公开(公告)号：JPS6473569A

公开(公告)日：1989-03-17

申请号：JP23055887

申请日：1987-09-14

Applicant: YAMAHA CORP

Inventor： TOMIZAWA TOSHIO ,  KUMAOKA MICHIAKI ,  NARISAWA SADAYUKI ,  TAKABAYASHI OSAMU ,  FUJIWARA KAZUNOBU

IPC: G11B20/14 ,  H03K5/00

Abstract: PURPOSE:To enable a synchronizing signal to be stably fetched even when high speed searching or the like is executed by canceling a window with the aid of the command of an operation mode where the synchronizing signal cannot be continuously obtained in a prescribed cycle. CONSTITUTION:When the command of the high speed searching is given, an AND circuit 12 can be operated through an OR circuit 33, the synchronization detection window is always in a releasing state and all synchronization detection signals are fetched. That means, the window is released by the command of the operation mode without waiting the synchronizing signal is off from the window similar to a conventional circuit. As the result, the window releasing can be executed at once. Thus the synchronizing signal can be relatively stably fetched even when the high speed searching is executed.

公开(公告)号：JPS6472359A

公开(公告)日：1989-03-17

申请号：JP22802387

申请日：1987-09-11

Applicant: YAMAHA CORP

Inventor： TOMIZAWA TOSHIO ,  KUMAOKA MICHIAKI ,  NARISAWA SADAYUKI ,  TAKABAYASHI OSAMU ,  FUJIWARA KAZUNOBU

IPC: G11B27/28 ,  G11B20/10

Abstract: PURPOSE:To exactly execute after-recording by counting a reproducing clock or its corresponding clock, and correcting a numerical value, based on actual address information as a reference while calculating a numerical value corresponding to a head position on a track. CONSTITUTION:A reproducing clock or its corresponding clock (reference clock, etc.) is counted by calculating means 14, 16, 18 and 20, and while calculating a numerical value corresponding to a head position on a track, the numerical value is corrected, based on actual address information as a reference, by a correcting means 10. Accordingly, the numerical value corresponding exactly to the head position is obtained, and from this numerical value, it is detected exactly by a detecting means 22 that the head position on the track has reached a prescribed position. In such a way, after-recording can be executed exactly.