| 摘要 |
PURPOSE:To optimize setting conditions of a rotational speed and a signal process of a disk according to obtained recording density by respectively constituting a read-in area and a program area with a recording density corresponding to wavelengths of a 780nm and a 670nm or below and reproducing them with a laser beam. CONSTITUTION:The read-in area and the program area are constituted on a CD with the recording density corresponding to wavelengths of 780nm and the 670nm or below. The recording information on the CD is read out by the laser beam LB, and is decoded to the data of a CD format by a CD signal process part through a preamplifier. The data are sent to an audio circuit, and are converted into signals of L and R channels to be outputted. Further, a periodical signal and an error correction code, a subcode, etc., for auxiliary data among the decoded data are sent to a system controller, and are performed with a process required for control. Further, the output of the preamplifier is inputted to a servo circuit, and is used for tracking control and focusing control. |
