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公开(公告)号：JPH04134729A
公开(公告)日：1992-05-08
申请号：JP25546790
申请日：1990-09-27
Applicant: IBM
Inventor： KAGAMI NAOYUKI , KUBO HIROAKI , OKADA KEIICHI
Abstract: PURPOSE: To constantly perform a seek operation properly regardless of a seek speed by providing a means for controlling the control gain of a focus control means. CONSTITUTION: An optical head 10 is composed of a coarse actuator 20 and a fine actuator 30, with the coarse actuator 20 driven in the direction of a seek operation by a coarse actuator VCM(voice coil motor) 24. In addition, the coarse actuator 20 is provided with a relative position (RPE) detecting sensor 25, focus error signal(FES) detecting sensor 27, and tracking error signal(TES) detecting sensor 29. Then, with a highspeed seek operation performed for a certain period after the commencement of the seek operation, the control gain of the focus control means during this period is made the same value as the control gain in the period of a track following operation; with the seek operation nearing the completion, a control signal is imparted from a controller 200 to a gain control means 300, lowering the control gain of the focus control means to a prescribed value. Thus, the control of the seek operation can be constantly performed properly.
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公开(公告)号：JP2002260355A
公开(公告)日：2002-09-13
申请号：JP2001052643
申请日：2001-02-27
Applicant: IBM
Inventor： HATTORI RYOHEITA , MATSUBARA NOBUYA , KOKUBO TETSUYA , UMEMURA KAORU , KAGAMI NAOYUKI
Abstract: PROBLEM TO BE SOLVED: To improve the reliability of a burst pattern inspection in a hard disk drive. SOLUTION: The writing test of test pattern data on a track boundary is added besides the writing of a test pattern in a SAT test at the track center conventionally performed and the inspection of burst patterns (A, B patterns) by the writing test at that time. Thereby, a highly sensitive inspection of C and D burst patterns sensitive to a PES signal can be conducted on the track boundary.
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公开(公告)号：JP2001101784A
公开(公告)日：2001-04-13
申请号：JP27332799
申请日：1999-09-27
Applicant: IBM
Inventor： IKEDO MANABU , YUZUBA AKINORI , KAGAMI NAOYUKI
Abstract: PROBLEM TO BE SOLVED: To provide a load/unload type disk driver that can control motor revolution with high accuracy after a head is loaded in the load/unload type disk driver. SOLUTION: Since a slew rate is switched in cross-reference with loading/ unloading of the head, the operating noise sound of the motor can be reduced at a steady-state rotation and the rotational speed can be controlled with high accuracy on the occurrence of a load fluctuation of the spindle motor due to loading of the head.
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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
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.
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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
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.
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Patent Agency Ranking
公开(公告)号：JPH1145516A
公开(公告)日：1999-02-16
申请号：JP20015897
申请日：1997-07-25
Applicant: IBM
Inventor： HATANO AKIRA , KAGAMI NAOYUKI , MATSUBARA NOBUYA
IPC: G11B5/09 , G06F11/267 , G11B20/12 , G11B20/18
Abstract: PROBLEM TO BE SOLVED: To drastically reduce unnecessary flags and to reduce defective disks by preventing errors to be generated at random from being flagged. SOLUTION: A cyclic redundant check CRC is performed on read data by a CRC circuit 20, and a data error is detected by an ECC circuit 21. At this time, a surface analyzation test SAT is executed by a calculator 16 in such an algorithm that when error generation positions in the same sector are apart from one another by more than a prescribed distance, no flagging is carried out. In other words, a data is read out of a target data area, and an error position is detected by the ECC circuit 21 to check distances of the previous and present error portions respectively, and if there distances are closer values than the prescribed distance perceptively, checking the distance is performed a prescribed number of times, and if the closer state is more than prescribed criteria, flagging is performed. Consequently, flags on errors caused at random by noise are drastically reduced, and errors required for flags are certainly flagged.
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公开(公告)号：JPH08124373A
公开(公告)日：1996-05-17
申请号：JP26513194
申请日：1994-10-28
Applicant: IBM
Inventor： NAKAGAWA YUZO , SATO KIYOSHI , KITABORI HIRONORI , KAGAMI NAOYUKI
Abstract: PURPOSE: To minimize the size of a printed board while increasing the degree of freedom of a spindle motor. CONSTITUTION: The connector 52 of an interface cable is disposed oppositely to a spindle motor 18 and a printed board 50 has such size as not touching the height of the spindle motor 18. Consequently, the degree of freedom is increased in the arrangement of the spindle motor 18. The distance between the connector 52 of the interface cable and the connector of a preamplifier mounted on the printed board 50 is short. This structure can minimize the size of the printed board 50.
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公开(公告)号：JPH05234099A
公开(公告)日：1993-09-10
申请号：JP34333591
申请日：1991-12-25
Applicant: IBM
Inventor： KAGAMI NAOYUKI , KUBO HIROAKI
IPC: G11B7/085
Abstract: PURPOSE: To execute scanning with high reliability at high speed by providing a means for indicating the number of tracks from the present to a target and driving a precise actuator, only when the number of the tracks is equal to below than the prescribed one. CONSTITUTION: A microprocessor and logic 22 inspect the contents of a track counter 21. When the residual number is equal to or blow a prescribed value, a long/short scanning control line 200 is made to be a short scanning state. A change-over equipment 201 is connected to the side of a course servo controller 14 and the change-over equipment 202 is connected to the side of an integration equipment 105. The contents of the counter 21 is inputted to a reference speed generator and reference speed, corresponding to the number of the residual tracks is given to a comparator 104. In the mean time, the signal of a TES sensor 7 is converted into the traveling speed of an optical point 23 by a differential equipment 102 and a rectifying equipment 103 and compared with a reference value by the comparator 104. Difference is adopted as a position difference signal PES with the integration equipment 105. An actuator 3 is driven, based on the PES with a servo controller 12 and a VCM driver 13. A head 1 follows and moves so as to permit the position difference of a lens 24 to be zero. The optical point 23 reaches the target, and the control line becomes a position control state.
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公开(公告)号：JPH04134682A
公开(公告)日：1992-05-08
申请号：JP25546590
申请日：1990-09-27
Applicant: IBM
Inventor： KAGAMI NAOYUKI , KUBO HIROAKI , TAKEKOSHI MAKOTO
Abstract: PURPOSE: To surely recover a track follow-up operation in a short time by carrying out a seek operation in which a track separated by a prescribed distance is made a target track, in response to a failed detection of the track follow-up operation. CONSTITUTION: With a track follow-up operation failing, the amplitude of a tracking error signal(TES) expands, with a TES error generated and guided to a controller 200, so that the failure of the track follow-up operation is detected. In this case, a seek operation is carried out by setting a target position at five tracks away towards the inside if the present position is near the outer side of an optical disk, and at five tracks away towards the outside if near the inner side. With the seek operation performed, the moving speed of a beam is controlled along a speed profile and, as a result, the beam gains such a speed as capable of being transferred to a follow-up operation at the point of time after moving five tracks. Thus, since a servo control is not turned off after the detection of the failure of the track follow-up operation, its recovery is surely performed.
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公开(公告)号：DE69117126T2
公开(公告)日：1996-10-02
申请号：DE69117126
申请日：1991-09-24
Applicant: IBM
Inventor： KAGAMI NAOYUKI , KUBO HIROAKI , OKADA KEIICHI
IPC: G11B7/085
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