公开(公告)号：JP2000357379A

公开(公告)日：2000-12-26

申请号：JP2000170006

申请日：2000-06-07

Applicant: IBM

Inventor： OGASAWARA KENJI ,  YANAGISAWA HIROSHI ,  KOBAYASHI KEIJI

IPC: G11B21/10

Abstract: PROBLEM TO BE SOLVED: To enable eliminating needless spaces between data recording tracks by reading a servo pattern by a positioned read/write head, detecting amplitude of an generated output signal, and detecting that it has become a specific value of amplitude of an output signal from a positioning head. SOLUTION: It is detected that a servo pattern is read out by a read/write head being moving and its output signal value is made 50-Gw/2% of amplitude of an output signal generated by a positioned read/write head. Then, Gw is a scheduled gap width between data recording tracks. Reduction of amplitude of an output signal to 50-Gw/2% indicates that a head is moved from a prescribed position by (Hw+Gw)/2(Hw is head width), when it is not decreased, it is examined whether a head reaches a crush-stop of the outside or not.

公开(公告)号：JPH1125627A

公开(公告)日：1999-01-29

申请号：JP17443597

申请日：1997-06-30

Applicant: IBM

Inventor： KITAZAKI NOBUYUKI ,  AMANO YOSHIRO ,  OGASAWARA KENJI ,  UENO SHINJI

IPC: G11B21/12 ,  G11B19/00

Abstract: PROBLEM TO BE SOLVED: To surely unload a head slider. SOLUTION: A transistor Tr5 is made to be in ON. When a main power source Vdd is turned OFF at a time t1, transistors Tr1, Tr2 and a diode D1 are turned OFF and the level of a control signal Ret becomes higher than threshold voltages Vth of transistors Tr3, Tr4 to turn transistors Tr3, Tr4 OFF. Moreover, a capacitor C1 starts a discharge. A control signal InRet changes to 'L' level and a control signal OutRet does not change while being kept in 'L'. As a result, an IR(inner retract) driver 133aa makes the VCM(voice coil motor) current of a negative polarity flow through a voice coil 5 to preliminarily move a head arm to a direction opposite to an unload direction. Next, when it becomes a time t2 and the level of the control signal Ret becomes the level of not larger than the threshold voltages Vth, the control signals InRet and OutRet both change to 'H' and the IR driver 13aa stops the operation and an OR(outer retract) driver 13ab reverses the moving direction of the head arm by making the VCM current of a possitive polarity flow through the voice coil 5.

公开(公告)号：JPH1116136A

公开(公告)日：1999-01-22

申请号：JP17156997

申请日：1997-06-27

Applicant: IBM

Inventor： YONEDA ISAO ,  UCHIIKE HIROSHI ,  UENO SHINJI ,  OGASAWARA KENJI

IPC: G11B21/02 ,  G11B5/40 ,  G11B5/54 ,  G11B19/04 ,  G11B21/12

Abstract: PROBLEM TO BE SOLVED: To prevent the occurrence of an accidental unloading. SOLUTION: The head slider having a converter head is mounted on a head arm. If the arm is rotated, the slider is unloaded from a disk. The retracting position is located at the boundary section within the rotating range of the arm. If the slider is normally unloaded to the retracting position, the arm does not move even though a driving force is applied to the head arm in an unloading direction. Then, an unloading is executed in a step S2, a position confirmation driving force is applied to the arm in the unloading direction, the moving speed of the slider is detected in a step S4 and discrimination is made in a step 5 to determine whether the slider is unloaded to the retracting position or not based on the movement speed. If the slider is not unloaded at the retracting position, a re-unloading is executed in a step S7 to move the slider back to the retracting position.

公开(公告)号：JPH097148A

公开(公告)日：1997-01-10

申请号：JP24283295

申请日：1995-09-21

Applicant: IBM

Inventor： NAKAMURA TAKASHI ,  YONEDA ISAO ,  YOKOE YUJI ,  TSUNAKO KAZUJI ,  HARAKO FUJIO ,  SUDA KATSUMI ,  NAKAJIMA MICHIO ,  OGASAWARA KENJI

IPC: G11B5/60 ,  G11B19/04 ,  G11B19/20 ,  G11B23/50

Abstract: PROBLEM TO BE SOLVED: To eliminate an error due to thermal asperity by detecting a read defect on a data recording surface, varying the rotating speed of a disk and making a signal transducer which has decreased in flotation quantity collide, and breaking a projection as the thermal asperity. SOLUTION: Once the signal transducer 20 equipped with an air bearing surface(ABS) 44 and a magneto-resistive(MR) element 42 detects the projection 52 as the thermal asperity of the magnetic disk 18, the rotating speed of the disk is reduced. The ABS 44 of the signal transducer 20 which has decreased in flotation quantity by the speed reduction collides against the projection 52, which is broken, thereby eliminating the read error due to the thermal asperity.

公开(公告)号：JPH08263815A

公开(公告)日：1996-10-11

申请号：JP23191294

申请日：1994-09-27

Applicant: IBM

Inventor： OGASAWARA KENJI ,  YANAGISAWA HIROSHI ,  KURACHI KOJI

IPC: G11B21/10 ,  G11B5/55 ,  G11B5/596 ,  G11B5/53

Abstract: PURPOSE: To accurately position write and read magnetic heads by forming plural data tracks in a prescribed direction and recording 1st to 4th burst patterns. CONSTITUTION: Plural burst pattern recording areas 50 are formed radially along a radial direction of a disk 18 and remaining areas are used for a data track area 52. A test pattern is formed on the areas 50 by recording data in a prescribed pattern. The test patterns are made up of four burst pattern strings A-D formed radially on the disk 18. In each of the data recording areas for each burst pattern string, an interval between the adjacent areas along the radial direction of the disk 18 is selected equal to a pitch P of the data track areas 54.

公开(公告)号：JP2004030777A

公开(公告)日：2004-01-29

申请号：JP2002185284

申请日：2002-06-25

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International Business Maschines Corporation

Inventor： KITAZAKI NOBUYUKI ,  YANASE HIROBUMI ,  TAKECHI ATSUSHI ,  OGASAWARA KENJI ,  IKEDA MASAOMI

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

CPC classification number: G11B5/59633 ,  G11B21/02

Abstract: PROBLEM TO BE SOLVED: To record a servo pattern of track pitch individually corresponding to characteristics (write width, read width) of a head onto a recording medium of the data storage device. SOLUTION: This device is provided with a disk 20 in which TPI ID (pitch information) indicating a track pitch is recorded in the prescribed region and a head reading the TPI ID by scanning this disk and performing reading and writing of data for the disk 20 by being seek controlled based on this TPI ID. This TPI ID is recorded in a TOI ID embedded region 23 provided at an outer periphery of a data region 21 of the disk 20 as a part of a servo pattern 24. COPYRIGHT: (C)2004,JPO

公开(公告)号：JPH1125626A

公开(公告)日：1999-01-29

申请号：JP17184997

申请日：1997-06-27

Applicant: IBM

Inventor： YONEDA ISAO ,  UCHIIKE HIROSHI ,  UENO SHINJI ,  OGASAWARA KENJI ,  AOKI YOSHIHIKO ,  SAI FUMINORI

IPC: G11B21/02 ,  G11B5/54 ,  G11B19/04 ,  G11B19/28 ,  G11B21/12 ,  G11B19/12

Abstract: PROBLEM TO BE SOLVED: To provide a disk drive device, a load/unload device and its control method performing stable speed control and improving reliability in data. SOLUTION: The disk drive device 10 is provided with a VCM(voice coil motor) spindle driver 12 rotation driving a disk 11, a magnetic head 13, an actuator mechanism 14 moving a head slider having the magnetic head 13 over the magnetic disk 11 surface and to a retreat position, a lamp block 15 and a CPU/HDC (hard disk controller) 16 controlling a speed of an actuator, controlling calibration detecting offset and dynamic range of an AD(analog/digital) converter prior to this speed control and controlling operation such as read-out/ write-in, etc., of data for the disk 11. Then, the device 10 increases a rectangular current value applied to a voice coil while successively changing a code, and measures the offset from the value of the AD converter at every current value, and decides it is a nonlinear area when a difference between the expected value and the measured value of the AD converter becomes a prescribed value or above to measure the dynamic range.

公开(公告)号：JPH10334626A

公开(公告)日：1998-12-18

申请号：JP12853997

申请日：1997-05-19

Applicant: IBM

Inventor： OGASAWARA KENJI ,  SAI FUMINORI ,  UENO SHINJI ,  YONEDA ISAO

IPC: G11B5/02 ,  G11B5/60 ,  G11B21/08 ,  G11B21/12 ,  G11B21/21 ,  G11B23/50

Abstract: PROBLEM TO BE SOLVED: To prevent the adhesion of a head/slider assembly to the surface of a magnetic recording disc when the air pressure in the using environment is lowered. SOLUTION: When this method is used, a head flies on a disc 1, a head supporting arm 4 is moved along the diagonal direction of the disc 1 and a disc driving device positions the head to one of the cylinder positions of the disc 1. In this case, the air pressure at the part where the device set is detected during the power-on-reset period. The value is compared with a threshold value. Whether the operation for lowering the flying height of the head to the height lower than height for operation during the reading/writing period is prohibited or is not judged. In the detection, the current required for retaining the head at the selected cylinder position is detected and compared with the reference current value for retaining the head at the cylinder position at the reference air pressure. The value of the difference is generated and compared with the threshold value. The step for generating the information is included.

公开(公告)号：JPH07211000A

公开(公告)日：1995-08-11

申请号：JP31878093

申请日：1993-12-17

Applicant: IBM

Inventor： KIGAMI YUJI ,  YOKOE YUJI ,  NUMATA TSUTOMU ,  NAKAMURA TAKASHI ,  OGASAWARA KENJI ,  KURACHI KOJI ,  MATSUI TAKAO ,  OKADA MAYUMI

IPC: G11B20/10 ,  G11B5/012 ,  G11B5/09 ,  G11B19/02 ,  G11B20/12 ,  G11B20/18 ,  G11B27/10

Abstract: PURPOSE: To refer to information on constitution or the like for respective sectors and to increase information quantity by permitting a hard disk controller to calculate an absolute block address to calculate a physical position in a specified zone and executing a seek operation based on the physical position. CONSTITUTION: The hard disk controller HDC 30 refers to a defect list D-LST and calculates the absolute block address ABA by all the sectors, which corresponds to a designated logic block address LBA. When a host computer requests the reading of the sectors from #L to #M in the address LBA, the absolute block address ABA is calculated to be #N. When the belonging zone Zn is set to be #Z, the min address ABA is to be MIN-ABBA(#Z) and a min cylinder is MIN-CYL(#Z), the address ABA is shown by an expression. Then, #ZN is set to be the serial numbers of the sectors. The head is switched and the seek operation is executed based on the physical position which is thus calculated.