Multimodule tape head assembly and measurement

The appropriate tape wrap on individual cylindrical modules achieves the he ad-tape spacing requirements of a multimodule tape head contour. High linea r recording densities in high-performance tape drives require contour desig ns that reduce tape wrap tolerance. High track densities lead to reduced el ement-to-element spacing in the direction of tape motion further reducing t he tolerance on desired tape wrap. The achievable tape wrap is a function o f the cylindrical profile, which is characterized by the radius and centerl ine location. Subsequently, tolerances and measurement of the cylindrical p rofile and the precision of the multimodule assembly process become critica l. A geometrical analysis of the relationship between the tolerance in the multimodule assembly and that of the cylindrical profile is presented. Such analysis is used to compare different techniques for multimodule assembly. Laser triangulation and multipoint interferometer systems are presented to simply, accurately, cheaply, and quickly measure cylindrical profiles.