# US 8,542,453 B2 · Inspection method and inspection apparatus of magnetic disk > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,542,453 B2 - Document ID: US8542453B2 - Status: Granted - Kind: B2 - Application number: 13/345,763 - Filed: 2012-01-09 - Published: 2012-07-12 - Granted: 2013-09-24 - Earliest claimed: 2011-01-12 - Assignees: Hitachi High-Technologies Corporation - Applicants: Kyoichi Mori; Masanori Fukawa - Inventors: Kyoichi Mori; Masanori Fukawa - Web page: https://patentgrep.com/patent/US8542453B2 ## CPC - G11B 5/84: Processes or apparatus specially adapted for manufacturing record carriers - G11B 5/607: {using thermal means} - G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R) ## Abstract An inspection method and inspection apparatus of a magnetic disk are provided. A gliding test and a certification test are performed at the same time by simultaneously moving a head for the certification test and a head for the gliding test with a heat distortion utilization mechanism (a micro thermal actuator) along a recording surface of the magnetic disk during rotation at a predetermined revolving speed. A flying height of the head for the gliding test is determined according to a revolving speed of the disk. When the flying height of the head for gliding test is determined according to the revolving speed at the certification test, the head for the gliding test is adjusted to a desired height by adjusting a variation of the heat distortion utilization mechanism disposed on the head for the gliding test. The gliding and certification inspections can be performed at the same time. ## Claims ### Claim 1 An inspection method of a magnetic disk, performing a gliding test and a certification test at the same time by simultaneously moving a head for the certification test and a head for the gliding test with a heat distortion utilization mechanism along a recording surface of the magnetic disk during a rotation of the magnetic disk at a predetermined revolving speed, wherein the heat distortion utilization mechanism to adjust a distance between the head for the gliding test and the recording surface of the magnetic disk according to an applied power. ### Claim 2 (depends on 1) The inspection method of the magnetic disk as claimed in claim 1, wherein a movement in a radial direction of the head for the gliding test precedes the head for the certification test in order to prevent the head for the gliding test and the head for the certification test from having a same radius and the certification test is interrupted when a projection of a bad disk is detected by the head for the gliding test. ### Claim 3 (depends on 1) The inspection method of the magnetic disk as claimed in claim 1, wherein the heat distortion utilization mechanism comprises a micro thermal actuator and the gliding test is performed by adjusting the distance which is a flying height between the head for the gliding test and the recording surface of the magnetic disk, wherein the applied power supplied to the micro thermal actuator. ### Claim 4 (depends on 2) The inspection method of the magnetic disk as claimed in claim 2, wherein the heat distortion utilization mechanism comprises a micro thermal actuator and the gliding test is performed by adjusting the distance which is a flying height between the head for the gliding test and the recording surface of the magnetic disk, wherein the applied power supplied to the micro thermal actuator. ### Claim 5 An inspection apparatus of a magnetic disk, comprising: a spindle means to rotate the magnetic disk in a mounting condition; a first head moving means to move a head for a gliding test with a heat distortion utilization mechanism along a recording surface of the magnetic disk mounted on the spindle; a second head moving means to move a head for a certification test along the recording surface of the magnetic disk mounted on the spindle; and a control means to simultaneously move the head for the gliding test and the head for the certification test along the recording surface of the magnetic disk by the first and the second head moving means, and to control the gliding test and the certification test to perform at the same time, wherein the heat distortion utilization mechanism to adjust a distance between the head for the gliding test and the recording surface of the magnetic disk according to an applied power. ### Claim 6 (depends on 5) The inspection apparatus of the magnetic disk as claimed in claim 5, wherein a movement in a radial direction of the head for the gliding test precedes the head for the certification test by the control means in order to prevent the head for the gliding test and the head for the certification test from having a same radius and the certification test is interrupted when a projection of a bad disk is detected by the head for the gliding test. ### Claim 7 (depends on 5) The inspection apparatus of the magnetic disk as claimed in claim 5, wherein the heat distortion utilization mechanism comprises a micro thermal actuator and the gliding test is performed by adjusting the distance which is a flying height between the head for the gliding test and the recording surface of the magnetic disk, wherein the applied power supplied to the micro thermal actuator. ### Claim 8 (depends on 6) The inspection apparatus of the magnetic disk as claimed in claim 6, wherein the heat distortion utilization mechanism comprises a micro thermal actuator and the gliding test is performed by adjusting the distance which is a flying height between the head for the gliding test and the recording surface of the magnetic disk, wherein the applied power supplied to the micro thermal actuator.