US3692932A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Horizontal oscillator disabling circuit control apparatus
Assignee: RCA Licensing Corp
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Filing: 1971-05-18
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Granted: 1972-09-19
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Expires: 1991-05-18
Abstract
Abstract Concurrently filed United States Patent application Ser. No. 144,457, entitled ''''HORIZONTAL OSCILLATOR DISABLING CIRCUIT'''' describes a means of shifting the frequency of the horizontal oscillator of a television receiver in the presence of high voltage increases which could cause X-radiation problems. As therein described, a negative direct voltage indicative of the developed ultor potential for its cathode-ray tube is combined with a relatively stable positive direct voltage to change the bias on a control transistor and the effective resistance in the time constant network determining the oscillator frequency. The present invention provides a further positive direct voltage to the transistor from the brightness control network of the receiver, so as to control the point at which the oscillator goes off frequency as a function of picture tube beam current. Such further voltage will be seen to reduce the criticality in determining the point at which the frequency shifting is to occur and the point at which the reproduced picture becomes unviewable.
Inventors
- 👤 Paul Carleton Wilmarth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 04:55
CPC Classifications
H; H04; H04N; H04N3/00; H04N3/10; H04N3/16; H04N3/20
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
219 words
In a television receiver having an image display device, a deflection circuit including an oscillation signal generator, and a high voltage circuit responsive to the generation of such oscillation signals to develop the high voltage needed to operate said display device, and wherein a resistance-capacitance time constant network is also included to set the frequency at which said oscillation signals are generated and to vary such frequency in a direction to render the image reproduction of said display device unviewable in response to the development of a control signal reflecting a high voltage condition in excess of the upper limit of a prescribed operating range, the combination therewith of: first means for manually setting the beam current flow in said display device as a function of a direct voltage generated thereby and applied to a control electrode of said display device; and second means coupled to additionally receive at least a portion of said direct voltage and to alter the control signal applied to change the frequency of said oscillation signals as a function of beam current flow; whereby the protective alert provided as to the existence of high voltage problems within said receiver when the image reproduction of said display device is rendered unviewable occurs for different conditions of high voltage as said beam current is manually adjusted.
Claim 2
Dependent Claim
219 words
In a television receiver having an image display device, a deflection circuit including an oscillation signal generator, and a high voltage circuit responsive to the generation of such oscillation signals to develop the high voltage needed to operate said display device, and wherein a resistance-capacitance time constant network is also included to set the frequency at which said oscillation signals are generated and to vary such frequency in a direction to render the image reproduction of said display device unviewable in response to the development of a control signal reflecting a high voltage condition in excess of the upper limit of a prescribed operating range, the combination therewith of: first means for manually setting the beam current flow in said display device as a function of a direct voltage generated thereby and applied to a control electrode of said display device; and second means coupled to additionally receive at least a portion of said direct voltage and to alter the control signal applied to change the frequency of said oscillation signals as a function of beam current flow; whereby the protective alert provided as to the existence of high voltage problems within said receiver when the image reproduction of said display device is rendered unviewable occurs for different conditions of high voltage as said beam current is manually adjusted.
Claim 3
Dependent Claim
68 words
The combination of claim 1 wherein said second means is coupled to alter said control signal in a direction whereby said protective alert is provided for conditions of greater high voltage in excess of the upper limit of its operating range when beam current is set low, as contrasted with lesser high voltages in excess of the upper limit of its range when beam current is set high.
Claim 4
Dependent Claim
110 words
The combination of claim 2 for use in a television receiver incorporating a transistor biased to a first state of conduction for the development of high voltage within its prescribed range of operation and changed to a non-conductive condition for the development of high voltage in excess of the upper limit of its operating range, and wherein said change in transistor conduction is translated into a change in the resistance component of said time constant network determining the frequency at which said oscillation signals are generated, further characterized by said second means providing its direct voltage to alter the bias on said transistor as a function of beam current flow.
Claim 5
Dependent Claim
83 words
The combination of claim 3 for use in a television receiver wherein said transistor is biased by a first relatively stable direct source of positive potential and by a negative potential of a magnitude reflecting the development of high voltages within said receiver, additionally characterized by said second means applying a further positive potential to said transistor to delay the switching of said transistor from a saturated condition to a non-conductive condition as a function of beam current flow in said display device.
References Cited (Backward Citations)
US3611002A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-09-19 | 1976-03-20 | 1976-09-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-19 | 1980-03-20 | 1980-09-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-19 | 1984-03-20 | 1984-09-19 | $7700.00 | Window Closed / Lapsed |