Heng Gong

US Patent:

6943993, Sep 13, 2005

Filed:

Feb 11, 2003

Appl. No.:

10/364799

Inventors:

Thomas Young Chang - Menlo Park CA, US
Yingjian Chen - Fremont CA, US
Jing Zhang - San Jose CA, US
Heng Gong - Layton UT, US

Assignee:

Western Digital (Fremont), Inc. - Lake Forest CA

International Classification:

G11B005/39

US Classification:

360319

Abstract:

Side shield structures magnetically shielding a read sensor to block side reading of tracks on a magnetic media. The read heads include bottom and top magnetic shield layers, a read sensor or magnetically sensitive element between the bottom and top magnetic shield layers, and a side shield assembly formed of magnetically shielding material positioned between the bottom and top magnetic shield layers and adjacent at least a portion of the read sensor. In current-in-plane embodiments, the side shield assembly includes a pair of side shields of magnetically shielding material adjacent a lower portion of the read sensor formed on a lower read gap. In current-perpendicular-to-plane embodiments, the side shield assembly includes a pair of side shields extending from the bottom magnetic shield adjacent lower sides of the read sensor and/or a pair of side shields extending from the top magnetic shield adjacent upper sides of the read sensor.

US Patent:

7616398, Nov 10, 2009

Filed:

Nov 9, 2007

Appl. No.:

11/983474

Inventors:

Heng Gong - San Jose CA, US
Mike X. Wang - San Jose CA, US
Jing Zhang - San Jose CA, US

Assignee:

Hitachi Global Storage Technologies Netherlands B.V. - Amsterdam

International Classification:

G11B 5/60

US Classification:

360 75

Abstract:

A method for calibrating a fly height adjustment device comprises flying a magnetic transducer coupled with a head gimbal assembly at a fly height from a magnetic recording data track. The magnetic transducer is coupled with a fly height adjustment device. Read-back signal amplitude is read from the magnetic recording data track with the magnetic transducer. The fly height is decreased with the fly height adjustment device. A linear fly height prediction is generated from the read-back signal amplitude and from power delivered to the fly height adjustment device as the fly height is decreased. The power delivered to the fly height adjustment device is compared with a difference between the linear fly height prediction and an implied fly height from the read-back signal amplitude, thereby calibrating the fly height adjustment device.

US Patent:

8174779, May 8, 2012

Filed:

Oct 31, 2006

Appl. No.:

11/591080

Inventors:

Terry Farren - Fremont CA, US
Heng Gong - San Jose CA, US
Yong Shen - Saratoga CA, US
Jing Zhang - San Jose CA, US

Assignee:

Hitachi Global Storage Technologies, Netherlands B.V. - Amsterdam

International Classification:

G11B 27/36

US Classification:

360 31

Abstract:

One embodiment in accordance with the invention is a method that comprises testing a first number of physical devices using a first test sequence that comprises an item. A second number of physical devices are tested using a second test sequence. It is noted that the second test sequence comprises the item of the first test and a second item.