Abstract: A rotary actuator disk drive uses substantially identical dual-element inductive write/magnetoresistive read transducers for both the top and bottom disk surfaces. There is no requirement that the read elements be mechanically offset from the write elements, as is typically the case in rotary actuator disk drives due to the head-to-track skew caused by the inherent nonlinear path of the heads across the data tracks. The transducers are supported on the trailing ends of the head carriers in such a manner that the geometric centers of the read and write elements are aligned without any mechanical offset. Sense currents of opposite polarity are provided to the magnetoresisitve read elements adjacent the top and bottom disk surfaces to shift the magnetic centers of the top and bottom read elements in opposite directions relative to their geometric centers.

Abstract: A method and apparatus for measuring the flying height of a slider supporting a magnetic transducer in-situ in a direct manner in an operational magnetic disk storage system. The method and apparatus produce relative motion between the magnetic transducer and a magnetic recording medium at a first velocity so that the resulting air bearing positions the magnetic transducer slider at a first flying height from the magnetic medium. A single signal of constant periodicity is written over a predetermined area of the recording medium by the magnetic transducer, and a readback signal is sensed from the predetermined area of the recording medium to produce a first signal. The flying height of the magnetic transducer slider is lowered to substantially zero, and a readback signal is sensed at the lowered flying height to produce a second signal. The first flying height is then calculated as the ratio, expressed in decibels, of the first and second signals times the wavelength divided by a constant.

Abstract: A propagation track for use in contiguous disk bubble devices consists of a plurality of spaced dovetail shaped elements which are connected at one end thereof by a track portion which faces in the direction of and is substantially perpendicular to the (1,1,2) axis. The first, third and fifth sides of the dovetail structure are elongated and also face in the direction of and are substantially perpendicular to the (1,1,2) axis. The remaining sides of the dovetail structure have different orientations, the second side facing in the direction of and being substantially perpendicular to the (2,1,1) axis, and the fourth side facing in the direction of and being substantially perpendicular to the (1,2,1) axis. The orientation of the two cusps formed by the first and second sides and the fourth and fifth sides is such that the lines bisecting and pointing toward the cusps are substantially parallel to the (1,2,1) and (2,1,1) axes, respectively.

Abstract: A propagation pattern for contiguous disk bubble devices consists of a plurality of parallel propagation tracks in which each propagation track is asymmetric. Adjacent propagation tracks are positioned so that the cusps that face each other are aligned therewith. The region between adjacent tracks forms two subregions which are mirror images of each other when the region is bisected by a longitudinal midplane.