| 摘要 |
PURPOSE:To eliminate interference between light spots and to make setting operation stable by putting off light except a light spot for detecting a focusing error signal until setting operation is completed at the time of focus setting. CONSTITUTION:A semiconductor laser diode 1 has two light emitting section 1a, 1b and the laser 1a is a light spot for detecting focus error. A control section makes a disk 5 rotate, turns on the laser 1a, and moves an object lens 4, at the time of focus setting. During the time, since a servo signal detecting light flux is in out of focus, an adjacent detector for detecting light for verifying also is in out of focus in light detector 9, 10. However, since the laser 1b for verifying spot is put off, a light flux does not exist on the surface of the detector and interference between light spots does not occur. After that, the laser 1b is turned on at the time of finish of setting operation by the laser 1a, and a recording and reproducing state by the laser 1a and 1b is obtained. Thereby, interference between light spots is prevented and setting operation is stabilized. |
