Abstract: A method of analyzing defects in a magnetic thin film is provided. A magnetic field is applied to the magnetic thin film. The magnetization of the magnetic thin film is measured over a range of different field strengths. A value representative of a magnetic hardness coefficient is calculated for the magnetic thin film from the magnetizations measured. The calculated value is compared with a reference value. Defect information is determined in dependence upon the comparison made.
Type:
Grant
Filed:
August 20, 1999
Date of Patent:
March 13, 2001
Assignee:
Data Storage Institute
Inventors:
Jian-Ping Wang, Lea Peng Tan, Thomas Yun Fook Liew
Abstract: An electric spindle motor has a base assembly (19) and a hollow notatable hub (16) housing a motor. The hub (16) is mounted for rotation about an axis and a stator (12) is mounted on the base assembly (19) inside the hub (16). A liquid filled journal bearing (11, 21) acts between the base assembly (19) and the hub (16) to provide radial support of the hub (16). A gas filled thrust bearing (26, 27, 35) also acts between the hub (16) and base assembly (19) to provide at least axial support of the hub (16).
Type:
Grant
Filed:
May 18, 1999
Date of Patent:
February 1, 2000
Assignee:
Data Storage Institute
Inventors:
Zhejie Liu, Mohammed Abdul Jabbar, Qide Zhang, Teck Seng Low, Shixin Chen, Yuen Ann Mah
Abstract: An electric spindle motor has a base assembly (19) and a hollow notatable hub (16) housing a motor. The hub (16) is mounted for rotation about an axis and a stator (12) is mounted on the base assembly (19) inside the hub (16). A liquid filled journal bearing (11,21) acts between the base assembly (19) and the hub (16) to provide radial support of the hub (16). A gas filled thrust bearing (26, 27, 35) also acts between the hub (16) and base assembly (19) to provide at least axial support of the hub (16).
Type:
Grant
Filed:
July 3, 1997
Date of Patent:
October 19, 1999
Assignee:
Data Storage Institute
Inventors:
Zhejie Liu, M.A. Jabbar, Qide Zhang, Teck Seng Low, Shixin Chen, Yuen Ann Mah