Speckle reducer and projection unit including a speckle reducer
US8833945B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Apr 27, 2011 |
| Grant date | Sep 16, 2014 |
| Priority date | — |
| Expiry date | Nov 9, 2031 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F1/0147
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The present speckle reduction device comprises an optical element intended to be passed through by the coherent light beam to be treated. It also includes means able to cause heating of the said optical element; and a cooling element coupled to the said optical element so as to be able to cool the latter. A control module is configured to control the heating means and the cooling element so as to create thermal perturbations in the optical element, causing corresponding variations in the refractive index of the said optical element. The optical element is a piezoelectric crystal which is excited in a specific deformation mode causing its heating.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.