US3842311A
Expired / Lapsed
US
⏱️ 0.0 years remaining
S-corrected vertical deflection circuit
Assignee: RCA Licensing Corp
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Filing: 1973-01-08
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Granted: 1974-10-15
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Expires: 1993-01-08
Abstract
Abstract The vertical deflection amplifier in a television receiver is provided with negative feedback responsive to deflection current and amplifier voltage. The feedback, comprising passive filtering elements, alters the transfer characteristic of the amplifier to have the effect of a pass band about the sweep frequency to provide S-shaping of the sawtooth deflection current thereby correcting for ''''flat face'''' picture distortion.
Inventors
- 👤 J Knox
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 15:25
CPC Classifications
H; H03; H03K; H03K4/00; H03K4/06; H03K4/08; H03K4/48; H03K4/60; H03K4/69; H03K4/72; H03K4/725; H03K6/00; H03K6/04
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
125 words
In a television receiver having a cathode ray tube with vertical deflection windings for sweeping an image across the face of said cathode ray tube in a vertical direction, a vertical deflection drive circuit comprising: deflection wave generating means for generating a linear recurrent deflection wave of given frequency, an amplifier for applying said recurrent deflection wave to said vertical deflection windings in modified form, first feedback means responsive to deflection winding current to degeneratively control the transfer characteristic of said amplifier so that an S-shaped characteristic is imparted to said recurrent deflection wave, and second feedback means responsive to the voltage output of said amplifier to further degeneratively control the transfer characteristic of said amplifier and modify the effect of said first feedback means.
Claim 2
Dependent Claim
125 words
In a television receiver having a cathode ray tube with vertical deflection windings for sweeping an image across the face of said cathode ray tube in a vertical direction, a vertical deflection drive circuit comprising: deflection wave generating means for generating a linear recurrent deflection wave of given frequency, an amplifier for applying said recurrent deflection wave to said vertical deflection windings in modified form, first feedback means responsive to deflection winding current to degeneratively control the transfer characteristic of said amplifier so that an S-shaped characteristic is imparted to said recurrent deflection wave, and second feedback means responsive to the voltage output of said amplifier to further degeneratively control the transfer characteristic of said amplifier and modify the effect of said first feedback means.
Claim 3
Dependent Claim
32 words
The deflection drive circuit recited in claim 1 wherein said first feedback means includes a high pass filter and a low pass filter to impart a bandpass transfer characteristic to said amplifier.
Claim 4
Dependent Claim
71 words
The deflection drive circuit recited in claim 2 wherein said low pass filter comprises a capacitor responsive to deflection winding current at one terminal thereof and coupled at its other terminal both to an input of said amplifier and to a current return path including a resistor, and said high pass filter includes said resistor and a capacitor in series therewith, said high pass filter being coupled to said amplifier input.
Claim 5
Dependent Claim
31 words
The vertical deflection drive circuit recited in claim 3 wherein the values of said resistor and capacitors are selected to provide a peaked response for said amplifier below said given frequency.
Claim 6
Dependent Claim
49 words
The vertical deflection drive circuit recited in claim 4 wherein said second feedback means lowers the Q of the filters of said first feedback means to limit the effect of said first feedback means to shaping only the end portions of each sweep segment of said recurrent deflection waveform.
Claim 7
Dependent Claim
22 words
The vertical deflection drive circuit recited in claim 5 wherein said second feedback means establishes the DC bias level for said amplifier.
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) | 1977-10-14 | 1978-04-15 | 1978-10-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-14 | 1982-04-15 | 1982-10-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-14 | 1986-04-15 | 1986-10-15 | $7700.00 | Window Closed / Lapsed |