OPTICAL REVERSIBLE RECORDING AND REPRODUCING DEVICE

摘要

PURPOSE:To improve the weather resistance of an optical disc and to make the quality of recording identical by irradiating an erasure spot light onto a disc at both simultaneous erasure and recording of a non-recording track so as to use the identical thermal recording condition. CONSTITUTION:An output light of wavelength lambda1 of a semiconductor laser 6 is made to a parallel optical beam by a condenser lens 7, made incident on an aperture lens 11 through an optical element of an optical beam combiner 8 or the like so as to form a circular optical spot L on a guide track 1. On the other hand, an output light of wavelength lambda2 of a semiconductor laser 13 is formed by bringing an elliptic optical spot M whose major diameter is coincident with the lengthwise direction of the track 1 close to the spot L. The spot L is used for recording and reproducing the signal and the spot M gives a temperature rise gradual cooling condition to the optical disc, so as to attain crystal state.