Patents by Inventor Huazhou Lou
Huazhou Lou 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).
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Patent number: 9236081Abstract: A method includes setting a heat assisted magnetic recording (HAMR) device located in a data storage system having a laser to an operating temperature. A threshold laser current is determined. An optimal laser current is determined. The threshold laser current and the optimal laser current are stored in memory. The steps of determining a threshold laser current, determining an optimal laser current and storing the threshold laser current and the optimal laser current into the calibration table are repeated until acceptable device performance is achieved at more than one operating temperature.Type: GrantFiled: March 31, 2015Date of Patent: January 12, 2016Assignee: Seagate Technology LLCInventors: Alfredo S. Chu, Jason W. Riddering, Drew M. Mader, Huazhou Lou, Pu-Ling Lu
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Patent number: 9230594Abstract: A temperature sensor of a head transducer measures temperature near or at the close point. The measured temperature varies in response to changes in spacing between the head transducer and a magnetic recording medium. A detector is coupled to the temperature sensor and is configured to detect a change in a DC component of the measured temperature indicative of onset of contact between the head transducer and the medium. Another head transducer configuration includes a sensor having a sensing element with a high temperature coefficient of resistance to interact with asperities of the medium. Electrically conductive leads are connected to the sensing element and have a low temperature coefficient of resistance relative to that of the sensing element, such thermally induced resistance changes in the leads have a negligible effect on a response of the sensing element to contact with the asperities.Type: GrantFiled: May 27, 2014Date of Patent: January 5, 2016Assignee: SEAGATE TECHNOLOGY LLCInventors: Gary Joseph Kunkel, Huazhou Lou, Declan Macken, Timothy William Stoebe
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Patent number: 9171581Abstract: The application discloses a sensor device to measure friction force at a head-media interface. As disclosed, the sensor device has a transducer element oriented to provide an electrical output responsive to force or strain imparted to the transducer element along an in-plane axis. Sensor circuitry is coupled to the transducer element to process the electrical output to provide an output measure of friction force. In illustrated embodiments, the head includes an actuator element which is powered on/off at an on/off frequency to cyclically protrude a localized portion of the head. The on/off frequency of the actuator is used by the sensor circuitry to detect excitation of the sensor device due to friction force at the head-media interface.Type: GrantFiled: March 8, 2013Date of Patent: October 27, 2015Assignee: Seagate Technology LLCInventors: Huazhou Lou, Lin Zhou
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Publication number: 20150255102Abstract: A head transducer, configured to interact with a magnetic recording medium, includes a first sensor having a temperature coefficient of resistance (TCR) and configured to produce a first sensor signal, and a second sensor having a TCR and configured to produce a second sensor signal. One of the first and second sensors is situated at or near a close point of the head transducer in relation to the magnetic recording medium, and the other of the first and second sensors spaced away from the close point. Circuitry is configured to combine the first and second sensor signals and produce a combined sensor signal indicative of one or both of a change in head-medium spacing and head-medium contact. Each of the sensors may have a TCR with the same sign (positive or negative) or each sensor may have a TCR with a different sign.Type: ApplicationFiled: May 22, 2015Publication date: September 10, 2015Inventors: Michael Thomas Johnson, Dongming Liu, Huazhou Lou, Declan Macken, Timothy William Stoebe, James Gary Wessel, Xuan Zheng
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Patent number: 9123371Abstract: In certain embodiments, a head-suspension assembly includes a resonator attached to either a head or gimbal. The resonator is configured to resonate at a predefined resonant frequency. In certain embodiments, disc drives includes a recording medium, a head-suspension assembly, and a resonator. The resonator is attached to either a head or gimbal of the head-suspension assembly. The resonator is configured to resonate at a predefined resonant frequency.Type: GrantFiled: October 10, 2013Date of Patent: September 1, 2015Assignee: SEAGATE TECHNOLOGY LLCInventors: Huazhou Lou, Lin Zhou, Vincent Engelkes
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Patent number: 9042050Abstract: A head transducer, configured to interact with a magnetic recording medium, includes a first sensor having a temperature coefficient of resistance (TCR) and configured to produce a first sensor signal, and a second sensor having a TCR and configured to produce a second sensor signal. One of the first and second sensors is situated at or near a close point of the head transducer in relation to the magnetic recording medium, and the other of the first and second sensors spaced away from the close point. Circuitry is configured to combine the first and second sensor signals and produce a combined sensor signal indicative of one or both of a change in head-medium spacing and head-medium contact. Each of the sensors may have a TCR with the same sign (positive or negative) or each sensor may have a TCR with a different sign.Type: GrantFiled: August 12, 2014Date of Patent: May 26, 2015Assignee: SEAGATE TECHNOLOGY LLCInventors: Michael Thomas Johnson, Dongming Liu, Huazhou Lou, Declan Macken, Timothy William Stoebe, James Gary Wessel, Xuan Zheng
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Patent number: 9036290Abstract: A head transducer, configured to interact with a magnetic recording medium, includes a first sensor having a temperature coefficient of resistance (TCR) and configured to produce a first sensor signal, and a second sensor having a TCR and configured to produce a second sensor signal. One of the first and second sensors is situated at or near a close point of the head transducer in relation to the magnetic recording medium, and the other of the first and second sensors spaced away from the close point. Circuitry is configured to combine the first and second sensor signals and produce a combined sensor signal indicative of one or both of a change in head-medium spacing and head-medium contact. Each of the sensors may have a TCR with the same sign (positive or negative) or each sensor may have a TCR with a different sign.Type: GrantFiled: August 12, 2014Date of Patent: May 19, 2015Assignee: SEAGATE TECHNOLOGY LLCInventors: Michael Thomas Johnson, Dongming Liu, Huazhou Lou, Declan Macken, Timothy William Stoebe, James Gary Wessel, Xuan Zheng
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Publication number: 20150103432Abstract: In certain embodiments, a head-suspension assembly includes a resonator attached to either a head or gimbal. The resonator is configured to resonate at a predefined resonant frequency. In certain embodiments, disc drives includes a recording medium, a head-suspension assembly, and a resonator. The resonator is attached to either a head or gimbal of the head-suspension assembly. The resonator is configured to resonate at a predefined resonant frequency.Type: ApplicationFiled: October 10, 2013Publication date: April 16, 2015Inventors: Huazhou Lou, Lin Zhou, Vincent Engelkes
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Publication number: 20140355150Abstract: A head transducer, configured to interact with a magnetic recording medium, includes a first sensor having a temperature coefficient of resistance (TCR) and configured to produce a first sensor signal, and a second sensor having a TCR and configured to produce a second sensor signal. One of the first and second sensors is situated at or near a close point of the head transducer in relation to the magnetic recording medium, and the other of the first and second sensors spaced away from the close point. Circuitry is configured to combine the first and second sensor signals and produce a combined sensor signal indicative of one or both of a change in head-medium spacing and head-medium contact. Each of the sensors may have a TCR with the same sign (positive or negative) or each sensor may have a TCR with a different sign.Type: ApplicationFiled: August 12, 2014Publication date: December 4, 2014Inventors: Michael Thomas Johnson, Dongming Liu, Huazhou Lou, Declan Macken, Timothy William Stoebe, James Gary Wessel, Xuan Zheng
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Publication number: 20140347760Abstract: A head transducer, configured to interact with a magnetic recording medium, includes a first sensor having a temperature coefficient of resistance (TCR) and configured to produce a first sensor signal, and a second sensor having a TCR and configured to produce a second sensor signal. One of the first and second sensors is situated at or near a close point of the head transducer in relation to the magnetic recording medium, and the other of the first and second sensors spaced away from the close point. Circuitry is configured to combine the first and second sensor signals and produce a combined sensor signal indicative of one or both of a change in head-medium spacing and head-medium contact. Each of the sensors may have a TCR with the same sign (positive or negative) or each sensor may have a TCR with a different sign.Type: ApplicationFiled: August 12, 2014Publication date: November 27, 2014Inventors: Michael Thomas Johnson, Dongming Liu, Huazhou Lou, Declan Macken, Timothy William Stoebe, James Gary Wessel, Xuan Zheng
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Publication number: 20140269241Abstract: Using a high sample rate dPES, together with pulsed heater and lock-in technique, to improve dPES SNR for contact detection between the head and media surface. Steps of powering a transducing head actuator with pulsed input signal at a select data track offset from a previously-written to data track of the storage medium, where the pulsed input signal has select amplitude and duty cycle to simulate a response signal, and further locking in an amplitude with respect to the heater frequency, can lead to a determination of level of heater power for initiating contact between the transducing head and the storage medium.Type: ApplicationFiled: March 15, 2013Publication date: September 18, 2014Inventors: Lin Zhou, Juil Lee, Dongming Liu, Huazhou Lou
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Publication number: 20140268410Abstract: A temperature sensor of a head transducer measures temperature near or at the close point. The measured temperature varies in response to changes in spacing between the head transducer and a magnetic recording medium. A detector is coupled to the temperature sensor and is configured to detect a change in a DC component of the measured temperature indicative of onset of contact between the head transducer and the medium. Another head transducer configuration includes a sensor having a sensing element with a high temperature coefficient of resistance to interact with asperities of the medium. Electrically conductive leads are connected to the sensing element and have a low temperature coefficient of resistance relative to that of the sensing element, such thermally induced resistance changes in the leads have a negligible effect on a response of the sensing element to contact with the asperities.Type: ApplicationFiled: May 27, 2014Publication date: September 18, 2014Applicant: Seagate Technology LLCInventors: Gary Joseph Kunkel, Huazhou Lou, Declan Macken, Timothy William Stoebe
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Publication number: 20140254341Abstract: The application discloses a sensor device to measure friction force at a head-media interface. As disclosed, the sensor device has a transducer element oriented to provide an electrical output responsive to force or strain imparted to the transducer element along an in-plane axis. Sensor circuitry is coupled to the transducer element to process the electrical output to provide an output measure of friction force. In illustrated embodiments, the head includes an actuator element which is powered on/off at an on/off frequency to cyclically protrude a localized portion of the head. The on/off frequency of the actuator is used by the sensor circuitry to detect excitation of the sensor device due to friction force at the head-media interface.Type: ApplicationFiled: March 8, 2013Publication date: September 11, 2014Applicant: Seagate Technology LLCInventors: Huazhou Lou, Lin Zhou
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Patent number: 8810952Abstract: A head transducer, configured to interact with a magnetic recording medium, includes a first sensor having a temperature coefficient of resistance (TCR) and configured to produce a first sensor signal, and a second sensor having a TCR and configured to produce a second sensor signal. One of the first and second sensors is situated at or near a close point of the head transducer in relation to the magnetic recording medium, and the other of the first and second sensors spaced away from the close point. Circuitry is configured to combine the first and second sensor signals and produce a combined sensor signal indicative of one or both of a change in head-medium spacing and head-medium contact. Each of the sensors may have a TCR with the same sign (positive or negative) or each sensor may have a TCR with a different sign.Type: GrantFiled: November 17, 2011Date of Patent: August 19, 2014Assignee: Seagate Technology LLCInventors: Michael T. Johnson, Dongming Liu, Huazhou Lou, Declan Macken, Timothy W. Stoebe, James G. Wessel, Xuan Zheng
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Patent number: 8737009Abstract: A temperature sensor of a head transducer measures temperature near or at the close point. The measured temperature varies in response to changes in spacing between the head transducer and a magnetic recording medium. A detector is coupled to the temperature sensor and is configured to detect a change in a DC component of the measured temperature indicative of onset of contact between the head transducer and the medium. Another head transducer configuration includes a sensor having a sensing element with a high temperature coefficient of resistance to interact with asperities of the medium. Electrically conductive leads are connected to the sensing element and have a low temperature coefficient of resistance relative to that of the sensing element, such thermally induced resistance changes in the leads have a negligible effect on a response of the sensing element to contact with the asperities.Type: GrantFiled: November 17, 2011Date of Patent: May 27, 2014Assignee: Seagate Technology LLCInventors: Gary J. Kunkel, Huazhou Lou, Declan Macken, Timothy W. Stoebe
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Publication number: 20140063644Abstract: An apparatus and generally associated method may be directed to a magnetic reader capable of concurrently or independently data access and environmental measurements. Various embodiments construct such a magnetic reader with first and second data transducing elements that are each adapted to selectively read data and measure clearance from an adjacent data storage media.Type: ApplicationFiled: August 29, 2012Publication date: March 6, 2014Applicant: SEAGATE TECHNOLOGY LLCInventors: Huazhou Lou, Manuel Charles Anaya Defresne, Declan Macken, Brian William Karr
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Publication number: 20140029139Abstract: A transducing device may include features for adjusting the fly height between the transducing device and a magnetic storage medium. In one example, the transducing device includes a transducing element, at least one heating element, a permanently deformable material portion, and a temporarily deformable material portion. In this example, the permanently deformable material portion is configured to permanently deform in response to heat from the at least one heating element, and the temporarily deformable material portion is configured to temporarily deform in response to heat from the at least one heating element. The fly height of the device may be adjusted using lower temperatures and less energy than some other types of devices.Type: ApplicationFiled: July 27, 2012Publication date: January 30, 2014Applicant: SEAGATE TECHNOLOGY LLCInventors: Vincent B. ENGELKES, Huazhou LOU
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Patent number: 8553350Abstract: A system that is capable of monitoring tribological data, such as friction, in a data storage device. In accordance with various embodiments, a magnetoresistive head is separated from a rotating data storage media by an air bearing and attached to a slider that is adjusted through deformation controlled by a heating element. A measurement circuit concurrently monitors friction from the head and power applied to the heating element to determine an MR head clearance. The measurement circuit includes at least a phase filter that eliminates off-phase friction from contributing to the determination of the MR head clearance.Type: GrantFiled: May 27, 2011Date of Patent: October 8, 2013Assignee: Seagate Technology LLCInventors: Lin Zhou, Huazhou Lou, Dongming Liu, Vincent Bernard Engelkes
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Publication number: 20120300335Abstract: A system that is capable of monitoring tribological data, such as friction, in a data storage device. In accordance with various embodiments, a magnetoresistive head is separated from a rotating data storage media by an air bearing and attached to a slider that is adjusted through deformation controlled by a heating element. A measurement circuit concurrently monitors friction from the head and power applied to the heating element to determine an MR head clearance. The measurement circuit includes at least a phase filter that eliminates off-phase friction from contributing to the determination of the MR head clearance.Type: ApplicationFiled: May 27, 2011Publication date: November 29, 2012Applicant: SEAGATE TECHNOLOGY LLCInventors: Lin Zhou, Huazhou Lou, Dongming Liu, Vincent Bernard Engelkes
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Publication number: 20120120519Abstract: A temperature sensor of a head transducer measures temperature near or at the close point. The measured temperature varies in response to changes in spacing between the head transducer and a magnetic recording medium. A detector is coupled to the temperature sensor and is configured to detect a change in a DC component of the measured temperature indicative of onset of contact between the head transducer and the medium. Another head transducer configuration includes a sensor having a sensing element with a high temperature coefficient of resistance to interact with asperities of the medium. Electrically conductive leads are connected to the sensing element and have a low temperature coefficient of resistance relative to that of the sensing element, such thermally induced resistance changes in the leads have a negligible effect on a response of the sensing element to contact with the asperities.Type: ApplicationFiled: November 17, 2011Publication date: May 17, 2012Applicant: SEAGATE TECHNOLOGY LLCInventors: Gary J. Kunkel, Huazhou Lou, Declan Macken, Timothy W. Stoebe