The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 02, 1980
Filed:
Jul. 10, 1979
Robert W Erickson, Jr, Pacific Palisades, CA (US);
G Randall Stevens, Inglewood, CA (US);
Per Sci, Inc., Los Angeles, CA (US);
Abstract
A disk drive for one or more spinning disks has a voice coil motor, driving the transducer carriage and controlled by two feedback loops, respectively, for hold and seek modes and enabled by a microcomputer which is additionally inserted into the seek mode feedback loop. The microcomputer receives step pulses from a controller host as well as detent pulses through a path of that seek loop; the pulses serve as interrupts and the microcomputer selects digital speed signals on the basis of step and detect pulse counts. An a/d converter inserts that signal as command into the seek loop. The microcomputer performs basically a continuous loop type of program pursuant to which command (select) lines from the host are interrogated and the hold mode is maintained until, for example, one or more step pulses interrupt this program loop to command the drive to move the carriage to another track; the microcomputer then shifts the drive to the seek mode, which is maintained by the continuous loop until the carriage has arrived at the new position. Special subroutines cause the drive to center on a zero track when externally or internally commanded. A variety of diagnostic tests can be performed.