Abstract:
An ESD protection device for a disk drive comprises a guide at two inner sides of the disk drive. A conductive sponge, one end contacting the case and the other protruding end contacting one of two conductive rails, is disposed in one guide. A hook is formed at one end, jutting out of the disk drive, of the rail. The rails support two sides of the tray, having electric elements disposed thereon and its bottom being covered by a conductive traverse cover, sliding. A conductive elastic stopper disposed at the bottom tray has an indentation formed at the front end to position the hook on the indentation&#39;s moving path, a contact part bent to electronically connect to the cover next to the indentation, and a sliding part formed at the rear end by protruding upwards to electronically connected to the rail, to electronically connect to the cover and the rail.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The invention relates in general to an optical disk drive, and more particularly to an electrostatic discharge protection device for eliminating static electricity from users so as not to harm precision electrical components in an optical disk drive. 
         [0003]    2. Description of the Related Art 
         [0004]    In the process of operating an optical disk drive having precision electrical components, users have to contact the optical disk drive. Thus, the static electricity form the users accumulates in conductors or rushes everywhere through the conductors in the optical disk drive. Once the static electricity is transmitted to the precision electrical components, the electrical components are destructible easily. 
         [0005]      FIG. 1  is a perspectively top view of the inside of a conventional optical disk drive  10 .  FIG. 2  is a perspectively bottom view of the inside of the conventional optical disk drive  10 . A metallic case  11  has a hollow space, and two fixing guides  111  made of plastic material are disposed at two sides of the case  11  respectively. A metallic rail  112  is slidably disposed in each fixing guide  111 . One end of the rail  112  is obstructed by an obstructive lump  113  of the case  11 , and the other end of the rail  112  supports two sliding sticks  121  of a tray  12  at two sides. A hook  114  is disposed in one of the rail  112  for blocking a blocking lump  122  located at the rear end of the tray  12  and restricting the distance that the tray  12  jutting out of the case  11 . Thus, the tray  12 , comprised of plastic, could slide inwards and outwards the case  11  and jut out of the case  11  completely. Moreover, the precision electrical components, such as a spindle motor  13  for rotating a disk or a pickup head  14 , are disposed on the tray  12 , and the bottom of the tray  12  is covered and protected by a traverse cover  15 , which is metal. The front end of the tray  12  connects with a panel  16  having an eject key  17 . One end of a flexible flat cable  18  of a print circuit board connects with a main circuit board  19  and is disposed close to the inner surface of the case  11 . The other end of the flexible flat cable  18  is movable, connects with the rear end of the tray  12 , and is electronically connected to the traverse cover  15 . One circuit line of the flexible flat cable  18  and the case  11  are grounded. 
         [0006]    When users eject disks by pressing the eject key  17 , the static electricity form the users is transmitted to the traverse cover  15  which is metal via the gap between the panel  16  and the eject key  17 . Or, when users directly touch the optical disk drive  10 , the static electricity is directly transmitted to the traverse cover  15  which is metal, and then the static electricity is eliminated by being transmitted from the flexible flat cable  18  to the case  11 . However, though little static electricity can be eliminated, a great quantity of unexpected static electricity may not be eliminated rapidly due to the small size of the flexible flat cable  18 . In that situation, the accumulation of static electricity causes destruction. Additionally, if a great quantity of static electricity passes through the flexible flat cable  18  which is used for transmitting signal and data, the signal and data being transmitted at the same time are interfered easily. Consequently, the reliability of the optical disk drive is affected. Furthermore, the hook  114  disposed in the rail  112  which is comprised of thin metal harms the blocking lump  122  which is comprised of plastic when the hook  114  obstructs the blocking lump  122 , especially when suffering a great bump. Accordingly, the tray may lock with the rail and thus be unable to eject disks and insert disks normally. Hence, the problems of the electrostatic discharge protection and the breaking of the tray in the conventional optical disk drive need to be solved. 
       SUMMARY OF THE INVENTION 
       [0007]    It is therefore an object of the invention to provide an electrostatic discharge protection device for an optical disk drive, in which a conductive elastic stopper electrically connected to a traverse cover and a rail is utilized for grounding the static electricity through the rail, so as to avoid the static electricity interfering the transmission of signal and data. 
         [0008]    It is therefore another object of the invention to provide an electrostatic discharge protection device for an optical disk drive, that enhances the breaking strength when suffering a bump by utilizing an elastic stopper as the blocking lump of the optical disk drive, so as to increase the reliability of the optical disk drive. 
         [0009]    It is therefore another object of the invention to provide an electrostatic discharge protection device for an optical disk drive, wherein the static electricity is grounded through the two sides of the rails and the accumulative static electricity on the rails is guided to be eliminated, so as to increase the efficacy of eliminating static electricity. 
         [0010]    According to a first aspect of the present invention, an electrostatic discharge protection device for an optical disk drive is provided. A guide is fixed at two sides of the inner case respectively. A conductive sponge is disposed in one of the guides. One end of the conductive sponge contacts the case, and the other end protruding from the guide contacts one of the conductive rails. A hook is formed at one end, which juts out of the optical disk drive, of the rail. The rails support two sides of the tray sliding. Electric elements are disposed on the tray which its bottom is covered and protected by a conductive traverse cover. An elastic stopper, being conductive, is disposed at the bottom of the tray and has an indentation at the front end for positioning the hook on the moving path of the indentation. A contact part located at the side of the indentation is bent to electronically connect to the traverse cover. The rear end of the elastic stopper protrudes upwards to form a sliding part electronically connected to the rail, so as to electronically connect the traverse cover and the rail. 
         [0011]    According to a second aspect of the present invention, another electrostatic discharge protection device for an optical disk drive is provided. The electrostatic discharge protection is disposed in a case of the optical disk drive. The bottom of a tray having electric elements disposed thereon is covered and protected by a conductive traverse cover. Two rails, being conductive and including a first rail and a second rail, are disposed at two sides of the case to support the tray sliding. A hook is formed at the end, where juts out of the optical disk drive, of the first rail. A first elastic stopper, being conductive, is electrically connected to the traverse cover and the first rail having the hook. An indentation is formed at the front end of the elastic stopper to position the hook on the moving path of the indentation. A second conductive elastic stopper is electrically connected to the traverse cover and the second rail. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0012]      FIG. 1  is a perspectively view of the inside of a conventional optical disk drive. 
           [0013]      FIG. 2  is a perspective view of the reverse side of the conventional optical disk drive. 
           [0014]      FIG. 3  is a perspective view of an electrostatic discharge protection device for an optical disk drive according to a preferred embodiment of the invention. 
           [0015]      FIG. 4  is a perspective view of the inner structure of the case with omitting a part. 
           [0016]      FIG. 5  is a perspective view of the first elastic stopper. 
           [0017]      FIG. 6  is a magnified figure of partial combination of the first elastic stopper. 
           [0018]      FIG. 7  is a magnified figure of a second rail. 
           [0019]      FIG. 8  is a perspective view of the second elastic stopper. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0020]    In order to achieve the purpose mentioned above, a preferred embodiment is detailedly described below. The invention will become apparent from the following detailed description of the preferred but non-limiting embodiments. The following description is made with reference to the accompanying drawings. 
         [0021]    Referring to  FIG. 3 , a perspective view of an electrostatic discharge protection device for an optical disk drive  20  according to a preferred embodiment of the invention is shown. The optical disk drive  20  includes a case  21 , a tray  22 , a first rail  23 , a second rail  24  and a flexible flat cable  25 . The first rail  23  and the second rail  24  are disposed at two sides of the case  21  to support the tray  21 , and the tray  21  is slidable with respect to the case  21  inwards and outwards. The flexible flat cable  25  connected with the tray  22  moves with the tray  22  and transmits data and signal. 
         [0022]    Referring to  FIG. 4 , a perspective view of the inner structure of the case  21  with omitting a part is shown. The case  21  is made of conductive material, such as metal. A first guide  211  and a second guide  212  are firmly disposed at two inner sides of the case  21  respectively. The first guide  211  and the second guide  212  are plastic. A conductive sponge  216  is disposed in each guide. One end of the conductive sponge  216  contacts with the case  21 , and the other end of the conductive sponge  216  protrudes from the first guide  211  and the second guide  212 . An obstructive lump  217  is respectively disposed next to the first guide  211  and the second guide  212  of the case  21 . A main circuit board  213  is disposed at the rear side of the case  21 . The rear end of the main circuit board  213  is connected to an outer connector  214  as a connecting interface with the external circuits. The front end of the main circuit board  213  is connected to an inner connector  215  for connecting with one end of the flexible flat cable  25 . A half flexible flat cable  25  leans against the bottom surface of the case  21  along the direction of the slot of the inner connector  215 , and another half flexible flat cable  25  is movable. 
         [0023]    Please also refer to  FIG. 3  at the same time. The first rail  23  and the second rail  24  are made of conductive material, such as metal. The first rail  23  and the second rail  24  are disposed in the first guide  211  and the second guide  212  respectively so as to be capable of moving along the rails unrestrictedly, and compress the conductive sponge  216  to form an electrical connection. One end of the first rail  23  and one end of the second rail  24  are obstructed by the obstructive lump  217  (not shown), and the other end of the first rail  23  and the other end of the second rail  24  are capable of jutting out of the case  21 . A hook  231  is formed near the other end of the first rail  23  which is capable of jutting out of the case  21 . 
         [0024]    Furthermore, the main body of the tray  22  is plastic. The front end of the tray  22  is connected to a panel  221  on which an eject key  222  is disposed. The bottom of the tray  22  is covered with a traverse cover  223  being made of conductive material, such as metal. The front end of the traverse cover  223  is connected with the panel  221  and close to the eject key  222 . Two sliding sticks  227  extending from two sides of the main body of the tray  22  are disposed in and supported by the first rail  23  and the second rail  24  so as to allow the tray  22  to be jutted out of the case  21 . The rear side of the tray  22  is connected with the underneath of movable end of the flexible flat cable  25 . At the bottom of the tray  22 , a fixing pillar  224  is disposed close to the rear end of the traverse cover  223  and the first rail  23 . A first elastic stopper  225  is fixed at the fixing pillar  224  by utilizing a screw  226 . 
         [0025]    Referring to  FIG. 5 , a perspective view of the first elastic stopper  225  is shown. The main body of the first elastic stopper  225  is a flake of conductive material, such as metal. An indentation  2251  is formed at the front end of the first elastic stopper  225 , and the portion next to the indentation  2251  is bent vertically downward to form a contact part  2252 . The middle of the first elastic stopper  225  is pierced through to form a screw hole  2253  and the rear end of the first elastic stopper  225  protrudes upwards to form a sliding part  2254 . The shape of a fixing side  2255  of the first elastic stopper  225  conforms to the shape of the fixing pillar  224 . Referring to  FIG. 6 , a magnified figure of partial combination of the first elastic stopper in  FIG. 4  is shown. When the first elastic stopper  225  is fixed firmly at the fixing pillar  224  by piercing through the screw hole  2253  with the screw  226 , the fixing side  2255  of the first elastic stopper  225  is wedged into the fixing pillar  224 . Thus, the first elastic stopper  225  renders incapability of rotating, so as to enhance the braking efficacy of the first elastic stopper  225 . Meanwhile, the contact part  2252  at the front end of the first elastic stopper  225  is against an extending part  2231  at the rear end of the traverse cover  223  to result in being electronically connected. The side of the first elastic stopper  225  opposite to the contact part  2252  extends into the first rail  23  to position the hook  231  on the moving path of the indentation  2251 , for obstructing the indentation  2251  and avoiding the tray  22  being deviate from the case  21 . The sliding part  2254  protruding upwards from the rear end of the first elastic stopper  225  is propped against and therefore electronically connected to the first rail  23 . The traverse cover  223  and the first rail  23  become a conductive loop by the connection of the first elastic stopper  225 . 
         [0026]    Additionally, referring to  FIG. 7 , a magnified figure of a second rail  24  in  FIG. 3  is shown. A second elastic stopper  229  is fixed firmly at the rear corner, which is close to the second rail  24 , of the traverse cover  223  by utilizing a fixing screw  228 . Please refer to  FIG. 8  at the same time, a perspective view of the second elastic stopper  229  is shown. The second elastic stopper  229  is a twisty bar spring of conductive material, such as metal. The middle of the second elastic stopper  229  is twisted to form a fixing hole  2291 . The second elastic stopper  229  is fixed firmly on the traverse cover  223  by the fixing screw  228  piercing through the fixing hole  2291 . One end of the second elastic stopper  229  is bent to form an U-shape end  2292  for wedging into and being electrically connected with the traverse cover  223 . The other end of the second elastic stopper  229  is formed an elastic clasp  2293  to prop against and be electrically connected with the second rail  24 . The traverse cover  223  and the second rail  24  become another conductive loop by the connection of the second elastic stopper. 
         [0027]    Please refer to  FIG. 3  and  FIG. 4  at the same time, when users eject disks by pressing the eject key  222 , the static electricity from the users is transmitted to the traverse cover  223  via the gap between the panel  221  and the eject key  222 . Then, the static electricity can be grounded and eliminated by the conductive loop of transmitting from the extending part  2231  at the rear end of the traverse cover  223  to the contact part  2252  of the first elastic stopper  225 , and then from the first rail  23  propped against the sliding part  2254  to the conductive sponge  216 , then to the case  21 . Or, the static electricity can be grounded and eliminated by the conductive loop of transmitting from the U-shape end  2292  of the second elastic stopper  229  to the second rail  24  propped against the elastic clasp  2293 , and then from the conductive sponge  216  to the case  21 . Thus, the electrostatic discharge protection device for an optical disk drive of the invention is achieved. 
         [0028]    In the electrostatic discharge protection device for an optical disk drive according to the above-described preferred embodiment of the invention, at least a conductive elastic stopper is electrically connected to the traverse cover and the rails, so that the static electricity can be grounded via the rails. Thus, the static electricity can be eliminated without passing through the flexible flat cable, so as to avoid the static electricity interfering the transmission of signal and data. In addition, a great quantity of static electricity can be eliminated due to more circuit lines of the flexible flat cable. Furthermore, in addition to being electrically connected to the traverse cover and the rails, the elastic stopper of the present invention can also be the blocking lump of the tray for enhancing the braking efficacy when the tray suffers a bump because of its metallic elasticity and toughness. Thus, it is capable of avoiding the deviate and harm of the tray, so as to eject disks and insert disks normally, hence the reliability of the optical disk drive is increased. Meanwhile, the electrostatic discharge protection device of the invention makes the rails at two sides become a link of the static electricity eliminating loop, hence the advantage of easy touch in operating is achieved. Besides, the accumulated static electricity can be grounded and eliminated by the metallic rails isolated by the plastic guides and the tray, hence the harm of the precision electrical components in the optical disk drive can be reduced. 
         [0029]    While the invention has been described by way of example and in terms of a preferred embodiment, it is to be understood that the invention is not limited thereto. On the contrary, it is intended to cover various modifications and similar arrangements and procedures, and the scope of the appended claims therefore should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements and procedures.