Patents by Inventor Fong Kheon Chong
Fong Kheon Chong 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).
-
Patent number: 9495987Abstract: The disclosed technology provides techniques for mitigating write-to-write bit error rate fluctuations that decrease accuracy of write precompensation (WPC) tuning. According to one implementation, such write-to-write bit error rate fluctuations are mitigated if a predetermined pattern is written at a particular radial offset from a target data track prior to testing a WPC register in association with the target data track. Selection of the particular radial offset can be performed according to an iterative offset track clean-up disclosed herein.Type: GrantFiled: May 1, 2015Date of Patent: November 15, 2016Assignee: SEAGATE TECHNOLOGY LLCInventors: Ben Niu, Lan Xia, Fong Kheon Chong, Quek Leong Choo, Song Wee Teo
-
Publication number: 20160322074Abstract: The disclosed technology provides techniques for mitigating write-to-write bit error rate fluctuations that decrease accuracy of write precompensation (WPC) tuning According to one implementation, such write-to-write bit error rate fluctuations are mitigated if a predetermined pattern is written at a particular radial offset from a target data track prior to testing a WPC register in association with the target data track. Selection of the particular radial offset can be performed according to an iterative offset track clean-up disclosed herein.Type: ApplicationFiled: May 1, 2015Publication date: November 3, 2016Inventors: Ben Niu, Lan Xia, Fong Kheon Chong, Quek Leong Choo, Song Wee Teo
-
Patent number: 6839193Abstract: A method for optimizing the read-to-write offset of a disk drive system in respect of a track is provided. In one aspect the method includes the step of determining a first read position amongst a range of test positions offset relative to the track on the basis of read signal strength. The method further includes the steps of calculating a subrange of test positions about the first read position, selecting a second read position from the subrange on the basis of bit error rates and setting the read-to-write offset as a function of the second read position. In addition a disk drive system including means for optimally setting the read-to-write offset in respect of a track is provided.Type: GrantFiled: December 11, 2001Date of Patent: January 4, 2005Assignee: Seagate Technology LLCInventors: Fong Kheon Chong, Quek Leong Choo, Myint Ngwe, Jun Wang, Kah Liang Gan
-
Patent number: 6822815Abstract: A magnetoresistive element measurement circuit configured for measuring resistance of a magnetoresistive element biased by a current source is disclosed. In a preferred embodiment, the measurement circuit includes the magnetoresistive element, a current source providing a fixed current to the magnetoresistive element, at least one current bypass switch controllingly engaging a measurement resistor in an electrical parallel configuration with the biased magnetoresistive element, and an analogue voltage detector measuring voltage first across the biased magnetoresistive element and then across the biased magnetoresistive element in electrical parallel communication with the measurement resistor. The measured voltages are factored with the measurement resistor to determine the resistance of the magnetoresistive element.Type: GrantFiled: June 28, 2002Date of Patent: November 23, 2004Assignee: Seagate Technology LLCInventors: Eng Hock Lim, Khai Sheng Ng, Fong Kheon Chong, Chew Weng Khin Victor, Myint Ngwe
-
Patent number: 6724550Abstract: A method for the adaptive dampening of a peak amplitude of a thermal asperity signal in a disc drive to minimize loss of read data integrity, including the steps of determining a peak-to-peak preamble signal amplitude for identifying an amplitude signal range of the peak amplitude of the thermal asperity signal; measuring the peak amplitude of the thermal asperity signal; separating the peak-to-peak preamble signal amplitude into substantially even portions for use in calculating a value of the amplitude signal range of the peak amplitude of the thermal asperity signal; calculating the value of the amplitude signal range of the peak amplitude of the thermal asperity signal for use in determining a dampening resistance used by a dampening circuit to adaptively dampen the peak amplitude of the thermal asperity signal; and activating the dampening circuit to dampen the peak amplitude of the thermal asperity signal.Type: GrantFiled: September 19, 2001Date of Patent: April 20, 2004Assignee: Seagate Technology LLCInventors: Eng Hock Lim, Beng Theam Ko, Hweepeng Teo, Fong Kheon Chong, Myint Ngwe, Kah Liang Gan
-
Publication number: 20030169528Abstract: A magnetoresistive element measurement circuit configured for measuring resistance of a magnetoresistive element biased by a current source is disclosed. In a preferred embodiment, the measurement circuit includes the magnetoresistive element, a current source providing a fixed current to the magnetoresistive element, at least one current bypass switch controllingly engaging a measurement resistor in an electrical parallel configuration with the biased magnetoresistive element, and an analogue voltage detector measuring voltage first across the biased magnetoresistive element and then across the biased magnetoresistive element in electrical parallel communication with the measurement resistor. The measured voltages are factored with the measurement resistor to determine the resistance of the magnetoresistive element.Type: ApplicationFiled: June 28, 2002Publication date: September 11, 2003Applicant: Seagate Technology LLCInventors: Eng Hock Lim, Khai Sheng Ng, Fong Kheon Chong, Chew Weng Khin Victor, Myint Ngwe
-
Patent number: 6606211Abstract: Apparatus for detecting defect in a recordable medium such as a disc drive is disclosed. The apparatus includes a recording system which write and read test data on the medium. The apparatus also includes a first comparator for comparing the read data to a first threshold. A first and a second counter, operably connected to the first comparator, are incremented when the read data exceeds the first threshold. When the first counter obtains a first count value, a first defect signal is produced. Data domains associated with the recordable medium are marked as bad in response to the first defect signal. When the second counter obtains a second count value, a second defect signal is produced and data sectors associated with the recordable medium are marked as bad in response to the second defect signal. A method for detecting defects in a recordable medium is also disclosed.Type: GrantFiled: April 19, 2000Date of Patent: August 12, 2003Assignee: Seagate Technology LLCInventors: Tuang Liang Bernard Lim, Myint Ngwe, Hwee Peng Teo, Fong Kheon Chong
-
Publication number: 20030026017Abstract: A method for optimizing the read-to-write offset of a disk drive system in respect of a track is provided. In one aspect the method includes the step of determining a first read position amongst a range of test positions offset relative to the track on the basis of read signal strength. The method further includes the steps of calculating a subrange of test positions about the first read position, selecting a second read position from the subrange on the basis of bit error rates and setting the read-to-write offset as a function of the second read position. In addition a disk drive system including means for optimally setting the read-to-write offset in respect of a track is provided.Type: ApplicationFiled: December 11, 2001Publication date: February 6, 2003Inventors: Fong Kheon Chong, Quek Leong Choo, Myint Ngwe, Jun Wang, Kah Liang Gan
-
Publication number: 20020126403Abstract: A method for the adaptive dampening of a peak amplitude of a thermal asperity signal in a disc drive to minimize loss of read data integrity, including the steps of determining a peak-to-peak preamble signal amplitude for identifying an amplitude signal range of the peak amplitude of the thermal asperity signal; measuring the peak amplitude of the thermal asperity signal; separating the peak-to-peak preamble signal amplitude into substantially even portions for use in calculating a value of the amplitude signal range of the peak amplitude of the thermal asperity signal; calculating the value of the amplitude signal range of the peak amplitude of the thermal asperity signal for use in determining a dampening resistance used by a dampening circuit to adaptively dampen the peak amplitude of the thermal asperity signal; and activating the dampening circuit to dampen the peak amplitude of the thermal asperity signal.Type: ApplicationFiled: September 19, 2001Publication date: September 12, 2002Applicant: SEAGATE TECHNOLOGY LLCInventors: Eng Hock Lim, Beng Theam Ko, Hweepeng Teo, Fong Kheon Chong, Myint Ngwe, Kah Liang Gan