Output stabilization for a laser matrix

摘要

A projection device comprises a matrix ( 1 ) of semiconductor lasers, an optical system ( 2 ) for projecting the matrix ( 1 ) on an element ( 3 ) illuminated by the projection device, and a control device ( 9 ) for controlling the semiconductor lasers through a feedback device. The feedback device comprises a first detector ( 13, 14 ) that generates a first signal representing the detected intensity. The semiconductor lasers are controlled and the intensity of the light spot is adjusted to a desired value by the feedback device. Light from a semiconductor laser is detected by a second detector ( 18 ), and a value of the detected signal is stored in an addressable memory cell. The amount of emitted light is stabilized for each semiconductor laser by detection through the second detector ( 18 ) and comparison with the value stored in the memory ( 29 ) for the relevant controlled semiconductor laser.