Contrast adjusting circuitry and video display apparatus using same
US7227543B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 27, 2005 |
| Grant date | Jun 5, 2007 |
| Priority date | — |
| Expiry date | Oct 27, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N5/70
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
With the aim of offering a video display technique by which stable and high contrast video images are reproduced, contrast adjusting circuitry is constructed. The contrast adjusting circuitry detects a maximum picture level (MPL) and an average picture level (APL) of analog-to-digital converted luminance signals for a predetermined period, determines one of the predefined luminance regions within which the MPL falls and one of the predefined luminance regions within which the APL falls, and, based on the thus determined luminance regions of both MPL and APL, carries out a contrast adjustment of video images by changing the gain of luminance signals and color depth correction by changing the gain of color signals.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.