公开(公告)号：JPH0917058A

公开(公告)日：1997-01-17

申请号：JP14745096

申请日：1996-06-10

Applicant: IBM

Inventor： PATORITSUKU KURINTON AANETSUTO ,  DEEBITSUDO AANESUTO KOORU ,  BUREA IAN FUINKERUSHIYUTAIN ,  GUREN ARAN JIYAKETSUTO ,  ERUNESUTO ESUTEBAN MARINEERO

IPC: G11B7/24 ,  G11B7/125 ,  G11B11/10 ,  G11B11/105 ,  G11B20/18

Abstract: PROBLEM TO BE SOLVED: To sufficiently define recording mark edges and to decrease the thermal interference between recording marks of close spacings by modulating a laser among three ways of output levels at the time of forming the recording marks. SOLUTION: The laser 408 is controlled by a processor 404, a memory storage device 406 and a laser driver 500. The laser 408 is optically coupled to optical elements 414 and 416 for directing a light beam 418 onto a disk 402. The light reflected from the disk 402 is detected by a feedback detector 422 coupled to a data detector 420 and laser driver 500 coupled to a processor 404. A starting magnet 424 for generating a magnetic field in a first direction and a bias magnet 426 for generating the magnetic field in a second direction opposite thereto are positioned in proximity to the disk 420. The disk 402 has a substrate 430, at least one reference layer 432 and a memory layer 434.

公开(公告)号：JPH0644600A

公开(公告)日：1994-02-18

申请号：JP14182691

申请日：1991-06-13

Applicant: IBM

Inventor： DEEBITSUDO AANESUTO KOORU ,  JIYURIAN RUUKOUITSUTSU

IPC: G11B7/00 ,  G11B7/004 ,  G11B7/0045 ,  G11B7/0055 ,  G11B7/125 ,  H01S5/06 ,  H01S5/062 ,  H01S5/0683

Abstract: PURPOSE: To provide a laser driving device provided with a means for appropriately calibrating the intensity of the output light of a laser used for an optical disk recorder or the like. CONSTITUTION: At the time of calibration, the laser 14 emits light with the control of a laser control part 15 and a photodiode 31 receives the light. Voltage signals corresponding to the light emitting levels to comparators 35 and 40 through a line 34. A minimum reference value CALVR1 and a maximum reference value CALVR2 are supplied to the comparators 40 and 35 through switches 41 and 36. A micro processor 20 stepwise increases the input value of a digital/ analog converter(DAC) 23 so that the voltage signal of the line is contained in a range between the minim/maximum reference values. The input values DACmin and DACmax of DAC 23, which are equivalent to the maximum/ minimum reference values, are obtained and are stored in a table 43. The efficient value E of DAC, which is obtained by the minimum/maximum reference values and the input values DACmin and DACmax, is stored in the table 43 and a current value for driving the laser 14 at a prescribed mode by the values is set.