Automatic continuous tuning control apparatus for a receiver
US4476580A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Jun 10, 1981 |
| Grant date | Oct 9, 1984 |
| Priority date | — |
| Expiry date | Jun 10, 2001 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03J5/0281
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A tuning control apparatus of a receiver having an electronic tuner comprises a tuning voltage generating circuit including a window comparator, a charge pump and a low-pass filter. An S curve signal is applied to the window comparator to make a search controlled by means of a voltage synthesizer system using the S curve signal until the receipt of a broadcasting signal. If an optimum tuning point is established through the search control, the local oscillation frequency at that time is counted to provide frequency division ratio data. A phase-locked loop is operated as a function of the frequency division ratio data on the occasion of the above described optimum tuning point, whereby reception of the broadcasting signal is continued. Preferably, an automatic frequency control operation is performed before the phase-locked loop is operated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.