Dual very-high density magnetic head assembly with optical servo positioning for very high density floppy disk recording and high density format compatability

摘要

A disk system comprising an upper and lower head gimbal assembly, a coarse positioning servo system that includes a stepper motor for 135 TPI operation and a voice coil motor type servo for 1251 TPI operation that is driven by a optical servo system which locates optical track positioning information previously recorded on 3.5 inch microfloppies. The optical system focuses a spot of infrared light on the microfloppy which is channeled back to a detector. Each head gimbal includes a ceramic slider with two air bearing surfaces. A very high density magnetic core is positioned in one air bearing surface and high density magnetic core is located in the other air bearing surface. Both upper and lower sliders are such that the floppy disk media is pinched between them. The gaps of the magnetic cores are positioned within the leading edge half of their respective air bearing surfaces and take advantage of the tendency of the sliders to plow into the floppy disk media. The very high density and high density cores are offset differently from the centerline of the sliders to reduce crosstalk coupling between heads on opposite sides of the floppy disk media.