公开(公告)号：JPH06215438A

公开(公告)日：1994-08-05

申请号：JP31297193

申请日：1993-12-14

Applicant: IBM

Inventor： BUREA IAN FUINKERUSHIYUTAIN ,  DEEBUITSUDO AANESUTO KOORU

IPC: G11B7/00 ,  G11B7/0045 ,  G11B7/0055 ,  G11B7/09 ,  G11B7/125 ,  G11B11/10 ,  G11B11/105 ,  G11B7/135

Abstract: PURPOSE: To minimize laser feedback during data recording by providing a controlling means for enabling the establishment of a state a little out of focus selected during the data recording operation. CONSTITUTION: An optical disk 10 reflects a beam supplied from a laser 11 through an objective condenser lens 19 and an optical system 300. The optical system 300 changes the direction of a reflected light, and directs it along an optical path 22 to a focus detector 304. The focus detector 304 supplies a focal error signal to a condensing circuit 23'. The circuit 23' is connected to a focal coil 303 so that a proper focus control signal for activating the movement of a lens carriage 32 can be supplied. In this constitution, it is preferable that a focus 330 is not directly abutted to the reaction layer of the optical disk 10 by shifting a little the focus of the lens during a writing processing. Therefore, the focus servo of the circuit 23' can establish and hold the focus 330 at a position out of focus relatively to the surface of the optical disk 10.

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.