System and method for improving the multiplexing capability of a liquid crystal display and providing temperature compensation therefor
US4462027A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 15, 1980 |
| Grant date | Jul 24, 1984 |
| Priority date | — |
| Expiry date | Feb 15, 2000 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G2320/041
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A system and method for controlling the effective root mean square (RMS) voltage (Veff) across the segments of a liquid crystal display as a function of the frequency of the voltage signal applied thereto and selected parameters of the display package are described. Display parameters such as the thickness of the barrier dielectric layer and the electrical resistance of the liquid crystal material are chosen so that the ON and OFF states of the display are selectively controllable by lowering the frequency of the drive voltage signal applied to the OFF segments (Foff) a predetermined amount below that of the drive voltage signal applied to the ON segments (Fon), thereby decreasing the ratio of the effective RMS voltage Veff to the RMS voltage of the applied voltage signal (Vapp) for the OFF segments as compared to the ratio Veff/Vapp for the ON segments. The number of drive lines which can be effectively multiplexed is thereby increased. By proper selection of drive frequencies and other display parameters, temperature compensation without the need for additional sensors and circuitry is also achieved.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.