Drive signal generator and image display apparatus
US6882329B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Sep 27, 2002 |
| Grant date | Apr 19, 2005 |
| Priority date | — |
| Expiry date | Aug 22, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G2310/027
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A drive signal generation circuit which performs gradation control on a load by a drive signal having a stepped waveform. In a case where the wave height value corresponding to input gradation data is Vm (2≦m≦n), the drive signal is caused to rise in such a manner that each output Vk (2≦k≦m) is produced one slot after the output V(k−1) to increase the wave height value V0 (reference potential) to Vm in a stepping manner. One slot corresponds to a unit time of the pulse width modulation. The drive signal is caused to fall in such a manner that each output V(k−1) (1≦k≦m−1) is produced one or two slots after the output Vk to reduce the wave height value from Vm to off level in a stepping manner. A delay circuit is used to delay signals slot by slot. A selection is made from delayed signals according to luminance data to determine a waveform. The circuit is also designed to enable the drive signal waveform rise position to be changed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.