| 摘要 |
PURPOSE:To detect easily and quickly the actual linear speed of a disk record for a disk record reproducer of an optical compact disk (CD) type, by using a prescribed address, an expected address, a prescribed linear speed and an arriving address which are all stored to a memory means previously. CONSTITUTION:When a program is started, a microcomputer incorporated to a control circuit 201 searches a prescribed address Tp stored previously to an ROM 214 through a pickup 207, then shifts the pickup 207 up to a position ahead of N tracks via an interface and an external control circuit 203. Thus an arriving address TD where the pickup actually reaches can be read out of an address detecting circuit 211 and stored to an RAM 213 via the interface and the micro- computer. The address Tp, an expected address TT, a prescribed linear speed VT stored previously to the ROM 214 are used together with the address TD stored in the RAM 213 to calculate an equation I . Thus the acutal speed VD of a disk record is obtained. |
