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Browse Prior Art Database

Laser/Capacitive Disk Flatness Correlation Tool

IP.com Disclosure Number: IPCOM000116632D
Original Publication Date: 1995-Oct-01
Included in the Prior Art Database: 2005-Mar-31
Document File: 4 page(s) / 92K

Publishing Venue

IBM

Related People

Crump, DS: AUTHOR [+4]

Abstract

Disclosed is a method of making the Correlation of Disk Flatness measurement possible between the Rudolph Laser and any commercial Capacitive probe.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Laser/Capacitive Disk Flatness Correlation Tool

      Disclosed is a method of making the Correlation of Disk
Flatness measurement possible between the Rudolph Laser and any
commercial Capacitive probe.

      The disk drives manufacturers specify their requirements based
on utilizing the Capacitive Probe as a measurement tool.

      The disclosed tool was developed utilizing both the Rudolph
Laser and the Capacitive probe equipment from ADE.  This tool is
currently used to study the correlation of specifications between the
Capacitive probe and the Rudolph laser.

      The tool was designed to work with different disk sizes ranging
from 275mm down to 45mm.  The tool is comprised of the following
components:
  1.  Capacitive Probe (1)
  2.  XY Micrometer Stages (2)
  3.  Capacitive Probe Readout (3)
  4.  Capacitive Probe Controller (4)
  5.  Laser (5)
  6.  Optic (6)
  7.  Computer (7)
  8.  Monitor (8)
  9.  Linear Actuator (9)
 10.  Disk Selection Knob Mechanism (10)
 11.  Spindle (11)
 12.  Spindle Controller (12)
 13.  Disk (13)
 14.  Disk Clamp (14)

      Operation - Measurement data is taken while the disk is
rotating.  In order to obtain a true correlation, the sensing device
for both the laser and the probe, must be placed at the same position
on the disk.  To accomplish this, both the laser optic prism and the
probe are mounted at the end of the linear actuator.  The travel of
the linear actuator is controlled by the computer.  The distance of
travel is programmed to be used for both the laser and the probe.
The laser optic prism is mounted offset from the probe.  Both the
laser beam and the probe head must be aligned to the center of the
spindle which is used as the reference point.  During the
measurement, they both move radially towards the outer diameter of
the disk in the same pattern.

      Selecting the disk size is accomplished via the disk selection
knob mechanism.  The XY micrometer stages are utilized to adjust the
probe with precisi...