Integrated circuit for driving liquid crystal display using multi-level D/A converter
US5572211A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 18, 1994 |
| Grant date | Nov 5, 1996 |
| Priority date | — |
| Expiry date | Jan 18, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G2310/027
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An integrated circuit is provided for generating analog output voltages for a series of column driver output circuits used to drive an active or passive matrix LCD display. The digital value corresponding to the shade of gray for each column is stored on the integrated circuit. A shift register is clocked to sequentially enable tap points of a resistive divider network for providing four monotonically increasing analog voltages on each shift register clock cycle. A binary counter is clocked along with the shift register, and the more significant bits of the stored digital value for each column driver output circuit are each compared with the current binary count to detect a correlation. Upon detecting a correlation, the two least significant bits of the stored digital value for each column driver circuit are used to select one of the four analog voltages during the current counter cycle, and the selected analog value is sampled and held for driving a column of the LCD display.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.