Abstract:
An optical disc drive ( 99 ) includes a frame ( 2 ); a U-shaped subframe ( 4 ) pivotably mounted on the frame; a slider ( 3 ) slidably mounted on the frame for making the subframe pivot; a drive unit ( 5 ) including a spindle motor ( 52 ) for rotating an optical disc, an optical pickup ( 53 ), and a feeding mechanism ( 54 ) adapted to move the optical pickup for reading/recording information; and a pair of elastic elements ( 45 ) located between the subframe and the drive unit for reducing vibration thereof.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention generally relates to an optical disc drive which can effectively reduce the vibration and noise produced by a drive unit thereof.  
         [0003]     2. Description of Related Art  
         [0004]     Optical disc drives are widely used in personal computers and in entertainment equipment such as DVD (Digital Video Disc) players. Generally, an optical disc received inside an optical disc drive is rotated by a drive unit, and an optical pick-up device moves along the radial direction of the optical disc to read a data stream recorded therein. If the optical disc does not rotate evenly, the optical disc drive is liable to vibrate and generate noise. Excessive vibration may even interfere with the correct operation of the optical pick-up. Therefore, measures must be taken to efficiently reduce the vibration of the drive unit.  
         [0005]     A typical example of a vibration-reducing configuration is disclosed in U.S. Pat. No. 4,922,478. Supporting elements are provided and arranged to reduce vibration of the drive unit in an optical disc drive. The supporting elements have helical springs. The springs elastically support the drive unit, reduce the vibration of the drive unit, and reduce noise accordingly. However, the supporting elements are only used to reduce vibration in vertical directions, and are not capable of reducing vibration in horizontal directions. The drive unit is liable to vibrate in horizontal directions. This not only produces noise, but may even lead to the optical disc being damaged.  
       SUMMARY OF THE INVENTION  
       [0006]     Accordingly, an object of the present invention is to provide an optical disc drive which can reduce vibration of a drive unit thereof in horizontal directions, and thereby effectively reduce or eliminate associated noise.  
         [0007]     Another object of the invention is to provide an optical disc drive which reduces vibration between a subframe and a frame thereof, especially during loading and unloading of an optical disc.  
         [0008]     In order to achieve the objects set out above, an optical disc drive of the present invention comprises: a frame; a U-shaped subframe pivotably mounted on the frame; a slider slidably mounted on the frame for making the subframe pivot; a drive unit comprising a spindle motor for rotating an optical disc, an optical pickup, and a feeding mechanism adapted to move the optical pickup for reading/recording information; and a pair of elastic elements located between the subframe and the drive unit for reducing vibration thereof.  
         [0009]     Other objects, advantages and novel features of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings, in which:  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]      FIG. 1  is an exploded, isometric view of an optical disc drive in accordance with the present invention;  
         [0011]      FIG. 2  is similar to  FIG. 1 , but viewed from another aspect;  
         [0012]      FIG. 3  is a further exploded view of  FIG. 2 , but not showing a tray of the optical disc drive;  
         [0013]      FIG. 4  is an enlarged view of a circled portion IV of  FIG. 3 ;  
         [0014]      FIG. 5  is similar to  FIG. 3 , but viewed from another aspect; and  
         [0015]      FIG. 6  is a cross-sectional view taken along line VI-VI of  FIG. 1 . 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0016]     Reference will now be made to the drawing figures to describe the preferred embodiment of the present invention in detail.  
         [0017]     As shown in  FIG. 1 , an optical disc drive  99  in accordance with the present invention includes a tray  1 , a frame  2 , a slider  3 , a U-shaped subframe  4 , a drive unit  5  and four dampers  6 . The tray  1  can slide into and out from the frame  2 .  
         [0018]     Referring to  FIGS. 2 and 3 , the drive unit  5  has a supporting plate  51 , a spindle motor  52 , an optical pickup  53  and a feeding mechanism  54 . An optical disc (not labeled) is rotated by the spindle motor  52 , and the optical pickup  53  is driven by the feeding mechanism  54  to move along the radial direction of the optical disc so that it reads information recorded in the disc. Four open mounting holes  511  are defined in four comers of the supporting plate  51  respectively.  
         [0019]     Referring also to  FIGS. 5 and 6 , the frame  2  is rectangular and hollow. The frame  2  comprises a pair of opposite side walls  21 , which are interconnected by a front beam  22  and by a back beam  23 . A U-shaped recess  211  is defined in a middle of each side wall  21 . An elastic arm  212  is formed on each side wall  21  at each recess  211 . The elastic arm  212  extends from an outer side of the recess  211  into the recess  211 . The elastic arm  212  comprises a fixed portion  213  and a movable portion  214 . The movable portion  214  comprises a claw  215  at an upper end thereof. A first elastic sponge  25  is fixed at each of junctions of the front beam  22  and the two side walls  21  (see especially  FIG. 4 ). A platform  24  is formed at each of junctions of the back beam  23  and the two side walls  21 . A screw hole  241  is defined in each platform  24 .  
         [0020]     The slider  3  is movably mounted on the front beam  22  of the frame  2 . Two parallel Z-shaped slots  31  are defined in the front beam  22 . Each Z-shaped slot  31  comprises a higher slot portion  311 , a lower slot portion  312 , and a slant slot portion  313  intercommunicating between the higher slot portion  311  and the lower slot portion  312 .  
         [0021]     The U-shaped subframe  4  comprises a crossbeam  41 , two parallel side beams  42  connecting with opposite ends of the crossbeam  41  respectively, and two extended ends  43  extending perpendicularly outwardly from the free ends of the side beams  42  respectively. The extended ends  43  are accommodated in the recesses  211 . Each extended end  43  comprises a cylindrical pivot portion  431 , and a cylindrical clamping portion  432  at a distal end of the pivot portion  431 . A cross section of the clamping portion  432  is larger than that of the pivot portion  431 . Two guide pins  411  extend from an outside surface of the crossbeam  41 , for being slidably received in the Z-shaped slots  31  of the slider  3 . A platform  44  is formed at each of junctions of the crossbeam  23  and the two side beams  42 . A screw hole  441  is defined in each platform  44 . A second elastic sponge  45  is fixed on an inside surface of each side beam  42 .  
         [0022]     The dampers  6  are made of elastic rubber. Each damper  6  defines a central through hole  62 , and an external annular groove  61 . The annular groove  61  enables the damper  6  to be deformably accommodated in a corresponding mounting hole  511 .  
         [0023]     In assembly of the optical disc drive  99 , the guide pins  411  of the U-shaped subframe  4  are inserted into the Z-shaped slots  31 . The extended ends  43  of the U-shaped subframe  4  are pivotably mounted to the frame  2 . In particular, the pivot portions  431  of the extended ends  43  are received in the recesses  211 , and the claws  215  of the elastic arms  212  hold the extended ends  43  and prevent the extended ends  43  from accidentally coming out from the recesses  211 . Further, the elastic arms  212  clamp the clamping portions  432 , thereby preventing the U-shaped subframe  4  from moving in directions parallel to the crossbeam  41 . The dampers  6  are deformably engaged in the mounting holes  511  of the supporting plate  51 . Four screw bolts  7  are respectively passed through the through holes  62  of the dampers  6  and engaged in the screw holes  441  of the U-shaped subframe  4  and the screw holes  241  of the frame  2 . Thus, the front of the drive unit  5  is fixed on the platforms  44  of the U-shaped subframe  4 , and the back of the drive unit  5  is fixed on the platforms  24  of the frame  2 . As a result, the drive unit  5  is located between the second sponges  45  of the side beams  42 . Lastly, the tray is inserted into the frame  2 .  
         [0024]     In operation, the slider  3  slides left/right along the front beam  22  as the tray  1  slides into/out from the frame  2 . When the slider  3  slides to the left end of the front beam  22  (as viewed from a front of the optical disc drive  99 ), the pins  411  of the U-shaped subframe  4  are in the lower slot portions  312 . Conversely, when the slider  3  slides to the right end of the front beam  22  (as viewed from the front of the optical disc drive  99 ), the guide pins  411  of the U-shaped subframe  4  slide along the Z-shaped slots  31  into the higher slot portions  311 . As the slider  3  moves from left to right and from right to left, the U-shaped subframe  4  can pivot about the extended ends  43  correspondingly. That is, the drive unit  5  can rise or fall together with the U-shaped subframe  4 . The first elastic sponges  25  at the junctions of the front beam  22  and the side walls  21  reduce the clearance between the U-shaped subframe  4  and the frame  2 . The first elastic sponges  25  thus reduce any vibration of the U-shaped subframe  4 , especially during loading and unloading of the optical disc. The dampers  6  can reduce the vibration of the drive unit  5  in vertical directions. The second elastic sponges  45  can reduce the vibration amplitude of the drive unit  5  in horizontal directions, thus reducing any noise caused by vibration of the drive unit  5 .  
         [0025]     In alternative embodiments, the first elastic sponges  25  can instead be attached on the U-shaped subframe  4 . As long as the first elastic sponges  25  are placed between the U-shaped subframe  4  and the frame  2 , vibration occurring during loading and unloading of the optical disc can be reduced. Similarly, the second elastic sponges  45  can instead be attached on side surfaces of the drive unit  5 . As long as the second elastic sponges  45  are placed between the U-shaped subframe  4  and the drive unit  5 , vibration of the drive unit  5  can be reduced. Furthermore, the first elastic sponges  25  and the second elastic sponges  45  can be devices or materials other than elastic rubber. For example, the first and second elastic sponges  25 ,  45  may instead be springs, or may comprise another kind of elastic material such as an elastomer.  
         [0026]     Although the present invention has been described with reference to specific embodiments, it should be noted that the described embodiments are not necessarily exclusive, and that various changes and modifications may be made to the described embodiments without departing from the scope of the invention as defined by the appended claims.