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Using Optical Guidance for a Hard Disk Drive Head Assembly

IP.com Disclosure Number: IPCOM000014971D
Original Publication Date: 2001-Aug-01
Included in the Prior Art Database: 2003-Jun-20
Document File: 1 page(s) / 39K

Publishing Venue

IBM

Abstract

Disclosed is a method for optically guiding the read/write head for a computer hard disk drive. Rather than relying on the drive head assembly motor to position the drive head over the drive surface, the proposed method uses a low-power laser to read the current drive-head position and guide the drive head assembly to the proper position above the drive surface using a servo-controller in the motor.

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Using Optical Guidance for a Hard Disk Drive Head Assembly

   Disclosed is a method for optically guiding the read/write head for a computer hard disk drive. Rather than relying on the drive head assembly motor to position the drive head over the drive surface, the proposed method uses a low-power laser to read the current drive-head position and guide the drive head assembly to the proper position above the drive surface using a servo-controller in the motor.

     The preferred implementation adds a very thin reflective polymer substrate to the surface of the hard disk drive. This substrate is magnetically and electrically neutral so that it cannot interfere with the drive heads and cannot induce spurious magnetic fields. By using a low-power laser to read predefined patterns in the substrate, it can accurately determine its position relative to the substrate. By adding a servo-controller to the hard-disk drive motor that responds to the position data from the laser, the drive head can be positioned with greater accuracy.

     In addition to reading the horizontal (x-y, r-theta) position of the drive head, the preferred implementation also splits the beam so that the laser can also read the vertical (z) position of the drive head, thus allowing the drive head to adjust the magnetic field applied while reading and writing data on the drive surface. Such accuracy in the x-y (r-theta) position increases the density of data that can be read and written to the disk. The increased...