Carrier wave recovery circuit
US4415933A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 15, 1980 |
| Grant date | Nov 15, 1983 |
| Priority date | — |
| Expiry date | Dec 15, 2000 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/327
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A carrier signal recovery circuit to be used in a receiving side of an image information transmitting apparatus, such as in a facsimile system, including an N-bit counter for counting reference clock pulses for a period corresponding to 2.sup.L (L being an integer) cycle periods of the received carrier signal. A first latch holds the most significant bits from the count of the N-bit counter while a second latch holds the least significant bits from the count of the N-bit counter. A frequency divider has a frequency dividing ratio corresponding to one cycle period of the carrier signal with the value of the frequency dividing ratio being initially set by the output of the first latch circuit. An auxiliary counter receiving an input from the second latch provides an output to the frequency divider for correcting the frequency dividing ratio such that the recovered carrier signal is outputted from the frequency divider.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.