US3571653A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Horizontal pincushion correction circuit
Assignee: Motorola Solutions Inc
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Filing: 1967-08-18
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Granted: 1971-03-23
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Expires: 1987-08-18
Abstract
Abstract The circuit includes means to develop a parabolic signal at the vertical sweep frequency for controlling the bias on the output device in the horizontal sweep system. The polarity of the signal is such as to cause increasing conduction of the device towards the top and bottom of the raster and since the output device mainly controls scan on the right side of the raster, this serves to increase distortion on the right side in order to approach the greater distortion which normally appears on the left side. The circuit further includes means to simultaneously correct the distortion on both sides and straighten the raster.
Inventors
- 👤 Robert B Hansen
- 👤 James P Mcshane Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 03:56
CPC Classifications
H; H04; H04N; H04N3/00; H04N3/10; H04N3/16; H04N3/22; H04N3/23; H04N3/233
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
238 words
In a television receiver having a cathode ray tube, horizontal and vertical yokes for deflecting an electron beam thereof to form a raster having a top, a bottom and first and second side portions, the cathode ray tube and the horizontal yoke having characteristics to cause the first side portion to bend inwardly to a greater extent than the second side portion, a vertical sweep system for applying sweep signals at a vertical frequency to the vertical yoke, a horizontal sweep system including in combination; a current supply circuit including first circuit means coupled to the horizontal yoke for applying an initial portion of a sawtooth current signal to the horizontal yoke for sweeping the beam across the first side portion of the raster, the supply circuit further including an electron control device for applying a terminal portion of the sawtooth current signal to the horizontal yoke for sweeping the beam across the second side portion, second circuit means coupled between the vertical sweep system and said electron control device to develop a parabolic signal at the vertical frequency of a polarity with respect to the conductivity of said electron control device to parabolically increase the conduction of said device towards the top and bottom of the raster, to thereby increase the inward bending of the second side portion, and means coupled to the horizontal sweep system to simultaneously straighten both side portions by a substantially equal amount.
Claim 2
Dependent Claim
238 words
In a television receiver having a cathode ray tube, horizontal and vertical yokes for deflecting an electron beam thereof to form a raster having a top, a bottom and first and second side portions, the cathode ray tube and the horizontal yoke having characteristics to cause the first side portion to bend inwardly to a greater extent than the second side portion, a vertical sweep system for applying sweep signals at a vertical frequency to the vertical yoke, a horizontal sweep system including in combination; a current supply circuit including first circuit means coupled to the horizontal yoke for applying an initial portion of a sawtooth current signal to the horizontal yoke for sweeping the beam across the first side portion of the raster, the supply circuit further including an electron control device for applying a terminal portion of the sawtooth current signal to the horizontal yoke for sweeping the beam across the second side portion, second circuit means coupled between the vertical sweep system and said electron control device to develop a parabolic signal at the vertical frequency of a polarity with respect to the conductivity of said electron control device to parabolically increase the conduction of said device towards the top and bottom of the raster, to thereby increase the inward bending of the second side portion, and means coupled to the horizontal sweep system to simultaneously straighten both side portions by a substantially equal amount.
Claim 3
Dependent Claim
52 words
The television receiver set forth in claim 1 wherein the vertical sweep system includes third circuit means to supply an output signal at the vertical sweep frequency, said second circuit means being coupled to said third circuit means and including an integrating circuit to convert said output signal into said parabolic signal.
Claim 4
Dependent Claim
47 words
The television receiver set forth in claim 2 wherein said integrating circuit includes resistor means and capacitor means coupled in series between said third circuit means and a reference potential, and means coupling the junction of said resistor means and capacitor means to said electron control device.
Claim 5
Dependent Claim
46 words
The television receiver set forth in claim 1 wherein said electron control device includes a vacuum tube having a control grip coupled to said second circuit means, with said parabolic signal having a minimum value at the center thereof and maximum values at the ends thereof.
Claim 6
Dependent Claim
47 words
The television receiver set forth in claim 1 wherein said horizontal sweep system further including a bias circuit coupled to said electron device to provide a quiescent direct current voltage therefor, with said parabolic signal from said second circuit means changing said voltage at a parabolic rate.
Claim 7
Dependent Claim
36 words
The television receiver set forth in claim 1 wherein said first circuit means includes a damper diode effectively coupled across said electron control device and poled to conduct current in a direction opposite to said device.
Claim 8
Dependent Claim
56 words
The television receiver set forth in claim 1 wherein said means to simultaneously straighten boTh side portions includes a saturable inductor coupled in series with the horizontal yoke, and third circuit means coupled between the vertical sweep system and said inductor and including an integrating network to parabolically change the inductance thereof at the vertical frequency.
References Cited (Backward Citations)
US2842709A
Cited
US2758248A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-03-22 | 1974-09-21 | 1975-03-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-22 | 1978-09-21 | 1979-03-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-22 | 1982-09-21 | 1983-03-23 | $7700.00 | Window Closed / Lapsed |