| 摘要 |
PURPOSE: To simply and rapidly decide whether or not a part intended to record information is an information unrecorded area by providing a means, etc., in which the same track is irradiated with a reproducing light beam preceding a recording light beam. CONSTITUTION: A laser light beam radiated from a light source is divided to plural light beams, that is, one main beam 12 for recording information and plural sub-beams 141, 142, 151, 152 distributed on two straight lines 131, 132 intersecting with the beam 12, and they are converged, and a recording medium 9 is irradiated by them. Reflected light beams of the main beam 12 and plural sub-beams 141, 142 from the recording medium are received by a light receiving element unit 17 consisting of plural light receiving elements 17a-h, and focusing and tracking are performed by the main beam 12 and the sub-beams 141, 142 distributed on the one side straight line 131. Further, a decision of whether or not the part is the information unrecorded area and the confirmation of whether or not the information is recorded correctly are performed by two sub-beams 151, 152 distributed on the other straight line 132 parallel to the track. |
