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31.发明授权公开(公告)号：US11270733B2
公开(公告)日：2022-03-08
申请号：US17323474
申请日：2021-05-18
发明人： Ian James Gilbert , Peng Peng , Tim Rausch , Jan-Ulrich Thiele
IPC分类号： G11B11/105 , G11B20/10 , G11B5/73 , G11B20/18 , G11B5/00 , G11B7/126 , G11B7/1263 , G11B7/1267
摘要： A disk drive apparatus determines a pattern of bits of a data signal applied to a magnetic write transducer of a heat-assisted magnetic recording apparatus. The magnetic write transducer applies a magnetic field to a recording medium in response to the data signal. A laser power signal is applied to a laser that heats the recording medium while the magnetic field is applied. The laser power signal is modulated based on the pattern of bits. The modulation reduces differences between track widths of recorded marks having different elapsed time values and/or increases a signal-to-noise ratio of the recorded marks having different elapsed time values.
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公开(公告)号：US10325622B2
公开(公告)日：2019-06-18
申请号：US15947319
申请日：2018-04-06
发明人： Karim Tatah , Mourad Benakli , James Gary Wessel
IPC分类号： H01S5/06 , G11B7/1263 , H01S5/068 , H01S5/026 , H01S5/065 , G11B5/09 , G11B5/02 , G11B5/40 , G11B5/455 , G11B5/00 , H01S5/024 , H01S5/062
摘要： A method and apparatus provide for determining a temperature at a junction of a laser diode when the laser diode is operated in a lasing state that facilitates heat-assisted magnetic recording, comparing the junction temperature and an injection current supplied during the lasing state to stored combinations of junction temperature and injection current, and determining a likelihood of mode hopping occurring for the laser diode during the lasing state based on the comparison to stored combinations of junction temperature and injection current.
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33.发明授权公开(公告)号：US10192578B1
公开(公告)日：2019-01-29
申请号：US16049331
申请日：2018-07-30
IPC分类号： G11B5/00 , G11B7/1263 , G11B5/09 , G11B20/18 , G11B5/012
摘要： A slider configured for heat-assisted magnetic recording includes a laser diode optically coupled to a waveguide of the slider. A power supply is coupled to the laser diode. A preamplifier is coupled to the power supply. The preamplifier is configured to monitor a forward voltage across the laser diode while operating the laser diode at a constant current during a write operation, detect a change in the forward voltage indicative of laser power instability, and generate a signal in response to detecting the forward voltage change.
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34.发明授权公开(公告)号：US10134446B1
公开(公告)日：2018-11-20
申请号：US15918269
申请日：2018-03-12
发明人： Kangkang Wang , Xiaobin Zhu , Ganping Ju , Kai Chieh Chang , Yingguo Peng , Timothy J. Klemmer , Jan-Ulrich Thiele , Pin-Wei Huang
IPC分类号： G11B27/36 , G11B7/1267 , G11B5/024 , G11B5/09 , G11B7/1263 , G11B5/455 , G01R33/032 , G11B5/00
摘要： An apparatus comprises a spindle to rotate a magnetic recording medium and a magnetic field generator to expose a track of the medium to a DC magnetic field. The magnetic field generator is configured to saturate the track during an erase mode and reverse the DC magnetic field impinging the track during a writing mode. A laser arrangement heats the track during the erase mode and, during the writing mode, heats the track while the track is exposed to the reversed DC magnetic field so as to write a magnetic pattern thereon. A reader reads the magnetic pattern and generates a read signal. A processor is coupled to the reader and configured to determine an anisotropy parameter using the read signal. The apparatus can further comprise a Kerr sensor that generates a Kerr signal using the magnetic pattern.
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35.发明授权公开(公告)号：US10083716B1
公开(公告)日：2018-09-25
申请号：US15678440
申请日：2017-08-16
IPC分类号： G11B11/00 , G11B7/1267 , G11B20/12 , G11B5/455 , G11B5/00 , G11B7/126 , G11B7/1263 , G11B5/60
CPC分类号： G11B7/1267 , G11B5/455 , G11B5/5534 , G11B5/6088 , G11B7/126 , G11B7/1263 , G11B20/10027 , G11B20/1217 , G11B2005/0021 , G11B2020/1232
摘要： A heat-assisted magnetic recording head is moved relative to a magnetic recording medium. The medium comprises a plurality of sectors. The sectors define a plurality of sector groups distributed around a circumference of the medium. The sectors of each sector group are written using different operational currents supplied to a laser diode of the head such that at least one sector from each sector group is written using one of the different operational currents. For each of the different operational currents, an average write performance metric is calculated for all sectors written at each of the different operational currents. A particular operational current of the different operational currents is determined that results in a best average write performance metric.
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公开(公告)号：US10056106B1
公开(公告)日：2018-08-21
申请号：US15590743
申请日：2017-05-09
发明人： Scott O'Brien
IPC分类号： G11B11/00 , G11B7/126 , H05B37/02 , G11B5/012 , G11B7/13 , G11B20/18 , G11B5/00 , G11B7/1263 , G11B7/1267 , G11B5/60
CPC分类号： G11B5/012 , G11B5/5534 , G11B5/6088 , G11B7/1263 , G11B7/1267 , G11B2005/0021 , Y02B20/42 , Y02B20/46
摘要： A circuit includes a light source, a sensor, and a switch. The sensor measures output of the light source and provides an electrical signal to a feedback loop that is indicative of the measured output of the light source. The switch is positioned in the feedback loop and is movable between a first position and a second position depending upon whether the feedback loop is operating in a first mode of operation or a second mode of operation. During the first mode of operation the output of the feedback loop adjusts at least one operating parameter of the light source responsive to the electrical signal. During the second mode of operation the output of the feedback loop does not adjust the at least one operating parameter of the light source responsive to the electrical signal.
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37.发明授权公开(公告)号：US10043540B1
公开(公告)日：2018-08-07
申请号：US15667245
申请日：2017-08-02
发明人： Won Choul Yang
IPC分类号： G11B11/00 , G11B5/455 , G11B5/58 , G11B20/18 , G11B5/00 , G11B7/1263 , G11B7/1267 , G11B5/60 , G11B7/126
摘要： A method includes moving a heat-assisted magnetic recording head relative to a magnetic recording medium comprising a plurality of tracks, the head comprising a reader and a writer including a near-field transducer (NFT) optically coupled to a laser diode, the writer comprising a center which is laterally offset relative to a center of the reader to define a writer-reader offset (WRO) therebetween. Patterns are written to a particular track at a plurality of laser diode current levels. The patterns are read and a WRO value is calculated at a peak amplitude position for each of the laser diode current levels. A slope of the WRO values is determined with the laser current diode levels. A health condition of the NFT is determined by determining if the slope is greater than a predetermined threshold indicative of non-uniform activation across the NFT.
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38.发明申请公开(公告)号：US20180144770A1
公开(公告)日：2018-05-24
申请号：US15355891
申请日：2016-11-18
发明人： Lingtao Wang
IPC分类号： G11B7/0045 , G11B7/003 , G11B7/128 , G11B7/1263
CPC分类号： G11B7/00458 , G11B7/003 , G11B7/0062 , G11B7/1263 , G11B7/128 , G11B7/1353 , G11B7/1395 , G11B19/041 , G11B20/1879 , G11B2007/240017
摘要： An optical storage system includes an optical head configured to split a light beam into a higher power main beam and at least one lower power side beam. The optical storage system also includes a controller configured to alter an optical medium, via modulation of the higher power main beam according to a writing strategy waveform that defines at least n pulses for every n bits of data to be written to the medium, while processing a first signal resulting from the at least one lower power side beam being reflected from the medium and a second signal indicative of the writing strategy waveform to remove noise from the first signal caused by the higher power main beam to generate output indicative of the data directly after writing.
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公开(公告)号：US09922676B1
公开(公告)日：2018-03-20
申请号：US15616569
申请日：2017-06-07
发明人： Erhard Schreck , Oscar J. Ruiz , Na Wang , Shaomin Xiong , Qing Dai
IPC分类号： G11B7/00 , G11B7/1263
CPC分类号： G11B7/1263
摘要： A data storage device is disclosed comprising a head actuated over a disk, wherein the head comprises a laser configured to heat the disk while writing data to the disk. A write power is applied to the laser in order to write data to the disk during a write operation. A determination is made as to whether the laser power should be in an off state after the write operation. After the write operation, the laser power is gradually decreased to the off state based on a first decrease function.
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40.发明授权公开(公告)号：US09911450B1
公开(公告)日：2018-03-06
申请号：US15243457
申请日：2016-08-22
IPC分类号： G11B7/135 , G11B7/1395 , G11B7/1263
CPC分类号： G11B7/1395 , G11B7/003 , G11B7/00458 , G11B7/1263 , G11B7/1353
摘要： An optical storage system includes an optical head and a controller. The optical head is configured to split a light beam into a higher power main beam and a lower power side beam. The controller is configured to write data to an optical medium via the higher power main beam, and read, directly after writing, feedback from the optical medium containing the written data and noise caused by the higher power main beam. The controller is also configured to process the feedback using data indicative of the higher power main beam to remove the noise and generate output indicative of the written data, and automatically adjust a delay of the feedback or the data indicative of the higher power main beam based on a signal quality of the output.
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