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:
Mar. 20, 2012
Filed:
Feb. 23, 2009
John Thomas Contreras, Palo Alto, CA (US);
Yimin Hsu, Sunnyvale, CA (US);
Manfred Ernst Schabes, Saratoga, CA (US);
Xinzhi Xing, San Jose, CA (US);
John Thomas Contreras, Palo Alto, CA (US);
Yimin Hsu, Sunnyvale, CA (US);
Manfred Ernst Schabes, Saratoga, CA (US);
Xinzhi Xing, San Jose, CA (US);
Hitachi Global Storage Technologies Netherlands B.V, Amsterdam, NL;
Abstract
A perpendicular magnetic recording system has a write head with a main perpendicular write pole connected to a yoke with first and second electrical coils. The first coil is wrapped around the yoke on one side of the main pole, and the second coil is wrapped around the yoke on the other side of the main pole. The first end of each coil is connected to a respective terminal. The second ends of the two coils are connected together and connected to a common terminal. A lead-time circuit is connected between the common terminal and the first end of one of the coils. Immediately after the direction of write current is switched by the write driver, the lead-time circuit causes the current in one of the coils to lead the current in the other coil. The current displacement between the two coils creates a precession of the magnetic flux reversal, thereby reducing the switching time of the write head.