A READING/WRITING OPTICAL DEVICE HAVING TEMPERATURE COMPENSATION

摘要

An optical data reading/writing device for reading/writing to an information layer, the device comprising at least a first radiation source (12) for generating a radiation beam and an optical system (10, 40, 44, 46, 48, 50, 52, 54, 56) for converging the radiation beam on the information layer and for converging the radiation beam reflected by the information layer onto a detector, wherein the optical system incorporates a wavelength sensitive structure which compensates for a temperature-induced defocusing of the optical system.