公开(公告)号：JPH05114254A

公开(公告)日：1993-05-07

申请号：JP30233191

申请日：1991-10-22

Applicant: SONY CORP

Inventor： MUTO TAKAYASU ,  SUZUKI YASUAKI ,  NAKANO KATSUHIRO

IPC: G11B20/18 ,  G11B21/10

Abstract: PURPOSE:To improve the error rate of a magnetic disk device and, in addition, to prevent the occurrence of a seek error which occurs when a track to which no head position control can be performed exists. CONSTITUTION:A head position detecting section 13 supplies the output signal of an R/W amplifier 131 to an equalizer 132 which supplies the output signal to a positional information generation circuit 138 through a pulse detection circuit 133 and servo detection circuit 134 and, at the same time, signals to the circuit 138 through an envelope detection circuit 135, integration circuit 136, and A/D converter 137. In case the section 13 detects the presence of abnormality in a track as a result of searching the servo sector area signal SV-PRT and servo error detecting signal SV-ERR of a servo pattern, the section 13 detects the abnormality by discriminating a servo turned-off state and checks all tracks for the defective point by rearranging the data of the defective point.

公开(公告)号：JPH03187071A

公开(公告)日：1991-08-15

申请号：JP32605489

申请日：1989-12-18

Applicant: SONY CORP

Inventor： MUTO TAKAYASU ,  OSATO MAMORU ,  SUGITA JUNKICHI ,  KASHIWAGI MASAMI ,  TANAKA TORU ,  SETO HIDEKAZU

IPC: G11B21/10

Abstract: PURPOSE:To efficiently perform the tracking control with a high precision by using two servo tracks for one arbitrary phase and one servo track for each phase of the position detection signal of a magnetic head formed on a magnetic disk to correct the detection error. CONSTITUTION:Servo tracks TS1 and TS0 having a try bit servo pattern are formed in the innermost periphery and the outermost periphery of each of respective disk faces 3A to 3D of, for example, two magnetic disks 3, and four servo tracks TS1M to TS4M are formed in an about center of the data area of each of these disk faces. An extent of off-track correction required for a pertinent recording track is calculated based on the inclination (distribution) of the extent of off-track obtained from tracks TS0 and TS1 and respective reference extents of off-track of detection signals DET1 to DET4 obtained from tracks TS1M to TS4M and is outputted to a D/A converter 35 to minutely shift a magnetic head 4A, and the head just tracks a desired recording track on the disk face 3A.

公开(公告)号：JPH02122482A

公开(公告)日：1990-05-10

申请号：JP27532588

申请日：1988-10-31

Applicant: SONY CORP

Inventor： MUTO TAKAYASU ,  KAWABATA TOMOMIKI

IPC: G11B21/08

Abstract: PURPOSE:To attain stable and excellent seeking by means of zone recording even when the boundary positions of sectors are irregular by executing the seeking of a track with the use of an externally positioned sensor. CONSTITUTION:A recording surface is divided into plural zones by the radius positions of the track, a disk 1 is provided which is specified so that the number of the sectors provided at every track in the zone may become smaller on the inner side, and the position of a head arm 4 is detected by the externally positioned sensors, namely, a scaler 8 and a photosensor. Further, the seeking of the desired track is executed by means of a sensor output by a control circuit 11. In such a way, by executing the seeking of the track with the use of the externally positioned sensors 8 and 10, the stable and excellent seeking is attained by the zone recording even when the boundary positions of the sectors are irregular.