Jeffrey W Liu

US Patent:

6339569, Jan 15, 2002

Filed:

Apr 9, 1999

Appl. No.:

09/289271

Inventors:

Jeffrey F. Liu - San Jose CA
Francis K. King - San Jose CA

Assignee:

Dcard, Inc. - Milpitas CA

International Classification:

G11B 700

US Classification:

369 4727, 369 533

Abstract:

This invention discloses an optical servo writer. The optical servo writer includes an optical pickup head for rotationally moving over and writing servo data in an optical flat data-storage medium. The optical servo writer further includes a clock head for providing clock signals to the pickup head and to write clock signals in the clock disk. The optical servo writer further includes a control circuit for controlling The optical pickup head for writing the servo data on The optical flat data-storage medium. The optical servo writer further includes a servo pattern layout circuit for controlling The optical pickup head for writing the servo data on The optical flat data-storage medium with predefined servo patterns. The optical servo writer further includes a derived index control circuit for deriving indices from a fixed index provided on The optical flat data-storage medium. The optical servo writer further includes a fixed index and clock track circuit for providing a fix index and a clock signal for controlling The optical pickup head for writing the servo data on The optical flat data-storage medium.

US Patent:

6417980, Jul 9, 2002

Filed:

Apr 9, 1999

Appl. No.:

09/289427

Inventors:

Jeffrey F. Liu - San Jose CA
Francis K. King - San Jose CA

Assignee:

Dcard, Inc. - Milpitas CA

International Classification:

G11B 2102

US Classification:

360 75, 360 2, 360101

Abstract:

This invention discloses a magnetic servo writer. The magnetic servo writer includes a magnetic pickup head for rotationally moving over and writing servo data in a magnetic flat data-storage medium. The magnetic servo writer further includes a clock head for providing clock signals to the pickup head and to write clock signals in the clock disk. The magnetic servo writer further includes a control circuit for controlling the magnetic pickup head for writing the servo data on the magnetic flat data-storage medium. The magnetic servo writer further includes a servo pattern layout circuit for controlling the magnetic pickup head for writing the servo data on the magnetic flat data-storage medium with predefined servo patterns. The magnetic servo writer further includes a derived index control circuit for deriving indices from a fixed index provided on the magnetic flat data-storage medium. The magnetic servo writer further includes a fixed index and clock track circuit for providing a fix index and a clock signal for controlling the magnetic pickup head for writing the servo data on the magnetic flat data-storage medium.

US Patent:

6502755, Jan 7, 2003

Filed:

Apr 9, 1999

Appl. No.:

09/289447

Inventors:

Jeffrey F. Liu - San Jose CA
Francis K. King - San Jose CA

Assignee:

DCARD, Inc. - Milpitas CA

International Classification:

G06K 1900

US Classification:

235489, 235454, 235494, 369 16

Abstract:

The optical data-storage card includes an optical data-storage medium layer supported on the card. The data-storage medium layer includes a plurality of data storage tracks for storing data therein. Each of the tracks having at least an arc-segment wherein each of the data storage tracks being substantially parallel to a neighboring track.

US Patent:

6588671, Jul 8, 2003

Filed:

Aug 3, 2001

Appl. No.:

09/922572

Inventors:

Francis K. King - San Jose CA
Jeffrey Liu - San Jose CA

Assignee:

Dcard, Inc. - Milpitas CA

International Classification:

G06K 700

US Classification:

235486, 235475, 235485

Abstract:

This invention is a data storage system for accessing data stored in a data storage medium. The data storage system includes a motor-head assembly controlled to activate a vertical movement for loading and unloading at least a pickup head supported thereon to access the data medium in the data storage medium. For a specific data-storage system configuration, the motor-head assembly further includes a rotating motor for rotating the pickup head when the pickup head is loaded onto the data storage medium. In another system configuration, the data storage system implemented with a motor to move the data storage medium in at least one linear direction or for rotating the data storage medium. The motor-head assembly further includes a vertical-position locking hook for automatically pulling away the pickup head from the data storage media when the motor-head assembly is unloaded from the data storage medium. The vertical-position locking linkage further automatically unlock the pickup head in an unconstrained compliance state next to the data storage medium when the motor-head assembly is loaded to the data storage medium.

US Patent:

6728059, Apr 27, 2004

Filed:

Jul 8, 2002

Appl. No.:

10/191959

Inventors:

Jeffrey F. Liu - San Jose CA
Francis K. King - San Jose CA

Assignee:

Dcard, Inc. - Milpitas CA

International Classification:

G11B 2102

US Classification:

360 75, 360 2, 235487, 235493

Abstract:

This invention discloses a magnetic servo writer. The magnetic servo writer includes a magnetic pickup head for rotationally moving over and writing servo data in a magnetic flat data-storage medium. The magnetic servo writer further includes a clock head for providing clock signals to the pickup head and to write clock signals in the clock disk. The magnetic servo writer further includes a control circuit for controlling the magnetic pickup head for writing the servo data on the magnetic flat data-storage medium. The magnetic servo writer further includes a servo pattern layout circuit for controlling the magnetic pickup head for writing the servo data on the magnetic flat data-storage medium with predefined servo patterns. The magnetic servo writer further includes a derived index control circuit for deriving indices from a fixed index provided on the magnetic flat data-storage medium. The magnetic servo writer further includes a fixed index and clock track circuit for providing a fix index and a clock signal for controlling the magnetic pickup head for writing the servo data on the magnetic flat data-storage medium.

US Patent:

6775080, Aug 10, 2004

Filed:

Jan 29, 2001

Appl. No.:

09/774200

Inventors:

Francis K. King - San Jose CA
Jeffrey F. Liu - San Jose CA

Assignee:

DCARD, Inc. - Milpitas CA

International Classification:

G11B 509

US Classification:

360 48, 360 2, 360 75, 235493

Abstract:

This invention discloses a data access system for access data stored on a flat medium. The data access system includes a pickup head rotating over the flat medium. The data access system further includes at least one stepping motor for discretely moving the flat medium substantially along at least one lateral direction perpendicular to a rotational axis of the pickup head. The data access system further includes a closed loop control mechanism for controlling the stepping motor for allowing the pickup head to read data from a servo segment on the flat medium. The controller further includes an open loop control mechanism for rotating the pickup head for reading data from and writing data to a data segment disposed right next to the servo segment on the flat medium.

US Patent:

6934098, Aug 23, 2005

Filed:

Oct 1, 2001

Appl. No.:

09/969288

Inventors:

Francis K. King - San Jose CA, US
Jeffrey F. Liu - San Jose CA, US

Assignee:

DCARD, Inc. - Mulpitas CA

International Classification:

G11B025/04

US Classification:

360 2, 360 48, 360101

Abstract:

This invention discloses a flat data storage medium that includes a plurality of substantially parallel data arc-segments. The data arcs further include at least one full circle data track provided for obtaining a measurement of an average amplitude of data signals over the full circle data track for calibrating a pickup head implemented for reading data from the data arc-segments. This invention further discloses a data storage system for accessing data stored in a data storage medium. The data storage system includes dynamic head loading/unloading system that includes a handle for pushing a linkage connected to the handle for loading and unloading the data storage medium to an engaged and disengaged positions relative to a pickup head for accessing data disposed on the data storage medium. The dynamic head loading/unloading system further includes a locking mechanism for automatically locking the data storage medium inside the data storage system when the linkage is disposed at an engaged-position. The dynamic head loading/unloading system further includes a data-storage medium orientation-selection for cooperating and adapting the data storage medium inside the data storage system only when the data storage medium is inserted into the data storage system in a predefined orientation.

US Patent:

7185814, Mar 6, 2007

Filed:

Feb 17, 2004

Appl. No.:

10/779961

Inventors:

Jeffrey Liu - San Jose CA, US
Francis K. King - San Jose CA, US

Assignee:

Dcard, Inc. - Milpitas CA

International Classification:

G06K 7/10
G06K 7/14
G06K 19/00
G06K 5/00
G11B 7/20

US Classification:

235454, 235487, 235380, 369 97, 428 644

Abstract:

This invention discloses an optical memory strip and a data card that has at least an optical memory strip as a cutoff piece bonding and attaching to the data card for storing data accessible with an optical read/write head. The data card can further includes at least a magnetic data track for storing data accessible with a magnetic data read/write head. In another data card of this invention, it further includes a semiconductor data storage card for storing data that is accessible by using a semiconductor chip data read/write device.