Patent US3596064A successfully refreshed from Google Patents.
US3596064A
Expired / Lapsed
US
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Electronic line skew corrector
Assignee: Ampex Corp
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Filing: 1969-09-15
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Granted: 1971-07-27
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Expires: 1989-09-15
Abstract
Abstract Circuit for obtaining a wide-band line-tracking error signal prior to the dominant time constant of the line-tracking servo. A difference circuit introduces the line-tracking error signal, which includes a skew error signal, to a synchronous detector operating at the beam zigzag rate. The error signal recovered by the detector, is indicative of skew and is used to control a variable amplitude variable polarity zigzag waveform which is, in turn, applied to the beam deflection system in a direction perpendicular to the tracked lines to thus correct for skew. The invention described herein was made in the course of a contract with the United States Department of the Army.
Inventors
- 👤 Bob V Markevitch
- 👤 David K Fibush
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 03:44
CPC Classifications
G; G11; G11C; G11C13/00; G11C13/04
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
181 words
A wide-band line-tracking system for correcting for skew errors experienced in a zigzag line recording process, including beam deflector means, comprising the combination of; circuit means for extracting a wide-band line-tracking error signal commensurate with the tracking error at the zigzag rate, which signal includes a component of skew error signal; detector means coupled to the circuit means for recovering the skew error signal which is indicative of the degree of polarity of skew error; waveform generating means operatively coupled to the detector means and thence to the beam deflector means to introduce a selected waveform signal to the latter means in a direction perpendicular to the lines being tracked, and, in synchronism with the zigzag line rate; reference frequency means coupled to the detector means and the waveform generating means to provide control signals thereto for synchronously operating the detector and generating means relative to the line scan rate of the beam deflector means; and dominant time constant means coupled between the detector means and the waveform generating means to determine the phase at the closing frequency of the system.
Claim 2
Dependent Claim
181 words
A wide-band line-tracking system for correcting for skew errors experienced in a zigzag line recording process, including beam deflector means, comprising the combination of; circuit means for extracting a wide-band line-tracking error signal commensurate with the tracking error at the zigzag rate, which signal includes a component of skew error signal; detector means coupled to the circuit means for recovering the skew error signal which is indicative of the degree of polarity of skew error; waveform generating means operatively coupled to the detector means and thence to the beam deflector means to introduce a selected waveform signal to the latter means in a direction perpendicular to the lines being tracked, and, in synchronism with the zigzag line rate; reference frequency means coupled to the detector means and the waveform generating means to provide control signals thereto for synchronously operating the detector and generating means relative to the line scan rate of the beam deflector means; and dominant time constant means coupled between the detector means and the waveform generating means to determine the phase at the closing frequency of the system.
Claim 3
Dependent Claim
40 words
The system of claim 1 wherein the detector means includes circuit means for providing a direct current output whose amplitude is representative of the magnitude of the skew error and whose polarity is indicative of the direction of skew error.
Claim 4
Dependent Claim
48 words
The system of claim 2 wherein the waveform generating means includes circuit means for providing a triangle waveform output in response to the reference frequency means, whose amplitude is proportional to the magnitude of the skew error and whose polarity is indicative of the direction of skew error.
Claim 5
Dependent Claim
32 words
The system of claim 3 wherein the reference frequency means provides a square wave output voltage which has a frequency of one-half the line repetition frequency of the zigzag line recording process.
Claim 6
Dependent Claim
53 words
The system of claim 3 wherein the circuit means for providing a triangle waveform output includes switch means operatively coupled to the detector means and responsive to the reference frequency means for providing a selected output which alternates in polarity with an amplitude proportional to the skew error and at the zigzag rate.
Claim 7
Dependent Claim
46 words
The system of claim 5 further including amplifier means operatively coupled to the detector means for increasing the gain of the direct current output, and impedance matching means operatively coupled to the amplifier means to provide impedance matching between the detector means and circuits coupled thereto.
Claim 8
Dependent Claim
70 words
The system of claim 5 wherein the waveform-generating means includes inverting amplifier means coupled to the reference frequency means to provide an inverted control signal therefrom, and summing junction means coupled to the inverting amplifier means and to the switch means to add the outputs therefrom, the output of the summing junction means being determined by the larger of the outputs from the switch means and the inverting amplifier means.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-07-26 | 1975-01-25 | 1975-07-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-07-26 | 1979-01-25 | 1979-07-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-07-26 | 1983-01-25 | 1983-07-27 | $7700.00 | Window Closed / Lapsed |