WO2010026744A1 - 情報記録媒体の初期化方法、情報記録媒体の初期化装置および情報記録媒体 - Google Patents
情報記録媒体の初期化方法、情報記録媒体の初期化装置および情報記録媒体 Download PDFInfo
- Publication number
- WO2010026744A1 WO2010026744A1 PCT/JP2009/004316 JP2009004316W WO2010026744A1 WO 2010026744 A1 WO2010026744 A1 WO 2010026744A1 JP 2009004316 W JP2009004316 W JP 2009004316W WO 2010026744 A1 WO2010026744 A1 WO 2010026744A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- light beam
- recording medium
- information
- initialization
- information recording
- Prior art date
Links
Images
Classifications
-
- 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
- G11B7/2403—Layers; Shape, structure or physical properties thereof
- G11B7/24035—Recording layers
- G11B7/24038—Multiple laminated recording layers
-
- 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
- G11B7/12—Heads, e.g. forming of the optical beam spot or modulation of the optical beam
- G11B7/125—Optical beam sources therefor, e.g. laser control circuitry specially adapted for optical storage devices; Modulators, e.g. means for controlling the size or intensity of optical spots or optical traces
- G11B7/127—Lasers; Multiple laser arrays
- G11B7/1275—Two or more lasers having different wavelengths
-
- 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
- G11B7/26—Apparatus or processes specially adapted for the manufacture of record carriers
- G11B7/268—Post-production operations, e.g. initialising phase-change recording layers, checking for defects
-
- 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
- G11B2007/0003—Recording, reproducing or erasing systems characterised by the structure or type of the carrier
- G11B2007/0009—Recording, reproducing or erasing systems characterised by the structure or type of the carrier for carriers having data stored in three dimensions, e.g. volume storage
- G11B2007/0013—Recording, reproducing or erasing systems characterised by the structure or type of the carrier for carriers having data stored in three dimensions, e.g. volume storage for carriers having multiple discrete layers
Definitions
- the present invention relates to an information recording medium on which information is recorded and / or reproduced (hereinafter referred to as recording / reproduction) by irradiation with a laser beam or the like, and in particular, an initialization method for an information recording medium having a multilayer recording film, and information recording
- the present invention relates to a medium initialization apparatus and an information recording medium thereof.
- phase change type information recording medium capable of recording, erasing and rewriting information on a recording film by optical means using laser light.
- Recording, erasing, and rewriting of the phase change information recording medium utilize the fact that the phase change material causes a reversible change between crystal and amorphous in the recording film.
- information recording is performed by forming a recording mark by making a part of the recording film amorphous (erasing), and erasing is performed by crystallizing the recording mark. It is what is done.
- Amorphization is performed by heating the recording film to the melting point or higher and then rapidly cooling it.
- the crystallization is performed by heating the recording film to a temperature not lower than the crystallization temperature and not higher than the melting point, or by gradually cooling after heating to the melting point or higher.
- phase change type information recording medium there is a “Blu-ray Disc” information recording medium which can be said to be commercialized at present.
- This "Blu-ray Disc” is used as an information recording medium compatible with digital high-definition broadcasting (High definition televisoin), and has a recording capacity of 25 GB (single layer) and 50 GB (single-sided dual layer). And a transfer rate of 36 Mbps (1 ⁇ speed).
- a recording film material of the 1 ⁇ speed rewritable Blu-ray Disc for example, a solid solution between GeTe and Sb 2 Te 3 (see Patent Document 1) or between GeTe and Bi 2 Te 3 in which Sb is replaced with Bi. A solid solution (see Patent Document 2) is used.
- a sputtering method is generally used for forming the recording film, the reflective film, and the dielectric film.
- the phase change thin film formed by this sputtering method is in an amorphous state (amorphous state). Therefore, in “Blu-ray Disc”, it is necessary to crystallize the entire recording film in the data area of the information recording medium before recording information. The process of crystallizing the entire recording film from the amorphous state in this way is called initialization.
- FIG. 9 is a schematic diagram showing a general configuration of a conventional initialization apparatus.
- the information recording medium 209 is irradiated with the light beam A from the optical head 200, and the recording film of the information recording medium 209 is initialized.
- the output power of the light source 201 that emits the light beam A having a wavelength of 810 nm is controlled by the laser driving circuit 208.
- the light beam A emitted from the light source 201 passes through the optical path correction unit 206 and the collimator lens 207 and is reflected by the beam splitter 203.
- the light beam A reflected by the beam splitter 203 passes through the objective lens 205 and irradiates the information recording medium 209.
- the light beam A reflected by the recording film of the information recording medium 209 passes through the objective lens 205 again and enters the focus error detector 210.
- an electric signal indicating the light beam A detected by the focus error detector 210 is input to the focus error signal generation circuit 211.
- the focus error signal circuit 211 forms a focus error signal and outputs the focus error signal to the focus servo circuit 212.
- the focus servo circuit 212 adjusts the position of the objective lens 205 by driving the voice coil 204 based on the focus error signal. In this manner, the focus servo circuit 212 drives the voice coil 204 to adjust the position of the objective lens 205, so that the light beam A is focused on a predetermined recording film on the information recording medium 209.
- the laser drive circuit 208 and the focus servo circuit 212 are controlled by the controller 213. (See Patent Document 3)
- Patent Document 3 discloses an initialization method for an information recording medium having two information layers as an information layer having a recording film using the initialization apparatus having the above-described configuration.
- FIG. 10 is a cross-sectional view showing an example of a schematic configuration of a multilayer information recording medium.
- a multilayer information recording medium 300 shown in FIG. 10 is a cross-sectional view of a multilayer information recording medium having four information layers.
- a multilayer information recording medium 300 shown in FIG. 10 includes a first information layer 302, a first transparent separation layer 303, a second information layer 304, and a second transparent separation layer 305 on a substrate 301 formed of polycarbonate. , A third information layer 306, a third transparent separation layer 307, a fourth information layer 308, and a cover layer 309 made of an ultraviolet effect resin.
- a recording film is formed on each information layer.
- the recording / reproducing light beam is irradiated from the cover layer 309 side, and recording / reproducing is performed on the recording film of each information layer.
- the sputtering method is used for film formation, and it is a phase change thin film in each information layer (302, 304, 306, 308) formed by the sputtering method.
- the recording film is almost in an amorphous state (amorphous state). Therefore, before recording information, it is necessary to crystallize the entire data area which is the recording / reproducing area in the recording film of the multilayer information recording medium in advance.
- Patent Document 3 described above discloses an initialization method for an information recording medium having two information layers as a plurality of information layers.
- initialization for an information recording medium having a plurality of information layers having three or more information layers that is, a so-called multilayer information layer
- the initialization method disclosed in Patent Document 3 It was very difficult to perform a reliable initialization process.
- an intermediate layer between an information layer (back side information layer) located farthest from the surface on which the light beam is incident and an information layer (front side information layer) located closest to the surface was very difficult.
- the transmittance of each information layer is set high and the thickness is set thin so that the light beam can be surely transmitted through each information layer. For this reason, the amount of reflected light in each information layer decreases, the level of the focus error signal in each information layer decreases, and it is difficult to distinguish it from noise. As a result, it is very difficult to accurately detect the position of each layer in the multilayer information recording medium based on the focus error signal, and it is difficult to reliably identify and initialize each corresponding information layer. It was almost impossible.
- the inventor has considered the initialization method of the multilayer information recording medium 300 having the four information layers (recording films) shown in FIG.
- the present inventor used an optical head which is an optical device that emits a light beam having a wavelength of 810 nm.
- the information layer on the back side which is far from the light beam incident surface from the optical head, is sequentially moved toward the front side, which is near the light beam incident surface.
- This is an efficient and preferred initialization method. Therefore, in the multilayer information recording medium 300 shown in FIG. 10, the first information layer 302, the second information layer 304, the third information layer 306, and the fourth information layer 308 are arranged in this order on the substrate 301 side (light Initialization processing is sequentially performed from the information layer farthest from the beam incident surface to the cover layer 309 side (front side close to the light beam incident surface).
- the light beam in order to irradiate the first information layer 302 farthest from the incident surface of the light beam, the light beam is irradiated with the second information layer 304, the third information layer 306, and the fourth information layer. Go through 308. In this way, each time the light beam passes through the second information layer 304, the third information layer 306, and the fourth information layer 308, the light beam from the optical head gradually attenuates. Therefore, when the light beam is applied to the first information layer 302 farthest from the light beam incident surface in the multilayer information recording medium 300 as compared with a single-layer information recording medium having only one information layer. The amount of reflected light from the first information layer 302 is significantly reduced.
- the other information layers 304, 306, and 308 are also made of a material having high transmittance because it is necessary to suppress attenuation that occurs when the light beam passes through the information layers 304, 306, and 308. . Therefore, the amount of reflected light from each information layer 304, 306, 308 is naturally small. In the experiment by the present inventor, the amount of reflected light from each information layer 304, 306, 308 is small when a light beam having a wavelength of 810 nm is irradiated onto the multilayer information recording medium 300, and the threshold value is set in advance. Therefore, it is very difficult to distinguish the detected focus error signal from noise.
- 11A to 11E show focus error signals when the information recording medium 300 having the four information layers shown in FIG. 10 is irradiated with a light beam (infrared color) having a wavelength of 810 nm.
- the multilayer information recording medium 300 used here is an information recording medium that records and reproduces information using a light beam of 405 nm (400 to 410 nm).
- the second information layer 304 and the third information layer 306 are initialized, but these are initialized immediately after each information layer is experimentally formed.
- FIG. 11A is a focus error signal detected in a state before all the information layers 302, 304, 306, and 308 are initialized.
- the level of the focus error signal of the first information layer 302 farthest from the light beam incident surface in the multilayer information recording medium 300 has a high value.
- the amount of reflected light is relatively large because the light beam does not need to pass through the information layer.
- the amount of reflected light may be greater before initialization than after initialization.
- FIG. 11B shows a focus error signal in a state after initializing the first information layer 302 and before initializing the next second information layer 304. That is, the focus error signal shown in FIG. 11B is a state in which the second information layer 304, the third information layer 306, and the fourth information layer 308 are not initialized.
- the level of the focus error signal in the second information layer 304 is very low. Therefore, it is not easy to focus on the position of the second information layer 304, and it is difficult to reliably initialize the second information layer 304.
- FIG. 11C shows a focus error signal in a state after initializing the first information layer 302 and the second information layer 304 and before initializing the next third information layer 306. That is, the focus error signal shown in FIG. 11C is a state in which the third information layer 306 and the fourth information layer 308 are not initialized. As shown in FIG. 11C, since the amount of reflected light from the third information layer 306 is small, the level of the focus error signal in the third information layer 306 is very low.
- FIG. 11D shows the focus in a state after the first information layer 302, the second information layer 304, and the third information layer 306 are initialized and before the next fourth information layer 308 is initialized. Indicates an error signal. As shown in FIG. 11D, since the amount of reflected light from the fourth information layer 308 is small, the level of the focus error signal in the fourth information layer 308 is very low.
- FIG. 11E shows a focus error signal when a light beam having a wavelength of 810 nm is irradiated in a state where all the information layers 302, 304, 306, and 308 are initialized.
- the level in the information layer to be initialized is low. Therefore, it is not easy to focus the light beam at the position of the information layer (recording film), and it is very difficult to reliably initialize the information layer (recording film).
- the experimental results as described above were performed using a light beam (red) having another wavelength, for example, a wavelength of 680 nm, and the same result was obtained.
- Patent Document 3 in an initialization process of an information recording medium having two information layers, the information layer on the back side (information layer far from the optical beam incident surface) in the two information layers is initialized. Before the information layer on the near side (information layer on the side close to the optical beam incident surface) is initialized, the position of the region where the near information layer exists (with a thickness of 100 ⁇ m) is specified, and A method for initializing a part of a side information layer is disclosed.
- the initialization method disclosed in Patent Document 3 assumes that an area where the information layer exists is assumed before the initialization process of the information layer to be initialized, It is conceivable that the information layer is partially initialized by irradiating the activating light beam.
- an initialization processing method is possible for an information recording medium having two information layers, but for a multilayer information recording medium having three or more information layers, initialization is performed for the following reason. Processing is very difficult and nearly impossible.
- the thickness of each transparent separation layer 303, 305, 307 is 30 ⁇ m or less. It is very thin. Further, the surface blur, which is a distortion in the multilayer information recording medium 300, is usually 30 ⁇ m or more. Therefore, for example, even if the initialization light beam is irradiated assuming the position of the second information layer 304 as the information layer to be initialized, the third information layer 306 and the fourth information layer 308 are also irradiated. There is a problem in that not only the second information layer 304 but also the third information layer 306 and the fourth information layer 308 are initialized by irradiating the light beam.
- the light beam needs to pass through the third information layer 306 and the fourth information layer 308.
- the power of the light beam is necessarily increased. This causes the third information layer 306 and the fourth information layer 308 to be unnecessarily initialized by the light beam.
- the transmittance of the third information layer 306 and the fourth information layer 308 with respect to the light beam having a wavelength of 810 nm is reduced to about half, which is greatly reduced.
- the amount of reflected light in the second information layer 304 is greatly reduced, and the level of the focus error signal is very low.
- the present invention relates to an initialization method capable of stably and reliably initializing all information layers (recording films) of a multilayer information recording medium having a plurality of information layers, in particular, three or more information layers, It is an object of the present invention to provide an initialization apparatus that executes an initialization method, and a reliable multilayer information recording medium that is reliably initialized.
- An information recording medium initialization method is an initialization method for initializing an information recording medium having at least two information layers, Partially initializing a region of the recording film with a first light beam having an initialization wavelength with respect to the recording film of the information layer; Irradiating a partially initialized region in the recording film with a second light beam having a wavelength corresponding to a wavelength for recording and reproducing information on the information recording medium; Adjusting a focus position based on a focus error signal generated by reflected light from the information layer generated by irradiation of the second light beam; The recording film is initialized by irradiating the information recording medium with the first light beam with the focus position adjusted. According to the initialization method including such steps, the recording films of all the information layers of the multilayer information recording medium can be initialized stably and reliably.
- An information recording medium initialization method includes the step of partially initializing a partial area of the recording film with the first light beam according to the first aspect. 1 light beam partially initializes the focus adjustment initialization area other than the recording / reproduction area in the recording film, In the step of irradiating the information recording medium with the second light beam, the second light beam may be irradiated onto the initialization region for focus adjustment partially initialized.
- the information recording medium initialization method according to the third aspect of the present invention is such that the information recording medium according to the second aspect includes N (where N is an integer of 3 or more) information layers. But you can.
- an information recording medium initialization method wherein the information recording medium according to the first aspect includes N (where N is an integer of 3 or more) information layers.
- N is an integer of 3 or more
- the first information layer In order from the information layer farthest from the beam incident side, the first information layer,..., The nth information layer (where n is an integer and has a relationship of 2 ⁇ n ⁇ N),.
- the first light beam partially initializes a focus adjustment initialization area other than the recording / reproduction area in the recording film
- the second light beam may be irradiated onto the initialization region for focus adjustment partially initialized.
- a method for initializing an information recording medium wherein the first light beam is applied to the recording film in the Nth information layer according to the fourth aspect.
- the first light beam partially initializes a focus adjustment initialization area other than the recording / reproduction area in the recording film
- the second light beam may be irradiated onto the initialization region for focus adjustment partially initialized.
- a method for initializing an information recording medium wherein in the step of partially initializing the focus adjustment initialization area according to the third aspect, the focus of the first light beam is set. May be reciprocated in the thickness direction of the information recording medium to partially initialize all the recording films of the N information layers.
- a method for initializing an information recording medium wherein in the step of partially initializing the focus adjustment initialization area according to the second aspect, the focus of the first light beam is set.
- the power of the first light beam is set to be different between the forward operation direction and the return operation direction of the focus position of the first light beam. Also good.
- an information recording medium initialization method comprising: first focusing the first light beam in the step of partially initializing the focus adjustment initialization area according to the seventh aspect.
- the power of the first light beam when moving closer to the light beam incident side of the information recording medium is the light beam incident side of the information recording medium. You may set larger than the power of the said 1st light beam at the time of the movement which leaves
- the wavelength of the first light beam in the first aspect is preferably in the range of 630 to 850 nm.
- the information recording medium initialization method according to the tenth aspect of the present invention is such that the wavelength of the second light beam in the first aspect is ⁇ the wavelength for recording / reproducing information on the information recording medium. It is preferable to be within the range of 60 nm.
- the wavelength of the second light beam according to the first aspect allows information to be recorded and reproduced on the information recording medium. It is preferable to be within the range of ⁇ 20 nm of the wavelength.
- the information recording medium initialization method according to the twelfth aspect of the present invention is such that the spot size of the second light beam in the first aspect is set smaller than the spot size of the first light beam. Is preferred.
- the spot position of the second light beam in the first aspect is the first light beam with respect to the initialization progress direction. It is preferable to be behind the spot position.
- an information recording medium initialization method in the step of adjusting the focus position of the first light beam in the first aspect to the position of the recording film, The focus position is controlled using the second light beam based on the focus error signal generated based on the reflected light from the recording film, and then switched to the first light beam and performed again. May be.
- An information recording medium initialization method provides the second light beam when the recording film is initialized by the first light beam according to the fourteenth aspect. You may comprise so that the said recording film may not be irradiated.
- an information recording medium wherein the recording film when irradiated with the second light beam according to the sixteenth aspect has an uninitialized reflectance in the initialized state. It is set to be higher than the reflectance. For this reason, in the information recording medium of the seventeenth aspect, when the second light beam irradiates the information recording medium, the reflected light from the initialized recording film is surely generated, and the focus error signal The level is raised.
- the distance between the information layers of the information recording medium in the sixteenth aspect is 30 ⁇ m or less. For this reason, the information recording medium according to the eighteenth aspect is very difficult to cope with by the conventional initialization method, and the initialization method and the initialization apparatus of the present invention enable reliable initialization processing. .
- An information recording medium initialization apparatus is an initialization apparatus for initializing a recording film in an information recording medium
- the initialization device includes at least one optical head for irradiating the recording film with a light beam
- the optical head includes a first light source that emits a first light beam having a wavelength for initialization, and a second light beam having a wavelength corresponding to a wavelength for recording and reproducing information on the information recording medium.
- a second light source that emits light, an objective lens that focuses the first light beam and the second light beam on the recording film, and a focus position control unit that performs focus position control of at least one light beam.
- the recording films of all the information layers of the multilayer information recording medium can be initialized stably and reliably.
- An initialization apparatus may include, in the nineteenth aspect, a mechanism for moving an objective lens for focusing on the recording film in the thickness direction of the information recording medium. Good.
- the wavelength of the first light beam in the nineteenth aspect is preferably in the range of 630 to 850 nm.
- An information recording medium initialization apparatus is directed to an information recording medium initialization apparatus according to the nineteenth aspect, wherein the spot position of the second light beam is the first light beam with respect to the initialization progress direction. It is preferable to be behind the spot position.
- the focus position control unit in the nineteenth aspect controls the focus positions of the first light beam and the second light beam. You may comprise.
- the numerical aperture of the objective lens according to the nineteenth aspect is preferably 0.6 or more.
- the initialization method and initialization apparatus for an information recording medium According to the initialization method and initialization apparatus for an information recording medium according to the present invention, a stable and reliable focus adjustment is performed on a multilayer information recording medium having a plurality of information layers so that all the information layers can be surely obtained.
- the manufacturing yield can be dramatically improved, and the manufacturing cost can be suppressed, so that an inexpensive information recording medium can be provided.
- FIG. 1 is a block diagram showing a schematic configuration of an information recording medium initialization apparatus according to Embodiment 1 of the present invention.
- FIG. 3 is a diagram illustrating a configuration of an optical head in the information recording medium initialization apparatus according to the first embodiment.
- FIG. 6 is a diagram showing the relationship between the spot shapes of the first light beam and the second light beam and the spot position of each light beam in the information recording medium initialization apparatus of the first embodiment.
- Sectional drawing which shows an example of the information recording medium used in the initialization apparatus of the information recording medium of Embodiment 1 Diagram showing an example of focus error signal in the experiment Diagram showing an example of focus error signal in the experiment Diagram showing an example of focus error signal in the experiment Diagram showing an example of focus error signal in the experiment Diagram showing an example of focus error signal in the experiment Diagram showing an example of focus error signal in the experiment Diagram showing an example of focus error signal in the experiment Diagram showing an example of focus error signal in the experiment
- the flowchart which shows the outline of the initialization method in Embodiment 1 of this invention.
- the flowchart which shows the principal part of the initialization method in Embodiment 1 of this invention.
- the flowchart which shows the principal part of the initialization method in Embodiment 2 of this invention.
- the present inventor has conceived that, in the focus adjustment in the initialization process for the multilayer information recording medium, the focus adjustment is performed using the light beam used when recording / reproducing on the information recording medium to be initialized, and the idea Based on the above, the initialization processing experiment described below was conducted to realize the initialization method and the initialization apparatus of the present invention.
- the initialization processing experiment described below the initialization apparatus described in Embodiment 1 described later is used, and a multilayer information recording medium having four information layers as an information recording medium to be initialized (see FIG. 10). ) was used.
- the wavelength of the light beam for recording / reproduction of this multilayer information recording medium is 405 nm.
- FIG. 5A to FIG. 5E show the results of the initialization processing experiment, and show the focus error signal when the multilayer information recording medium is irradiated with a light beam (blue violet) having a wavelength of 405 nm.
- a light beam blue violet
- FIG. 5A is a focus error signal detected in a state before all the information layers 302, 304, 306, and 308 are initialized. As shown in FIG. 5A, the amount of reflected light from all the information layers in the multilayer information recording medium 100 is small, and the level of the focus error signal in each information layer is low.
- the amount of reflected light from the first information layer 302 is reliably detected, and the level of the focus error signal in the first information layer 302 is high. Therefore, it is easy to focus on the position of the recording film of the first information layer 302.
- FIG. 5C shows a focus error signal after the first information layer 302 and the second information layer 304 are partially initialized.
- the focus error signal shown in FIG. 5C partially initializes an area other than the area where data is recorded / reproduced in the first information layer 302 and the second information layer 304 (focus adjustment initialization area). It is a focus error signal when a light beam is irradiated to the converted part. Accordingly, the recording / reproducing areas (data recording / reproducing areas) in the first information layer 302, the second information layer 304, the third information layer 306, and the fourth information layer 308 are not initialized. . As shown in FIG.
- the amount of reflected light from the first information layer 302 and the second information layer 304 is reliably detected, and the focus error signal in the first information layer 302 and the second information layer 304 is detected.
- the level is high. Therefore, it is easy to focus on the position of the second information layer 304 together with the first information layer 302.
- FIG. 5D shows a focus error signal after the first information layer 302, the second information layer 304, and the third information layer 306 are partially initialized.
- the focus error signal shown in FIG. 5D partially includes a region (focus adjustment initialization region) other than a region where data is recorded / reproduced in the first information layer 302, the second information layer 304, and the third information layer 306. It is a focus error signal when the initialization is performed and a light beam is irradiated to the initialized part. Accordingly, the recording / reproducing areas (data recording / reproducing areas) in the first information layer 302, the second information layer 304, the third information layer 306, and the fourth information layer 308 are not initialized. . As shown in FIG.
- the amount of reflected light from the first information layer 302, the second information layer 304, and the third information layer 306 is reliably detected, and the first information layer 302 and the second information layer 306 are detected.
- the level of the focus error signal in the layer 304 and the third information layer 306 is high. Therefore, it is easy to focus on the position of the third information layer 306 together with the first information layer 302 and the second information layer 304.
- the amount of reflected light from the first information layer 302, the second information layer 304, the third information layer 306, and the fourth information layer 308 is reliably detected, and the first information layer 302
- the level of the focus error signal in the layer 302, the second information layer 304, the third information layer 306, and the fourth information layer 308 is high. Therefore, it is easy to focus on the position of the fourth information layer 308 together with the first information layer 302, the second information layer 304, and the third information layer 306.
- the present invention realizes an initialization method and an initialization apparatus for an information recording medium based on the above-described initialization processing experiment result.
- FIG. 1 is a block diagram showing a schematic configuration of the initialization apparatus according to the first embodiment of the present invention.
- FIG. 2 is a diagram showing the configuration of the optical head in the initialization apparatus of the first embodiment.
- an initialization apparatus 1 includes a spindle motor 2 that rotates by mounting a multilayer information recording medium 100 having three or more information layers, an optical head 3 having a plurality of light sources, A transfer table 4 on which the optical head 3 is installed, a moving means 5 for moving the transfer table 4 to a predetermined position, a drive unit 6 for driving a plurality of light sources in the optical head 3, and a light beam of the optical head 3
- a focus position control unit 7 that controls the focus
- an optical controller 8 that controls the drive unit 6 and the focus position control unit 7 are configured.
- the drive unit 6 drives the first light source 10 (see FIG. 2) in the optical head 3 and the second drive circuit 6A in the optical head 3 drives the second light source 11 (see FIG. 2).
- Drive circuit 6B, and each drive circuit 6A, 6B is controlled by the optical controller 8.
- the focus position control unit 7 forms a focus error signal from the first light source 10 in the optical head 3 and forms a focus error signal from the second light source 11 in the optical head 3.
- the focus error circuit 27, the switching circuit 28, and the focus position control circuit 29 that adjusts the position of the objective lens in the optical head 3.
- the optical head 3 in the initialization apparatus 1 according to the first embodiment is provided with two light sources 10 and 11.
- the first light source 10 in the optical head 3 a semiconductor laser having a large spot size and a high output is used in order to perform initialization of a large area in a multilayer information recording medium.
- a semiconductor laser that emits a light beam in the range of 850 nm is used.
- a semiconductor laser having a wavelength of 810 nm is used.
- the second light source 11 in the optical head 3 a semiconductor laser that emits a light beam having a wavelength corresponding to a wavelength at which information is recorded / reproduced on / from the multilayer information recording medium 100 is used.
- the second light source 11 for example, in the case where the wavelength for recording / reproducing the multilayer information recording medium 100 is a light beam having a wavelength of 405 nm, the second light source 11 is output from each information layer (recording film) after initialization of the multilayer information recording medium 100.
- a light beam having a wavelength in the range of 345 nm to 465 nm is preferable, in which the reflectance exhibits a value sufficient for focus adjustment. That is, a preferred wavelength for the second light source 11 is 405 ⁇ 60 nm.
- the multilayer information recording medium is set to perform recording / reproduction using a light beam having a wavelength of 405 nm. Therefore, the focus adjustment can be reliably performed by irradiating the multilayer information recording medium with a light beam having a wavelength of at least 405 ⁇ 60 nm.
- Current voltage control is performed on the first light source 10 in the optical head 3 by the first drive circuit 6 ⁇ / b> A of the drive unit 6.
- the second light source 11 is subjected to current / voltage control by the second drive circuit 6 ⁇ / b> B of the drive unit 6.
- the wavelength selective mirror 18 reflects the first light beam A emitted from the first light source 10 and the second light beam B emitted from the second light source 11. Transparent.
- the second light beam B emitted from the second light source 11 passes through the collimator lens 13, the beam splitter 15, and the quarter wavelength plate 16, passes through the wavelength selective mirror 18, and passes through the objective lens 20 to obtain multilayer information.
- the light is condensed on a predetermined information layer (recording film) of the recording medium 100.
- the second light beam B reflected on the information layer again passes through the objective lens 20, passes through the wavelength selective mirror 18, passes through the quarter-wave plate 16, and is reflected by the beam splitter 15, so that the second light beam B is reflected.
- the light enters the focus error detector 23.
- the reflected light of the second light beam B incident on the second focus error detector 23 is converted into a focus error signal by the second focus error circuit 27.
- the focus error signal is input to the focus position control circuit 29 via the switching circuit 28.
- the focus position control circuit 29 controls the voice coil 19 by forming a control signal based on the input focus error signal.
- the voice coil 19 is driven by the control signal from the focus position control circuit 29, the position of the objective lens 20 is adjusted, and the focus of the second light beam B is the recording film of the designated information layer in the multilayer information recording medium 100 Can be adjusted to the position of
- the first light beam A emitted from the first light source 10 passes through the optical path correction unit 21 made of a liquid crystal element, the collimator lens 12, the beam splitter 14, and the quarter wavelength plate 17, and the wavelength selective mirror 18. Reflected by.
- the first light beam A reflected by the wavelength selective mirror 18 is condensed on a predetermined information layer (recording film) of the information recording medium 100 through the objective lens 20, and the information layer is initialized.
- the first light beam A reflected from the information layer again passes through the objective lens 20, is reflected by the wavelength selective mirror 18, passes through the quarter wavelength plate 17, and is reflected by the beam splitter 14. Then, the light is incident on the first focus error detector 22. The reflected light of the first light beam A incident on the first focus error detector 22 is converted into a focus error signal by the first focus error circuit 26.
- the focus error signal from the first focus error circuit 26 is input to the focus position control circuit 29 (during initialization processing)
- the focus error The signal is input to the focus position control circuit 29 via the switching circuit 28.
- the optical path can be corrected by the optical path correction unit 21.
- the switching circuit 28 inputs either the focus error signal from the first focus error circuit 26 or the focus error signal from the second focus error circuit 27 to the focus position control circuit 29.
- the optical controller 8 controls the switching.
- the optical controller 8 performs drive control of the spindle motor 2, the moving means 5, the drive unit 6, the focus position control unit 7, and the like.
- the optical controller 8 controls the drive of the spindle motor 2, controls the intensity setting of the first light beam A and the second light beam B, and applies the first light beam A to the information recording medium 100 in the thickness direction.
- the control is performed for the entire initialization operation such as drive control for partial initialization for reciprocating relative movement (up and down movement) and switching control of the switching circuit 28.
- the focus position control circuit 29 operates the voice coil 19 to control the focus position of the objective lens 20 to the position of the recording film of the specific information layer.
- focus adjustment of the objective lens 20 is performed based on the focus error signal by the second light beam B. .
- focus adjustment by the second light beam B is basically performed as needed.
- a focus error signal by the first light beam A is displayed. Based on this, the focus of the objective lens 20 may be adjusted.
- the switching control is performed by the switching circuit 28 and the focus adjustment is performed by the second light beam B. Thereafter, an initialization process using the first light beam A may be performed.
- the numerical aperture NA of the objective lens 20 is appropriately designed according to the optical characteristics of the recording film of the information layer, the thickness of the substrate, etc. in the multilayer information recording medium 100 to be initialized.
- the transparent separation layer formed between the information layers is 30 ⁇ m or less, and a higher numerical aperture NA is advantageous in order to improve the separation of the focus error signal.
- NA ⁇ 0.6 is preferable.
- the focus adjustment can be performed by a general adjustment method such as a knife edge method or an astigmatism method.
- a first light beam A having a large power is irradiated from the objective lens 20 to a predetermined recording film of the multilayer information recording medium 100.
- the spot shape of the first light beam A at the focus position is set to be an oval having a length of 30 to 200 ⁇ m in the radial direction and 1 to 5 ⁇ m in the circumferential direction of the multilayer information recording medium 100. Therefore, it is possible to initialize a wide range with respect to the information layer of the multilayer information recording medium 100 by the first light beam A.
- amends the optical path of the 1st light beam A from the 1st light source 10 demonstrated with the example comprised by the liquid crystal element
- the installation place of the optical path correction unit 21 may be between the collimator lens 12 and the beam splitter 14.
- FIG. 3 shows the position where the light spots of the first light beam A and the second light beam B are irradiated on the multilayer information recording medium 100, the spot size, and the initialization of the recording film of the information layer in the multilayer information recording medium 100. It is the elements on larger scale which show a completed area and an uninitialized area notionally.
- the cross hatch portion is an initialized region 112 initialized by the first light beam A, and the white portion indicates an uninitialized region 113.
- the focus positions in the film thickness direction of the information layer of the first light beam A and the second light beam B are the same (the displacement amount is 50 nm at the maximum). Further, as shown in FIG. 3, the focus position in the information layer surface is such that the beam spot 111 of the second light beam B is more than the beam spot 110 of the first light beam A with respect to the initialization progress direction in the track direction. It is set to be backward. Further, as shown in FIG. 3, the spot size of the second light beam B is set smaller than the spot size of the first light beam A. Thereby, the focus adjustment in the initialization apparatus of the first embodiment can be performed based on the focus error signal from the second light beam B in the region where the partial initialization has been completed by the first light beam A.
- FIG. 4 is a cross-sectional view showing a cross-sectional configuration of the multilayer information recording medium 100 that is initialized by the initialization apparatus 1 of the first embodiment.
- the multilayer information recording medium 100 includes N layers from a first information layer 502 to an Nth information layer 507 (where N is a positive integer of 3 or more) formed on a substrate 501.
- the information layers are formed, and transparent separation layers 503, 504, and 506 are formed between the information layers.
- a cover layer 508 is formed on the last Nth information layer 507 (on the lower side in FIG. 4).
- the nth information layer 505 (where n is an integer and 2 ⁇ n ⁇ N) explain.
- a reflective film 510, a second dielectric film 511, an interface film 512, a recording film 513, an interface film 512, and a first dielectric film 514 are stacked in this order on a substrate 501. Is formed.
- the n-th information layer 505 which is an intermediate information layer includes a transmittance adjusting film 515, a reflective film 510, a second dielectric film 511, an interface film 512, a recording film 513, an interface film 512, and a first film in order from the substrate 501 side.
- One dielectric film 514 is laminated.
- the Nth information layer 507 which is the final information layer farthest from the substrate 501, has a transmittance adjusting film 515, a reflective film 510, a second information layer 505 in order from the substrate 501, similarly to the nth information layer 505.
- a dielectric film 511, an interface film 512, a recording film 513, an interface film 512, and a first dielectric film 514 are laminated.
- the first information layer 502, the nth information layer 505, and the Nth information layer 507 are described using an example in which an interface film 512 is provided, but depending on the specifications of the multilayer information recording medium, Even if the first dielectric 514 or the second dielectric 511 is in direct contact with the recording film 513, it may not be provided if the recording / reproducing performance and the weather resistance are not deteriorated.
- the substrate 501 in the multilayer information recording medium 100 is a disk-shaped transparent substrate, and as the material of the substrate 501, for example, a resin such as polycarbonate, amorphous polyolefin, or polymethyl methacrylate (PMMA), or glass is used. it can.
- a guide groove (track pitch 0.32 ⁇ m) for guiding a light beam which is a laser beam may be formed on the surface on the first information layer side as necessary.
- a substrate having a thickness of 500 ⁇ m to 1300 ⁇ m is used as the substrate 501.
- the transparent separation layers 503, 504, and 506 in the multilayer information recording medium 100 shown in FIG. 4 are formed using a resin such as a photocurable resin (particularly preferably an ultraviolet curable resin) or a slow-acting thermosetting resin, for example.
- a resin such as a photocurable resin (particularly preferably an ultraviolet curable resin) or a slow-acting thermosetting resin, for example.
- the transparent separation layers 503, 504, and 506 are formed by applying the above resin on each information layer to form a spin coat, and then curing the resin.
- a transfer substrate (mold) having grooves of a predetermined shape formed on the surface is placed on a resin before curing, and then the substrate 501 is formed. , The transfer substrate and the resin are brought into close contact with each other to cure the resin.
- the transparent separation layers 503, 504, and 506 in which predetermined guide grooves are formed can be formed by peeling the transfer substrate from the cured resin.
- the cover layer 508 is formed using, for example, a resin such as a photocurable resin (particularly, an ultraviolet curable resin is preferable), a slow-acting thermosetting resin, or a dielectric, as a material for the cover layer 508. It is preferable that there is little light absorption with respect to the laser beam to be used.
- a resin such as polycarbonate, amorphous polyolefin, or polymethyl methacrylate (PMMA), or glass may be used.
- cover layer 508 when a resin such as polycarbonate, amorphous polyolefin, polymethyl methacrylate (PMMA), or glass is used as the cover layer 508, for example, a photo-curing resin (particularly, an ultraviolet-curing resin is preferable) or a slow-acting property.
- the cover layer 508 is formed by bonding the first dielectric film in contact with the Nth information layer with a resin such as a thermosetting resin.
- the thickness of the reflective film 510 is more preferably in the range of 3 nm to 250 nm.
- the thickness of the reflective film 510 is less than 3 nm, the cooling capacity is insufficient and the signal amplitude decreases greatly, which is not preferable.
- the cooling capacity does not change, but there is a problem that the manufacturing time and material cost increase and the manufacturing cost becomes high.
- the second dielectric film 511 formed on the reflective film 510 includes, for example, an oxide such as SiO 2 , ZrO 2 , Cr 2 O 3 , In 2 O 3 , TiO 2 , or the like.
- a material such as a composite oxide, nitride, or ZnS—SiO 2 is used. More preferably, a material having a small light absorption with an extinction coefficient of 0.15 or less with respect to a wavelength of 405 nm is used.
- the thickness of the second dielectric film 511 is preferably 3 nm to 50 nm. The reason is that when the thickness of the second dielectric film 511 is less than 3 nm, the signal amplitude decreases greatly, and when it is thicker than 50 nm, the transmittance decreases due to absorption of the film.
- the interface film 512 in each information layer for example, an oxide such as SiO 2 , ZrO 2 , Cr 2 O 3 , In 2 O 3 , or TiO 2 , or a composite oxide or nitride thereof is used. More preferably, a material having a small light absorption with an extinction coefficient of 0.15 or less with respect to a wavelength of 405 nm is used.
- the thickness of the interface film 512 is preferably 2 nm to 10 nm. The reason for this is that when the film thickness of the interface film 512 is thinner than 2 nm, the effect of suppressing element diffusion into the recording film is reduced, and the adhesion is lowered. On the other hand, when it is thicker than 10 nm, the transmittance decrease due to the absorption of the film becomes large.
- a phase change material made of GeSbTe or GeBiTe is used for the recording film 513 in each information layer.
- a phase change material formed of an alloy of GeTe—Sb 2 Te 3 and GeTe—Bi 2 Te 3 is more preferable because it has a large amount of optical change and high-speed phase change is performed.
- the film thickness of the recording film 513 is preferably 2 nm to 30 nm. The reason is that when the film thickness of the recording film 513 is thinner than 2 nm, the rewriting (erasing) performance is lowered, and the signal amplitude is greatly lowered. On the other hand, when it is thicker than 30 nm, the signal amplitude is lowered, and the signal preservation property (archival performance) is lowered.
- the transmittance adjustment film 515 in the nth information layer 505 and the Nth information layer 507 which are intermediate information layers has a function of adjusting the transmittance of the nth information layer.
- the transmittance adjustment film 515 By forming the transmittance adjustment film 515, and the transmittance T c (%) of the information layer recording film 513 is in a crystalline state, the recording film 513 is the transmittance T a of the information layer in the amorphous state (% ) Can be raised together.
- the transmittance adjusting film 515 also has a function of quickly diffusing heat generated in the recording film 513 to the reflective film 510 and cooling the recording film 513.
- the refractive index n1 and the attenuation coefficient k1 of the transmittance adjusting film 515 preferably satisfy n1 ⁇ 2.0 and k1 ⁇ 0.1. More preferably, the refractive index n1 and the attenuation coefficient k1 of the transmittance adjusting film 515 satisfy 2.0 ⁇ n1 ⁇ 3.0 and k1 ⁇ 0.08. Thus, by setting the refractive index n1 and the attenuation coefficient k1 in the transmittance adjusting film 515, the transmittance adjusting film 515 having a high transmittance can be formed, and a preferable intermediate information layer is obtained.
- the reflectance of each information layer with respect to laser light having a wavelength of 405 nm is at an equivalent level.
- the reflectance of the information layer that maximizes the reflectance is R max
- the reflectance of the information layer that minimizes the reflectance is R min , (R max ⁇ R min ). Satisfies / R max ⁇ 0.5.
- the reflectance with respect to the laser beam having a wavelength of 405 nm from the surface of the cover layer 508 is about 4%.
- the initialization target is the multilayer information recording medium 100 having three or more information layers shown in FIG.
- FIG. 6 is a flowchart showing a large flow in the initialization method of the first embodiment.
- step S1 the initialization device is activated and initialization is started. Specifically, the multilayer information recording medium 100 to be initialized is mounted on the information recording medium mounting portion provided with the spindle motor 2 and rotates.
- step S2 an initialization process is performed on the information layer farthest from the light beam incident surface on which the light beam is incident, that is, the recording film of the first information layer 502 in the multilayer information recording medium 100. .
- the initialization process for the recording film of the first information layer 502 When the initialization process for the recording film of the first information layer 502 is completed, the initialization process for the recording film of the next second information layer is performed. When the initialization process for the recording film of the second information layer is completed, the initialization process for the recording film of the information layer in the direction of the cover layer 508 which is the next information layer is performed. In this way, the initialization process is sequentially performed on the recording film of each information layer from the substrate 501 side toward the cover layer 508. In the flowchart shown in FIG. 6, the initialization process for the nth information layer 505, which is an intermediate information layer, is performed as step S (n + 1), and the information closest to the cover layer 508 is obtained as step S (N + 1).
- step S (N + 1) when the initialization process for the recording film of the Nth information layer 507 closest to the light beam incident surface in the multilayer information recording medium 100 is completed, the initialization process for all information layers is completed, and the spindle The rotation of the motor 2 is stopped and the initialization for the multilayer information recording medium 100 is completed (step S (Final)).
- the initialization process for the first information layer 502 in step S2 shown in FIG. 6 performs focus adjustment using the first light beam A which is an initialization light beam.
- the initialization process is performed based on the adjustment result. This is because the first information layer 502 is set to increase the amount of reflected light from the first information layer 502 because it is not necessary to reduce the transmittance.
- FIG. 7 is a follow chart showing detailed steps of the initialization process of the nth information layer 505 in step S (n + 1) shown in FIG.
- step S101 initialization for initialization processing of the n-th information layer 505 is performed.
- the transfer table 4 is moved to the initialization start position, and the space between the surface of the cover layer 508 (light beam incident surface) of the multilayer information recording medium 100 and the objective lens 20 (see FIG. 2) is set in advance. Adjust to the predetermined distance.
- step S102 the first light source 10 and the second light source 11 are caused to emit light with a preset power.
- step S103 partial initialization is performed using the first light beam A from the first light source 10.
- This partial initialization initializes (crystallizes) a part of the recording film in an area not used for recording and reproduction (initialization area for focus adjustment, for example, the innermost area of the disc) in the multilayer information recording medium 100.
- the focus position of the first light beam A sufficient for initialization (crystallization) is reciprocated relative to the multilayer information recording medium 100 in the thickness direction (vertical direction). .
- the first light source 10 is driven by the first drive circuit 6A based on a control signal from the optical controller 8. As described above, by shifting the focus position of the first light beam A having sufficient power for initialization in the thickness direction (vertical direction), the recording films of the other information layers including the recording film of the nth information layer A part of is initialized.
- the amplitude (vertical movement distance) of the first light beam A is the first information so that a part of the recording film of the n-th information layer 505 is reliably initialized. It is set so that a part of all the recording films from the layer 501 to the Nth information layer 507 is initialized. In this way, by initializing a part of the recording film of the n-th information layer 505, the second information beam 505 (wavelength: 405 nm) for focus adjustment is used for the n-th information layer 505. The amount of reflected light from the recording film increases, and a focus error signal having a sufficiently large level is detected in the nth information layer 505.
- the number of reciprocating operations (vertical operations) in the thickness direction of the focus position of the first light beam A in the partial initialization is counted by the optical controller 8, and the partial initialization is controlled by the count number.
- the direction from the light beam incident surface, which is the surface of the cover layer 508, to the substrate 501 side (hereinafter referred to as the upward direction) and the light beam incident surface from the opposite substrate 501 side.
- the power of the first light beam A is changed in the direction toward (hereinafter referred to as the downward direction). For example, it is more preferable that the power when moving downward is higher than the power when moving upward. This is because the information layer close to the cover layer 508 is initialized before the information layer close to the substrate 501 when the power when moving from the cover layer 508 side, which is the upper direction, to the substrate 501 side is high. is there.
- the information layer on the near side near the cover layer 508 is initialized before the information layer on the back side near the substrate 501, the information layer is initialized with respect to the wavelength of the first light beam A. This is because the transmittance of the information layer on the near side is greatly reduced, and energy cannot enter the information layer close to the substrate 501 on the far side, making partial initialization difficult.
- step S104 the focus error signal from the second focus error circuit 27 is input to the focus position control circuit 29 via the switching circuit 28.
- the focus position control circuit 29 drives and controls the voice coil 19 based on the focus error signal from the focus error detector 23 to adjust the position of the objective lens 20, and focuses the second light beam B on the nth.
- the recording layer 513 of the information layer 505 is aligned with the position.
- step S105 it is confirmed whether the second light beam B is out of focus with respect to the recording film 513 of the nth information layer 505 based on the focus error signal at that time. If it is out of focus, the process proceeds to step S106.
- step S106 if the defocus is within a predetermined number of times (for example, 5 times), the steps after the partial initialization in step S103 are performed again. On the other hand, if it is detected in step S106 that the defocus has exceeded a predetermined number of times (for example, 5 times), it is determined that there is an abnormality in the multilayer information recording medium 100, and the process proceeds to step S111. The first light beam A and the second light beam B are extinguished to forcibly end the initialization processing operation.
- a predetermined number of times for example, 5 times
- step S105 If no out-of-focus has occurred in step S105, the first light beam A is set to a power suitable for initialization in step S107.
- step S108 the movement of the transfer table 4 is started. Note that the order of the power setting of the first light beam A and the start of movement of the transfer table 4 in steps S107 and S108 may be reversed. Further, steps from step S101 to step S108 must be performed outside the data recording / reproducing area of the multilayer information recording medium 100.
- step S109 the transfer table 4 is driven to move in the radial direction of the multilayer information recording medium 100 at a predetermined feed speed.
- the multi-layer information recording medium 100 is irradiated with the first light beam A set to a predetermined power while the transfer table 4 moves in the radial direction of the rotating multi-layer information recording medium 100.
- initialization of the recording film of the nth information layer 505 is performed.
- step S110 it is determined in step S110 whether or not the transfer table 4 has reached the initialization end position. If the transfer table 4 has not reached the initialization end position, the process returns to step S104, the focus adjustment by the second light beam B is performed, and the recording of the nth information layer 505 is performed based on the focus error signal at that time. Whether the second light beam B is out of focus with respect to the film 513 is confirmed. Then, the steps from Step S106 to Step S110 are repeated.
- step S110 If it is determined in step S110 that the transfer table 4 has reached the initialization end position, the first light beam A and the second light beam B are extinguished in step S111 and the nth information layer 505 is extinguished. This completes the initialization process for the recording film.
- the flowchart shown in FIG. 7 is the initialization process for the recording film 513 of the nth information layer 505, but the initialization process for the recording film 513 of the Nth information layer 507 closest to the light beam incident surface is also performed. In the initialization method of the first embodiment, the same processing is performed.
- the focus adjustment in the subsequent steps may be performed to perform the initialization process on the information layer.
- the initialization process of the recording film 513 of the first information layer 502 is an example in which focus adjustment is performed using the first light beam A for initialization.
- the initialization process for the recording film of the first information layer 502 may be another initialization method. That is, the initialization method performed on the recording film of the nth information layer 505 shown in FIG. 7 may be performed on the first information layer 502.
- the recording film initialization process of the Nth information layer 507 is performed by applying the second light beam B for focus adjustment after partial initialization as shown in FIG.
- the focus adjustment is performed and the entire initialization process is performed by the first light beam A based on the adjustment result.
- the initialization process for the recording film of the Nth information layer 507 is performed in the first process.
- the focus adjustment may be performed using the light beam A
- the initialization process may be performed using the first light beam A based on the adjustment result. This is because the recording film of the Nth information layer 507 closest to the light beam incident surface is caused by the first light beam A as shown in the focus error signal of the fourth information layer 308 in FIG. 11E described above. This is because the level of the focus error signal is high and the recording film 513 of the Nth information layer 507 can be focused.
- the focus adjustment can be performed with high accuracy on the recording film of each information layer in the multilayer information recording medium.
- a reliable initialization process can be performed on each recording film.
- Embodiment 2 The initialization method and initialization apparatus according to the second embodiment of the present invention will be described below. Note that the second embodiment is different from the first embodiment in the initialization method. Since the initialization apparatus of the second embodiment has substantially the same configuration as that of the initialization apparatus of the first embodiment, the second embodiment shows the same functions and configurations as those of the first embodiment. The same reference numerals are given, and the description of Embodiment 1 is applied to the description.
- the first information layer 502 on the substrate side to the Nth information layer 507 on the cover layer side is sequentially performed on each of the recording films.
- the flowchart shown in FIG. 8 is a flowchart showing detailed steps of the initialization process of the nth information layer 505 in step S (n + 1) shown in FIG. That is, the initialization process in the n-th information layer 505, which is an intermediate information layer, is all executed by the same steps in the initialization method of the second embodiment.
- step S201 initialization for initialization processing of the nth information layer 505 is performed. Specifically, the transfer table 4 is moved to the initialization start position, and the space between the surface of the cover layer 508 (light beam incident surface) of the multilayer information recording medium 100 and the objective lens 20 (see FIG. 2) is set in advance. Adjust to the predetermined distance.
- step S202 the first light source 10 and the second light source 11 are caused to emit light with a preset power.
- step S203 partial initialization is performed using the first light beam A from the first light source 10.
- This partial initialization initializes (crystallizes) a part of the recording film in an area not used for recording and reproduction (initialization area for focus adjustment, for example, the innermost area of the disc) in the multilayer information recording medium 100.
- the focus position of the first light beam A sufficient for initialization (crystallization) is set in the thickness direction (up and down) with respect to the multilayer information recording medium 100. Direction).
- the recording films of the other information layers including the recording film of the nth information layer A part of is initialized.
- the partial initialization in the initialization method of the second embodiment is executed in the same manner as the initialization method of the first embodiment.
- the number of reciprocating operations (vertical operations) in the thickness direction of the focus position of the first light beam A in the partial initialization is counted by the optical controller 8, and depending on the count number Partial initialization is controlled.
- the direction from the light beam incident surface which is the surface of the cover layer 508, to the substrate 501 side (The power of the first light beam A is changed in the upward direction) and the direction from the substrate 501 to the light beam incident surface (downward), and the power when moving downward moves upward. It is set higher than the power when you do.
- step S205 it is confirmed whether the second light beam B is out of focus with respect to the recording film 513 of the nth information layer 505 based on the focus error signal at that time. If it is out of focus, the process proceeds to step S206.
- step S206 if out of focus is within a predetermined number of times (for example, 5 times), the steps after the partial initialization in step S203 are performed again. On the other hand, if it is detected in step S206 that defocusing has exceeded a predetermined number of times (for example, 5 times), it is determined that there is an abnormality in the multilayer information recording medium 100, and the process proceeds to step S207. The first light beam A and the second light beam B are extinguished to forcibly end the initialization processing operation.
- a predetermined number of times for example, 5 times
- step S205 If no out-of-focus has occurred in step S205, the first light beam A is set to a power suitable for initialization in step S208.
- step S209 the movement of the transfer table 4 is started. Note that the order of the power setting of the first light beam A and the start of movement of the transfer table 4 in steps S208 and S209 may be reversed.
- step S210 the focus error signal from the first focus error circuit 26 is input to the focus position control circuit 29 via the switching circuit 28.
- the focus position control circuit 29 fine adjustment of the position with respect to the objective lens 20 is performed according to the focus error signal from the first focus error circuit 26, and the focus of the second light beam B is recorded on the nth information layer 505. Match to the film 513 with high accuracy.
- focus adjustment is further performed by the focus error signal from the first focus error circuit 26. Yes. This is because the chromatic aberration of the light beams collected by the two light beams A and B is compensated to eliminate unevenness in the initialization, and a highly accurate and stable initialization process is performed.
- step S211 whether or not the first light beam A is out of focus with respect to the position of the recording film 513 of the nth information layer 505 is confirmed based on the focus error signal from the first light beam A. To do. If it is out of focus, the process proceeds to step S212.
- step S212 if the defocus is within a predetermined number of times (for example, 5 times), the focus adjustment by the first light beam A in step S210 and the defocus in step S211 are performed again. On the other hand, if it is detected in step S212 that the defocus has exceeded a predetermined number of times (for example, 5 times), it is determined that there is an abnormality in the multilayer information recording medium 100, and the process proceeds to step S207. The first light beam A and the second light beam B are extinguished to forcibly end the initialization processing operation.
- a predetermined number of times for example, 5 times
- the focus adjustment step by the first light beam A in step S210 and the defocus detection step in step S211 may be performed while moving the transfer table 4, or after the transfer table 4 is stopped once. Also good. However, each step from step S201 to step S212 must be performed outside the data area in the multilayer information recording medium 100. Therefore, when an initialization process in step S214 described later is started, it is set to be the starting point of the data area in the recording film 513 of the nth information layer 505 in the multilayer information recording medium 100.
- step S213 the second light beam B is quenched. It should be noted that step S213 can be omitted when there is no possibility that the initialization target multilayer information recording medium 100 is unnecessarily initialized by the second light beam B.
- step S209 the transfer table 4 is driven to move in the radial direction of the multilayer information recording medium 100 at a predetermined feed speed.
- the transfer table 4 moves in the radial direction of the rotating multilayer information recording medium 100 and is arranged at the starting point of the recording film to be initialized, the first light set to a predetermined power is set.
- the recording film of the nth information layer 505 is initialized (step 214).
- the movement start step of the transfer table 4 in step 209 may be performed after the extinction step of the second light beam B in step S213 and before the initialization process in step S214.
- step S215 it is determined whether or not the transfer table 4 has reached the initialization end position. If the transfer table 4 has not reached the initialization end position, the process returns to step S210, and focus adjustment is performed based on the focus error signal from the first light beam A. In step S211, it is confirmed whether or not an out-of-focus condition occurs with respect to the recording film of the nth information layer 505. Then, the initialization process is performed again. At this time, since the second light beam B is extinguished, step S213 is naturally not executed.
- step S215 If it is determined in step S215 that the transfer table 4 has reached the initialization end position, the first light beam A is extinguished in step S216, and the nth information layer 505 is initialized with respect to the recording film 513. The process ends.
- the flowchart shown in FIG. 8 is an initialization process for the recording film of the nth information layer 505, but the initialization process for the recording film of the Nth information layer 507 closest to the light beam incident surface is also described in the embodiment. In the initialization method 2, the same processing is performed.
- the focus adjustment in the subsequent steps may be performed to perform the initialization process on the information layer.
- the initialization process of the recording film of the first information layer 502 may be performed by adjusting the focus using the first light beam A for initialization.
- the initialization method performed on the recording film of the nth information layer 505 shown in FIG. 8 may be similarly performed on the first information layer 502.
- the initialization process of the recording film of the Nth information layer 507 may be the initialization method shown in FIG. 8, or focus adjustment is performed by the first light beam A.
- the initialization process may be performed by the first light beam A based on the adjustment result.
- the recording film of the Nth information layer 507 close to the light beam incident surface as shown in the fourth information layer 308 in FIG. 11E described above, in the focus error signal by the first light beam A. This is because the level is high and the recording film 513 of the Nth information layer 507 can be focused.
- the initialization method and initialization apparatus As described above, in the initialization method and initialization apparatus according to the second embodiment of the present invention, it is possible to reliably perform focus adjustment on a multilayer information recording medium having a plurality of information layers. It is possible to perform initialization without any problems. In addition, the initialization method and the initialization apparatus according to the second embodiment perform the focus adjustment on the recording film of the information layer that performs the initialization even in the first light beam A that performs the initialization. It is possible to form initialization without unevenness.
- the information recording medium initialization method and initialization apparatus of the present invention all of the multilayer information recording media having three or more information layers are used.
- the information layer can be initialized stably and reliably.
- a phase change material composed of GeBiTe is applied to the recording film of each information layer of the multilayer information recording medium to be initialized so that the reflectance from each information layer after initialization is 3 to 4%. Designed.
- the wavelength of the first light beam A is 810 nm
- the wavelength of the second light beam B is 405 nm.
- the optical mechanism was designed so that the spot shape had a length of 96 ⁇ m in the radial direction of the multilayer information recording medium and an elliptical length of 1 ⁇ m in the circumferential direction.
- the spot shape of the second light beam B is a circle having a diameter of 1 ⁇ m.
- the partial initialization by the first light beam A in Step S103 shown in FIG. 7 was performed on the recording films in all the information layers. That is, partial initialization of all recording films was performed by reciprocating the focus position of the first light beam A a large number of times in the thickness direction (vertical direction) of the multilayer information recording medium.
- the initialization process for the recording film of the second information layer was executed.
- the partial initialization in step S103 shown in FIG. 7 was performed on the recording films of all information layers.
- the linear velocity with respect to the multilayer information recording medium during the initialization process was 8 m / s
- the feed rate of the transfer table 4 was 20 ⁇ m
- the power of the first light source 10 was 1500 mW.
- the initialization process for the recording film of the third information layer was finally performed.
- focus adjustment is performed using the first light beam A and initialization is performed using the first light beam A without performing the partial initialization in step S103 illustrated in FIG. It was.
- the linear velocity with respect to the multilayer information recording medium was 8 m / s
- the feed rate of the transfer table 4 was 20 ⁇ m
- the power of the first light source 10 was 1000 mW.
- the initialization method of the first embodiment shown in FIG. 7 is executed for the intermediate information layer (second information layer).
- the recording films in all the information layers could be initialized stably and without unevenness.
- the phase change material composed of GeBiTe is applied to the recording film of each information layer in the same manner as the multilayer information recording medium in Example 1 described above.
- the reflectivity from each information layer after initialization was designed to be 3 to 4%.
- the specifications of the two light beams used in the initialization method of the second embodiment are the same as those of the first light beam A and the second light beam B of the first embodiment.
- the initialization device used in Example 1 and Example 2 is the initialization device described in the first embodiment.
- the initialization method of Example 2 for a multilayer information recording medium having four information layers was executed using the initialization method of Embodiment 2 shown in the flowchart of FIG. First, initialization processing of the first information layer on the substrate side was performed. In the initialization process for the first information layer, the focus adjustment is performed by the first light beam A without performing the partial initialization in step S203 shown in FIG. 8, and the initialization is performed by the first light beam A. went. During the initialization process, the linear velocity with respect to the multilayer information recording medium was 8 m / s, the feed rate of the transfer table 4 was 20 ⁇ m, and the power of the first light source 10 was 3800 mW.
- the initialization process for the recording film of the second information layer was executed.
- the partial initialization in step S203 shown in FIG. 8 was performed on the recording films of all the information layers.
- the linear velocity with respect to the multilayer information recording medium during the initialization process was 8 m / s
- the feed rate of the transfer table 4 was 20 ⁇ m
- the power of the first light source 10 was 2600 mW.
- the initialization process for the recording film of the third information layer was executed.
- the partial initialization in step S203 shown in FIG. 8 was performed on the recording films of all information layers.
- the linear velocity with respect to the multilayer information recording medium at the time of this initialization process was 8 m / s
- the feed rate of the transfer table 4 was 20 ⁇ m
- the power of the first light source 10 was 1400 mW.
- the initialization process for the fourth information layer recording film was finally performed.
- the focus adjustment was performed by the first light beam A without performing the partial initialization in step S203 shown in FIG.
- the linear velocity with respect to the multilayer information recording medium was 8 m / s
- the feed rate of the transfer table 4 was 20 ⁇ m
- the power of the first light source 10 was 1000 mW.
- the multilayer information recording medium having four information layers, by executing the initialization method of the intermediate information layer (second information layer and third information layer) and the second embodiment, The recording films in all the information layers could be initialized stably and without unevenness.
- the information recording medium initialization method and initialization apparatus of the present invention have been described with specific examples in the above-described embodiments, but the present invention is not limited to the steps and configurations described in the above-described embodiments. The same steps and configurations based on the technical idea of the present invention are also included in the present invention.
- the present invention provides an initialization method and an initialization apparatus that can reliably initialize an information recording medium having a recording film that records and reproduces information by irradiation with a laser beam or the like. It has an excellent effect in the field of recording medium initialization and is useful.
- the present invention can be applied to initialization of multi-layer information recording media such as large-capacity "Blu-ray Discs", small-diameter and large-capacity disks such as 6 cm and 8 cm in diameter, and next-generation SIL. Since it can be applied to initialization of a (Solid Immersion Lens) type near-field optical multi-layer disc, it is highly versatile.
Landscapes
- Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Optical Recording Or Reproduction (AREA)
- Manufacturing Optical Record Carriers (AREA)
- Optical Record Carriers And Manufacture Thereof (AREA)
- Optical Head (AREA)
Abstract
Description
図10に示す多層情報記録媒体300を用いて初期化処理を行うために、本発明者は810nmの波長の光ビームを出射する光学機器である光学ヘッドを用いた。
なお、以下に第2の情報層304や第3の情報層306の初期化を行っているが、これらは実験的にそれぞれの情報層を形成した直後に初期化を行っている。
図11Eは、全ての情報層302,304,306,308が初期化された状態における、波長810nmの光ビームを照射したときのフォーカスエラー信号を示す。
上記のような実験結果は、他の波長、例えば波長680nmの光ビーム(赤色)を用いても行ったが、同様の結果を得た。
前記情報層が有する記録膜に対して、初期化用の波長を有する第1の光ビームにより前記記録膜の一部の領域を部分初期化するステップ、
前記情報記録媒体において情報を記録再生するための波長に対応した波長を有する第2の光ビームにより、前記記録膜における部分初期化された領域を照射するステップ、
前記第2の光ビームの照射により生じる前記情報層からの反射光により生成されたフォーカスエラー信号に基づいて、フォーカス位置を調整するステップ、
フォーカス位置が調整された前記第1の光ビームを前記情報記録媒体に照射することにより前記記録膜の初期化を行っている。このようなステップを有する初期化方法によれば、多層情報記録媒体の全ての情報層の記録膜を安定して、且つ確実に初期化することができる。
前記第2の光ビームにより前記情報記録媒体を照射するステップにおいて、部分的に初期化された前記フォーカス調整用初期化領域に対して前記第2の光ビームを照射してもよい。
少なくとも第nの情報層における前記記録膜に対して、前記第1の光ビームにより前記記録膜の一部の領域を部分初期化するステップにおいて、
前記第1の光ビームは、前記記録膜における記録再生領域以外のフォーカス調整用初期化領域を部分的に初期化し、
前記第2の光ビームにより前記情報記録媒体を照射するステップにおいて、部分的に初期化された前記フォーカス調整用初期化領域に対して前記第2の光ビームを照射してもよい。
前記第1の光ビームは、前記記録膜における記録再生領域以外のフォーカス調整用初期化領域を部分的に初期化し、
前記第2の光ビームにより前記情報記録媒体を照射するステップにおいて、部分的に初期化された前記フォーカス調整用初期化領域に対して前記第2の光ビームを照射してもよい。
前記記録膜からの反射光をもとに生成されるフォーカスエラー信号に基づいてフォーカス位置の制御を、前記第2の光ビームを用いて行った後、前記第1の光ビームに切り替えて再度行ってもよい。
前記情報層が有する記録膜における記録再生領域以外の領域にフォーカス調整用初期化領域が形成されており、
前記フォーカス調整用初期化領域が初期化用の波長を有する第1の光ビームにより部分的に初期化されて、前記情報記録媒体において情報を記録再生するための波長に対応した波長を有する第2の光ビームにより前記フォーカス調整用初期化領域が照射されて、前記情報層からの反射光により生成されたフォーカスエラー信号に基づいて、フォーカス位置を調整することにより、フォーカス位置が調整された前記第1の光ビームにより前記記録膜の初期化を行って製造されている。このように構成された情報記録媒体は、全ての情報層の記録膜が確実に初期化されており、信頼性の高い記録媒体を提供することができる。
前記初期化装置は、前記記録膜に光ビームを照射する少なくとも1つの光学ヘッドを備え、
前記光学ヘッドは、初期化用の波長を有する第1の光ビームを出射する第1の光源、前記情報記録媒体において情報を記録再生するための波長に対応した波長を有する第2の光ビームを出射する第2の光源、前記第1の光ビームと前記第2の光ビームを前記記録膜に集光させる対物レンズ、および少なくとも一つの光ビームのフォーカス位置制御を行うフォーカス位置制御部、を具備する。このように構成された初期化装置によれば、多層情報記録媒体の全ての情報層の記録膜を安定して、且つ確実に初期化することができる。
先ず始めに、本発明の情報記録媒体の初期化方法を着想した、初期化処理実験結果について説明する。
本発明は、上記の初期化処理実験結果に基づいて、情報記録媒体のための初期化方法および初期化装置を実現したものである。
以下、本発明に係る実施の形態1の情報記録媒体の初期化方法および初期化装置について説明する。
図1は、本発明に係る実施の形態1の初期化装置の概略構成を示すブロック図である。図2は実施の形態1の初期化装置における光学ヘッドの構成を示す図である。
図1において、実施の形態1の初期化装置1は、3層以上の情報層を有する多層情報記録媒体100を装着して回転駆動するスピンドルモータ2と、複数の光源を有する光学ヘッド3と、光学ヘッド3を設置した移送台4と、移送台4を所定の位置に移動させる移動手段5と、光学ヘッド3における複数の光源を駆動するための駆動部6と、光学ヘッド3の光ビームのフォーカスを制御するフォーカス位置制御部7と、駆動部6およびフォーカス位置制御部7を制御する光学コントローラ8とを有して構成されている。
次に、光学ヘッド3の詳細構造について説明する。図2に示すように、実施の形態1の初期化装置1における光学ヘッド3には、2つの光源10,11が設けられている。
光学ヘッド3における第1の光源10としては、多層情報記録媒体における大面積の初期化を実行するために、スポットサイズが大きく、高出力の半導体レーザが用いられており、例えば、波長が630~850nmの範囲内の光ビームを出射する半導体レーザが用いられている。実施の形態1の初期化装置1においては、810nmの波長の半導体レーザが用いられている。また、光学ヘッド3における第2の光源11としては、多層情報記録媒体100に対して情報の記録再生を行う波長に対応した波長の光ビームを出射する半導体レーザが用いられている。第2の光源11としては、例えば、多層情報記録媒体100の記録再生を行う波長が405nmの光ビームである場合、当該多層情報記録媒体100の初期化後の各情報層(記録膜)からの反射率がフォーカス調整するのに十分な値を示す、345nm~465nmの範囲内の波長を持つ光ビームが好ましい。即ち、第2の光源11として好ましい波長は、405±60nmである。より好ましくは、405±20nmの波長の光ビームであり、この光ビームを用いることにより、各情報層(記録膜)からのフォーカスエラー信号は確実に現れるため、各情報層の記録膜に対するフォーカス調整を確実に、且つ高精度に行うことが可能となる。当該多層情報記録媒体においては、405nmの波長の光ビームを用いて記録再生が行われるように設定されているためである。したがって、少なくとも405±60nmの波長の光ビームを当該多層情報記録媒体に照射することにより確実にフォーカス調整を行うことが可能となる。
光学ヘッド3における第1の光源10に対しては、駆動部6の第1の駆動回路6Aにより電流電圧制御が行われる。また、第2の光源11に対しては、駆動部6の第2の駆動回路6Bにより電流電圧制御が行われる。
第1の光ビームAのフォーカス位置におけるスポット形状は、多層情報記録媒体100の径方向に30~200μm、周方向に1~5μmの長さの長円形に設定されている。したがって、第1の光ビームAにより多層情報記録媒体100の情報層に対して広い範囲を初期化することが可能である。
図4は、実施の形態1の初期化装置1により初期化される多層情報記録媒体100の断面構成を示す断面図である。
図4に示すように、多層情報記録媒体100は、基板501上に形成された第1の情報層502から第Nの情報層507(但し、Nは3以上の正の整数)まで、N層の情報層が形成されており、情報層間には透明分離層503,504,506が形成されている。また、最後の第Nの情報層507の上(図4においては下側)にはカバー層508が形成されている。ここで、第1の情報層502と第Nの情報層507との間に形成された中間情報層として、第nの情報層505(但し、nは整数であり、2≦n<N)として説明する。
次に、実施の形態1の初期化方法について説明する。初期化対象は、図4に示した3層以上の情報層を有する多層情報記録媒体100である。
図6は、実施の形態1の初期化方法における大きな流れを示すフローチャートである。最初に、ステップS1において初期化装置が起動して初期化が開始される。具体的には、初期化対象である多層情報記録媒体100が、スピンドルモータ2を設けた情報記録媒体装着部に装着されて、回転する。次に、ステップS2において、光ビームが入射される光ビーム入射面から最も遠い位置にある情報層、即ち、多層情報記録媒体100における第1の情報層502の記録膜に対する初期化処理が行われる。第1の情報層502の記録膜に対する初期化処理が終了すると、次の第2の情報層の記録膜に対する初期化処理を行う。第2の情報層の記録膜に対する初期化処理が終了すると、次の情報層であるカバー層508の方向にある情報層の記録膜に対する初期化処理を行う。このように、基板501側からカバー層508の方向に向かって各情報層の記録膜に対して順次初期化処理が行われる。図6に示すフローチャートにおいては、ステップS(n+1)として、中間の情報層である第nの情報層505の初期化処理を行っており、ステップS(N+1)として、カバー層508に最も近い情報層、即ち光ビーム入射面に最も近い第Nの情報層507の初期化処理を行っている。但し、nとNは、2≦n<Nの関係を有する。ステップS(N+1)において、多層情報記録媒体100における光ビーム入射面に最も近い第Nの情報層507の記録膜に対する初期化処理が終了すると、全ての情報層に対する初期化処理が終了し、スピンドルモータ2の回転を停止して当該多層情報記録媒体100に対する初期化が完了する(ステップS(Final))。
最初に、ステップS101において、当該第nの情報層505の初期化処理のための初期設定が行われる。具体的には、移送台4を初期化開始位置に移動し、当該多層情報記録媒体100のカバー層508の表面(光ビーム入射面)と対物レンズ20(図2参照)との間を予め設定されている所定の距離に調整する。
次に、ステップS103において、第1の光源10からの第1の光ビームAを用いて部分初期化を行う。この部分初期化は、当該多層情報記録媒体100において記録再生に用いない領域(フォーカス調整用初期化領域、例えば、ディスクの最内周の領域)における記録膜の一部を初期化(結晶化)するものである。部分初期化は、初期化(結晶化)に十分な第1の光ビームAのフォーカス位置を、多層情報記録媒体100に対して、厚み方向(上下方向)に相対的に往復移動させるものである。部分初期化において、第1の光源10は光学コントローラ8からの制御信号に基づき第1の駆動回路6Aにより駆動される。このように、初期化に十分なパワーを有する第1の光ビームAのフォーカス位置を厚み方向(上下方向)に振ることにより、第nの情報層の記録膜を含め他の情報層の記録膜の一部が初期化される。
なお、ステップS107とステップS108における第1の光ビームAのパワー設定と、移送台4の移動開始の各ステップは、順番が逆になってもよい。また、ステップS101からステップS108までのステップは、当該多層情報記録媒体100におけるデータ記録再生の領域外で行わなければならない。
以下、本発明に係る実施の形態2の初期化方法および初期化装置について説明する。なお、実施の形態2において前述の実施の形態1と異なる点は、初期化方法である。実施の形態2の初期化装置は、実施の形態1の初期化装置の構成と実質的に同様の構成を有するため、実施の形態2において実施の形態1と同じ機能、構成を示すものには同じ符号を付して、その説明は実施の形態1の説明を適用する。
次に、ステップS203において、第1の光源10からの第1の光ビームAを用いて部分初期化を行う。この部分初期化は、当該多層情報記録媒体100において記録再生に用いない領域(フォーカス調整用初期化領域、例えば、ディスクの最内周の領域)における記録膜の一部を初期化(結晶化)するものである。部分初期化は、前述の実施の形態1において説明したように、初期化(結晶化)に十分な第1の光ビームAのフォーカス位置を、多層情報記録媒体100に対して、厚み方向(上下方向)に相対的に往復移動させるものである。このように、初期化に十分なパワーを有する第1の光ビームAのフォーカス位置を厚み方向(上下方向)に振ることにより、第nの情報層の記録膜を含め他の情報層の記録膜の一部が初期化される。実施の形態2の初期化方法における部分初期化は、実施の形態1の初期化方法と同じように実行される。
なお、ステップS208とステップS209における第1の光ビームAのパワー設定と、移送台4の移動開始の各ステップは、順番が逆になってもよい。
始めに、基板側である第1の情報層の初期化処理を行った。この第1の情報層に対する初期化処理においては、図7に示すステップS103の部分初期化を行わずに、第1の光ビームAによりフォーカス調整し、そして第1の光ビームAにより初期化を行った。初期化処理時における、多層情報記録媒体に対する線速度は8m/sであり、移送台4の送り速度は20μmであり、第1の光源10のパワーは2400mWであった。
始めに、基板側である第1の情報層の初期化処理を行った。この第1の情報層に対する初期化処理においては、図8に示すステップS203の部分初期化を行わずに、第1の光ビームAによりフォーカス調整し、そして第1の光ビームAにより初期化を行った。初期化処理時における、多層情報記録媒体に対する線速度は8m/sであり、移送台4の送り速度は20μmであり、第1の光源10のパワーは3800mWであった。
2 スピンドルモータ
3 光学ヘッド
4 移送台
5 移動手段
6 駆動部
7 フォーカス位置制御部
8 光学コントローラ
100 多層情報記録媒体
10 第1の光源
11 第2の光源
12,13 コリメータレンズ
14,15 ビームスプリッター
16,17 1/4波長板
18 波長選択性ミラー
19 ボイスコイル
20 対物レンズ
21 光路補正手段
22 第1のフォーカスエラー検出器
23 第1のフォーカスエラー検出器
26 第1のフォーカスエラー回路
27 第2のフォーカスエラー回路
28 切り替え回路
Claims (26)
- 少なくとも2層以上の情報層を有する情報記録媒体を初期化する初期化方法であって、
前記情報層が有する記録膜に対して、初期化用の波長を有する第1の光ビームにより前記記録膜の一部の領域を部分初期化するステップ、
前記情報記録媒体において情報を記録再生するための波長に対応した波長を有する第2の光ビームにより、前記記録膜における部分初期化された領域を照射するステップ、
前記第2の光ビームの照射により生じる前記情報層からの反射光により生成されたフォーカスエラー信号に基づいて、フォーカス位置を調整するステップ、
フォーカス位置が調整された前記第1の光ビームを前記情報記録媒体に照射することにより前記記録膜の初期化を行うことを特徴とする情報記録媒体の初期化方法。 - 前記第1の光ビームにより前記記録膜の一部の領域を部分初期化するステップにおいて、前記第1の光ビームは、前記記録膜における記録再生領域以外のフォーカス調整用初期化領域を部分的に初期化し、
前記第2の光ビームにより前記情報記録媒体を照射するステップにおいて、部分的に初期化された前記フォーカス調整用初期化領域に対して前記第2の光ビームを照射することを特徴とする請求項1に記載の情報記録媒体の初期化方法。 - 前記情報記録媒体は、N個(但し、Nは3以上の整数)の前記情報層を含むことを特徴とする請求項2に記載の情報記録媒体の初期化方法。
- 前記情報記録媒体は、N個(但し、Nは3以上の整数)の前記情報層を含み、光ビーム入射側より最も遠い情報層から順に、第1の情報層、・・・、第nの情報層(但し、nは整数であり、2≦n<Nの関係を有する)、・・・、および第Nの情報層を有する場合において、
少なくとも第nの情報層における前記記録膜に対して、前記第1の光ビームにより前記記録膜の一部の領域を部分初期化するステップにおいて、
前記第1の光ビームは、前記記録膜における記録再生領域以外のフォーカス調整用初期化領域を部分的に初期化し、
前記第2の光ビームにより前記情報記録媒体を照射するステップにおいて、部分的に初期化された前記フォーカス調整用初期化領域に対して前記第2の光ビームを照射することを特徴とする請求項1に記載の情報記録媒体の初期化方法。 - 第Nの情報層における前記記録膜に対して、前記第1の光ビームにより前記記録膜の一部の領域を部分初期化するステップにおいて、
前記第1の光ビームは、前記記録膜における記録再生領域以外のフォーカス調整用初期化領域を部分的に初期化し、
前記第2の光ビームにより前記情報記録媒体を照射するステップにおいて、部分的に初期化された前記フォーカス調整用初期化領域に対して前記第2の光ビームを照射することを特徴とする請求項4に記載の情報記録媒体の初期化方法。 - 前記フォーカス調整用初期化領域を部分的に初期化するステップにおいて、前記第1の光ビームのフォーカスの位置を、前記情報記録媒体の厚み方向に往復移動させて、N個の情報層の全ての前記記録膜を部分的に初期化することを特徴とする請求項3に記載の情報記録媒体の初期化方法。
- 前記フォーカス調整用初期化領域を部分的に初期化するステップにおいて、前記第1の光ビームのフォーカス位置を、前記情報記録媒体の厚み方向に往復移動させる場合において、前記第1の光ビームのフォーカス位置の往路動作方向路と復路動作方向で前記第1の光ビームのパワーが異なることを特徴とする請求項2に記載の情報記録媒体の初期化方法。
- 前記フォーカス調整用初期化領域を部分的に初期化するステップにおいて、前記第1の光ビームのフォーカス位置を、前記情報記録媒体の厚み方向に往復移動させる場合において、前記情報記録媒体の光ビーム入射側へ近づく移動時の前記第1の光ビームのパワーが、前記情報記録媒体の光ビーム入射側から離れていく移動時の前記第1の光ビームのパワーより大きいことを特徴とする請求項7に記載の情報記録媒体の初期化方法。
- 前記第1の光ビームの波長は、630~850nmの範囲内であることを特徴とする請求項1に記載の情報記録媒体の初期化方法。
- 前記第2の光ビームの波長は、前記情報記録媒体において情報を記録再生するための波長の±60nmの範囲内であることを特徴とする請求項1に記載の情報記録媒体の初期化方法。
- 前記第2の光ビームの波長は、前記情報記録媒体前記情報記録媒体において情報を記録再生するための波長の±20nmの範囲内であることを特徴とする請求項1に記載の情報記録媒体の初期化方法。
- 前記第2の光ビームのスポットサイズは、前記第1の光ビームのスポットサイズより小さいことを特徴とする請求項1に記載の情報記録媒体の初期化方法。
- 前記第2の光ビームのスポット位置は、初期化進行方向に対して、前記第1の光ビームのスポット位置よりも後方であることを特徴とする請求項1に記載の情報記録媒体の初期化方法。
- 前記第1の光ビームのフォーカス位置を前記記録膜の位置に合わせるステップにおいて、
前記記録膜からの反射光をもとに生成されるフォーカスエラー信号に基づいてフォーカス位置の制御を、前記第2の光ビームを用いて行った後、前記第1の光ビームに切り替えて再度行うことを特徴とする請求項1に記載の情報記録媒体の初期化方法。 - 前記第1の光ビームにより前記記録膜の初期化の実行時において、前記第2の光ビームを前記記録膜に照射しないことを特徴とする請求項14に記載の情報記録媒体の初期化方法。
- 少なくとも2層以上の情報層を有する情報記録媒体であって、
前記情報層が有する記録膜における記録再生領域以外の領域にフォーカス調整用初期化領域が形成されており、
前記フォーカス調整用初期化領域が初期化用の波長を有する第1の光ビームにより部分的に初期化されて、前記情報記録媒体において情報を記録再生するための波長に対応した波長を有する第2の光ビームにより前記フォーカス調整用初期化領域が照射されて、前記情報層からの反射光により生成されたフォーカスエラー信号に基づいて、フォーカス位置を調整することにより、フォーカス位置が調整された前記第1の光ビームにより前記記録膜の初期化を行って製造されたことを特徴とする情報記録媒体。 - 前記第2の光ビームが照射されたときの前記記録膜において、初期化状態での反射率が未初期化状態の反射率より高いことを特徴とする請求項16に記載の情報記録媒体。
- 前記情報記録媒体の各情報層間の距離が30μm以下であることを特徴とする請求項16に記載の情報記録媒体。
- 情報記録媒体における記録膜を初期化するための初期化装置であって、
前記初期化装置は、前記記録膜に光ビームを照射する少なくとも1つの光学ヘッドを備え、
前記光学ヘッドは、初期化用の波長を有する第1の光ビームを出射する第1の光源、前記情報記録媒体において情報を記録再生するための波長に対応した波長を有する第2の光ビームを出射する第2の光源、前記第1の光ビームと前記第2の光ビームを前記記録膜に集光させる対物レンズ、および少なくとも一つの光ビームのフォーカス位置制御を行うフォーカス位置制御部、を具備することを特徴とする情報記録媒体の初期化装置。 - 前記初期化装置は、前記記録膜に集光させるための対物レンズを、前記情報記録媒体の厚み方向に移動させる機構を有することを特徴とする請求項19に記載の情報記録媒体の初期化装置。
- 前記第1の光ビームの波長は、630~850nmの範囲内であることを特徴とする請求項19に記載の情報記録媒体の初期化装置。
- 前記第2の光ビームの波長は、前記情報記録媒体において情報を記録再生するための波長の±60nmの範囲内であることを特徴とする請求項19に記載の情報記録媒体の初期化装置。
- 前記第2の光ビームのスポットサイズは、前記第1の光ビームのスポットサイズより小さいことを特徴とする請求項19に記載の情報記録媒体の初期化装置。
- 前記第2の光ビームのスポット位置は、初期化進行方向に対して、前記第1の光ビームのスポット位置よりも後方であることを特徴とする請求項19に記載の情報記録媒体の初期化装置。
- 前記フォーカス位置制御部は、前記第1の光ビームと前記第2の光ビームのフォーカス位置を制御するよう構成されたことを特徴とする請求項19に記載の情報記録媒体の初期化装置。
- 前記対物レンズの開口数NAが0.6以上であることを特徴とする請求項19に記載の情報記録媒体の初期化装置。
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US12/741,113 US8040765B2 (en) | 2008-09-05 | 2009-09-02 | Initialization method for information recording medium, initialization apparatus for information recording medium, and information recording medium |
JP2010527696A JP5450423B2 (ja) | 2008-09-05 | 2009-09-02 | 情報記録媒体の初期化方法、情報記録媒体の初期化装置および情報記録媒体 |
CN2009801008898A CN102067217B (zh) | 2008-09-05 | 2009-09-02 | 信息记录介质的初始化方法、信息记录介质的初始化装置和信息记录介质 |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2008227924 | 2008-09-05 | ||
JP2008-227924 | 2008-09-05 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2010026744A1 true WO2010026744A1 (ja) | 2010-03-11 |
Family
ID=41796928
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2009/004316 WO2010026744A1 (ja) | 2008-09-05 | 2009-09-02 | 情報記録媒体の初期化方法、情報記録媒体の初期化装置および情報記録媒体 |
Country Status (4)
Country | Link |
---|---|
US (1) | US8040765B2 (ja) |
JP (1) | JP5450423B2 (ja) |
CN (1) | CN102067217B (ja) |
WO (1) | WO2010026744A1 (ja) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2011048866A (ja) * | 2009-08-25 | 2011-03-10 | Hitachi Computer Peripherals Co Ltd | 2波長レーザ照射装置及び同装置のフォーカス制御方法 |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP5377552B2 (ja) * | 2011-03-17 | 2013-12-25 | 株式会社東芝 | フォーカスサーボ制御装置、及びそれを用いた情報記録再生装置 |
Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2001023236A (ja) * | 1999-07-12 | 2001-01-26 | Matsushita Electric Ind Co Ltd | 光学情報記録媒体およびその初期化方法 |
JP2003022538A (ja) * | 2001-07-09 | 2003-01-24 | Sony Corp | 光記録媒体の初期化装置および初期化方法 |
JP2003272172A (ja) * | 2002-03-20 | 2003-09-26 | Ricoh Co Ltd | 光ディスク初期化方法及び初期化装置 |
JP2004005865A (ja) * | 2001-06-14 | 2004-01-08 | Matsushita Electric Ind Co Ltd | 光学情報記録媒体とその製造方法および初期化装置 |
JP2004013988A (ja) * | 2002-06-06 | 2004-01-15 | Hitachi Computer Peripherals Co Ltd | フォーカス制御方法およびこれを用いた光記録媒体初期化装置 |
JP2005092927A (ja) * | 2003-09-12 | 2005-04-07 | Victor Co Of Japan Ltd | 多層光ディスク |
WO2009072238A1 (ja) * | 2007-12-03 | 2009-06-11 | Panasonic Corporation | 光学式記録媒体の初期化方法および初期化装置 |
Family Cites Families (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN1010519B (zh) * | 1985-09-25 | 1990-11-21 | 松下电器产业株式会社 | 可逆的光学情报记录介质 |
JPH0832482B2 (ja) | 1986-09-22 | 1996-03-29 | 松下電器産業株式会社 | 光学的情報記録媒体 |
JPS63142548A (ja) * | 1986-12-04 | 1988-06-14 | Matsushita Electric Ind Co Ltd | 書換え型光デイスク |
JPH0991700A (ja) * | 1995-09-25 | 1997-04-04 | Sony Corp | 光学記録媒体の初期化方法とこれに用いる初期化装置 |
JP3302919B2 (ja) * | 1997-11-27 | 2002-07-15 | 株式会社リコー | 光記録媒体の初期化方法及び初期化装置 |
DE60042477D1 (de) * | 1999-07-12 | 2009-08-13 | Panasonic Corp | Optisches informationsaufzeichnungsmedium und verfahren zur initialisierung desselben |
JP3389190B2 (ja) | 2000-01-26 | 2003-03-24 | 健司 川口 | 液温度制御回路 |
TWI228714B (en) * | 2001-06-14 | 2005-03-01 | Matsushita Electric Ind Co Ltd | Optical information recording medium, method for manufacturing the same, and initialization device |
JP3867589B2 (ja) * | 2002-02-22 | 2007-01-10 | ソニー株式会社 | 光学記録媒体の初期化方法 |
JP2003303422A (ja) * | 2002-04-09 | 2003-10-24 | Matsushita Electric Ind Co Ltd | 光学的情報記録媒体の製造方法および光学的情報記録媒体 |
JP2004022116A (ja) * | 2002-06-19 | 2004-01-22 | Digital Stream:Kk | 多層記録層構成の相変化型光ディスク初期化方法および初期化装置 |
JP2005332489A (ja) * | 2004-05-20 | 2005-12-02 | Hitachi Maxell Ltd | 多層型記録媒体の初期化方法及び初期化装置 |
JP2006031844A (ja) * | 2004-07-16 | 2006-02-02 | Hitachi Maxell Ltd | 多層型記録媒体の初期化方法及び初期化装置 |
JP4517954B2 (ja) * | 2005-06-24 | 2010-08-04 | ソニー株式会社 | 光記録媒体の初期化方法 |
-
2009
- 2009-09-02 CN CN2009801008898A patent/CN102067217B/zh active Active
- 2009-09-02 JP JP2010527696A patent/JP5450423B2/ja active Active
- 2009-09-02 WO PCT/JP2009/004316 patent/WO2010026744A1/ja active Application Filing
- 2009-09-02 US US12/741,113 patent/US8040765B2/en not_active Expired - Fee Related
Patent Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2001023236A (ja) * | 1999-07-12 | 2001-01-26 | Matsushita Electric Ind Co Ltd | 光学情報記録媒体およびその初期化方法 |
JP2004005865A (ja) * | 2001-06-14 | 2004-01-08 | Matsushita Electric Ind Co Ltd | 光学情報記録媒体とその製造方法および初期化装置 |
JP2003022538A (ja) * | 2001-07-09 | 2003-01-24 | Sony Corp | 光記録媒体の初期化装置および初期化方法 |
JP2003272172A (ja) * | 2002-03-20 | 2003-09-26 | Ricoh Co Ltd | 光ディスク初期化方法及び初期化装置 |
JP2004013988A (ja) * | 2002-06-06 | 2004-01-15 | Hitachi Computer Peripherals Co Ltd | フォーカス制御方法およびこれを用いた光記録媒体初期化装置 |
JP2005092927A (ja) * | 2003-09-12 | 2005-04-07 | Victor Co Of Japan Ltd | 多層光ディスク |
WO2009072238A1 (ja) * | 2007-12-03 | 2009-06-11 | Panasonic Corporation | 光学式記録媒体の初期化方法および初期化装置 |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2011048866A (ja) * | 2009-08-25 | 2011-03-10 | Hitachi Computer Peripherals Co Ltd | 2波長レーザ照射装置及び同装置のフォーカス制御方法 |
Also Published As
Publication number | Publication date |
---|---|
CN102067217B (zh) | 2013-09-25 |
US20100254233A1 (en) | 2010-10-07 |
CN102067217A (zh) | 2011-05-18 |
JPWO2010026744A1 (ja) | 2012-01-26 |
US8040765B2 (en) | 2011-10-18 |
JP5450423B2 (ja) | 2014-03-26 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
WO2010013321A1 (ja) | 光記録媒体 | |
WO2011045903A1 (ja) | 光記録媒体、光記録媒体の製造方法 | |
JP2006269040A (ja) | 光情報記録媒体、及び光情報記録媒体再生装置 | |
JP5450423B2 (ja) | 情報記録媒体の初期化方法、情報記録媒体の初期化装置および情報記録媒体 | |
US7376070B2 (en) | Optical information recording medium and method for manufacturing the medium | |
JP2005196942A (ja) | 光学的情報記録媒体およびその製造方法 | |
JP4375021B2 (ja) | 光学記録媒体の初期化方法 | |
JP3867589B2 (ja) | 光学記録媒体の初期化方法 | |
EP1494219B1 (en) | Optical information recording medium | |
US8565057B2 (en) | Multilayer optical recording medium | |
JP4014942B2 (ja) | 光学情報記録媒体とその製造方法および初期化装置 | |
JP2011040110A (ja) | 光学式記録媒体の初期化方法および初期化装置 | |
JP5229222B2 (ja) | 光学情報記録媒体及び光学情報再生装置,光学情報再生方法,光学情報再生用プログラム | |
JP2002279707A (ja) | 片面2層ディスクの作製方法、該2層ディスク及び記録再生装置 | |
WO2010061557A1 (ja) | 情報記録媒体、記録装置、再生装置および再生方法 | |
US8743672B2 (en) | Optical disk manufacturing apparatus and optical disk manufacturing method | |
JP5507580B2 (ja) | 光学的情報記録方法、光学的情報記録装置、光学的情報再生方法、光学的情報再生装置および光学的情報記録媒体 | |
JP2010182387A (ja) | 光学式記録媒体の初期化方法および初期化装置 | |
JP2005141799A (ja) | 光記録媒体の製造装置及びその製造方法 | |
WO2003034411A1 (fr) | Procede et appareil permettant d'initialiser un support d'enregistrement optique de type a couche d'enregistrement multicouches | |
WO2010064372A1 (ja) | 情報記録媒体、記録装置、再生装置および再生方法 | |
JP2003217186A (ja) | 相変化型光ディスクの初期化方法および初期化装置 | |
JP2012018730A (ja) | 光記録再生方法、光記録再生装置 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
WWE | Wipo information: entry into national phase |
Ref document number: 200980100889.8 Country of ref document: CN |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2010527696 Country of ref document: JP |
|
WWE | Wipo information: entry into national phase |
Ref document number: 12741113 Country of ref document: US |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 09811274 Country of ref document: EP Kind code of ref document: A1 |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
122 | Ep: pct application non-entry in european phase |
Ref document number: 09811274 Country of ref document: EP Kind code of ref document: A1 |