Modulated-amplitude illumination for spatial light modulator
US6232963A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 14, 1998 |
| Grant date | May 15, 2001 |
| Priority date | — |
| Expiry date | Sep 14, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G2320/064
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Methods of controlling the illumination source (18) of an SLM-based display system (10). It is assumed that the system (10) displays pixel data formatted into a bit-plane format so that all bits of the same bit-weight can be displayed simultaneously. To provide greyscale, the amplitude of the source (18) may be modulated so that bit-planes having greater bit-weights are displayed with more intense illumination than bit-planes having smaller bit-weights (FIGS. 2 and 3). To avoid visual artifacts, the duty cycle of the bit-plane display times may be shortened relative to the frame period. (FIG. 4A). The latter method can be accompanied by a shortening of the duty time of the illumination on SLM (15). (FIG. 4B). The short duty cycle method may be used together with illumination amplitude modulation, or it may be used with the PWM method of providing greyscale.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.