Patent Abstract:
A disk chucking apparatus for a disk player, having: a turntable on which a disk is seated; a clamper unit to clamp the disk to the turntable; and a holder unit, disposed on a main chassis to be approachable to and separable from the turntable, and pressing the clamper unit when the disk is clamped to the turntable, the clamper unit being rotatable.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims the benefit under 35 U.S.C.  §119(   a ) of Korean Patent Application No.  2004-62013 , filed on Aug. 6, 2004, in the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference.  
       BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to a disk player, and more particularly, to a disk chucking apparatus for a small-sized disk player.  
         [0004]     2. Description of the Related Art  
         [0005]     A disk player records data on a disk such as a compact disk (CD), a CD-ROM, a digital video disk (DVD), or a DVD-ROM and/or reproduces data from the disk. And the disk player has a disk loading apparatus to load the disk to a position for recording or reproducing the data. A disk is inserted into the disk player and conveyed to a chucking position by a disk conveyance apparatus. After arriving at the chucking position, the disk is rotatably clamped on a turntable by a disk chucking apparatus.  
         [0006]      FIGS. 1A and 1B  are side section views showing a conventional disk chucking apparatus before chucking and after chucking, respectively. Referring to  FIGS. 1A and 1B , the conventional disk chucking apparatus has a clamper  52 , a magnet  92 , a yoke  93 , a holder  10 , and a turntable  90 .  
         [0007]     The clamper  52  consists of an upper clamper  54  and a lower clamper  58 . The upper clamper  54  and the lower clamper  58  are assembled with each other such that a hook  56  formed on the lower clamper  58  is hooked into a hook recess  57  formed in the upper clamper  54 . The magnet  92  is interposed between the upper clamper  54  and the lower clamper  58 . The yoke  93  is disposed on the top of the magnet  92  to reinforce a magnetic force between the magnet  92  and the turntable  90 . The holder  10  is located between the upper clamper  54  and the lower clamper  58  to support the clamper  52 , and moves up and down in relation to the movement of a slider (not shown) disposed on a main chassis (not shown). The turntable  90  is rotated by a spindle motor  94  to rotate a disk D seated thereon. The turntable  90  has a magnetic substance  70  disposed thereon to generate an attraction with respect to the magnet  92 .  
         [0008]     Operation of the disk chucking apparatus having the above construction will now be described. The holder  10  descends in relation to the movement of the slider (not shown). The clamper  52  moves down a predetermined distance together with the holder  10 . The clamper  52  further descends due to a magnetic attraction between the magnet  92  and the magnetic substance  70 . The disk D conveyed and positioned between the clamper  52  and the turntable  90  is clamped to the turntable  90  by the clamper  52 . Then, the holder  10  further descends and is located between the upper clamper  54  and the lower clamper  58  without contacting either the upper clamper  54  or the lower clamper  58 , so that a space is formed to allow the clamper  52  to be rotated. Through the above-described process, operation of chucking the disk D is completed as shown in  FIG. 1B . After that, the clamped disk D rotates together with the turntable  90  and the clamper  52 .  
         [0009]     At this time, the disk D may be eccentrically rotated due to an eccentricity of the disk D, which causes a wobble of the disk D. To prevent the wobble, the disk D has to be clamped with a predetermined clamping force. The predetermined clamping force is maintained by the attraction between the magnet  92  and the magnetic substance  70 . The magnet  92  is required to have a magnetic force sufficient to maintain the clamping force constantly.  
         [0010]     To release the disk D from the chucking state, a driving motor (not shown) is rotated in a reverse direction to the direction of the loading process, and moves the slider (not shown) on the main chassis (not shown) in an unloading direction. Then, the holder  10  ascends in relation to the movement of the slider (not shown). The clamper  52  is distanced from the disk D as the holder  10  ascends. At this time, the holder  10  has to overcome the magnetic force to move the clamper  52  upwardly.  
         [0011]     In chucking the disk D or releasing the disk D from the chucking state, the magnet  92  is required to have a high magnetic force sufficient to prevent the wobble, which is caused by the rotation of the disk D. But the magnet  92  having the high magnetic force is expensive, and when the disk D is released from the chucking state, the high magnetic force generates a load that hinders the ascending movement of the holder  10  to distance the clamper  52  from the disk D.  
         [0012]     Also, since the magnet  92  is interposed between the upper clamper  54  and the lower clamper  58 , it increases the height of the clamper  52 , which causes an increase of a size of the disk player.  
         [0013]     But since a compact-sized or a slim-type disk player is preferred recently, there is a demand for a compact-sized disk player.  
       SUMMARY OF THE INVENTION  
       [0014]     The present invention has been developed to solve the above problems in the related art. Accordingly, an aspect of the present invention is to provide a disk chucking apparatus for a disk player having an improved construction capable of reducing a load in releasing a disk from a chucking state.  
         [0015]     Another aspect of the present invention is to provide a disk chucking apparatus of an improved construction for a compact-sized disk player and a slim-type disk player.  
         [0016]     The above and other aspects of the present invention are achieved by providing a disk chucking apparatus for a disk player, having: a turntable on which a disk is seated; a clamper unit to clamp the disk to the turntable; and a holder unit, disposed on a main chassis to be approachable to and separable from the turntable, and pressing the clamper unit when the disk is clamped to the turntable, the clamper unit being rotatable.  
         [0017]     According to one aspect, the holder unit has a holder plate disposed on the main chassis, and a press member disposed on the holder plate to press a contact part upwardly protruding from a center of the clamper unit when the disk is clamped to the turntable.  
         [0018]     According to one aspect, the press member is a plate spring. According to one aspect, the contact part is dome-shaped.  
         [0019]     The above and other aspects are also achieved by providing a disk chucking apparatus for a disk player, having: a turntable on which a disk seated, the turntable having a magnet disposed thereon; a holder unit disposed on a main chassis to be approachable to and separable from the turntable; a clamper disposed at the holder unit, to clamp the disk seated on the turntable; and a magnetic substance disposed on the clamper to generate an attraction with respect to the magnet so that the clamper clamps the disk to the turntable by the attraction, the clamper rotatably contacting the holder unit when the disk is clamped.  
         [0020]     Additional aspects and/or advantages of the invention will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the invention. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0021]     These and/or other aspects and advantages of the invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings, of which:  
         [0022]      FIGS. 1A and 1B  are cross-section views showing a conventional disk chucking apparatus before chucking and after chucking, respectively;  
         [0023]      FIG. 2  is a top view showing a disk loading apparatus according to an embodiment of the present invention;  
         [0024]      FIG. 3  is an exploded perspective view showing the disk chucking apparatus of  FIG. 2 ; and  
         [0025]      FIGS. 4 and 5  are cross-section views taken along lines IV-IV of  FIG. 3  to explain the operation of chucking a disk according to an embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0026]     Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described to explain the present invention by referring to the figures.  
         [0027]     Referring to  FIG. 2 , the disk loading apparatus according to an embodiment of the present invention has a main chassis  100 , a first slider  110  and a second slider  112 , a connection member  114 , and a chucking apparatus  200 .  
         [0028]     The first and the second sliders  110  and  112  are disposed on opposite sides of the main chassis  100 , and move forwardly and backwardly. The connection member  114  connects the first and the second sliders  110  and  112 , and is rotatably supported by a hinge portion  102  provided on the main chassis  100 . When the first slider  110  receives a driving force from a driving motor (not shown) and reciprocates on the main chassis  100 , the connection member  114  moves the second slider  112  in relation to the movement of the first slider  110 , in the same direction the movement of the first slider  110 .  
         [0029]     The chucking apparatus  200  is disposed on the main chassis  100 . The chucking apparatus  200  has cam pins  214  inserted into cam recesses (not shown) formed in the first and the second sliders  110  and  112 . The cam pins  214 , which are inserted into the cam recesses, move in relation to a loading or unloading movement of the first and the second sliders  110  and  112 , so that a holder unit  210  (see  FIG. 3 ) and a clamper unit  250  (see  FIG. 3 ) of the chucking apparatus  200  ascend or descend on an upper portion of the main chassis  100 .  
         [0030]      FIG. 3  is an exploded perspective view showing the disk chucking apparatus and  FIG. 4  is a cross section view taken along line IV-IV of  FIG. 3 . Referring to  FIGS. 3 and 4 , the disk chucking apparatus has a turntable  290 , the holder unit  210 , and the clamper unit  250 .  
         [0031]     The turntable  290  rotates together with a disk D loaded thereon, and is driven by a spindle motor  294  mounted on the main chassis  100  (see  FIG. 2 ).  
         [0032]     An annular magnet  292  is press-fitted or caulked onto the turntable  290 .  
         [0033]     The holder unit  210  is disposed on the main chassis  100  and is ascendable and descendible. The holder unit  210  supports the clamper unit  250  so that the clamper unit  250  is attachable to and separable from the turntable  290 . The holder unit  210  includes a holder plate  212  and a plate spring  230  acting as a pressing member.  
         [0034]     The holder plate  212  is provided with cam pins  214 , plate spring connection holes  218 , plate spring support projections  216 , and a middle hole  220 . Two pairs of the cam pins  214  are provided at opposite sides of the holder plate  212 . The cam pins  214  are inserted into the cam recesses (not shown) so that the holder plate  212  ascends and descends in relation to the movements of the first and the second sliders  110  and  112  (see  FIG. 2 ). Two pairs of the connection holes  218  are defined in the holder plate  212  symmetrically with respect to the middle portion of the holder plate  212 . The plate spring support projections  216  are positioned over the connection holes  218 . The plate spring support projections  216  may be integrally formed with the holder plate  212  or attached to the holder plate  212  by welding. The middle hole  220  is defined in the middle portion of the holder plate  212 . The plate spring  230  is connected with the clamper unit  250  through the middle hole  220 . According to one embodiment, the holder plate  212  and the plate spring  230  are integrally formed.  
         [0035]     When a clamper  252  of the clamping unit  250  clamps the disk D, the plate spring  230  presses the clamper unit  250 , thereby preventing a wobble from being caused by an eccentric rotation of the disk D. The plate spring  230  is provided with connection pieces  232  and support pieces  234 . Two pairs of the connection pieces  232  are formed at opposite ends of the plate spring  230 . The connection pieces  232  downwardly bend from the plate spring  230  and are inserted into the connection holes  216  provided in the holder plate  212 . According to one embodiment, two support pieces  234  are separated from each other by a predetermined distance, and are oppositely disposed with respect to the middle portion of the plate spring  230 . Each support piece  234  downwardly bends from the plate spring  230  to support the clamper unit  250 . The plate spring  230  presses the clamper  252  and may use a coil spring for pressing the clamper  252 .  
         [0036]     When clamping the disk D, the clamper unit  250  has a bottom thereof press-contact the disk D and rotates together with the disk D. The clamper unit  250  includes the clamper  252  and a magnetic substance  270 .  
         [0037]     The clamper  252  includes an upper flange part  254 , a lower flange part  258 , a connection part  256 , a plate spring contact part  264 , and a magnetic substance mounting part  260 . The upper flange part  254  is formed on an upper portion of the clamper  252  and has an annular shape. The upper flange part  254  is supported on the support piece  234  of the plate spring  230 . The lower flange part  258  is formed on a lower portion of the clamper  252  and has an annular shape. The lower flange part  258  has a larger diameter than the upper flange part  254 . A lower surface of the lower flange part  258  contacts the disk D when clamping the disk D, and has a hole  259  defined in a center thereof corresponding to the turntable  290 , to allow the turntable  290  to be inserted therethrough. The connection part  256  connects the upper flange part  254  and the lower flange part  258 .  
         [0038]     The contact part  264  is shaped in a hemisphere that protrudes from the center of the clamper  252 . According to one embodiment, since the contact part  264  has a hemisphere shape, it is brought into point-contact with the plate spring  230 . The point-contact allows the plate spring  230 , which is fixed to the holder plate  212  to press the rotating clamper  252 . The contact part  264  may be dome-shaped, or may take various configurations if it is made of a material having low friction.  
         [0039]     The magnetic substance mounting part  260  is depressed in an annular shape with respect to the contact part  264 . Due to this shape, the magnetic substance  270  can be mounted on the magnetic substance mounting part  260  without increasing the height of the clamper  252 . The magnetic substance mounting part  260  has a connection protrusion  262  to be engaged with the magnetic substance  270 . According to one embodiment, the connection protrusion  262  is formed in a “         ” shape, and there are three connection protrusions  262  formed at a predetermined interval along a radial direction. The number of connection protrusions  262  increases or decreases depending on the size or thickness of the magnetic substance  270 . The connection protrusion  262  has an insert protrusion  262   a  and a locking protrusion  262   b . The insert protrusion  262   a  protrudes toward a center of the magnetic substance mounting part  260 , and the locking protrusion  262   b  downwardly protrudes from an end of the insert protrusion  262   a.    
         [0040]     The magnetic substance  270  generates a magnetic attraction with respect to the magnet  292  disposed on the turntable  290 , thereby allowing the clamper  252  to press the disk D. The magnetic substance  270  has an annular shape so that it is mounted on the magnetic body mounting part  260 . The magnetic substance  270  has three connection recesses  272  formed therein to be connected with the connection protrusions  262 . Each connection recess  272  is divided into an insert part  272   a  and a locking part  272   b.    
         [0041]     The insert part  272   a  is formed toward a center portion of the magnetic substance  270 . The insert protrusion  262   a  of the connection protrusion  262  is inserted into the insert part  272   a  when the magnetic substance  270  is mounted on the magnetic substance mounting part  260  downwardly. The locking part  272   b  is formed from an end of the insert part  272   a  in a radial direction of the magnetic substance  270 . The locking protrusion  262   b  of the connection protrusion  262  is locked into the locking part  272   b  when the magnetic substance  270  rotates after the insert protrusion is inserted into the insert part  272   a . Accordingly, by simply rotating the magnetic substance  270 , the magnetic substance  270  is securely mounted on the magnetic substance mounting part  260 .  
         [0042]     Hereinafter, operation of the disk chucking apparatus according to an embodiment of the present invention will now be described.  
         [0043]      FIG. 4  is a cross-section view showing the clamper and the disk before chucking, and  FIG. 5  is a cross-section view showing the clamper and the disk after chucking. Referring to  FIGS. 4 and 5 , the first and the second sliders  110  and  112  (see  FIG. 2 ) slide on the main chassis  100  (see  FIG. 2 ). In relation to the sliding movements of the first and the second sliders  110  and  112 , the holder plate  212  descends. At the same time, the plate spring  230  disposed on the holder pate  212  and the clamper  252  having the upper flange part  254  supported on the support pieces  234  descend. As the holder plate  212  and the plate spring  230  descend by a predetermined distance, the clamper  252  is brought into contact with the disk D so that the disk D is seated on the turntable  290 . After that, the holder plate  212  and the plate spring  230  further descend and the plate spring  230  presses the contact part  264 . At this time, as the plate spring  230  descends, the support pieces  234  of the plate spring  230  are positioned between the upper flange part  254  and the lower flange part  258  of the clamper  252 . That is, the support pieces  234  do not contact the clamper  252 , so that the clamper  252  can be rotated.  
         [0044]     When the chucking operation is completed as described above, the clamper  252  presses the disk D onto the turntable  290  due to a magnetic attraction exerted between the magnetic substance  270  and the magnet  292  and a pressure of the plate spring  230  exerted to the contact part  264 . After that, when the turntable  290  is rotated by the spindle motor  294 , the disk D and the clamper  252  are rotated. Also, since the contact part  264  of the clamper  252  point-contacts the plate spring  230 , the clamper  252  can be rotated in a state that the plate spring  230  is fixed to the holder plate  212 . As described above, the clamper  252  is rotated while pressing the disk D, thereby preventing a wobble from being caused by an eccentric rotation of the disk D.  
         [0045]     As noted previously, the conventional disk chucking apparatus has to use a magnet having a high magnetic force to prevent the wobble of the disk D. In contrast, according to an embodiment of the present invention, since the clamper  252  presses the disk D with the pressure of the plate spring  230  and the magnetic attraction, the magnet is not required to have a high magnetic force.  
         [0046]     To release from the chucking state, the driving motor (not shown) is rotated in a reverse direction to that of the above loading process. When the first and the second sliders  210  and  212  (see  FIG.2 ) move on the main chassis  100  (see  FIG. 2 ) in an unloading direction, the holder plate  212  ascends in relation to the sliding movements of the first and the second sliders  210  and  222  and the plate spring  230  ascends together with the holder plate  212 . As the support pieces  234  of the plate spring  230  ascend, they raise the upper flange part  254  of the clamper  252 , thereby distancing the clamper  252  from the disk D and the turntable  290 . At this time, the clamper  252  must overcome the magnetic attraction exerted between the magnetic substance  270  and the magnet  292  to ascend. Differently from the conventional apparatus, since the plate spring  230  presses the clamper  252 , the magnet  292  is not required to have a high magnetic force. Accordingly, the magnetic force that must be overcome to distance the clamper  252  from the disk D and the turntable  290  can be reduced, and thus a load generated in releasing the disk D from the chucking state can be reduced.  
         [0047]     In contrast to the conventional disk chucking apparatus, in the disk chucking apparatus  200 , since the magnet  290  is disposed on the turntable  290 , the height of the clamper  252  can be reduced. Accordingly, a compact-sized disk player or a slim type disk player can be realized.  
         [0048]     As described above, due to the presence of the plate spring  230 , a clamping force sufficient to prevent the wobble is generated, and a magnet having a reduced magnetic force can be employed. And thus, a load generated in releasing the disk from the chucking state can be reduced.  
         [0049]     Also, since the magnet  292  is disposed on the turntable  290 , the height of the clamper  252  can be reduced, and thus, the compactness and slimming of the disk player can be achieved.  
         [0050]     Although a few embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.

Technology Classification (CPC): 6