System and method for reduced-speckle laser line generation

Abstract

A coherent beam moves across a stationary line generator, allowing the speckle pattern projected through the diffuser onto the surface—for example using a MEMS mirror, or another arrangement that is free of a moving mass, such as solid state beam deflector (e.g. an AOM). Where an image sensor is employed, such as a DS, the beam is moved at a speed of at least ½ cycle per image frame so that the full length of the line within the imaged scene is captured by the image sensor. The distance traversed on the diffuser provides sufficient uncorrelated speckle patterns within an exposure time to average to a smooth line. The MEMS mirror can be arranged to oscillate in two substantially orthogonal degrees of freedom so that the line is generated along a first direction and the line moves along the working surface in a second direction.

What is claimed is: 
     
         1 . A system for generating a line on a working surface with reduced speckle comprising:
 a laser source in the form of a collimated beam;   a line generator that receives at least part of the collimated beam and projects the light passing therethrough onto the working surface as a line; and   a moving element that causes the collimated beam to move in an oscillatory motion substantially within at least one plane.