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：MY125903A

公开(公告)日：2006-08-30

申请号：MYPI9903012

申请日：1999-07-16

Applicant: IBM

Inventor： SRI-JAYANTHA SRI MUTHUTHAMBY ,  SHARMA ARUN ,  DANG HIEN PHU ,  KAGAMI NAOYUKI ,  NAKAGAWA YUZO ,  TOKIZONO AKIRA ,  YONEDA ISAO

IPC: G11B21/02 ,  G11B5/596 ,  G11B27/36 ,  G11B21/10 ,  G11B21/21

Abstract: METHODS AND SYSTEMS FOR DETECTING AND CORRECTING FOR UNDESIRABLE VIBRATIONS IMPACTING THE SERVO SYSTEMS (20,2020) IN DATA STORAGE DEVICES (10,2010). A DETECTION TECHNIQUE IS PROVIDED WHEREIN A DETECTION FILTER (40,50,140,240,2040) IS CONFIGURED TO SCAN A POSITION SIGNAL OF THE SERVO SYSTEM ACROSS A RANGE OF FREQUENCIES, AND, AT EACH RESPECTIVE SCANNED FREQUENCY, RECORD AN AMPLITUDE ASSOCIATED THEREWITH. THE RECORDED AMPLITUDES ARE EXAMINED TO DETERMINE WHETHER ANY EXCEED A THRESHOLD, THEREBY LOCATING A PEAK FREQUENCY OF THE VIBRATION. USING THE DETECTED PEAK FREQUENCY OF THE VIBRATION, A CORRECTIVE FILTER IS CONFIGURED TO OPERATE ABOUT THE PEAK FREQUENCY OF VIBRATION, THEREBY REDUCING ITS IMPACT ON THE POSITION SIGNAL IN THE SERVO SYSTEM. OPTIMUM DETECTION AND CORRECTION FILTER STRUCTURE ARE DISCLOSED, AS ARE TECHNIQUES FOR ADDRESSING FILTER STATE VECTORS AS INITIAL CONDITIONS AS THE CORRECTIVE FILTERS ARE REPEATEDLY ENGAGED DURING SUCCESSIVE SETTLE-OUT AND TRACK FOLLOW CYCLES (BETWEEN SEEKS), AS ARE CONTINUOUS ADAPTATION TECHNIQUES FOR CHANGING VIBRATION ENVIRONMENTS.FIGURE 7B

公开(公告)号：JP2003317465A

公开(公告)日：2003-11-07

申请号：JP2002121350

申请日：2002-04-23

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： IKEDO MANABU ,  HOSONO YOSHITAMA ,  KAKIZAKI YOSHITAKA ,  KAGAMI NAOYUKI

IPC: G11B33/14 ,  G11B21/08 ,  G11B21/10 ,  G11B25/04 ,  G11B33/08 ,  G11B33/12

CPC classification number: G11B33/121 ,  G11B25/043 ,  G11B33/08

Abstract: PROBLEM TO BE SOLVED: To improve detection accuracy for vibration in the direction of rotation by eliminating influence in the direction of thickness of a HDD1.
SOLUTION: Acceleration sensors 20a, 20d are arranged in a region formed by connecting screws 22a-22d attaching a circuit substrate 12 to a base 2 and arranged near the screws 22c and 22d.
COPYRIGHT: (C)2004,JPO

Abstract translation: 要解决的问题：通过消除HDD1的厚度方向的影响来提高旋转方向的振动的检测精度。 解决方案：加速度传感器20a，20d布置在通过将电路基板12连接到基座2并布置在螺钉22c和22d附近的螺钉22a-22d形成的区域中。 版权所有（C）2004，JPO

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：JPH04134632A

公开(公告)日：1992-05-08

申请号：JP25546690

申请日：1990-09-27

Applicant: IBM

Inventor： KAGAMI NAOYUKI ,  KUBO HIROAKI ,  OKADA KEIICHI

IPC: G11B7/085

Abstract: PURPOSE: To prevent a miscount of TES by providing a positive or negative peak level comparator, which generates a positive or negative peak pulse when TES exceeds a prescribed level on the positive or the negative side, and a logic circuit which generates an output pulse when the positive or the negative pulse is alternately inputted. CONSTITUTION: TES is inputted in a window comparator 300 for detecting zero cross detection. This comparator 300 outputs a zero cross pulse when TES is within a prescribed range including the zero level of TES, and no zero cross pulse when TES is not. The zero cross pulse is inputted in a pulse discriminator 301, the output of which is inputted in a track count logic 500. The logic 500 functions so as to generate an output pulse only when a prescribed pulse is inputted in a prescribed sequence; namely, it functions as a logic circuit for counting the number of tracks. Under this structure, the number of tracks can be accurately counted even if a fault or a pre-pit exists on the recording surface of an optical disk or if a noise is generated by other causes.

公开(公告)号：JP2002032970A

公开(公告)日：2002-01-31

申请号：JP2000207565

申请日：2000-07-07

Applicant: IBM

Inventor： TOKIZONO AKIRA ,  KAGAMI NAOYUKI ,  UCHIDA HIROSHI ,  KURODA TAKASHI

IPC: G11B21/08 ,  G11B5/012 ,  G11B5/54 ,  G11B5/596 ,  G11B19/04 ,  G11B21/02 ,  G11B21/10 ,  G11B21/22 ,  G11B27/30 ,  G11B27/36

Abstract: PROBLEM TO BE SOLVED: To provide a technique for attempting to maintain a servo lock state and to restore to a normal readout state even when a servo address mark(SAM) can not be detected. SOLUTION: In this device, when the SAM can not be detected, a dummy SAM is generated in timing when a servo lock is not released. When servo control processes in which the dummy SAM is used exceeds a fixed frequency by performing a servo interrupt control normally, the device starts its urgency brake control. In the urgency brake control, the moving direction of an arm is judged and current is made to flow through a VCM(voice coil motor) so that the arm is driven in a reverse direction. Moreover, feedback control is performed by using the output value of a back emf(electromotive face) circuit which is used in a loading/unloading mechanism.

公开(公告)号：JP2000137961A

公开(公告)日：2000-05-16

申请号：JP30917498

申请日：1998-10-29

Applicant: IBM

Inventor： UCHIDA HIROSHI ,  TOKIZONO AKIRA ,  KAGAMI NAOYUKI

IPC: G11B5/55 ,  G11B21/08 ,  G11B21/10

Abstract: PROBLEM TO BE SOLVED: To provide initial value compensation by a writing operation in an initial value compensating method at the time of the head positioning of a hard disk drive even when a distance L between a head starting position and a target position is larger than a specified value. SOLUTION: In the control method of a data recording device for using plural control operation modes during the operation of positioning a reading/ writing head from a starting position to a target position, investigation is made as to the starting time of one control operation mode among the plural control operation modes (S54). Then, in response to the starting time of one control operation mode, determination is made as to whether processing is a writing or reading operation (S55). In response to a writing operation, the processing operation makes investigation as to whether a distance between the starting and target recording positions of the reading/writing head is equal to a specified value or lower and, in response to the determination that the distance between the starting and target recording positions of the reading/writing head is lower than the specified value L1, compensation is performed by an initial value compensating method, and one control mode of the writing operation is executed.