US3848155A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Crt linear sweep control circuit
Assignee: Cogar Corp
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Filing: 1971-10-01
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Granted: 1974-11-12
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Expires: 1991-10-01
Abstract
Abstract A CRT linear sweep control circuit. A transistor switch is used in a conventional way to cause a sweep current to flow through a deflecting coil. An auxiliary ramp current is generated and injected into the coil toward the end of the sweep. The injected ramp current compensates for the non-linear nature of the main sweep current waveform toward the end of the sweep. The circuit for generating the additional ramp current is synchronized to the retrace pulses of the main sweep.
Inventors
- 👤 R Titus
- 👤 W Kelly
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 17:33
CPC Classifications
H; H03; H03K; H03K4/00; H03K4/06; H03K4/08; H03K4/90; G; G01; G01R; G01R13/00; G01R13/20; G01R13/22; G01R13/24
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
191 words
A sweep circuit for causing a linear sweep current to flow through a deflecting coil comprising means for applying a step voltage across said coil to initiate each sweep waveform, the main sweep current which flows through the coil responsive to the application of said step voltage being non-linear toward the end of the sweep waveform as a result of resistance in the coil circuit, and means for generating a ramp current and injecting it into said coil in the same direction as said main sweep current during each sweep waveform starting at a time when the main sweep current tends to become substantially non-linear such that the total current through said coil during each complete sweep rises substantially linearly, further including means for generating retrace pulses, means for initiating the operation of said ramp current generating means responsive to the generation of a retrace pulse, means for delaying the generation of said ramp current after the initiation of the operation of said ramp generating means for a substantial time interval after the start of each main sweep current waveform until said main sweep current waveform tends to become substantially non-linear.
Claim 2
Dependent Claim
191 words
A sweep circuit for causing a linear sweep current to flow through a deflecting coil comprising means for applying a step voltage across said coil to initiate each sweep waveform, the main sweep current which flows through the coil responsive to the application of said step voltage being non-linear toward the end of the sweep waveform as a result of resistance in the coil circuit, and means for generating a ramp current and injecting it into said coil in the same direction as said main sweep current during each sweep waveform starting at a time when the main sweep current tends to become substantially non-linear such that the total current through said coil during each complete sweep rises substantially linearly, further including means for generating retrace pulses, means for initiating the operation of said ramp current generating means responsive to the generation of a retrace pulse, means for delaying the generation of said ramp current after the initiation of the operation of said ramp generating means for a substantial time interval after the start of each main sweep current waveform until said main sweep current waveform tends to become substantially non-linear.
Claim 3
Dependent Claim
36 words
A sweep circuit in accordance with claim 1 further including inductor means connected in series with said deflecting coil, said ramp generating means being connected to the junction of said inductor means and said deflecting coil.
Claim 4
Dependent Claim
62 words
A sweep circuit in accordance with claim 1 wherein said ramp generating means includes means for synchronizing the operation thereof to the main sweep current waveform, further including means for delaying the generation of said ramp current for a substantial time interval after the start of each main sweep current waveform until said main sweep current waveform tends to become substantially non-linear.
Claim 5
Dependent Claim
37 words
A sweep circuit in accordance with claim 3 further including inductor means connected in series with said deflecting coil, said ramp current generating means being connected to the junction of said inductor means and said deflecting coil.
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) | 1977-11-11 | 1978-05-13 | 1978-11-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-11 | 1982-05-13 | 1982-11-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-11 | 1986-05-13 | 1986-11-12 | $7700.00 | Window Closed / Lapsed |