| 摘要 |
PROBLEM TO BE SOLVED: To enable high accuracy alignment by adjusting the position of a light spot from an incident side light source on a recording medium based on changes in the power of the other side light source. SOLUTION: The emitting point of a semiconductor laser 201 for reproducing and the position of a light spot on an optical card 1 are in the conjugate relation. When a light spot of a semiconductor laser 202 for recording is to be adjusted in the three dimensions of x, y and z, the emitting point of the recording laser 202 is regarded as conjugate with the emitting point of the reproducing laser 201 by controlling the recording light spot on the optical card 1 to be three-dimensionally consistent with the reproducing light spot. When the position of the light spot of the recording laser 202 is to be adjusted, the recording light beam can be introduced into the emitting point of the reproducing laser 201 by a dichroic mirror 204. Therefore, the position in x, y, z directions of the light spot of the recording laser 202 is adjusted based on the oscillation state of the reproducing laser 201 and the recording laser 202 is fixed at the position where the variance in the oscillation state of the reproducing laser 201 is the max. |
