Patent US3814981A successfully refreshed from Google Patents.
US3814981A
Expired / Lapsed
US
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Horizontal centering circuit
Assignee: Thomas International Corp
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Filing: 1973-01-29
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Granted: 1974-06-04
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Expires: 1993-01-29
Abstract
Abstract A horizontal centering circuit having a variable differential coil with its center tap coupled to the junction between a horizontal deflection winding and an S-shaping capacitor and its outer ends coupled to a B+ voltage supply through oppositely poled diodes and which conducts a selected amount of current from the B+ voltage supply to or from the capacitor when the voltage thereacross is different from the B+ supply voltage. The horizontal centering current provides a selected DC offset current through a deflection coil for centering an electron beam on the screen of a cathode ray tube.
Inventors
- 👤 G Rusk
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 09:08
CPC Classifications
H; H04; H04N; H04N3/00; H04N3/10; H04N3/16; H04N3/22; H04N3/227
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
99 words
In a deflection circuit for a cathode ray tube having a source of reference potential and a deflection coil with one side thereof receiving a deflection signal and another side thereof being serially coupled with a capacitor, a centering circuit for providing a DC offset to the deflection coil, comprising: reactive impedance means coupled through conduction means between said source of reference potential and said other side of the deflection coil for providing a DC offset current through said deflection coil; and means for varying the reactive impedance of said reactive impedance means to alter said DC offset current.
Claim 2
Dependent Claim
99 words
In a deflection circuit for a cathode ray tube having a source of reference potential and a deflection coil with one side thereof receiving a deflection signal and another side thereof being serially coupled with a capacitor, a centering circuit for providing a DC offset to the deflection coil, comprising: reactive impedance means coupled through conduction means between said source of reference potential and said other side of the deflection coil for providing a DC offset current through said deflection coil; and means for varying the reactive impedance of said reactive impedance means to alter said DC offset current.
Claim 3
Dependent Claim
15 words
The centering current of claim 1 in which said reactive impedance means comprises inductor means.
Claim 4
Dependent Claim
24 words
The centering current of claim 1 in which said reactive impedance means conducts offset current between said source of reference potential and said capacitor.
Claim 5
Dependent Claim
76 words
The centering current of claim 3 in which said deflection signal produces across said capacitor, a periodic voltage signal having first and second portions, and said conduction means includes means for conducting current of one polarity through said reactive impedance means during one of the first and second portions of the periodic voltage signal and for conducting current at a second polarity opposite to said first polarity during the other of said first and second portions.
Claim 6
Dependent Claim
49 words
The centering current of claim 4 in which said impedance varying means includes means for varying the impedance of said reactive impedance means to selectively conduct a current of greater magnitude during one of said first and second portions than during the other of said first and second portions.
Claim 7
Dependent Claim
130 words
The centering circuit of claim 4 in which said conduction means includes a pair of reactive impedance elements comprising said reactive impedance means and both coupled at one end to said another side of said deflection coil, a first rectifying means coupled between the remaining end of one of said pair of rectifying means and said source of reference potential to conduct current therebetween during one of said first and second portions of the periodic voltage signal, and a second rectifying means poled oppositely with respect to said first rectifying means coupled between the remaining end oF the other one of said pair of reactive impedance elements and said source of reference potential to conduct current therebetween during the other of said first and second portions of the periodic signal.
Claim 8
Dependent Claim
30 words
The centering circuit of claim 6 in which said impedance varying means includes means for varying by different amounts the impedances of each of said pair of reactive impedance elements.
Claim 9
Dependent Claim
35 words
The centering unit of claim 7 in which the variation of impedance of one of the reactive impedance elements is indirectly related to the variation of impedance of the other of the reactive impedance elements.
Claim 10
Dependent Claim
40 words
The centering circuit of claim 8 in which said reactive impedance elements comprise inductance coils wound about a common bobbin and said impedance varying means comprises a single manually movable core for simultaneously varying the inductance of both inductance coils.
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) | 1977-06-03 | 1977-12-03 | 1978-06-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-03 | 1981-12-03 | 1982-06-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-03 | 1985-12-03 | 1986-06-04 | $7700.00 | Window Closed / Lapsed |