US4272777A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Service switch apparatus
Assignee: RCA Licensing Corp
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Filing: 1980-02-08
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Granted: 1981-06-09
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Expires: 2000-02-08
Abstract
Abstract In a television receiver having a vertical oscillator for providing a source of vertical deflection signals to a vertical deflection circuit, a service switch having normal and service positions is coupled to the vertical oscillator through an interference isolating diode. In the normal position, the diode is reverse biased, allowing the oscillator to function normally while eliminating the introduction of signal interference into the oscillator. While in the service position, the switch causes the diode to become forward biased, thereby disabling the oscillator and collapsing the vertical scan.
Inventors
- 👤 William V. Fitzgerald
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 04:22
CPC Classifications
H; H04; H04N; H04N3/00; H04N3/10; H04N3/16; H04N17/00; H04N17/04
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
156 words
In a television receiver including a vertical oscillator for providing a signal to a vertical deflection circuit, service switch apparatus comprising: a service switch, incorporating an electrical contact, said switch being adjustable between a first and a second position, said first position defining a condition in which a first potential is applied to said contact, said second position defining a condition in which a second potential, different than said first potential, is applied to said contact; a diode; means for coupling said diode between a point in said oscillator and said contact with such polarity that application of said first potential to said contact effects a forward biasing of said diode to cause conduction by said diode, said conduction effecting a disabling of said oscillator, whereas application of said second potential to said contact effects a reverse biasing of said diode, permitting normal operation of said vertical oscillator and decoupling said oscillator point from said contact.
Claim 2
Dependent Claim
156 words
In a television receiver including a vertical oscillator for providing a signal to a vertical deflection circuit, service switch apparatus comprising: a service switch, incorporating an electrical contact, said switch being adjustable between a first and a second position, said first position defining a condition in which a first potential is applied to said contact, said second position defining a condition in which a second potential, different than said first potential, is applied to said contact; a diode; means for coupling said diode between a point in said oscillator and said contact with such polarity that application of said first potential to said contact effects a forward biasing of said diode to cause conduction by said diode, said conduction effecting a disabling of said oscillator, whereas application of said second potential to said contact effects a reverse biasing of said diode, permitting normal operation of said vertical oscillator and decoupling said oscillator point from said contact.
Claim 3
Dependent Claim
53 words
Apparatus in accordance with claim 1: wherein said vertical oscillator comprises a transistor having an input electrode; said transistor, during normal operation of said oscillator, being periodically rendered nonconductive, wherein said point in said oscillator comprises said input electrode of said transistor; and wherein conduction by said diode maintains said transistor continuously conducting.
Claim 4
Dependent Claim
71 words
Apparatus in accordance with claim 2 wherein said transistor has base and emitter electrodes, said input electrode being one of said base and emitter electrodes; said apparatus also including: means for applying to the other of said base and emitter electrodes a third potential differing from said first potential such that adjustment of said switch to said first position forward biases the base-emitter path of said transistor via said conducting diode.
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) | 1984-06-08 | 1984-12-08 | 1985-06-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-06-08 | 1988-12-08 | 1989-06-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-06-08 | 1992-12-08 | 1993-06-09 | $7700.00 | Window Closed / Lapsed |