JP2006216173A - Recording disk manufacturing method, recording disk, disk substrate, and recording/reproduction apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stabilize surface wobbling of a flexible and sheet-like recording disk. <P>SOLUTION: A stiffness k of the recording disk is defined by an expression 1 where E represents a Young's modulus of the recording disk, b represents a diameter of a surface wobbling stabilization member, a represents a radius of the recording disk pressed against the surface wobbling stabilization member, and t represents a thickness of the recording disk. And, an amount of displacement when a position of the recording disk surface is displaced by the surface wobbling stabilization member approaches the recording disk and relatively presses the recording disk, is defined as an amount of deflection W, and a product P (disk parameter) of the stiffness k of the recording disk and the amount of deflection W of the recording disk is represented by an expression 2. The recording disk is manufactured by adjusting the disk parameter. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a flexible recording disk, and more particularly to a method for manufacturing the recording disk, a disk substrate, and a recording / reproducing apparatus.

  Optical discs are widely used as recording media for recording and / or reproduction because they are removable and have a large capacity. Usually, a transfer layer is formed on a polycarbonate substrate of 1.2 mm or 0.6 mm, information is recorded on this transfer layer, and this is reproduced. For recording / reproduction, it is necessary to collect light on the recording surface, and the positional accuracy of the recording surface with respect to the optical pickup is required. Therefore, the above-mentioned positional accuracy is obtained by flattening the substrate and providing rigidity, and applying servo to the optical pickup.

  In order to increase the recording capacity of an optical disk, research and development are being carried out to further reduce the diameter of the light spot by increasing the numerical aperture (NA) of the objective lens or shortening the wavelength of the laser beam. On the other hand, in order to increase the numerical aperture (NA) of the objective lens, it is necessary to reduce the tilt (surface deflection) of the substrate, so that the planar accuracy of the manufacturing substrate is increased, the tilt servo is mounted on the optical pickup, or A tilt margin is increased by providing a thin cover layer of about 0.1 mm on the transfer layer and recording / reproducing from the cover layer side.

  Although it is possible to reduce the surface deflection of the substrate of the optical disk by devising the material or the manufacturing method, the manufacturing cost of the optical disk increases. In addition, mounting a tilt servo on the optical pickup similarly increases the cost of the optical pickup.

  In addition, even in the case of reproducing with an optical pickup from the transfer layer side without passing through the substrate of the optical disk, the distance between the transfer layer surface and the objective lens can be secured only about 0.1 mm. In order to prevent a collision with the objective lens when rotating, it is necessary to reduce the surface shake and to increase the chucking accuracy of the optical disk chucking device. These also increase the cost of the optical disc and the recording / reproducing apparatus.

  Therefore, instead of increasing the mechanical planar accuracy of the rigid optical disk, the optical disk is made flexible so that the surface shakes on the side opposite to the recording / reproducing surface and opposite to the objective lens of the optical pickup. By providing the stabilizing member, the flexible optical disk is sandwiched between the objective lens and the surface stabilization member, and the disk is aerodynamically levitated from the surface stabilization member by the rotation of the optical disk ( Research and development have been made on a technique for stabilizing the position of the recording surface with respect to the objective lens, and at least bringing the tilt (vibration) on the recording surface as close to zero as possible (for example, Bernoulli flying; non-contact) (for example, Patent Document 1).

The principle that the surface runout of the flexible disk can be reduced is determined by the sum of the following (1) to (4).
(1) Force that the surface runout stabilization member pushes the disk aerodynamically
(2) The force with which the disk is resiliently repelled
(3) Pressure field between surface runout stabilization member and disk
(4) Centrifugal force of disk The above (4) is determined by the number of rotations of the disk, and (3) is determined by the amount of gap between the surface runout stabilizing member and the disk. Further, the above (1) and (2) are in a balanced relationship. In (2), the rigidity of the disk and the internal loss that absorbs (1) contribute as parameters. Therefore, it is necessary to manage these parameters.

  In addition, as a conventional method for manufacturing the flexible optical disk (flexible disk), a thermoplastic resin or a thermosetting resin is applied to the surface of a flexible sheet such as a substrate made of PET resin, and a stamper is manufactured. Transfer the fine concavo-convex pattern, heat cure it, then heat transfer method to form a transfer layer, or also apply UV curable resin to the surface of the flexible sheet to transfer the fine pattern of the stamper, UV 2P (Photo Polymerization) method (Patent Document 2) for forming a transfer layer after curing, or heating a flexible organic material sheet to a softening point or higher, pressing and transferring a stamper, and then cooling the sheet There is a method of peeling a stamper (Patent Document 3).

  For example, the prior art described in Patent Document 4 is a direct embossing method in which a transparent substrate is thermocompression bonded. The pressure bonding is performed after the temperature is raised, but it is difficult to make the in-plane temperature variation and stress variation extremely uniform, so that variations tend to occur in optical characteristics, mechanical strength, warpage, and the like. On the other hand, the 2P method is excellent in transferability, and the potential for this portion is superior to other transfer methods.

In the 2P method, the thickness of the flexible disk is the sum of the thicknesses of the substrate to be transferred, the transfer layer, the transfer layer, and the like. Since the disk substrate itself is industrially mass-produced, its thickness distribution is about ± 1 μm. However, a general substrate has a thickness amplitude of about ± 1 μm, but the thickness changes greatly in the circumferential direction and changes in a spike shape.
JP 2003-115108 A Japanese Patent No. 2924430 JP-A-6-60423 Japanese Patent Laid-Open No. 11-273147

  According to the invention in which the surface runout of the disc is stabilized by the air bearing formed between the surface runout stabilizing member and the disc described in Patent Document 1, the surface is made by the flexibility of the disc substrate or the disc. The runout can be stabilized.

  In general, the followability of the focus servo has a limit in the high frequency region of surface shake, and the followability of the focus servo increases the focus error and decreases the recording / reproducing accuracy. This is a major problem when increasing the recording capacity and recording / reproducing speed of a flexible disk.

  In the invention described in Patent Document 1, the air bearing formed between the surface runout stabilizing member and the disk functions, and the disk repulsion force determined by the rigidity of the disk substrate and the guide pushing amount causes the disk to move. Surface runout can be stabilized.

  In the invention described in Patent Document 1, the waviness of the flexible disk is substantially corrected by the air bearing, and the surface runout can be stabilized by the repulsive force applied to the disk substrate. Since the thickness variation of the substrate itself becomes a fixed value and is superimposed on the surface deflection of the disk, the thickness variation needs to be reduced.

  That is, since the disc substrate required for the Blu-ray disc needs to have a function as an optical transmission layer, the birefringence needs to be reduced as much as possible, but the optical disc according to the invention described in Patent Document 1 is required. Since the system uses surface recording, the optical properties may be free. However, it is necessary to limit the characteristics related to the surface properties as much as possible.

  An object of the present invention is to define the rigidity and repulsive force of a recording disk or a disk substrate in order to solve the above-described conventional problems and stabilize the surface deflection of a flexible sheet-like recording disk. It is an object of the present invention to provide a recording disk manufacturing method, a recording disk and a disk substrate, and a recording / reproducing apparatus devised so as to reduce the variation in thickness of the recording medium as much as possible.

In order to achieve the above object, the present invention has a surface vibration stabilizing member having an arbitrary shape in proximity to a surface opposite to the recording / reproducing surface of a flexible recording disk, and A recording disk used in a recording / reproducing apparatus that performs recording / reproduction with the pickup in a state in which a pickup is disposed on a surface opposite to the surface stabilization member and the surface vibration of the recording disk is reduced. In the manufacturing method,
The rigidity k of the recording disk is defined by the following formula (Equation 1),

（ただし、Ｅ：記録ディスクのヤング率、ｂ：面振れ安定化部材の直径、a：面振れ安定化部材に押圧される記録ディスクの半径、ｔ：記録ディスクの厚み）、
かつ、前記面振れ安定化部材が前記記録ディスクに対して近接して相対的に前記記録ディスクを押し込むことにより、前記記録ディスク表面の位置が変位する際の当該変位量を前記記録ディスクの撓み量Ｗと定義し、前記記録ディスクの剛性ｋと前記記録ディスクの撓み量Ｗとの積Ｐをディスクパラメーターとして、下式（数２）で規定し、

(Where E: Young's modulus of the recording disk, b: diameter of the surface runout stabilization member, a: radius of the recording disk pressed against the surface runout stabilization member, t: thickness of the recording disk),
Further, when the surface vibration stabilizing member pushes the recording disk relatively close to the recording disk, the amount of displacement when the position of the surface of the recording disk is displaced is the amount of bending of the recording disk. W is defined, and the product P of the recording disk stiffness k and the deflection amount W of the recording disk is defined as a disk parameter by the following equation (Equation 2).

前記ディスクパラメーターを調整して記録ディスクを製造することを特徴とし、記録ディスクの剛性を記録ディスク（ディスク基板として捉えてもよい）のヤング率，厚み，面振れ安定化部材に押圧される記録ディスクの部位における半径，面振れ安定化部材の直径の４つのパラメーターで規定し、さらに前記のようにディスク撓み量を定義し、ディスク剛性とディスク撓み量との積をディスクパラメーターとして、ディスク面振れを空気力学的に安定化させ、記録／再生を行うものである。

A recording disk manufactured by adjusting the disk parameters, wherein the rigidity of the recording disk is pressed against a Young's modulus, thickness, and surface runout stabilizing member of the recording disk (may be regarded as a disk substrate) The disk deflection is defined by the four parameters of the radius and the diameter of the surface deflection stabilizing member, the disk deflection is defined as described above, and the product of the disk stiffness and the disk deflection is defined as the disk parameter. It is stabilized aerodynamically and performs recording / reproduction.

  Further, the present invention is characterized in that a product P of the recording disk rigidity k and the deflection amount W of the recording disk is 0.6 to 2000 mN, and the product P is 0.6 to 2000 mN. As described above, the thickness, Young's modulus, material, and thickness variation in the circumferential direction of the recording disk are set to 10 μm or less.

The present invention also provides a surface vibration stabilizing member having an arbitrary shape close to the surface opposite to the recording / reproducing surface of the recording disk having flexibility, thereby stabilizing the surface vibration with respect to the recording disk. In a recording / reproducing apparatus that performs recording / reproduction with the pickup in a state in which a pickup is disposed on a surface opposite to the member and surface vibration of the recording disk is reduced,
The rigidity k of the recording disk is defined by the following equation (Equation 3),

（ただし、Ｅ：記録ディスクのヤング率、ｂ：面振れ安定化部材の直径、a：面振れ安定化部材に押圧される部位における記録ディスク半径、ｔ：記録ディスクの厚み）、
かつ、前記面振れ安定化部材が前記記録ディスクに対して近接して相対的に前記記録ディスクを押し込むことにより、前記記録ディスク表面の位置が変位する際の当該変位量を前記記録ディスクの撓み量Ｗと定義し、前記記録ディスクの剛性ｋと前記記録ディスクの撓み量Ｗとの積Ｐをディスクパラメーターとして、下式（数４）で規定し、

(Where E: Young's modulus of the recording disk, b: diameter of the surface runout stabilization member, a: radius of the recording disc at the portion pressed against the surface runout stabilization member, t: thickness of the recording disc),
Further, when the surface vibration stabilizing member pushes the recording disk relatively close to the recording disk, the amount of displacement when the position of the surface of the recording disk is displaced is the amount of bending of the recording disk. W is defined, and the product P of the recording disk stiffness k and the deflection amount W of the recording disk is defined as a disk parameter by the following equation (Equation 4):

前記ディスクパラメーターを調整して、ディスク面振れを空気力学的に安定化させて記録／再生を行うことを特徴とする。

Recording / reproducing is performed by adjusting the disk parameters to stabilize the disk runout aerodynamically.

  Further, the present invention provides a means for controlling the deflection amount W of the recording disk such that the product P of the recording disk rigidity k and the deflection amount W of the recording disk is 0.6 to 2000 mN, or the recording disk. A means for controlling the linear velocity during rotation of the disk is provided.

  According to the present invention, high-quality recording / reproduction can be performed by aerodynamically stabilizing the disc surface run-out by using the product of the disc rigidity and the disc deflection amount as a disc parameter, and preferably the disc stiffness And the product of the disk deflection amount is preferably 0.6 to 2000 mN.

  Further, by manufacturing a recording disk and a disk substrate based on the disk parameters, a high-quality flexible recording disk can be obtained.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic configuration diagram of an information recording / reproducing apparatus for explaining an embodiment of the present invention, wherein 1 is an optical disc that is a flexible sheet-like recording disc, and 2 is a hub 3 of the optical disc 1 The spindle shaft 4 performs a spindle motor that rotationally drives the spindle shaft 2, and 5 includes an objective lens 6, a recording unit that writes information to the optical disc 1, and a reproduction unit that reads the written information The optical pickup 7 is a stabilization guide member that is disposed opposite to the optical pickup 5 with the optical disc 1 interposed therebetween and serves as a surface runout stabilization member for preventing the optical disc 1 from shaking.

  Next, stabilization of the surface runout of the flexible sheet-like optical disc in this embodiment will be described.

  During recording / reproduction, the optical disk 1 is rotated between the optical pickup 5 and the stabilizing guide member 7. The rotating optical disk 1 itself is small but rigid, and when it rotates, it has a force to turn straight due to the action of centrifugal force. Therefore, by bringing the stabilization guide member 7 closer to the optical disc 1 and generating a repulsive force P due to the pressure difference of the air flow based on Bernoulli's law and applying it to the optical disc 1, the force that the optical disc 1 tries to straighten. And, due to the balance of the repulsive force from the stabilizing guide member 7, a large surface runout (runout in the disc rotation axis direction) can be reduced.

  In the present embodiment, a columnar stabilizing guide member 7 having an arcuate opposing surface is disposed on the side of the substrate 12 opposite to the recording layer 11 in the optical disc 1, so Recording / reproducing is performed by condensing the light beam L for recording / reproducing. The stabilization guide member 7 stabilizes the substrate 12 side opposite to the recording layer 11.

  In the present embodiment, in the optical disk 1 having flexibility as described above, the disk surface deflection is aerodynamically set by performing setting or drive control of the disk component using the product of the disk rigid body and the disk deflection amount as a disk parameter. Stabilized.

  That is, from the material mechanical knowledge, in the case of the optical disc 1 as in the present embodiment, an arbitrary radial position of the optical disc 1 is pressed by the stabilizing guide member 7 while being fixed to the spindle shaft 2 of the spindle motor 4. This model corresponds to a so-called “cantilever” structure.

  As shown in FIG. 2, the amount of deflection W of the substrate 12 has a relationship represented by the following equation (Equation 5) as the force P, Young's modulus E, radial position a, and inertia moment I received by the substrate 12 (note that Here, the substrate includes the concept of the entire disk and the disk substrate alone).

ここで、安定化ガイド部材７の位置（Ｐの位置の直下、すなわち半径位置ａ）と、撓み量を計測している位置（測定器であるレーザ変位計の直上；長さｘ）とが同じ位置であるので、ｘ＝ａより、下式（数６）に示すようになる。

Here, the position of the stabilizing guide member 7 (immediately below the position of P, that is, the radial position a) is the same as the position at which the amount of deflection is measured (immediately above the laser displacement meter as the measuring instrument; length x). Since it is a position, from x = a, the following equation (Equation 6) is obtained.

ここで、ばね係数を考慮して（力Ｆ＝ｋ×変位量ｘ；ｋはバネ定数：基板の剛性に相当する）に当てはめることにより、下式（数７）で表すことができる。

Here, considering the spring coefficient (force F = k × displacement amount x; k is a spring constant: corresponding to the rigidity of the substrate), it can be expressed by the following equation (Expression 7).

半径位置ａでの慣性モーメントＩは、図３に示すように、横長さｂ（安定化ガイド部材７の直径に相当）、高さ（厚み）ｔとすると、下式（数８）に示すようになる。

As shown in FIG. 3, the moment of inertia I at the radial position a is represented by the following equation (Equation 8) when the lateral length b (corresponding to the diameter of the stabilizing guide member 7) and the height (thickness) t are obtained. become.

したがって、基板１２の剛性ｋは下式（数９）で与えられる。

Accordingly, the rigidity k of the substrate 12 is given by the following equation (Equation 9).

基板１２の剛性ｋは、基板のヤング率Ｅ，厚みｔ，半径位置ａ、安定化ガイド部材７の直径ｂの４つのディスクパラメーターで規定されることになる。この基板１２の剛性ｋに基板１２の撓み量Ｗを掛けた値が、安定化ガイド部材７が基板１２を押し込む力であり、したがって、下式（数１０）にて基板１２の反発力Ｐを定義することができる。

The rigidity k of the substrate 12 is defined by four disk parameters of the substrate Young's modulus E, thickness t, radius position a, and diameter b of the stabilizing guide member 7. The value obtained by multiplying the rigidity k of the substrate 12 by the deflection amount W of the substrate 12 is the force with which the stabilization guide member 7 pushes the substrate 12, and therefore the repulsive force P of the substrate 12 is expressed by the following equation (Equation 10). Can be defined.

以下に前記ディスクパラメーターを考慮した光ディスクについて、具体的な実施例と比較例とにより説明する。

In the following, the optical disk in consideration of the disk parameters will be described with reference to specific examples and comparative examples.

Example 1
In Example 1, as the substrate 12 of the optical disc 1, those made of various PC resins (Young's modulus 2.55 GPa) having different thicknesses as described later were used. Variations in the substrate thickness used were all 1 μm or less.

  A stamper preformat pattern is formed on the PC substrate 12 by thermal nanoimprinting on the substrate 12, a phase change film is sputtered, an overcoat and a hard coat are formed, and then punched into a desired shape (the overcoat after punching). , A hard coat may be formed) to complete the optical disc 1.

  FIG. 4 is an explanatory diagram of a disk evaluation apparatus having the same configuration as the recording / reproducing apparatus of the present embodiment, in which 21 is a drive unit of the spindle motor 4, 22 is a rotation sensor for detecting the number of disk rotations, and 23 is a disk deflection. A deflection amount sensor 24 that detects the amount is a control unit that receives information from the drive unit 21, the rotation sensor 22, the deflection amount sensor 23, and the like and controls the whole.

  In FIG. 4, the optical disk 1 is rotated at a linear velocity of 13 m / s, the stabilizing guide member 7 is approached, the surface vibration of the optical disk 1 is stabilized by air levitation, and the focus / tracking servo is locked to perform recording / reproduction. Do. The tip shape of the stabilizing guide member 7 has a diameter of 20 mm, and the arcuate radius of the tip is 50 mm.

  In the configuration of the first embodiment, the optical disc 1 having a thickness of 50 μm cannot be recorded / reproduced because the surface deflection of the optical disc 1 is not stabilized due to insufficient repulsive force even if the pushing amount of the stabilizing guide member 7 is changed. there were.

  However, as shown in FIG. 6, when the thickness of the optical disc 1 is 70, 90, 120, 160, 600, and 1200 μm, the pushing amount of the stabilizing guide member 7 is optimized based on the disc parameters, respectively. The desired disc repelling force P was obtained, the disc runout was stabilized, and good recording / reproducing characteristics were obtained. As shown in the plan view of FIG. 5 (a) and the front view of FIG. 5 (b), the stabilization guide member 7 is used at three locations (a main stabilization guide member and two sub-stabilization guide members). In the apparatus as well, the disc surface vibration could be stabilized in the same manner, and good recording / reproducing characteristics were obtained.

(Example 2)
A flexible optical disc 1 was produced in the same manner as in Example 1. As the substrate 12, a substrate made of PET resin (Young's modulus 5.3 GPa) was used. When recording / reproduction was performed in the same manner as in Example 1, in the configuration of Example 2, the optical disk 1 having a thickness of 50 μm was not able to repel the disk due to insufficient repulsive force of the optical disk 1 even if the amount of pushing of the stabilizing guide member 7 was changed. The surface runout was not stabilized and recording / reproduction was impossible.

  However, as shown in FIG. 7, when the thickness of the optical disc 1 is 75, 100, 125, 188, 250 μm, the pushing amount of the stabilizing guide member 7 is optimized based on the disc parameters, respectively. Disk repulsive force P was obtained, disk surface vibration was stabilized, and good recording / reproducing characteristics were obtained. In the apparatus using the stabilizing guide member 7 shown in FIGS. 5 (a) and 5 (b) at three locations, the disc surface vibration can be similarly stabilized and good recording / reproducing characteristics can be obtained. It was.

(Example 3)
A flexible optical disc 1 was produced in the same manner as in Example 1. A substrate made of PI resin (Young's modulus 7.2 GPa) was used as the substrate 12. When recording / reproduction was performed in the same manner as in Example 1, as shown in FIG. 8, when the thickness of the optical disk 1 is 50, 100, 75, 125, and 175 μm, the amount of pressing of the stabilizing guide member 7 is By optimizing on the basis of the disk parameters, a desired disk repulsive force P was obtained, disk surface deflection was stabilized, and good recording / reproduction characteristics were obtained. Similarly to the above, even in an apparatus using the stabilizing guide member 7 shown in FIGS. 5A and 5B at three locations, the disc surface runout can be stabilized in the same manner, and good recording / reproduction can be achieved. Characteristics were obtained.

  Specifically, the product P of the rigidity k of the optical disc 1 and the deflection amount W of the optical disc 1 is desirably 0.6 to 2000 mN, and further, the product P is 0.6 to 2000 mN. The thickness t or Young's modulus E of the optical disc 1 (or substrate 12) is set, the material of the optical disc 1 (or substrate 12) is selected, or the thickness t in the circumferential direction of the optical disc 1 (or substrate 12) is selected. It is conceivable that the variation is 10 μm or less.

  Further, in the recording / reproducing apparatus having the configuration shown in FIG. 4, by adjusting the disk parameters and aerodynamically stabilizing the disk surface runout, highly accurate and stable recording / reproducing can be performed. Can do.

  For example, the control unit 24 controls the drive unit 21 based on the detection signal of the deflection amount sensor 23 so that the product P of the rigidity k of the optical disc 1 and the deflection amount W of the optical disc 1 becomes 0.6 to 2000 mN. It is conceivable to control the linear velocity when the optical disk 1 is rotationally driven by controlling the drive unit 21 based on the detection signal of the rotation sensor 22.

  By manufacturing an optical disc and a disc substrate based on the disc parameters, a high-quality flexible optical disc can be obtained.

(Comparative Example 1)
A flexible optical disk was produced in the same manner as in Example 1. However, the substrate made of PC uses a substrate having a thickness of 160 μm, and the relationship between thickness variation and disk runout is shown in FIG.

  As shown in FIG. 9, even when disks having the same thickness are used, if the thickness variation increases, the disk surface runout deteriorates. The thickness variation is superimposed as a fixed surface runout that cannot be removed even if the disk is air-stabilized by the stabilizing guide member. In principle, if a thickness variation of 10 μm exists in the disk, the surface runout of the disk will never be 10 μm or less. In addition, temperature variations, stress variations, and thickness variations such as overcoat and hard coat at the time of forming the recording film are superimposed, and the disc surface deflection further increases. That is, even if the disk has a sufficient aerodynamic force, the disk runout cannot be stabilized.

  As a result, in Comparative Example 1, since the disc surface shake is large, the followability of the focus servo is not good, the focus servo cannot be sufficiently pulled in, and good recording / reproduction characteristics can be obtained due to tracking failure. There wasn't.

(Comparative Example 2)
A flexible optical disk was produced in the same manner as in Example 1. However, the preformat pattern transfer was performed on a molded substrate having a thickness of 1.2 mm made of PC resin by injection molding. If the stabilizing guide member push-in amount is 3 mm or more, the pushing force by the stabilizing guide member is too strong, and if the repulsive force of the disc is generated, the balance between push-in and repulsion will deteriorate, and the disc will rub against the guide strongly. As a result, the aerodynamic stabilization phenomenon did not occur, and the low surface deflection of the disk could not be achieved.

  In Comparative Example 2, as in Comparative Example 1, since the disc surface shake is large, the followability of the focus servo is not good, the focus servo cannot be sufficiently pulled in, or the tracking is poor, and good recording / reproduction characteristics are obtained. Could not get.

  The present invention can be applied to a recording disk utilized in a disk-shaped recording disk such as a phase change memory, a magneto-optical memory, and a hologram memory, and is not limited to an optical disk, but is particularly flexible. It is possible to meet the demand for stabilizing the surface runout of the sheet-like optical disc.

Schematic configuration diagram of an information recording / reproducing apparatus for explaining an embodiment of the present invention Illustration of the basic concept of the present invention and the disk parameters in this embodiment Illustration of disk parameters in this embodiment Explanatory drawing of the disk evaluation apparatus of the structure similar to the recording / reproducing apparatus of this embodiment It is a schematic block diagram of the other information recording / reproducing apparatus which is embodiment of this invention, Comprising: (a) is a top view, (b) is a front view The figure which shows the relationship between the disk repulsion force and disk surface runout in Example 1. The figure which shows the relationship between the disk repulsive force and disk surface runout in Example 2. The figure which shows the relationship between the disk repulsive force and disk surface runout in Example 3 The figure which shows the relationship between disc thickness dispersion | variation and disc surface runout in the comparative example 1

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical disk 4 Spindle motor 5 Optical pick-up 7 Stabilization guide member 11 Disc recording layer 12 Substrate 21 Spindle motor drive part 22 Rotation sensor 23 Deflection sensor 24 Control part

Claims (11)

A surface vibration stabilizing member having an arbitrary shape is brought close to the surface opposite to the recording / reproducing surface of the recording disk having flexibility, and the surface opposite to the surface vibration stabilizing member with respect to the recording disk. In the manufacturing method of the recording disk used in a recording / reproducing apparatus that performs recording / reproduction with the pickup in a state in which a pickup is disposed and surface vibration of the recording disk is reduced,
The rigidity k of the recording disk is defined by the following formula (Equation 1),

(Where E: Young's modulus of the recording disk, b: diameter of the surface runout stabilization member, a: radius of the recording disk pressed against the surface runout stabilization member, t: thickness of the recording disk),
Further, when the surface vibration stabilizing member pushes the recording disk relatively close to the recording disk, the amount of displacement when the position of the surface of the recording disk is displaced is the amount of bending of the recording disk. W is defined, and the product P of the recording disk stiffness k and the deflection amount W of the recording disk is defined as a disk parameter by the following equation (Equation 2).

A recording disk manufacturing method comprising manufacturing a recording disk by adjusting the disk parameters.   2. The recording disk manufacturing method according to claim 1, wherein a product P of a rigidity k of the recording disk and a deflection amount W of the recording disk is 0.6 to 2000 mN.   2. The recording disk according to claim 1, wherein the thickness of the substrate of the recording disk is set so that a product P of a rigidity k of the recording disk and a deflection amount W of the recording disk is 0.6 to 2000 mN. Disc manufacturing method.   2. The Young's modulus of the substrate of the recording disk is set so that a product P of a rigidity k of the recording disk and a deflection amount W of the recording disk is 0.6 to 2000 mN. Recording disk manufacturing method.   2. The recording material according to claim 1, wherein a material of a substrate of the recording disk is selected so that a product P of a rigidity k of the recording disk and a deflection amount W of the recording disk is 0.6 to 2000 mN. Disc manufacturing method.   The thickness variation in the circumferential direction of the substrate of the recording disk is set to 10 μm or less so that the product P of the recording disk stiffness k and the deflection amount W of the recording disk is 0.6 to 2000 mN. The method of manufacturing a recording disk according to claim 1.   A surface vibration stabilizing member having an arbitrary shape is brought close to the surface opposite to the recording / reproducing surface of the recording disk having flexibility, and the surface opposite to the surface vibration stabilizing member with respect to the recording disk. A recording disk for use in a recording / reproducing apparatus that performs recording / reproduction with the pickup in a state in which a pickup is disposed to reduce surface vibration of the recording disk, wherein the recording disk is any one of claims 1 to 6. A recording disk produced by the method for producing a recording disk as described in the above section.   A surface vibration stabilizing member having an arbitrary shape is brought close to the surface opposite to the recording / reproducing surface of the recording disk having flexibility, and the surface opposite to the surface vibration stabilizing member with respect to the recording disk. A disk substrate constituting the recording disk for use in a recording / reproducing apparatus that performs recording / reproduction with the pickup in a state in which a pickup is disposed to reduce surface vibration of the recording disk. A disk substrate comprising the configuration of the recording disk manufacturing method according to any one of? 6. A surface vibration stabilizing member having an arbitrary shape is brought close to the surface opposite to the recording / reproducing surface of the recording disk having flexibility, and the surface opposite to the surface vibration stabilizing member with respect to the recording disk. In a recording / reproducing apparatus that performs recording / reproduction with the pickup in a state in which a pickup is disposed and the surface vibration of the recording disk is reduced,
The rigidity k of the recording disk is defined by the following equation (Equation 3),

(Where E: Young's modulus of the recording disk, b: diameter of the surface runout stabilization member, a: radius of the recording disc at the portion pressed against the surface runout stabilization member, t: thickness of the recording disc),
Further, when the surface vibration stabilizing member pushes the recording disk relatively close to the recording disk, the amount of displacement when the position of the surface of the recording disk is displaced is the amount of bending of the recording disk. W is defined, and the product P of the recording disk stiffness k and the deflection amount W of the recording disk is defined as a disk parameter by the following equation (Equation 4):

A recording / reproducing apparatus which performs recording / reproduction by adjusting the disk parameter and aerodynamically stabilizing the disc surface vibration.   2. The apparatus according to claim 1, further comprising means for controlling the deflection amount W of the recording disk so that a product P of a rigidity k of the recording disk and a deflection amount W of the recording disk is 0.6 to 2000 mN. 9. The recording / reproducing apparatus according to 9.   The recording disk includes a means for controlling a linear velocity during rotation of the recording disk so that a product P of the recording disk rigidity k and the recording disk deflection amount W is 0.6 to 2000 mN. The recording / reproducing apparatus according to claim 9.

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