专利快速检索-快速检索全球专利，免费商用专利数据库-IPRDB

1. 发明专利

DE2745266A1 未知
公开(公告)号：DE2745266A1
公开(公告)日：1978-04-13
申请号：DE2745266
申请日：1977-10-07
申请人： HITACHI LTD
发明人： OTA NORIO , ISHIDA FUMIHIKO
IPC分类号： H01F10/24 , H01F10/02 , G11C19/08 , G11C11/155
摘要： A garnet single crystal film wherein part of iron ions at tetrahedral positions and octahedral positions are replaced by an appointed amount of the other ions is by far superior to prior art garnet films in that its saturation magnetization (4 pi Ms) and its exchange stiffness coefficient (A) can be independently controlled to a desired value and a magnetic bubble domain having a small diameter can be easily formed.

2. 发明专利

JP2000339696A METHOD FOR RECORDING INFORMATION 失效
公开(公告)号：JP2000339696A
公开(公告)日：2000-12-08
申请号：JP2000144584
申请日：2000-05-12
申请人： HITACHI LTD
发明人： TERAO MOTOYASU , NISHIDA TETSUYA , YASUOKA HIROSHI , ANDO KEIKICHI , OTA NORIO
IPC分类号： G11B7/0045 , G11B7/0055 , G11B7/006 , G11B7/125
摘要： PROBLEM TO BE SOLVED: To surely cause reversible phase transition even when a recording film having a high phase transition rate is used, by forming the recording points with a single pulse or a plurality of pulses having the pulse width shorter than the period for the center of an energy beam spot passing from one end of a recording spot to the other end. SOLUTION: While an optical disk is rotated at a specified rotation rate, the laser light power is increased from a readout power level to a crystallization power level in an area for recording and then the power is varied. The power is increased for a short time to the level of amorphous transition in the region to be changed into an amorphous state according to an information signal. The time width when the laser power in increased to the amorphous level is specified to about 3/4 of the period when the center of the light spot passes from one end to the other end of the corresponding amorphous point (the region having lower crystallinity than in the surrounding area). The irradiated region of a disk is melted by irradiation of the laser light in the amorphous power level and then rapidly cooled to change into the amorphous state.

3. 发明专利

JPH07320330A OPTICAL DISC APPARATUS 失效
公开(公告)号：JPH07320330A
公开(公告)日：1995-12-08
申请号：JP12111195
申请日：1995-05-19
申请人： HITACHI LTD
发明人： YONEZAWA SEIJI , OTA NORIO , NIIHARA TOSHIO , KATAOKA KEIJI , TAKAHASHI MASAHIKO , MIYAMOTO JIICHI , SUKETA YASUSHI , TSUYOSHI TOSHIAKI
IPC分类号： G11B20/14 , G11B5/02 , G11B11/10 , G11B11/105
摘要： PURPOSE:To facilitate the high density overwriting by making a laser beam and a magnetic field synchronize with data clock signals to be modulated and controlling the laser beam and the magnetic field CONSTITUTION:A laser beam is applied to a magneto-optical disc 21 on which servo regions and data regions are alternately provided along approximately concentric tracks by a laser optical system 24 and a laser beam returned from the magneto-optical disc 21 is detected by a photodetector 29. A servo means controls the position to which the laser beam is applied in accordance with the output of the photodetector 29 which detects the laser beam which is modulated by tracking signal pits formed in the servo regions and returned. A clock circuit (PLL) 36 transmits clock signals 9 in accordance with the signals which are outputted by the photodetector 29 while the laser beam is applied to the servo region. A laser driving circuit 26 applies the laser beam to the data regions as continual pulses synchronized with the clock signals. A magnetic coil 27 applies a modulated magnetic field to the a magneto-optical disc 21 in accordance with data which are to be recorded synchronously with the clock signals.

4. 发明专利

JPH0447546A MAGNETO-OPTICAL RECORDING FILM 失效
公开(公告)号：JPH0447546A
公开(公告)日：1992-02-17
申请号：JP15523390
申请日：1990-06-15
申请人： HITACHI LTD , HITACHI MAXELL
发明人： KIRINO FUMIYOSHI , NAKAMURA JUNKO , TAKAHASHI MASAHIKO , OTA NORIO , MIYAMURA YOSHINORI
IPC分类号： G11B11/10 , G11B11/105
摘要： PURPOSE:To improve perpendicular magnetic anisotropy and magneto-optical effect and to improve the stability as a perpendicularly magnetized film and the reliability as a magneto-optical film by alternately laminating noble metal elements and rare earth/iron family element alloys. CONSTITUTION:The multilayered films alternately laminated with the alloy layers 2 formed by adding the rare earth elements having an effect of inducing the perpendicular magnetic anisotropy to the iron family elements, such as Fe and Co, and the noble metal element layers 3 consisting of one kind of the noble metal elements among Pt, Pd, Rh, and Au in Angstrom order are used. At least one kind of the elements among Tb, Dy, Ho, Gd, Nd, and Pr, are used as the rare earth elements. The high magneto-otpical effect and above all, the light of a large Kerr rotating angle and short wavelength are obtd. in this way. Ultra-high-density optial recording is thus executed. In addition, these films have the sufficiently large perpendicular magnetic anisotropy energy and is excellent in the stability of recording magnetic domains as well. The recording films having the high reliability are thereby obtd.

5. 发明专利

JPH03295046A MAGNETIC-OPTICAL RECORDING MEDIUM 失效
公开(公告)号：JPH03295046A
公开(公告)日：1991-12-26
申请号：JP9645690
申请日：1990-04-13
申请人： HITACHI LTD , HITACHI MAXELL
发明人： NIIHARA TOSHIO , MIYAMOTO JIICHI , SUZUKI YOSHIO , OTA NORIO
IPC分类号： G11B11/10 , G11B11/105
摘要： PURPOSE:To make the recording sensitivity equal in an outer circumference part and in an inner circumference part by providing a gradient in film thickness of a magnetic layer of high Curie temp. and a magnetic layer of low Curie temp. so that the outer circumference side has small thickness than the inner circumference side. CONSTITUTION:The magneto-optical recording medium 1 consists of a silicon nitride film 3 formed on a disk substrate 2, and further a Tb24Fe68Co8 amorphous magnetic layer 4 as a memory layer and Tb17Dy11Fe52Co20 amorphous magnetic layer 5 as an auxiliary layer are provided thereon. These magnetic layers 4, 5 are formed to have a gradient in film thickness that the outer circumference side is thinner than the inner circumference side. Then another silicon nitride film 3 is formed as the uppermost layer. Thereby, recording sensitivity is made equal for outer circumference part and for inner circumference part.

6. 发明专利

JPH03268247A MAGNETO-OPTICAL RECORDING MEDIUM AND ITS PRODUCTION 失效
公开(公告)号：JPH03268247A
公开(公告)日：1991-11-28
申请号：JP6416790
申请日：1990-03-16
申请人： HITACHI LTD
发明人： TAKAHASHI MASAHIKO , TAKAYAMA TAKANOBU , YOSHIDA KAZUYOSHI , OTA NORIO
IPC分类号： G11B11/10 , G11B11/105
摘要： PURPOSE:To enable stable high-density recording by alternately depositing noble metal films and transition metal-transition metal oxide mixture films to form a multi-layered magnetic film. CONSTITUTION:The magnetic film is formed by alternately depositing noble metal films and transition metal-transition metal oxide mixture films to form a multi-layered structure. The noble metal is at least one of Pt, Ag, and Pd, while the transition metal is at least one of Co, Mn, Ni, and Fe. For example, a SiN film 2 is formed on a glass substrate 1, on which a Pt/Co-O multilayered film 3 is formed. Thereby, the obtd. medium has large coercive force and small thermal conductivity and is suitable for stable high-density recording.

7. 发明专利

JPH03252933A INFORMATION RECORDING MEMBER 失效
公开(公告)号：JPH03252933A
公开(公告)日：1991-11-12
申请号：JP4937690
申请日：1990-03-02
申请人： HITACHI LTD , HITACHI MAXELL
发明人： TERAO MOTOYASU , ANDO KEIKICHI , MIYAUCHI YASUSHI , OTA NORIO
IPC分类号： G11B7/24 , G11B7/254 , G11B7/257
摘要： PURPOSE:To prevent scattering of laser light for reading due to thermal deformation or peeling by providing a protective layer comprising a mixture composition of specified materials adjacent to at least one side of a recording film. CONSTITUTION:A protective layer 2 is provided adjacent to a thin film 3 used as a recording film. This protective layer 2 consists of a mixture material of one material selected from ZnS, ZnSe, CdS, CdSe, and InS, or from materials having an almost same composition of these, and another material essentially comprising an oxide having a composition almost same as that of at least one oxide selected from Al2O3, Ta2O5, Cu2O, WO3, MoO3, CeO2, La2O3, and SiO. Thereby, deterioration, peeling or deformation due to irradiation of recording beam can be prevented and the obtd. medium shows little reduction of recording sensitivity.

8. 发明专利

JPH03235238A SYSTEM OF MAGNETO-OPTICAL RECORDING 失效
公开(公告)号：JPH03235238A
公开(公告)日：1991-10-21
申请号：JP2962190
申请日：1990-02-13
申请人： HITACHI LTD , HITACHI MAXELL
发明人： OTA NORIO , KIRINO FUMIYOSHI
IPC分类号： G11B11/10 , G11B5/02 , G11B11/105
摘要： PURPOSE:To make improvement in data transfer rate by using an optical head corresponding to plural magnetic heads. CONSTITUTION:A magneto-optical disk 1 is subjected to recording, reproducing or erasing by using the optical head of multiple light beams corresponding to the plural small-sized magnetic heads 9, such as permanent magnets. The data transfer speed improves when the parallel magneto-optical recording, etc., are executed by combining the heads of every other track in order to prevent interference and crosstalks in this case. The effect thereof is additionally enhanced by the combination with the improvement in recording density, etc., by the utilization of bit edge recording and short wavelength light, etc.

9. 发明专利

JPH03235237A STRUCTURE OF MAGNETO-OPTICAL RECORDING MEDIUM 失效
公开(公告)号：JPH03235237A
公开(公告)日：1991-10-21
申请号：JP2962090
申请日：1990-02-13
申请人： HITACHI LTD , HITACHI MAXELL
发明人： KIRINO FUMIYOSHI , MIYAMURA YOSHINORI , NAKAMURA JUNKO , OTA NORIO
IPC分类号： G11B11/10 , G11B11/105
摘要： PURPOSE:To enable super-high density recording and overwriting by forming a recording film of a multilayer structure comprising various kinds of perpendicular magnetization films having different magnetic characteristics magnetically coupled to one another. CONSTITUTION:On a transparent substrate 1, there are formed a magneto-optical enhancing film 2, recording film comprising first and second magnetic films 3, 4, respectively, having different magnetic characteristics but coupled to each other magnetically, then again the film 2, reflecting film 5 opposite to the light incident side, etc., to constitute the magneto-optical recording medium. Recording can be performed by orienting the magnetization direction in the film 4 while not changing the direction of magnetization in the film 3 with low level laser iradiation. Similarly, with high-level laser light, recording can be performed in the film 3 for overwriting. By repeating deposition of the films 3, 4 for a multilayer structure, super-high density recording can be realized.

10. 发明专利

JPH03185629A METHOD FOR RECORDING INFORMATION 失效
公开(公告)号：JPH03185629A
公开(公告)日：1991-08-13
申请号：JP32146689
申请日：1989-12-13
申请人： HITACHI LTD
发明人： MIYAUCHI YASUSHI , TERAO MOTOYASU , ANDO KEIKICHI , NIIHARA TOSHIO , KUREBAYASHI MASAAKI , MIYAMOTO JIICHI , OTA NORIO
IPC分类号： G11B11/10 , G11B7/00 , G11B7/0045 , G11B7/125 , G11B7/24 , G11B11/105
摘要： PURPOSE:To obtain the reproduction signal corresponding faithfully to a recording signal by not changing the irradiation power of an energy beam to an intermediate level from a high level but interposing the period of the level lower than the intermediate level between the same. CONSTITUTION:The waveforms including the upward pulse part (1) heading from the intermediate level M toward the high level H and the downward pulse part (2) heading further from the intermediate level M to the low level L are used as the pulse waveforms to execute the power control of the irradiation beam. Namely, the downward pulse added to the pulse waveform of the beam power acts to accelerate the heating and cooling of the recording film of the irradiation region. The conduction and accumulation of the high heat to and in the outside of this region are effectively prohibited and the undesirable expansion of the recording point is prevented. The reproduction signal faithfully corresponding to the recording signal is obtd. even in the case of the storage pulse of the long duration time of the high level or when the many recording pulses of the narrow pulse intervals continue.

你已经成功收藏专利！

检索式保存成功!

IPRDB

热门服务

关于我们

友情链接

联系方式