公开(公告)号：JPH10134492A

公开(公告)日：1998-05-22

申请号：JP14499397

申请日：1997-06-03

Applicant: IBM

Inventor： KASIRAJ PRAKASH ,  MEEKS STEVEN WAYNE ,  REILEY TIMOTHY CLARK

IPC: G11B19/00 ,  G11B5/55 ,  G11B21/21 ,  G11B19/04

Abstract: PROBLEM TO BE SOLVED: To provide the magnetic recording disk drive equipped with a magneto-resistance(MR) read head for detecting external impact by utilizing a thermal resistance effect in an MR head signal and suppressing write-in operation. SOLUTION: The magnetic recording disk drive equipped with the MR read head 60 is equipped with an impact detecting circuit 55 for responding to a thermal resistance signal contained in the signal from the head. The MR head 60 is heated by a bias current, and is supported on a head carrier close to the surface of the disk 10. A space between the carrier 13 and the disk is changed by external impact upon the disk drive, and hence the heated head is cooled by, the disk, so that a head temp. is varied. Such a variation in the temp. is reflected as the thermal resistance signal including modulation of a base line voltage level to the signal from the head. Positive and negative deviation of this thermal resistance signal is compared with a prescribed threshold voltage level by the impact detecting circuit 55.

公开(公告)号：DE69722857D1

公开(公告)日：2003-07-24

申请号：DE69722857

申请日：1997-04-02

Applicant: IBM

Inventor： KASIRAJ PRAKASH ,  MEEKS STEVEN WAYNE ,  REILEY TIMOTHY CLARK

IPC: G11B19/00 ,  G11B5/55 ,  G11B21/21 ,  G11B19/02 ,  G11B33/08

Abstract: A magnetic recording disk drive with a magnetoresistive (MR) read sensor or head has a shock and vibration detection circuitry responsive to a thermoresistive signal contained in the signal from the head. The MR head is heated by an electrical bias current and is supported on the head carrier near the surface of the disk. External shock or vibration to the disk drive alters the spacing between the carrier and the disk, which causes fluctuations in the head temperature due to cooling of the heated head by the disk. These temperature fluctuations are reflected in the signal from the head as a thermoresistive signal comprising modulation of a baseline voltage level. The shock detection circuitry compares positive and negative excursions of this thermoresistive signal with a predetermined threshold voltage level. When the threshold is exceeded, indicating an external shock or vibration in excess of an allowable limit, writing of data is inhibited.