Study of magnitude and component frequency variation of lateral tape motion across an unsupported tape region

Abstract

Magnetic data tape is one of the most costeffective means of large scale information storage, and has the capacity to remain so in the future. Many challenges must be met in order to improve the storage density of magnetic tape systems and keep up with customer demands. One of these challenges is to minimize the relative motion between the read/write elements in the tape drive and the data tracks on the tape, also known as lateral tape motion (LTM). Modern closed-loop servo-based track following techniques are able to compensate for a large portion of the LTM events experienced, but care must still be taken in design of both the tape drive and tape media in order to minimize the negative effects of LTM. This paper details a study in which a new delay-integration method is applied to LTM measurement. The advantages and disadvantages of the method are discussed, and a comparison is made with previous LTM measurement methods. The delay-integration method is then applied to measure the change in LTM amplitude along an unsupported region of tape for several different tape samples. As many tape systems place the read/write head in the center of an unguided region, information about the behavior of tape in this situation could be used to minimize LTM, allowing for smaller data tracks and increased storage density.