JP2000339921A - Turntable and its manufacture and disk-driving apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent disks from slipping by enhancing a frictional force to disks in a turntable used in a disk-driving apparatus, and to reduce face oscillations of disks by constituting the turntable so that a disk posture can be highly accurately supported. SOLUTION: A contact layer 25 provided with an elasticity and formed of a synthetic rubber or the like is coated on a load face 24 of a molded base. The contact layer 25 is formed totally to the annular load face 24, so that a plane pattern is made a ring. The contact layer 25 is partly circular in section having a convex surface (arc-shaped face or cylindrical face). The contact layer 25 is formed by applying a resin not set by a dispenser into the ring shape and setting the resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a turntable, a method of manufacturing the same, and a disk drive, and more particularly to a turntable suitable for use in a disk drive for rotating a disk as an information recording medium such as an optical recording disk. Regarding the structure of the table.

[0002]

2. Description of the Related Art In general, as shown in FIG. 5, a disk drive 10 for rotating an optical recording disk such as a CD or a DVD has a disk-shaped turntable 11 made of a synthetic resin or the like, and a turntable 11 made of the same. And a clamp disk 12 made of a magnetic material and disposed so as to oppose the magnetic disk 11. The inner periphery 100a of the disk 100 is sandwiched and held by the turntable 11 and the clamp disk 12 from both sides, and the disk 100 is rotated by rotating the turntable 11. The turntable 11 has a disc 100
A mounting surface 11a for mounting the inner peripheral portion 100a of the disk 100 is formed, and a ring-shaped material made of a material having a high coefficient of friction for preventing the disk 100 from slipping, such as synthetic rubber, is formed on the mounting surface 11a. Are fixed by adhesive.

The disk drive device 10 rotatably supports a rotary shaft 14 inserted and fixed in a center hole 11b of a turntable 11 in an axial direction and a thrust direction in a rotatable manner. The turntable 11 engaged with the rotor 16 is driven to rotate. Also, a center ring 17 is provided on the center shaft portion 11c of the turntable 11.
The center ring 17 is slidably inserted in the axial direction.
Biased away from Center ring 17
A tapered surface 17a facing obliquely upward is formed on the outer peripheral portion of the disk 100, and the inner edge portion 100b of the disk 100 is engaged with the tapered surface 17a. Further, a center cap 19 is attached to the upper end of the center shaft portion 11c of the turntable 11, and a ring-shaped magnet 19a is fixed to the center cap 19.

[0004] When the disk 100 is supplied onto the turntable 11 of the disk drive 10, the clamp disk 12 descends and is attracted by the magnet 19 a in the center cap 19. Disc 100 is a clamp disc 1
The inner edge 100b of the disk 100 contacts the tapered surface 17a of the center ring 17 while the center ring 17 is moved downward against the elastic force of the coil spring 18 while being pressed downward by the second pressing portion 12a. The center position of 100 is corrected. Finally, as shown in FIG. 5, the inner peripheral portion 100a of the disc 100 includes the friction sheet 13 on the turntable 11 and the clamp disc 1
2 is sandwiched.

In the conventional turntable, a ring-shaped friction sheet 13 is attached to the mounting surface 11a as described above, or masking is applied to the mounting surface 11a to spray resin such as synthetic rubber. It is painted to form a ring-shaped friction layer. These friction sheets and friction layers are for preventing the disk 100 from slipping with respect to the turntable 11 while being pressed by the clamp disk 12.

[0006]

However, in recent years, the rotational speed and rotational acceleration of a disk drive have been increasing in order to increase the speed of reading and writing information. Extremely high frictional forces are being required for complete prevention. However, it is difficult to obtain a sufficient frictional force depending on the friction sheet or the friction layer provided on the conventional turntable, and the flatness of the surface of the friction sheet or the friction layer is reduced to prevent the disk from slipping. It is necessary to increase the contact area by forming with high precision, or to use an expensive material having an extremely high friction coefficient. Also, in order to increase the frictional force of the friction sheet or the friction layer, the pressing force of the clamp disk may be increased by using a magnet having a high magnetic attraction force, which causes a problem that the manufacturing cost increases. Was.

In the conventional turntable, since a friction sheet is stuck on a mounting surface or a friction layer is coated by masking, the operation is complicated and labor is required. However, there is a problem that it is difficult to increase the accuracy of the properties or thickness, and that there is a high risk of occurrence of surface run-out of the disk due to insufficient surface accuracy (insufficient flatness) of the friction sheet or the friction layer. .

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a turntable for use in a disk drive device, by increasing the frictional force on the disk to prevent the disk from slipping and to prevent the disk from slipping. It is an object of the present invention to provide a novel structure capable of reducing the disk runout by configuring the attitude to be able to be supported with high precision.

[0009]

According to the present invention, there is provided a turntable having a mounting surface facing a disk to be mounted, and supporting the surface of the disk on the mounting surface. A contact body having elasticity for the contact, and a surface shape of the contact body is formed in a convex curved shape.

According to the present invention, the top of the contact body is pressed against the disk by attaching the elastic contact body having the convex surface to the mounting surface facing the disk. Since the support is performed in the state, the pressing force can be locally concentrated, so that the slip of the disk can be reduced without requiring the flatness of the contact surface with the disk.

In the present invention, it is preferable that a plurality of portions of the disk are configured to be supported by a top portion of a surface of the contact body. According to this means, since the plurality of portions of the disk are supported by the tops of the surface of the contact body, the accuracy of the support posture of the disk is determined by the height accuracy between the tops of the contact bodies. The flatness of the contact surface is not required, so simply securing the height accuracy between the tops of multiple parts of the contact body or the height of the continuous tops makes it easier to achieve a higher disk posture than before and reduces disk runout. can do. Here, as a case where a plurality of portions of the disc are supported at the top of the contact body, for example, when a plurality of independent contact bodies are formed at different positions on the mounting surface of the turntable, an integral continuous There is a case where the contact body provided has a continuous top, a case where an integrated continuous contact body has a plurality of tops arranged discretely from each other, or the like.

In the present invention, it is preferable that the contact body extends in an arc shape in the rotation direction of the disk. According to this means, the contact body can be easily applied and formed by a dispenser or the like, and the disk can be supported at a large number of positions in the circumferential direction.
Since the runout of the disk can be reduced and the contact area with the disk can be increased,
It is possible to increase the frictional force against the slip of the disk.

[0013] In the present invention, it is preferable that the plurality of contact bodies are scattered in the rotation direction of the disk. According to this means, the contact body can be easily applied and formed by a dispenser or the like, and the disk can be supported at a large number of positions in the circumferential direction.
The disk runout can be reduced, and the frictional force against the disk slip can be increased.

In the present invention, it is preferable that the contact body is formed and adhered by selectively applying an uncured resin on the mounting surface and curing the resin. According to this means, the production cost can be reduced by using a contact body which has been applied with an uncured resin and cured.

Next, a disk drive device of the present invention includes the turntable, a clamp member for holding the disk between the turntable, and a rotary drive mechanism for rotating the turntable. When the disc is sandwiched between the turntable and the clamp member, the contact body is pressed and deformed so that a contact area between the disc and the contact body is increased. And According to the present invention, the contact body is elastically deformed by pressing the disc against the contact body having the convex curved surface by the clamp member, so that the contact area is increased. The disc can be attached to the turntable because the contact area between the disc and the contact body decreases due to the elasticity of the contact body by loosening the pressing force of the disc against the contact body while securing the disc. It is possible to reduce the occurrence of a situation.

Next, in the method of manufacturing a turntable according to the present invention, a dispenser capable of controlling an application amount to at least a predetermined amount is applied to a substrate having a mounting surface facing a disk to be mounted. An uncured resin is selectively applied on the surface, and the uncured resin is cured to form an elastic contact body for supporting the surface of the disk. According to the present invention, the non-effective resin is applied onto the mounting surface by the dispenser, so that the sticking operation and the masking operation are not required, and the processing can be performed quickly, and the automation is easy. Therefore, the manufacturing cost can be significantly reduced. Here, it is particularly desirable to form the contact body so that the surface shape is a convex curved surface.

In the present invention, it is preferable that the base is supported in substantially the same state as when used, and the uncured resin is applied while rotating the base. According to this means, the base is substantially in the same state as the used state (for example, when used in a disk drive, these bases are substantially similar to the state in which the base is supported by a spindle or a bearing of the disk drive). By using a shaft and bearing having a shaft support portion of the same dimensions as above, and supporting the shaft in the same manner, that is, in a horizontal state), by applying the uncured resin while rotating, The uniformity of the shape of the contact body in the circumferential direction of the turntable and the uniformity of the height of the top of the contact body can be improved. Also, in particular, a contact body having a shape extending in the circumferential direction of the turntable or a plurality of contact bodies arranged in the circumferential direction,
It can be formed easily and with high precision. in this case,
After the dispenser starts dispensing, the turntable is rotated about one turn, but only about 5 to 30 degrees,
By stopping the supply of the resin in the foreground and spinning the turntable, the application start point and the end point can be continuously connected. The optimum value of the angle varies depending on the supply amount and the rotation speed of the resin, the distance between the dispenser and the turntable, and the like.

Here, it is particularly desirable to use, as the uncured resin, a resin that exhibits an adhesive force to a member that is in contact during curing and has a lower adhesive force to a member that is in contact after curing than the adhesive force. .

In the present invention, the uncured resin is preferably a silicone rubber.

Further, in each of the above inventions, the entire mounting surface or a part of the area within the mounting surface is projected from the periphery,
It is preferable that the uncured resin is applied to this area, and the spread of the uncured resin is restricted to the area by one or both of the wettability of the uncured resin on the mounting surface and the viscosity of the uncured resin. According to this method, the amount of the uncured resin,
The surface shape of the contact body can be formed with high accuracy and high reproducibility by the wettability or viscosity of the uncured resin and the spread region of the uncured resin.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of a turntable according to the present invention and a disk drive provided with the same will be described in detail. FIG. 1 is a longitudinal sectional view showing the structure of the turntable 20 of the present embodiment. The turntable 20 comprises a disc-shaped molded base formed of a synthetic resin such as a polycarbonate resin or other material, a center shaft portion 21 having a stepped shaft hole 21a at the center, and an axial direction of the center shaft portion 21. A concave portion 22 integrally formed around the lower portion, and an opposing portion 23 formed so as to protrude slightly upward in the axial direction further around the concave portion 22 and face the lower surface of a disc (not shown) to be mounted. And a ring-shaped mounting surface 24 formed on the outer periphery of the upper surface of the opposing portion 23 so as to be slightly higher than the inner portion.

An elastic contact layer 25 made of synthetic rubber or the like is adhered on the mounting surface 24 of the molded base. The contact layer 25 is entirely formed on the mounting surface 24 formed in a ring shape in the illustrated example, and is configured so that the planar pattern becomes a ring shape. Contact layer 2
5 has a partially circular cross section as shown in the figure, and the surface of the contact layer 25 has a convex curved surface (an arc-shaped surface or a cylindrical surface).

FIG. 2 shows an example of a method of manufacturing the turntable 20. After the base of the turntable 20 is formed, the shaft 31 having the same diameter as the rotating shaft 14 shown in FIG. 5 is arranged in the same posture (that is, vertical posture), and the shaft 31 is inserted into the shaft hole 21a to temporarily attach the formed base. The molded base is rotatably supported by a rotary drive source 32 such as an electric motor having the shaft 31 as an output shaft. Then, the precision dispenser 33 is arranged at a predetermined position on the mounting surface 24 of the molded base, and the uncured resin 34 made of uncured synthetic rubber or the like is placed from the nozzle 33a of the precision dispenser 33 while rotating the base. It is applied on the surface 24 in a ring shape. Then, the discharge of the uncured resin 34 from the nozzle 33a of the precision dispenser 33 is stopped slightly before (e.g., about 5 to 30 degrees) just before the turntable 20 makes one rotation from the start of the application, and the nozzle is allowed to run idle. Although it depends on the viscosity of the uncured resin 34, the resin existing between the nozzle 33a and the mounting surface 24 fills the space between the application start point and the resin supply stop position. Can be. After the application is completed, the uncured resin 34 is cured to form the contact layer 25 described above. In the curing step of the uncured resin, if the uncured resin 34 is a natural curing type resin (for example, curing by oxidation, curing by volatilization of a solvent, or the like), the resin is allowed to stand (leave). In the case of a photocurable resin such as ultraviolet curing, light irradiation is performed.

As the precision dispenser 33, various types can be used. For example, a resin accommodating chamber for accommodating an uncured resin 34 supplied at a predetermined pressure from a resin tank (not shown) and a tip of the resin accommodating chamber are provided. And a needle valve having a needle configured to be able to advance and retreat inside the nozzle 33a. The needle is configured to periodically advance and retreat with respect to a valve seat inside the nozzle 33a. When the needle retracts from the valve seat and opens the nozzle 33a, the uncured resin is discharged from the resin storage chamber via the nozzle 33a. You. The ratio of the opening time of the nozzle 33a due to the retreat of the needle, the operation cycle of the needle (opening / closing cycle of the nozzle), the uncured resin 3
4, the amount of the uncured resin 34 discharged from the nozzle 33a is precisely adjusted by the pressure in the resin storage chamber. In the present embodiment, by precisely controlling the amount of the uncured resin 34 applied by the precision dispenser 33, the shape of the contact layer can be formed with extremely high precision.

As the uncured resin 34, it is preferable to use a material which has elasticity after curing and has a high coefficient of friction on the surface after curing. For example, silicone rubber can be used. Examples of the silicone rubber include “TSE3995” manufactured by Toshiba Silicone Co., Ltd. This silicone rubber has an adhesive function that can be used as an adhesive in an uncured state, but after curing, although the surface has a high coefficient of friction, the adhesive force is completely lost, and the adhesive force (sticking force) ) Is also significantly reduced. As described above, as the elastic contact layer 25 used in the present embodiment, a resin material that exhibits an adhesive force by being cured from an uncured state and loses an adhesive force to a new contact target after curing is used. Preferably, it is used. Thereby, the contact force of the contact layer 25 to the mounting surface of the turntable 20 (adhesive force) can be increased to prevent the contact layer 25 from peeling off, and the disk is less likely to stick to the contact layer 25. Therefore, it is easy to remove the disk.

When the mounting surface 24 slightly protrudes from the surface of the facing portion 23 as in the present embodiment, the wettability and viscosity of the resin 34 with respect to the mounting surface 24 cause The contact area of the uncured resin 34 on the surface can be limited. In this case, the viscosity of the resin 34 is as follows.
1.0 to 3.0 [Pa · s] so that the fluidity after application can be suppressed to secure shape retention characteristics and smoothness of the shape due to gravity (own weight) can be expected. Is preferable, and particularly preferably 1.5 to 2.5 [Pa · s]. If the viscosity is in this range, good reproducibility of the shape can be obtained as the cured contact layer 25.

In this embodiment, since the surface of the contact layer 25 is formed in a convex curved surface, unlike the conventional case where the disk is pressed against a flat friction surface, the posture of the disk is changed to the flat friction surface. Rather than being determined by the height distribution of the contact layer 25 formed in a ring shape. Therefore, the height distribution around the axis of the ring-shaped contact layer 25 is important for accurately positioning the disk by pressing the turntable 20 and reducing the surface runout. Precision dispenser 33 is nozzle 3
Since the amount of the resin 34 discharged from the nozzle 3a can be controlled with extremely high precision, as shown in FIG.
4 is applied and cured, whereby the posture of the loaded disk can be set with high accuracy.

The nozzle 33 of the precision dispenser 33
a has a substantially circular opening, so that the resin 34 is placed on the mounting surface 24 so that the center of the contact layer 25 rises.
It can be applied on top. Especially when the viscosity of the resin 34 is large, the nozzle 3 of the precision dispenser 33
Since the cross-sectional shape of the contact layer 25 is also affected by the opening shape of the contact layer 3a, it is necessary to form the opening shape of the nozzle 33a in accordance with the desired cross-sectional shape of the contact layer 25. Generally, when applying the contact layer 25 having a planar shape extended as described above, the turntable 20 and the precision dispenser 3 are applied.
Nozzle 33a seen in the direction of relative movement (circular direction) with No. 3
The thickness of the contact layer 25 is determined according to the opening width of the contact layer. Therefore, when the nozzle 33a having the substantially circular opening shape is used as described above, the contact layer 25 has the thickest shape at the radial center (central portion in the width direction).

In the above embodiment, the contact layer 25 is formed in a ring shape. However, as shown in FIGS. 3A to 3D, a contact layer having a different planar shape may be formed. FIG. 3A shows a case where a large number of contact layers 35 each having a substantially circular shape in a plane are scattered on the mounting surface 24 in the circumferential direction of the turntable 20.
In this case, the disk is supported by a large number of contact layers 35 arranged in the circumferential direction of the turntable 20, that is, at multiple points. FIG. 3B shows a case where the plurality of contact layers 36 are formed in an arc shape extending to a certain extent in the circumferential direction of the turntable 20.

FIG. 3C shows a case where a plurality of (two in the illustrated example) ring-shaped or arc-shaped contact layers 37 and 38 having different diameters are formed concentrically in a state of being separated from each other. Is shown. In this case, the disc is supported at a plurality of locations in the radial direction of the turntable 20 as well as in the circumferential direction of the turntable 20. Further, in FIG. 3D, resin is applied concentrically in a ring shape or an arc shape at a plurality of positions (two in the illustrated example) having different diameters on the mounting surface 24, and overlapped with each other. The case where the integrated contact layer 39 is formed is shown.

In each of the cases shown in FIG. 3, as in the above embodiment, the contact layer extends or is arranged in the circumferential direction of the turntable 20, so that the disk is supported over a plurality of portions in the circumferential direction. Therefore, the runout of the disk can be reduced.

In the above-described embodiment and each of the modifications, the formation region of the contact layer 25 is extremely limited.
Moreover, since the surface of the contact layer is formed in a convex curved shape,
The contact area between the disk and the disk is smaller than that in the related art, so that the clamping force on the disk in the disk drive device 10 shown in FIG. 5 is applied intensively to the contact layer. Therefore, the contact layer is elastically deformed to increase the contact area as described later, and a high frictional resistance against the disk can be obtained by a large pressure generated by the concentration of the pressing force.

In each of the embodiments and the modifications described above, since the contact layer has a convex cross-sectional shape, the surface of the disk may not be applied with only a very small pressing force. In the case of contact with the surface, the contact area between them is small, and is close to a point contact or a line contact. However, by increasing the pressing force, the elastic contact layer is deformed, and the contact area between them is increased. Therefore, even if the heights (thicknesses) of the surfaces of the contact layers are different from each other, they are canceled out by the elastic deformation of the respective portions, and the disk can be supported substantially horizontally.

FIG. 4 shows the above state and situation. As shown in FIG. 4A, a contact layer 25 is formed on a mounting surface 24 formed on the surface of the facing portion 23, and the disk 100 is placed on the contact layer 25. Then, the disc 100 is pressed from above by the clamp disc 12 shown in FIG.
0 is clamped between the clamping disk 12 and the contact layer 25.
In this state, the contact layer 25 is elastically deformed because it is pressed from above by the disc 100, and as shown in FIG.
0 and the contact area between the contact layer 25 and the disk 100
A sufficient frictional force can be generated between the motor and the turntable 20.

On the other hand, the clamp disk 12 is
When the pressing force is released by separating the contact layer 25 from the disk 100, the contact layer 25 restores its shape to a state almost not in contact with the disk 100 due to its own elasticity.
As shown in (c), the contact area between the disc 100 and the contact layer 25 is greatly reduced. As a result, the adhesive force between the disk 100 and the contact layer 25 is sharply reduced.
It is possible to avoid occurrence of a situation in which 00 does not come off while being adhered to the contact layer 25.

In the turntable 20 provided with the above-mentioned contact layer 25, by using the disk drive device 10 shown in FIG. 5, a sufficient frictional force with respect to the disk 100 can be obtained, and the disk can be supported with high precision. Therefore, surface runout can be reduced, and sticking is prevented even when the disk is removed.
Further, since the above-mentioned contact layer can be formed very easily by coating with a dispenser, it is possible to significantly reduce the production cost as compared with the conventional techniques such as sticking of a friction sheet and masking coating of a friction layer. Become.
In addition, since the contact layer is formed by application using a dispenser as described above, it is possible to easily cope with a change in the shape and size of the turntable on the base side, and to easily change the shape and size of the contact layer.

It should be noted that the turntable and the disk drive of the present invention are not limited to the above-described examples, and various changes can be made without departing from the scope of the present invention.

[0038]

As described above, according to the present invention,
Since the elastic contact body having a convex curved surface is attached to the mounting surface facing the disk, the top of the contact body is supported while being pressed against the disk. So you can concentrate locally
It is possible to reduce the slip of the disk without requiring the flatness of the contact surface with the disk.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a structure of an embodiment of a turntable according to the present invention.

FIG. 2 is an explanatory view showing a step of manufacturing the turntable of the embodiment (a resin applying step for forming a contact layer).

FIG. 3 is a partial plan view of a turntable showing a modification of the embodiment.

FIG. 4 is enlarged cross-sectional views (a) to (c) showing functions of a contact layer of the embodiment.

FIG. 5 is a schematic longitudinal sectional view showing a schematic configuration of a conventional disk drive device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Disk drive device 12 ... Clamp disk 13 ... Friction sheet 17 ... Center ring 18 ... Coil spring 19 ... Center cap 19a ... Magnet 20 ... Turntable 23 ... Opposing part 24 ... Mounting surface 25 ... Contact layer 33 ... Precision dispenser 33a ... Nozzle 100 ... Disk 100a ... Inner circumference 100b ... Inner edge

Claims (9)

[Claims] A contact surface having an elastic surface for supporting a surface of the disk is attached to the mounting surface, and the surface shape of the contact member is adjusted. A turntable characterized by being formed in a convex curved shape. 2. The turntable according to claim 1, wherein a plurality of portions of the disk are supported by a top portion of a surface of the contact body. 3. The turntable according to claim 2, wherein the contact body extends in an arc shape in a rotation direction of the disk. 4. The turntable according to claim 2, wherein a plurality of the contact bodies are scattered in a rotation direction of the disk. 5. The method according to claim 1, wherein:
In the paragraph, the contact body is formed and adhered by selectively applying an uncured resin on the mounting surface and curing the contact body. 6. One of claims 1 to 4
The turntable according to the paragraph, and a clamp member that clamps the disk between the turntable, and a rotation drive mechanism that rotationally drives the turntable,
When the disc is sandwiched between the turntable and the clamp member, the contact body is pressed and deformed so that a contact area between the disc and the contact body is increased. Disk drive. 7. An uncured resin is selectively applied to a substrate having a mounting surface facing a disk to be mounted by a dispenser capable of controlling an application amount to at least a predetermined amount. A method of manufacturing a turntable, wherein an uncured resin is cured to form an elastic contact body for supporting the surface of the disk. 8. The method for manufacturing a turntable according to claim 7, wherein the uncured resin is applied while rotating the substrate while supporting the substrate substantially in the same state as when the substrate is used. 9. The method according to claim 7, wherein the uncured resin is a silicone rubber.