Abstract:
A disk drive including a lower case, a tray to be attached and detached to and from the lower case while sliding in the lower case and having a turntable on which a disk is seated, and an upper case installed to cover an upper portion of the lower case. The upper case has at least one deviation-prevention element extending toward the lower case to prevent the disk from deviating from the turntable by an external force on the disk drive by reducing a distance between the upper case and the disk seated on the turntable.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
   This application claims the priority of Korean Patent Application No. 2004-28471, filed on Apr. 24, 2004, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference. 
   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a disk drive, and more particularly, to a disk drive capable of preventing a disk from deviating from a turntable by an external force and capable of preventing damage to a movable tray holding the disc. 
   2. Description of the Related Art 
   In general, a disk drive is a device which reproduces information stored on a disk or records the information to the disk while sliding an optical pickup unit in a radial direction of the disk. 
   The disk drive used in an information device such as a notebook is necessarily manufactured in a thin form due to its characteristics. Thus, the height or width of the disk drive is limited to a predetermined size. 
     FIG. 1  is an exploded perspective view of a conventional disk drive,  FIG. 2  is a cross-sectional view of the disk drive of  FIG. 1 , and  FIG. 3  is a plan view of a cut stopper. 
   The disk drive of  FIG. 1  includes a lower case  10 , an upper case  30  which covers the lower case  10 , and a tray  20  which slides in the lower case  10  and on which a disk D is seated (see  FIG. 2 ). 
   The tray  20  includes a turntable  22  on which the disk D is seated, a spindle motor  24  (see  FIG. 2 ) which is installed on the same axis as that of the turntable  22  and which rotates the turntable  22 , and a base frame  21  having an optical pickup unit  23  which slides in a radial direction of the disk D and reproduces information stored on the disk D or records the information on the disk D. 
   The tray  20  is guided on guide rails  13  installed at both sides of the lower case  10 . A guide unit  11  is installed to on both sides of the tray  20  and to slide relative to the guide rails  13 , and is attached and detached to and from the lower case  10 . 
   A stopper  12  is formed in a portion of the guide unit  11  and protrudes from an inside of the lower case  10  or the tray  20 . A protrusion  14  is formed in a portion of one of the guide rails  13  catches the stopper  12  to restrict a moving distance of the tray  20  when the tray  20  is moved out of the lower case  10 . A spacing portion  15  is placed between the lower case  10  and the guide unit  11 . The spacing portion  15  is a necessary portion to assist in inserting the guide rails  13  in the lower case  10  during assembly. 
   However, as shown in  FIG. 3 , when the tray  20  is moved out of the lower case  10 , the protrusion  14  collides with the stopper  12  and the stopper  12  may be cut by a collision shock. Specifically, when an external force is applied to the tray  20  in an X-direction ( FIG. 1 ), the tray  20  is opened in the X-direction, the protrusion  14  collides with the stopper  12  and does not survive the external force, and damage occurs in the guide unit  11  in the direction of the spacing portion  15 . 
   Meanwhile, referring to  FIG. 2 , a distance G 1  is formed between the disk D mounted on the turntable  22  and the upper case  30 . The distance G 1  is optimized for operation of the disk drive, and is difficult to change. 
   When an operating shock occurs in a Z-direction ( FIG. 1 ) while the disk drive is in the lower case  10 , the disk D clamped in the turntable  22  does not survive the operating shock and may deviate from the turntable  22 . In this case, an information recording surface may be damaged, information may be lost, and the disk D may be held in the disk drive such that the tray  20  is not easily opened. 
   SUMMARY OF THE INVENTION 
   Accordingly, it is an aspect of the present invention to provide a disk drive capable of preventing a disk from deviating from a turntable by an external force and having a guide unit that endures an external shock when a tray is moved out of a lower case. 
   Additional aspects and/or advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention. 
   The forgoing and/or other aspects are achieved by providing a disk drive including a lower case; a tray to slide in the lower case, including a turntable on which the disk is seated; and an upper case to cover an upper portion of the lower case and having a deviation-prevention element protruding towards the lower case and preventing the disk from being deviated from the turntable by an external force by reducing a distance between the upper case and the disk. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above and/or other aspects and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which: 
       FIG. 1  is an exploded perspective view of a conventional disk drive; 
       FIG. 2  is a cross-sectional view of the disk drive of  FIG. 1 ; 
       FIG. 3  is a plan view of a cut stopper of  FIG. 1 ; 
       FIG. 4  is an exploded perspective view of a disk drive according to an embodiment of the present invention; 
       FIG. 5  is a partial enlarged view of a portion of a lower case of  FIG. 4 ; 
       FIG. 6  is a cross-sectional view of the disk drive of  FIG. 4 ; 
       FIG. 7  is a plan view of a deviation-prevention element according to an embodiment of the present invention; 
       FIG. 8  is a cross-sectional view taken along line I-I′ of  FIG. 7 ; 
       FIG. 9  is a plan view of a deviation-prevention element according to another embodiment of the present invention; and 
       FIG. 10  is a cross-sectional view taken along a line II-II′ of  FIG. 9 . 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. The embodiments are described below to explain the present invention by referring to the figures. 
   Referring to  FIG. 4 , a disk drive includes a lower case  100 , an upper case  130  which covers the lower case  100 , and a tray  120  which is installed to slides in the lower case  100  and on which a disk D is seated. 
   The tray  120  includes a turntable  122  on which the disk D is seated, a spindle motor  124  (see  FIG. 6 ) which is installed on the same axis as the turntable  122  and which rotates the turntable  122 , and a base frame  121  having an optical pickup unit  123  which is installed to slides in a radial direction of the disk D and reproduces information stored on the disk D or records the information to the disk D. 
   Guide rails  113  are installed at both sides of the tray  120 , and a protrusion  114  is formed in a portion of one of the guide rails  113  and protrudes upwards, that is, toward the upper case  130 . 
   Referring to  FIG. 5 , a guide unit  111  is installed at both sides of the lower case  100 . The guide rails  113  are inserted into the guide unit  111 , and the guide unit  111  guides the guide rails  113  to slide. A stopper  112  is formed in the guide unit  111  corresponding to the guide rails  113  in which the protrusion  114  is formed. The stopper  112  protrudes from a direction in which the guide rails  113  face each other. A spacing portion  117  is placed between the lower case  100  and the guide unit  111 . 
   A portion  111   a  of the guide unit  111  having the stopper  112  is thinner than other portions of the guide unit  111  so as to form the spacing portion  117  separated from the lower case  100  by a predetermined distance. Thus, the portion  111   a  itself has an elastic force and can be elastically deformed. The portion  111   a  is elastically deformed when the guide rails  113  are assembled in the guide unit  111  such that the stopper  112  is prevented from being caught on the protrusion  114  and the spacing portion  117  is formed in the portion  111   a  for ease of assembly. 
   A reinforcement unit  116  is formed on an opposite side of the portion  111   a  having the stopper  112  to protrude from the spacing portion  117 . The length L (the length in which the tray  120  is attached and detached to and from the lower case  100 ) of the reinforcement unit  116  may be larger than the length I of the stopper  112 . In addition, the reinforcement unit  116  may be formed so that the length L of the reinforcement unit  116  is greater than the length I of the stopper  112  and the lengths L and I overlap each other. 
   Thus, the stopper  112  alleviates the concentration of stress where it is connected to the guide rails  113  so that the stopper  112  is prevented from being damaged by a shock against the protrusion  114 . The reinforcement unit  116  may have a variety of shapes that maintain its function. 
   In the above structure, the tray  120  is attached and detached to and from the lower case  100  as the guide rail  113  slides along the guide unit  111 . When the tray  120  is removed from the lower case  100 , the protrusion  114  collides with the stopper  112  and is stopped. 
   Referring to  FIGS. 4 and 6 , a deviation-prevention element  131  is formed in the upper case  130  and protrudes from a direction opposite to the lower case  100 , that is, to face the disk D seated on the turntable  122 . 
   The deviation-prevention element  131  faces a noninformation area of the disk D, that is, an inside (a circumference of a portion seated on the turntable  122 ) of the disk D. This prevents information stored on the disk D from being damaged by a collision caused by an external shock applied to the deviation-prevention element  131 . 
   The deviation-prevention element  131  is not formed in an area in which the tray  120  is attached and detached to and from the lower case  100  and also faces the noninformation area of the disk D, so as not to interfere with an operation of attaching and detaching the tray  120  to and from the lower case  100 . The deviation-prevention element  131  has a U-shape, but is not limited to this shape and may have a variety of shapes in which the deviation-prevention element  131  faces the noninformation area of the disk D, excluding the direction in which the tray  120  is attached and detached to and from the lower case  100 . 
   The deviation-prevention element  131  may be formed as one piece with the upper case  130 . 
   A distance G 2  between the deviation-prevention element  131  and the disk D is smaller than a distance G 1  (see  FIG. 2 ) between the upper case  130  and the disk D so that the deviation-prevention element  131  prevents the disk D from being detached from the turntable  122  by an external shock. 
   Referring to  FIGS. 7 and 8 , a plurality of deviation-prevention elements  231  protrudes from an upper case  230  (similar to the upper case  130 ) to face the disk D seated on the turntable  122 . In addition, the deviation-prevention elements  131  face a noninformation area of the disk D, that is, an inside of the disk D. The deviation-prevention elements  231  can again be formed as one body with the upper case  230 . 
   The operation of the deviation-prevention element  231  is similar to that of the deviation-prevention element  131  of  FIGS. 4 and 6  and thus, detailed descriptions thereof will be omitted. 
   Referring to  FIGS. 9 and 10 , a deviation-prevention element  331  is formed by attaching an adhesion sheet having a predetermined thickness to a bottom surface of an upper case  330  (similar to the upper case  130 ). In this case, even though the deviation-prevention element  331  is not formed as one body with the upper case  330 , the deviation-prevention element  331  may easily be installed in a disk drive for ease of manufacture. The operation of the deviation-prevention element  331  is similar to that of the deviation-prevention element  131  of  FIGS. 4 and 6  and thus, detailed descriptions thereof will be omitted. 
   As described above, in the disk drive according to the embodiments of the present invention, a disk is prevented from being deviated from a turntable by an external force, and even though an external shock is applied to a direction in which a tray is opened, a guide unit survives the external shock and is not damaged. 
   While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention, as defined by the following claims.