US3566181A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pin-cushion correction circuit
Assignee: Zenith Electronics LLC
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Filing: 1969-06-16
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Granted: 1971-02-23
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Expires: 1989-06-16
Abstract
Abstract Apparatus for effecting asymmetrical top and bottom pin cushion correction in a television receiver includes a core of saturable magnetic material upon which a signal winding and a control winding are physically oriented at right angles in order to preclude inductive coupling therebetween. An auxiliary winding, formed as an extension of the control winding, is positioned upon the core adjacent the signal winding and in an inductive coupling relation thereto. The signal winding is included in the output circuit of the vertical output stage. The control winding, which is energized from the horizontal output stage, cyclically varies the saturation of the core to modulate the vertical sweep signal flowing in the signal winding. This modulated signal is modified by a horizontal frequency component inductively coupled to the signal winding by the auxiliary winding. The inductively introduced horizontal component adjusts the relative peak amplitudes of the modulated vertical sweep signal to produce an asymmetrical vertical pin cushion correction which emphasizes beam deflection at the beginning of the sweep while attenuating beam deflection at the end of the sweep.
Inventors
- 👤 Raymond C Figlewicz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 11:00
CPC Classifications
H; H04; H04N; H04N3/00; H04N3/10; H04N3/16; H04N3/22; H04N3/23; H04N3/237
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
300 words
Apparatus for correcting pin cushion distortion in the scanning raster of a television receiver having a cathode-ray tube which includes beam forming and directing means and having a pair of deflection coils for deflecting the beam in mutually perpendicular directions to generate a two dimension raster, said apparatus comprising: a core of saturable magnetic material; a signal winding wound upon said core in a predetermined orientation relative to an axis of said core; means for coupling said signal winding to one of said deflection coils; means for applying to said signal winding and to said one deflection coil a first sweep current varying, in one cycle, from a maximum amplitude in one polarity through a zero value to a Maximum amplitude in an opposite polarity to establish beam scansion in one dimension of said raster; a control winding wound upon said core in a predetermined different orientation relative to the axis of said core; means for applying a second sweep current to said control winding for varying the saturation of said core and, thereby, the impedance of said signal winding to said first sweep current, so that said first sweep current is modulated by said second sweep current to develop a modulated sweep signal having oppositely polarized peak amplitudes for applying pin cushion correction to said one deflection coil; and means for modifying said modulated sweep signal comprising an auxiliary winding connected to said control winding and positioned upon said core in the same orientation as said signal winding and in an inductive coupling relation to said signal winding, for introducing a component of said second sweep current into said signal winding to adjust the relative peak amplitudes of said modulated sweep signal to emphasize beam deflection in one direction of said one raster dimension by said one deflection coil.
Claim 2
Dependent Claim
300 words
Apparatus for correcting pin cushion distortion in the scanning raster of a television receiver having a cathode-ray tube which includes beam forming and directing means and having a pair of deflection coils for deflecting the beam in mutually perpendicular directions to generate a two dimension raster, said apparatus comprising: a core of saturable magnetic material; a signal winding wound upon said core in a predetermined orientation relative to an axis of said core; means for coupling said signal winding to one of said deflection coils; means for applying to said signal winding and to said one deflection coil a first sweep current varying, in one cycle, from a maximum amplitude in one polarity through a zero value to a Maximum amplitude in an opposite polarity to establish beam scansion in one dimension of said raster; a control winding wound upon said core in a predetermined different orientation relative to the axis of said core; means for applying a second sweep current to said control winding for varying the saturation of said core and, thereby, the impedance of said signal winding to said first sweep current, so that said first sweep current is modulated by said second sweep current to develop a modulated sweep signal having oppositely polarized peak amplitudes for applying pin cushion correction to said one deflection coil; and means for modifying said modulated sweep signal comprising an auxiliary winding connected to said control winding and positioned upon said core in the same orientation as said signal winding and in an inductive coupling relation to said signal winding, for introducing a component of said second sweep current into said signal winding to adjust the relative peak amplitudes of said modulated sweep signal to emphasize beam deflection in one direction of said one raster dimension by said one deflection coil.
Claim 3
Dependent Claim
19 words
Apparatus as set forth in claim 1 in which said auxiliary winding constitutes an extension of said control winding.
Claim 4
Dependent Claim
71 words
Apparatus as set forth in claim 1 in which said core of magnetic material is formed as a hollow sleeve; said signal winding toroidally encloses said sleeve with its turns disposed essentially parallel to the central axis of said core; said control winding turns are oriented substantially normal to the turns of said signal winding; and said auxiliary winding turns are wound essentially parallel to the turns of said signal winding.
Claim 5
Dependent Claim
51 words
Apparatus as set forth in claim 1 in which said means for varying the saturation of said core amplitude modulates said first sweep current to develop said modulated sweep signal and said modifying means amplifies one amplitude of said modulated signal and attenuates the oppositely polarized amplitude of said modulated signal.
Claim 6
Dependent Claim
55 words
Apparatus as set forth in claim 1 in which said pair of deflection coils comprise the vertical and horizontal deflection coils of said receiver; said signal winding comprises a pair of coils connected in series with said vertical deflection coil; and said control winding and said auxiliary winding are coupled to said horizontal deflection coil.
Claim 7
Dependent Claim
26 words
Apparatus as set forth in claim 5 further comprising means for tuning said signal winding to resonate at the frequency of the horizontal deflection system system.
Claim 8
Dependent Claim
87 words
Apparatus as set forth in claim 4 in which said first sweep current varies from a maximum amplitude in a negative polarity to a maximum amplitude in a positive polarity to establish beam scansion in the vertical dimension of said raster; said modulated sweep signal varies from a maximum amplitude in a negative polarity to a maximum amplitude in a positive polarity; and said modifying means amplifies said negatively polarized amplitude of said modulated sweep signal and attenuates said positively polarized amplitude of said modulated sweep signal.
Claim 9
Dependent Claim
216 words
Apparatus for correcting distortion in the scanning raster of a television receiver having a cathode-ray tube which includes beam forming and directing means and having a pair of deflection coils for deflecting the beam in mutually perpendicular directions to generate a two dimension raster, said apparatus comprising: a modulator coupled to one of said deflection coils; means for applying to said modulator a sweep signal of predetermined frequency and varying, in one cycle, from a maximum amplitude in one polarity through a zero value to a maximum amplitude in an opposite polarity to establish beam scansion in one dimension of said raster; means for applying a second signal of predetermined different frequency to said modulator for modulating said sweep signal to develop a modulated sweep signal for application to said one deflection coil, said modulated signal Having oppositely phased peak amplitudes at opposite ends of the sweep cycle; and means for additively superimposing a component of said second signal upon said modulated sweep signal to amplify the peak amplitude of said modulated sweep signal at one end of the sweep cycle while attenuating the peak amplitude of said modulated sweep signal at the opposite end of the sweep cycle to emphasize beam deflection in one direction of said one raster dimension by said one deflection coil.
Claim 10
Dependent Claim
216 words
Apparatus for correcting distortion in the scanning raster of a television receiver having a cathode-ray tube which includes beam forming and directing means and having a pair of deflection coils for deflecting the beam in mutually perpendicular directions to generate a two dimension raster, said apparatus comprising: a modulator coupled to one of said deflection coils; means for applying to said modulator a sweep signal of predetermined frequency and varying, in one cycle, from a maximum amplitude in one polarity through a zero value to a maximum amplitude in an opposite polarity to establish beam scansion in one dimension of said raster; means for applying a second signal of predetermined different frequency to said modulator for modulating said sweep signal to develop a modulated sweep signal for application to said one deflection coil, said modulated signal Having oppositely phased peak amplitudes at opposite ends of the sweep cycle; and means for additively superimposing a component of said second signal upon said modulated sweep signal to amplify the peak amplitude of said modulated sweep signal at one end of the sweep cycle while attenuating the peak amplitude of said modulated sweep signal at the opposite end of the sweep cycle to emphasize beam deflection in one direction of said one raster dimension by said one deflection coil.
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) | 1974-02-22 | 1974-08-24 | 1975-02-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-02-22 | 1978-08-24 | 1979-02-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-02-22 | 1982-08-24 | 1983-02-23 | $7700.00 | Window Closed / Lapsed |