Patent EP0361152A2 successfully refreshed from Google Patents.
US3944879A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pin cushion distortion correction circuit
Assignee: Sony Corp
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Filing: 1974-05-16
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Granted: 1976-03-16
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Expires: 1994-05-16
Abstract
Abstract A pin cushion distortion correction circuit is disclosed in which a parallel circuit of a resistor and a diode is inserted into the base circuit of a driving transistor of a saturable reactor for the correction of left and right pin cushion distortions to increase a correction current corresponding to the central portion of a video screen.
Inventors
- 👤 Masao Suzuki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 00:51
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
133 words
A correction circuit for correction of pin cushion distortion of the sides of a television raster, said circuit comprising: A. a horizontal deflection circuit; B. a source of signal synchronous with the vertical deflection frequency of said raster, said signal having a generally parabolic waveform; C. a saturable reactor connected to said deflection circuit to modify the horizontal deflection current to correct said pin cushion distortion; and D. a coupling circuit comprising: 1. an impedance connected between said signal source and said reactor to control the amplitude of said signal applied to control said reactor, and 2. unidirectionally conductive means connected to said impedance to control the effective value thereof during peak values of said signal to modify the waveform of said signal in order to correct for non-linear response of said reactor.
Claim 2
Dependent Claim
133 words
A correction circuit for correction of pin cushion distortion of the sides of a television raster, said circuit comprising: A. a horizontal deflection circuit; B. a source of signal synchronous with the vertical deflection frequency of said raster, said signal having a generally parabolic waveform; C. a saturable reactor connected to said deflection circuit to modify the horizontal deflection current to correct said pin cushion distortion; and D. a coupling circuit comprising: 1. an impedance connected between said signal source and said reactor to control the amplitude of said signal applied to control said reactor, and 2. unidirectionally conductive means connected to said impedance to control the effective value thereof during peak values of said signal to modify the waveform of said signal in order to correct for non-linear response of said reactor.
Claim 3
Dependent Claim
13 words
The correction circuit of claim 1 in which said impedance is a resistor.
Claim 4
Dependent Claim
15 words
The correction circuit of claim 2 in which said unidirectionally conductive device is a diode.
Claim 5
Dependent Claim
85 words
The correction circuit of claim 3 in which said coupling circuit comprises a transistor comprising: A. an output circuit connected to said reactor to control current flow therethrough; and B. an input circuit connected to said resistor and said diode, said diode being polarized to be conductive when said parabolic signal is in excess of a predetermined amount said diode reducing the effective resistance of said resistor during such periods of conductivity to increase the amplitude of said parabolic signal applied to said input circuit.
Claim 6
Dependent Claim
17 words
The correction circuit of claim 4 in which said resistor and said diode are connected in parallel.
Claim 7
Dependent Claim
33 words
The correction circuit of claim 5 in which said coupling circuit comprises a second resistor connected in series with said diode to form a series circuit connected in parallel with said first-named resistor.
Claim 8
Dependent Claim
60 words
The correction circuit of claim 6 comprising, in addition, a second parallel circuit comprising: A. a third resistor; and B. a second series circuit comprising a capacitor connected in series with a second diode, said second series circuit being connected in parallel with said third resistor, and said second parallel circuit being connected in series with said first-named parallel circuit.
Claim 9
Dependent Claim
16 words
The correction circuit of claim 7 comprising a charge-limiting resistor connected in series with said capacitor.
Claim 10
Dependent Claim
23 words
The correction circuit of claim 8 comprising a discharge resistor connected in parallel with said capacitor and in series with said second diode.
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) | 1979-03-16 | 1979-09-15 | 1980-03-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-16 | 1983-09-15 | 1984-03-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-16 | 1987-09-15 | 1988-03-16 | $7700.00 | Window Closed / Lapsed |