Signal defect compensation
US4021852A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 21, 1975 |
| Grant date | May 3, 1977 |
| Priority date | — |
| Expiry date | Aug 21, 1995 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/882
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A system is provided for compensating for signal defects such as dropouts in recorded television signals. A recovered video signal is delayed for a period of substantially one scanning line, and the delayed signal is coupled to two channels, one for the luminance and scan synchronizing information and the other for the color information. The color information is phase-reversed each time it is delayed so as to provide a proper phase relationship when reinserting the delayed information into the signal path. The two channels are recombined to provide a compensating signal which is substituted for the original video signal during a dropout. In addition, when a head-switching transient such as occurs in a quadruplex VTR is sensed, a further mode of operation is activated in which the system substitutes a portion of the prior line horizontal blanking interval for the duration of the switching transient so as to prevent degradation of the synchronizing signal and resultant disturbance to the operation of the recorder servo systems.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.