Modulation of line-select times of individual rows of a flat-panel display for gray-scaling
US6057809A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 20, 1998 |
| Grant date | May 2, 2000 |
| Priority date | — |
| Expiry date | May 20, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G2330/06
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The amount of time that a row of pixels in a flat-panel display is illuminated is modulated from frame-to-frame and from row-to-row. Pixels in rows that are on for a longer period of time appear brighter than pixels in rows that are on for shorter periods of time. Such line modulation is combined with frame-rate-cycling (FRC) to dramatically increase the number of gray scales that can be generated for any given number of frames in a FRC cycle, and with phase-offsetting to keep the frame period constant and to reduce flicker. An N-frame FRC cycle that previously generated N+1 gray scales now produces a full 2.sup.N gray scales. The total pixel-on time over the N frame cycle depends not just on how many frames the pixel is on, but on which frames the pixel is on. Since each row in each frame in the FRC cycle is on for a different amount of time, aliasing of the frames is greatly lessened or no longer occurs. A line modulation buffer and speeding up the pixel clock to the panel allow for greater modulation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.