Abstract:
An optical/mechanical applied to a disc drive includes a spindle motor, a base plate, a principal guiding bar, and an optical pickup head. The spindle motor and the principal guiding bar are disposed on the base plate. The optical pickup head is movably disposed on the principal guiding bar and shifts along the axial direction of the principal guiding bar.

Description:
[0001]     This application claims the benefit of Taiwan application Serial No. 93119170, filed Jun. 29, 2004, the subject matter of which is incorporated herein by reference.  
       BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The invention relates in general to an optical disc drive, and more particularly to a mecha of the optical disc drive.  
         [0004]     2. Description of the Related Art  
         [0005]     The hardware structure of an optical disc drive mainly comprises a mecha and an electric control module. The main function of the mecha is to rotate an optical disc and generate light spots to access data from the optical disc. The constituting element of the mecha comprises a spindle motor for driving an optical disc to rotate, and an optical pickup head for generating light spots to access data from the optical disc.  
         [0006]     Referring to both  FIG. 1  and  FIG. 2 , wherein  FIG. 1  is a decomposition diagram of a conventional mecha in an optical disc drive, while  FIG. 2  is an assembly diagram of a mecha in  FIG. 1 . Conventional mecha  100  in an optical disc drive mainly comprises a mounting plate  102 , a spindle motor base-plate  104 , a spindle motor  106 , a principal guiding bar  108  and an optical pickup head  110 .  
         [0007]     The first principal guiding bar base unit  112   a  and the second principal guiding bar base unit  112   b  are respectively locked onto the two sides of the mounting plate  102  via the first locking screw  114   a  and the second locking screw  114   b . The principal guiding bar  108  is disposed on the mounting plate  102  by using the first principal guiding bar base unit  112   a  and the second principal guiding bar base unit  112   b  to respectively receive and fix the first bar end  116   a  and the second bar end  116   b  of the principal guiding bar  108 .  
         [0008]     The optical pickup head  110  is moveably disposed on the principal guiding bar  108  and shifts along the axial direction of the principal guiding bar  108 . For example, the axle sleeve  118 , which is fixed onto the optical pickup head  110 , receives the principal guiding bar  108 , so that the optical pickup head  110  shifts along the axial direction of the principal guiding bar  108  via the axle sleeve  118 . Besides, the mounting plate  102  has a secondary guiding bar  120  disposed thereon, wherein the secondary guiding bar  120  is for supporting the optical pickup head  110  in movement, so that the optical pickup head  110  keeps stable when accessing data from the rotating optical disc driven by the spindle motor  106 .  
         [0009]     On the other hand, the spindle motor base-plate  104  is locked onto the mounting plate  102  via the first locking element set  122   a  and the second locking element set  122   b , and the spindle motor  106  is disposed on the spindle motor base-plate  104 .  
         [0010]     Generally speaking, how good the mecha of an optical disc drive recognizes an optical disc is an important index showing the quality of an optical disc drive. As shown in  FIG. 2 , Y 1 , the distance from the rotation center of the spindle motor  106  to the axis of the principal guiding bar  108 , is exactly a key factor affecting the capability of accessing an optical disc by the mecha  100 , and more particularly, a key factor with regards to the ability of recognizing an offset optical disc.  
         [0011]     In the above conventional mecha  100 , assembly tolerance respectively exists between the spindle motor base-plate  104  and the mounting plate  102 , and between the spindle motor  106  and the spindle motor base-plate  104 . Besides, assembly tolerance also exist between the mounting plate  102  and the first principal guiding bar base unit  112   a  as well as the second principal guiding bar base unit  112   b , and between the principal guiding bar  108  and the first principal guiding bar base unit  112   a  as well as the second principal guiding bar base unit  112   b . Moreover, the above elements have their own manufacturing tolerance as well.  
         [0012]     Therefore, Y 1 , the distance from the rotation center of the spindle motor  106  to the axis of the principal guiding bar  108 , would accumulate considerable amount of tolerance, and deviate from the design value considerably, causing the mecha  100  to fail to access the optical disc and hindering the improvement of the quality of the optical disc drive.  
       SUMMARY OF THE INVENTION  
       [0013]     It is therefore an object of the invention to provide an mecha of an optical disc drive, whose distance from the rotation center of the spindle motor to the axis of the principal guiding bar better complies with the designed value, enhancing the mecha to have a better ability of accessing optical disc, hence improving the quality and efficiency of the optical disc drive.  
         [0014]     According to the above object, the invention provides a mecha of a disc drive, comprising a spindle motor, a base plate, a principal guiding bar, and an optical pickup head. The spindle motor and the principal guiding bar are disposed on the base plate. The optical pickup head is movably disposed on the principal guiding bar and shifts along the axial direction of the principal guiding bar. The mecha of the invention further comprises a mounting plate on which the spindle motor base-plate is disposed.  
         [0015]     Moreover, in the mecha of the invention, the principal guiding bar has a first bar end and a second bar end, while the spindle motor base-plate can comprise a first supporting portion and a second supporting portion. The first supporting portion and the second supporting portion are respectively opposite to the first bar end and the second bar end. The first supporting portion has a first indention, while the second supporting portion has a second indention. The first indention and the second indention respectively receive and fix a first bar end and a second bar end, so that the principal guiding bar are disposed on the spindle motor base-plate.  
         [0016]     In the mecha of the invention, the first supporting portion and the second supporting portion respectively can be a first protrusion pair and a second protrusion pair, or a first bearer and a second bearer. The pair of first protrusions and the pair of second protrusions can respectively be formed in one block on the spindle motor base-plate. Besides, the first bearer and the second bearer respectively can have a formed-in-one-block structure, or respectively ca be formed on the spindle motor base-plate through ejection.  
         [0017]     Other objects, features, and advantages of 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. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0018]      FIG. 1  is a decomposition diagram of a conventional mecha in an optical disc drive;  
         [0019]      FIG. 2  is an assembly diagram of an mecha in  FIG. 1 ;  
         [0020]      FIG. 3  is a schematic diagram of an mecha of an optical disc drive according to a preferred embodiment of the invention;  
         [0021]      FIG. 4A  is a decomposition diagram of a spindle motor and a principal guiding bar of an mecha in  FIG. 3 ;  
         [0022]      FIG. 4B  is an assembly diagram of  FIG. 4A ; and  
         [0023]      FIG. 5  is another schematic diagram of a bearer disposed on a spindle motor base-plate for fixing the principal guiding bar. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0024]     Despite the invention is exemplified by a preferred embodiment, the scope of protection of the invention is not limited thereto. The embodiment is a mecha of an optical disc drive according to the spirit of the invention. The characteristics of technology of the invention are disclosed herein.  
         [0025]     Referring to  FIG. 3 ,  FIG. 4A  and  FIG. 4B .  FIG. 3 a  schematic diagram of a mecha of an optical disc drive according to a preferred embodiment of the invention.  FIG. 4A  is a decomposition diagram of a spindle motor and a principal guiding bar of a mecha in  FIG. 3 .  FIG. 4B  is an assembly diagram of  FIG. 4A . Mecha  300  of the optical disc drive of the invention mainly comprises a mounting plate  302 , a spindle motor base-plate  304 , a spindle motor  306 , a principal guiding bar  308  and an optical pickup head  310 .  
         [0026]     Referring to both  FIG. 4A  and  FIG. 4B . The spindle motor  306  is disposed on the spindle motor base-plate  304 . The spindle motor base-plate  304  is coupled to the spindle motor  306  and has an extension portion  324 . The spindle motor base-plate  304  comprises a first supporting portion and a second supporting portion, which can be a pair of first protrusions  312   a  and a pair of second protrusions  312   b  for instance. The paired first protrusions  312   a  and the paired second protrusions  312   b  are respectively disposed on the two sides of the extension portion  324  of the spindle motor base-plate  304 . The paired first protrusions  312   a  have a first indention  326   a , while the paired second protrusions  312   b  have a second indention  326   b.    
         [0027]     The principal guiding bar  308  has a first bar end  316   a  and a second bar end  316   b  The paired first protrusions  312   a  and the paired second protrusions  312   b  disclosed above are respectively opposite to the first bar end  316   a  and the second bar end  316   b . The first indention  326   a  and the second indention  326   b  respectively receive and fix the first bar end  316   a  and the second bar end  316   b , so that the principal guiding bar  308  is disposed on the extension portion  324  of the spindle motor base-plate  304 .  
         [0028]     Moreover, the optical pickup head  310  is moveably disposed on the principal guiding bar  308  and shifts along the axial direction of the principal guiding bar  308 . For example, an axle sleeve  318  is fixed onto the optical pickup head  310 . Through receiving the principal guiding bar  308  by the axle sleeve  318 , the optical pickup head  310  shifts along the axial direction of the principal guiding bar  308  via the axle sleeve  318 .  
         [0029]     Besides, refer to  FIG. 3  at the same time. The mounting plate  302  has a secondary guiding bar  320  disposed thereon for supporting the optical pickup head  310  in movement, so that the optical pickup head  310  keeps stable when accessing data from the rotating optical disc driven by the spindle motor  306 . Lastly, the spindle motor base-plate  304  having a principal guiding bar  308  and a spindle motor  306  disposed thereon is disposed on the mounting plate  302  and becomes the mecha  300  as shown in  FIG. 3 . Moreover, the mecha  300  can be incorporated together with the body of the optical disc drive via the mounting plate  302  to form an optical disc drive. That is to say, the mounting plate  302  is disposed on the body of an optical disc drive to form an optical disc drive.  
         [0030]     Referring to  FIG. 5 , another schematic diagram of a bearer disposed on a spindle motor base-plate for fixing the principal guiding bar is shown. The diagram illustrates an extension portion  524  of a spindle motor base-plate  504 . Apart from the paired first protrusions  312   a  and the paired second protrusions  312   b  disclosed in above embodiment, the element disposed on the spindle motor base-plate for fixing the elements of the principal guiding bar can be implemented according to the method disclosed below.  
         [0031]     The spindle motor base-plate  504  comprises a first supporting portion and a second supporting portion, which can be a first bearer  512   a  and a second bearer  512   b  for instance. The first bearer  512   a  and the second bearer  512   b  are respectively disposed on the two sides of the extension portion  524  of the spindle motor base-plate  504 . The first bearer  512   a  has a first indention  526   a , while the second bearer  512   b  has a second indention  526   b.    
         [0032]     The first bearer  512   a  and the second bearer  512   b  are respectively opposite to the first bar end  316   a  and the second bar end  316   b  of the principal guiding bar  308  in  FIG. 4A . The first indention  526   a  and the second indention  526   b  respectively receive and fix the first bar end  316   a  and the second bar end  316   b  in  FIG. 4A , so that the principal guiding bar  308  is disposed on the extension portion  524  of the spindle motor base-plate  504 .  
         [0033]     Moreover, in  FIG. 4A , the paired first protrusions  312   a  and the paired second protrusions  312   b  are respectively formed in one block on the extension portion  324  of the spindle motor base-plate  304 . In  FIG. 5 , the first bearer  512   a  and the second bearer  512   b  respectively have a formed-in-one-block structure. Besides, the first bearer  512   a  and the second bearer  512   b  can be respectively formed on the extension portion  524  of the spindle motor base-plate  504  through ejection.  
         [0034]     It can be understood from the above embodiment that both the principal guiding bar  308  and the spindle motor  306  are disposed on the spindle motor base-plate  304  in the mecha  300  of the optical disc drive of the invention, while the principal guiding bar  108  and the spindle motor  106  are respectively disposed on the mounting plate  102  and the spindle motor base-plate  104  in the conventional mecha  100 .  
         [0035]     Therefore, Y 2 , the distance from the rotation center of the spindle motor  306  to the axis of the principal guiding bar  308 , would only accumulate the assembly tolerance between the spindle motor  306  and the spindle motor base-plate  304 , the assembly tolerance between the spindle motor base-plate  304  and the paired first protrusions  312   a  as well as the paired second protrusions  312   b  (or the assembly tolerance between the spindle motor base-plate  504  and the first bearer  512   a  as well as the second bearer  512   b ), and the assembly tolerance between the principal guiding bar  308  and the paired first protrusions  312   a  as well as the paired second protrusions  312   b  (or between the principal guiding bar  308  and the first bearer  512   a  as well as the second bearer  512   b ). Moreover, the manufacturing tolerance of above elements accumulates, while the assembly tolerance between the spindle motor base-plate  304  and the mounting plate  302  and the manufacturing tolerance of the mounting plate  302  are eliminated.  
         [0036]     Given that the paired first protrusions  312   a  and the paired second protrusions  312   b  are respectively formed in one block on the extension portion  324  of the spindle motor base-plate  304 , or that the first bearer  512   a  and the second bearer  512   b  are respectively formed on the extension portion  524  of the spindle motor base-plate  504  through ejection, the assembly precision is higher, largely reducing the assembly tolerance between the spindle motor base-plate  304  and the paired first protrusions  312   a  as well as the paired second protrusions  312   b  or between the spindle motor base-plate  304  and the paired first bearers  512   a  as well as the second bearer  512   b.    
         [0037]     For the mecha  300  of the optical disc drive of the invention, Y 2 , the distance from the rotation center of the spindle motor  306  to the axis of the principal guiding bar  308 , would accumulate less tolerance and is less deviated from the design value, enhancing the capability of accessing optical disc by the mecha  300 , hence improving the quality and efficiency of the optical disc drive.  
         [0038]     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.