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Patent US3966287A successfully refreshed from Google Patents.
US3966287A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low-voltage aging of cathode-ray tubes
Assignee: RCA Licensing Corp
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Filing: 1975-06-27
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Granted: 1976-06-29
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Expires: 1995-06-27
Abstract
Abstract During the low-voltage aging of a completely-assembled and operative cathode-ray tube, a varying positive voltage is applied to the focus electrode and a constant positive voltage is applied to the screen electrode while the cathode is emitting electrons. The effect is to cause electrons from the cathode to scan or spray across the electrode surfaces causing outgassing by electron bombardment of the scanned surfaces. This results in higher and more stable cathode-emission levels.
Inventors
- 👤 Paul Richard Liller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 04:55
CPC Classifications
H; H01; H01J; H01J9/00; H01J9/44; H01J9/445; H01J9/42
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
71 words
In a method of processing a completed cathode-ray tube having an electron gun including a cathode, a control electrode, a screen electrode, a focus electrode and a high-voltage electrode, the method including the steps of spot-knocking, hot-shot, high-voltage aging and low-voltage aging, the improvement comprising applying a varying positive voltage to said focus electrode and a constant positive voltage to said screen electrode during the low-voltage aging step of said processing.
Claim 2
Dependent Claim
71 words
In a method of processing a completed cathode-ray tube having an electron gun including a cathode, a control electrode, a screen electrode, a focus electrode and a high-voltage electrode, the method including the steps of spot-knocking, hot-shot, high-voltage aging and low-voltage aging, the improvement comprising applying a varying positive voltage to said focus electrode and a constant positive voltage to said screen electrode during the low-voltage aging step of said processing.
Claim 3
Dependent Claim
17 words
The method defined in claim 1 wherein said varying positive voltage is a half-wave rectified AC voltage.
Claim 4
Dependent Claim
31 words
The method defined in claim 1 wherein said varying positive voltage is a half-wave rectified 60 cycles AC voltage having peak voltages of at least 10% of said constant positive voltage.
Claim 5
Dependent Claim
113 words
In a method for processing a completed cathode-ray tube having an electron gun comprising a cathode, a control electrode, a screen electrode, a focus electrode and a high-voltage electrode, the method including the steps of spot-knocking, hot-shot, high-voltage aging and low-voltage aging, during the low-voltage aging step, the step of applying ground voltage to said cathode and said control electrode, a constant positive voltage of about 300 to 400 volts to said screen electrode, a varying positive voltage to said focus electrode, said varying voltage having voltage peaks of at least 10% of said constant positive voltage, said cathode being operative to emit electrons and said high-voltage electrode being permitted to float electrically.
Claim 6
Dependent Claim
113 words
In a method for processing a completed cathode-ray tube having an electron gun comprising a cathode, a control electrode, a screen electrode, a focus electrode and a high-voltage electrode, the method including the steps of spot-knocking, hot-shot, high-voltage aging and low-voltage aging, during the low-voltage aging step, the step of applying ground voltage to said cathode and said control electrode, a constant positive voltage of about 300 to 400 volts to said screen electrode, a varying positive voltage to said focus electrode, said varying voltage having voltage peaks of at least 10% of said constant positive voltage, said cathode being operative to emit electrons and said high-voltage electrode being permitted to float electrically.
Claim 7
Dependent Claim
26 words
The method defined in claim 4 wherein said varying positive voltage has peaks of about 300 to 400 volts and has minimums at about ground potential.
Claim 8
Dependent Claim
16 words
The method defined in claim 4 wherein said step is applied for 10 to 100 minutes.
Claim 9
Dependent Claim
17 words
The method defined in claim 5 wherein said step is applied for about 25 to 40 minutes.
Claim 10
Dependent Claim
19 words
The method defined in claim 5 wherein said varying positive voltage is a half wave rectified alternating current voltage.
Claim 11
Dependent Claim
44 words
The method defined in claim 5 wherein said varying positive voltage is applied for at least 25 percent of the time period that said step is applied, and a constant positive voltage or ground potential is applied for the balance of said time period.
Claim 12
Dependent Claim
26 words
The method defined in claim 5 wherein said varying positive voltage is applied for substantially 100 percent of the time period that said step is applied.
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) | 1979-06-29 | 1979-12-29 | 1980-06-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-06-29 | 1983-12-29 | 1984-06-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-06-29 | 1987-12-29 | 1988-06-29 | $7700.00 | Window Closed / Lapsed |