Browse Prior Art Database

Automated 2D Stiction and Head-Crash Camera

IP.com Disclosure Number: IPCOM000034636D
Original Publication Date: 1989-Mar-01
Included in the Prior Art Database: 2005-Jan-27
Document File: 4 page(s) / 111K

Publishing Venue

IBM

Related People

Feliss, NA: AUTHOR

Abstract

A non-contact optical system is described by which mechanical movements such as head stiction or a head crash, can be continuously monitored from the beginning of the phenomenon. The optical system (Fig. 1) comprises a white light source 1 which illuminates the surface of the disk 2, and the reflected light is captured by an optical charge-coupled device (CCD) camera 3 which includes an array of photo-diodes. A voltage output is produced which is directly proportional to the intensity of the reflected light. (Image Omitted) The specific embodiment of the system shown in Fig. 2 is adapted for capturing a wear track before and after a head crash. In this case a 1D arrangement of photo-diodes 4 is sufficient to capture the light image.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 72% of the total text.

Page 1 of 4

Automated 2D Stiction and Head-Crash Camera

A non-contact optical system is described by which mechanical movements such as head stiction or a head crash, can be continuously monitored from the beginning of the phenomenon. The optical system (Fig. 1) comprises a white light source 1 which illuminates the surface of the disk 2, and the reflected light is captured by an optical charge-coupled device (CCD) camera 3 which includes an array of photo-diodes. A voltage output is produced which is directly proportional to the intensity of the reflected light.

(Image Omitted)

The specific embodiment of the system shown in Fig. 2 is adapted for capturing a wear track before and after a head crash. In this case a 1D arrangement of photo-diodes 4 is sufficient to capture the light image. A typical scan behind one rail of the magnetic head slider 5 with and without a wear track is shown in Figs. 3A and 3B. The graph in Fig. 3A shows a video output of low intensity since the magnetic medium is undisturbed and is light absorbing. In Fig. 3B, a portion of the magnetic layer is worn away with the result that light reflectance is increased due to exposure of the highly reflecting aluminum substrate.

(Image Omitted)

Head stiction is defined as the resistance of the head to mechanical shear in the direction of disk motion. An embodiment to monitor stiction is shown in Fig. 4. In this embodiment a 2D CCD camera 6 is used to measure displacement. The 2D CCD camera is positioned above...