Apparatus and method for dynamic fly height adjustment

#1. The Field of the Invention

#The invention relates to physical asperity testing of disk drive systems. More specifically, the present invention relates to manners of improving disk drive physical asperity testing by exact calibration of disk drive testing systems.

#2. The Relevant Art

#In order that the manner in which the advantages and objects of the invention are obtained will be readily understood, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered to be limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:

#FIG. 1 is a schematic block diagram illustrating one embodiment of a physical asperity test of the present invention.

#FIG. 2a is a schematic block diagram illustrating fly height.

#Referring to FIG. 3, shown therein is a simplified schematic block diagram illustrating the concept of a dynamic fly height adjustment device 300 of the present invention. In one embodiment, the fly height adjustment device 300 comprises a physical asperity sensor (PAS) flying head 302 attached to a head gimble assembly 303 through a gimbal structure, a mounting plate 304, a pivot control device 306, a semi-spherical pivoting device 308, and a load ring 310. The PAS head 302 rides on the head gimble assembly, or HGA 303 which is shown coupled to the semi-spherical pivoting device 308. The semi-spherical pivoting device 308 is attached to the pivot control device 306 through a similarly shaped aperture in the mounting plate 304. The semi-spherical pivoting device 308 allows for fine calibrations of the PAS head 302.

#In one embodiment, the pivot control device 306 is utilized in a manner substantially equivalent to that of a joystick. With reference to FIG. 3, movement of the pivot control device 306 to the right raises the PAS head 302, while, movement of the pivot control device 306 to the left lowers the PAS head 302. Movement of the pivot control device 306 in a direction into and out of the page alters the roll of the PAS head 302, as described with reference to FIG. 2b.

#FIG. 4 illustrates one embodiment of a PAS portion 400 of a calibration device of the present invention. In the depicted embodiment, the PAS calibration device 400 is modular and removable from the glide-testing device 600 of FIG. 6. As depicted, the PAS portion 400 comprises a first mounting plate 402, a pivot control device 404, a load ring 406, a first sphere 408, a second sphere 410, a second mounting plate 412, and a load/unload device 414. Preferably, the pivot control device 404 operates in a manner substantially equivalent to that of the pivot control device 306 of FIG. 3. The pivot control device is manipulated in a manner that will be described in greater detail below with reference to FIG. 6.