Multiple beam optical disk apparatus with multiple clock extracting

Abstract

A disk recording and reproducing apparatus using two light beams has a disk driving section for loading a disk-shaped record medium having recording tracks and for rotating the disk-shaped record medium, an optical system having a light beam generating source, a light beam splitting device for splitting a light beam to provide at least a main beam and a sub beam, an optical path forming device for respectively causing the main beam and the sub beam to become incident on two adjacent recording tracks in the disk-shaped record medium loaded on the disk driving section and a photo-detecting device for detecting the condition that at least the sub beam from the disk-shaped record medium loaded on the disk driving section is affected by the recording track. Also provided is a disk rotation control section for controlling the disk driving section such that a relative moving speed of the recording track relative to the main beam incident on the recording track becomes constant, a recording operation section causing the information to be recorded on the recording track on which the main beam becomes incident, and a reproducing operation section for generating a read-out information signal based on a detected output of the sub beam from the photo-detecting device. The resultant read-out information signal is written in a memory at a rate corresponding to the read-out information signal and the read-out information signal written in the memory is read out again at a predetermined reading rate to generate a reproduced information output.