US3737787A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electronic signal seeking system with rapid scan
Assignee: RCA Licensing Corp
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Filing: 1971-06-29
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Granted: 1973-06-05
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Expires: 1991-06-29
Abstract
Abstract A signal-seeking tuning control system for use with a voltagecontrolled tuner. A ramp generator is operated manually to cause the tuner to sweep through a spectrum of channel frequencies. When the converted-frequency signal outputted by the tuner approaches a desired frequency range a discriminator produces an error signal for energizing a control system having three discrete states. when the discriminator output is within a fixed, narrowly defined range the control system arrests the operation of the ramp generator. Should the converted frequency drift beyond the narrow range, the discriminator produces an error signal which reflects the change in frequency, energizing an appropriate segment of the control to operate the ramp generator. Retrace means are provided for recycling the ramp generator when the voltage outputted thereby achieves a predetermined maximum or minimum value.
Inventors
- 👤 A Wolfram
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 02:25
CPC Classifications
H; H03; H03J; H03J7/00; H03J7/18; H03J7/20; H03J7/24; H03J7/26
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
183 words
In a television receiver including a voltage-controlled tuner for producing an IF signal in response to a received signal, means for operating said voltage-controlled tuner comprising: discriminator means responsive to said IF signal for producing an error indication when said IF signal deviates from a desired frequency, control means responsive to said error indication to produce a first control voltage when said IF signal is lower than said desired frequency and a second control voltage when said IF signal is higher than said desired frequency, voltage generating means applying a changing voltage to said tuner in response to said first or second control voltage to cause said tuner to lock-on to a received signal when the IF signal produced thereby corresponds to said desired frequency, and scan initiation means connected to said control means when activated to inhibit said control means from responding to said error indication and selectively causing said control means to produce one of said first and second control voltages so long as said scan initiation means is activated to cause said tuner to sweep through a spectrum of frequencies.
Claim 2
Dependent Claim
183 words
In a television receiver including a voltage-controlled tuner for producing an IF signal in response to a received signal, means for operating said voltage-controlled tuner comprising: discriminator means responsive to said IF signal for producing an error indication when said IF signal deviates from a desired frequency, control means responsive to said error indication to produce a first control voltage when said IF signal is lower than said desired frequency and a second control voltage when said IF signal is higher than said desired frequency, voltage generating means applying a changing voltage to said tuner in response to said first or second control voltage to cause said tuner to lock-on to a received signal when the IF signal produced thereby corresponds to said desired frequency, and scan initiation means connected to said control means when activated to inhibit said control means from responding to said error indication and selectively causing said control means to produce one of said first and second control voltages so long as said scan initiation means is activated to cause said tuner to sweep through a spectrum of frequencies.
Claim 3
Dependent Claim
46 words
The invention as defined in claim 1, further including means responsive to said error indication and to sync signals derived within said television receiver for enabling said control means to respond to said error indication only when a video IF carrier is produced by said tuner.
Claim 4
Dependent Claim
60 words
The invention as defined in claim 1, further including reset means responsive to said changing voltage reaching one end of its range to reset said voltage generating means to the opposite end of its range, and band switching means coupled to said reset means to change the band of frequencies scanned by said tuner when said changing voltage is reset.
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) | 1976-06-04 | 1976-12-04 | 1977-06-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-04 | 1980-12-04 | 1981-06-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-04 | 1984-12-04 | 1985-06-05 | $7700.00 | Window Closed / Lapsed |