公开(公告)号：US20180330754A1

公开(公告)日：2018-11-15

申请号：US15594812

申请日：2017-05-15

Applicant: Seagate Technology LLC

Inventor： Riyan Mendonsa ,  Jon D. Trantham ,  James Dillon Kiely ,  Peng Li ,  Joshua Ward Christensen

IPC: G11B13/04 ,  G11B13/08 ,  G11B20/18

CPC classification number: G11B13/045 ,  G11B5/6088 ,  G11B7/126 ,  G11B13/08 ,  G11B20/1816 ,  G11B2005/0021

Abstract: An apparatus comprises a laser diode configured to generate light during a write operation. A slider comprises a near-field transducer (NFT) and an optical waveguide. The slider is configured for heat-assisted magnetic recording and to communicate the light to the NFT via the waveguide. A writer heater of the slider is configured to receive power during the write operation. A thermal sensor is situated at or near an air bearing surface of the slider. The thermal sensor is configured to produce a sensor signal in response to sensing back-heating from the medium while the NFT generates heat during a write operation. Circuitry, coupled to the thermal sensor, is configured to compare the sensor signal to a threshold and generate an output signal indicative of degradation of NFT performance in response to the sensor signal exceeding the threshold.

公开(公告)号：US09966100B1

公开(公告)日：2018-05-08

申请号：US15671262

申请日：2017-08-08

Applicant: Seagate Technology LLC

Inventor： Tim Rausch ,  Edward Charles Gage ,  Joshua Ward Christensen ,  Todd Michael Lammers

IPC: G11B5/02 ,  G11B7/00 ,  G11B7/1263 ,  G11B5/012 ,  H01S5/042 ,  H01S5/0683 ,  G11B5/00

CPC classification number: G11B5/012 ,  G11B2005/0021 ,  H01S5/0427 ,  H01S5/0683

Abstract: Before writing to a heat-assisted magnetic recording medium, a DC signal modulated with an AC signal is applied to a laser of a read/write head. A modulation level of an optical power sensor is measured, the optical power sensor being coupled to detect optical output of the laser in response to the modulated current. A target value of the DC signal that causes the modulation levels to reach a predetermined value between zero and a maximum value is determined and used to set a bias current for subsequent activation of the laser based.

公开(公告)号：US10777224B2

公开(公告)日：2020-09-15

申请号：US16556501

申请日：2019-08-30

Applicant: SEAGATE TECHNOLOGY LLC

Inventor： Timothy Francis Ellis ,  Gary Ernest Hillukka ,  Joshua Ward Christensen ,  Puskal Prasad Pokharel

IPC: G11B5/596 ,  G11B20/12

Abstract: Systems and methods for servo zone transition optimization are described. In one embodiment, the storage system device includes a disk drive and a controller. In some embodiments, the controller may be configured to assess at least one operation of a read/write head of the disk drive; and format, based at least in part on the assessing of the read/write head, a disk surface of the disk drive with a first servo zone, a second servo zone, and an overlap region extending between a start point of the second servo zone and an end point of the first servo zone. In some cases, the overlap region starts towards a disk inner diameter (ID) and ends towards a disk outer diameter (OD).

公开(公告)号：US20190385640A1

公开(公告)日：2019-12-19

申请号：US16556501

申请日：2019-08-30

Applicant: SEAGATE TECHNOLOGY LLC

Inventor： Timothy Francis ELLIS ,  Gary Ernest HILLUKKA ,  Joshua Ward Christensen ,  Puskal Prasad POKHAREL

IPC: G11B5/596 ,  G11B20/12

Abstract: Systems and methods for servo zone transition optimization are described. In one embodiment, the storage system device includes a disk drive and a controller. In some embodiments, the controller may be configured to assess at least one operation of a read/write head of the disk drive; and format, based at least in part on the assessing of the read/write head, a disk surface of the disk drive with a first servo zone, a second servo zone, and an overlap region extending between a start point of the second servo zone and an end point of the first servo zone. In some cases, the overlap region starts towards a disk inner diameter (ID) and ends towards a disk outer diameter (OD).

公开(公告)号：US10366722B1

公开(公告)日：2019-07-30

申请号：US15978432

申请日：2018-05-14

Applicant: Seagate Technology LLC

Inventor： Riyan Mendonsa ,  James Dillon Kiely ,  Joshua Ward Christensen ,  Jon D. Trantham ,  Chad Robert Barry ,  Tim Rausch

IPC: G11B11/00 ,  G11B7/1263 ,  G11B5/00 ,  G11B7/1267 ,  G11B5/60 ,  G11B7/126

Abstract: An apparatus comprises a laser diode configured to generate modulated light during a write operation in response to receiving modulated current having a mean amplitude that varies or is constant. A slider is configured for heat-assisted magnetic recording and to receive the modulated light. A writer heater of the slider is configured to receive power during the write operation having a magnitude that varies or is constant. A sensor is situated on or within the slider. The sensor is configured to produce a sensor signal representative of output optical power of the laser diode. Measuring circuitry is coupled to the sensor and configured to measure a change in the sensor signal indicative of a laser mode hop during the write operation.

公开(公告)号：US20180114542A1

公开(公告)日：2018-04-26

申请号：US15671262

申请日：2017-08-08

Applicant: Seagate Technology LLC

Inventor： Tim Rausch ,  Edward Charles Gage ,  Joshua Ward Christensen ,  Todd Michael Lammers

IPC: G11B7/1263 ,  H01S5/0683 ,  G11B5/012 ,  H01S5/042 ,  G11B5/00

CPC classification number: G11B5/012 ,  G11B2005/0021 ,  H01S5/0427 ,  H01S5/0683

Abstract: Before writing to a heat-assisted magnetic recording medium, a DC signal modulated with an AC signal is applied to a laser of a read/write head. A modulation level of an optical power sensor is measured, the optical power sensor being coupled to detect optical output of the laser in response to the modulated current. A target value of the DC signal that causes the modulation levels to reach a predetermined value between zero and a maximum value is determined and used to set a bias current for subsequent activation of the laser based.

公开(公告)号：US10482908B2

公开(公告)日：2019-11-19

申请号：US16193189

申请日：2018-11-16

Applicant: Seagate Technology LLC

Inventor： Riyan Mendonsa ,  Jon D. Trantham ,  James Dillon Kiely ,  Peng Li ,  Joshua Ward Christensen

IPC: G11B11/105 ,  G11B5/455 ,  G11B5/60 ,  G11B5/00 ,  G11B7/126

Abstract: An apparatus comprises a laser diode configured to generate light during a write operation. A slider comprises a near-field transducer (NFT) and an optical waveguide. The slider is configured for heat-assisted magnetic recording and to communicate the light to the NFT via the waveguide. A writer heater of the slider is configured to receive power during the write operation. A thermal sensor is situated at or near an air bearing surface of the slider. The thermal sensor is configured to produce a sensor signal in response to sensing back-heating from the medium while the NFT generates heat during a write operation. Circuitry, coupled to the thermal sensor, is configured to compare the sensor signal to a threshold and generate an output signal indicative of degradation of NFT performance in response to the sensor signal exceeding the threshold.

公开(公告)号：US10438620B1

公开(公告)日：2019-10-08

申请号：US15936215

申请日：2018-03-26

Applicant: SEAGATE TECHNOLOGY LLC

Inventor： Timothy Francis Ellis ,  Gary Ernest Hillukka ,  Joshua Ward Christensen ,  Puskal Prasad Pokharel

IPC: G11B5/596 ,  G11B20/12

Abstract: Systems and methods for servo zone transition optimization are described. In one embodiment, the storage system device includes a disk drive and a controller. In some embodiments, the controller may be configured to assess at least one operation of a read/write head of the disk drive; and format, based at least in part on the assessing of the read/write head, a disk surface of the disk drive with a first servo zone, a second servo zone, and an overlap region extending between a start point of the second servo zone and an end point of the first servo zone. In some cases, the overlap region starts towards a disk inner diameter (ID) and ends towards a disk outer diameter (OD).

公开(公告)号：US20190103132A1

公开(公告)日：2019-04-04

申请号：US16193189

申请日：2018-11-16

Applicant: Seagate Technology LLC

Inventor： Riyan Mendonsa ,  Jon D. Trantham ,  James Dillon Kiely ,  Peng Li ,  Joshua Ward Christensen

IPC: G11B5/455 ,  G11B5/60 ,  G11B5/00 ,  G11B7/126

Abstract: An apparatus comprises a laser diode configured to generate light during a write operation. A slider comprises a near-field transducer (NFT) and an optical waveguide. The slider is configured for heat-assisted magnetic recording and to communicate the light to the NFT via the waveguide. A writer heater of the slider is configured to receive power during the write operation. A thermal sensor is situated at or near an air bearing surface of the slider. The thermal sensor is configured to produce a sensor signal in response to sensing back-heating from the medium while the NFT generates heat during a write operation. Circuitry, coupled to the thermal sensor, is configured to compare the sensor signal to a threshold and generate an output signal indicative of degradation of NFT performance in response to the sensor signal exceeding the threshold.

公开(公告)号：US09741386B1

公开(公告)日：2017-08-22

申请号：US15333761

申请日：2016-10-25

Applicant: Seagate Technology LLC

Inventor： Tim Rausch ,  Edward Charles Gage ,  Joshua Ward Christensen ,  Todd Michael Lammers

IPC: G11B5/02 ,  G11B7/00 ,  G11B7/1263 ,  H01S5/042 ,  H01S5/0683 ,  G11B5/012 ,  G11B5/00

CPC classification number: G11B5/012 ,  G11B2005/0021 ,  H01S5/0427 ,  H01S5/0683

Abstract: Before writing to a heat-assisted magnetic recording medium, a current of a laser is modulated about a default threshold current level. A modulation level of an optical power sensor is measured, the optical power sensor being coupled to detect optical output of the laser in response to the modulated current. A bias current for subsequent activation of the laser is adjusted based on the modulation level of the optical power sensor.