LASER POWER CONTROLLER AND OPTICAL DISK DEVICE

摘要

A power controller for controlling the power of a light source for emitting a light beam directed to an optical medium, comprising a reflected light detector for detecting the light reflected from the optical medium when the light beam is made to track a track of the optical medium, a calculating unit for calculating the transmittance to light from the surface of the disk to a recording layer by using the reflected light or the intensity of the light beam at the recording layer of the medium, and power control means for controlling the power of the light beam of the light source from the results of the calculation by the calculating unit.