Patents by Inventor Keung Youn Cho

Keung Youn Cho has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20120317313
    Abstract: A disk device can include a controller configured to transmit first commands in response to second commands from a host, the first commands to assign at least one identification (ID) code to at least one of a plurality of storage areas in a storage device, the second commands including the at least one ID code; wherein the controller transfers data between the host and the storage device using the ID codes.
    Type: Application
    Filed: August 22, 2012
    Publication date: December 13, 2012
    Applicant: SEAGATE TECHNNOLOGY INTERNATIONAL
    Inventors: Jun-ho Jang, Keung-youn Cho
  • Patent number: 8266328
    Abstract: Provided are systems and methods to communicate data transfer of data between a disk device and an external storage device. A host can generate a control command to communicate with an external storage device, and a disk device to receive the control command from a host to identify and communicate with an external storage device when connected to the external storage device and to configure the external storage device by assigning an ID code to each storage area of the external storage device.
    Type: Grant
    Filed: February 2, 2011
    Date of Patent: September 11, 2012
    Assignee: Seagate Technology International, LLC
    Inventors: Jun-ho Jang, Keung-youn Cho
  • Publication number: 20110191501
    Abstract: Provided are systems and methods to communicate data transfer of data between a disk device and an external storage device. A host can generate a control command to communicate with an external storage device, and a disk device to receive the control command from a host to identify and communicate with an external storage device when connected to the external storage device and to configure the external storage device by assigning an ID code to each storage area of the external storage device.
    Type: Application
    Filed: February 2, 2011
    Publication date: August 4, 2011
    Applicant: Samsung Electronics Co., Ltd.
    Inventors: Jun-ho JANG, Keung-youn Cho
  • Patent number: 7876519
    Abstract: A method for erasing a disk of a hard disk drive. The method includes moving the hard disk drive adjacent to an erasure head that emanates a magnetic field. The magnetic field and moving hard disk drive cause a disk of the hard disk drive to spin under a Lorentz force created by the magnetic field and moving disk. The magnetic field is applied by the erasure head for a duration that causes erasure of the entire disk. The spindle motor is not activated during the entire process. Not activating the spindle motor eliminates any Faraday coupling from the erasure head into the motor.
    Type: Grant
    Filed: December 16, 2008
    Date of Patent: January 25, 2011
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Carl Xiaodong Che, Keung Youn Cho, Soo-Youl Hong, Shuo-Hao Chen
  • Patent number: 7869161
    Abstract: A perpendicular recording head for a hard disk drive. The head includes a non-magnetic backside shield that minimizes or eliminates the flow of backside flux through the head. The head can be fabricated by forming a non-magnetic backside shield layer on a main pole. Portions of the backside shield and main pole can be removed to form a tapered pole portion. A non-magnetic write-gap layer and write shield are then formed onto the backside shield and main pole.
    Type: Grant
    Filed: June 4, 2007
    Date of Patent: January 11, 2011
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Peng Luo, Keung Youn Cho, Shuyu Sun
  • Publication number: 20100149677
    Abstract: A method for erasing a disk of a hard disk drive. The method includes moving the hard disk drive adjacent to an erasure head that emanates a magnetic field. The magnetic field and moving hard disk drive cause a disk of the hard disk drive to spin under a Lorentz force created by the magnetic field and moving disk. The magnetic field is applied by the erasure head for a duration that causes erasure of the entire disk. The spindle motor is not activated during the entire process. Not activating the spindle motor eliminates any Faraday coupling from the erasure head into the motor.
    Type: Application
    Filed: December 16, 2008
    Publication date: June 17, 2010
    Applicant: Samsung Electronics Co., Ltd.
    Inventors: Carl Xiaodong Che, Keung Youn Cho, Soo-Youl Hong, Shuo-Hao Chen
  • Publication number: 20090151434
    Abstract: An Atomic Force Microscope (AFM) using a cantilevered probe containing a slider of a kind useable in a disk drive. The AFM may use a test surface similar to a disk surface in the disk drive and measure friction, lubricant depletion, and/or scratch test in the AFM to estimate the same under conditions experienced in the disk drive. The AFM may also include a Peltier plate thermally coupled to test object to maintain test surface at controlled test temperature. Refinements of the measurements are disclosed.
    Type: Application
    Filed: December 17, 2007
    Publication date: June 18, 2009
    Inventors: Dongman Kim, Michael Sullivan, Keung Youn Cho
  • Patent number: 7535667
    Abstract: A hard disk drive with a disk that has a servo field with an A servo burst and a B servo burst. The A servo burst has a trimmed erase band. The trimmed erase band can be created by offsetting the write head relative to a burst centerline to reduce the width of the erase band. For example, the write head can be moved toward a centerline of the A servo burst. The offset can be a function of write current and cylinder location of the disk. The offsets are selected so that the resultant burst profiles do not contain a flat minimum portion.
    Type: Grant
    Filed: June 4, 2007
    Date of Patent: May 19, 2009
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Peng Luo, Keung Youn Cho, Hao Ping Wen, Shuyu Sun
  • Publication number: 20080297938
    Abstract: A hard disk drive with a disk that has a servo field with an A servo burst and a B servo burst. The A servo burst has a trimmed erase band. The trimmed erase band can be created by offsetting the write head relative to a burst centerline to reduce the width of the erase band. For example, the write head can be moved toward a centerline of the A servo burst. The offset can be a function of write current and cylinder location of the disk. The offsets are selected so that the resultant burst profiles do not contain a flat minimum portion.
    Type: Application
    Filed: June 4, 2007
    Publication date: December 4, 2008
    Applicant: Samsung Electronics Co., Ltd.
    Inventors: Peng Luo, Keung Youn Cho, Hao Ping Wen, Shuyu Sun
  • Publication number: 20080297946
    Abstract: A perpendicular recording head for a hard disk drive. The head includes a non-magnetic backside shield that minimizes or eliminates the flow of backside flux through the head. The head can be fabricated by forming a non-magnetic backside shield layer on a main pole. Portions of the backside shield and main pole can be removed to form a tapered pole portion. A non-magnetic write-gap layer and write shield are then formed onto the backside shield and main pole.
    Type: Application
    Filed: June 4, 2007
    Publication date: December 4, 2008
    Applicant: Samsung Electronics Co., Ltd.
    Inventors: Peng Luo, Keung Youn Cho, Shuyu Sun
  • Patent number: 7414808
    Abstract: An apparatus and method is provided for storing and retrieving information from a disk in which a TPI (tracks per inch) profile of a disk drive including a write pole having a trapezoidal cross-section is adaptively varied. The method includes comparing the slope angle of sides of a write pole associated with a magnetic head to a skew angle associated with a disk area; and dividing the disk areas into a first area in which the slope angle is greater than the skew angle and a second area in which the slope angle is not greater than the skew angle. Based on this comparison result, different track pitches for the first area and the second area are determined.
    Type: Grant
    Filed: December 1, 2006
    Date of Patent: August 19, 2008
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Yoon-chul Cho, Keung-youn Cho
  • Patent number: 7253978
    Abstract: The invention includes a testing method which may be applied to at least one writer in a disk drive during the self-test phase to generate write parameters, focused on the Over Shoot Control (OSC) of the write current parameter to improve the reliability of write operations by that writer. The Minimum OSC is used for write operations in normal temperatures. The Optimum OSC is used for a first lower temperature range, preferably between essentially 15 degrees Centigrade and essentially 5 degrees Centigrade. The Maximum OSC is preferred below essentially 5 degrees Centigrade. The Minimum OSC should preferably guarantee both an Adjacent Track Write (ATW) criteria, as well as guarantee a Write Induced Instability (WII) criteria. The invention includes the write parameter collection, as well as the disk drive containing the generated write parameter collection.
    Type: Grant
    Filed: July 6, 2005
    Date of Patent: August 7, 2007
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Hae Jung Lee, Sang Lee, Keung Youn Cho
  • Publication number: 20070127150
    Abstract: An apparatus and method is provided for storing and retrieving information from a disk in which a TPI (tracks per inch) profile of a disk drive including a write pole having a trapezoidal cross-section is adaptively varied. The method includes comparing the slope angle of sides of a write pole associated with a magnetic head to a skew angle associated with a disk area; and dividing the disk areas into a first area in which the slope angle is greater than the skew angle and a second area in which the slope angle is not greater than the skew angle. Based on this comparison result, different track pitches for the first area and the second area are determined.
    Type: Application
    Filed: December 1, 2006
    Publication date: June 7, 2007
    Inventors: Yoon-chul Cho, Keung-youn Cho
  • Patent number: 7089649
    Abstract: Thermal pole tip protrusion is caused by materials in and around head slider expanding during write operations till they protrude, leading to contact with the rotating disk surface, altering the flying height and often wearing down part of the disk surface. While well known that read-write heads expand during writing, the inventors who recognized this situation's significance, particularly as flying height decreases and data rates increase, both required for high areal density disk drives. The inventors realized that they could detect the problem at the spin stand level by testing head gimbal assemblies to reliably, and inexpensively, predict the tendency for thermal pole tip protrusion. This leads to selection of head gimbal assemblies, which do not have the thermal pole tip protrusion tendency. The selected head gimbal assemblies have better reliability, as do actuators and disk drives made with the selected head gimbal assemblies.
    Type: Grant
    Filed: September 26, 2002
    Date of Patent: August 15, 2006
    Assignee: Samsung Electronics Co. Ltd,
    Inventors: Geng Wang, Hae Jung Lee, Keung Youn Cho, Sang Lee
  • Publication number: 20060139788
    Abstract: A method, medium, and apparatus recording a magnetic disk servo pattern. The method of recording a servo pattern, including servo information, on a magnetic disk may include an erasing of erase regions existing between burst signals contained in a burst signal recording zone of a servo pattern of the magnetic disk by applying an AC current signal of a predetermined frequency to the erase regions.
    Type: Application
    Filed: December 27, 2005
    Publication date: June 29, 2006
    Applicant: Samsung Electronics Co., Ltd.
    Inventors: Won-choul Yang, Keung-Youn Cho
  • Publication number: 20060139808
    Abstract: A head slider, and a hard disk drive having the head slider, the head slider including a slider body; a magnetic head provided on the slider body, the magnetic head including a writer to write data on a disk and a reader to read data written on the disk; and a shield layer to prevent penetration of an external magnetic field.
    Type: Application
    Filed: December 6, 2005
    Publication date: June 29, 2006
    Applicant: SAMSUNG ELECTRONICS CO., LTD.
    Inventors: Sung-chul Kim, Keung-Youn Cho
  • Patent number: 6975475
    Abstract: The invention includes a testing method which may be applied to at least one writer in a disk drive during the self-test phase to generate write parameters, focused on the Over Shoot Control (OSC) of the write current parameter to improve the reliability of write operations by that writer. The Minimum OSC is used for write operations in normal temperatures. The Optimum OSC is used for a first lower temperature range, preferably between essentially 15° Centigrade and essentially 5° Centigrade. The Maximum OSC is preferred below essentially 5° C. The Minimum OSC should preferably guarantee both an Adjacent Track Write (ATW) criteria, as well as guarantee a Write Induced Instability (WII) criteria. The invention includes the write parameter collection, as well as the disk drive containing the generated write parameter collection.
    Type: Grant
    Filed: November 14, 2002
    Date of Patent: December 13, 2005
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Hae Jung Lee, Sang Lee, Keung Youn Cho
  • Patent number: 6791780
    Abstract: The present invention is a method and system to optimize a write channel in a hard disk drive. The method comprises providing a disk having a at least one side with a plurality of tracks, and selecting a target track from the plurality of tracks. Data is written at least once on a predetermined plurality of tracks adjacent to either side of the target track and on the target track. Data is also written a predetermined number of times on tracks immediately adjacent to the target track. Data written on the predetermined plurality of tracks adjacent to either side of the target track and on the target track is then read. The process then determines if a number of errors on the tracks is greater than a predetermined criteria, if so, a write current value of the write channel is decreased, otherwise the write current value is increased.
    Type: Grant
    Filed: October 15, 2001
    Date of Patent: September 14, 2004
    Assignee: Samsung Electronics Co., Inc.
    Inventors: Hae Jung Lee, Sang Lee, Keung Youn Cho, Ken Bovatsek
  • Patent number: 6791775
    Abstract: The present invention is a method and system to determine a quality of a head in a hard disk drive. The method comprises providing a disk having a at least one side with a plurality of tracks, writing on a predetermined track on the plurality of tracks and reading a profile of the predetermined track to provide a first profile value. The head is then moved to an adjacent track where it writes on the adjacent track. A profile of the predetermined track is then read to provide a second profile value. A quality of the head can then be determined based on the first and second values.
    Type: Grant
    Filed: October 15, 2001
    Date of Patent: September 14, 2004
    Assignee: Samsung Electronics, Co., Inc.
    Inventors: Zhaohui Li, Geng Wang, Keung Youn Cho
  • Publication number: 20040060167
    Abstract: Thermal pole tip protrusion is caused by the materials in and around the head slider expanding during write operations till part of those materials protrude, leading to contact with the rotating disk surface, altering the flying height and often wearing down part of the disk surface. While it is well known that read-write heads expand during writing, the inventors are unaware of anyone else who recognized this situation's significance, particularly as the flying height decreases and the data rates increase, both of which are required for high areal density disk drives. The inventors realized that they could detect the problem at the spin stand level by testing head gimbal assemblies to reliably, and inexpensively, predict the tendency for thermal pole tip protrusion. This leads to selection of head gimbal assemblies, which do not have the thermal pole tip protrusion tendency.
    Type: Application
    Filed: September 26, 2002
    Publication date: April 1, 2004
    Inventors: Geng Wang, Hae Jung Lee, Keung Youn Cho, Sang Lee