| 摘要 |
PURPOSE:To attain remarkable speed up of retrieval by switching electrically plural optical heads so as to retrieve an object track. CONSTITUTION:A track band on a recording medium 10 is assigned to plural optical heads 20A-20D and recording/reproduction/retrieval is attained by using electric switching of the plural optical heads 20A-20D and inclination of a light beam. When a recording/reproduction system 15 of a signal of channel 1 and an optical head 20B are selected, for example, a track band switching circuit 30 selects a semiconductor laser drive circuit 12B of an object address to drive selectively the optical head 20B and a track jumping circuit 31 retrieves an object track to record a signal desired to be recorded. Thus, the waiting time is kept to a switching time of the optical head and a jumping time of the light beam only so as to improve remarkably the throughput of data. |
