JP4035409B2 - RECORDING DISK DRIVE DEVICE, TURN TABLE USED FOR THE SAME, AND MANUFACTURING METHOD THEREOF - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a recording disk drive apparatus for rotationally driving a recording disk, a turntable used therefor, and a method for manufacturing the turntable.
[0002]
[Prior art]
A disk drive device is used to rotationally drive a detachable recording disk such as a CD-ROM, DVD-ROM, DVD-RAM, or optical disk in a predetermined direction. The disk drive device includes a turntable that supports the recording disk, a clamp member that clamps the recording disk in cooperation with the turntable, and a rotational drive mechanism that rotationally drives the turntable. The turntable and the recording disk are integrally rotated by the rotation drive mechanism. The turntable in the disk drive device includes a table main body rotated by a rotation drive mechanism and a disk support portion that supports the recording disk. The disk support portion is provided in an annular shape, and the recording disk is supported by the annular support surface (see, for example, Patent Document 1 and Patent Document 2).
[0003]
[Patent Document 1]
JP 2000-339837 A [Patent Document 2]
Japanese Patent Laid-Open No. 2000-339921
[Problems to be solved by the invention]
In recent years, from the viewpoint of increasing the density of recorded information on a recording disk and increasing the rotational speed thereof, it has been required to increase the flatness of the support surface of the disk support portion of the turntable. 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. If the surface deflection of the turntable exceeds the allowable range described above, the surface deflection of the recording disk supported by the disk support section also increases, and the distance between the recording surface of the recording disk and the optical head changes greatly, so that the recorded information is correct. 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 the support surface is formed in an annular shape. If the support surface is annular in this way, it is necessary to increase the flatness over a relatively wide range of environment in order to suppress the surface runout, making it difficult to manufacture and increasing the manufacturing cost. For example, when the turntable is formed by molding, it is necessary to increase the flatness of the portion of the mold corresponding to the support surface of the disc support portion, and the processing of the molded product (particularly the disc support portion) is also highly accurate. Required.
[0006]
An object of the present invention is to provide a turntable capable of increasing the flatness of a disk support surface defined by the support surface of a disk support portion and thereby suppressing the occurrence of surface deflection of a recording disk to be supported. .
[0007]
Another object of the present invention is to provide a recording disk drive device capable of suppressing the surface shake of the recording disk that occurs during rotation.
Still another object of the present invention is to provide a turntable manufacturing method that can manufacture a turntable having a disk support surface with high flatness relatively easily and inexpensively.
[0008]
[Means for Solving the Problems]
The present invention, in a turntable comprising a table body rotated in a predetermined direction by a rotational drive mechanism, and a disk support protrusion provided on the table body,
A plurality of the disk support protrusions are provided in the table main body at intervals in the circumferential direction, and the table main body and the disk support protrusion are integrally formed by molding, and the support surface of the disk support protrusion is A high friction member for preventing the recording disk from slipping is provided.
[0009]
According to the present invention, since the disk supporting projection is provided integrally with a plurality the table body, together with in order to reduce the surface runout of the recording disk is equal to the height of the disc supporting projection, which support The flatness of the surface may be increased. Therefore, the area to be processed with high accuracy is small as compared with the conventional case where the disk support portion is provided in an annular shape, and a turntable having a high flatness support surface is relatively It can be manufactured easily and inexpensively. In addition, since the high friction member is provided on the support surface of each disk support protrusion, the frictional resistance between the recording disk and the disk support can be increased, and the recording disk can be reliably supported.
[0010]
In the present invention, three or four disk support protrusions are provided on the table body at intervals in the circumferential direction.
According to the present invention, three or four disk support protrusions are provided at intervals in the circumferential direction, so that the recording disk can be reliably supported. In addition, since the number of the disk support protrusions is small, the area to be processed with high accuracy is small, and it can be manufactured relatively easily and inexpensively.
[0011]
In the present invention, the table main body and the disk support protrusion are integrally formed by injection molding of synthetic resin.
According to the present invention, since the table main body and the disk support protrusion are formed by injection molding of synthetic resin, they can be manufactured easily and inexpensively.
[0012]
In the present invention, the turntable, a clamp member for sandwiching a recording disk in cooperation with the turntable, and a rotation drive mechanism for rotationally driving the turntable in a predetermined direction are provided. It is characterized by that.
[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 support protrusion, and occurrence of surface runout during rotation can be suppressed.
[0014]
The present invention also includes a table main body that is rotated in a predetermined direction by a rotary drive mechanism, and a plurality of disk support protrusions that are provided on the table main body at intervals in the circumferential direction and support a recording disk. In a manufacturing method for manufacturing a provided turntable,
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 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 protrusion. By defining the surface and adjusting the position of each adjustment pin, the height of the corresponding disk support protrusion is set.
[0015]
According to the present invention, when the turntable is manufactured, the first and second molds that define the injection molding space are used, and a plurality of the first mold (or the second mold) can be adjusted in position. An adjustment pin is attached. Each adjustment pin is configured to define a corresponding disk support surface. By adjusting the position of the adjustment pin, the height of the disk support protrusion 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 accuracy, the flatness of the support surface of the disk support portion after injection molding can be increased, and by adjusting the position, The height of the disc support protrusion can be set to a predetermined height, and a turntable with little surface runout can be manufactured relatively easily and inexpensively. During the injection molding, the first and second molds may be moved together, or the second mold is fixed and the first mold is moved with respect to the second mold. Also good.
[0016]
In the present invention, the first mold is attached to the first member, the second mold is attached to the 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 attaching 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 position-adjustable. An adjustment spacer is used to adjust 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]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, it will be described in more detail with reference to the accompanying drawings. First, with reference to FIG. 1 and FIG. 2, a recording disk drive device and a turntable used therefor will be described. FIG. 1 is a cross-sectional view showing a main part of the recording disk drive device, and FIG. 2 is a perspective view showing a turntable of the recording disk drive device of FIG.
[0019]
In FIG. 1, the illustrated recording disk drive device includes a spindle motor 2 as a rotational drive mechanism. The spindle motor 2 includes a support housing 4 composed of a circuit board and the like, and a rotor 6 that is rotatable with respect to the support housing 4. The rotor 6 is supported by the support housing 4 via bearing means 8. ing.
[0020]
A bearing housing 10 is mounted on the support housing 4 by means such as caulking, 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. Yes.
[0021]
The rotor 6 includes a cup-shaped rotor body 16 and a rotating shaft 20 attached to 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 a radial bearing 12. In addition, an arc-shaped end surface 24 (one end surface formed in an arc shape, which is the lower end surface in FIG. 1) at one end thereof 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 in the vicinity of the bottom of the bearing housing 10, and the inner periphery of the retaining ring 28 is the annular recessed portion 26 of the rotating shaft 20. The retaining ring 28 prevents the rotary shaft 20 (and the rotor main body 16 attached thereto) 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. A stator 34 is disposed to face the rotor magnet 32, and the stator 34 includes 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. . Accordingly, 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 detachable recording disk 40 such as a CD-ROM, DVD-ROM, DVD-RAM, or optical disk. In this embodiment, the other end portion (the upper end portion in FIG. 1) of the rotating shaft 20 protrudes beyond the end wall portion 18 of the rotor body 16 to the other end side (upward in FIG. 1). A turntable 42 and suction means 44 are attached to the ends.
[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 the surface of the table main body 46 (upper surface in FIGS. 1 and 2) has a circumferential direction. Four disk support protrusions 48 (three are shown in FIG. 2) are provided at intervals. Each disk support protrusion 48 has 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, such as synthetic rubber, is provided on the support surface (the upper surface in FIGS. 1 and 2) of each disk support protrusion 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 the disk support protrusions 48 (disk support surfaces defined by these support surfaces) via the high friction member 50, and thus the four or three disk supports are supported. By supporting the protrusion 48, the recording disk 40 can be reliably supported.
[0025]
A guide positioning protrusion 52 that protrudes in a substantially hemispherical shape toward the other end side (upward in FIG. 1) is provided at the center of the turntable 42, and an accommodation recess 54 is formed at the center of the guide positioning protrusion 52. The suction means 44 that is provided and attached to the protruding end of the rotating shaft 20 is accommodated in the accommodating recess 54. The suction means 44 includes a support plate 56 attached to the rotary shaft 20 and an annular permanent magnet 58 attached to the surface side of the support plate 56.
[0026]
A clamp member 60 is provided above the turntable 42 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 the outer periphery thereof, and the recording disk 40 is clamped between the annular pressing portion 62 and the plurality of disk support protrusions 48 of the turntable 42.
[0027]
The recording disk 40 is attached to the turntable 42 as follows. In a state where the clamp member 60 is in the retracted position, the recording disk 40 is fitted onto the guide positioning protrusion 52 of the turntable 40 from above in FIG. When mounted in this manner, the inner peripheral portion of the recording disk 40 (portion defining the mounting hole) is guided along the peripheral surface of the guide positioning projection 52, and is concentric with the rotary shaft 20 by the guide positioning projection 52. And are 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 the clamp position indicated 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, thereby pressing the clamp member 60. 62 presses the inner periphery of the recording disk 40, and the recording disk 40 is thus clamped between the turntable 42 and the clamp member 60. Then, when the spindle motor 2 is rotationally driven, the recording disk 40 is rotationally driven in a predetermined direction in a clamped state.
[0028]
In order to suppress the runout of the recording disk 40 during rotation, the heights of the plurality of disk support protrusions 48 of the turntable 40 are made substantially equal, and the flatness of the support surface of each disk support protrusion 48 is set. It is important to make the height higher. For example, it can be manufactured relatively easily and inexpensively by the following.
[0029]
In order to manufacture such a turntable 40, it is desirable to form it by injection molding with a synthetic resin. As the synthetic resin, an engineer plastic having heat resistance, particularly a material having a low coefficient of thermal expansion and excellent dimensional stability. For example, a polycarbonate (PC) resin reinforced with glass fiber is preferable. The glass fiber content in such a resin is 10 to 40% by weight, more preferably 25 to 35% by weight. Instead of polycarbonate, a thermoplastic resin such as polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyoxymethylene (POM), or the like and a reinforcing material such as glass fiber or carbon fiber may be used. .
[0030]
In the injection molding, the mold body shown in FIGS. 3 and 4 can be used for injection molding as shown in FIG. 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, and the second mold 76 is attached to the second mold 76. In contrast, the first mold 74 is moved in the directions indicated by arrows 78 and 80. The first mold 74 is attached to the first mold attachment member 82, the first mold attachment member 82 is attached to the first member 84, and the first member 84 (with the first mold attachment member 82 and the first mold attachment member 82). 1 mold 74) is slidably injected between the molding position shown in FIG. 3, FIG. 5 (a) and FIG. 5 (b) and the retracted position shown in FIG. 5 (c) retracted from this molding position. It is attached to a molding apparatus main body (not shown). The second mold 76 is attached to a second mold attachment member 86, the second mold attachment member 86 is attached to a second member (not shown), and the second member 84 (with this second mold). The mold attaching member 86 and the second mold 7) are fixedly attached to an injection molding apparatus main body (not shown). Note that the second mold attachment member 86 may also function as the second member, and the second mold attachment member 86 may be directly attached to the injection molding apparatus main body.
[0031]
As shown in FIGS. 3, 5 (a) and 5 (b), the first and second molds 74, 76 cooperate with each other so that the table body 46, the disk support protrusion 48, and the guide positioning protrusion An injection molding space 88 for the portion 52 is defined, and in this connection, a molten resin flow path 90 is formed in the second mold 76 and the second mold mounting member 86, and the molding resin is melted. Is fed to the injection molding space 88 through the molten resin flow path 90. A pair of protruding pins 87 are movably mounted through the first mold 74, the first mold mounting member 82, and the first member 84, and the pair of protruding pins 87 are protruded toward the second mold 76. The molded turntable 42 is detached from the first mold 74 as described later.
[0032]
In this embodiment, in order to make the height of the disk support protrusion 48 adjustable, the first mold 74 that defines the surface side of the turntable 42 (the side on which the disk support protrusion 48 is provided) Corresponding to each disk support protrusion 48, an adjustment pin 92 is provided so that the position can be adjusted. The first die 74 and the first die attachment member 82 are provided with attachment holes that pass through them and communicate with the injection molding space 88, and the adjustment pins 92 are accommodated in the attachment holes so that the positions thereof can be adjusted. . The tip surface of each adjustment pin 92 defines the support surface of the disk support protrusion 48. In this embodiment, the attachment hole is formed in a circular cross section, and each adjustment pin 92 has a circular cross section corresponding to the shape of the attachment hole. With this configuration, the short cylindrical disk support protrusion 48 is integrally injection-molded together with the table main body 46 and the guide positioning protrusion 52.
[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 portion of the adjustment pin 92 and the first member 84. For example, the adjustment spacer 94 having a predetermined thickness is provided. 4 or by interposing one or more adjustment spacers 94 having different thicknesses. In the example shown in FIG. 4, three adjustment spacers 94 having the same thickness are provided. A sheet is interposed. When the thickness of the adjusting spacer 94 to be interposed becomes thick (or thin), the adjusting pin 92 moves in the direction approaching (or moving away from) the second mold 86, and therefore, the height of the disk support protrusion 48 after molding is increased. By adjusting the positions of the plurality of adjustment pins 92 as required in this manner, the height of the plurality of disc support protrusions 48 after molding is substantially increased. Can be equal. Further, by increasing the flatness of the tip surface of the adjustment pin 92 (the surface defining the support surface of the disk support protrusion 48), the flatness of the support surface of the disk support protrusion 48 after molding can be increased. By making these heights equal and increasing the flatness, it is possible to support the recording disk 40 in a flat shape, thereby preventing surface vibration of the recording disk 40 during rotation. In particular, as in this embodiment, the support surfaces of the disk support protrusions 48 are defined by a plurality of adjustment pins 92, so that the flatness of only the tip surfaces of these adjustment pins 92 may be increased. The area is smaller than that of the conventional one, the processing becomes easy, and the cost of the mold can be reduced.
[0034]
The molding using the mold body 72 described above is performed, for example, as shown in FIG. Referring 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 to be positioned at the molding position. Thus, the first mold 74 and the second mold 76 are clamped as required, and the molds 74 and 76 define an injection molding space 88 (a mold clamping step).
[0035]
After the mold clamping, as shown in FIG. 5B, the molten resin is fed into the injection molding space 88 as indicated by an arrow through the molten resin flow path 90 (injection process). And it hold | maintains to a predetermined pressure state in the state supplied to the injection molding space 88 (pressure-holding process), and cools as required (cooling process).
[0036]
Thereafter, the first member 84 is moved toward the retracted position in the direction indicated by the arrow 80, and the first mold 74 is separated from the second mold 76 (mold release step). When the mold is released, the protruding pin 87 protrudes toward the second mold 76, and the molded turntable 42 is taken out from the first mold 74 by the protruding pin 87, and the turntable 42 is thus removed. Injection molded.
[0037]
The embodiments of the recording disk drive device according to the present invention and the turntable used in the recording disk drive device have been described above, but the present invention is not limited to such embodiments and departs from the scope of the present invention. Various modifications or corrections can be made without this.
[0038]
For example, in the molding method of the above-described embodiment, the adjustment pin 92 is provided in the first mold 74, but instead of such a configuration, the adjustment pin may be provided in the second mold (this In this case, the second mold 76 defines the surface side of the turntable 42).
[0039]
Further, for example, in the above-described embodiment, the shape of the disk support protrusion 48 of the turntable 42 is formed in a short cylindrical shape. However, the shape is not limited to such a shape, and a short rectangular column shape, a short hexagonal column shape, or the like is used. It can also be formed in other polygonal column shapes.
[00 40]
【The invention's effect】
According to the turntable manufacturing method of the first aspect of the present invention, since the adjustment pin that defines the disk support protrusion is provided so that the position can be adjusted, injection molding is performed by adjusting the position of the adjustment pin. The height of the disk support portion of the turntable can be set, and a turntable with little surface runout can be manufactured relatively easily and inexpensively.
[0041]
According to the turntable manufacturing method of the second 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 do.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a main part of an embodiment of a recording disk drive device according to the present invention.
2 is a perspective view showing a turntable of the recording disk drive device of FIG. 1. FIG.
FIG. 3 is a cross-sectional view showing a mold body used when injection molding a turntable.
4 is a cross-sectional view for explaining one adjustment of an adjustment pin in the mold body of FIG. 3. FIG.
FIGS. 5A to 5C are cross-sectional views for explaining a turntable injection molding process. FIG.
[Explanation of symbols]
2 Spindle motor 6 Rotor 20 Rotating shaft 40 Recording disk 42 Turntable 44 Suction means 46 Table body 48 Disk support projection 50 High friction member 60 Clamp member 74 First mold 76 Second mold 84 First member 87 Projecting pin 88 Injection molding space 90 Molten resin flow path 92 Adjustment pin

Claims (2)

Manufactures a turntable having a table body rotated in a predetermined direction by a rotation drive mechanism, and a plurality of disk support protrusions for supporting a recording disk provided in the table body at intervals in the circumferential direction. In the manufacturing method to
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 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 protrusion. A method of manufacturing a turntable, characterized in that the height of a corresponding disk support protrusion is set by defining a surface and adjusting the position of each adjustment pin. The first mold is attached to the first member, the second mold is attached to the second member, and the position of each of the plurality of adjustment pins is adjustable with respect to the first mold. attached by interposing an adjusting spacer between the first member and each of the plurality of adjustment pin, turn claim 2 Symbol mounting positions of the adjustment pin relative to the first mold is adjusted Table manufacturing method .

Images