公开(公告)号：JPH0495237A

公开(公告)日：1992-03-27

申请号：JP21176190

申请日：1990-08-13

Applicant: APPLE COMPUTER

Inventor： POORU JIEI UEERENBAAGU

IPC: G11B7/24 ,  G11B7/12

Abstract: PURPOSE: To make it possible to obtain an optical data memory system which is excellent in a dust defocusing effect and is low in electric power consumption by using an optical data recording medium provided with a recording layer in the uppermost part and a reflection layer in the lowermost part and a combined optical/magnetic head. CONSTITUTION: The optical data memory system is constituted by using the optical data recording medium 130 provided with the recording layer 60 in the uppermost part and the reflection layer 80 in the lowermost side and the combined optical/magnetic head 140. Then, the incident light beam 10 on the front surface arrives at a focus existing at the recording layer 60 by passing the recording layer 60, a substrate layer 70, reflect from a base 80 and again pass the substrate 70 in a reverse direction. In such a case, the optical path turns back and, therefore, the substrate 70 may be formed to a half thickness even if the optical path length is the same. The optical head and the magnetic head are combined in such a manner. Since the movement of these heads as a single unit is made possible, the increased speed and the improved reliability are resulted. On the other hand, the reduction in the cost and the electric power consumption is resulted.