Patent · US Expired

Method and device for eliminating image speckles in scanning laser image projection

US6367935B1 · kind B1 · utility

26Cited by

7References

14Claims

0Family size

Assignee

EADS Deutschland GmbH · DE

Inventors

Lingli Wang · Chengdu, CN
Theo Tschudi · Darmstadt, DE
Thorsteinn Halldorsson · Munich, DE
Palmi Petursson · Grevesmühlen, DE

Key dates

Filing date	Oct 12, 1999
Grant date	Apr 9, 2002
Priority date	—
Expiry date	Oct 12, 2019

Classification

Technology area (CPC G)Physics
CPC primaryG03H2240/11
WIPO fieldOptics
WIPO sectorInstruments

Abstract

A method for the elimination of image speckles in a scanning laser projection is suggested, in which a phase hologram is used for dividing the illumination beam of the projector into partial beams. The partial beams are heterodyned again on the image screen within the image element (pixels) to be projected in such a way that differing speckle patterns are formed which average each other out in the eye of the viewer over time and/or space. Thus, a device is provided especially for the laser projection which substantially eliminates or reduces the speckles at the viewer. However, the beam form and the beam density are hardly or not changed.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.