Multi-color primary light generation in a projection system using LEDs
US7766490B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Dec 13, 2006 |
| Grant date | Aug 3, 2010 |
| Priority date | — |
| Expiry date | Jun 2, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/315
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Amber light LEDs have a higher luminance than red light LEDs. A vast majority of images displayed on television consists of colors that can be created using amber, green and blue components, with only a small percentage of red. In one embodiment of the present invention, the typically red primary light source in a projection display system is augmented with an amber light source. Green and blue primary light sources are also provided. All the light sources are high power LEDs. The particular mixture of the red and amber light is accomplished by varying the duty cycles of the red LEDs and the amber LEDs. If the RGB image to be displayed can be created using a higher percentage of amber light and a lower percentage of red light, the duty cycle of the amber LEDs is increased while the duty cycle of the red LEDs is decreased. Light/pixel modulators for creating the full color image from the three primary light sources are controlled to compensate for the variable amber/red mixture. This technique improves the efficiency of the projection system and generates less heat. A further increase in luminance can be achieved by controlling the light mixture from green and cyan LEDs as a primary…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.