoving said radio-frequency energy, c. passing electric current through the heater of said mount assembly to heat the cathode thereof above 450*C, d. then simultaneously passing electric current through said heater and applying radio-frequency energy to said mount assembly to heat both said cathode and the metal parts of said mount assembly above 450*C, e. removing said simultaneously applied electric current from said heater and radio-frequency energy from said mount assembly, and f. sealing off said exhaust tubulation envelope to seal the interior of said tube from the ambient.
Claim 5
Dependent Claim
213 words
In a method for making a cathode-ray tube comprising an envelope having a neck portion, a mount assembly sealed in said neck portion, said mount assembly including at least one indirectly-heated thermionic cathode having an emitting side and a heated side, a grid spaced from said emitting side of said cathode and a heater spaced from the heated side of said cathode, and an exhaust tubulation extending from said envelope, said method including the steps of baking said envelope and mount assembly at about 300* to 450*C, simultaneously exhausting gases from inside said envelope through said exhaust tubulation and, in sequence during said baking and exhausting steps: a. applying radio-frequency energy to said mount assembly to heat the metal parts thereof above 450*C, b. reMoving said radio-frequency energy, c. passing electric current through the heater of said mount assembly to heat the cathode thereof above 450*C, d. then simultaneously passing electric current through said heater and applying radio-frequency energy to said mount assembly to heat both said cathode and the metal parts of said mount assembly above 450*C, e. removing said simultaneously applied electric current from said heater and radio-frequency energy from said mount assembly, and f. sealing off said exhaust tubulation envelope to seal the interior of said tube from the ambient.
Claim 6
Dependent Claim
19 words
The method of claim 3 wherein said simultaneous application step (d) heats said grid and said cathode above 600*C.
References Cited (Backward Citations)
US2532315A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-24 | 1979-05-26 | 1979-11-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-24 | 1983-05-26 | 1983-11-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-24 | 1987-05-26 | 1987-11-25 | $7700.00 | Window Closed / Lapsed |