| 摘要 |
PURPOSE:To increase the storage quantity by irradiating the first light beam and the second light beam on the center of an inter-groove part, and on a position which has been separated by about (d) in the direction vertical to the running direction of the groove, from the center of the inter-groove part, respectively, in case the groove width is about 2d. CONSTITUTION:Width of a groove part and inter-groove part of a recording medium are d and 2d, respectively, and a recording area of width 2d and an intermediate area of width d are provided alternately. To the recording medium 4, a magnetic field H is applied downward, and recording and erasion are executed by a light beam 1 and a light beam 2, respectively. In this case, in a recording area 9 which has been magnetized upward in advance, a pit 7 which has been magnetized downward is formed, and a recording area 10 is magnetized downward uniformly. On the other hand, an upward magnetic field H is applied to the recording medium 4, and when recording and erasion are executed by the light beam 2 and the light beam 1, respectively, a pit 8 which has been magnetized upward is formed in a recording area 10 which has been magnetized downward, and the recording area 9 is magnetized upward uniformly. By repeating this operation, information is recorded in one of the recording areas 9 and 10 at all times. In this way, the storage capacity is increased.
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