Method and apparatus for real-time on-off contrast ratio optimization in liquid crystal displays
US6333728A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 3, 1998 |
| Grant date | Dec 25, 2001 |
| Priority date | — |
| Expiry date | Sep 3, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G2320/041
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An apparatus provides optimal on-off contrast ratio in a liquid crystal display panel. The apparatus includes a capacitive temperature sensing device for sensing the temperature of liquid crystal display pixels and having an output voltage according to an applied input voltage and a sensed temperature; PA1 a monitoring device including differentiator and sample and hold circuit for obtaining a peak voltage corresponding to a maximum change of the voltage output from the temperature sensing device; and a device for measuring a difference between the peak voltage with a predetermined reference voltage and outputting a signal representing the difference. Heat is consequently applied to the liquid crystal display panel in accordance with a measured temperature difference. Advantageously, the capacitive temperature sensing device is formed as part of the liquid crystal display element.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.