Samsung Electronics Co., Ltd.

Dongman Kim

Sang Hoon Chu

A hard disk drive using an increase in servo address mark delays to create a touchdown flag in response to a slider making contact with a rotating disk surface while accessing a track. This may be used particularly when the track being accessed is located away from the Inside Diameter (ID). The hard disk drive may further use resistive heater electrical readings to determine the touchdown flag for track locations near the ID. The hard disk drive may be calibrated during manufacture and/or may be recalibrated in the field with this method. The calibrated hard disk drive is a product of this method. The method may be used during normal access operations and/or may be embodied as a program system residing in computer readable memory for instructing a computer operating the hard disk drive, where the computer and/or the memory may or may not be included in the hard disk drive.

Method and apparatus for estimating touchdown of a slider in a hard disk drive

A hard disk drive is disclosed including a voice coil motor and a magnetic sensor communicating with a control circuit. A magnetic sensor reading is created and used to stop access operations in response to the reading of an external magnetic field that may be strong enough to disrupt a slider accessing a rotating disk surface. Also disclosed are a main flex circuit and head stack assembly including the magnetic sensor for use in a hard disk drive. Control circuits and processors are disclosed for receiving the magnetic reading to stop access operations in hard disk drives. The hard disk drive may be a Perpendicular Magnetic Recording (PMR) hard disk drive.

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Campbell, CA, United States of America

Dongman Kim