公开(公告)号：US09799369B2

公开(公告)日：2017-10-24

申请号：US14950938

申请日：2015-11-24

Applicant: Western Digital Technologies, Inc.

Inventor： Satoshi Tabata ,  Atsushi Yamada ,  Michiya Kazusawa ,  Masato Shiimoto

IPC: G11B20/10 ,  G11B5/127 ,  G11B5/235 ,  G11B5/00 ,  G11B5/31

CPC classification number: G11B20/10009 ,  G11B5/02 ,  G11B5/1278 ,  G11B5/235 ,  G11B5/3153 ,  G11B5/40 ,  G11B5/465 ,  G11B2005/0024

Abstract: A magnetic recording system for preventing data loss resulting magnetic oscillator current. The magnetic recording system includes a magnetic write head with a magnetic write pole, a magnetic oscillator near the magnetic write pole, and a write coil for magnetizing the write pole. Circuitry is connected with the magnetic write coil to supply a current to the write coil and connected with the magnetic oscillator to supply a current to the magnetic oscillator. The circuitry is configured to ensure that the current to the magnetic oscillator does not inadvertently magnetize the write pole after the magnetic write pole has demagnetized.

公开(公告)号：US20150279416A1

公开(公告)日：2015-10-01

申请号：US14227933

申请日：2014-03-27

Applicant: HGST Netherlands B.V.

Inventor： Satoshi Tabata ,  Norifumi Miyamoto ,  Akira Morinaga ,  Masahiro Ito ,  Masahiko Hatatani

IPC: G11B20/10 ,  G11B5/11

CPC classification number: G11B20/10212 ,  G11B5/11 ,  G11B5/315 ,  G11B5/465 ,  G11B5/54 ,  G11B2005/0021

Abstract: A hard disk drive (HDD) is described which includes a magnetic field-generating device in the vicinity of a load/unload ramp such that the write head moves into a magnetic field generated by the device while the head is being unloaded from disk, whereby the magnetic field pins in a predominant direction the direction of magnetization of a magnetic shield associated with the write head, and away from the direction toward the disk. Recording magnetic field leakage associated with the shield is thereby suppressed and corresponding far track interference is inhibited.

Abstract translation: 描述了一种硬盘驱动器（HDD），其包括在加载/卸载斜坡附近的磁场产生装置，使得当磁头从磁盘卸载时，写入头移动到由装置产生的磁场中，由此 磁场引脚在主要方向上与写头相关联的磁屏蔽的磁化方向，并远离朝向盘的方向。 因此，与屏蔽相关的记录磁场泄漏被抑制，并且相应的远场干扰被抑制。

公开(公告)号：US20140240864A1

公开(公告)日：2014-08-28

申请号：US13873355

申请日：2013-04-30

Applicant: LSI Corporation

Inventor： Boris Livshitz ,  Paul Mazur ,  Anamul Hoque ,  Jason S. Goldberg

IPC: G11B5/09 ,  G11B20/10

CPC classification number: G11B20/10481 ,  G11B5/465 ,  G11B20/10027

Abstract: A hard disk drive or other storage device comprises a storage medium, a write head configured to write data to the storage medium, and control circuitry coupled to the write head. The control circuitry comprises degauss circuitry coupled to or otherwise associated with one or more write drivers. The degauss circuitry is configured to generate an asymmetric degauss signal to be applied to the write head. The asymmetric degauss signal has a waveform with upper and lower decay envelopes that are asymmetric about a specified degauss current level, such as a substantially zero current level.

Abstract translation: 硬盘驱动器或其他存储设备包括存储介质，被配置为将数据写入存储介质的写入头和耦合到写入头的控制电路。 控制电路包括耦合到一个或多个写入驱动器或以其它方式与一个或多个写入驱动器相关联的消磁电路。 消磁电路被配置为产生要施加到写入头的不对称消磁信号。 不对称消磁信号具有波形，其具有对于指定的消磁电流水平（例如基本为零电流水平）不对称的上部和下部衰减包络。

公开(公告)号：US08705196B2

公开(公告)日：2014-04-22

申请号：US13447741

申请日：2012-04-16

Applicant: Boris Livshitz ,  Anamul Hoque ,  Jason S. Goldberg

Inventor： Boris Livshitz ,  Anamul Hoque ,  Jason S. Goldberg

IPC: G11B5/02

CPC classification number: G11B20/10481 ,  G11B5/465 ,  G11B2220/2516

Abstract: A hard disk drive or other disk-based storage device comprises a storage disk, a write head configured to write data to the disk, and control circuitry coupled to the write head. The control circuitry comprises a write driver and degauss circuitry associated with the write driver. The degauss circuitry is configured to control a degauss signal waveform to be applied to the write head by the write driver, and comprises separate amplitude envelope control mechanisms for steady state and overshoot portions of the degauss signal waveform. The separate amplitude envelope control mechanisms may comprise, for example, separate steady state and overshoot controllers for controlling the amplitude envelope decay rates of the respective steady state and overshoot portions of the degauss signal waveform over the plurality of pulses.

Abstract translation: 硬盘驱动器或其他基于磁盘的存储设备包括存储盘，被配置为向盘写入数据的写入头以及耦合到写入头的控制电路。 控制电路包括与写入驱动器相关联的写入驱动器和消磁电路。 消磁电路被配置为控制由写入驱动器施加到写入头的消磁信号波形，并且包括用于消磁信号波形的稳态和过冲部分的单独的幅度包络控制机构。 单独的幅度包络控制机构可以包括例如单独的稳态和过冲控制器，用于控制各个稳态的幅度包络衰减速率以及多个脉冲上的消磁信号波形的部分。

公开(公告)号：US20090284860A1

公开(公告)日：2009-11-19

申请号：US12120525

申请日：2008-05-14

Applicant: TORU TAKEUCHI

Inventor： TORU TAKEUCHI

IPC: G11B15/18

CPC classification number: G11B5/465 ,  G11B2005/0018

Abstract: One embodiment of the invention includes a preamplifier system for a magnetic disk-drive. The system includes a current distributor configured to generate a reference current and to decay the reference current from a first magnitude to a second magnitude during a degauss period to degauss a magnetic disk write head. The degauss period defines a transition from a write cycle to a read cycle of the magnetic disk-drive and has a predetermined time duration that is independent of the first magnitude of the reference current during the write cycle. An output driver is configured to provide a write current to the magnetic disk write head having a magnitude with an absolute value that is based on the reference current.

Abstract translation: 本发明的一个实施例包括用于磁盘驱动器的前置放大器系统。 该系统包括配置成产生参考电流并且在消磁周期期间将参考电流从第一幅度衰减到第二幅值以消除磁盘写入头的电流分配器。 消磁周期定义从磁盘驱动器的写入周期到读取周期的转变，并且具有与写入周期期间的参考电流的第一幅度无关的预定持续时间。 输出驱动器被配置为向具有基于参考电流的绝对值的幅度的磁盘写入头提供写入电流。

公开(公告)号：US07411756B2

公开(公告)日：2008-08-12

申请号：US11052008

申请日：2005-02-04

Applicant: Ross Schwensen Wilson ,  Carl F. Elliott

Inventor： Ross Schwensen Wilson ,  Carl F. Elliott

IPC: G11B5/03 ,  G11B5/09

CPC classification number: G11B5/465 ,  G11B5/012 ,  G11B2005/0008 ,  G11B2005/0013 ,  G11B2005/0016

Abstract: An apparatus and method for demagnetizing a write head of a disc drive. Under control of a clock oscillator, synthetic demagnetizing pulses are generated and applied to a writer-driver bridge. Also under control of the clock oscillator, a write current produced by the writer-driver bridge incorporates the demagnetizing pulses and ramps down to about zero. The train of demagnetizing pulses and the write current ramp down demagnetizes the head, reducing write head magnetic bias that may influence the proximate read head of the disc drive head.

Abstract translation: 一种用于使磁盘驱动器的写入磁头消磁的装置和方法。 在时钟振荡器的控制下，产生合成去磁脉冲并将其应用于写入器 - 驱动器桥。 同样在时钟振荡器的控制下，由写入器 - 驱动器桥产生的写入电流包含消磁脉冲并且下降到大约零。 消磁脉冲串和写入电流斜坡降低磁头去磁，减少可能影响磁盘驱动器磁头的近似读取磁头的写头磁偏置。

公开(公告)号：US20060203382A1

公开(公告)日：2006-09-14

申请号：US11435053

申请日：2006-05-16

Applicant: Kochan Ju ,  Lijie Guan ,  Jeiwei Chang ,  Min Li ,  Ben Hu

Inventor： Kochan Ju ,  Lijie Guan ,  Jeiwei Chang ,  Min Li ,  Ben Hu

IPC: G11B5/127

CPC classification number: G11B5/1278 ,  G11B5/187 ,  G11B5/245 ,  G11B5/3156 ,  G11B5/465 ,  Y10T29/49032 ,  Y10T29/49043

Abstract: Single write poles tend to large shape anisotropy which results in a very large remnant field when not actually writing. This has now been eliminated by giving the write pole the form of a three layer laminate in which two ferromagnetic layers are separated by a non-magnetic or antiferromagnetic coupling layer. Strong magnetostatic coupling between the outer layers causes their magnetization directions to automatically be antiparallel to one another, unless overcome by the more powerful write field, leaving the structure with a low net magnetic moment. The thickness of the middle layer must be carefully controlled.

Abstract translation: 单写磁极往往具有大的形状各向异性，这在实际写入时导致非常大的残余磁场。 现在已经通过给写磁极制成三层层叠体的形式来消除这种情况，其中两个铁磁层被非磁性或反铁磁性耦合层分开。 外层之间的强静磁耦合使得它们的磁化方向自动地相互反平行，除非由更强大的写入场来克服，使结构具有低的净磁矩。 中间层的厚度必须仔细控制。

公开(公告)号：US07106536B2

公开(公告)日：2006-09-12

申请号：US10954599

申请日：2004-09-30

Applicant: Hao Fang ,  Stephen Carl Kuehne

Inventor： Hao Fang ,  Stephen Carl Kuehne

IPC: G11B5/02

CPC classification number: H01F13/006 ,  G11B5/465

Abstract: A demagnetizer for an inductive load having a driver circuit including at least one transistor and a ramp-down voltage source switchably connected to the driver circuit, so that when the ramp-down voltage source is connected to the transistor, it drives the voltage of the transistor below its threshold voltage.

Abstract translation: 一种用于感性负载的去磁器，具有包括至少一个晶体管的驱动器电路和可切换地连接到驱动器电路的斜降电压源，使得当斜坡下降电压源连接到晶体管时，其驱动电压 晶体管低于其阈值电压。

公开(公告)号：US20060176597A1

公开(公告)日：2006-08-10

申请号：US11052381

申请日：2005-02-07

Applicant: Tuan Ngo ,  Craig Brannon ,  John Price

Inventor： Tuan Ngo ,  Craig Brannon ,  John Price

IPC: G11B5/09 ,  G11B5/02

CPC classification number: G11B5/465

Abstract: A write head drive circuit for a magnetic data storage device is configured to drive a write head with a write head degaussing current that is applied at the end of a write cycle. The write head degaussing current is an alternating current waveform with a programmable number of current pulses with decreasing amplitude and a frequency controlled by a CMOS ring oscillator. The CMOS ring oscillator includes switchable feedback paths to control its frequency. A programmable timer terminates the write head degaussing current after an interval of time dependent on signals that indicate the programmable number of current pulses and the frequency of the CMOS oscillator.

Abstract translation: 用于磁数据存储装置的写头驱动电路被配置为以写周期结束时施加的写磁头消磁电流来驱动写头。 写头消磁电流是具有可编程数量的电流脉冲的交流电流波形，具有降低的幅度和由CMOS环形振荡器控制的频率。 CMOS环形振荡器包括可切换的反馈路径来控制其频率。 可编程定时器根据指示电流脉冲的可编程数量和CMOS振荡器的频率的信号间隔时间间隔终止写头去磁电流。

公开(公告)号：US07064924B2

公开(公告)日：2006-06-20

申请号：US10610036

申请日：2003-06-30

Applicant: Kochan Ju ,  Lijie Guan ,  Jeiwei Chang ,  Min Li ,  Ben Hu

Inventor： Kochan Ju ,  Lijie Guan ,  Jeiwei Chang ,  Min Li ,  Ben Hu

IPC: G11B5/147

CPC classification number: G11B5/1278 ,  G11B5/187 ,  G11B5/245 ,  G11B5/3156 ,  G11B5/465 ,  Y10T29/49032 ,  Y10T29/49043

Abstract: Single write poles tend to large shape anisotropy which results in a very large remnant field when not actually writing. This has now been eliminated by giving the write pole the form of a three layer laminate in which two ferromagnetic layers are separated by a non-magnetic or antiferromagnetic coupling layer. Strong magnetostatic coupling between the outer layers causes their magnetization directions to automatically be antiparallel to one another, unless overcome by the more powerful write field, leaving the structure with a low net magnetic moment. The thickness of the middle layer must be carefully controlled.