WO2004061837A1 - 磁界発生機および光磁気情報記憶装置 - Google Patents
磁界発生機および光磁気情報記憶装置 Download PDFInfo
- Publication number
- WO2004061837A1 WO2004061837A1 PCT/JP2002/013704 JP0213704W WO2004061837A1 WO 2004061837 A1 WO2004061837 A1 WO 2004061837A1 JP 0213704 W JP0213704 W JP 0213704W WO 2004061837 A1 WO2004061837 A1 WO 2004061837A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- magnetic
- coil
- magnetic field
- field generator
- rod
- Prior art date
Links
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B13/00—Recording simultaneously or selectively by methods covered by different main groups among G11B3/00, G11B5/00, G11B7/00 and G11B9/00; Record carriers therefor not otherwise provided for; Reproducing therefrom not otherwise provided for
- G11B13/04—Recording simultaneously or selectively by methods covered by different main groups among G11B3/00, G11B5/00, G11B7/00 and G11B9/00; Record carriers therefor not otherwise provided for; Reproducing therefrom not otherwise provided for magnetically or by magnetisation and optically or by radiation, for changing or sensing optical properties
- G11B13/045—Recording simultaneously or selectively by methods covered by different main groups among G11B3/00, G11B5/00, G11B7/00 and G11B9/00; Record carriers therefor not otherwise provided for; Reproducing therefrom not otherwise provided for magnetically or by magnetisation and optically or by radiation, for changing or sensing optical properties combined recording by magnetic and optic means
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B11/00—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor
- G11B11/10—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field
- G11B11/105—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field using a beam of light or a magnetic field for recording by change of magnetisation and a beam of light for reproducing, i.e. magneto-optical, e.g. light-induced thermomagnetic recording, spin magnetisation recording, Kerr or Faraday effect reproducing
- G11B11/10532—Heads
- G11B11/10534—Heads for recording by magnetising, demagnetising or transfer of magnetisation, by radiation, e.g. for thermomagnetic recording
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B11/00—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor
- G11B11/10—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field
- G11B11/105—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field using a beam of light or a magnetic field for recording by change of magnetisation and a beam of light for reproducing, i.e. magneto-optical, e.g. light-induced thermomagnetic recording, spin magnetisation recording, Kerr or Faraday effect reproducing
- G11B11/1055—Disposition or mounting of transducers relative to record carriers
- G11B11/10552—Arrangements of transducers relative to each other, e.g. coupled heads, optical and magnetic head on the same base
- G11B11/10554—Arrangements of transducers relative to each other, e.g. coupled heads, optical and magnetic head on the same base the transducers being disposed on the same side of the carrier
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F7/00—Magnets
- H01F7/06—Electromagnets; Actuators including electromagnets
- H01F7/20—Electromagnets; Actuators including electromagnets without armatures
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F3/00—Cores, Yokes, or armatures
- H01F3/10—Composite arrangements of magnetic circuits
Definitions
- the present invention relates to a magnetic field generator that generates a magnetic field, and a magneto-optical information storage device that performs information access to an information recording medium using light and a magnetic field.
- information recording media such as CD, CD-ROM, CD-R, DVD, PD, MO, and MD have been widely used as large-capacity recording media for storing audio signals and image signals.
- magneto-optical information recording media where information is accessed using light and a magnetic field, are attracting attention as high-density recording media on which information can be rewritten, and research and development are being actively conducted to further increase the recording density.
- research and development of a magneto-optical information storage device for performing information reproduction and information storage on such a magneto-optical information recording medium at a higher speed are being actively carried out.
- an optical modulation method of recording information on a recording medium by optical modulation according to information is adopted.
- a magnetic field modulation method of recording information by magnetic field modulation according to the information there is a tendency to adopt a magnetic field modulation method of recording information by magnetic field modulation according to the information.
- a modulated magnetic field is generated by using a thin-film coil manufactured by a semiconductor process.
- the temperature of a recording film of a recording medium is brought close to one point of a Curie by condensing a laser beam for recording, and in that state, the temperature is generated by a coil.
- a magnetic field By applying a magnetic field to the recording film, information is recorded with the magnetization direction of the recording film oriented in a direction corresponding to the information.
- an optical system for condensing light on a recording medium and a magnetic system for generating a magnetic field are required.
- Front illuminator that arranges the coil on the same side as viewed from the recording medium It is desirable to have a configuration of a solution type. In this configuration, an annular magnetic coil is generally arranged between the optical system and the recording medium.
- FIG. 1 shows an example in which a disk-shaped magnetic layer having a hole in the center is provided.
- a magnetic coil When a magnetic coil is driven at a high frequency (for example, 50 MHz) when such a magnetic layer is provided, an eddy current is generated in the magnetic layer due to a change in magnetization of the magnetic layer.
- the eddy current causes a loss and raises the temperature of the magnetic body.
- This rise in temperature causes a rise in the temperature of the magnetic coil, which may cause a phenomenon called “migration” in which the magnetic coil becomes thin and thin and, in extreme cases, breaks.
- the rise in temperature of the magnetic coil increases the resistance of the magnetic coil, causing damage to the magnetic coil due to heat generation.
- the present invention provides a magnetic field generator that can be produced by a simple manufacturing technique such as a plating method and can suppress the generation of eddy current, and an optical device that can record and reproduce data at high speed. It is an object to provide a magnetic information storage device.
- the magnetic field generator of the present invention that achieves the above object,
- the coil is insulated from the coil and is made of a magnetic material.
- the ratio between the maximum width and the minimum width is less than 2 times.
- the magnetic field generated by the coil is enhanced by the magnetic rod, and the eddy current loss is suppressed to be small by the rod-like structure of the magnetic rod. Further, such a rod-shaped structure of a magnetic rod can be manufactured by a simple manufacturing technique such as a plating method, and the manufacturing cost is suppressed.
- the magnetic rod is made of a magnetic material having a saturation magnetic flux density of 1.5 (T) or more, and has a thickness of 3 m or less and a width of 6 m or less. is there.
- the magnetic rod having such dimensions can effectively reduce eddy current loss, and can obtain a sufficient magnetic field generating ability by having a saturation magnetic flux density of 1.5 (T) or more.
- the magnetic rod has a length that is at least twice the width from the edge of the inner hole to the outer edge of the coil.
- the magnetic rod having such a length can efficiently enhance the magnetic field generated by the coil.
- the plurality of magnetic rods have a total volume of the plurality of magnetic rods smaller than a total volume of a space between the plurality of magnetic rods. is there.
- the magnetic rod has a wide portion at a position overlapping the coil.
- the magnetic rod can efficiently enhance the magnetic field.
- the magnetic rod is made of a magnetic material having a magnetic permeability of 500 or more.
- a typical magnetic bar in the magnetic field generator according to the present invention is made of C on Ni Fe.
- the magnetic field generator according to the present invention may further include a heat radiator outside the coil, which is provided at a position in which at least 1 Z6 of the outer diameter of the coil is opened from the outer edge of the coil and which comes into thermal contact with the magnetic rod and removes heat from the magnetic rod. It is preferable to provide a heat radiator outside the coil, which is provided at a position in which at least 1 Z6 of the outer diameter of the coil is opened from the outer edge of the coil and which comes into thermal contact with the magnetic rod and removes heat from the magnetic rod. It is preferable to provide
- the thermal performance of the magnetic field generator is further improved.
- a typical heat radiator outside the coil in the magnetic field generator according to the present invention is made of copper. Further, the magnetic field generator according to the present invention is provided between the plurality of magnetic rods, and is insulated from the magnetic rods. It is also preferable to provide an inter-rod heat radiator that contacts the magnetic rods and removes the heat of the magnetic rods.
- Such a rod-to-rod heat sink also removes heat from the magnetic rod, thus improving the thermal performance of the magnetic field generator.
- a typical radiator between rods in the magnetic field generator of the present invention is made of copper. Furthermore, the magnetic field generator of the present invention is provided at a position in which at least 1 Z6 of the outer diameter of the coil is opened from the outer edge of the coil, and is connected to the radiator between the rods. It is also preferable to provide an external coil radiator for removing heat from the rod.
- the heat of the magnetic rod is deprived by the radiator between the rods, is efficiently transmitted to the radiator outside the coil, and is radiated to the outside by the radiator outside the coil. This further improves the thermal performance of the magnetic field generator.
- An annular coil surrounding the inner hole which is provided on the information recording medium side of the condenser lens and generates a magnetic field at a position on the information recording medium where the condenser lens condenses light; Between the coil and the condensing lens, radially arranged around the inner hole of the coil, insulated from the coil, made of magnetic material, the ratio of the maximum width to the minimum width is twice or less And a plurality of magnetic rods.
- FIG. 1 is a diagram showing one embodiment of the magneto-optical information storage device of the present invention, in which one embodiment of the magnetic field generator of the present invention is incorporated.
- FIG. 2 is a perspective view showing the configuration of the head.
- FIG. 3 is an enlarged view showing the vicinity of the condenser lens 300 of the moving assembly.
- FIG. 4 is a 1/4 configuration diagram of the magnetism generator.
- FIG. 5 is a partially enlarged view of the magnetism generating section.
- FIG. 6 is a graph showing the magnetic field generation ability in the comparative example.
- FIG. 7 is a graph showing the magnetic field generation ability in the present embodiment.
- FIG. 8 is a graph showing the effect of reducing eddy current loss.
- FIG. 9 is an explanatory diagram of a method for producing a magnetic core provided in the present embodiment.
- FIG. 10 is a 1Z4 configuration diagram of a magnetic generation unit according to another embodiment.
- FIG. 1 is a diagram showing one embodiment of the magneto-optical information storage device of the present invention, in which one embodiment of the magnetic field generator of the present invention is incorporated.
- the magneto-optical information storage device 100 exemplified here includes the magneto-optical information storage device 100 An aluminum alloy drive base 110 serving as a base is provided, and the drive base 110 is attached to the frame 130. A top cover 140 and a bottom cover (not shown) are screwed to the drive base 110, respectively.
- the frame 130 has a front panel 160 mounted thereon.
- the front panel 160 has a MO disk having a built-in magneto-optical (MO) disk corresponding to an example of the information recording medium according to the present invention.
- An entry port 161 for inserting the cartridge into the magneto-optical information storage device 100 is provided.
- a connector for electrically connecting the magneto-optical information storage device 100 to a device such as a computer is provided at the rear end of the magneto-optical information storage device 100 that is opposite to the front end on which the front panel 160 is mounted. 170 is mounted.
- a spindle motor that holds and rotates the MO disk, and the recording and reproduction of information by irradiating light and applying a magnetic field to the M ⁇ disk. Is mounted.
- FIG. 2 is a perspective view showing the configuration of the head.
- the head is composed of a moving assembly 190 that can move in the radial direction of the M ⁇ disk 240 and a fixing assembly 200 that is fixed to the drive base 110 shown in FIG. ,
- the fixed assembly 200 includes a laser diode 202 that is an example of a light source according to the present invention, which generates laser light used for reading and writing information, and a light reflected by the M ⁇ disk 240.
- a photodetector 203 for detecting a signal corresponding to information stored in the MO disk 240 and a track spirally provided on the MO disk as a place for storing information.
- a photodetector 204 for detecting a shift of the focused spot and a photodetector 205 for detecting a shift of the focus of the focused spot are attached.
- the moving assembly 190 is driven by a pair of magnetic circuits 250 and moves in the radial direction of the M ⁇ disk 240 along a pair of guide rails 260.
- a fine adjustment of the position of the lens 300 to adjust the focus of the condensed spot and an actuary for positioning the condensed spot on a track are provided.
- the fine adjustment of the position of the condenser lens 300 by the actuator is performed based on the deviation detected by the photodetectors 204 and 205 described above.
- the moving assembly 190 is provided with a cylinder opening 192 having a rectangular cross section, and the laser light emitted by the laser diode 12 of the fixed assembly 200 transmits the moving assembly 192 from the cylinder opening 192. Enter within 190. Also, the light reflected by the MO disk 240 returns to the fixing assembly 200 from the cylinder opening 192. Further, in the moving assembly 190, a rising mirror for making the laser beam entering from the cylinder opening 192 incident on the condenser lens 300 is built in behind the cylinder opening 192.
- FIG. 3 is an enlarged view showing the vicinity of the condenser lens 300 of the moving assembly.
- the MO disk 240 is composed of a substrate 241 and a recording layer 242, and the condenser lens described above is composed of a hemispherical lens 301 and an aspherical lens 302.
- the laser beam L guided from the above-described fixed assembly passes through the hemispherical lens 301 and the aspherical lens 302 and is condensed on the recording layer 242 on the MO disk 240 to form a light spot. .
- a magnetic generator 310 corresponding to one embodiment of the magnetic field generator of the present invention is provided on the MO disk 240 side of the aspherical lens 302.
- a magnetic field perpendicular to the recording layer 242 is generated at the position where the converging spot is formed.
- the temperature reaches the Curie point due to the irradiation of the laser beam L, and the magnetic domain of the recording layer 242 is generated by the magnetic field generated by the magnetic generation unit 310. Is determined in a direction corresponding to the recorded information. As a result, information is recorded on the M ⁇ disk 240.
- the magnetism generator 310 has a coil 311, a magnetic core 312, and a radiator 313.
- FIG. 4 is a 1Z4 configuration diagram of the magnetic generation unit
- FIG. 5 is a partially enlarged view of the magnetic generation unit.
- the coil 311 corresponds to an example of the coil according to the present invention, and is a so-called thin-film coil having an annular shape surrounding an inner hole through which the laser light L passes.
- This coil 3 The diameter of the inner hole of 11 is 200 m and the outer diameter is 600 m. Therefore, the width from the edge to the outer edge of the inner hole is 200 m.
- a current that changes in a direction corresponding to the recorded information is applied to the coil 311.
- the maximum frequency of the current is 20 MHz or more in consideration of the recording data transfer speed. That is, the current flowing through the coil 311 and the magnetic field generated by the coil 311 rapidly reverse within a short time of 50 ns or less.
- the magnetic core 312 corresponds to an example of the magnetic bar according to the present invention, and is made of CoNiFe, and has a rod-like shape with a thickness of 3 m and a width of 6 m. These magnetic cores 3 1 2 are radially arranged around the inner hole of the coil 3 11, and the length of each core 3 12 is the width from the edge of the inner hole of the coil 3 1 1 to the outer edge. It is 400 m, which is twice as large. The total volume of the magnetic cores 3 12 is smaller than the total volume of the space between the magnetic cores 3 12.
- the magnetic field lines of the magnetic field generated by the coil 3 1 1 are led to the radially arranged magnetic core 3 1 2, and are the coils 3 1 1 inside?
- the intensity of the magnetic field at the spot position on the M ⁇ disk increases.
- Co NiFe constituting the magnetic core 312 is a magnetic material having a saturation magnetic flux density exceeding 1.5 T, the magnetic core 312 can sufficiently increase the magnetic field strength.
- the magnetic core 312 generates a demagnetizing field with respect to the magnetic field generated by the coil 311. If the demagnetizing field is strong, the internal magnetic field of the magnetic core 312 is attenuated and the magnetization of the magnetic core 312 is reduced. The effect of increasing the magnetic field strength by the magnetic core 3 12 is also suppressed.
- the strength of this demagnetizing field is determined by the structure of the magnetic core 3 12, and in the present embodiment, the magnetic core 3 12 has the rod-like shape as described above, and the total volume is suppressed. Have a small demagnetizing field and a large magnetization.
- Each magnetic core 3 12 is provided with a wide portion 3 12 a around the coil 3 11, thereby further improving the effect of increasing the magnetic field strength.
- the magnetic core 3 12 When the magnetic field generated by the coil 311 rapidly reverses as described above, eddy current loss occurs in each of the 312 cores and heat is generated. As a result, the area of the cross section perpendicular to the lines of magnetic force is small, and eddy current loss and heat generation are suppressed. As a result, even when the coil 311 is driven at a high frequency, the power consumption of the coil 311 can be suppressed to avoid the temperature rise of the coil 311. Can be. As a result of avoiding the temperature rise of the coil 311, the coil 311 can generate a stronger magnetic field. In order to reduce eddy current loss while maintaining large magnetization, it is effective for the magnetic core 3 12 to have a rod-like shape in which the ratio of the maximum width to the minimum width is 2 times or less. .
- the heat radiator 3 13 corresponds to an example of the heat radiator outside the coil according to the present invention.
- the heat radiator 3 13 A distance of 100 m corresponding to 16 of the outer diameter is provided at a position spaced from the outer edge of the coil 311.
- the heat radiator 3 13 is in thermal contact with each of the magnetic cores 3 12 and removes heat from each of the magnetic cores 3 12.
- the magnetic field generating ability in the comparative example having the annular magnetic layer in which the above-described magnetic cores 312 are connected to each other will be compared with the magnetic field generating ability in the present embodiment.
- FIG. 6 is a graph showing the magnetic field generating ability in the comparative example
- FIG. 7 is a graph showing the magnetic field generating ability in the present embodiment.
- the horizontal axis of these graphs represents the position on the center axis of the coil (that is, the optical axis of the condenser lens) with respect to the center of the coil, and the vertical axis represents the magnetic field strength.
- solid lines LI and L4 represent the magnetic field generating ability when the magnetic core and the magnetic layer are made of a magnetic material having a magnetic permeability (') of 100
- the broken lines L2 and L4 L 5 represents the magnetic field generating ability when the magnetic core and the magnetic layer are made of a magnetic material having a magnetic permeability () of 500
- dashed lines L 3 and L 6 indicate the magnetic permeability () Represents the magnetic field generation ability when the magnetic core and the magnetic layer are made of a magnetic material of 200.
- the magnetic permeability differs in the range from 200 to 1000. However, there is almost no difference in the magnetic field strength. This is because the demagnetizing field in the toroidal magnetic layer is large, so that even if the magnetic permeability is large, the demagnetizing field increases accordingly. Means that.
- the magnetic permeability differs in the range from 200 to 100, a difference occurs in the magnetic field strength.
- An example The same magnetic field strength can be obtained. This means that a rod-shaped magnetic core has a small demagnetizing field, so that if the magnetic permeability is large, the magnetic field strength is also large. From the original purpose of the magnetic field generator, it is desirable that the magnetic field generating capability of the magnetic field generator is approximately the same as the magnetic field generating capability of the comparative example, so that the magnetic material constituting the magnetic core has a magnetic permeability of
- the magnetic material exceed 500. It is also desirable to reduce the eddy current loss by using a rod-like shape while maintaining the same magnetic field generation capability as the comparative example, and to use a thin rod-like shape with a thickness of 3 m and a width of 6 m. In order to obtain sufficient magnetic field generation capability, it is desirable to have a saturation magnetic flux density of 1.5 T or more.
- a magnetic material having such a magnetic permeability and a saturation magnetic flux density for example, C on Ni Fe exists. Note that NiFe is also suitable as a magnetic material, although it is slightly inferior to the above-described magnetic permeability and saturation magnetic flux density.
- FIG. 8 is a graph showing the effect of reducing eddy current loss.
- the horizontal axis of FIG. 8 represents the driving frequency of the coil, and the vertical axis represents the resistance generated by driving the coil.
- the solid line L7 in this graph represents the resistance generated in the comparative example described above
- the broken line L8 in the graph represents the resistance generated in the present embodiment
- the one-dot chain line L9 in the graph represents the magnetic core and the like. It shows the resistance generated only by the coil having no magnetic layer.
- the resistance increases from around 100 MHz due to the skin effect.
- the resistance rapidly increases from around several MHz, and a large eddy current loss occurs.
- the degree of increase is moderate, and the effect of reducing the eddy current loss is obtained.
- each component other than the magnetic core in the magnetic field generating unit can be formed by a semiconductor process using a plating process or an exposure process, so that the description of the forming method is omitted.
- FIG. 9 is an explanatory diagram of a method for producing a magnetic core provided in the present embodiment.
- a glass substrate 401 having a desired refractive index is selected (step S1), and a plating base (base) 402 for forming a magnetic material layer is formed on the glass substrate 401 by vacuum.
- a film is formed by a vapor deposition method or a sputtering method (Step S2).
- the thickness of the base 402 may be several nm to several tens nm.
- a resist 403 is applied on the underlayer 402, and exposure and development are performed using a radially patterned mask. As a result, a resist 403 having the same shape as the mask pattern is left on the plating base 402 (step S3).
- a magnetic material layer 404 is formed on the base 402 other than the portion covered with the resist 403 by a plating process (step S4). After that, the resist 404 is removed by using a stripping solution (Step S5).
- step S6 the entire surface is uniformly cut off by the thickness of the base 402 by milling or the like, and the protrusions are separated from each other, thereby forming the above-described rod-shaped magnetic core 312 (step S6).
- a film 405 of an insulating material such as alumina is formed so as to cover the rod-shaped magnetic core 312 so as to insulate the rod-shaped magnetic core 312 from other layers to be laminated thereafter (Step S7). ), And further grow an alumina layer 406 (step S8). Finally, a process of flattening the uneven shape of the alumina layer 406 by CMP (Chemical Mecanica1Polish) is performed (step S9).
- CMP Chemical Mecanica1Polish
- a bar-shaped magnetic core or the like can be created by applying a semiconductor process.
- a low-cost plating process can be used, so that the production cost of the magnetic field generating part itself can be suppressed.
- This alternative embodiment is substantially the same as the above-described embodiment except that a heat radiator is embedded between the rod-shaped magnetic cores. Therefore, the following description will focus on only the differences. Do.
- FIG. 10 is a 1Z4 configuration diagram of a magnetic generation unit according to another embodiment
- FIG. 11 is a cross-sectional view of the magnetic generation unit.
- Cu is used between the rod-shaped cores 312 described above.
- Radiator 3 14 is embedded.
- the radiator 314 corresponds to an example of the radiator between rods according to the present invention, and is formed by growing a Cu layer instead of an alumina layer in step S8 of the production procedure shown in FIG. Is done. Therefore, the above-mentioned alumina film exists between the magnetic core 312 and the heat radiator 314 and is insulated.
- the heat radiator 3 14 between the magnetic cores 3 1 and 2 is joined to the heat radiator 3 13 disposed around the coil 3 1 1 via a bonding layer 3 15, and the magnetic core 3 1 2
- the heat generated can be taken away and the heat can be efficiently released to the radiator 3 13 around the coil 3 11.
- a rod-shaped magnetic core having a substantially constant width is exemplified as an example of the magnetic rod according to the present invention.
- the magnetic rod according to the present invention has a maximum width and a minimum width. As long as the ratio does not exceed 2 times, for example, the shape may be gradually increased toward one end.
Landscapes
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Recording Or Reproducing By Magnetic Means (AREA)
Abstract
Description
Claims
Priority Applications (7)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE60227570T DE60227570D1 (de) | 2002-12-26 | 2002-12-26 | Magnetischer feldgenerator und magneto-optisches informationsspeichergerät |
CNB028293517A CN100545926C (zh) | 2002-12-26 | 2002-12-26 | 磁场发生器和光磁信息存储装置 |
AU2002361108A AU2002361108A1 (en) | 2002-12-26 | 2002-12-26 | Magnetic field generator and magneto-optical information storage device |
JP2004564433A JP4047861B2 (ja) | 2002-12-26 | 2002-12-26 | 磁界発生機および光磁気情報記憶装置 |
EP02792024A EP1528550B1 (en) | 2002-12-26 | 2002-12-26 | Magnetic field generator and magneto-optical information storage device |
PCT/JP2002/013704 WO2004061837A1 (ja) | 2002-12-26 | 2002-12-26 | 磁界発生機および光磁気情報記憶装置 |
US11/029,427 US7466634B2 (en) | 2002-12-26 | 2005-01-06 | Magnetic field generator and photomagnetic information storage apparatus |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
PCT/JP2002/013704 WO2004061837A1 (ja) | 2002-12-26 | 2002-12-26 | 磁界発生機および光磁気情報記憶装置 |
Related Child Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US11/029,427 Continuation US7466634B2 (en) | 2002-12-26 | 2005-01-06 | Magnetic field generator and photomagnetic information storage apparatus |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2004061837A1 true WO2004061837A1 (ja) | 2004-07-22 |
Family
ID=32697319
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2002/013704 WO2004061837A1 (ja) | 2002-12-26 | 2002-12-26 | 磁界発生機および光磁気情報記憶装置 |
Country Status (7)
Country | Link |
---|---|
US (1) | US7466634B2 (ja) |
EP (1) | EP1528550B1 (ja) |
JP (1) | JP4047861B2 (ja) |
CN (1) | CN100545926C (ja) |
AU (1) | AU2002361108A1 (ja) |
DE (1) | DE60227570D1 (ja) |
WO (1) | WO2004061837A1 (ja) |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH05225501A (ja) * | 1992-02-12 | 1993-09-03 | Ricoh Co Ltd | 磁界変調型光磁気記録装置用磁気ヘッド |
JPH076443A (ja) * | 1992-10-31 | 1995-01-10 | Samsung Electron Co Ltd | 光磁気ディスクドライブ |
JP2000036141A (ja) * | 1998-05-11 | 2000-02-02 | Quantum Corp | フライング光ヘッドアセンブリおよび光ディスクドライブデ―タ記憶システム |
JP2000090403A (ja) * | 1998-09-10 | 2000-03-31 | Canon Inc | 光磁気記録用磁気ヘッドおよび光磁気記録装置 |
JP2002230860A (ja) * | 2000-10-10 | 2002-08-16 | Hitachi Maxell Ltd | 光磁気ヘッド及びそれを用いた光磁気記録装置 |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0935937A (ja) | 1995-05-17 | 1997-02-07 | Alps Electric Co Ltd | インダクタンス素子 |
US5903525A (en) * | 1997-04-18 | 1999-05-11 | Read-Rite Corporation | Coil for use with magneto-optical head |
JPH10320863A (ja) | 1997-05-19 | 1998-12-04 | Sony Corp | 記録再生装置 |
JP3507360B2 (ja) * | 1998-05-07 | 2004-03-15 | キヤノン株式会社 | 磁気ヘッド用平面コイル部品、光磁気記録用磁気ヘッドおよび光磁気記録装置 |
JP2003178498A (ja) * | 2001-12-11 | 2003-06-27 | Fujitsu Ltd | 磁気ヘッドおよびデータ記録再生装置 |
JP2005141810A (ja) * | 2003-11-05 | 2005-06-02 | Fujitsu Ltd | 光磁気ヘッドおよび光磁気ディスク装置 |
-
2002
- 2002-12-26 JP JP2004564433A patent/JP4047861B2/ja not_active Expired - Lifetime
- 2002-12-26 EP EP02792024A patent/EP1528550B1/en not_active Expired - Lifetime
- 2002-12-26 CN CNB028293517A patent/CN100545926C/zh not_active Expired - Lifetime
- 2002-12-26 AU AU2002361108A patent/AU2002361108A1/en not_active Abandoned
- 2002-12-26 DE DE60227570T patent/DE60227570D1/de not_active Expired - Fee Related
- 2002-12-26 WO PCT/JP2002/013704 patent/WO2004061837A1/ja active IP Right Grant
-
2005
- 2005-01-06 US US11/029,427 patent/US7466634B2/en active Active
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH05225501A (ja) * | 1992-02-12 | 1993-09-03 | Ricoh Co Ltd | 磁界変調型光磁気記録装置用磁気ヘッド |
JPH076443A (ja) * | 1992-10-31 | 1995-01-10 | Samsung Electron Co Ltd | 光磁気ディスクドライブ |
JP2000036141A (ja) * | 1998-05-11 | 2000-02-02 | Quantum Corp | フライング光ヘッドアセンブリおよび光ディスクドライブデ―タ記憶システム |
JP2000090403A (ja) * | 1998-09-10 | 2000-03-31 | Canon Inc | 光磁気記録用磁気ヘッドおよび光磁気記録装置 |
JP2002230860A (ja) * | 2000-10-10 | 2002-08-16 | Hitachi Maxell Ltd | 光磁気ヘッド及びそれを用いた光磁気記録装置 |
Non-Patent Citations (1)
Title |
---|
See also references of EP1528550A4 * |
Also Published As
Publication number | Publication date |
---|---|
CN1639786A (zh) | 2005-07-13 |
JPWO2004061837A1 (ja) | 2006-05-18 |
US7466634B2 (en) | 2008-12-16 |
EP1528550B1 (en) | 2008-07-09 |
CN100545926C (zh) | 2009-09-30 |
AU2002361108A1 (en) | 2004-07-29 |
EP1528550A1 (en) | 2005-05-04 |
US20050105403A1 (en) | 2005-05-19 |
DE60227570D1 (de) | 2008-08-21 |
EP1528550A4 (en) | 2005-11-16 |
JP4047861B2 (ja) | 2008-02-13 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US7133230B2 (en) | Recording head and information recording apparatus | |
JP2001325756A (ja) | 光磁気素子、光磁気ヘッドおよび磁気ディスク装置 | |
EP0742557B1 (en) | Thin film magnetic head for use with magneto-optic disc drive | |
JP3902952B2 (ja) | 光誘導型薄膜磁気ヘッド | |
JP2001023260A (ja) | 磁界変調用磁気ヘッド、磁気光学素子、光学ピックアップ装置および光ディスク装置 | |
WO2004061837A1 (ja) | 磁界発生機および光磁気情報記憶装置 | |
JP4402054B2 (ja) | 情報の記録・再生装置、情報の記録媒体及び記録装置 | |
KR100704819B1 (ko) | 자계 발생기 및 광자기 정보 기억 장치 | |
JP3104201B2 (ja) | 光学記録媒体 | |
JPH11232718A (ja) | 光磁気ヘッド及び光磁気記録装置 | |
JP2003178498A (ja) | 磁気ヘッドおよびデータ記録再生装置 | |
JP2007115375A (ja) | 磁気記録再生装置 | |
JP2000285542A (ja) | 光磁気ヘッド | |
US20020110082A1 (en) | Magnetic head with a permanent-magnet layer structure | |
JP2004087068A (ja) | 複合光学ヘッドおよびこれを用いた光ディスク装置 | |
JP3104202B2 (ja) | 光学記録媒体 | |
JP4949313B2 (ja) | 情報記録媒体、情報記録装置、情報記録方法、および該情報記録媒体の製造方法 | |
JP3312116B2 (ja) | 光磁気記録装置 | |
JP3022375B2 (ja) | 光磁気記録媒体記録再生装置 | |
JP3617806B2 (ja) | 熱アシスト磁気ヘッド及びそれを用いた熱アシスト磁気記録装置 | |
JP2000215539A (ja) | 光学素子、記録及び/又は再生装置、並びに光学素子の製造方法 | |
JP2000285544A (ja) | 光磁気記録再生装置 | |
JP2005063670A (ja) | 光学記録媒体及び光ディスクシステム | |
JP2007018707A (ja) | 光学記録媒体及び光ディスクシステム | |
JP2002056502A (ja) | 記録再生ヘッド及び磁気記録装置 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AK | Designated states |
Kind code of ref document: A1 Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NO NZ OM PH PL PT RO RU SD SE SG SK SL TJ TM TN TR TT TZ UA UG US UZ VN YU ZA ZM ZW |
|
AL | Designated countries for regional patents |
Kind code of ref document: A1 Designated state(s): GH GM KE LS MW MZ SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR IE IT LU MC NL PT SE SI SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
WWE | Wipo information: entry into national phase |
Ref document number: 2004564433 Country of ref document: JP |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2002792024 Country of ref document: EP |
|
WWE | Wipo information: entry into national phase |
Ref document number: 1020047020895 Country of ref document: KR |
|
WWE | Wipo information: entry into national phase |
Ref document number: 11029427 Country of ref document: US |
|
WWE | Wipo information: entry into national phase |
Ref document number: 20028293517 Country of ref document: CN |
|
WWP | Wipo information: published in national office |
Ref document number: 2002792024 Country of ref document: EP |
|
WWP | Wipo information: published in national office |
Ref document number: 1020047020895 Country of ref document: KR |
|
WWG | Wipo information: grant in national office |
Ref document number: 2002792024 Country of ref document: EP |