| 摘要 |
PURPOSE:To perform both erasing and recording simply only by one procedure by forming the images of a recording optical spot and an erasing spot on a recording medium and applying magnetic fields to these spots reversely with each other. CONSTITUTION:A magnet 19 is constituted of a magnet part 19a magnetized by N and S poles in the turning direction of a disc 6 and york parts 191, 192 and the leading end of the S pole york 191 and the leading end of the N pole york part 192 are attached so as to be opposed to a spot 17a of recording laser light 17 from a laser generator 15 on the disc 6 and a spot 18a of erasing laser light 18 from a laser generator 16 on the disc 6 respectively. If a new signal is recorded in a prescribed position on the disc 6 by the laser light 17 and a recording magnetic field HR after erasing a signal already recorded on said prescribed position by the laser light 18 and the erasing magnetic field HE, the signals can be erased and recorded only by one procedure. |
