公开(公告)号：EP0929067A1

公开(公告)日：1999-07-14

申请号：EP99100195.9

申请日：1999-01-07

申请人： Hitachi, Ltd.

发明人： Nishida, Yasutaka ,  Hamaguchi, Takehiko ,  Takano, Hisashi ,  Ide, Hiroshi ,  Sawaguchi, Hideki, Center for magn.research 0401 ,  Tomiyama, Futoshi

IPC分类号： G11B19/04 ,  G11B5/596

CPC分类号： G11B19/04 ,  G11B5/596

摘要： When the amount of position error PE of a magnetic head meets the condition of Ewf>PE>=Eww for two threshold values Ewf and Eww meeting Ewf>Eww, the track is registered in the track information table as a track requiring rewrite and the tracks on both sides neighboring to the track are temporarily write-inhibited. The data of the track is rewritten on another track later so as to maintain the data.
By doing this, the offtrack of the recording track can be made smaller without sacrifice of the access speed and the occurrence probability of write fault can be reduced. Furthermore, the reliability of a magnetic disk apparatus can be improved.

摘要翻译： 当磁头的位置误差PE的数量满足Ewf> PE> = Eww的两个阈值Ewf和Eww满足Ewf> Eww的条件时，轨道作为需要重写的轨迹被登记在轨道信息表中，并且轨道 在与轨道相邻的两侧临时禁止写入。 轨道的数据稍后重写在另一个轨道上，以便维护数据。 通过这样做，可以在不牺牲访问速度的情况下使记录轨道的后部变小，并且可以减少写入故障的发生概率。 此外，可以提高磁盘装置的可靠性。

公开(公告)号：EP0517137A3

公开(公告)日：1993-07-14

申请号：EP92109188.0

申请日：1992-06-01

申请人： HITACHI, LTD.

发明人： Suzuki, Hiroshi ,  Todokoro, Hideo ,  Takano, Hisashi ,  Shinada, Hiroyuki

IPC分类号： G11B5/187 ,  G11B5/31 ,  G11B5/39 ,  G11B5/012 ,  G11B5/02 ,  G11B5/596

CPC分类号： G11B5/3967 ,  G11B5/02 ,  G11B5/1871 ,  G11B5/3116 ,  G11B5/313 ,  G11B5/3163 ,  G11B5/596 ,  G11B5/59633 ,  G11B5/59683

摘要： A magnetic head is disclosed which forms longitudinal magnetic field distribution (namely, spatial distribution with respect to the magnetic field in a longitudinal recording direction) made up of a narrow region corresponding to a narrow track width and a broad region for reinforcing the narrow portion. Such spatial distribution can be realized by spacing broad surface portions on both sides of that central surface portion of pole face which defines the narrow track width, apart from the air bearing surface of the magnetic head for a recording medium. Alternatively, the spatial distribution may be realized by making the magnetic path of the magnetic head of a plurality of materials (8, 9) different in saturated magnetic flux density from each other, or by forming main magnetic poles (10, 11) for defining the small track width, independently of magnetic poles (12, 13) for reinforcing a magnetic field formed by the main magnetic poles.

公开(公告)号：EP0452876A3

公开(公告)日：1992-03-18

申请号：EP91106043.2

申请日：1991-04-16

申请人： HITACHI, LTD.

发明人： Matsuda, Yoshibumi ,  Futamoto, Masaaki ,  Kugiya, Fumio ,  Miyamura, Yoshinori ,  Nakao, Takeshi ,  Takano, Hisashi ,  Akagi, Kyo ,  Suzuki, Mikio ,  Ouchi, Yasuhide

IPC分类号： G11B5/82

CPC分类号： B82Y10/00 ,  G11B5/09 ,  G11B5/5526 ,  G11B5/59633 ,  G11B5/74 ,  G11B5/743 ,  G11B5/82 ,  G11B5/855 ,  Y10S428/90

摘要： It is disclosed that a longitudinal magnetic recording medium and apparatus has recording sections having longitudinal magnetic films (3) magnetically isolated in a recording direction. The magnetically isolated recording sections can record a single bit each so that the longitudinal magnetic recording medium can remove the irregular domain boundary of its own caused on boundaries of magnetization reversals in the recording direction. This can improve the signal-to-media noise ratio to a great extent in writing and reading.

公开(公告)号：EP0472047A3

公开(公告)日：1992-03-11

申请号：EP91113218.1

申请日：1991-08-06

申请人： HITACHI, LTD.

发明人： Matsuda, Yoshibumi ,  Futamoto, Masaaki ,  Miyamura, Yoshinori ,  Takagaki, Tokuho ,  Takano, Hisashi ,  Kugiya, Fumio ,  Nakao, Takeshi ,  Akagi, Kyo ,  Suzuki, Mikio ,  Fukuoka, Hirotsugu ,  Munemoto, Takayuki

IPC分类号： G11B5/66 ,  G11B5/716

CPC分类号： G11B5/66 ,  G11B5/64 ,  Y10S428/90 ,  Y10T428/24942 ,  Y10T428/2495

摘要： In a magnetic recording medium, both the saturation induction and the coercive force of a magnetic film increase towards a surface of the recording medium. Information can be recorded with a linear recording density higher than 50 kFCI even with a spacing around 0.2 µm.

公开(公告)号：EP0917134A3

公开(公告)日：2000-09-13

申请号：EP98121193.1

申请日：1998-11-13

申请人： Hitachi, Ltd.

发明人： Maruyama, Yohji ,  Tomiyama, Futoshi ,  Hamaguchi, Takehiko ,  Takano, Hisashi

IPC分类号： G11B5/596 ,  G11B21/10

CPC分类号： B82Y25/00 ,  B82Y10/00 ,  G11B5/012 ,  G11B5/3948 ,  G11B5/5526 ,  G11B5/5534 ,  G11B5/58 ,  G11B5/59605 ,  G11B5/59611 ,  G11B5/59622 ,  G11B5/59644 ,  G11B5/59683 ,  G11B2005/3996

摘要： There is provided a magnetic recording apparatus comprising at least a magnetic head (12) and a positioning system (13-15) for the magnetic head (12), which has a circuit (18,19) for separately detecting a positive pulse amplitude and a negative pulse amplitude of a reproduction signal provided in an electric circuit of the magnetic recording apparatus, calculates an off-track value of the magnetic head (12) by executing an arithmetic operation on the basis of the two kinds of amplitude values and generates a positioning signal.

摘要翻译： 提供了一种磁记录设备，包括至少一个用于磁头（12）的磁头（12）和定位系统（13-15），其具有用于分别检测正脉冲幅度的电路（18,19）和 在磁记录设备的电路中提供的再现信号的负脉冲幅度，通过基于两种幅度值执行算术运算来计算磁头（12）的偏离磁道值，并且生成 定位信号。

公开(公告)号：EP0472047B1

公开(公告)日：1997-10-29

申请号：EP91113218.1

申请日：1991-08-06

申请人： HITACHI, LTD.

发明人： Matsuda, Yoshibumi ,  Futamoto, Masaaki ,  Miyamura, Yoshinori ,  Takagaki, Tokuho ,  Takano, Hisashi ,  Kugiya, Fumio ,  Nakao, Takeshi ,  Akagi, Kyo ,  Suzuki, Mikio ,  Fukuoka, Hirotsugu ,  Munemoto, Takayuki

IPC分类号： G11B5/66 ,  G11B5/716

CPC分类号： G11B5/66 ,  G11B5/64 ,  Y10S428/90 ,  Y10T428/24942 ,  Y10T428/2495

公开(公告)号：EP0452876B1

公开(公告)日：1994-08-31

申请号：EP91106043.2

申请日：1991-04-16

申请人： HITACHI, LTD.

发明人： Matsuda, Yoshibumi ,  Futamoto, Masaaki ,  Kugiya, Fumio ,  Miyamura, Yoshinori ,  Nakao, Takeshi ,  Takano, Hisashi ,  Akagi, Kyo ,  Suzuki, Mikio ,  Ouchi, Yasuhide

IPC分类号： G11B5/82

CPC分类号： B82Y10/00 ,  G11B5/09 ,  G11B5/5526 ,  G11B5/59633 ,  G11B5/74 ,  G11B5/743 ,  G11B5/82 ,  G11B5/855 ,  Y10S428/90

公开(公告)号：EP0930613A1

公开(公告)日：1999-07-21

申请号：EP98124874.3

申请日：1998-12-30

申请人： Hitachi, Ltd.

发明人： Ide, Hiroshi ,  Tomiyama, Futoshi ,  Nishida, Yasutaka ,  Hamaguchi, Takehiko ,  Takano, Hisashi ,  Maruyama, Yohji ,  Nakamura, Atsushi ,  Sawaguchi, Hideki c/oUniversity of California

IPC分类号： G11B19/04 ,  G11B5/596

CPC分类号： G11B19/04 ,  G11B5/596

摘要： An information storage apparatus having a disk medium 3 with data recording areas 203 along a plurality of tracks concentrically arranged, a head 4 for recording and reproducing data on tracks of the disk medium, an actuator 5 for moving the head to a desired track among the plurality of tracks, and an electric circuit 7 for controlling recording and reproducing and for detecting the distance from a recorded magnetization pattern on the adjacent tracks in the radial direction by detecting already recorded signals of adjacent tracks during data recording. By use of this constitution, even if the track density is increased, the upper limit of the threshold value setting range in the function for preventing from offtrack recording of the information storage apparatus can be increased and a high track density of the information storage apparatus can be easily realized.

摘要翻译： 一种信息存储装置，具有一个磁盘介质3，具有沿同心排列的多个轨道的数据记录区域203，用于在磁盘介质的磁道上记录和再现数据的磁头4;用于将磁头移动到所需磁道 多个磁道，以及电路7，用于通过在数据记录期间检测相邻轨道的已经记录的信号来控制记录和再现并且通过在数据记录期间检测相邻轨道的已记录的信号来检测与径向上的相邻轨道上的记录的磁化模式的距离。 通过使用这种结构，即使磁道密度增大，也可以提高防止信息存储装置的高速记录功能的阈值设定范围的上限，信息存储装置的高磁道密度可以 容易实现

公开(公告)号：EP0472047A2

公开(公告)日：1992-02-26

申请号：EP91113218.1

申请日：1991-08-06

申请人： HITACHI, LTD.

发明人： Matsuda, Yoshibumi ,  Futamoto, Masaaki ,  Miyamura, Yoshinori ,  Takagaki, Tokuho ,  Takano, Hisashi ,  Kugiya, Fumio ,  Nakao, Takeshi ,  Akagi, Kyo ,  Suzuki, Mikio ,  Fukuoka, Hirotsugu ,  Munemoto, Takayuki

IPC分类号： G11B5/66 ,  G11B5/716

CPC分类号： G11B5/66 ,  G11B5/64 ,  Y10S428/90 ,  Y10T428/24942 ,  Y10T428/2495

摘要： In a magnetic recording medium, both the saturation induction and the coercive force of a magnetic film increase towards a surface of the recording medium. Information can be recorded with a linear recording density higher than 50 kFCI even with a spacing around 0.2 µm.

摘要翻译： 在磁记录介质中，磁性膜的饱和感应和矫顽力都朝向记录介质的表面增加。 信息可以以高于50kFCI的线性记录密度记录，即使间距约为0.2μm。

公开(公告)号：EP0452846A3

公开(公告)日：1992-01-29

申请号：EP91105963.2

申请日：1991-04-15

申请人： HITACHI, LTD.

发明人： Takano, Hisashi ,  Koyama, Naoki ,  Tanabe, Hideo ,  Moriwaki, Eijin ,  Yuito, Isamu ,  Shiiki, Kazuo ,  Ohnishi, Tsuyoshi ,  Ishitani, Tohru ,  Kobayashi, Toshio ,  Todokoro, Hideo ,  Ishikawa, Chiaki, (nee Saka)

IPC分类号： G11B5/31 ,  G11B5/39 ,  G11B5/60

CPC分类号： G11B5/3903 ,  G11B5/112 ,  G11B5/1278 ,  G11B5/1871 ,  G11B5/3103 ,  G11B5/3106 ,  G11B5/3116 ,  G11B5/3143 ,  G11B5/3163 ,  G11B5/3967

摘要： In a composite magnetic head comprising a magnetoresistive read head (10) including a magnetic thin film having a magnetoresistive effect and soft magnetic members interposing the soft magnetic film between them through a non-magnetic insulation layer, an induction type write head (11) including poles formed in a moving direction of a medium and a conductor crossing the poles, and disposed in the proximity of the magnetoresistive head, and a substrate (5) supporting these heads, the present disclosure describes a composite magnetic head characterized in that part of a floating surface inclusive of the magnetic head constituent members has recesses (7, 8) and the read/write operations to and from the medium are effected by the portion interposed by these recesses.