Abstract
Runout (dynamic deflection) of both a Co-Cr/permalloy flexible A disk and a commercialized particulate flexible B disk of 3.5'' diameter was studied using a disk drive with two pairs of two pads arranged in series to the disk rotating direction, and a photometric positioning sensor in place of a small sized head of the single pole type. In the disk drive, the radial position on the disk was varied between 30 and 37 mm at disk revolution rates ranging from 400 to 1200 rpm, to evaluate the effect of the pads' configuration on runout characteristics. Runout of A disk was controlled between15 and 30μm, while runout of B disk was over 60μm and almost unchanged. Stable read/write characteristics of A disk were observed in the high density region of 70 kfci under 1 gf head-pressure and runout of around 20 μm.
