Liquid crystal display device, device for controlling drive of liquid crystal display device and D/A converting semiconductor device
US6191779A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 13, 1998 |
| Grant date | Feb 20, 2001 |
| Priority date | — |
| Expiry date | Jul 13, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G2330/023
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A liquid crystal display device significantly reduces power consumption and causes no signal delay when a liquid crystal panel performs an inversion-type drive. The liquid crystal display device comprises a digital controller, a level shift circuit, a digital-to-analog (D/A) converter, a liquid crystal panel, and a plurality of capacitors. In the D/A converter, a charging control circuit is provided corresponding to each capacitor. The charging control circuit comprises a switch, a diode and an inverter, the switch and the diode being coupled in parallel. The switch is turned on and off in response to a switching signal from the digital controller. The switch is changed to a turning- on state during a blanking period after one horizontal displaying. Upon turning-on of the switch, the capacitors are charged. Digital pixel data outputted from the digital controller undergoes a level changing depending on a voltage across the electrodes of the capacitors, according to a charge conservation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.