Output stabilization for a laser matrix
AssigneeKoninklijke Philips Electronics N.V.
InventorsPeter Ferdinand Greve, Olaf Thomas Johan Antonie Vermeulen
Life of this patent
Estimating the term…
Loading patent…
AssigneeKoninklijke Philips Electronics N.V.
InventorsPeter Ferdinand Greve, Olaf Thomas Johan Antonie Vermeulen
Estimating the term…
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.
A projection device comprising a matrix of semiconductor lasers, an optical system for imaging the matrix on an element illuminated by the projection device, a control device for controlling the semiconductor lasers, which control device comprises a feedback device including a first detector for detecting the intensity of a light spot projected by each semiconductor laser on the illuminated element via the optical system, and for generating a first signal representing the detected intensity, wherein the control device is adapted to control the semiconductor lasers one by one in a first adjusting phase and in a second adjusting phase, in that the control device is adapted to adjust the intensity of the light spot on the basis of the first signal in the first adjusting phase relating to a controlled semiconductor laser, in that the feedback device is adapted to detect, in the first adjusting phase, light emitted by the controlled semiconductor laser and not originating from the light spot, and to generate a second signal representing the detected light, in that the feedback device comprises a memory for storing, in the first adjusting phase, the second signal generated in relation to the controlled semiconductor laser, and in that the control device is adapted to control, in the second adjusting phase, a controlled semiconductor laser on the basis of the second signal generated in relation to the controlled semiconductor laser, such that the second signal generated in the second adjusting phase in relation to the controlled semiconductor laser substantially corresponds to the second signal stored in the memory in the first adjusting phase relating to the controlled semiconductor laser, wherein the first adjusting phase is during an imaging interval of time and the second adjusting phase is during a non-imaging interval of time.
A method of adjusting a projection device comprising a matrix of semiconductor lasers, the method comprising the acts of:
Dependencies are inferred from the claim text.