Abstract:
A turn table of a spindle motor in which a small-diameter disk can be freely attached and detached is disclosed, wherein the disk insertion unit includes 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, and wherein the claw includes 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 is 14.94˜l4.96 mm and an outer diameter of the vertical claw portion at the claw is 15.17˜15.23 mm.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit under 35 U.S.C. § 119 of Korean Application Number 10-2008-0095422, filed Sep. 29, 2008, which is hereby incorporated by reference in its entirety. 
       BACKGROUND 
       [0002]    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 
       [0003]    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. 
         [0004]    A turn table for spindle motor according to one aspect of the present disclosure comprises: a disk insertion unit into which an inner periphery of a disk is inserted; and a claw resiliently pressing 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 is smaller by 0.01%˜0.15% than the inner periphery of the small-diameter disk to enable a chucking of a small-diameter disk having an inner diameter of an inner periphery smaller than 15 mm out of disks. 
         [0005]    A turn table for spindle motor according to another aspect of the present disclosure comprises: 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 includes 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, and wherein the claw includes 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 is 14.94˜14.96 mm and an outer diameter of the vertical claw portion at the claw is 15.17˜15.23 mm. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0006]      FIG. 1  is a cross-sectional view illustrating a spindle motor according to an imaginary exemplary embodiment for comparison with the present invention. 
           [0007]      FIG. 1   a  is a perspective view illustrating a turn table of  FIG. 1 . 
           [0008]      FIG. 2  is a schematic view defining dimensions of a turn table according to the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0009]      FIG. 1  is a cross-sectional view illustrating a spindle motor according to an imaginary exemplary embodiment for comparison with the present invention, and  FIG. 1   a  is a perspective view illustrating a turn table of  FIG. 1 . 
         [0010]    As illustrated in  FIGS. 1 and 1   a , a turn table  10  supportively mounted by a disk  50  is formed of a single body, and includes an axial coupling unit  11 , a disk insertion unit  13 , a disk accommodation unit  15 , and a claw. 
         [0011]    The axial coupling unit  11  having a substantially pipe-shaped body is coupled at an inner periphery by a rotation shaft  21  press-fitted thereinto. The disk insertion unit  13  having a substantially ring-shaped body is separated from an outer periphery of the axial coupling unit  11  at a predetermined distance, and is inclined at an outer lateral unit into which a disk  50  is inserted. The disk accommodation unit  15  is extensively formed from the outer periphery of the disk insertion unit  13  and is mounted with the disk  50 . 
         [0012]    A plurality of opening units is formed along the disk insertion unit  13  and is formed with a claw  17 . The claw  17  is independently operated from the disk insertion unit  13  and resiliently supports the disk  50  so that a center of the disk  50  inserted into the disk insertion unit  13  can correspond with that of the rotation shaft  21 . 
         [0013]    An inner diameter of a disk is conventionally 15.00 mm˜5.15 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 invention will now be described for solving the aforementioned drawbacks. 
         [0014]      FIG. 2  is a schematic view defining dimensions of a turn table according to the present invention. 
         [0015]    Referring to  FIG. 2 , the present invention serves to limit an outer diameter of a vertical portion  124  at a disk insertion unit  120  and that of a vertical claw portion  114  of a claw  110  to allow free attachment and detachment of a disk, and preferably, heights of the disk insertion unit  120  and claw  110  are restrained to enable a stable obtainment of recording and reading. 
         [0016]    More preferably, deterioration of centering performance caused by narrowing an outer diameter of the vertical portion  124  at the disk insertion unit  120  and that of the vertical claw portion  114  at the claw  110  may be improved by restraining the insertion of the claw  110 . 
         [0017]    Referring again to  FIG. 2 , the disk insertion unit  120  includes an inclination portion  122  and a vertical portion  124  vertically and extensively formed from the inclination portion  122  to a disk insertion unit  130  and contacted by inner periphery of the disk, where the inclination portion  122  functions to guide the disk to be inserted, and the vertical portion  124  functions to chuck the disk along with the claw  110 . 
         [0018]    An outer diameter of the vertical portion  124  at 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%˜0.15%. 
         [0019]    If the outer diameter of the vertical portion  124  is greater than 14.96 mm, the chucking of the small-diameter disk is not smoothened, and if the outer diameter of the vertical portion  124  is 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. 
         [0020]    A height of the vertical portion  124  is a height from a disk accommodation unit  130  to a boundary between the inclination portion  122  and the vertical portion  124  of the disk insertion unit  120 . However, the height of the vertical portion  124  is actually a height up to the boundary from a pad  132  because the disk accommodation unit  130  is installed with the pad  132  on which the disk is accommodated. 
         [0021]    According to the present invention, the height of the vertical portion  124  is 0.1 mm˜0.6 mm, which is approximately 8%˜50% of a 1.2 μm thickness disk. 
         [0022]    If the height of the vertical portion  124  is 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. 
         [0023]    Referring to  FIG. 2 , the claw  110  includes an inclination claw portion  112  and a vertical claw portion  114 , where the inclination claw portion  112  serves to guide the disk that is inserted and the vertical claw portion  114  serves to chuck the disk. 
         [0024]    Now, an exemplary embodiment of an outer diameter of the vertical claw portion  114  at the claw  110  will be explained. 
         [0025]    The outer diameter of the vertical claw portion  114  at the claw  110  is limited to 15.17 mm to 15.23 mm. 
         [0026]    If the outer diameter of the vertical claw portion  114  at the claw  110  is 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 claw  110  due 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. 
         [0027]    The height of the vertical claw portion  114  at the claw  110  is a height from the pad  132  of the disk accommodation unit  130  to a boundary between the inclination portion  122  and the vertical claw portion  114  of the claw  110 , as in the case of the disk insertion unit  120 . 
         [0028]    According to the present invention, the height of the vertical claw portion  114  at the claw  110  is 0.2 μm˜0.5 mm, which is approximately 15%˜42% of a 1.2 mm thickness disk. 
         [0029]    If the height of the vertical claw portion  114  is 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 claw  110 , 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. 
         [0030]    As noted above, there is a high likelihood of deteriorating the centering performance as the outer diameter of the disk insertion unit  120  is getting smaller, such that the deteriorated centering performance can be offset by limitation of claw insertion force. 
         [0031]    The claw insertion force defines a force of a claw  110  to 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. 
         [0032]    As noted above, the outer diameter and height of vertical portion  124  at the disk insertion unit  120 , the outer diameter and height of vertical claw portion  114  at the claw  110  and 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. 
         [0033]    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. 
         [0034]    Any reference in this specification to “one embodiment,” “an embodiment,” “exemplary embodiment,” etc., means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the disclosure. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with any embodiment, it is submitted that it is within the purview of one skilled in the art to affect such feature, structure, or characteristic in connection with others of the embodiments. 
         [0035]    Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this invention. More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the disclosure, the drawing and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art.