Television receiver with perceived contrast reduction in a predetermined area of a picture where text is superimposed
US5418576A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 19, 1994 |
| Grant date | May 23, 1995 |
| Priority date | — |
| Expiry date | Sep 19, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N5/44504
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The television receiver includes a text generation mechanism which is capable of superimposing text on a received picture. In order to make the text more legible, while still retaining picture information a reduced contrast area is formed around the text. In order to superimpose the text on the picture text, RGB signals are applied to the video output circuits together with a switching signal (VDS) which causes either text or picture signals to be applied to the display device. To provide a reduced contrast area around the text display the switching signal (VDS) is arranged to switch between the picture signal and blanking level at a fast rate, for example at the clock rate, to produce the reduced contrast area.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.