Turn table for spindle motor

A turn table of a spindle motor is provided, wherein an outer diameter of a vertical portion at the disk insertion unit facing an inner periphery of a small-diameter disk is smaller by 0.01% to 0.15% than the inner periphery of the small-diameter disk to enable a chucking of the small-diameter disk having an inner diameter of an inner periphery smaller than 15 mm.

BACKGROUND

The present disclosure relates to a turn table of a spindle motor. A DVD (digital video disk) is widely used due to advantage of information recording capacity 6˜8 times larger than that of a CD (compact disk). The DVD has a very narrow gap between tracks in which information is recorded as DVD has a large capacity. Due to the fact that the gap is narrow between the tracks, a resiliently supporting claw is applied to accord a center of the DVD on which a turn table is mounted with that of a rotation shaft.

BRIEF SUMMARY

Exemplary aspects of the present disclosure are to substantially solve at least the above problems and/or disadvantages and to provide at least the advantages as mentioned below. Thus, the present disclosure intends to provide a turn table of a spindle motor having an advantageous capacity of free attachment and detachment of a small-diameter disk.

In one general aspect of the present disclosure, there may be provided a turn table of spindle motor, the turn table may comprises a disk insertion unit into which an inner periphery of a disk is inserted; and a claw resiliently configured to press the inserted disk by being protruded at the disk insertion unit, wherein an outer diameter of a vertical portion at the disk insertion unit facing an inner periphery of a small-diameter disk may be smaller by 0.01% to 0.15% than the inner periphery of the small-diameter disk to enable a chucking of the small-diameter disk having an inner diameter of an inner periphery smaller than 15 mm.

In some exemplary of the present invention, an outer diameter of the vertical portion at the disk insertion unit may range from 14.94 mm to 14.96 mm.

In some exemplary of the present invention, a height of the vertical portion at a disk insertion unit may range from 8% to 50% of thickness of a disk.

In some exemplary of the present invention, the height of the vertical portion may range from 0.1 mm to 0.6 mm.

In some exemplary of the present invention, an outer diameter of the claw may range from 15.17 mm to 15.23 mm.

In some exemplary of the present invention, a claw insertion force may be less than 80% of a clamping force.

In some exemplary of the present invention, the height of the vertical claw portion at the claw may range from 15% to 42% of a thickness of a disk.

In some exemplary of the present invention, the height of the vertical claw portion at the claw may range from 0.2 mm to 0.5 mm.

In another general aspect of the present disclosure, there may be provided a turn table for spindle motor, the turn table may comprise an axial coupling unit to which a rotation shaft is coupled; a disk insertion unit into which a disk is inserted; an accommodation unit in which the inserted disk is accommodated; and a claw formed at the disk insertion unit for resiliently supporting the inserted disk apart from the disk insertion unit, wherein the disk insertion unit may comprises an inclination portion guiding the inserted disk, and a vertical portion extensively formed from the inclination portion to the disk accommodation unit to allow an inner periphery of the disk to be brought into contact, wherein the claw may comprise an inclination claw portion guiding the inserted disk, and a vertical claw portion bent from the inclination claw portion to chuck the disk, and wherein an outer diameter of the vertical portion at the disk insertion unit may range from 14.94 mm to 14.96 mm and an outer diameter of the vertical claw portion at the claw may range from 15.17 mm to 15.23 mm.

In some exemplary of the present invention, a height from the disk accommodation unit to a boundary between the inclination portion and the vertical portion of the disk insertion unit may range from 0.1 mm to 0.6 mm, and a height from the disk accommodation unit to a boundary between the inclination claw portion and the vertical claw portion of the claw may range from 0.2 mm to 0.5 mm.

In some exemplary of the present invention, a claw insertion force may be less than 80% of a clamping force.

DETAILED DESCRIPTION

Advantages and features of the present disclosure may be understood more readily by reference to the following detailed description of exemplary embodiments and the accompanying drawings. Thus, the present disclosure is not limited to the exemplary embodiments which will be described below, but may be implemented in other forms. Accordingly, the described aspect is intended to embrace all such alterations, modifications, and variations that fall within the scope and novel idea of the present disclosure.

FIG. 1is a cross-sectional view illustrating a spindle motor according to an imaginary exemplary embodiment for comparison with the present disclosure, andFIG. 1ais a perspective view illustrating a turn table ofFIG. 1.

As illustrated inFIGS. 1 and 1a, a turn table10supportively mounted by a disk50is formed of a single body, and includes an axial coupling unit11, a disk insertion unit13, a disk accommodation unit15, and a claw17.

The axial coupling unit11having a substantially pipe-shaped body is coupled at an inner periphery by a rotation shaft21press-fitted thereinto. The disk insertion unit13having a substantially ring-shaped body is separated from an outer periphery of the axial coupling unit11at a predetermined distance, and is inclined at an outer lateral unit into which a disk50is inserted. The disk accommodation unit15is extensively formed from the outer periphery of the disk insertion unit13and is mounted with the disk50.

A plurality of opening units14is formed along the disk insertion unit13and is formed with a claw17. The claw17is independently operated from the disk insertion unit13and resiliently supports the disk50so that a center of the disk50inserted into the disk insertion unit13can corresponds with that of the rotation shaft21.

An inner diameter of a disk is conventionally 15.00 mm˜15.15 mm, and in case of a DVD having two disks vertically stacked, a so called small-diameter disk may be manufactured having an actual inner diameter of 14.96 mm due to disaccord of the centers of two disks during stacking. If the center-disaccorded disks are mounted on the conventional turn table, there is a high likelihood of causing a defect known as a disk chucking. Exemplary embodiments of the present disclosure will now be described for solving the aforementioned drawbacks.

FIG. 2is a schematic view defining dimensions of a turn table according to the present disclosure.

Referring toFIG. 2, the present disclosure serves to limit an outer diameter of a vertical portion124at a disk insertion unit120and that of a vertical claw portion114of a claw110to allow free attachment and detachment of a disk, and preferably, heights of the disk insertion unit120and claw110are restrained to enable a stable obtainment of recording and reading.

More preferably, deterioration of centering performance caused by narrowing an outer diameter of the vertical portion124at the disk insertion unit120and that of the vertical claw portion114at the claw110may be improved by restraining the insertion of the claw110.

Referring again toFIG. 2, the disk insertion unit120includes an inclination portion122and a vertical portion124vertically and extensively formed from the inclination portion122to a disk accommodation unit130and contacted by inner periphery of the disk, where the inclination portion122functions to guide the disk to be inserted, and the vertical portion124functions to chuck the disk along with the claw110.

An outer diameter of the vertical portion124at the disk insertion is limited to 14.94 mm to 14.96 mm, which is a limited dimension to allow being smaller than an inner diameter of a small-diameter disk by approximately 0.01%˜15%.

If the outer diameter of the vertical portion124is greater than 14.96 mm, the chucking of the small-diameter disk is not smoothened, and if the outer diameter of the vertical portion124is smaller than 14.96 mm, the disk cannot be stably supported during chucking of the disk, such that recording and reading errors of disk may occur due to trembling of disk caused by centrifugal force when the disk is rotated at a high speed.

A height of the vertical portion124is a height from a disk accommodation unit130to a boundary between the inclination portion122and the vertical portion124of the disk insertion unit120. However, the height of the vertical portion124is actually a height up to the boundary from a pad132because the disk accommodation unit130is installed with the pad132on which the disk is accommodated.

According to the present disclosure, the height of the vertical portion124is 0.1 mm˜0.6 mm, which is approximately 8%˜50% of a 1.2 mm thickness disk.

If the height of the vertical portion124is greater than 0.6 mm, the chucking of small-diameter disk cannot be smoothened, and if smaller than 0.1 mm, the disk cannot be stably supported during chucking of the disk, such that recording and reading errors of disk may occur due to trembling of disk caused by centrifugal force when the disk is rotated at a high speed.

Referring toFIG. 2, the claw110includes an inclination claw portion112and a vertical claw portion114, where the inclination claw portion112serves to guide the disk that is inserted and the vertical claw portion114serves to chuck the disk.

Now, an exemplary embodiment of an outer diameter of the vertical claw portion114at the claw110will be explained.

The outer diameter of the vertical claw portion114at the claw110is limited to 15.17 mm to 15.23 mm.

If the outer diameter of the vertical claw portion114at the claw110is greater than 15.23 mm, there is a high likelihood of the chucking of a small-diameter not being smoothened to deform or break the claw110due to repeated attachment and detachment. If smaller than 15.17 mm, the disk cannot be stably supported during chucking of the disk, such that recording and reading errors of disk may occur due to trembling of disk caused by centrifugal force when the disk is rotated at a high speed.

The height of the vertical claw portion114at the claw110is a height from the pad132of the disk accommodation unit130to a boundary between the inclination claw portion112and the vertical claw portion114of the claw110, as in the case of the disk insertion unit120.

According to the present disclosure, the height of the vertical claw portion114at the claw110is 0.2 mm˜0.5 mm, which is approximately 15%˜42% of a 1.2 mm thickness disk.

If the height of the vertical claw portion114is greater than 0.5 mm, the disk chucking of small-diameter disk cannot be smoothened due to repeated attachment and detachment of disks to generate a high likelihood of deforming or breaking the claw110, and if smaller than 0.2 mm, the disk cannot be stably supported during chucking of the disk, such that recording and reading errors of disk may occur due to trembling of disk caused by centrifugal force when the disk is rotated at a high speed.

As noted above, there is a high likelihood of deteriorating the centering performance as the outer diameter of the disk insertion unit120is getting smaller, such that the deteriorated centering performance can be offset by limitation of claw insertion force.

The claw insertion force defines a force of a claw110to grasp a disk, where if the insertion force is great, the centering performance may improve but the disk chucking defects may occur if the claw insertion force becomes greater than the clamping force. Therefore, it is preferable that the claw insertion force be designed not to go over 80% of the clamping force at the maximum.

As noted above, the outer diameter and height of vertical portion124at the disk insertion unit120, the outer diameter and height of vertical claw portion114at the claw110and the insertion force of claw can be selectively and properly restrained within a limited scope to smoothly chuck the small-diameter disk, and optimization of disk trembling and run-out can be restrained in the occurrence of errors on disk recording and reading.

According to the aforementioned configuration, an outer diameter and height of vertical portion at a disk insertion unit, an outer diameter and height of vertical claw portion at a claw and an insertion force of claw can be selectively and properly restrained within a limited scope to smoothly chuck a small-diameter disk, and optimization of disk trembling and run-out can be restrained in occurrence of errors on disk recording and reading.