Method and apparatus for generating bias voltages for liquid crystal display drivers
US6225992A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 5, 1997 |
| Grant date | May 1, 2001 |
| Priority date | — |
| Expiry date | Dec 5, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G2320/066
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
An apparatus and method is provided for generating a set of bias voltages for a liquid crystal display (LCD) driver to drive an LCD panel. This apparatus and method are directed to solving the problems of excessive use of I/O pads and power consumption in conventional LCD drivers and also the problems of the non-matching between externally connected resistors and the internal resistance in conventional LCD drivers. Further, externally connected capacitors for increasing bias current in conventional LCD drivers are not needed. The apparatus and method is capable of switching a bias current to a top level which causes a voltage divider to provide adequate bias voltages to the LCD driver at each instant when the LCD waveforms are being switched from one state to another, and to a bottom level when the LCD waveforms are at steady states so as to reduce power consumption to save energy.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.