Active matrix display devices for digital video signals and method for driving such
US5852425A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 21, 1993 |
| Grant date | Dec 22, 1998 |
| Priority date | — |
| Expiry date | Jul 21, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G2310/027
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A TFT active matrix display device comprising an array of display elements (12), e.g. LC display elements, each connected to the drain of a TFT (17) whose gate and source are connected respectively to a row conductor (18) to which selection signals are applied by a scan drive circuit (21) and a column conductor (19) to which display data signals are applied by a data signal drive circuit (25) in the form of time dependent signals comprising pulse width modulated signals derived from an input digital video signal and representing video sample values. During the selection period the TFTs are biased to act as current sources such that their associated display elements (12) are charged to a level dependent on the duration of the applied signals. The digital to analogue conversion of the video signal is thus completed at the picture elements. In an initial part of the selection period a reference potential, which alternates between two levels in successive fields, is applied to the column conductors to reset the display elements to a predetermined level.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.