Abstract:
A tray for a disc drive includes a disc receiving region, a side wall substantially surrounding the disc receiving region, and a plurality of hooks extending inwardly from the side wall. The disc receiving region includes a first portion for receiving a disc, and one or more second portions. The hooks is spaced apart from the disc receiving region and spatially corresponding to the one or more second portions of the disc receiving region, and is for preventing the disc from being displaced from the disc receiving region.

Description:
BACKGROUND  
       [0001]     1. Field of the Invention  
         [0002]     The present invention generally relates to trays for disc drives, and particularly to a tray for a disc drive which can effectively reduce noise and vibration of an optical disc loaded on the tray when the optical disc rotates at high speed.  
         [0003]     2. Related Art  
         [0004]     Tray-loading type optical disc reading/playing (“reproducing”) devices typically include CD-ROM (compact disk-read only memory) drives, DVD-ROM (digital video disc-read only memory) drives and CD audio players. Referring to  FIG. 5 , this shows a loading tray  1   a  of a typical tray-loading type optical disc reproducing device, together with an optical disc  30   a.  In order to prevent the optical disc  30   a  from being detached from the loading tray  1   a  when the tray-loading type optical disc reproducing device is operated in a vertical orientation, a plurality of hooks  46   a  is provided on a peripheral portion  40   a  of an optical disc receiving region  20   a  of a main body  10   a  of the loading tray  1   a.    
         [0005]     Each hook  46   a  extends radially inwardly from the peripheral portion  40   a  of the disc receiving region  20   a.  In cases where the loading tray  1   a  is vertically oriented, the optical disc  30   a  received in the disc receiving region  20   a  may be retained by the hooks  46   a,  thereby preventing the optical disc  30   a  from detaching from the loading tray  1   a.    
         [0006]     Most trays for disc drives are made of a plastic material, such as ABS (Acrylonitrate-Butadiene-Styrene), PC (Polycarbonate), or a combination of ABS plus PC. Such trays are made by an injection molding process. In the case of the loading tray  1   a,  an upper mold and a lower mold of an injection mold interface along a path that is generally parallel to an upper surface of the main body  10   a.  In order to form the hooks  46   a  and allow easy separation of the upper mold from the lower mold along a single axis, a plurality of mold releasing holes  44   a  is defined in the disc receiving region  20   a  below the corresponding hooks  46   a.  To ensure that the hooks  46   a  are properly shaped, the mold releasing holes  44   a  are generally slightly larger than areas of horizontal portions of the hooks  46   a.  Thus when the injection mold is opened, upper mold is easily moved away from lower mold, and the loading tray la can be released from the lower mold by eject rods or an eject plate.  
         [0007]     As shown in  FIG. 6 , when the optical disc  30   a  is rotated at high speed by a spindle motor, a first airflow  300   a  flowing over the optical disc  30   a  and a second airflow  300   b  flowing under the optical disc  10   a  are produced. The first airflow  300   a  may generally flow smoothly over the optical disc  30   a.  Portions of the second airflow  300   b  exit through the mold releasing holes  44   a.  However, the mold releasing holes  44   a  are generally too small to allow the second airflow  300   b  to smoothly flow therethrough. That is, the second airflow  300   b  is retarded and generates turbulence at the mold releasing holes  44   a.  Thus noise is also generated. The turbulence may also cause the optical disc  10   a  to vibrate. All in all, the mold releasing holes  44   a  are prone to generate noise and vibration of the optical disc  10   a.    
         [0008]     Therefore, a heretofore unaddressed need exists in the industry to address the aforementioned deficiencies and inadequacies.  
       SUMMARY  
       [0009]     Briefly described, one embodiment of a tray for disc drive, among others, can be implemented as described herein.  
         [0010]     A tray for a disc drive includes a disc receiving region, a side wall substantially surrounding the disc receiving region, and a plurality of hooks extending inwardly from the side wall. The disc receiving region includes a first portion for receiving a disc, and one or more second portions. The hooks is spaced apart from the disc receiving region and spatially corresponding to the one or more second portions of the disc receiving region, and is for preventing the disc from being displaced from the disc receiving region.  
         [0011]     Other systems, methods, features, and advantages of the present invention will be or become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, features, and advantages be included within this description, be within the scope of the present invention, and be protected by the accompanying claims. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]     Many aspects of the invention can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present invention. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.  
         [0013]      FIG. 1  is an isometric view of a disc drive having a tray in accordance with a first preferred embodiment of the present invention, together with a disc.  
         [0014]      FIG. 2  is an isometric view of the tray of  FIG. 1  with the disc loaded thereon, but viewed from another aspect.  
         [0015]      FIG. 3  is a partial cross-sectional view of the tray and the disc, taken along line III-III of  FIG. 2 , showing different flow directions of a first airflow and a second airflow in operation.  
         [0016]      FIG. 4  is  FIG. 3 , but showing different flow directions of a first airflow and a second airflow in respect of a tray in accordance with a second preferred embodiment of the present invention.  
         [0017]      FIG. 5  is an isometric view of a conventional tray of an optical disc reproducing device, together with an optical disc.  
         [0018]      FIG. 6  is a partial cross-sectional view of the tray of  FIG. 5  with the optical disc loaded thereon, showing different flow directions of a first airflow and a second airflow in operation. 
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0019]     Reference will now be made to the drawing figures to describe the preferred embodiments of the present invention in detail.  
         [0020]     Referring to  FIG. 1 , this shows a disc drive having a loading tray in accordance with a first preferred embodiment of the present invention. The disc drive  2  includes the tray  1 , for carrying a disc  3  into or out from the disc drive  2 . The tray  1  includes a main body  10 , a disc loader  20 , and a plurality of hook-like retainers  30 .  
         [0021]     The main body  10  is substantially rectangular, and has a panel  12  fixed to a front thereof.  
         [0022]     The disc loader  20  includes a first disc receiving region  22 , and a concentric second disc receiving region  23 . The first disc receiving region  22  is depressed from an upper surface (not labeled) of the main body  10 . A circular side wall  21  surrounds the first disc receiving region  22 . The second disc receiving region  23  is concentrically depressed from a bottom (not labeled) of the first disc receiving region  22 . The first and second disc receiving regions  22 ,  23  are respectively for accommodating a 12 cm (centimeter) disc and an 8 cm disc. A slot  26  is defined in the main body  10 , spanning from a center of the disc loader  20  to a back of the tray  1 . The slot  26  includes an arch-shaped portion  28  and a rectangular portion  27 . The arch-shaped portion  28  is used for allowing a spindle motor (not visible in  FIG. 1 ) of the disc drive  2  to extend therethrough. The rectangular portion  27  is used for allowing a pickup head (not visible in  FIG. 1 ) of the disc drive  2  to move therealong and thereby track tracks of the disc.  
         [0023]     The hook-like retainers  30  extend radially inwardly from an upper edge of the side wall  21  of the main body  10 . The hooks  30  are evenly arranged along the entire length of the side wall  21 . An imaginary circle that passes through inner edges of the hooks  30  has a diameter larger than an outer diameter of the disc  3 , so as to allow the disc  3  to be loaded in the disc loader  20  of the tray  1  without interference when the tray  1  is horizontally oriented. When the tray is vertically oriented with the disc  3  being received therein, the disc  3  is supported and retained by the lower hooks  30  due to gravitational force acting on the disc  3 . In order words, an edge portion of the disc  3  is brought into contact with the side wall  21 . The disc  3  is in effect clamped by the hooks  30 , thereby preventing the disc  3  from being displaced from the tray  1 . Advantageously, disc drives employing the tray  1  can be operated horizontally or vertically.  
         [0024]     Referring to  FIG. 2  and  FIG. 3 , the tray  1  is made by a conventional molding process. A plurality of molding holes  32  is defined in the first disc receiving region  22  under the corresponding hooks  30 . In order to reduce noise that could be caused by the molding holes  32 , a plurality of sealing members  31  is attached to the bottom of the first disc receiving region  22 , thereby sealing the molding holes  32 . When the disc  3  received in the disc drive  2  is rotated by the spindle motor at high speed, a first airflow  100   a  over the rotating disc  3  and a second airflow  100   b  under the rotating disc  3  are generated. Because the sealing members  31  block the second airflow  100   b  from flowing through the molding holes  32 , any noise due to the molding holes  32  can be effectively reduced. Similarly, any vibration of the disc  3  can be effectively reduced. In an alternative embodiment, the sealing members  31  may be configured to partially or completely fill the molding holes  32 .  
         [0025]     Referring to  FIG. 4 , this illustrates a tray  1 ′ in accordance with a second preferred embodiment of the present invention. The tray  1 ′ is made by means of a mold having one or more cores. Thus a plurality of recesses  32 ′ is defined in a first disc receiving region  22 ′. The recesses  32 ′ facilitate detaching of the loose cores from the tray  1 ′ during the demolding process. With such configuration, no mold releasing holes are defined in the first disc receiving region  22 ′. When the disc  3  received in the disc drive  2  is rotated by the spindle motor at high speed, a first airflow  200   a  over the rotating disc  3  and a second airflow  200   b  under the rotating disc  3  are generated. Due to the absence of mold releasing holes, any noise and vibration of the disc  3  are significantly reduced.  
         [0026]     Table 1 shows noise levels of three disc drives that respectively employ the tray  1   a  (related art), the tray  1  (first embodiment of present invention), and the tray  1 ′ (second embodiment of present invention).  
                                                                             Tray 1a   Tray 1   Tray 1′                                        Noise level   51.66   49.60   34.66           (dBA)                      
 
         [0027]     As is shown in Table 1, when a disc is rotated at high speed, the noise level in the disc drive employing the tray  1  or the tray  1 ′ is significantly lower than that in the disc drive employing the tray  1   a.  That is, noise can be efficiently reduced by employing the tray  1  or the tray  1 ′.  
         [0028]     It should be emphasized that the above-described embodiments, including any preferred embodiments, are merely possible examples of implementation of the principles of the invention, and are merely set forth for a clear understanding of the principles of the invention. Many variations and modifications may be made to the above-described embodiments without departing substantially from the spirit and principles of the invention. All such modifications and variations are intended to be included herein within the scope of this disclosure and the present invention and be protected by the following claims.