JP2008090932A - Information recording medium and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an information recording medium wherein eccentricity upon disk driving can be reduced when recording/reproduction of the information recording medium (an optical disk) having flexibility is performed by an optical disk recording and reproducing device provided with an attitude control-cum-optical compensation plate. <P>SOLUTION: The information recording medium provided with a disk like substrate has a projecting region having a prescribed gradient toward an end surface of an inner peripheral hole provided in the center of the substrate. The gradient of the projecting region is coincident with the gradient of a tapered part of a supporting body which is used for supporting the information recording medium in the recording and reproducing device performing recording and reproduction of information and has a tapered shape. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an information recording medium provided with a disk-shaped substrate and a method for manufacturing the same, and more particularly to a shape of an information recording medium for controlling eccentricity during recording and reproduction of the information recording medium and a method for manufacturing the same.

  Conventionally, companies that handle important and enormous amounts of data have adopted data management systems that rely only on magnetic tapes and hard disks. However, the magnetic tape needs to be regularly maintained to prevent adhesion between the tapes, and this maintenance costs high. Also, since a hard disk has a pair of drive and magnetic recording medium, if the drive fails, information recorded on the magnetic recording medium paired with the drive cannot be reproduced. For this reason, it is necessary to take measures such as mirroring data in preparation for a drive failure, but even if such measures are taken, the mirrored disk and the original disk fail at the same time. In the case of a failure or when the mirrored disk further fails before the data recovery is completed when a failure occurs, the data cannot be recovered.

  Therefore, recently, a data management system that uses a part of an optical information recording medium (optical disk) that is easy to maintain and highly reliable has attracted attention. In a management system that partially uses an optical disk, a hard disk or the like is used for data that is frequently rewritten, and an optical disk is used for data that requires little storage but requires long-term storage of information. ing. The optical disk is basically maintenance-free as long as it prevents the deterioration of characteristics due to dust, etc. Unlike the hard disk, there is no problem if the optical disk is moved to another drive even if the recording / playback drive fails. . In other words, by using an optical disc, the time required for troubleshooting can be drastically reduced, and the risk of losing important information is greatly reduced.

  As described above, the optical disk has already occupied an important position as a recording medium that is easy to maintain and has high reliability. However, with the recent development of information communication technology, further improvement in handling ease and storage capacity are achieved. Expectations are gathered for the increase. Here, in order to increase the storage capacity of the optical disc, it is necessary to reduce the track interval (track pitch) and the interval of the recording marks. However, if the track spacing or recording mark spacing is smaller than the laser beam spot diameter λ / NA (λ: wavelength of the laser beam, NA: numerical aperture of the aperture lens), a plurality of recording marks are included in one light spot. As a result, the individual recording marks cannot be identified. That is, the recording capacity of the optical disk is determined by the wavelength of the laser beam and the numerical aperture, and it is impossible to increase the capacity beyond this limit unless a special method is used.

  Various methods such as optical super-resolution, magnetic super-resolution method, super lens, hologram, etc. have been made as a method of increasing the capacity of an optical disk beyond such an upper limit, For example, the recording capacity per volume can be increased by reducing the thickness of the optical disk substrate. For example, as described in Patent Documents 1 to 3, a conventional optical disc is configured by configuring a recording / reproducing device that combines a thin optical disc and a stabilizer for stably rotating the thin optical disc without causing surface blurring. Compared to, a thin optical disk recording / reproducing apparatus having a recording capacity per volume several times larger is realized. An optical disk made of a thin substrate having a thickness of about 100 μm used here is hereinafter referred to as a “flexible disk”.

  As another method of using the flexible disk, there is a method of supporting the flexible disk using a disk-shaped glass plate having a plane dimensional shape substantially the same as that of the flexible disk, in addition to using the stabilizer as described above. The glass plate is made of optical glass, and recording / reproduction can be performed in the same manner as a conventional optical disc when a laser beam for recording / reproduction is irradiated onto the flexible disc through the glass plate (that is, optical). By performing the correction, compatibility with the optical system of the conventional optical disc recording / reproducing apparatus is ensured). For example, when a disc-shaped optical glass plate having a thickness of 500 μm is placed on a flexible optical disc having a thickness of 100 μm on which a DVD pit pattern is transferred and the center is substantially overlapped is reproduced using a commercially available DVD drive, It can be confirmed that information engraved as a pit pattern on the flexible optical disc can be reproduced. The disc-shaped optical glass plate used here supports the flexible disk and corrects the optical path difference with respect to the recording / reproducing laser beam. Therefore, it is hereinafter referred to as “attitude control and optical correction plate”. .

  In a recording / reproducing apparatus using a flexible optical disk, the latter method using the attitude control and optical correction plate is more economically advantageous because the system can be constructed more simply.

JP-A-62-212935. JP2003-331561A. JP2003-91970A.

  By the way, many of the shapes of the disk support part of a DVD drive are tapered cone shape. This is to prevent rotational fluctuations due to variations in the size of the inner circumferential hole of the disc, and by making the disc support portion in this shape, the eccentricity of the DVD disc when driving the disc can be reduced. It has become.

  However, when the posture control / optical correction plate is used for recording / reproduction of the flexible disk described above, a gap between the tapered cone and the inner peripheral hole of the disk is generated by the thickness of the posture control / optical correction plate. Causes eccentricity in time.

  The present invention has been made in view of such a problem. When a flexible information recording medium (optical disk) is recorded / reproduced by a recording / reproducing apparatus including an attitude control / optical correction plate, the disk is recorded. An information recording medium capable of reducing eccentricity during driving and a method for manufacturing the same are provided.

  In order to solve the above problems, an information recording medium according to the present invention is an information recording medium provided with a disk-shaped substrate, and has a predetermined gradient toward an end surface of an inner peripheral hole provided in the center of the substrate. It has the convex area | region which has.

  Here, the gradient of the convex region is a support for supporting the information recording medium in the recording / reproducing apparatus for recording / reproducing information, and matches the gradient of the tapered portion of the support having a tapered shape. The substrate has flexibility.

  A method for manufacturing a disc-shaped information recording medium according to the present invention includes a step of forming a hole in a substrate, a center pin inserted into the hole of the substrate, a mirror mold having a recess around the center pin, and a predetermined pattern. A step of sandwiching the substrate with a stamper mold for transferring to the substrate, a step of applying heat and pressure to the substrate, a step of cooling the substrate, removing the stamper mold, and recording at least on the substrate And a step of forming a layer.

  The method for manufacturing a disc-shaped information recording medium according to the present invention includes a step of forming a hole in a substrate, a center pin to be inserted into the hole of the substrate, a recess around the center pin, and a predetermined pattern on the substrate. A step of sandwiching the substrate between a stamper mold for transfer to a mirror mold, a step of applying heat and pressure to the substrate, a step of cooling the substrate, removing the stamper mold, and And a step of forming at least a recording layer thereon.

  In the manufacturing method, the concave portion around the center pin is a support for the information recording medium in a recording / reproducing apparatus for recording / reproducing information with respect to the information recording medium, and is a tapered portion of the support having a tapered shape. It has a gradient opposite to the gradient.

  Further features of the present invention will become apparent from the best mode for carrying out the present invention and the accompanying drawings.

  According to the information recording medium of the present invention, the shape of the end face of the inner peripheral hole of the flexible disk and the shape of the tapered cone of the disk support of the recording / reproducing apparatus are matched (more specifically, the gradients of both are matched). Therefore, the eccentricity when the flexible disk is driven can be reduced. That is, according to the present invention, the end surface of the inner peripheral hole of the flexible disk has a shape having a gradient toward the inner peripheral hole, and the shape of the tapered cone of the disk support of the recording / reproducing apparatus matches the inclination of the end surface of the inner peripheral hole of the flexible disk. By adopting such a shape, it is possible to eliminate the gap between the tapered cone of the disk support and the inner peripheral hole of the flexible disk when the flexible disk is loaded into the information recording / reproducing apparatus, and to reduce the eccentricity during drive driving.

The best mode for carrying out the present invention will be described below in detail with reference to the accompanying drawings.
<Structure of optical information recording medium>
FIGS. 1 and 2 are views showing a state in which a normal flexible disk 102 (without a gradient convex portion 103) is loaded on a tapered cone 201 and an attitude control / optical correction plate 202 which are disk supports of a recording / reproducing apparatus. . FIG. 1 shows a state where the gap between the flexible disk 102 and the tapered cone 201 is uniform over the entire circumference, and the eccentricity during drive driving is reduced. Further, in FIG. 2, the disk chucking position is shifted from the center when loaded, and the gap between the flexible disk 102 and the tapered cone 201 is non-uniform over the entire circumference, resulting in a very large eccentricity during drive driving. Is shown.

  As described above, in order to mount the flexible disk 102 on the tapered cone 201, a very precise operation is required, and much labor is required only for that purpose. When the flexible disk 102 is mounted on the tapered cone 201 by manual work or the like, the state shown in FIG.

<Structure of flexible disk 101>
Therefore, a flexible disk 101 having a new structure for removing such a problem is provided. 3 and 4 are diagrams showing the structure of an optical information recording medium (flexible disk) according to an embodiment of the present invention. In these drawings, the same reference numerals denote the same parts, and the basic configuration and The operation is the same.

  In the embodiment of the present invention, as shown in FIG. 3, the optical information recording medium is a flexible disk 101 in which an inclined surface 103 is formed toward the inner peripheral hole on the end surface of the inner peripheral hole. This is formed by forming an optical recording film on a sheet material having properties. In the flexible disk 101, for example, PC (polycarbonate) having a thickness of 100 μm is used as a material constituting the sheet. In addition to the PC, PET (polyethylene terephthalate) or PEN (polyethylene naphthalate) can be used.

  The flexible disk 101 as an optical information recording medium according to the present embodiment has an outer diameter of 120 mm and an inner diameter of 15 mm. In the inner peripheral hole-reinforced flexible optical disc of the present invention, the information recording area is an annular area between φ48 mm and φ116 mm. However, in the present embodiment, as long as optical information can be recorded and reproduced as a basic shape of the flexible disk, the outer shape, the inner diameter, and the information recording area are not particularly limited.

  In the present embodiment, the gradient convex portion 103 provided on the end surface of the inner peripheral hole of the flexible disk 101 has the shape of the tapered cone 201 of the disk support in the optical information recording / reproducing apparatus for recording / reproducing information on the flexible disk 101. Has the same slope. Note that the material of the tapered cone 201 is not particularly limited as long as it has high rigidity. In addition, as the shape of the tapered cone 201 described above, the dimension is φ15 mm at the location where the end face of the inner peripheral hole of the flexible disk 101 contacts.

  With reference to FIG. 3, the overall configuration of the information recording medium (flexible disk 101) according to the present embodiment will be described. 3A is a side view of the disk, and FIG. 3B is a plan view thereof. The flexible disk 101 according to the present embodiment is formed of, for example, a flexible plastic substrate, and the end surface of the inner peripheral hole at the center thereof is provided with a gradient convex portion 103 toward the inner peripheral hole as shown in FIG. 3A. It has become.

  FIG. 4 is a diagram showing a cross-sectional structure of the single-sided single-layer flexible disk 101. As shown in FIG. 4, a groove-shaped portion made of a groove and a land is formed on a flexible sheet 1011 having a thickness of 100 μm, and a recording layer 1012, a reflective layer 1013, and a protective layer 1014 are sequentially formed thereon. Since the thickness of the recording layer 1012 to the protective layer 1014 is very small with respect to the sheet thickness and can be ignored, the total thickness of the flexible disk 101 is 100 μm. As a matter of course, the light incident surface 1010 is opposite to the surface on which the recording layer 1012 to the protective layer 1014 are formed. Further, the structure of the disc is not limited to one layer on one side, and two layers on one side, two layers on both sides, and four layers on both sides can be used. However, even when a plurality of recording layers are formed, it is desirable that the thickness of one disk is 200 μm or less.

  FIG. 5 is a diagram schematically showing a cartridge containing a plurality of flexible disks 101 shown in FIG. At the time of recording or reproducing, a disc transport device (not shown) has a mechanism for taking out a disc to be recorded or reproduced from the cartridge and transporting it to a predetermined position. For example, if about 200 flexible disks 101 with a recording capacity of 4.7 GB are stored in a cartridge with a thickness of 30 mm, a recording capacity of about 940 GB can be realized as a whole cartridge.

<Outline of recording / reproducing apparatus>
6 and 7 are diagrams showing a schematic configuration of disk reading (writing) of the recording / reproducing apparatus according to the present embodiment. 6 shows a case where information is read / written from the lower surface of the disk, and FIG. 7 shows a case where information is read / written from the upper surface of the disk.

  In FIG. 6, the flexible disk 101 according to the present embodiment is loaded on a tapered cone 201 and an attitude control / optical correction plate 202 which are disk supports of a recording / reproducing apparatus, and is recorded from the lower surface of the disk by a recording / reproducing head (optical pickup) 203. A configuration for recording and reproducing information is adopted. In this case, the gradient convex portion 103 on the inner peripheral end surface of the flexible disk 101 and the gradient of the tapered cone 201 are substantially coincident, and the gap between the flexible disk 101 and the tapered cone 201 is almost eliminated, so that the eccentricity at the time of drive driving can be greatly reduced. It becomes possible. Here, the attitude control / optical correction plate 202 supports the flexible disk 101, and also detects the optical path difference of the laser light emitted from the recording / reproducing head 203 in order to ensure compatibility with the DVD. It is provided to correct.

  The attitude control / optical correction plate 202 and the flexible disk 101 are placed on the turntable 207. The turntable 207 is rotationally controlled by a spindle motor (not shown), and an information recording or reproducing operation is performed by a recording / reproducing head 203 using an optical system similar to a DVD. The flexible disk 101 is placed on the attitude control / optical correction plate 202 and then fixed by a magnet chuck (not shown) to suppress a deviation during rotation. Needless to say, there are various fixing methods, and the magnet chuck in this embodiment is merely an example.

  FIG. 7 shows another mode of recording and reproduction. In this figure, the flexible disk 101 according to the present embodiment is loaded on a tapered cone 201 and a posture control plate 204 which are disk supports of a recording / reproducing apparatus, and information is recorded / reproduced by a recording / reproducing head (optical pickup) 203 from the upper surface of the disk. The structure to do is taken. Also in this case, the gradient convex portion 103 on the inner peripheral end surface of the flexible disk 101 and the gradient of the tapered cone 201 are substantially coincident, and the gap between the flexible disk 101 and the tapered cone 201 is almost eliminated, and the eccentricity at the time of drive driving can be greatly reduced. Is possible. Here, the attitude control plate 204 is provided to support the flexible disk 101 having flexibility.

  The attitude control plate 204 and the flexible disk 101 are placed on the turntable 207. The turntable 207 is rotationally controlled by a spindle motor (not shown), and an information recording or reproducing operation is performed by a recording / reproducing head 203 using an optical system similar to a DVD. The recording / reproducing head 203 is provided with an optical correction plate 205. When the flexible disk 101 according to the present embodiment is recorded / reproduced, the recording / reproducing head 203 is installed on the optical path of the irradiated laser beam, and is used for recording / reproducing a DVD or the like. Is configured to be removed from the optical path of the laser beam. After the flexible disk 101 is placed on the attitude control plate 204, the flexible disk 101 is fixed by a magnet chuck (not shown) to suppress a shift during rotation.

  For the recording / reproduction as described above, whether the configuration of FIG. 6 or the configuration of FIG. 7 is adopted depends on whether the recording layer 1012 or the reflective layer 1013 of the flexible disk 101 is formed on the upper surface or the lower surface of the disk. . Therefore, as will be described later, when the mold and stamper shown in FIG. 11 are used in the disk manufacturing process, the recording / reproducing configuration shown in FIG. 6 is adopted, and when the mold and stamper shown in FIG. 12 is used. The recording / reproducing configuration shown in FIG. 7 is adopted.

<Configuration of posture control / optical correction plate or posture control plate>
FIG. 8 is a diagram showing the structure of the attitude control / optical correction plate 202 or the attitude control plate 204 used when information recording / reproduction is executed on the flexible disk 101 according to the present embodiment. As shown in the figure, the posture control / optical correction plate 202 or the posture control plate 204 has a plurality of vent holes 206 formed around the center.

  The flexible disk 101 has low rigidity and easily has static electricity. Therefore, when either or both of the flexible disk 101 and the attitude control / optical correction plate 202 (orientation control board 204) have static electricity, the flexible disk 101 does not become completely flat and is usually flexible. An area where air is confined is formed between the disk 101 and the attitude control / optical correction plate 202 or the attitude control plate 204 (this phenomenon is referred to as air biting).

  Due to the occurrence of such “air biting”, local deflection of the flexible disk 101 occurs. Therefore, when the flexible disk 101 is loaded into a recording / reproducing apparatus and recorded / reproduced, its posture is stabilized. Need to control. For this purpose, there is no air in the space between the flexible disk 101 and the attitude control / optical correction plate 202 or attitude control plate 204 due to the difference between the substrate thickness in the inner peripheral area of the flexible disk and the substrate thickness other than the inner peripheral area. It is necessary to feed the flow and remove the air bite generated between the flexible disk.

  The posture control / optical correction plate 202 or the posture control plate 204 is provided with a plurality of vent holes 206 for sending an air flow to and from the flexible disk 101. Thereby, the above-mentioned air biting can be removed, and surface blurring due to the air biting can be suppressed. As a result, the flexible disk 101 can be accurately recorded and reproduced by the recording / reproducing apparatus.

  As shown in FIG. 9, for example, if the spacer 208 is installed between the flexible disk 101 and the attitude control / optical correction plate 202 or the attitude control plate 204, and the disk rotates during recording and reproduction, the arrow in FIG. The air flow indicated by is generated and the air bite is removed.

<Method for Manufacturing Flexible Disk 101>
FIG. 10 is a diagram showing a manufacturing process of the flexible disk 101 according to the embodiment of the present invention. The manufacturing process shown in FIG. 10 is only an example, and other manufacturing processes can be used.

  In FIG. 10, first, a flexible thin sheet (thermoplastic plastic film, for example, a sheet of a material of 150 mm × 150 mm PC, PET, PEN or the like) having a thickness of about 100 μm is prepared, and a hole is formed in the center thereof. Open (step S101). In addition, it is preferable to open this hole slightly larger than the target dimension in consideration of heat shrinkage of the material. How much you open depends on the material.

  Next, a stamper having a concavo-convex pattern (for example, a nanoimprint mold) and a mirror mold are prepared, and the thin sheet is sandwiched between them (step S102). As for the stamper and the mirror mold, pairs shown in FIGS. 11 and 12 can be considered.

  In FIG. 11, the stamper 301 includes a center pin 302 into which the thin sheet prepared in step S101 is inserted, a concavo-convex pattern 303, and a disk gradient forming unit for forming the gradient convex portion 103 of the flexible disk 101 on the thin sheet. 304 is provided. The disk gradient forming portion 304 has a gradient opposite to the gradient of the tapered cone 201, and as described above, the gradient convex portion 103 has a depth that is about twice the disk thickness (for example, about 200 μm). Yes. The mirror mold 305 is for forming a light incident surface 1010 (see FIG. 4). Since it is desirable for the light incident surface to be as uneven as possible, a mirror surface mold is used as a mold for forming the light incident surface. If the pair of molds shown in FIG. 11 is used, a disc adopting the recording / reproducing configuration shown in FIG. 6 is generated. That is, if the surface on which the gradient protrusion 103 is extended is the upper surface of the disk, the uneven pattern 303 is transferred to the upper surface (the upper surface of the disk) of the thin sheet, and each layer is formed thereon (described later). In this case, the recording / reproducing head 203 irradiates the lower surface of the disk with laser light. The diameter Φ of the center pin 302 is set slightly larger than the intermediate diameter X (see FIG. 5 or 6) of the tapered cone 201 that is a disk support of the recording / reproducing apparatus. This is for considering the thermal shrinkage of the material of the thin sheet so that the dimension after pressing the sheet matches X.

  On the other hand, in FIG. 12, the mirror mold 305 includes a center pin 302 into which the thin sheet prepared in step S101 is inserted, and a disk gradient forming unit 304 for forming the gradient convex portion 103 of the flexible disk 101 on the thin sheet. The light incident surface 1010 (see FIG. 4) is formed. The disk gradient forming unit 304 has a gradient opposite to the gradient of the tapered cone 201. The stamper 301 includes an uneven pattern 303 and transfers the pattern to a thin sheet. If the pair of molds shown in FIG. 12 is used, a disc adopting the recording / reproducing configuration shown in FIG. 7 is generated. In other words, if the surface on which the gradient convex portion 103 is extended is the upper surface of the disk, the uneven pattern 303 is transferred to the lower surface (the lower surface of the disk) of the thin sheet, and each layer is sequentially formed (described later). In this case, the recording / reproducing head 203 irradiates the upper surface of the disk with laser light.

  The stamper 301 or the mirror surface mold 305 having the center pin 302 first punches a hole into which the center pin 302 is inserted, and generates a concave portion (disk gradient forming portion 304) having a gradient around the hole (center). The center pin 302 is inserted, and the center pin 302 is inserted.

  Subsequently, in step S103, with the thin sheet sandwiched between the stamper 301 and the mirror mold 305, the stamper 301 and the mirror mold 305 are heated (above the glass transition temperature of the plastic sheet), and the sheet is pressed from above and below ( And the uneven pattern 303 of the stamper 301 is transferred. Further, the thermoplastic thin plastic sheet is softened by heating, and the central portion of the sheet hangs down on the disk gradient forming portion 304. As described above, since the disk gradient forming unit 304 has a gradient just opposite to the gradient of the tapered cone 201, the gradient convex portion 103 is formed on the disk by heating the sheet and cooling the next step.

  Then, after the heating and pressurization in step S103 is continued for a predetermined time (a time sufficient for forming the gradient convex portion 103), the stamper 301 and the mirror mold 305 are cooled in that state (step S104). Thereby, the concave / convex pattern 303 and the gradient convex portion 103 are fixed on the flexible disk 101.

  Next, only the stamper 301 is peeled off, and the thin sheet is left on the mirror mold side (step S105).

  Then, with the thin sheet remaining in the mirror mold or peeled off, the outer peripheral portion of the sheet is punched to form the sheet into a disk shape (step S106). Subsequently, a dye for forming a recording layer is applied on the portion where the concavo-convex pattern 303 has been transferred, a reflective layer is further formed thereon, and finally a protective layer is formed (step S107).

  Through the manufacturing process of steps S101 to S107, the flexible disk 101 including the gradient convex portion 103 according to the present embodiment is generated.

  The flexible disk of the present invention has been described with reference to specific embodiments. However, the present invention is not limited to these embodiments, and those skilled in the art can do so without departing from the spirit of the present invention. Various modifications and improvements can be made to the configuration and functions of the invention according to the above-described embodiments or other embodiments.

  The configuration of the information recording medium (optical disk) according to the embodiment of the present invention and the method for manufacturing the recording medium have been described above.

  According to the information recording medium of the present embodiment, the information recording medium is provided with a disk-shaped substrate, and the inner peripheral area has an area having a gradient over the entire circumference toward the end face of the inner peripheral hole. Therefore, it is possible to prevent problems caused by the eccentricity of the disk when the drive is driven.

  In addition, according to the method of manufacturing the information recording medium of the present embodiment, the molding die (nanoimprinting die) on which the concavo-convex pattern is formed, the cylindrical center pin having a convex shape at the center, and the center pin are directed. Using a mirror mold with a predetermined slope (or the molding mold may have a center pin), a thermoplastic film is closely attached in a sandwich between the molding mold and the mirror mold And transferring the concavo-convex pattern onto a predetermined surface of the thermoplastic film by hot pressing with a predetermined pressure and a predetermined heat on the entire mold, mirror mold and thermoplastic film, A shape having a gradient toward the inner peripheral hole is formed in the central portion of the thermoplastic film over the entire inner peripheral hole and the inner peripheral hole end face. As a result, it is possible to easily manufacture a disk having an area having a gradient over the entire circumference in the inner peripheral area of the disk and facing the end surface of the inner peripheral hole. By using the disk, problems due to the occurrence of eccentricity during recording and reproduction can be prevented. be able to.

  Note that when a thermoplastic film is closely attached to a molding die and a mirror mold and is hot-pressed with a predetermined pressure and a predetermined heat, the thermoplastic film has a heat that exceeds the glass transition temperature of the thermoplastic film. Added. The molding die or mirror mold has a circular hole with an inner diameter according to the center pin shape at the center, and the thermoplastic film has an inner diameter according to the center pin shape at the center of the mirror mold. Has a circular hole.

It is a figure which shows the example of a state at the time of loading a general flexible disk in an optical information recording / reproducing apparatus (ideal state without eccentricity). It is a figure which shows the example of the state which eccentricity generate | occur | produced when a general flexible disk is loaded in an optical information recording / reproducing apparatus. FIG. 3A is a configuration diagram showing an overall configuration of an information recording medium (flexible disk) according to the present invention, FIG. 3A shows a side view thereof, and FIG. 3B shows a plan view thereof. It is a figure which shows the cross-section of the information recording medium by this invention. It is a figure which shows a mode that several information recording media by this invention were stored in the cartridge. 1 is a diagram showing a schematic configuration of an information recording / reproducing apparatus when an information recording medium of the present invention is mounted (configuration in which an optical pickup is under a disc). 1 is a diagram (a configuration in which an optical pickup is on a disk) showing a schematic configuration of an information recording / reproducing apparatus when an information recording medium of the present invention is mounted. It is a figure which shows the structural example of the attitude | position control and optical correction board which can be mounted | worn with the information recording / reproducing apparatus of this invention. It is a figure which shows the flow of air at the time of using the attitude | position control and optical correction board of FIG. It is a figure for demonstrating the manufacturing process of the information recording medium by this invention. It is a figure which shows the 1st specific example of the metal mold | die used by the manufacturing process of the information recording medium by this invention. It is a figure which shows the 2nd specific example of the metal mold | die used by the manufacturing process of the information recording medium by this invention.

Explanation of symbols

101. Flexible disk 102 of the present invention General flexible disk 103 Gradient convex portion 201 Tapered cone (disc support)
202 Attitude control and optical correction plate

Claims (6)

  An information recording medium comprising a disc-shaped substrate, wherein the information recording medium has a convex region having a predetermined gradient toward an end surface of an inner peripheral hole provided in the center of the substrate.   The slope of the convex region is a support for supporting the information recording medium in a recording / reproducing apparatus for recording / reproducing information, and is matched with the slope of the tapered portion of the support having a tapered shape. The information recording medium according to claim 1.   The information recording medium according to claim 1, wherein the substrate has flexibility. A method for manufacturing a disk-shaped information recording medium,
Forming a hole in the substrate;
Sandwiching the substrate between a center pin inserted into the hole of the substrate, a mirror mold having a recess around the center pin, and a stamper die for transferring a predetermined pattern to the substrate;
Applying heat and pressure to the substrate;
Cooling the substrate;
Removing the stamper mold and forming at least a recording layer on the substrate;
An information recording medium manufacturing method comprising: A method for manufacturing a disk-shaped information recording medium,
Forming a hole in the substrate;
A center pin inserted into the hole of the substrate, a recess around the center pin, a stamper mold for transferring a predetermined pattern to the substrate, and a step of sandwiching the substrate with a mirror mold;
Applying heat and pressure to the substrate;
Cooling the substrate;
Removing the stamper mold and forming at least a recording layer on the substrate;
An information recording medium manufacturing method comprising:   The concave portion around the center pin is a support of the information recording medium in a recording / reproducing apparatus for recording / reproducing information with respect to the information recording medium, and has a gradient opposite to the gradient of the tapered portion of the tapered support. The method of manufacturing an information recording medium according to claim 4, wherein

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