OPTICAL RECORDING AND REPRODUCING METHOD

摘要

PURPOSE:To attain the recording and reproduction which permits miniaturization and low cost of the device by using a member whose optical characteristic is changed due to temperature rise by light radiation, increasing the output of a semiconductor laser at recording. While decreasing the output at the reproduction than at recording. CONSTITUTION:A laser light radiated from a semiconductor laser 1 is focused by lenses 2, 2' into a spot of nearly lmum and radiated onto a recording face of a disk 3. The optical characteristic of the disk 3 is changed because it absorbs the heat of the laser right and the temperature rises, and a contract signal is written on a recording face of the disk 3 by the laser light. In case of the reproduction, a slightly weaker light is radiated onto the recording face and the light beam having a light-and-shade signal is extracted as a reflected light. The reflected light is bent by a half mirror 4 and the signal is detected by a photodetector 5. The optical recording/reproduction is executed by using a single semiconductor laser in this way and the miniaturization and low-cost are attained for the optical recording/reproducing system.