公开(公告)号：JP2000260142A

公开(公告)日：2000-09-22

申请号：JP5998199

申请日：1999-03-08

Applicant: IBM

Inventor： KUROKI KENJI ,  ALBRECHT THOMAS ,  SAI FUMINORI ,  NAKAGAWA YUZO ,  KOIDE NOBUHISA ,  MURAI MASASHI ,  TAKAHASHI HIROSHI ,  TIMOTHY RILEY ,  ARNO CLASSEN

IPC: G11B21/02 ,  G11B19/04 ,  G11B21/12 ,  H02P8/12

Abstract: PROBLEM TO BE SOLVED: To provide a retract circuit capable of dealing with miniaturization and power supply voltage reduction. SOLUTION: Concerning a retract circuit 13, while a device power source Vcc is turned on, a retract capacitor Cr is charged by a boost voltage Vup (=3×Vcc) generated by a booster circuit 26. When the device power source Vcc is turned off and a voice coil motor (VCM) driver 12 stops operating, a power source OFF is detected by a power source OFF detecting circuit 21 and retract delay time Td is provided by a retract delay circuit 22. After the lapse of the retract delay time Td from the OFF of the device power source, switch circuits 24 and 25 are turned on by a retract driving circuit 23, the retract capacitor Cr charged with the boost voltage Vup is discharged, a discharging current is supplied to a voice coil 5a and a head assembly is retracted.

公开(公告)号：JP2002298307A

公开(公告)日：2002-10-11

申请号：JP2001097183

申请日：2001-03-29

Applicant: IBM

Inventor： SUZUKI HIROMASA ,  ASANO HIDEO ,  NAGANO ARIYOSHI ,  NAKAJIMA MICHIO ,  IKEDA MASAOMI ,  MURAI MASASHI

IPC: G11B5/027 ,  G11B5/00 ,  G11B5/012 ,  G11B5/035 ,  G11B5/09

Abstract: PROBLEM TO BE SOLVED: To improve the overwrite performance in the initial stage of write. SOLUTION: A write current W1 which is obtained by adding a boost current (Wboost) to a nominal current (Wnom) is supplied to a write head in the initial stage of the write, and after that time, the write current W2 consisting of the nominal current (Wnom) is supplied to the write-head.