Television receiver for terrestrial broadcasting
US5398080A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 3, 1993 |
| Grant date | Mar 14, 1995 |
| Priority date | — |
| Expiry date | Jun 3, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03D7/18
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In a television receiver in which image frequency signals for desired signals are removed when television broadcasting signals are frequency-converted through a local oscillator and mixers, the local oscillator generates biaxial orthogonal signals to be frequency-converted by respective mixers, an output signal of one mixer being phase-shifted to be added to an output signal of the other mixer so as to thereby offset only the image frequency signals. The local oscillator and a phase shifter operate so as to follow the frequency change of the intermediate frequency signal so as to thereby stabilize the suppression of the image frequency signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.