| 摘要 |
PURPOSE:To execute recording and reproducing to and from every optical recording medium different in characteristic by detecting a reflected light of a light projected onto an optical recording medium, rotating a polarizing plate in an optical path by its output, and making a passing light quantity optimum in accordance with optical recording mediums whose recording sensitivity is different each other. CONSTITUTION:A reflected light of a light projected to an optical recording medium 2 is photodetected by a photodetector 4, its output is compared with reference voltage by a comparator 23, and a signal corresponding to its magnitude is inputted to a decoder 24. When recording or reproducing is selected by an operating button, a switch 21 is turned on, and a signal corresponding to it is inputted to the decoder 24 from an NAND gate 22. As for an output from the decoder 24, there are four kinds of signals with respect to recording or reproducing of the optical recording medium whose erasion is possible or impossible, but in accordance with each of them, a polarizing plate 20 is rotated through a motor controlling circuit 25 and a stepping motor 26, it is controlled so that a transmission light quantity of a light from a light source 13 becomes optimum, and recording and reproducing are executed. |
