JP2004110919A - Recording disk driving device, turntable used therefor, and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a turntable capable of suppressing the occurrence of the surface wobbling of a supported recoding disk by increasing the flatness of a disk support surface defined by the support surface of a disk supporting section. <P>SOLUTION: The turntable is provided with a table body 46 rotated in a predetermined direction by a rotary-driving mechanism, and a disk support projection 48 disposed in the table body 46. A plurality of disk support projections 48 are disposed at intervals in a circumferential direction in the table main body 46, and the table body 46 and the disk support projections 48 are integrally formed by molding. On the support surface of the disk support projection 48, a high-friction member 50 is disposed to prevent the slippage of a recording disk 40. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a recording disk drive for rotating a recording disk, a turntable used therefor, and a method of manufacturing a turntable.
[0002]
[Prior art]
2. Description of the Related Art A disk drive is used to rotate a removable recording disk such as a CD-ROM, a DVD-ROM, a DVD-RAM, and an optical disk in a predetermined direction. This disk drive device includes a turntable that supports the recording disk, a clamp member for clamping the recording disk in cooperation with the turntable, and a rotation driving mechanism for rotating the turntable, The turntable and the recording disk are integrally rotated by the rotation drive mechanism. The turntable in this disk drive device includes a table main body rotated by a rotary drive mechanism and a disk support for supporting a recording disk. The disk support is provided in an annular shape, and the recording disk is supported by the annular support surface (for example, see Patent Documents 1 and 2).
[0003]
[Patent Document 1]
JP 2000-339837 A [Patent Document 2]
JP 2000-339921 A
[Problems to be solved by the invention]
In recent years, from the viewpoint of increasing the density of information recorded on a recording disk and increasing the rotation speed thereof, it has been required to increase the flatness of the support surface of the disk support portion of the turntable, and the runout of the support surface has been required. Is about 30 μm or less when the recording disk is a DVD, about 20 μm or less when the recording disk is a DVD-ROM, and about 10 μm or less when the recording disk is a DVD-RAM. When the runout of the turntable exceeds the above-mentioned allowable range, the runout of the recording disk supported by the disk support part also increases, and the distance between the recording surface of the recording disk and the optical head greatly changes, and the recorded information is correctly read. Writing and / or reading cannot be performed, and a writing and / or reading error occurs.
[0005]
In a conventional turntable, a disk support portion for supporting a recording disk is provided in an annular shape, and its support surface is formed in an annular shape. When the support surface is annular as described above, it is necessary to increase the flatness over a relatively wide range of environment in order to suppress the surface run-out, which makes the production difficult and increases the production cost. For example, when a turntable is formed by molding, it is necessary to increase the flatness of a portion of a mold corresponding to the support surface of the disk support, and high precision processing of a molded product (particularly, the disk support). Required.
[0006]
SUMMARY OF THE INVENTION An object of the present invention is to provide a turntable capable of increasing the flatness of a disk support surface defined by a support surface of a disk support portion, thereby suppressing the occurrence of surface runout of a recording disk to be supported. .
[0007]
Another object of the present invention is to provide a recording disk drive capable of suppressing the surface deflection of the recording disk that occurs during rotation.
Still another object of the present invention is to provide a method of manufacturing a turntable that can relatively easily and inexpensively manufacture a turntable having a disk support surface with high flatness.
[0008]
[Means for Solving the Problems]
The present invention provides a turntable including a table main body that is rotated in a predetermined direction by a rotation drive mechanism, and a disk support protrusion provided on the table main body.
A plurality of the disk support protrusions are provided on the table body at intervals in the circumferential direction, the table body and the disk support protrusions are integrally formed by molding, and a support surface of the disk support protrusions includes: A high friction member for preventing slippage of the recording disk is provided.
[0009]
According to the present invention, since a plurality of disk supporting projections are integrally provided on the table body, in order to reduce the surface runout of the recording disk, the heights of the disk supporting projections are made equal and the supporting surfaces are made equal. Therefore, there is less area to be processed with high precision compared to the conventional case where the disk support portion is provided in an annular shape, and a turntable having a support surface with high flatness is relatively easy. And can be manufactured at low cost. In addition, since the high friction member is provided on the support surface of each disk support projection, the frictional resistance between the recording disk and the disk support can be increased, and the recording disk can be reliably supported.
[0010]
Further, in the present invention, three or four disk support projections are provided on the table main body at intervals in the circumferential direction.
According to the present invention, since three or four disk supporting projections are provided at intervals in the circumferential direction, the recording disk can be reliably supported. In addition, since the number of disk support projections is small, the area to be processed with high precision is small, and it can be manufactured relatively easily and inexpensively.
[0011]
Further, in the present invention, the table body and the disk support protrusion are integrally formed by injection molding of a synthetic resin.
According to the present invention, since the table body and the disk supporting projection are formed by injection molding of a synthetic resin, they can be manufactured easily and at low cost.
[0012]
Further, in the present invention, a turntable according to any one of claims 1 to 3, a clamp member for clamping a recording disk in cooperation with the turntable, and rotating the turntable in a predetermined direction. And a rotation drive mechanism for
[0013]
According to the present invention, since the above-described turntable is provided, the recording disk can be supported in a flat state by the disk supporting projection, and the occurrence of surface runout during rotation can be suppressed.
[0014]
The present invention also provides a table main body that is rotated in a predetermined direction by a rotation drive mechanism, and a plurality of disk supporting protrusions provided on the table main body at circumferential intervals to support a recording disk. In a manufacturing method for manufacturing a turntable provided with,
First and second molds that cooperate with each other to define an injection molding space for the table body and the plurality of disk support protrusions, and corresponding to each of the plurality of disk support protrusions; And a plurality of adjustment pins attached to the first or second mold so as to be position-adjustable, and each of the plurality of adjustment pins supports a corresponding disk support projection. The height of the corresponding disk support projection is set by defining a surface and adjusting the position of each adjustment pin.
[0015]
According to the present invention, when manufacturing a turntable, first and second dies that define an injection molding space are used, and a plurality of dies can be adjusted in position on the first dies (or the second dies). Adjustment pins are attached. Each adjustment pin is configured to define a corresponding disk support surface, and by adjusting the position of the adjustment pin, the height of the disk support projection of the turntable to be injection molded can be set. Therefore, by processing the flatness of the end face of each adjustment pin with high precision, the flatness of the support surface of the disk support portion after the injection molding can be increased, and by adjusting the position thereof, the post-injection molding can be performed. The height of the disk support projection can be made a predetermined height, and a turntable with less surface runout can be manufactured relatively easily and at low cost. During the injection molding, the first and second molds may be moved together, or the second mold may be fixed and the first mold may be moved with respect to the second mold. Is also good.
[0016]
In the present invention, the first mold is attached to a first member, the second mold is attached to a second member, and each of the plurality of adjustment pins is attached to the first mold. The position of each adjustment pin with respect to the first mold is adjusted by interposing an adjustment spacer between each of the plurality of adjustment pins and the first member.
[0017]
According to the present invention, the first mold is attached to the first member, and the plurality of adjustment pins are attached to the first mold so as to be adjustable in position. An adjustment spacer is used for adjusting each adjustment pin, and the position of the adjustment pin with respect to the first mold can be easily adjusted by interposing the adjustment spacer between the adjustment pin and the first member.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings. First, a recording disk drive and a turntable used therein will be described with reference to FIGS. FIG. 1 is a sectional view showing a main part of the recording disk drive, and FIG. 2 is a perspective view showing a turntable of the recording disk drive of FIG.
[0019]
In FIG. 1, the illustrated recording disk drive includes a spindle motor 2 as a rotation drive mechanism. The spindle motor 2 includes a support housing 4 including a circuit board and a rotor 6 rotatable with respect to the support housing 4. The rotor 6 is supported by the support housing 4 via bearing means 8. ing.
[0020]
The bearing housing 10 is mounted on the support housing 4 by caulking or the like, and the bottom of the bearing housing 10 is closed. The bearing means 8 includes a sleeve-shaped radial bearing 12 and a plate-shaped thrust bearing 14. The radial bearing 12 is mounted on the inner peripheral side of the bearing housing 10, and the thrust bearing 14 is mounted on the bottom of the bearing housing 10. I have.
[0021]
The rotor 6 includes a cup-shaped rotor body 16 and a rotating shaft 20 mounted on an end wall portion 18 of the rotor body 16. The rotating shaft 20 is received in the bearing housing 10, and the shaft portion is Further, an arcuate end face 24 at one end (an end face formed in an arc shape and a lower end face in FIG. 1) is rotatably supported by the thrust bearing 14. An annular recess 26 is provided at one end of the rotating shaft 20, and a retaining ring 28 is mounted near the bottom of the bearing housing 10, and an inner peripheral portion of the retaining ring 28 is attached to the annular recess 26 of the rotating shaft 20. The stopper ring 28 prevents the rotation shaft 20 (and the rotor body 16 mounted on the rotation shaft 20 and the like) from coming off.
[0022]
An annular rotor magnet 32 is mounted on the inner peripheral surface of the peripheral side wall 30 of the rotor body 16. Further, a stator 34 is disposed facing the rotor magnet 32, and the stator 34 is composed of a stator core 36 mounted on the outer peripheral surface of the bearing housing 10 and a coil 38 wound around the stator core 36. . Therefore, when a drive current flows through the coil 38 as required, the stator core 36 is magnetized, and the rotor 6 is rotationally driven in a predetermined direction by the mutual magnetic action between the stator core 36 and the rotor magnet 32.
[0023]
The spindle motor 2 is used to rotationally drive a removable recording disk 40 such as a CD-ROM, a DVD-ROM, a DVD-RAM, and an optical disk. In this embodiment, the other end (the upper end in FIG. 1) of the rotating shaft 20 projects beyond the end wall 18 of the rotor body 16 toward the other end (the upper side in FIG. 1). At the end, a turntable 42 and a suction means 44 are mounted.
[0024]
The turntable 42 will be described with reference to FIG. 2 as well. The illustrated turntable 42 includes a disk-shaped table main body 46, and is provided on the surface (the upper surface in FIGS. 1 and 2) of the table main body 46 in the circumferential direction. Four disk support projections 48 (three in FIG. 2) are provided at intervals. Each disk support projection 48 is substantially the same size and is formed in a short cylindrical shape. A high friction member 50 made of a material having a large coefficient of friction, for example, synthetic rubber, is provided on the support surface (the upper surface in FIGS. 1 and 2) of each disk support projection 48. Such a high friction member 50 can be provided by sticking with an adhesive, spray coating, or the like. The recording disk 40 is supported on the support surfaces of these disk support protrusions 48 (disk support surfaces defined by these support surfaces) via the high friction member 50, and thus, four or three disk support members are provided. By supporting the recording disk 40 with the projection 48, the recording disk 40 can be reliably supported.
[0025]
At the center of the turntable 42, there is provided a guide positioning protrusion 52 projecting substantially hemispherically toward the other end side (upward in FIG. 1), and an accommodation recess 54 is provided at the center of the guide positioning protrusion 52. The suction means 44 provided and attached to the protruding end of the rotating shaft 20 is housed in the housing recess 54. The suction means 44 includes a support plate 56 mounted on the rotating shaft 20 and an annular permanent magnet 58 mounted on the surface of the support plate 56.
[0026]
Above the turntable 42, a clamp member 60 is provided so as to be movable between a clamp position indicated by a two-dot chain line in FIG. 1 and a retracted position (not shown) retracted from the clamp position. The clamp member 60 has an annular pressing portion 62 on an outer peripheral portion thereof, and the recording disk 40 is clamped between the annular pressing portion 62 and the plurality of disk supporting protrusions 48 of the turntable 42.
[0027]
The mounting of the recording disk 40 on the turntable 42 is performed as follows. When the clamp member 60 is in the retracted position, the recording disk 40 is fitted onto the guide positioning projection 52 of the turntable 40 from above in FIG. When mounted in this manner, the inner peripheral portion (the portion defining the mounting hole) of the recording disk 40 is guided along the peripheral surface of the guide positioning protrusion 52, and is concentric with the rotation shaft 20 by the guide positioning protrusion 52. And is supported by the support surfaces of the plurality of disk support protrusions 48. Thereafter, the clamp member 60 is positioned from the retracted position to a clamp position shown by a two-dot chain line in FIG. 1, and the clamp member 60 is magnetically attracted to the permanent magnet 58 of the attracting means 44, so that the pressing portion of the clamp member 60 is pressed. 62 presses the inner peripheral portion of the recording disk 40, and the recording disk 40 is thus clamped between the turntable 42 and the clamp member 60. When the spindle motor 2 is driven to rotate, the recording disk 40 is driven to rotate in a predetermined direction while being clamped.
[0028]
In order to suppress the runout of the recording disk 40 during rotation, the heights of the plurality of disk support projections 48 of the turntable 40 are made substantially equal, and the flatness of the support surface of each disk support projection 48 is reduced. It is important to increase the height, for example, the following makes it relatively easy and inexpensive to manufacture.
[0029]
In order to manufacture such a turntable 40, it is desirable to form the turntable 40 by injection molding with a synthetic resin. As the synthetic resin, an engineered plastic having heat resistance, particularly one having a low coefficient of thermal expansion and excellent dimensional stability. For example, polycarbonate (PC) resin reinforced with glass fiber is preferable. The content of glass fibers in such a resin is in the range of 10 to 40% by weight, more preferably 25 to 35% by weight. Instead of polycarbonate, a mixture of a thermoplastic resin such as polybutylene terephthalate (PBT), polyethylene terephthalate (PET), or polyoxymethylene (POM) with a reinforcing material such as glass fiber or carbon fiber may be used. .
[0030]
At the time of injection molding, injection molding can be performed as shown in FIG. 5 using the mold shown in FIGS. In FIGS. 3 and 4, the illustrated mold body 72 includes first and second molds 74 and 76. In this embodiment, the second mold 76 is fixed. On the other hand, the first mold 74 is moved in the directions shown by arrows 78 and 80. The first mold 74 is attached to the first mold attaching member 82, and the first mold attaching member 82 is attached to the first member 84. The first member 84 (along with the first mold attaching member 82 and the first One mold 74) is movably ejected between a molding position shown in FIGS. 3, 5A and 5B and a retracted position shown in FIG. 5C retracted from the molding position. It is attached to a molding device main body (not shown). The second mold 76 is attached to a second mold attachment member 86, and the second mold attachment member 86 is attached to a second member (not shown). The mold attachment member 86 and the second mold 7) are fixedly attached to an injection molding apparatus main body (not shown). It should be noted that the second mold attaching member 86 may also function as a second member, and the second mold attaching member 86 may be directly attached to the main body of the injection molding apparatus.
[0031]
As shown in FIGS. 3, 5 (a) and 5 (b), the first and second molds 74 and 76 cooperate with each other to form the table body 46, the disk support projection 48 and the guide positioning projection. An injection molding space 88 for the part 52 is defined, and in this connection, a molten resin flow path 90 is formed in the second mold 76 and the second mold attaching member 86 so that the molten molding resin is formed. Is supplied to the injection molding space 88 through the molten resin flow path 90. Further, a pair of projecting pins 87 are movably attached through the first mold 74, the first mold attaching member 82, and the first member 84, and the pair of projecting pins 87 are projected toward the second mold 76. Then, the formed turntable 42 is detached from the first mold 74 as described later.
[0032]
In this embodiment, in order to enable the height of the disk support projection 48 to be adjusted, a first mold 74 that defines the surface side of the turntable 42 (the side on which the disk support projection 48 is provided) is provided. Adjustment pins 92 are provided so as to be position-adjustable corresponding to the respective disk support projections 48. The first mold 74 and the first mold mounting member 82 are provided with mounting holes penetrating therethrough and communicating with the injection molding space 88, and the adjusting pins 92 are accommodated in the mounting holes so as to be position-adjustable. . The tip surface of each adjustment pin 92 defines a support surface of the disk support projection 48. In this embodiment, the mounting hole is formed in a circular cross section, and each adjustment pin 92 has a circular cross section corresponding to the mounting hole shape. With this configuration, the short cylindrical disk support projection 48 is integrally formed with the table body 46 and the guide positioning projection 52 by injection molding.
[0033]
As shown in FIG. 4, the position adjustment of the adjustment pin 92 is performed by interposing an adjustment spacer 94 between the rear end of the adjustment pin 92 and the first member 84. For example, the adjustment spacer 94 having a predetermined thickness is provided. Is performed by interposing one or a plurality of adjustment spacers 94, or by interposing one or more adjustment spacers 94 having different thicknesses. In the example shown in FIG. Are interposed. When the thickness of the interposed adjusting spacer 94 becomes thicker (or thinner), the adjusting pin 92 moves in a direction approaching (or away from) the second mold 86, and therefore, the height of the formed disk support projection 48 is increased. By adjusting the positions of the plurality of adjustment pins 92 as required, the height of the plurality of disk support projections 48 after molding is substantially reduced. Can be equal. Also, by increasing the flatness of the distal end surface of the adjustment pin 92 (the surface that defines the support surface of the disk support projection 48), the flatness of the support surface of the molded disk support projection 48 can be increased. By making these heights equal and increasing the flatness, the recording disk 40 can be supported in a flat shape, thereby preventing the recording disk 40 from oscillating during rotation. In particular, as in this embodiment, since the support surface of the disk support projection 48 is defined by the plurality of adjustment pins 92, the flatness of only the tip surfaces of these adjustment pins 92 may be increased, and these support surfaces may be formed. The area is smaller than in the past, the processing is easier, and the cost of the mold can be reduced.
[0034]
The molding using the above-described mold body 72 is performed, for example, as shown in FIG. To explain with reference to FIGS. 5A to 5C, first, as shown in FIG. 5A, the first member 84 is moved in the direction indicated by the arrow 78 and positioned at the molding position. When moved, the first mold 74 and the second mold 76 are clamped as required, and these molds 74 and 76 define an injection molding space 88 (mold clamping step).
[0035]
After the mold clamping, as shown in FIG. 5B, the molten resin is fed into the injection molding space 88 through the molten resin flow path 90 as indicated by an arrow (injection step). Then, while being supplied to the injection molding space 88, it is maintained at a predetermined pressure state (pressure keeping step), and cooled as required (cooling step).
[0036]
After that, the first member 84 is moved toward the retracted position in the direction indicated by the arrow 80, and the first mold 74 separates from the second mold 76 (release process). At the time of this release, the protruding pin 87 protrudes toward the second mold 76, and the formed turntable 42 is taken out of the first mold 74 by the protruding pin 87. In this manner, the turntable 42 is Injection molded.
[0037]
While the embodiments of the recording disk drive and the turntable (turntable manufacturing method) used in the present invention have been described above, the present invention is not limited to such an embodiment and departs from the scope of the present invention. Various changes and modifications can be made without doing so.
[0038]
For example, in the molding method of the above-described embodiment, the adjustment pins 92 are provided on the first mold 74, but instead of such a configuration, the adjustment pins may be provided on the second mold. In this case, the second mold 76 defines the front side of the turntable 42).
[0039]
Further, for example, in the above-described embodiment, the shape of the disk support projection 48 of the turntable 42 is formed in a short cylindrical shape, but the shape is not limited to such a shape, and may be a short square pillar, a short hexagonal pillar, or the like. It can also be formed in another polygonal column shape.
[0040]
【The invention's effect】
According to the turntable of the first aspect of the present invention, since a plurality of disk support portions are integrally provided on the table body, a turntable having a support surface with high flatness can be manufactured relatively easily and at low cost. Can be. Further, since the high friction member is provided on the support surface of each disk support portion, the recording disk can be reliably supported.
[0041]
Further, according to the turntable of the second aspect of the present invention, since three or four disk supporting portions are provided at intervals in the circumferential direction, the recording disk can be reliably supported. In addition, since the number of disk support portions is small, it can be manufactured relatively easily and at low cost.
[0042]
Further, according to the turntable of the third aspect of the present invention, since the table main body and the disk supporting projection are formed by injection molding of synthetic resin, it can be manufactured easily and inexpensively.
[0043]
According to the recording disk drive of the fourth aspect of the present invention, the recording disk can be supported in a flat state by the disk supporting portion, and the occurrence of surface runout during rotation can be suppressed.
[0044]
According to the turntable manufacturing method of the fifth aspect of the present invention, since the adjustment pin that defines the disk support projection is provided so as to be position-adjustable, the position of the adjustment pin is adjusted so that injection can be performed. The height of the disk support portion of the turntable to be formed can be set, and a turntable with less surface runout can be manufactured relatively easily and at low cost.
[0045]
According to the turntable manufacturing method of the sixth aspect of the present invention, the position of the adjustment pin with respect to the first mold can be easily adjusted by interposing the adjustment spacer between the adjustment pin and the first member. Can be.
[Brief description of the drawings]
FIG. 1 is a sectional view showing a main part of an embodiment of a recording disk drive according to the present invention.
FIG. 2 is a perspective view showing a turntable of the recording disk drive of FIG.
FIG. 3 is a cross-sectional view showing a mold used when injection molding a turntable.
FIG. 4 is a sectional view for explaining one adjustment of an adjustment pin in the mold body of FIG. 3;
FIGS. 5A to 5C are cross-sectional views illustrating steps of injection molding of a turntable.
[Explanation of symbols]
2 Spindle motor 6 Rotor 20 Rotary shaft 40 Recording disk 42 Turntable 44 Suction means 46 Table body 48 Disk support protrusion 50 High friction member 60 Clamp member 74 First mold 76 Second mold 84 First member 87 Projection pin 88 Injection molding space 90 Molten resin flow path 92 Adjusting pin

Claims (6)

In a turntable including a table main body that is rotated in a predetermined direction by a rotation drive mechanism and a disk support projection provided on the table main body,
A plurality of the disk support protrusions are provided on the table body at intervals in the circumferential direction, the table body and the disk support protrusions are integrally formed by molding, and a support surface of the disk support protrusions includes: A turntable provided with a high friction member for preventing a recording disk from slipping. The turntable according to claim 1, wherein three or four disk support protrusions are provided on the table main body at intervals in a circumferential direction. 3. The turntable according to claim 1, wherein the table main body and the disk support protrusion are integrally formed by injection molding of a synthetic resin. A turntable according to any one of claims 1 to 3, a clamp member for clamping a recording disk in cooperation with the turntable, and a rotation drive mechanism for rotating the turntable in a predetermined direction. , A recording disk drive. Manufactures a turntable including a table main body that is rotated in a predetermined direction by a rotation drive mechanism, and a plurality of disk support protrusions provided on the table main body at circumferential intervals to support a recording disk. Manufacturing method,
First and second molds that cooperate with each other to define an injection molding space for the table body and the plurality of disk support protrusions, and corresponding to each of the plurality of disk support protrusions; And a plurality of adjustment pins attached to the first or second mold so as to be position-adjustable, and each of the plurality of adjustment pins supports a corresponding disk support projection. A method for manufacturing a turntable, comprising defining a surface and adjusting the position of each adjustment pin to set the height of a corresponding disk support projection. The first mold is attached to a first member, the second mold is attached to a second member, and each of the plurality of adjustment pins is position-adjustable with respect to the first mold. 6. The turntable according to claim 5, wherein a position of each of the adjustment pins with respect to the first mold is adjusted by being attached and interposing an adjustment spacer between each of the plurality of adjustment pins and the first member. Manufacturing method.

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