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Abstract
Lateral tape motion (LTM) is the motion of a tape perpendicular to the tape transport direction. It is a problem in magnetic tape recording technology that limits the track density on a tape. To reduce LTM, it is important to characterize the main sources of LTM in tape transports. In this dissertation, the effect of tape edge contact as well as tape tension transients on LTM is investigated. An optical non-contact tension sensor is developed and a correlation between LTM and tension transients is observed. Additionally, a method based on acoustic emission is established to measure tape edge contact. Tape edge contact is observed to cause high frequency LTM, and the magnitude of the impact is shown to be function of the tape pack size.
The dynamics of a tape as it moves over a cylindrical guide are studied theoretically and validated experimentally. Good agreement between theory and experiments is observed. In the experimental analysis, the tape/guide friction coefficient is observed to be function of different operating and design parameters. A model for the friction coefficient between a tape and a cylindrical guide is presented and evaluated with experimental data.
Finally, the use of laser surface texturing (LST) for improved tape guiding is proposed and investigated both experimentally and numerically. LST guides are observed to create an air bearing at low tape speeds and thus reduce the transition speed between boundary lubrication and full fluid lubrication. Additionally, the design of a dual stage actuator tape head for increased bandwidth track-following is introduced, as a means to enable increased track density on a tape for future high performance tape drives.
