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US006650509B2
(12) United States Patent ao) Patent No.: us 6,650,509 B2
Gill (45) Date of Patent: Nov. 18,2003
(54) DUAL SPIN VALVE SENSOR WITH AP PINNED LAYERS
(75) Inventor: Hardayal Singh Gill, Palo Alto, CA (US)
(73) Assignee: Hitachi Global Storage Technologies Netherlands B.V., Amsterdam (NL)
( * ) Notice: Subject to any disclaimer, the term of this patent is extended or adjusted under 35 U.S.C. 154(b) by 271 days.
(21) Appl. No.: 09/813,609
(22) Filed: Mar. 20, 2001
(65) Prior Publication Data
US 2002/0159199 Al Oct. 31, 2002
(51) Int. CI.7 G11B 5/127; G11B 5/33;
G11B 5/39
(52) U.S. CI 360/314; 360/324.11; 360/324.12
(58) Field of Search 360/324.11, 324.12,
360/313, 317, 324, 324.1, 110, 314
(56) References Cited
U.S. PATENT DOCUMENTS
5,301,079 A 4/1994 Cain et al 360/324
5,442,508 A 8/1995 Smith 360/314
5,583,725 A 12/1996 Coffey et al 360/324.11
5,627,703 A 5/1997 Smith 360/314
5,677,625 A 10/1997 Dieny 324/252
5,701,222 A 12/1997 Gill et al 360/314
5,705,973 A 1/1998 Yuan et al 338/32 R
5,768,069 A 6/1998 Mauri 360/314
5,825,595 A 10/1998 Gill 360/314
5,880,913 A 3/1999 Gill 360/324.11
5,920,446 A 7/1999 Gill 360/324
6,175,476 Bl * 1/2001 Huai et al 360/324.11
6,317,297 Bl * 11/2001 Tong et al 360/314
6,449,134 Bl * 9/2002 Beach et al 360/324.12
2001/0009063 Al * 7/2001 Saito et al 29/603.08
FOREIGN PATENT DOCUMENTS
JP 11103102 4/1999
JP 11191207 7/1999
JP 2000-349364 A * 12/2000
OTHER PUBLICATIONS
IEEE Transactions on Magnetics, 35/2, Mar. 1999 "Spin Valve and Dual Spin Valve Heads.."
* cited by examiner
Primary Examiner—-Julie Anne Watko
(74) Attorney, Agent, or Firm—Ervin F. Johnston
