Color wheel synchronization apparatus and method
US5967636A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 19, 1998 |
| Grant date | Oct 19, 1999 |
| Priority date | — |
| Expiry date | Aug 19, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/3129
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A multimedia projector (30) employing a color wheel (42) in a frame sequential color display system includes a light sensor (68) positioned to receive light scattered from a point in an optical path (34) after the color wheel. The light sensor detects particular colors of light propagating through red, green, and blue filter segments (R, G, and B) on the color wheel and toward a display device (50). The light sensor provides, without any adjustments, an inherently accurate timing mark signal (78) to a display controller (56) to ensure that red, green, and blue image data are properly synchronized with the respective filter segments R, G, and B. In particular, the light sensor receives polychromatic light through a yellow optical filter (74) to illuminate an optoelectric detector (70) that is responsive to visible and near IR light wavelengths. The photodetector drives a timing mark signal generator (80) to detect a sudden increase in yellow (red plus green) light, which indicates to the display controller that filter segment R has just rotated into the optical path.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.