US3649870A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pincushion correction circuit utilizing a dc-regulated power supply
Assignee: Zenith Electronics LLC
•
Filing: 1970-05-01
•
Granted: 1972-03-14
•
Expires: 1990-05-01
Abstract
Abstract A circuit for correcting side pincushion distortion in a color television receiver having a cathode-ray tube and associated horizontal and vertical deflection circuits for generating a raster thereon. The circuit comprises a power supply for developing a DC potential and a regulating circuit for the supply which includes a transistor device, the collector-emitter path of which is serially interposed between the output of the supply and the energizing electrode of an output transistor in the horizontal deflection circuit. An integrating network, coupled to the vertical deflection circuit, derives a parabolic wave signal which is applied to the DC potential translated by the regulating transistor. The parabola-modulated DC potential applied to the energizing electrode of the horizontal output transistor changes the magnitude of horizontal scanning current in the horizontal deflection circuit parabolically as the electron beams are vertically deflected from the top of the raster to the bottom.
Inventors
- 👤 William W Maulsby
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 18:05
CPC Classifications
H; H04; H04N; H04N3/00; H04N3/10; H04N3/16; H04N3/22; H04N3/23; H04N3/233
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
299 words
In a television receiver comprising a cathode-ray tube which includes electron beam forming and directing means, a horizontal deflection circuit including an electron control device having an energizing electrode and a vertical deflection circuit, said deflection circuits conjointly deflecting said beam in mutually perpendicular directions to generate a two-dimension raster, a circuit for correcting pincushion distortion in the sides of said raster comprising: a power supply for generating a direct current potential for energizing said horizontal deflection circuit; a control circuit for maintaining the output of said power supply substantially constant, said control circuit comprising a regulating electron control device for translating said direct current potential and having an input electrode connected to the output of said power supply, a control electrode and an output electrode, and an error-responsive electron control device for monitoring the direct current potential translated by said regulating device, said error-responsive control device having an input terminal connected to said output electrode of said regulating device, an output terminal coupled to said control electrode of said regulating device and a third terminal; a waveshaping circuit coupled to said vertical deflection circuit for deriving therefrom a parabolic wave signal varying at the vertical deflection frequency; means for coupling said wave-shaping circuit to said input terminal of said error-responsive control device to apply said parabolic signal to said control electrode of said regulating device to modulate said direct current potential translated by said regulating device; and means coupled to said output electrode of said control device for applying said parabola-modulated direct current potential to said energizing electrode of said electron control device included in said horizontal deflection circuit for changing the magnitude of horizontal scanning current in said horizontal deflection circuit parabolically as said beam is vertically deflected from the top of said raster to the bottom.
Claim 2
Dependent Claim
299 words
In a television receiver comprising a cathode-ray tube which includes electron beam forming and directing means, a horizontal deflection circuit including an electron control device having an energizing electrode and a vertical deflection circuit, said deflection circuits conjointly deflecting said beam in mutually perpendicular directions to generate a two-dimension raster, a circuit for correcting pincushion distortion in the sides of said raster comprising: a power supply for generating a direct current potential for energizing said horizontal deflection circuit; a control circuit for maintaining the output of said power supply substantially constant, said control circuit comprising a regulating electron control device for translating said direct current potential and having an input electrode connected to the output of said power supply, a control electrode and an output electrode, and an error-responsive electron control device for monitoring the direct current potential translated by said regulating device, said error-responsive control device having an input terminal connected to said output electrode of said regulating device, an output terminal coupled to said control electrode of said regulating device and a third terminal; a waveshaping circuit coupled to said vertical deflection circuit for deriving therefrom a parabolic wave signal varying at the vertical deflection frequency; means for coupling said wave-shaping circuit to said input terminal of said error-responsive control device to apply said parabolic signal to said control electrode of said regulating device to modulate said direct current potential translated by said regulating device; and means coupled to said output electrode of said control device for applying said parabola-modulated direct current potential to said energizing electrode of said electron control device included in said horizontal deflection circuit for changing the magnitude of horizontal scanning current in said horizontal deflection circuit parabolically as said beam is vertically deflected from the top of said raster to the bottom.
Claim 3
Dependent Claim
18 words
A pincushion-correcting circuit as set forth in claim 1 in which all said electron control devices comprise transistors.
Claim 4
Dependent Claim
24 words
A pincushion-correcting circuit as set forth in claim 1 in which said waveshaping circuit includes an integrating network for deriving said parabolic wave signal.
Claim 5
Dependent Claim
31 words
A pincushion-correcting circuit as set forth in claim 1 in which said control circuit further includes means for maintaining said third terminal of said error-responsive device at a fixed reference potential.
Claim 6
Dependent Claim
66 words
A pincushion-correcting circuit as set forth in claim 2 in which the base, emitter and collector elements of said regulating transistor form the control, output and input electrodes, respectively, of said regulating transistor so that the emitter-collector path of said regulating transistor, in response to said parabolic signal applied to said base element, comprises an adjustable series impedance across which said direct current potential is translated.
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) | 1975-03-14 | 1975-09-13 | 1976-03-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-03-14 | 1979-09-13 | 1980-03-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-03-14 | 1983-09-13 | 1984-03-14 | $7700.00 | Window Closed / Lapsed |