Signal-seeking tuning system with a seaching mode activated by the user's operation of a manual band switch
US4624014A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 23, 1984 |
| Grant date | Nov 18, 1986 |
| Priority date | — |
| Expiry date | Jan 23, 2004 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03J7/18
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An automatic signal-seeking television receiver has a pair of capacitors for developing tuning voltages for the VHF and UHF bands, respectively. A manual bandswitch arrangement for selecting the frequency band of the tuner, selects one of the capacitors for developing the tuning voltage for the selected band and applies a predetermined voltage, e.g. ground, to the capacitor for the non-selected band. Thus, after bandswitching, the signal-seeking always automatically starts from a predetermined frequency, e.g. the lower frequency boundary of the selected band. A charging circuit charges or discharges the capacitor for the selected band to provide frequency sweep in accordance with the operation of one of a pair of manual tuning direction setting switches. A direction reversing circuit is used to reverse the direction of the frequency sweep if no signal is found by the time the sweep reaches a frequency boundary of a selected band and also is responsive to the predetermined voltage initially developed by the capacitor of the newly selected band after manual bandswitching to automatically start the frequency sweep.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.