| 摘要 |
PURPOSE:To prevent unnecessary recording even when a light spot stops on a recording medium for a long time by obtaining a tracking signal with the beam spot having the largest luminous amount when the beam spot exists at the outside of information recording region of the recording medium. CONSTITUTION:Plural beam spots are projected at the same time on the recording medium, and at least one beam spot is used to obtain a tracking signal confirming the scanning position of the beam spot for recording or reproduction, and when the said beam spot group exists at the outside of the information recording area of the recording medium, a tracking signal from the beam spot having the largest luminous amount is obtained. For example, when each light spot moves relatively to a position IV, since light spots 7, 9 come to track bars 35, 26, a luminous amount change is caused to sensors 19B, 19C corresponding to the light spots 7, 9 and the signal is inputted to a kick circuit from the sensors 19B, 19C.
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