Method and apparatus for introducing a pan and scan feature to high definition television systems
US4943856A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 23, 1989 |
| Grant date | Jul 24, 1990 |
| Priority date | — |
| Expiry date | Mar 23, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N11/26
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for introducing a pan and scan feature to a multiple-signal high definition television (HDTV) system, so that a compatible signal received by a standard TV receiver may be a panned version of a wide aspect ratio HDTV signal, and so that high quality recombination of the compatible and augmenting signals by an HDTV receiver is possible. A pan and scan data word representing the relative movement of the compatible portion of the HDTV signal is inserted during the vertical blanking period of each frame of the HDTV signal, for causing panning synchronization between an HDTV transmitter and an HDTV receiver. The pan and scan data word corresponds to the beginning read address of a fixed coefficient memory containing video attenuation coefficients, which determine the degree of signal attenuation, to be applied at each pixel location along an HDTV scan line. The coefficient memory is addressed in a wrap-around manner, so that if the starting address in the read cycle is other than zero, the reading continues until the highest address in the memory is reached, and then address zero et seq. are read on up to the address before the starting address. By changing the po…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.