A crystal based fringe generator system

摘要

A measurement system 10 for accurately measuring the surface geometry of a part 32 in three dimensions includes a laser 12 for emitting a laser beam 14. The laser beam 14 is transmitted to a birefringent crystal 16 which splits the laser beam 14 into a pair of beams 18,20. The pair of beams 18,20 are then subjected to a phase shift by a liquid crystal system 24 as controlled by a computer 26. The pair of beams 18,20are then expended in order to form a fringe pattern 30 on the surface of the part 32 to be measured. <IMAGE>