Liquid crystal drive circuit and liquid crystal display system
US6281890A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 17, 1998 |
| Grant date | Aug 28, 2001 |
| Priority date | — |
| Expiry date | Jun 17, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G3/3696
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A liquid crystal panel is turned on upon power ON, and wastes electric power. A liquid crystal drive circuit of this invention has a shift register (111) for receiving an input signal IN and a clock CLK, and shifting the signal IN, an output selection circuit (112) for receiving a shifted signal Q1 and a frame signal FR, and outputting signals SEL1 to SEL4, an output buffer (113) for receiving the signals SEL1 to SEL4 and voltages V1 to V4, and outputting one of these voltages, a selection control circuit (21) for receiving signals Q157 to Q160 output from shift register units in four continuous blocks from the final stage, and for determining abnormal operation and outputting signals S1 and /S1 when all the input signals are at a predetermined level, and a clock control circuit (12) for inputting a given signal to the shift register unit (111) upon reception of the signals S1 and /S1 so as to make the shift register unit (111) operate as an inverter array. Usually, upon power ON, the internal signals assume unknown values, and the liquid crystal panel wastes electric power if it is turned on in such state. When the liquid crystal panel is set in a non-display state by the above ar…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.