| 摘要 |
PROBLEM TO BE SOLVED: To make it possible to obtain a desired write speed without using a photo-detector having a necessary frequency band by using a photo-detector with a response speed slower than a write speed of an optical disk device, and correcting an error of a light emitting power of a laser beam source generated due to the insufficient frequency band of this photo-detector. SOLUTION: An light-emitting control error of semiconductor laser 17 generated due to an insufficient frequency band of a photo-detector 21 is corrected by correcting a pseudo-offset of outputs of sample-and-hold circuits 26, 27. If the pseudo-offset of the sample-and-hold circuits 26 of the photo-detector 2 is expressed by +α, a correction voltage 1 (-α) is added to the sample-and- hold circuit 26 to eliminate a control error of a read power control (light- emitting power control of the semiconductor laser 17). If the pseudo-offset of the sample-and-hold circuits 27 is expressed by -α', a correction voltage 1 (+α') is added to the sample-and-hold circuit 27 to eliminate the control error of the read power control. |
