Flat panel display screen with programmable gamma functionality
US6359389B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 9, 2000 |
| Grant date | Mar 19, 2002 |
| Priority date | — |
| Expiry date | Jun 9, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G2320/0673
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A flat panel display having a programmable gamma without incidental loss in gray scale resolution. In one embodiment, the flat panel display is a liquid crystal display (LCD). The invention includes applying and adjusting a set of gamma controlling voltages to the DC reference circuit (a.k.a. ladder voltages) of an LCD module producing a change in the gamma response (or profile) of the LCD module without incidental loss of gray scale resolution. An adjustable ladder circuit (ALC) is thereby realized. Separate ALCs can be provided for red, green and blue primaries. By adjusting, in a predetermined fashion, the reference voltages applied to the row and column drivers of an LCD display, the gamma response of the LCD can be changed to a different value. Because the input digital signals are not affected, the same color resolution and dynamic range are maintained. The DC reference circuit can be a multi-node voltage divider. These voltage nodes are applied to the row and column drivers of the LCD module to control the ON/OFF states of each red, green and blue sub-pixel. The input digital signals provided by the host's graphic source or software application modulate these voltage nodes t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.