Liquid crystal display device
US7106294B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 25, 2003 |
| Grant date | Sep 12, 2006 |
| Priority date | — |
| Expiry date | Jan 11, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G2320/064
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A doubler part doubles frequencies of video signals. A drive control circuit generates, in response to a synchronizing signal outputted from the doubler part, PWM dimming frequency information such that a PWM dimming frequency f and a black display ratio B satisfy the relationships f≧25B+250 and B>10, and provides such information to a PWM dimming signal generation circuit. In addition, the drive control circuit drives a gate driver and a source driver such that one frame period is divided into an image display period and a black display period. The PWM dimming signal generation circuit generates, in response to a synchronizing signal and the PWM dimming frequency information, a PWM dimming signal and provides the PWM dimming signal to a lighting circuit. The lighting circuit activates a backlight device with dimming, in response to the PWM dimming signal. This configuration reduces colored interference fringes in a liquid crystal display device resulting from the combination of a black insertion drive technique and a PWM dimming technique.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.