(info provided thanks to me_wwwing of the Yahoo MVIS private members forum)

Laser projection source with birefringent wedge for speckle reduction

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).

http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=2&f=G&l=50&co1=AND&d=PTXT&s1=microvision&s2=laser&OS=microvision+AND+laser&RS=microvision+AND+laser

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