Browse Prior Art Database

Surface Roughness Measurement

IP.com Disclosure Number: IPCOM000045753D
Original Publication Date: 1983-Apr-01
Included in the Prior Art Database: 2005-Feb-07
Document File: 2 page(s) / 39K

Publishing Venue

IBM

Related People

Alstad, KL: AUTHOR [+2]

Abstract

Immediate, on-line measurement of the surface roughness of flexible magnetic recording media is provided, during manufacture of the media, by the use of optical principles and data processing/image analysis techniques.

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Surface Roughness Measurement

Immediate, on-line measurement of the surface roughness of flexible magnetic recording media is provided, during manufacture of the media, by the use of optical principles and data processing/image analysis techniques.

A dry web of magnetic recording medium 10 moves left to right at a final stage of its manufacture. Long-radius glass lens 11 is pressed against the medium (whose roughness has been exaggerated), and the medium's roughness holds the lens at an average spacing to the medium due to the medium's asperities.

Flash-lamp device 12 momentarily illuminates the medium by way of semitransparent mirror 13. The resulting interference rings are viewed by video camera 14, through monochromatic filter 15 and microscope lens 16.

The analog electrical signal (video) generated by camera 14 is displayed on monitor 17, and is also digitized by video digitizer 18.

Microprocessor 19 analyzes the digitized signal and provides both a visual display 20 and a printout 21 of the average spacing of the underside of lens 11 to medium 10.

The two outputs 20 and 21 provide a measure of the medium's surface roughness, deviation from a standard roughness, etc. These measurements can be retained for future reference, as service data on a particular batch of media is later received.

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