US3794877A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Jitter immune transistorized vertical deflection circuit
Assignee: RCA Licensing Corp
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Filing: 1972-03-30
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Granted: 1974-02-26
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Expires: 1992-03-30
Abstract
Abstract U.S. Pat. No. 3,684,920 issued on Aug. 15, 1972 and based on U.S. Patent Application Serial No. 37,668, filed May 15, 1970, describes a transistor deflection circuit employing an output stage of class B, push-pull complementary symmetry type and a Miller integrator approach for the sawtooth wave generation. This invention describes a modification to the discharge circuitry thereof to improve the vertical deflection stability in the presence of spurious pulses which tend to undesirably and randomly trigger and/or retrigger the discharge switch. An additional ''''blanker'''' transistor is employed to sense the voltage across the vertical yoke winding so as to bypass the spurious signals away from the discharge switch during the vertical retrace interval when the danger exists that the deflection circuits will be falsely triggered.
Inventors
- 👤 L Smith
- 👤 D Neal
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 10:04
CPC Classifications
H; H03; H03K; H03K4/00; H03K4/06; H03K4/08; H03K4/48; H03K4/60; H03K4/69; H03K4/71; H04; H04N; H04N5/00; H04N5/14; H04N5/21; H04N5/213
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
324 words
In a television receiver of the type comprising: a. a cathode-ray kinescope; b. a vertical deflection circuit including a capacitor and a current source from which said capacitor is charged in developing a vertical deflection rate signal for the electron beam of said kinescope; c. a vertical deflection yoke winding coupled to an output terminal of said deflection circuit, with flyback pulses appearing across said winding during periodically recurring retrace intervals; d. a first transistor having an output electrode direct current conductively connected to an input terminal of said deflection circuit, with said transistor being rendered nonconductive during recurring trace intervals to permit the development of said vertical deflection rate signal by said capacitor and being rendered conductive during said recurring retrace intervals to inhibit the development of said deflection rate signal; and e. a composite synchronizing signal source; the combination therewith of: means for supplying vertical deflection rate trigger pulses to said first transistor for initiating the conduction thereof in response to said trigger pulses, said means including a signal path coupled between said synchronizing signal source and an input electrode of said first transistor, said signal path including as a serial element thereof a first impedance; a second transistor having a collector electrode coupled to a terminal of said first impedance remote from said source, an emitter electrode coupled to a point of reference potential, and a base electrode; means coupled to said deflection yoke winding for applying a voltage waveform appearing across deflection yoke winding to the base electrode of said second transistor to initiate conduction of said second transistor subsequent to said first transistor during each of said retrace intervals, the conduction of said second transistor persisting through the remainder of each said retrace interval and the initial portion of the succeeding trace interval, to thereby bypass spurious trigger pulses occurring after said first transistor has initially been rendered conductive through said second transistor and away from said first transistor.
Claim 2
Dependent Claim
324 words
In a television receiver of the type comprising: a. a cathode-ray kinescope; b. a vertical deflection circuit including a capacitor and a current source from which said capacitor is charged in developing a vertical deflection rate signal for the electron beam of said kinescope; c. a vertical deflection yoke winding coupled to an output terminal of said deflection circuit, with flyback pulses appearing across said winding during periodically recurring retrace intervals; d. a first transistor having an output electrode direct current conductively connected to an input terminal of said deflection circuit, with said transistor being rendered nonconductive during recurring trace intervals to permit the development of said vertical deflection rate signal by said capacitor and being rendered conductive during said recurring retrace intervals to inhibit the development of said deflection rate signal; and e. a composite synchronizing signal source; the combination therewith of: means for supplying vertical deflection rate trigger pulses to said first transistor for initiating the conduction thereof in response to said trigger pulses, said means including a signal path coupled between said synchronizing signal source and an input electrode of said first transistor, said signal path including as a serial element thereof a first impedance; a second transistor having a collector electrode coupled to a terminal of said first impedance remote from said source, an emitter electrode coupled to a point of reference potential, and a base electrode; means coupled to said deflection yoke winding for applying a voltage waveform appearing across deflection yoke winding to the base electrode of said second transistor to initiate conduction of said second transistor subsequent to said first transistor during each of said retrace intervals, the conduction of said second transistor persisting through the remainder of each said retrace interval and the initial portion of the succeeding trace interval, to thereby bypass spurious trigger pulses occurring after said first transistor has initially been rendered conductive through said second transistor and away from said first transistor.
Claim 3
Dependent Claim
92 words
The combination of claim 1 wherein said vertical deflection circuit includes an output stage comprising third and fourth transistors of opposite conductivity type having their emitter electrodes connected to said output terminal, their base electrodes connected to an input terminal, and their respective collector electrodes connected to a unidirectional voltage supply terminal and said point of reference potential, respectively, with one of said third and fourth transistors conducting during the initial half of recurring trace intervals and wiTh the other of said third and fourth transistors conducting during the final half thereof.
Claim 4
Dependent Claim
86 words
The combination of claim 1 wherein said first impedance comprises a resistor, and wherein said means for supplying vertical deflection rate trigger pulses includes integrator circuit means for reducing the horizontal synchronizing component of composite synchronizing signals from said source and for selecting the vertical synchronizing component of said composite signals to the relative exclusion of said horizontal synchronizing component, said integrator circuit means including said resistor and a second capacitor coupled between the collector electrode of said second transistor and said point of reference potential.
Claim 5
Dependent Claim
58 words
The combination of claim 2 wherein said vertical deflection circuit further includes a fifth transistor having an output electrode direct current conductively connected to said input terminal of said deflection output stage, with said fifth transistor being conductive during said recurring trace intervals and being nonconductive during said retrace intervals in response to said vertical deflection rate signal.
Claim 6
Dependent Claim
284 words
In a television receiver including a source of composite synchronizing signals comprising a horizontal deflection synchronizing component and a vertical deflection synchronizing component, a vertical deflection circuit comprising, in combination: a first capacitor; a source of charging current coupled to said first capacitor; a discharge transistor coupled to said first capacitor for discharging said first capacitor when rendered conducting, said first capacitor being subject to charging by current from said charging current source when said discharge transistor is non-conducting, said discharge transistor having a control electrode; a deflection yoke winding; a deflection wave amplifier responsive to a voltage was developed by the charging of said first capacitor by said current and the discharging of said first capacitor by said discharge transistor, said deflection wave amplifier having an output circuit including said deflection yoke winding; an integrating circuit coupled to said source of composite synchronizing signals and including the series combination of a resistor and a second capacitor; means, including a signal path between said control electrode of said discharge transistor and the junction of said resistor and second capacitor of said integrating circuit, for rendering said discharge transistor responsive to said vertical synchronizing component as developed across said second capacitor; a second transistor having a base electrode, and having an emitter-collector path shunted across said second capacitor; means, including a coupling between said output circuit and said base electrode of said second transistor, for causing conduction in said emitter-collector path during a terminal portion of each interval of discharging of said first capacitor by said discharge transistor and during an initial portion of each succeeding interval of charging of said first capacitor in response to a voltage waveform developed across said deflection yoke winding.
Claim 7
Dependent Claim
284 words
In a television receiver including a source of composite synchronizing signals comprising a horizontal deflection synchronizing component and a vertical deflection synchronizing component, a vertical deflection circuit comprising, in combination: a first capacitor; a source of charging current coupled to said first capacitor; a discharge transistor coupled to said first capacitor for discharging said first capacitor when rendered conducting, said first capacitor being subject to charging by current from said charging current source when said discharge transistor is non-conducting, said discharge transistor having a control electrode; a deflection yoke winding; a deflection wave amplifier responsive to a voltage was developed by the charging of said first capacitor by said current and the discharging of said first capacitor by said discharge transistor, said deflection wave amplifier having an output circuit including said deflection yoke winding; an integrating circuit coupled to said source of composite synchronizing signals and including the series combination of a resistor and a second capacitor; means, including a signal path between said control electrode of said discharge transistor and the junction of said resistor and second capacitor of said integrating circuit, for rendering said discharge transistor responsive to said vertical synchronizing component as developed across said second capacitor; a second transistor having a base electrode, and having an emitter-collector path shunted across said second capacitor; means, including a coupling between said output circuit and said base electrode of said second transistor, for causing conduction in said emitter-collector path during a terminal portion of each interval of discharging of said first capacitor by said discharge transistor and during an initial portion of each succeeding interval of charging of said first capacitor in response to a voltage waveform developed across said deflection yoke winding.
Claim 8
Dependent Claim
45 words
Apparatus in accordance with claim 5 also including: a second integrating circuit, coupled to the junction of said first-named resistor and second capacitor, and including the series combination of a second resistor and a third capacitor, said second resistor being included in said signal path.
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) | 1977-02-25 | 1977-08-27 | 1978-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-25 | 1981-08-27 | 1982-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-25 | 1985-08-27 | 1986-02-26 | $7700.00 | Window Closed / Lapsed |