| 摘要 |
PROBLEM TO BE SOLVED: To provide the compatibility reproducing even related to the optical disk except the CD-RW system in addition to the optical disk of the CD-RW system with the same conditions by gain switch of two stages with respect to an optical information recording/reproducing device constitution making an optical disk of a CD-RW (CD-rewritable) system an object. SOLUTION: Laser power of a laser light source 1 at a reproducing time is set differently in the case for the optical disk of the CD-RW system from in the case for the optical disk excepting the CD-RW system having large different reflectance, and as the result, reproducing reflected light quantities from either optical disks are made so as to become nearly equal also. Thus, the gain at the reproducing time related to the gain of a current-voltage conversion amplifier 12a is commonized even for either optical disks, and the number of switching the gain is dealt with perfectly only two stages of a recording time and a reproducing time. |
