Optical and reversible recording and reproducing apparatus.

摘要

This invention relates to an optical and reversible recording and reproducing apparatus and intends to provide a practical apparatus in which information signals can be recorded, reproduced and erased by irradiating a laser beam and the like on the substrate to be optically recorded. More practically, there is provided such an apparatus wherein two light sources such as lasers having different wavelengths are used, and a first almost circular micro-lightspot is produced by one light source, while a second elliptic lightspot having a longitudinal diameter in the tangential direction of a guide track on a disc is produced by the other light source. These first and second lightspots are closely irradiated on the same guid track of an optical recording disc. The recording and reproducing of the signals are performed using the first lightspot while the erasion of the recorded signals can be made by using the second lightspot or cooperatively using the first and second lightspots.