US4919640A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Auto tuning apparatus
Assignee: Sony Corp
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Filing: 1988-09-21
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Granted: 1990-04-24
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Expires: 2008-09-21
Abstract
Abstract An auto tuning apparatus sequentially varies the value of N, a positive integer, in the frequency-dividing ratio 1/N of a variable frequency-dividing circuit incorporated in a local oscillating circuit having a phase locked loop configuration. The apparatus detects a plurality of candidate tuning points of an intermediate frequency carrier and includes a circuit for performing a scan of those tuning points by, among other steps, changing a tuning point detecting threshold relative to the level of the received signal. A circuit is provided for determining the correct or optimum tuning point on the basis of the scan.
Inventors
- 👤 Masami Yanagibori
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 21:27
CPC Classifications
H; H03; H03J; H03J7/00; H03J7/18; H03J1/00; H03J1/0008; H03J1/0041; H03J1/005
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
163 words
Auto tuning apparatus for automatically determining a correct tuning point of an intermediate frequency carrier of a received signal, said apparatus comprising: a local oscillating circuit for adjusting the IF carrier of the received signal having a phase locked loop configuration and including a variable frequency-dividing circuit having a frequency dividing ratio l/N, where N is a positive integer, and means for sequentially varying the value of N; detecting means for detecting a plurality of tuning points of said intermediate frequency carrier; scanning means responsive to said detecting means for carrying out a scan of said plurality of tuning points by varying a tuning detecting threshold value relative to a level of said received signal; means responsive to said scanning means for determining said correct tuning points and causing the sequential variance of N; and sensitivity adjusting means responsive to said detecting means for adjusting the signal level of said received signal when a number of said plurality of tuning points is detected.
Claim 2
Dependent Claim
163 words
Auto tuning apparatus for automatically determining a correct tuning point of an intermediate frequency carrier of a received signal, said apparatus comprising: a local oscillating circuit for adjusting the IF carrier of the received signal having a phase locked loop configuration and including a variable frequency-dividing circuit having a frequency dividing ratio l/N, where N is a positive integer, and means for sequentially varying the value of N; detecting means for detecting a plurality of tuning points of said intermediate frequency carrier; scanning means responsive to said detecting means for carrying out a scan of said plurality of tuning points by varying a tuning detecting threshold value relative to a level of said received signal; means responsive to said scanning means for determining said correct tuning points and causing the sequential variance of N; and sensitivity adjusting means responsive to said detecting means for adjusting the signal level of said received signal when a number of said plurality of tuning points is detected.
Claim 3
Dependent Claim
24 words
Auto tuning apparatus according to claim 1, further comprising a read only memory for supplying successive values of N to said variable frequency-dividing circuit.
Claim 4
Dependent Claim
43 words
Auto tuning apparatus according to claim 1, wherein said local oscillating circuit further includes a voltage controlled oscillator and pre-scaler responsive to said voltage-controlled oscillator for dividing an output thereof by a constant to generate a signal for division by said variable divider.
Claim 5
Dependent Claim
152 words
Auto tuning apparatus for automatically determining a correct tuning point of an intermediate frequency carrier of a received signal, said apparatus comprising: a local oscillating circuit for adjusting the IF carrier of the received signal having a phase locked loop configuration and including a variable frequency-dividing circuit having a frequency dividing ratio l/N, where N is a positive integer, and means for sequentially varying the value of N; detecting means for detecting a plurality of tuning points of said intermediate frequency carrier; scanning means responsive to said detecting means for carrying out a scan of said plurality of tuning points; sensitivity adjusting means connected to said detecting means for adjusting the level of the received signal in response to the detection of the plurality of tuning points; and means responsive to said scanning means and said sensitivity adjusting means for determining said correct tuning point and causing the sequential variance of N.
Claim 6
Dependent Claim
152 words
Auto tuning apparatus for automatically determining a correct tuning point of an intermediate frequency carrier of a received signal, said apparatus comprising: a local oscillating circuit for adjusting the IF carrier of the received signal having a phase locked loop configuration and including a variable frequency-dividing circuit having a frequency dividing ratio l/N, where N is a positive integer, and means for sequentially varying the value of N; detecting means for detecting a plurality of tuning points of said intermediate frequency carrier; scanning means responsive to said detecting means for carrying out a scan of said plurality of tuning points; sensitivity adjusting means connected to said detecting means for adjusting the level of the received signal in response to the detection of the plurality of tuning points; and means responsive to said scanning means and said sensitivity adjusting means for determining said correct tuning point and causing the sequential variance of N.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-04-23 | 1993-10-23 | 1994-04-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-04-23 | 1997-10-23 | 1998-04-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-04-23 | 2001-10-23 | 2002-04-24 | $7700.00 | Window Closed / Lapsed |