Display device and driving method to control frequency of PWM signal
US9019194B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 30, 2011 |
| Grant date | Apr 28, 2015 |
| Priority date | — |
| Expiry date | Jan 14, 2033 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G2320/064
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A liquid crystal display includes a liquid crystal display panel displaying modulated data based on a frame frequency, light sources generating light to be irradiated into the liquid crystal display panel, a scanning backlight controller calculating a turn-on duty ratio of a pulse width modulation (PWM) signal for controlling turn-on and turn-off operations of the light sources, and a light source driver. The light source driver synchronizes a frequency of the PWM signal with the frame frequency or with a frequency, that is faster than two times the frame frequency, based on the result of a comparison between the turn-on duty ratio of the PWM signal and a previously determined critical value, and then sequentially drives the light sources along a data scanning direction of the liquid crystal display panel.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.