公开(公告)号：JP2000137960A

公开(公告)日：2000-05-16

申请号：JP30892398

申请日：1998-10-29

Applicant: IBM

Inventor： KAGAMI NAOYUKI ,  TOKIZONO AKIRA ,  MUTUTANBII SURIIJAYANTA ,  SAKAI TATSUYA ,  YONEDA ISAO ,  HIEN FUU DAN ,  ARN SHARMA

IPC: G11B21/10 ,  G11B5/55 ,  G11B5/56 ,  G11B19/28 ,  H03H17/02 ,  G11B19/247

Abstract: PROBLEM TO BE SOLVED: To effectively perform disturbance suppression, mechanical resonance suppression by providing plural filter means and constituting the filter means in multistage with a parallel or serial form for a position control output with instructions of an MPU when an actuator is position controlled. SOLUTION: A servo control part SV 21 receives a signal from a servo pattern of a magnetic disk 1 to process it, and generates a servo signal output DACOUT moving a head arm 3 through a hardware sequencer SA 23 to send it to a voice coil motor VCM drive part 6. The SA 23 consists of plural digital filters, and sets arrangement of respective digital filters for the servo signal output DACOUT based on the instructions from the MPU 40. For instance, peak filters are arranged serially, and a peak is given to an output gain at a required frequency. Or, notch filters are arranged parallel, and the output gain suppressing the mechanical resonance is obtained.

公开(公告)号：JP2000048509A

公开(公告)日：2000-02-18

申请号：JP20168399

申请日：1999-07-15

Applicant: IBM

Inventor： SURI MUSHUZAMBI SURIIJAYANZA ,  ARN SHARMA ,  HEIN HUGH DAN ,  KAGAMI NAOYUKI ,  NAKAGAWA YUZO ,  TOKIZONO AKIRA ,  YONEDA ISAO

IPC: G11B21/02 ,  G11B5/596 ,  G11B21/10 ,  G11B21/21

Abstract: PROBLEM TO BE SOLVED: To compensate for vibration that is encountered in a disk drive by first detecting a governing vibration frequency and then executing a two-step algorithm for constituting an optimum servo feedback solution. SOLUTION: A detection filter for scanning a positional signal over the frequency range of vibration is composed while a data storage is operating, amplitude related to frequency is recorded, it is judged whether the recorded amplitude exceeds a specific threshold or not, the corresponding frequency of vibration is detected accordingly, and the frequency of vibration is detected. A correction filter using a plurality of filter coefficients being determined as the function of the detection frequency of vibration is constituted, and the influence of the detection frequency of vibration for the positional signal is reduced. External and internal vibrations are targeted as vibration. When the correction filter is repeatedly involved, the filter state vector as initial filter conditions is refreshed periodically in response to output from the correction filter.

公开(公告)号：JP2002258902A

公开(公告)日：2002-09-13

申请号：JP2001053226

申请日：2001-02-27

Applicant: IBM

Inventor： UCHIDA HIROSHI ,  SENBA TETSUO ,  YUZUBA AKINORI ,  TOKIZONO AKIRA ,  KAGAMI NAOYUKI ,  OKADA KENJI

IPC: G11B21/08 ,  G05B11/32 ,  G05B13/04 ,  G11B5/596

Abstract: PROBLEM TO BE SOLVED: To reduce a modeling error including a control model assumed under model follow-up control to a level in which any practical problem is not generated concerning a gain and a phase. SOLUTION: In a control means having a feed-forward system and a feedback system, a control model for generating reference position data yr from a feed- forward control signal Uff0 is divided into an original control model 22 and a correction filter 23. Also, the gain correction of the feed-forward control signal Uff0 is operated by a gain correcting means 24, and a corrected feed- forward control signal Uff is generated. The reference position data yr are inputted to a feedback controller 25, and a feedback control signal Ufb being the output of the feedback controller 25 and the feed-forward control signal Uff are inputted to an object 26 to be controlled. The coefficients of a correction filter 23 and a gain correcting means 24 are corrected according to a head orbit based on the actual seek operation.

公开(公告)号：JP2000132933A

公开(公告)日：2000-05-12

申请号：JP30081298

申请日：1998-10-22

Applicant: IBM

Inventor： MATSUBARA NOBUYA ,  KAGAMI NAOYUKI ,  TOKIZONO AKIRA

IPC: G11B5/00 ,  G11B5/012 ,  G11B5/31 ,  G11B5/455 ,  G11B5/596 ,  G11B21/10 ,  G11B27/36

Abstract: PROBLEM TO BE SOLVED: To provide a data writing control method of a head which can prevent off-track writing, accidental writing of data into an off track during the writing of data with the head and a memory device utilizing the same. SOLUTION: An amplitude value of an output signal of a magnetic head 6 in a servo region is preferably or constantly monitored. In the preferable embodiment, the amplitude value of the output signal is obtained from a value as given when a voltage of a capacitor 15 used at a VGA(Variable Gain Control) 13 in an AGC(Automatic Gain Control) 12 of a channel unit 11 composing one circuit of a hard disc drive is measured and undergoes an A/D conversion. Then, it is judged whether the obtained amplitude value is abnormal or nor. When it is abnormal, the writing of data to be stored by the magnetic head 6 is stopped. In the ideal example, the abnormality is determined when the amplitude value of the output signal of the magnetic head is smaller than the amplitude value previously determined of the output signal in the normal magnetic head. The data writing control method of the head thus obtained is utilized for a memory device.

公开(公告)号：JPH09180388A

公开(公告)日：1997-07-11

申请号：JP22336396

申请日：1996-08-26

Applicant: IBM

Inventor： KAGAMI NAOYUKI ,  TOKIZONO AKIRA ,  NAKAGAWA YUZO

IPC: G11B21/10

Abstract: PROBLEM TO BE SOLVED: To detect the position of a magnetic head over a wide range with a easy processing. SOLUTION: When optimum gains Hs are not set, the correspondence between a physical position and a position detection signal in the case of performing a track following by making a position shifted by one fourth of one track width with respect to the center of a data track in a specific data track, does not become stable by being changed in between the output corresponding to a point X1 and the output corresponding to a point X2 because it becomes a main positioning signal mp and a slave positioning signal up. Therefore, the correspondence is brought near an ideal straight line th by preliminarily obtaining gains of the main positioning signal mp and the slave positioning signal np and by multiplying the output signals of magnetic heads with the gains and the track following can be performed stably in the vicinity of the target position by using the outputs of the signals as position detection signals.

公开(公告)号：JP2002100139A

公开(公告)日：2002-04-05

申请号：JP2000275184

申请日：2000-09-11

Applicant: IBM

Inventor： TOKIZONO AKIRA ,  KADOKAWA TOSHIHIKO ,  KANAMARU MASAYUKI ,  OTA SHUNICHIRO ,  KAGAMI NAOYUKI

IPC: G11B21/12 ,  G11B5/012 ,  G11B5/54 ,  G11B21/22 ,  G11B33/14

Abstract: PROBLEM TO BE SOLVED: To remove contamination without the occurrence of fresh contamination by contact of a head and a disk. SOLUTION: Track following is performed in the outer peripheral part of the disk outside an effective recording region for a specified period after the head 3 is loaded onto the disk 1 from a ramp loading mechanism 17. The movement to the inner side of the disk and the movement to the outer side thereof are repeated in the outer peripheral part after the track following in the outer peripheral part of the disk. The velocity Vout of the outer side moving is set larger than the velocity Vin of the inner side moving, more preferably at about several times.

公开(公告)号：JPH1196704A

公开(公告)日：1999-04-09

申请号：JP25844297

申请日：1997-09-24

Applicant: IBM

Inventor： SENBA TETSUO ,  KAGAMI NAOYUKI ,  TOKIZONO AKIRA

IPC: G11B21/10 ,  G05B11/36 ,  G05B13/02 ,  G05D3/10 ,  G11B5/596 ,  H02P29/00

Abstract: PROBLEM TO BE SOLVED: To stably perform feedback control even when mechanical resonances exist in plural frequencies in a hard disk device. etc., performing positioning control by selecting an optimum notch filter so that the useless peak of an open loop gain is lowered based on the shape of a transfer function without directly measuring the frequency at the peak of the transfer function. SOLUTION: Notch filters having a fixed phase delay in a control band frequency and having different central frequencies in the vicinity of the frequency that mechanical resonance desired to be suppressed exists are obtained beforehand by calculation to be stored in a memory 23. A CPU 21 selects two notch filters from the memory 23 and sets these coefficients successively in the notch filters in a servo processor 9. A drive CPU 13 injects a sine wave into the servo processor 9 at every frequency of a prescribed interval to transmit a position error signal to the CPU 21. Thus, the CPU 21 calculates the frequency characteristics of control loops containing the notch filters to set the optimum notch filter.

公开(公告)号：JPH04134737A

公开(公告)日：1992-05-08

申请号：JP25546890

申请日：1990-09-27

Applicant: IBM

Inventor： SOTOZONO KAZUO ,  SHINOHARA TATSUOKI ,  TOKIZONO AKIRA ,  UENO SHIGEO

IPC: G11B7/125 ,  G11B7/126

Abstract: PURPOSE: To enable a laser output to be set at the optimum value by determining such a digital value for setting an output as the laser output of a write mode is equal to that of a read mode and, on the basis of this value, deciding such a digital value for setting an output as a desired laser output is generated under the write mode. CONSTITUTION: A laser output from a laser diode 10 is detected by a light- quantity detector 16 and imparted in parallel to a voltage differential detector 18 and an analog-digital converter 20. The voltage differential detector 18, comparing this detected value with a reference voltage, imparting a voltage output in accordance with the comparison result to a driving circuit 26 through a switching circuit 24. In a read mode, the laser output is controlled so that the detection voltage of the light-quantity detector 16 is always equal to the reference voltage generated by a reference voltage generating circuit 22. Then, a digital value which generates a laser output equal to this reading power is detected and, on the basis of this value, a digital value which generates a desired laser output is determined. As a result, the laser output is set at the optimum value.

公开(公告)号：JP2003346439A

公开(公告)日：2003-12-05

申请号：JP2002156406

申请日：2002-05-29

Applicant: Internatl Business Mach Corp ,  インターナショナル・ビジネス・マシーンズ・コーポレーション

Inventor： SENBA TETSUO ,  KAGAMI NAOYUKI ,  TOKIZONO AKIRA ,  IKEDO MANABU

IPC: G11B21/10 ,  G11B5/55

CPC classification number: G11B5/5526 ,  G11B5/5582

Abstract: PROBLEM TO BE SOLVED: To effectively prevent erroneous operation in the correcting operation based on the sensor output by dynamically controlling a gain of a sensor.
SOLUTION: The device is furnished with a servo control part 10 constituting a servo loop for the seek of a head for reading and writing data with respect to a recording medium, a correction signal generation part 20 for generating the correction signal to correct the control by this servo control part 10 on the basis of the output of the specified sensor, and a correction signal control part 30 for predicting the effect obtained when this correction signal is injected to the servo loop and controlling whether this corrected signal is injected to the servo loop or not in accordance with the predicted result. Also, the gain of the sensor is dynamically controlled in accordance with the above predicted result.
COPYRIGHT: (C)2004,JPO

Abstract translation: 要解决的问题：通过动态地控制传感器的增益，有效地防止基于传感器输出的校正操作中的错误操作。 解决方案：该装置配有一个伺服控制部件10，该伺服控制部件10构成一个伺服回路，用于寻找一个相对于记录介质读取和写入数据的头部;校正信号产生部分20，用于产生校正信号以校正 该伺服控制部10基于指定的传感器的输出进行的控制，以及校正信号控制部30，用于预测当将该校正信号注入伺服回路时获得的效果，并控制是否将该校正信号注入到 伺服回路或不符合预测结果。 此外，传感器的增益根据上述预测结果动态地控制。 版权所有（C）2004，JPO

公开(公告)号：JP2000134982A

公开(公告)日：2000-05-12

申请号：JP30669998

申请日：1998-10-28

Applicant: IBM

Inventor： SHIMIZU YASUHITO ,  KAGAMI NAOYUKI ,  TOKIZONO AKIRA ,  OYAMA AKIHIRO

IPC: H02P1/52 ,  H02P6/06 ,  H02P6/08 ,  H02P6/20

Abstract: PROBLEM TO BE SOLVED: To provide a method for starting a spindle motor and a device utiliz ing it which enables the motor to start well even in the spindle motor having the number of poles and slots in the ratio of 4:3, which is liable to cause a starting failure easily. SOLUTION: This method for starting a spindle motor 1 is intended for the spindle motor 1 having the number of poles and slots in the ratio of 4:3, which is liable to cause a starting failure easily. In this spindle motor 1, the timing of a starting is created by breaking down torque balance between a rotor 2 and a stator 3. In this device, by breaking down torque balance between the rotor 2 and stator 3 at the time of starting, leaving from the magnetic balance can be effected immediately at the time of starting, and the starting failure can be avoided. As a result, in a hard disk drive, too, which uses the spindle motor 1 having the number of poles and slots in the ratio of 4:3, which is liable to cause a starting failure easily, the starting time of the hard disk drive can be shortened. Also, this device is provided with a means which breaks down the torque balance between the rotor 2 and stator 3 in starting to create the timing of a starting.