发明名称 Recording condition determination method and apparatus upon execution of over-write operation on magnetooptical disk by heat shut off method and pulse train method, and magnetooptical recording method and apparatus
摘要 In a magnetooptical recording method and apparatus the intensity of a laser beam to be radiated onto an over-write capable magnetooptical disk is raised from PL to an intensity PH higher than PL, the intensity is reduced to an intensity PLT lower than PH after PH is maintained for a time TW1, the laser beam is intensity-modulated at a period Tp between PLT and an intensity PW2 higher than PLT so as to form a mark on the magnetooptical disk by a high-temperature cycle, thereafter, the intensity is reduced to an intensity PLB lower than PL, and the intensity is raised to PL after an elapse of a time Toff. The intensity PL is selected from an intensity range defined between an upper limit and a lower limit. The upper limit is a laser beam intensity for maintaining a pre-heat state in which a temperature on the magnetooptical disk becomes a predetermined temperature THETA pre, and is also an intensity which does not cause the high-temperature cycle. The lower limit is an intensity at which a mark formed by the high-temperature cycle can be erased. At least one of PL, Toff, and PLB is controlled to achieve the pre-heat state within a time until the intensity is raised to PH again. At least one of PW2, PLT, and a time TW2 for maintaining PW2 is controlled, so that a temperature, after an elapse of TW1, at a peak temperature position or a spot center position of the laser beam radiated onto the magnetooptical disk surface becomes equal to a temperature after an elapse of TW2.
申请公布号 US5420837(A) 申请公布日期 1995.05.30
申请号 US19930141620 申请日期 1993.10.27
申请人 NIKON CORPORATION 发明人 SAITO, JUN;KURITA, SHINICHI
分类号 G11B7/0045;G11B7/125;G11B11/105;(IPC1-7):G11B11/00 主分类号 G11B7/0045
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