Wai Yiu Leung

US Patent:

6357095, Mar 19, 2002

Filed:

Jul 23, 1999

Appl. No.:

09/360477

Inventors:

Shanlin Duan - Fremont CA
Wei-Ming Lee - Pleasanton CA
Wai C. Leung - San Jose CA

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

B24B 3900

US Classification:

29 9001, 451290, 451317

Abstract:

The burnishing head for hard disk processing includes a solid body having generally rectangular surfaces, including an upper surface, a burnishing pad surface, a front surface, a rear surface and two side surfaces. A plurality of burnishing pads are disposed upon the burnishing pad surface. The pads are shaped such that each pad has a burnishing edge that is generally parallel to said front surface and therefore orthogonal to the direction of media travel. The burnishing pads are preferably configured such that one frontward leading pad is centrally disposed proximate the front surface of the head, followed by two middle pads that are disposed in a spaced apart relationship. A single centrally disposed rear middle pad is formed behind the two middle pads, and two rear pads are disposed in a spaced apart relationship at the rear surface of the head. In the preferred embodiment the pads are generally triangular in shape and the outer surface of the leading and rearward pads is tapered. The method for manufacturing the burnishing head, includes the steps of making a series of parallel cuts in a surface of a solid body of material.

US Patent:

6407891, Jun 18, 2002

Filed:

May 24, 1999

Appl. No.:

09/317808

Inventors:

Thomas Young Chang - San Jose CA
Shanlin Duan - Fremont CA
Terence Tin-Lok Lam - San Jose CA
Wai C. Leung - San Jose CA

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G11B 539

US Classification:

360317, 360319

Abstract:

The present invention is a read/write head for writing information to magnetic media and reading information from magnetic media. It includes a write head for writing information onto magnetic media, a read head for reading information from the magnetic media, and an electrical circuit element that is disposed proximate the read head that functions to generate an electromagnetic field at the read head that is generally oppositely directed to the electromagnetic field generated by the write head. The method for operating the read/write head in a hard disk drive, includes the steps of writing data onto a hard disk, while simultaneously generating an electromagnetic field at the read head that is directed oppositely to the electromagnetic field generated by the write head.

US Patent:

6477008, Nov 5, 2002

Filed:

May 24, 1999

Appl. No.:

09/317668

Inventors:

Thomas Young Chang - San Jose CA
Shanlin Duan - Fremont CA
Terence Tin-Lok Lam - San Jose CA
Wai C. Leung - San Jose CA

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G11B 5115

US Classification:

360128, 360126, 360317

Abstract:

The present invention is a read/write head for writing information to magnetic media and reading information from magnetic media. It includes a write head element for writing information onto magnetic media, a read head element for reading information from the magnetic media, and an electromagnetic field shield element that is disposed between the write head element and the read head element. The shield functions to shield the read head from electromagnetic field energy created by the write head element. An enhanced second embodiment includes an electrical circuit element that is disposed proximate the read head element that functions to generate an electromagnetic field at the read head element that is generally oppositely directed to the electromagnetic field generated by the write head element to reduce the total electromagnetic field that the read head element is exposed to during a writing operation. The method for operating the read/write head in a hard disk drive, includes the steps of writing data onto a hard disk and reading data from the hard disk simultaneously with the data writing. This is accomplished by shielding the read head from the electromagnetic field energy generated during the data writing by utilizing the electromagnetic field shield element that is disposed between the write head element and the said read head element.

US Patent:

6614519, Sep 2, 2003

Filed:

Oct 25, 2000

Appl. No.:

09/696864

Inventors:

Milton Russell Latta - San Jose CA
Wai Cheung Leung - San Jose CA
Bob C. Robinson - Hollister CA
Timothy Carl Strand - San Jose CA
Andrew Ching Tam - Saratoga CA

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G01N 2188

US Classification:

3562372, 3562371

Abstract:

An inspection system using laser light directed at an off-axis parabolic mirror which focuses the beam on the surface being inspected and also serves as the collector for scattered and specular light returned from the surface is described. Specular and scattered light returned from the surface onto the parabolic mirror is divided into appropriate fields and directed onto detectors. In the preferred embodiment a polarized laser is used in conjunction with a polarizing beam splitter and a quarter-wave plate to route the reflected beam to a detector while allowing the original beam to be directed through the same optics. The parabolic mirror and selected additional components may be commonly mounted on a translatable stage which is moved along a radius of the disk when the optical inspection is being performed. Other components of the system such as the laser can remain in a fixed position. The system of the invention can be used to inspect one or both planar surfaces of the disk by providing duplication of selected components appropriately oriented with respect to the second surface.

US Patent:

6624884, Sep 23, 2003

Filed:

Apr 28, 1997

Appl. No.:

08/840351

Inventors:

Wayne Isami Imaino - San Jose CA
Anthony Juliana, Jr. - San Jose CA
Milton Russell Latta - San Jose CA
Charles H. Lee - San Jose CA
Wai Cheung Leung - San Jose CA
Hal J. Rosen - Los Gatos CA
Steven Meeks - San Jose CA

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G01N 2188

US Classification:

3562372

Abstract:

A laser based inspection tool (LIT) for inspecting planar surfaces is described. In a preferred embodiment the LIT can simultaneously inspect both planar surfaces of disks for use in disk drives. In an embodiment of the invention, light reflected from the surface at an angle slightly offset from perpendicular is routed through a telecentric lens to a detector which converts the intensity of the reflected beam into an analog signal. The analog signal is sampled and digitized to generate pixel data. A data acquisition system sequentially stores the pixel data in a buffer. A median filter and derivative analysis can be applied to the pixel data to detect deviations indicating defects. An optional calibration system periodically reflects the scanning beam back to a detector to form a reference signal for use in absolute reflectivity measurements.

US Patent:

6704435, Mar 9, 2004

Filed:

Apr 28, 1997

Appl. No.:

08/841214

Inventors:

Wayne Isami Imaino - San Jose CA
Anthony Juliana - San Jose CA
Milton Russell Latta - San Jose CA
Charles H. Lee - San Jose CA
Wai Cheung Leung - San Jose CA
Hal J. Rosen - Los Gatos CA
Steven Meeks - San Jose CA

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G06K 900

US Classification:

382108

Abstract:

A laser based inspection tool (LIT) for inspecting planar surfaces is described. In a preferred embodiment the LIT can simultaneously inspect both planar surfaces of disks for use in disk drives. In one embodiment of the invention, the incident beam is directed onto the surface to be inspected at an angle slightly offset from perpendicular so that the reflected beam is physically separated from the incident beam. The reflected beam is routed to a detector which converts the intensity of the reflected into an analog signal. The analog signal is sampled and digitized to generate pixel data stored in a buffer. Various analyses are performed on the data including calculating a rate of change in the pixel data. If the rate of change in the pixel data exceeds a selected threshold that indicates a possible defect if it occurs in the data area of the disk.

US Patent:

20050289639, Dec 29, 2005

Filed:

Jun 23, 2004

Appl. No.:

10/874778

Inventors:

Wai Leung - Houston TX, US

International Classification:

H04L009/00

US Classification:

726002000

Abstract:

The present invention provides an integrated method and system implemented on a plurality of computer systems in a network. The method is for securing and controlling access to digitized files utilized in the documentation management process. The method further comprises generating a project encryption key for an identified project having a plurality of project documents as well as controlling access to the project encryption key and the plurality of project documents of the identified project to authenticated users. Then, for a selected project document of an authenticated user, an encrypted digitized document is generated utilizing the project encryption key. For a selected project document of an authenticated user, an encrypted text from the selected encrypted graphic image is generated utilizing the project encryption key. For a selected project document of an authenticated user, an encrypted searchable PDF from the selected encrypted PDF is generated utilizing the project encryption key. For a selected project document of an authenticated user, coding instructions is performed on the encrypted digitized file utilizing the project encryption key. Coding instructions can be performed manually or programmatically. For a selected project document of an authenticated user, print (blowback) the encrypted PDF or image utilizing the project encryption key. In some embodiments, a project encryption key is not generated but accepted and stored within the system. Additionally, the system and method is adapted to handle the offsite or offshore coding process.

US Patent:

61176206, Sep 12, 2000

Filed:

Dec 4, 1998

Appl. No.:

9/205667

Inventors:

Wayne Isami Imaino - San Jose CA
Anthony Juliana - San Jose CA
Milton Russell Latta - San Jose CA
Charles H. Lee - San Jose CA
Wai Cheung Leung - San Jose CA
Hal J. Rosen - Los Gatos CA
James Hammond Brannon - Palo Alto CA

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G03C 516

US Classification:

430320

Abstract:

A method of making a calibration disk for a laser based inspection tool (LIT) for inspecting planar surfaces is described. The calibration disk has a plurality of overlapping bumps forming a circular ring with a width of one bump. The circular ring of bumps forms a feature of a known width and position on a disk which can be used to adjust one or more LIT's to yield calibrated results. The ring of overlapping bumps is preferably formed by rotating a disk substrate under a stationary pulsing laser beam.