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:
Sep. 19, 1995
Filed:
Jul. 19, 1994
Hamid Baheri, Sherman Oaks, CA (US);
Peter Campbell, Los Angeles, CA (US);
Daniel L Griffith, Ventura, CA (US);
Jefferson H Harman, Thousand Oaks, CA (US);
Wangtek, Inc., Simi Valley, CA (US);
Abstract
A magnetic recording head positioning system includes a Terfenol-D magnetostrictive rod prestressed by a lever arm to operate in a linear range to microposition the magnetic recording head in accordance with an electromagnetic field. The mechanical advantage of the lever arm amplifies changes in the magnetostrictive rod to position the head. The varying electromagnetic field is applied to the rod by a coil in response to a position error signal produced from servo data tracks on the magnetic tape. A permanent magnet system biases the magnetostrictive element with a DC field so that varying the field provides bi-directional motion of the magnetic recording head. The DC field also reduces coil current and size requirements. The position signal is filtered so that changes in length of the magnetostrictive rod provide fast, fine positioning of the head while a stepper motor and lead screw subassembly system provide slow, coarse positioning of the magnetic recording head by moving the magnetostrictive element assembly in an open loop and/or closed or servo loop mode.