Digital time base corrector oscillators
US3971063A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 13, 1975 |
| Grant date | Jul 20, 1976 |
| Priority date | — |
| Expiry date | Mar 13, 1995 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/896
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The television digital time base corrector for television equipment comprises an analogue to digital converter for receiving a video analogue signal, a store for receiving the successive line information in digital form from the output of the analogue to digital converter, a digital to analogue converter for receiving the stored signal, a read/write control circuit for writing the digital information into the store, an input oscillator for determining the rate of conversion of the analogue signal and the rate of writing into the store and output oscillator for controlling the rate of reading out of the digital information from the store and the rate of conversion of the digital information in the store. The input oscillator is in the form of a triggered oscillator which is switched on and off in time relationship with the video sync pulse and/or sub-carrier color burst, the period of switching on and off and the frequency of the oscillator being dependent upon the duration of the lines. Thus the length of the train of sampling clock pulses is varied in sympathy with the off-tape line period by changing the frequency of the clock pulses from line to line.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.