Video signal processing circuit providing optimum signal level for inverse gamma correction
US6271891A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 18, 1999 |
| Grant date | Aug 7, 2001 |
| Priority date | — |
| Expiry date | Jun 18, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G2320/0271
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A video signal processing circuit in which nearly 100% of a largest possible dynamic range can be used, desired contrast is obtained, and desired brightness characteristics are obtained by an increasing in luminance of a screen. The circuit has an RGB amplifier which amplifies three primary color video signals R, G, and B by a predetermined gain and in which the gain is controlled by a gain control signal, A/D converters for converting analog three primary color video signals which are generated from the RGB amplifier into digital signals respectively, inverse gamma correcting circuits for effecting an inverse gamma correction to the three primary color digital video signals respectively, an OR circuit and a peak holding circuit for detecting peak levels of the analog three primary color signals, and a gain control signal generator for generating a gain control signal in accordance with the peak levels. When the peak levels are equal to or larger than a predetermined value, the gain control signal generator supplies the gain control signal to control the RGB amplifier so as to set the level of each of the three primary color digital video signals generated by the A/D converters at …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.