High speed flexible disk - head interface

Progress toward the use of high speed flexible disks in recording systems has been made possible by a better understanding of stabilization requirements. Benson and Bogy [1], and Greenberg [2] have described the overall response to a localized load on a flexible disk. Greenberg describes the head/disk interface with an expression that uses Reynolds equation for loading. This study examines the flying height behavior between a high speed flexible disk and a spherical head using white light interferometry. Geometric parameters determining optimum flying characteristics are discussed, and stable, relatively uniform air bearing spacings in the sub-micron region are described at a surface speed of 40 m/sec. Correlation is established with a computer model which couples the solution of the Reynolds equation for the air bearing with a simplified treatment of a localized region of the disk. This portion of the disk is considered as a membrane on an elastic foundation. Steady state tension and elasticity parameters are used to model rotational stresses and axial compliance.