| 摘要 |
PURPOSE:To execute easily a random access, and to make an angular velocity invariable on the way of transmission of information by determining the angular velocity in accordance with a block to which the head track belongs, when recording or reproducing of one piece of information is started, and holding the determined angular velocity until recording or reproducing of one information is completed. CONSTITUTION:When a recording start signal P is inputted, a gate circuit 18 opens a gate, and a track address extracted to a signal processing part 17 is inputted to an operational comparator 19 through the gate circuit 18. The operational comparator 19 compares and operates the inputted track address and the information (the relation of a track address and an angular velocity) prepared in advance in a table, and determines an angle in that time. A digital value corresponding to the determined angular velocity is converted to an analog value by a D/A converter 21, and inputted to a motor driving part 22, by which an optical disk 14 rotates at a constant angular velocity. Even if recording of one information extends to the following block 5, this angular velocity is not varied until its recording is completed. |
