The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 18, 2001
Filed:
Mar. 11, 1999
International Business Machines Corporation, Armonk, NY (US);
Abstract
A magnetic disk tester which also incorporates a sensor such as an AFM or MFM is described. The device is able directly and quickly to detect and characterize sub-micrometric defects on the surface of magnetic disks. A process for finding and characterizing defects on a magnetic disk according to the invention comprises the steps of rotating the magnetic disk using a spindle motor; writing data on the magnetic disk at selected positions; finding a position on the magnetic disk having a defect which produces an error when reading the data from the magnetic disk; determining coordinates of the defect referenced from an index on the disk; stopping the spindle motor; positioning a sensing device such as an AFM or MFM head over the defect; and sensing characteristics of the defect which aid in determining a cause of the defect. A magnetic disk examination device embodying the invention comprises a spindle rotably connected to a spindle motor; a magnetic read/write head mounted on an actuator; a magnetic read/write tester for writing then reading magnetic data on the magnetic disk while rotating to find a position on the magnetic disk which produces read errors; a sensor mounted on an actuator which can be a second actuator or the same as the one for the read/write head; a positioning system which places the sensor at the position of the error while the magnetic disk is stationary; and a data acquisition system which gathers data using the sensor.