US3979700A
Expired / Lapsed
US
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Video processor
Assignee: International Telephone and Telegraph Corp
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Filing: 1974-08-01
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Granted: 1976-09-07
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Expires: 1994-08-01
Abstract
Abstract A video signal processor for repetitive line data, such as the typical TV horizontal scan line. An acoustic surface wave delay line comprising a piezoelectric substrate with an input wave launcher and a plurality of interdigital taps is provided. The video signal line "fits" in the overall delay and electronic circuits (preferably of the integrated circuit type) are connected to the taps. Individual taps each have a weighting amplifier weighting from line center to early and late extremes, and their outputs are summed on the same basis. The sum has a polarity indicative of the signal line centroid sense vis-a-vis the line center and has an amplitude indicative of centroid spacing with respect to said line center.
Inventors
- 👤 John C. Groce
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 06:23
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/14; H03; H03H; H03H9/00; H03H9/02; H03H9/02535; H03H9/02543; H03H9/02566; H03H9/46; H03H9/64; H03H9/6403
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
242 words
A video signal processor comprising: a piezoelectric substrate having at least one elongated dimension; first means for launching a surface acoustic wave along a surface of said piezoelectric substrate, said first means being responsive to an input signal representative of a video signal train; second means comprising a plurality N of interdigital electrode sensor pairs substantially uniformly distributed along the surface of said piezoelectric substrate so as to each receive an electric signal as said surface acoustic wave progresses, said sensor pairs being contained within said elongated dimension over a sensing length equal to the distance traveled by the leading edge of said surface wave over the duration of said video signal train; third means comprising N/2 first summation circuits, each of said summation circuits being connected to sum the signal generated at a discrete one of said pair sensors in the first half of said N sensor pairs with that generated by a corresponding sensor pair spaced by the same number of said pairs from the center of said plurality of N sensor pairs within the second half of said sensor pairs; fourth means within said third means for inverting the polarity of the detected signal from each of said sensor pairs in said second half of said N sensor pairs before application to said first summation circuits; and fifth means comprising a second summation circuit connected to sum the outputs of said first summation circuits to provide an output signal.
Claim 2
Dependent Claim
242 words
A video signal processor comprising: a piezoelectric substrate having at least one elongated dimension; first means for launching a surface acoustic wave along a surface of said piezoelectric substrate, said first means being responsive to an input signal representative of a video signal train; second means comprising a plurality N of interdigital electrode sensor pairs substantially uniformly distributed along the surface of said piezoelectric substrate so as to each receive an electric signal as said surface acoustic wave progresses, said sensor pairs being contained within said elongated dimension over a sensing length equal to the distance traveled by the leading edge of said surface wave over the duration of said video signal train; third means comprising N/2 first summation circuits, each of said summation circuits being connected to sum the signal generated at a discrete one of said pair sensors in the first half of said N sensor pairs with that generated by a corresponding sensor pair spaced by the same number of said pairs from the center of said plurality of N sensor pairs within the second half of said sensor pairs; fourth means within said third means for inverting the polarity of the detected signal from each of said sensor pairs in said second half of said N sensor pairs before application to said first summation circuits; and fifth means comprising a second summation circuit connected to sum the outputs of said first summation circuits to provide an output signal.
Claim 3
Dependent Claim
105 words
Apparatus according to claim 1 including sixth means for weighting the signal from each of said sensor pairs before application to said first summation circuits of said third means, said sixth means providing greatest weighting for sensor pairs farthest from the center of said plurality of N sensor pairs and least weighting for sensor pairs closest to the center of said plurality of N sensor pairs, the polarity and amplitude of said fifth means output signal thereby corresponding to the sense of the location of the centroid of said signal train and spacing with respect to said center of said plurality of sensor pairs, respectively.
Claim 4
Dependent Claim
72 words
Apparatus according to claim 2 in which said signal train is defined as corresponding to and having the duration of a scan line in a repetitive scanning system and said sixth means comprises N amplifiers each responsive to the signal output of a corresponding sensor pair, said amplifiers each providing a predetermined gain for each signal pair inputed to each of said first summers of said third means to produce said weighting.
Claim 5
Dependent Claim
83 words
Apparatus according to claim 1 in which said first means includes a radio frequency source, means for modulating said radio frequency source in accordance with said video signal train as a signal to be processed, and means including at least one pair of interdigital finger electrodes forming an input transducer connected to the modulated output of said radio frequency source and mounted at one end of said piezoelectric substrate outside said sensing length, but parallel to said sensor pairs of said second means.
Claim 6
Dependent Claim
83 words
Apparatus according to claim 3 in which said first means includes a radio frequency source, means for modulating said radio frequency source in accordance with said video signal train as a signal to be processed, and means including at least one pair of interdigital finger electrodes forming an input transducer connected to the modulated output of said radio frequency source and mounted at one end of said piezoelectric substrate outside said sensing length, but parallel to said sensor pairs of said second means.
Claim 7
Dependent Claim
107 words
Apparatus according to claim 4 in which said interdigital electrode sensor pairs are defined as including finger electrode pairs, and these and said finger electrodes of said transducer are deposited as conductive film on said piezoelectric substrate to a depth ranging between 1000 and 2000 angstroms approximately, said fingers have a width in the direction of said elongated dimension of approximately one quarter wavelength, a center-to-center spacing of approximately one half wavelength in the direction of said elongated dimension, and a length measured transverse to said elongated dimension on the order of 80 wavelengths, said wavelength measurements being based on the frequency of said ratio frequency source.
Claim 8
Dependent Claim
27 words
Apparatus according to claim 1 in which N is a sufficiently large number to provide a resolution on the order of 500 elements over said sensing length.
Claim 9
Dependent Claim
83 words
Apparatus according to claim 5 including an insulating base plane and semiconductor substrate, said piezoelectric substrate and said semiconductor substrate being mounted in juxtaposition along one elongated dimension edge of said piezoelectric substrate, and in which at least portions of said third, fourth and fifth means are provided as integrated circuits on said semiconductor substrate, thereby to provide direct electrical connections at least from said interdigital electrodes of said said sensor pairs to the circuits of said means provided on said semiconductor substrate.
Claim 10
Dependent Claim
30 words
Apparatus according to claim 5 in which said radio frequency source has a frequency at least in the VHF domain in order to minimize the physical size of said apparatus.
Claim 11
Dependent Claim
31 words
Apparatus according to claim 6 in which the material of said conductive film is selected from a group comprising aluminum, gold and chrome-gold, and said piezoelectric substrate material is lithium niobate.
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) | 1979-09-07 | 1980-03-08 | 1980-09-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-09-07 | 1984-03-08 | 1984-09-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-09-07 | 1988-03-08 | 1988-09-07 | $7700.00 | Window Closed / Lapsed |