| 摘要 |
PURPOSE:To enable to make magnetic recording and reproduction in addition to optical reproduction, by forming a reflecting film layer, made of a ferromagnetic metal, on the main surface of a discoid subtrate where pits having information recorded are formed. CONSTITUTION:On the signal surface of substrate 1 to which pits in the signal recording surface of an original disk have been transferred, reflecting film 2 made of a ferromagnetic metal is provided by sputtering and on it, protection layer 3 is further provided. Two disks consisting of those three layers are stucked to each other with protection layers 3 inside to form a both-sided preproduction type disk. This disk is irradiated with a reading light beam at the side of substrate 1 and reflected light from reflecding film 2 is detected for optical signal reproduction. Further, reflecting film 2 of this ferromagnetic metal is magnetized by using a means, such as magnetic head, to perform magnetic recording and reproduction. |
