Browse Prior Art Database

Magnetic Recording Media Testing

IP.com Disclosure Number: IPCOM000047266D
Original Publication Date: 1983-Oct-01
Included in the Prior Art Database: 2005-Feb-07
Document File: 2 page(s) / 51K

Publishing Venue

IBM

Related People

Hu, PY: AUTHOR [+3]

Abstract

A method is disclosed for testing a wide web of magnetic recording media, as it is being manufactured, and preferably just after calendaring, by the use of a spiral-scanning, read-after-write magnetic transducer. The resultant signal from the transducer is indicative of the integrity of the media coating and manufacturing process. Fig. 1 shows a portion of a media manufacturing line having a 24-inch wide web of flexible magnetic recording media 10 which moves from left to right through calendar device 11, at a speed of about 250 feet per minute. The above-mentioned scanner is shown at 12. Fig. 2 shows scanner 12 in greater detail. This scanner is of the type disclosed in U.S. Patent 4,112,472. The scanner includes a rotor 13 which supports the read/write heads.

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Magnetic Recording Media Testing

A method is disclosed for testing a wide web of magnetic recording media, as it is being manufactured, and preferably just after calendaring, by the use of a spiral-scanning, read-after-write magnetic transducer. The resultant signal from the transducer is indicative of the integrity of the media coating and manufacturing process. Fig. 1 shows a portion of a media manufacturing line having a 24-inch wide web of flexible magnetic recording media 10 which moves from left to right through calendar device 11, at a speed of about 250 feet per minute. The above-mentioned scanner is shown at 12. Fig. 2 shows scanner 12 in greater detail. This scanner is of the type disclosed in U.S. Patent 4,112,472. The scanner includes a rotor 13 which supports the read/write heads. Rotor 13 is supported by housing 14, and is driven at a speed of about 1,000 rpm by motor
15. Web 10 is supported by a grooved backing plate 16 as it is transduced by the heads. The rotor-to-web spacing is controlled by lead screw adjustment 17. Fig. 3 shows the tapered or wedge-shaped underside 20 of rotor 13, and the write head 18 and read head 19 which are mounted on the raised apex of surface 20. The enlarged view of Fig. 4 shows the detail of stationary backing plate 16 which supports web 10 as it is transduced by heads 18, 19. Backing plate 16 includes a circular groove 21 which coincides with the circular track of heads 18, 19. As a result, a hydrodynamic air bearing...