Laser projection source with birefringent wedge for speckle reduction
US8049825B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 16, 2009 |
| Grant date | Nov 1, 2011 |
| Priority date | — |
| Expiry date | Apr 9, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/3129
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An imaging system (200), such as a scanned laser projection system, includes one or more laser sources (201) configured to produce one or more light beams (204), and a light modulator (203) configured to produce images (206) from the light beams (204). Optional optical alignment devices (220) can be used to orient the light beams (204) into a combined light beam (205). A birefringent wedge (221) is disposed between at least one of the laser sources (201) and the light modulator (203). The birefringent wedge (221) is configured to receive light from the laser sources (201) and deliver two angularly separated and orthogonally polarized light beams (223) to the light modulator (203) so as to reduce speckle appearing when the images (206) are displayed on a display surface (207). An optional glass wedge (1004) can be used to correct optical path deviation (1001) introduced by the birefringent wedge (221).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.