公开(公告)号：WO1998002878A1

公开(公告)日：1998-01-22

申请号：PCT/JP1997002420

申请日：1997-07-11

Applicant: HITACHI MAXELL, LTD. ,  SANYO ELECTRIC CO., LTD. ,  AWANO, Hiroyuki ,  SHIRAI, Hiroshi ,  YOSHIHIRO, Masafumi ,  OONUKI, Satoru ,  OHTA, Norio ,  SHIMAZAKI, Katsusuke ,  NAGAI, Nobuyuki ,  SUMI, Satoshi ,  YAMAGUCHI, Atsushi

Inventor： HITACHI MAXELL, LTD. ,  SANYO ELECTRIC CO., LTD.

IPC: G11B11/10

CPC classification number: G11B11/10584 ,  G11B11/1051 ,  G11B11/10515 ,  G11B11/10554 ,  G11B11/10586 ,  G11B11/10595 ,  G11B27/19 ,  G11B27/3027

Abstract: Reproducing light (13) is applied to a magneto-optical recording medium (11) and only a minute magnetic domain (313b) which is smaller than a half of the spot diameter of the reproducing light (13) is selected by a gate layer (17) and transferred onto a magnetic domain expanding/reproducing layer (3) and the transferred magnetic domain is expanded by an expanding/reproducing magnetic field (411) which is an alternating magnetic field. A large reproducing signal output is obtained from the expanded magnetic domain (419) and the minute magnetic domain can be reproduced with a high resolution and a high S/N. The expanded magnetic domain (419) is contracted by a contracting/reproducing magnetic field (415) which is an alternating magnetic field. The thickness of the gate layer (17) is larger than the thickness of the magnetic wall of the magnetic domain of the gate layer (17). A nonmagnetic layer may be used instead of the gate layer (17).

Abstract translation: 再现光（13）被施加到磁光记录介质（11），并且只有小于再现光（13）的光点直径的一半的微小磁畴（313b）由栅极层（ 17）并转移到磁畴扩展/再现层（3）上，并且通过作为交变磁场的扩展/再现磁场（411）来扩展转移的磁畴。 从扩展磁畴（419）获得大的再现信号输出，并且可以以高分辨率和高S / N再现微小磁畴。 扩展的磁畴（419）由作为交变磁场的收缩/再现磁场（415）收缩。 栅极层（17）的厚度大于栅极层（17）的磁畴的磁壁的厚度。 可以使用非磁性层代替栅极层（17）。

公开(公告)号：WO1997022969A1

公开(公告)日：1997-06-26

申请号：PCT/JP1996003716

申请日：1996-12-20

Applicant: HITACHI MAXELL, LTD. ,  OHNUKI, Satoru ,  OHTA, Norio ,  SHIMAZAKI, Katsusuke ,  YOSHIHIRO, Masafumi ,  TAKAO, Hiroki ,  WATANABE, Hitoshi

Inventor： HITACHI MAXELL, LTD.

IPC: G11B11/10

CPC classification number: G11B11/10515 ,  G11B11/10584 ,  G11B11/10593

Abstract: A magneto-optic recording medium (11) includes a second auxiliary magnetic film (4), a first auxiliary magnetic film (5) and a magneto-optic recording film (6) on a substrate (1). The auxiliary magnetic films (4 and 5) change from in-plane magnetization to vertical magnetization at critical temperatures TCR1 and TCR2. Since they have the relation TCR1 > TCR2, the magnetic domain transferred from the magneto-optic recording film (6) to the first auxiliary magnetic film (5) at the time of reproduction is expanded further greater in diameter and is transferred to the second auxiliary magnetic film (4) when the temperature profiles of the auxiliary magnetic films inside an optical spot are utilized. The magnetic domain of the magneto-optic recording film (6) can be expanded and transferred, too, by means of magnetostatic coupling by using a non-magnetic film (9) in place of the first auxiliary magnetic film (5). Pulse reproduction light subjected to power modulation in synchronism with a reproduction clock can be used at the time of reproduction. Even when a very small magnetic domain is recorded, the intensity of an amplified reproduction signal can be detected and excellent C/N can be obtained.

Abstract translation: 磁光记录介质（11）在基板（1）上包括第二辅助磁膜（4），第一辅助磁膜（5）和磁光记录膜（6）。 在临界温度TCR1和TCR2，辅助磁膜（4和5）从面内磁化转变为垂直磁化。 由于它们具有关系TCR1> TCR2，所以在再现时从磁光记录膜（6）转移到第一辅助磁膜（5）的磁畴的直径进一步扩大并被转移到第二辅助 利用光斑内的辅助磁性膜的温度分布时的磁性膜（4）。 也可以通过使用非磁性膜（9）代替第一辅助磁性膜（5）的静磁耦合来扩展和转移磁光记录膜（6）的磁畴。 在再现时可以使用经受与再现时钟同步的功率调制的脉冲再现光。 即使记录非常小的磁畴，也可以检测出放大的再现信号的强度，可以获得优异的C / N。

公开(公告)号：WO1997003439A1

公开(公告)日：1997-01-30

申请号：PCT/JP1996001938

申请日：1996-07-12

Applicant: HITACHI MAXELL, LTD. ,  SHIMAZAKI, Katsusuke ,  OHTA, Norio ,  ITO, Akiyoshi ,  NAKAGAWA, Katsuji ,  INOUE, Kazuko

Inventor： HITACHI MAXELL, LTD.

IPC: G11B11/10

CPC classification number: G11B11/10508 ,  G11B11/10515 ,  G11B11/10586

Abstract: A magneto-optical recording medium and a method for recording and reproduction thereon are provided in order to reproduce information recorded by multi-valued recording at a high S/N ratio. Disclosed is a magneto-optical recording medium including two magnetic layers capable of four-valued recording based on four combined magnetization states. Magnitudes of reproduction signals concerning the four magnetization states, obtained upon reproduction at a wavelength lambda 1, are different from those obtained upon reproduction at a wavelength lambda 2. The two magnetic layers, on which a signal (a) is recorded, are irradiated with light beams having the wavelengths lambda 1 and lambda 2 repectively. Signals (d), (e) reproduced from respective reflected light beams are sliced by using at least one slice level to obtain two-valued or higher multi-valued reproduction signals respectively. The two-valued or higher multi-valued reproduction signals (f), (g) from the respective wavelengths are mutually subjected to logical operation to reproduce recorded information (i).

Abstract translation: 提供磁光记录介质及其上的记录和再现方法，以便以高S / N比再现通过多值记录记录的信息。 公开了一种包括基于四个组合磁化状态能够进行四值记录的两个磁性层的磁光记录介质。 关于在波长λ1再现时获得的四种磁化状态的再现信号的幅度与在波长λ2再现时获得的不同。将记录有信号（a）的两个磁性层照射 分别具有波长λ1和λ2的光束。 通过使用至少一个限幅电平对从各反射光束再现的信号（d），（e）进行分片，以分别获得二值或更高的多值再现信号。 来自各个波长的两值或更高的多值再生信号（f），（g））相互进行逻辑运算以再现记录信息（i）。

公开(公告)号：WO1997005607A1

公开(公告)日：1997-02-13

申请号：PCT/JP1996002157

申请日：1996-07-31

Applicant: HITACHI MAXELL, LTD. ,  OHNUKI, Satoru ,  OHTA, Norio ,  SHIMAZAKI, Katsusuke ,  YOSHIHIRO, Masafumi ,  SUGIYAMA, Toshinori ,  OHNUKI, Takeshi

Inventor： HITACHI MAXELL, LTD.

IPC: G11B07/24

CPC classification number: G11B23/0316 ,  G11B11/1058 ,  G11B11/10584 ,  G11B23/0307

Abstract: An optical head (67) and a magnetic head (65) for magnetooptical disk recording/reproduction are placed between sliders (66a to 66d) that serve to form narrow air gaps (68) between the heads and a disk. When air flows in directions tangential to tracks because of the rotation of a disk (61), the pressure in the air gaps increases, and the disk surface can be kept at a predetermined position so that the pressure in the vertical direction of the disk (61) becomes uniform. This construction is effective for a thin disk having a substrate thickness of not greater than 0.85 mm. A disk cartridge (101) effective for a thin disk includes a roller member (111) which engages with the disk periphery. Radial protuberances (157a and 157b) are formed on the inner surface of the cartridge so as to regulate the air flow between the cartridge and the disk surface. The disk substrate (10) accomodated in the cartridge is thicker in the periphery (12) than the recording region (14) to increase rigidity.

Abstract translation: 用于磁光盘记录/再现的光学头（67）和磁头（65）被放置在用于在磁头和磁盘之间形成窄气隙（68）的滑块（66a至66d）之间。 当空气由于盘（61）的旋转而沿着与轨迹相切的方向流动时，气隙中的压力增加，并且盘表面可以保持在预定位置，使得盘的垂直方向上的压力 61）变得均匀。 该结构对于基板厚度不大于0.85mm的薄盘是有效的。 对于薄盘有效的盘盒（101）包括与盘周边啮合的辊构件（111）。 径向突起（157a和157b）形成在盒的内表面上，以便调节盒与盘表面之间的气流。 容纳在盒中的盘基板（10）在周边（12）中比记录区域（14）更厚，以增加刚性。

公开(公告)号：WO1998009283A1

公开(公告)日：1998-03-05

申请号：PCT/JP1997002984

申请日：1997-08-27

Applicant: HITACHI MAXELL, LTD. ,  SHIMAZAKI, Katsusuke ,  IMAI, Susumu ,  OHTA, Norio ,  AWANO, Hiroyuki ,  YOSHIHIRO, Masafumi ,  WATANABE, Hitoshi ,  TAKAO, Hiroki

Inventor： HITACHI MAXELL, LTD.

IPC: G11B11/10

CPC classification number: G11B11/10595 ,  G11B11/10513 ,  G11B11/10515 ,  G11B11/10528 ,  G11B11/10584 ,  G11B11/10593 ,  G11B20/00086 ,  G11B20/1217 ,  G11B2020/1275 ,  G11B2020/1298 ,  G11B2220/2525

Abstract: A magnetic field H(x) or a reproducing beam L(x) of light whose intensity pattern is different is applied to the recording position of a magneto-optical recording medium, and different information corresponding to the patterns is read out of the same recording position. The function H(x) or L(x) is a password for obtaining the information. Only a person who knows the function can access the specific information recorded on the magneto-optical recording medium. The function H(x) or L(x) is a function such that the magnetic field intensity or the beam intensity is modulated with respect to the recording position (x) in such a manner that the information can be reproduced while magnetic domains are picked up from contiguous domains in the recording region at specific intervals. In addition to the security application, the information can be reproduced n times while a reproducing beam PL/PH, which is subjected to power modulation so as to apply a high power PH with a period n times the recording clock, is being projected to a specific magneto-optical recording medium such that magnetic domain expansion reproduction is possible, thereby improving the reproducing C/N significantly.

Abstract translation: 将强度图案不同的光的磁场H（x）或再现光束L（x）施加到磁光记录介质的记录位置，并且从同一记录中读出与图案对应的不同信息 位置。 函数H（x）或L（x）是用于获取信息的密码。 只有知道该功能的人才可以访问记录在磁光记录介质上的特定信息。 函数H（x）或L（x）是这样的功能，使得磁场强度或光束强度相对于记录位置（x）被调制，使得可以在拾取磁畴时再现信息 从特定间隔的记录区域中的连续域开始。 除了安全应用之外，可以再次n次地再现信息，而将经过功率调制以便施加具有n倍于记录时钟的周期的高功率PH的再现光束PL / PH投影到 特定的磁光记录介质，使得磁畴扩展再现成为可能，从而显着提高再现C / N。

公开(公告)号：WO1998002877A1

公开(公告)日：1998-01-22

申请号：PCT/JP1997002419

申请日：1997-07-11

Applicant: HITACHI MAXELL, LTD. ,  SANYO ELECTRIC CO., LTD. ,  OONUKI, Satoru ,  YOSHIHIRO, Masafumi ,  NAGAI, Nobuyuki ,  SHIMAZAKI, Katsusuke ,  AWANO, Hiroyuki ,  SHIRAI, Hiroshi ,  OHTA, Norio ,  SUMI, Satoshi ,  YAMAGUCHI, Atsushi

Inventor： HITACHI MAXELL, LTD. ,  SANYO ELECTRIC CO., LTD.

IPC: G11B11/10

CPC classification number: G11B11/10515 ,  G11B7/00745 ,  G11B11/10508 ,  G11B11/10521 ,  G11B11/10528 ,  G11B11/10578 ,  G11B11/10584 ,  G11B11/10593 ,  G11B11/10595 ,  G11B27/19 ,  G11B27/3027

Abstract: A magneto-optical recording medium (11) has a second auxiliary magnetic film (4), a first auxiliary magnetic film (5) and a magneto-optical recording film (6) in this order from the laser beam applied side. If the temperatures of the first and second auxiliary magnetic films (4 and 5) exceed their critical temperatures TCR1 and TCR2, the magnetization of the auxiliary magnetic films is changed from the surface magnetization to the vertical magnetization. The Curie points TC0, TC1 and TC2 of the magneto-optical recording film (6), the first auxiliary magnetic film (4) and the second auxiliary magnetic film (5) and the critical temperatures TCR1 and TCR2 satisfy the relations room temperature

Abstract translation: 从激光束施加侧开始，磁光记录介质（11）具有第二辅助磁膜（4），第一辅助磁膜（5）和磁光记录膜（6）。 如果第一和第二辅助磁膜（4和5）的温度超过它们的临界温度TCR1和TCR2，则辅助磁膜的磁化从表面磁化转变为垂直磁化。 磁光记录膜（6），第一辅助磁性膜（4）和第二辅助磁性膜（5）的居里点TC0，TC1和TC2以及临界温度TCR1和TCR2满足关系室温