| 摘要 |
PURPOSE:To reduce the access time of a 1-track jumping scan, by synchronizing the jumping timing of an information track and the horizontal synchronous signal of a record information when scanning the information recorded on an optical recording medium and then completing the jumping action within one section of horizontal scanning. CONSTITUTION:The information reproduction signal supplied from a photodetector 4 is demodulated and supplied to a demodulator 21 to obtain a video signal when a scan is given concentrically or spirally to an information track that is recorded on a disk-type optical recording medium which is driven rotatively. The video signal is supplied to a horizontal synchronous separating circuit 22 to give a separation to the horizontal synchronous signal. Then a pulse is produced by a jumping drive signal generator 23 and based on a jumping command signal which is synchronous with the horizontal synchronous signal, and applied to a galvano-mirrow of a beam deflecting device 24. Thus a jumping action is completed within a section of horizontal scanning. |
