Active polarization switch for speckle reduction in laser projection sources
US8567957B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 11, 2011 |
| Grant date | Oct 29, 2013 |
| Priority date | — |
| Expiry date | Jun 14, 2032 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/3167
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A laser-based imaging system (200) is configured to reduce perceived speckle in images (201). The imaging system (200) includes one or more laser sources (207), a light modulator (204) configured to produce the images (201) with light (205) from the laser sources (207), and one or more active polarization switches (206) disposed in an optical path of the imaging system (200). The active polarization switch (206) is configured to alternate a polarization orientation of the light in synchrony with an image refresh cycle of the system. The active polarization switch can be clocked in accordance with a clocking angle to optimize speckle reduction. Additionally, one or more light preconditioners (991,992) may be used to help optimize speckle reduction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.