WO2004081930A1 - 光磁気記録媒体及び光磁気記録装置 - Google Patents
光磁気記録媒体及び光磁気記録装置 Download PDFInfo
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- WO2004081930A1 WO2004081930A1 PCT/JP2003/002888 JP0302888W WO2004081930A1 WO 2004081930 A1 WO2004081930 A1 WO 2004081930A1 JP 0302888 W JP0302888 W JP 0302888W WO 2004081930 A1 WO2004081930 A1 WO 2004081930A1
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- optical recording
- recording medium
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- 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
- G11B11/10576—Disposition or mounting of transducers relative to record carriers with provision for moving the transducers for maintaining alignment or spacing relative to the carrier
-
- 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
- G11B11/10502—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 characterised by the transducing operation to be executed
- G11B11/10528—Shaping of magnetic domains, e.g. form, dimensions
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- 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
- G11B11/10582—Record carriers characterised by the selection of the material or by the structure or form
- G11B11/10584—Record carriers characterised by the selection of the material or by the structure or form characterised by the form, e.g. comprising mechanical protection elements
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- 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
- G11B11/10595—Control of operating function
- G11B11/10597—Adaptations for transducing various formats on the same or different carriers
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/007—Arrangement of the information on the record carrier, e.g. form of tracks, actual track shape, e.g. wobbled, or cross-section, e.g. v-shaped; Sequential information structures, e.g. sectoring or header formats within a track
- G11B7/0079—Zoned data area, e.g. having different data structures or formats for the user data within data layer, Zone Constant Linear Velocity [ZCLV], Zone Constant Angular Velocity [ZCAV], carriers with RAM and ROM areas
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/24—Record carriers characterised by shape, structure or physical properties, or by the selection of the material
- G11B7/2407—Tracks or pits; Shape, structure or physical properties thereof
- G11B7/24085—Pits
Definitions
- the present invention describes a magneto-optical device that has both ROM (Rad On On Memory) by optical phase pits formed on the substrate and R (R andom Access Memory) by a magneto-optical recording film.
- the present invention relates to a recording medium and a magneto-optical recording device, and more particularly to a magneto-optical recording medium and a magneto-optical recording device for reproducing both of them well. Background art
- Fig. 21 is a plan view of a conventional ISO standard magneto-optical disk
- Fig. 22 is an enlarged view of the user area
- Fig. 23 is a cross-sectional view
- Fig. 24 is a diagram showing the relationship between phase pits and MO signals. It is.
- the magneto-optical disk 70 is divided into a lead-in area 71, a lead-out area 72, and a user area 73.
- the lead-in area 71 and the lead-out area 72 are ROM areas composed of phase pits formed by irregularities on a polycarbonate substrate. The depth of the phase pits serving as the ROM area is set so that the light intensity modulation during reproduction is maximized.
- the area between the lead-in area 71 and the lead-out area 72 is a user area 73, which is a RAM area where the user can freely record information.
- a group serving as a tracking guide, a land 75 sandwiched between 74, a phase pit 78 serving as a header part 76 and a user data part 77 are provided. I have.
- the user data section 77 is a flat land 75 sandwiched between groups 74, and is recorded as a magneto-optical signal.
- the magneto-optical recording medium 74 capable of simultaneous reproduction by R ⁇ M_RAM has a radial cross-sectional structure shown in FIG. 23.
- the R ⁇ M information is fixedly recorded by the phase pit PP on the substrate 74A, and the RAM information OMM is recorded in the phase pit PP row. It is recorded by magneto-optical recording.
- the cross section along the line AB in the radial direction in Fig. 24 corresponds to Fig. 23.
- the phase pit PP serves as a tracking guide, the group 74 shown in Fig. 22 is not provided.
- the light intensity modulation that occurs when reading the ROM information is one of the causes of the noise in the RAM information reproduction.
- the applicant has filed an international application filed under PCT / 'JP 02 Z 0 0 159 (international filing date January 01, 2002) with the light intensity associated with the reading of ROM information.
- the degree of light intensity modulation of the ROM information is large, there is a problem that the noise reduction effect is not sufficient by itself.
- an object of the present invention is to provide a magneto-optical recording medium and a magneto-optical recording apparatus for stably and simultaneously reproducing ROM information comprising phase pits and RAM information by magneto-optical recording. To provide.
- Another object of the present invention is to provide a magneto-optical recording medium and a magneto-optical recording device for suppressing the jitter of the ROM information and the reproduction signal of the RAM information within a predetermined range depending on the structure of the recording medium. It is in.
- Another object of the present invention is to provide a magneto-optical recording medium which suppresses jitter of a reproduced signal of ROM information and RAM information within a predetermined range, does not generate cracks, and has sufficient repetitive recording durability. And a magneto-optical recording device.
- a magneto-optical recording medium and apparatus comprise a magneto-optical recording thin film formed on an optical phase pit formed on a substrate, and a phase pit signal and a recording film formed thereon.
- a magneto-optical recording medium capable of reproducing both of the signals described above has an optical depth X ( ⁇ ) of a phase pit formed on a substrate, and a light beam having a polarization direction perpendicular to a track of the magneto-optical recording medium. Assuming that the modulation degree of the phase pit upon irradiation is Y (%), the following condition is satisfied.
- the optical depth of the phase pit is X (E) and the modulation degree is ⁇ (%), the following conditions are satisfied.
- the jitter between the ⁇ signal and the phase pit signal can be suppressed to 8% or less, which has more margin.
- the above-mentioned thin films are a dielectric thin film and a recording film, and more preferably, the dielectric thin film is SIN, whereby a magneto-optical medium having excellent durability performance can be realized.
- FIG. 1 is a sectional view of a magneto-optical recording medium used in one embodiment of the present invention.
- FIG. 2 is a perspective view illustrating a recording state of the R ⁇ M information and the RAM information in the magneto-optical recording medium shown in FIG.
- FIG. 3 is a configuration diagram of a sputtering apparatus for manufacturing the magneto-optical recording medium of FIG.
- FIG. 4 is a diagram showing the relationship between the Ar flow rate in FIG. 3 and the pressure inside the chamber.
- FIG. 5 is an explanatory diagram of a modulation factor to be evaluated in the present invention.
- FIG. 6 is an explanatory diagram of signal jitter to be evaluated in the present invention.
- FIG. 7 is a diagram showing the relationship between the Ar pressure and the degree of modulation according to the present invention.
- FIG. 8 is a diagram illustrating the relationship between the modulation factor, the ROM signal, and the RAM signal jitter according to the present invention.
- FIG. 9 is a diagram showing the relationship between Ar pressure and signal jitter according to the present invention.
- FIG. 10 is a diagram showing the relationship between the results of crack observation by the heat shock test according to the present invention.
- FIG. 11 is a diagram showing the relationship between the optical phase pit depth and the degree of modulation according to the present invention.
- FIG. 12 is a relationship diagram showing a setting range of the optical phase pit depth and the modulation degree according to the present invention.
- FIG. 13 is a sectional view of a magneto-optical recording medium according to another embodiment of the present invention.
- FIG. 14 is an overall block diagram of the configuration of one embodiment of the magneto-optical recording device of the present invention.
- FIG. 15 is a detailed view of the optical system of the optical pickup of FIG.
- FIG. 16 is a partially detailed block diagram of FIG.
- FIG. 17 is a layout diagram of the optical detectors of FIGS. 15 and 16.
- Fig. 18 is a diagram illustrating the relationship between the output of the optical detector in Fig. 17 and focus error (FES) detection, track error (TES) detection, M ⁇ signal and LD feedback signal based on the output. It is.
- FES focus error
- TES track error
- FIG. 19 is a diagram showing the alignment of the detection of ROM and RAM in each of the reproduction and recording modes in the main controller shown in FIGS. 14 and 16.
- FIG. 20 is a block diagram of another embodiment of the magneto-optical recording device of the present invention.
- FIG. 21 is a plan view of a conventional magneto-optical recording medium.
- FIG. 22 is an explanatory diagram of the user area in FIG.
- FIG. 23 is a sectional view of the ROM-RAM magneto-optical disk memory shown in FIG.
- FIG. 24 is a plan view illustrating a recording state of ROM information and RAM information in the magneto-optical recording medium having the structure of FIG. BEST MODE FOR CARRYING OUT THE INVENTION
- FIG. 1 is a cross-sectional view of a concurrent magneto-optical recording medium according to an embodiment of the present invention
- FIG. 2 is a diagram showing the relationship between the R ⁇ M signal and the RAM signal.
- the structure of the magneto-optical disk 4 for providing the user area with the functions of ROM and RAM consists of silicon nitride (SiN) on a polycarbonate substrate 4A on which phase pits 1 are formed.
- First dielectric layer 4B made of chromium, tantalum oxide, etc., amorphous alloy of rare earth (Tb, Dy, Gd) and transition metal (FeCo) such as TbFeCo, GdFeCo
- a second dielectric layer 4F made of the same or different material as the first dielectric layer 4B, and a reflection layer made of a metal such as Au. This is the configuration of the protective coating layer using 4G and UV curable resin.
- the ROM function is provided by the phase pits 1 formed on the disk 4 in an uneven manner
- the RAM function is provided by the magneto-optical recording layers 4C and 4D.
- a laser beam is heated on the magneto-optical recording layers 4C and 4D to assist magnetization reversal, and the direction of magnetization is reversed in response to a signal magnetic field.
- the readout of the recorded information of the magneto-optical recording layers 4C and 4D is performed by irradiating the recording layers 4C and 4D with a weak laser beam so that the polarization plane of the laser light is reduced as much as possible by the recording layers 4C and 4D. It changes according to the direction of magnetization of D, and the presence or absence of a signal is determined based on the strength of the polarization component of the reflected light at this time. Thereby, reading of the RAM information is possible. In this readout, the reflected light is modulated by the phase pits PP that make up the ROM Therefore, reading of ROM information can be performed at the same time.
- ROM and RAM can be reproduced simultaneously by one optical pickup, and if magnetic field modulation type magneto-optical recording is adopted, writing to RAM and reproduction of ROM can be performed simultaneously.
- FIG. 3 is an explanatory diagram of a sputtering film forming apparatus for manufacturing the concurrent magneto-optical medium of FIG. 1, and FIG. 4 is a diagram showing a relationship between the Ar flow rate and the pressure in the chamber.
- Optical depth Five polycarbonate substrates 4 A having different Pd were prepared. That is, five polycarbonate substrates 4 having phase pit optical depths P d ( ⁇ ) of 0.070, 0.080, 0.105, 0.124, and 0.136 were prepared.
- the pit depth was changed according to the resist coating film thickness in the stamper manufacturing process of the stamper for forming phase pits on the substrate 4A.
- this substrate 4A is introduced into a sputtering apparatus 50 having a plurality of film forming chambers having a degree of ultimate vacuum of 5 ⁇ e ⁇ 5 (Pa) or less.
- the substrate 4A is transported to the first chamber 50 where the Si target 56 is mounted, Ar gas and N2 gas are introduced, DC power of 3 kW is applied, and undercoating is performed by reactive sputtering.
- UC reactive sputtering
- the inside of the sputtering chamber 50 is evacuated to about 5 ⁇ e ⁇ 5 (Pa) by a vacuum pump 51 such as a cryopump. Open the substrate transfer gates 54, 55 and insert the substrate 4A from the adjacent chamber. Ar gas and N 2 gas are introduced into the submerged chamber 50 through the Ar gas pipe 53 and the N 2 gas pipe 52. At this time, the gas pressure in the sputtering chamber 150 is adjusted by changing the flow rate of the Ar gas.
- the relationship between the Ar gas flow rate and the pressure varies depending on the size and shape of the sputtering chamber 50 as shown in FIG. 4, but the relationship is approximately proportional.
- Power is supplied to the Si target 56 from a DC power supply (not shown). Plasma is generated by the input electric power and the Ar gas, Si jumps out of the Si target 56, and reacts with the N2 gas. In response, it adheres to the substrate 4A, and the S11 ⁇ layer 48 is formed on the substrate 4A.
- the substrate 4A was moved to another chamber, the TbFeCo target was discharged, and the input power ratio was changed to record a 30 nm thick film of Tb22 (FeC.12) 78.
- Layer 4C was deposited.
- a Tb22 (Fe88Col2) 78, 30 nm thick recording layer 4C, and a 4 nm thick Gdl9 (Fe88Co20) 81 recording auxiliary layer 4D were applied as shown in FIG.
- the substrate 4A was moved to the first chamber 150, and a 5 nm SiN overcoat layer 4F and a 50 nm Al layer 4G were formed.
- An ultraviolet-curing resin coat was applied thereon, thereby producing a magneto-optical recording medium 4 shown in FIG.
- Measurements were made with the modulation degree during R ⁇ M reproduction and jitter measured for 35 samples (magneto-optical disks formed at seven different gas pressures for substrates with five different pit optical depths) with this configuration. .
- This sample was transferred to a recording / reproducing device (MO tester; Shibasoku LM530C) with a beam diameter of 1.08 m (l / e2), a wavelength of 6.50 ⁇ , and a NA (Numerical Apature) of 0.55. 4. Rotated to a linear speed of 4. Sm / s.
- a phase pit (the same pattern as the Compact Disk) of the EFM modulation with the shortest mark of 0.832 ⁇ is formed.
- the modulation was measured under the following recording conditions, reproduced under the following reproduction conditions, and the modulation was measured as shown in FIG.
- the ROM playback waveform was measured with an oscilloscope and the track level was turned on on the medium shown in Fig. 2, and the reflection level when the playback beam was irradiated to the area without the phase pit 1 (space area) (the space area in Fig. 5) Reflection
- the read output level of the ROM signal (the mark level reflection level in Fig. 5) was measured when the read beam was applied to the area where the phase pit 1 (mark) and the phase pit 1 were located. As shown in Fig. 5, the modulation depth was defined as 100 XbZa (%).
- the jitter was measured by the ROM jitter due to the phase pit and the 1 ⁇ 1 ⁇ ] ⁇ ⁇ reproduction jitter.
- the jitter as shown in Fig. 6 was measured for data to data using a time interval analyzer. Jitter is the size of the error of the detected mark length with respect to the target mark length. If the jitter is large, error correction cannot be performed, and a reproduction error occurs.
- Fig. 7 shows the dependency of the modulation degree on the Ar pressure when forming the SIN undercoat layer for each substrate (five types of substrates) with different phase pit depths.
- the modulation degree is high at the low Ar pressure side, and conversely, the modulation degree is low at the high Ar pressure side. It can be seen that adjustment is possible.
- the modulation degree can be adjusted by changing the Ar pressure setting of the SiN undercoat layer.
- the tendency of this change is almost the same regardless of the optical depth of the phase pit on the substrate.
- the optical depth of the phase pits is determined by AFM (Atomic Force Microscope) ⁇ (1 3 ⁇ 4 3 ⁇ 4 ⁇ ⁇ ⁇ ⁇ ⁇ j 7 7 7 7 7 7 7 7 ⁇ ⁇ ⁇ ⁇ 7 7) after molding the substrate.
- the reason why the modulation degree of the phase pits of the magneto-optical disk is changed by the Ar pressure of the SIN undercoat layer is presumed to be that the phase pits of the substrate are processed by the Ar sputtering.
- the Ar pressure setting level By changing the Ar pressure setting level, the plasma state in the film forming chamber is changed, which changes the processing conditions of the phase pits on the substrate surface.
- the modulation degree can be adjusted. That is, the shape of the phase pit can be substantially processed in the film forming process.
- FIG. 8 shows the case where the ROM jitter and ROJVLhMO (R AM) signal jitter of the seven magneto-optical disk medium samples from 10 (%) to 37 (%) in Fig. 7 were measured as described above.
- FIG. 4 is a diagram illustrating the relationship between the modulation factor and jitter. Jitter converted the measured value of data to data described above to the measured value of clock to data.
- the modulation depth should be set to 16% to 30%. More preferably, the modulation factor is 19 to obtain a jitter of 8% or less. /. It should be set to ⁇ 26%.
- FIG. 9 is a diagram showing the relationship between the jitter of the MO (RAM) signal on the ROM and the Ar pressure when the undercoat layer is formed. Jitter measured the initial jitter and the jitter after 100,000 continuous recording tests.
- the A 1 -pressure may be set to 0.5 Pa or more.
- a heat shock test was performed on a sample in which each layer including the SiN undercoat layer was formed on the substrate 4A, and the occurrence of cracks in the medium was observed.
- multiple samples of Ar under pressure were formed for the formation of a plurality of SIN undercoat layers. The samples were maintained at room temperature from 100 ° C for 1 hour, then returned to room temperature and observed for cracks. did.
- the Ar pressure is 2.0 Pa or less in a range in which no cracks occur in the SiN undercoat layer. From the above results of Fig. 8, Fig. 9 and Fig. 10, in order to obtain good signal quality for both ROM signal and RAM (MO on ROM) signal without cracks, the conditions in the frame of Fig. It can be seen that it should be set.
- the Ar pressure may be set between 0.7 and 2.0 (Pa).
- the Ar pressure may be adjusted between 0.5 and 1.5 (Pa).
- the modulation depth cannot be set to 16 to 30% even if the Ar pressure is set between 0.5 and 2.0 (Pa).
- the modulation depth is in the range of 16% to 30% at any value of 0.5 to 2.0 (Pa).
- the condition under which the jitter of the ROM signal and the RAM signal are both optimal is a modulation factor of 23%. In this board, by setting the Ar pressure to 0.6 to 1. OPa, a higher level of quality can be achieved. It is also possible to realize
- FIG. 11 shows the result of plotting the change of the modulation degree with respect to the depth of the optical phase pit for each Ar pressure at the time of forming the undercoat SiN, which is opposite to FIG.
- the modulation degree is adjusted by adjusting the 1 "pressure in the range of 0.5 to 0.9 (Pa).
- the modulation can be adjusted within the range of 16 to 30%, and preferably, the modulation degree can be adjusted to approximately 19% by setting the Ar pressure to 0.5 (Pa).
- the undercoat S i Ar Ar pressure during film formation is set within the range of 0.9 to 2.0 (Pa). Modulations in the range of 16-30% are obtained. Further, preferably, by setting the Ar pressure to 2.0 (Pa), a modulation degree of approximately 26% can be obtained.
- a modulation degree of 16 to 30% can be obtained when the Ar pressure is in the range of 0.5 to 2.0 (Pa). Further, preferably, by adjusting the pressure within the range of 0.65 to 1.5 (Pa), a modulation degree of 19 to 26% can be obtained.
- the adjustable range of the modulation degree becomes narrow, and a modulation degree of 19 to 26% cannot be realized.
- the modulation depth adjustable range is narrowed, and a modulation depth of 19 to 26% cannot be achieved.
- FIG. 12 is a characteristic diagram in which the repetitive recording characteristic of FIG. 9 and the crack occurrence of FIG.
- Fig. 12 shows a magneto-optical medium capable of simultaneously reproducing ROM and RAM that has good jitter of 10% or less for both ROM and RAM signals, has no cracks, and has sufficient repetitive recording durability.
- the setting range of the phase pit depth and modulation that can be realized is shown.
- Fig. 12 shows the straight line 1 from the repetition characteristics of Fig. 9 and the heat shock test of Fig. 10. Line 2 was determined from the crack observation results of the experiment. Therefore, from FIG. 12, the aforementioned setting range is within the following two linear ranges 1 and 2, and the optical depth of the phase pit is 0.080 ⁇ to 0.124 ⁇ , and the modulation degree is 16 to 30%. , Preferably in the range of 19-26%.
- the sputter deposition process using Si was described as an example, but other materials may be used as long as the modulation degree can be similarly adjusted.
- materials such as Si02, A1N, SiA10, SiA10N, and TaO may be used.
- FIG. 13 is a cross-sectional view of a magneto-optical recording medium 4 according to another embodiment of the present invention, and shows a medium for MSR (super-resolution recording).
- the magneto-optical recording layer provided on the first dielectric layer 4B on the substrate 4A includes a GdFeCo layer (in-plane) 4D, a dielectric layer 4E, and a perpendicular recording layer (TbFeCo) layer 4C.
- the conditions such as the phase pit small optical depth and the modulation degree described in FIG.
- the recording density is high, so even if the light intensity modulation signal is negatively fed back to the light emitting laser, the noise cannot be reduced, so that the effect is particularly remarkable.
- a magneto-optical recording thin film is formed on an optical phase pit formed on a substrate, and magneto-optical recording capable of reproducing both a phase pit signal and a signal of a recording film formed thereon is performed.
- the optical depth of the phase pits formed on the substrate is X (e) and the modulation degree is Y (%), the following conditions are satisfied.
- the optical depth of the phase pit is X (e) and the modulation degree is ⁇ (%), the following conditions are satisfied.
- the jitter between the M ⁇ signal and the phase pit signal can be suppressed to 8% or less, which has more margin.
- the above-mentioned thin films are a dielectric thin film and a recording film, and more preferably, the dielectric thin film is SIN, whereby a magneto-optical medium having excellent durability performance can be realized.
- the recording layer is composed of a thin film mainly composed of TbFeCo, and preferably, the recording layer is at least two layers of a layer mainly composed of a TbFeCo layer and a layer mainly composed of a GdFeCo layer. It is also desirable that the GdFeCo layer be a transition metal dominant and a perpendicular magnetization film at room temperature.
- a magneto-optical recording device disk drive according to the present invention will be described.
- FIG. 14 is an overall block diagram of an optical disk drive according to an embodiment of the present invention
- FIG. 15 is a configuration diagram of an optical system of the drive of FIG. 14
- FIG. 16 is a signal processing of the drive of FIG.
- Fig. 17 is a block diagram of the science system
- Fig. 17 is a layout diagram of the detectors in Fig. 15 and Fig. 16
- Fig. 18 is a diagram showing the relationship between the output of the detector and generated signals
- the motor 18 rotates the magneto-optical recording medium (MO disk) 4.
- MO disk 4 is a removable medium, and is inserted from an input location of a drive (not shown).
- the optical pickup 5 has a magnetic head 35 and an optical head 7 arranged so as to sandwich the optical information recording medium 4.
- the optical pickup 5 is moved by a track actuator 6 such as a ball screw feed mechanism, and can access any position in the radial direction of the optical information recording medium 4. Further, an LD driver 31 for driving the laser diode LD of the optical head 7 and a magnetic head driver 34 for driving the magnetic head 35 of the optical pickup 5 are provided.
- the access servo controller 15 _ 2 servo-controls the track actuator 6, the motor 18, and the focus actuator 19 of the optical head 7 based on the output from the optical head 7.
- the controller 15-1 operates the LD driver 31, the magnetic head drino 34, and the access servo controller 15-2 to record and reproduce information. Details of the optical head 7 will be described with reference to FIG.
- the diverging light from the laser diode LD passes through the three-beam tracking diffraction grating 10 and the beam splitter 11 to become collimated light by the collimator lens 39, is reflected by the mirror 40, and is then recorded by the objective lens 16 for optical information recording.
- the light is focused on the medium 4 almost to the diffraction limit.
- a part of the light incident on the beam splitter 11 is reflected by the beam splitter 11 and condensed on an APC (Auto Power Control) detector 13 via a condenser lens 12.
- APC Auto Power Control
- the light reflected from the optical information recording medium 4 passes through the objective lens 16 again, is reflected by the mirror 140, becomes convergent light by the collimating lens 39, and is incident on the beam splitter 111 again.
- Part of the light that has re-entered the beam splitter 11 returns to the laser diode LD side, and the remaining light is reflected by the beam splitter 11 to form a three-beam Wollaston prism 26 and a cylindrical lens 21.
- the light is condensed on the reflected light detector 25 via.
- the reflected light detector 25 has three beams of incident light, as shown in FIG. 17, the four-split detector 22-1, the MO signal detector 20 arranged above and below it, and the tracks arranged on the left and right sides thereof It consists of error detection detectors 22-2 and 22-3.
- an FES (Focus Error Signal) reproducing circuit 23 uses the outputs A, B, C, and D of the photoelectrically converted four-segment photodetector 22 to generate a forcing force by the astigmatism method shown in FIG. Error detection (FES). That is,
- a track error detection is performed by the push-pull TES generation circuit 24 from the outputs E and F of the track detection detectors 22-2 and 22-3 using the arithmetic expression in FIG.
- the focus error signal (FES) and track error signal (TES) obtained by these calculations are used as the position error signal in the focus direction and track direction as the main controller 15 (in FIG. 14, the access servo controller 15 -2).
- the access thermocontroller 15-2 and the controller 15-1 are shown as an integrated main controller 15.
- the polarization characteristic of the reflected laser light which changes depending on the direction of magnetization of magneto-optical recording on the optical information recording medium 4, is converted into light intensity. That is, in the three-beam Wollaston 26, the light is separated into two beams whose polarization directions are orthogonal to each other by polarization detection, is incident on the two-segment photodetector 20 through the cylindrical lens 21, and is photoelectrically converted.
- ROM G + H
- MO RAM read
- FIG. 16 the reflected light of the semiconductor laser diode LD incident on the APC photodetector 13 is photoelectrically converted into a main controller 15 and is input as a second ROM signal (ROM 2) through an amplifier 14.
- the main controller 15 includes the first ROM signal (ROM1) output from the addition amplifier 29, the RAM signal (RAM) output from the differential amplifier 30, and the FES generation circuit 23. And a track error signal (TES) from the TES generation circuit 24.
- ROM1 first ROM signal
- RAM RAM signal
- TES track error signal
- recording data and read data are input / output to / from the main controller 15 through the interface circuit 33 with the data source 32.
- the main controller 15 generates a command signal to the LD driver 31 according to each mode.
- the data is input to the main controller 15 through the data interface 33 from the data source 32 (see FIG. 16).
- the main controller 15 supplies the input data to the magnetic head drive 34 when the magnetic field modulation recording method is used.
- the magnetic head driver 34 drives the magnetic head 35 and modulates a magnetic field in accordance with recording data.
- the main controller 15 sends a signal indicating recording at a time to the LD driver 31.
- this input data is sent to the LD driver 31 to drive the laser diode LD for light modulation.
- the forcing singler signal is detected by the astigmatism method
- the tracking error signal is detected by the 3-beam method
- the MO signal is detected from the differential detection signal of the polarization component.
- the system is used in the embodiment of the present invention, and there is no problem in the forcing error detection method such as the knife edge method and the spot size position detection method. There is no problem even if the tracking error detection method uses the push-pull method or the phase difference method! / ,.
- the main controller 15 drives the focus actuator 19 according to the detected focus error signal FES, and controls the focusing of the light beam.
- the main controller 15 (the servo controller 15-2 in FIG. 14) drives the track actuator 6 in accordance with the detected track error signal TESS, and controls the light beam to seek and follow the track.
- FIG. 20 is a block diagram of a magneto-optical recording device according to another embodiment of the present invention. In FIG. 20, the same components as those shown in FIGS. 14 to 16 are represented by the same symbols. In this example, the negative feedback control of the laser diode LD is not performed by the ROM 1 signal (phase pit modulation signal).
- the present invention can be variously modified within the scope of the gist of the present invention within the spirit of the present invention, and these are not excluded from the technical scope of the present invention.
- the size of the phase pit is not limited to the numerical value described above, and other sizes can be applied.
- other magneto-optical recording materials can be applied to the magneto-optical recording film.
- the magneto-optical recording medium is not limited to the disk shape but may be a card shape or the like. Industrial applicability
- a magneto-optical recording thin film is formed on an optical phase pit formed on a substrate, and a phase pit signal and a signal of a recording film formed thereon are reproduced on a magneto-optical recording medium capable of reproducing both signals.
- the optical depth of the phase pit is X ( ⁇ ) and the modulation is Y (%), the following conditions are satisfied.
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Priority Applications (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AU2003213460A AU2003213460A1 (en) | 2003-03-12 | 2003-03-12 | Magneto-optical recording medium and magneto-optical recording device |
JP2004569336A JPWO2004081930A1 (ja) | 2003-03-12 | 2003-03-12 | 光磁気記録媒体及び光磁気記録装置 |
PCT/JP2003/002888 WO2004081930A1 (ja) | 2003-03-12 | 2003-03-12 | 光磁気記録媒体及び光磁気記録装置 |
CN03826136.7A CN1759443A (zh) | 2003-03-12 | 2003-03-12 | 磁光记录介质和磁光记录装置 |
US11/123,951 US20050201263A1 (en) | 2003-03-12 | 2005-05-06 | Magneto-optical recording medium and a magneto-optical recording device thereof |
Applications Claiming Priority (1)
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PCT/JP2003/002888 WO2004081930A1 (ja) | 2003-03-12 | 2003-03-12 | 光磁気記録媒体及び光磁気記録装置 |
Related Child Applications (1)
Application Number | Title | Priority Date | Filing Date |
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US11/123,951 Continuation US20050201263A1 (en) | 2003-03-12 | 2005-05-06 | Magneto-optical recording medium and a magneto-optical recording device thereof |
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WO2004081930A1 true WO2004081930A1 (ja) | 2004-09-23 |
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JP (1) | JPWO2004081930A1 (ja) |
CN (1) | CN1759443A (ja) |
AU (1) | AU2003213460A1 (ja) |
WO (1) | WO2004081930A1 (ja) |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH06162590A (ja) * | 1992-11-20 | 1994-06-10 | Sony Corp | 光ディスク |
JPH09102142A (ja) * | 1995-10-02 | 1997-04-15 | Fujitsu Ltd | 光記録媒体及びその製造方法 |
JP2001067812A (ja) * | 1999-06-21 | 2001-03-16 | Fujitsu Ltd | 光記録媒体、データブロック識別マークの検出方法及び光記憶装置 |
JP2002197725A (ja) * | 2000-12-22 | 2002-07-12 | Sony Corp | 記録媒体および記録媒体原盤ならびに記録媒体の製造方法 |
-
2003
- 2003-03-12 JP JP2004569336A patent/JPWO2004081930A1/ja active Pending
- 2003-03-12 WO PCT/JP2003/002888 patent/WO2004081930A1/ja active Application Filing
- 2003-03-12 AU AU2003213460A patent/AU2003213460A1/en not_active Abandoned
- 2003-03-12 CN CN03826136.7A patent/CN1759443A/zh active Pending
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH06162590A (ja) * | 1992-11-20 | 1994-06-10 | Sony Corp | 光ディスク |
JPH09102142A (ja) * | 1995-10-02 | 1997-04-15 | Fujitsu Ltd | 光記録媒体及びその製造方法 |
JP2001067812A (ja) * | 1999-06-21 | 2001-03-16 | Fujitsu Ltd | 光記録媒体、データブロック識別マークの検出方法及び光記憶装置 |
JP2002197725A (ja) * | 2000-12-22 | 2002-07-12 | Sony Corp | 記録媒体および記録媒体原盤ならびに記録媒体の製造方法 |
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AU2003213460A1 (en) | 2004-09-30 |
JPWO2004081930A1 (ja) | 2006-06-15 |
CN1759443A (zh) | 2006-04-12 |
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