You are an expert at summarizing long articles. Proceed to summarize the following text:

You are an expert at summarizing long articles. Proceed to summarize the following text: 
FIELD OF THE INVENTION  
       [0001]     The present invention relates to locks and more particularly to a magnetic lock having a particular application in electronic device.  
       BACKGROUND OF THE INVENTION  
       [0002]     A variety of electronic and information products are developed due to the fast progress in electronics and computer technology. Correspondingly, more and more users become more critical with respect to the functions and the quality of the products. The increasing consumer demand with respect to manufacturers of portable computer, particularly notebook computer, is very significant.  
         [0003]     The trend of developing notebook computers is slimness, compactness, and lightweight in consideration of weight and size. Moreover, an all-in-one notebook computer is constantly being sought. Nowadays, all-in-one notebook computers are dominant type of portable computers. It is understood that the notebook computer market is very competitive. Fortunately, a wide variety of notebook computers are available for consumers to choose. It also understood that most consumers want to buy an all-in-one, ergonomic notebook computer in a cost effective price. It is concluded that if a notebook computer manufacturer wants to win over other competitive manufacturers how to provide user with ergonomic notebook computers in a reasonable price should be a deciding factor.  
         [0004]     A notebook computer, as self-explanatory, means the computer can be easily opened or closed just like opening or closing a notebook. As shown in  FIG. 1 , a prior parallelepiped notebook computer comprises a display  10  and a case  11 . At least one hinge  12 , provided at one side of the case  11 , is coupled to the display  10 . As such, in a nonoperating position the display  10  is covered the case  11 . For using the notebook computer, a user can pivot the display  10  about the hinge  12  upward to position the display  10  at an optimum angle about the case  11  for viewing. A keyboard  13  and a touch panel  14  are provided on top of the case  11  proximate the display  10 . Also, two spaced slots  15  are formed at a top edge of the case  11  distal from the display  10 . A slide lock  16  is provided on one side of the display  10  distal from the hinge  12 . The lock  16  is adapted to prevent the notebook computer from opening. For locking the notebook computer, slide the lock  16  to cause two hooks  161  at both sides of the lock  16  to move laterally. The lateral movements of the hooks  161  will cause the hooks  161  to insert into the slots  15  for fastening the display  10  and the case  11  together (i.e., locked) in response to closing the display  10  onto the case  11 .  
         [0005]     However, a precise manufacturing of a connecting mechanism of the slide lock  16  and the hooks  161  is required since newly developed notebook computers are more lightweight and more compact. As a result, a user may have difficulty in feeling whether the hooks  161  are disengaged from the slots  15  in opening the display  10  since the lateral movement of the lock  16  is relatively small. It is typical that a user uses one hand to push the lock  16  and the other hand to open the display  10 . However, the user has to exert a great force to open the display  10  due to the own weight of the display  10 . Hence, it is not easy to open the display  10 . It is often that a user may use a great force to open the display  10  not being aware that the hooks  161  are not disengaged from the slots  15 . As a result, the lock  16 , the hooks  161 , and other associated members are susceptible of damage. Further, a great inconvenience and trouble may be brought to users.  
         [0006]     Moreover, the protruding hooks  161  are not aesthetic in addition to the above drawback of being susceptible of damage. It is concluded that the prior lock is not a perfect design.  
         [0007]     Thus, it is desirable among vast users and manufacturers to provide a notebook computer having a novel lock capable of easily, conveniently opening the display  10  from the case  11  or closing the display  10  onto the case  11 .  
       SUMMARY OF THE INVENTION  
       [0008]     A primary object of the present invention is to provide a magnetic lock mountable on an electronic device capable of opening or closing. The magnetic lock comprises an upper magnetic plate formed on an upper housing of the electronic device and a lower magnetic plate formed on a lower housing of the electronic device. The electronic device is automatically locked because magnetic members of the upper magnetic plate attract magnetic members of the lower magnetic plate having a polarity different from that of the magnetic members of the upper magnetic plate when the upper housing is covered the lower housing. Alternatively, a user can move the upper magnetic plate about the lower magnetic plate a predetermined distance to repel the magnetic members of the upper magnetic plate from the magnetic members of the lower magnetic plate having the same polarity as that of the magnetic members of the upper magnetic plate to unlock the electronic device. By utilizing the present invention, the above drawbacks of the prior art can be overcome. These drawbacks are that the protruding hooks are not aesthetic, it is not easy to open the display for unlocking the notebook computer, and it is often that a user may use a great force to open the display not being aware that the hooks are not disengaged from the slots, resulting in a great possibility of easily damaging the slide lock, the hooks, and other associated. The magnetic lock of the present invention also has the following advantages. It can be realized in a simple construction, simple manufacturing, and low cost. Further, the magnetic lock of the present invention is compact, simple and easy in operation, and ergonomic.  
         [0009]     The above and other objects, features and advantages of the present invention will become apparent from the following detailed description taken with the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]      FIG. 1  is a perspective view of a notebook computer incorporating conventional slide lock and associated hooks;  
         [0011]      FIG. 2  is a diagram schematically illustrating a magnetic lock according to a first preferred embodiment of the invention;  
         [0012]      FIG. 3  is a perspective view of a notebook computer incorporating the magnetic lock;  
         [0013]      FIG. 4  is a diagram schematically illustrating attracting force between an upper magnetic plate and a lower magnetic plate of the magnetic lock;  
         [0014]      FIG. 5  is a diagram schematically illustrating repelling force between an upper magnetic plate and a lower magnetic plate of the magnetic lock; and  
         [0015]      FIG. 6  is a perspective view of a notebook computer incorporating a magnetic lock according to a second preferred embodiment of the invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0016]     Referring to  FIG. 2 , there is shown a magnetic lock  2  in accordance with a first preferred embodiment of the invention. The magnetic lock is adapted to mount on an electronic device (e.g., notebook computer, palm computer, or the like) capable of opening or closing. The magnetic lock  2  comprises an elongate, rectangular upper magnetic plate  20  and an elongate, rectangular lower magnetic plate  30 . The upper magnetic plate  20  comprises a plurality of alternate magnetic members  21  of positive polarity (+) and magnetic members  21  of negative polarity (−) from one end to the other end. Each of the magnetic members  21  of positive polarity (+) and the magnetic members  21  of negative polarity (−) is formed of a magnetic pad  21  in this embodiment. As shown in  FIG. 2 , similar to the upper magnetic plate  20 , the lower magnetic plate  30  comprises a plurality of alternate magnetic members  31  of positive polarity (+) and magnetic members  31  of negative polarity (−) from one end to the other end. Each of the magnetic members  31  of positive polarity (+) and the magnetic members  31  of negative polarity (−) is formed of a magnetic pad  31  in the embodiment. It is appreciated by those skilled in the art that the magnetic pads  21  and  31  may be replaced by members formed of similar materials in other embodiments without departing from the scope and spirit of the invention.  
         [0017]     As stated above, the magnetic lock  2  is adapted to mount on an electronic device capable of opening or closing. Thus, following description will be made with respect to the magnetic lock  2  mounted on a notebook computer  40 . Referring to  FIG. 3 , the notebook computer  40  is substantially the same as a typical one. The parallelepiped notebook computer  40  comprises a display  41  and a case  42 . At least one hinge  43 , provided at one side of the case  42 , is coupled to the display  41 . As such, the display  41  is able to pivot about the hinge  43  to open or close the notebook computer  40 . A keyboard  44  and a touch panel  45  are provided on top of the case  42 . A slide lock  46  is provided on one side of the display  41  distal from the hinge  43 . The upper magnetic plate  20  is able to engage with the lower magnetic plate  30  when the display  41  is covered the case  42  by pivoting (see  FIG. 2 ). The upper magnetic plate  20  is adjacent the slide lock  46  on the display  41  (see  FIG. 3 ). As shown in  FIG. 4 , the other end of the upper magnetic plate  20  is coupled to one end of an elastic element (e.g., spring)  47  which has the other end anchored at an interior wall  411  of the display  41 .  
         [0018]     By configuring the magnetic lock  2  as above, referring to  FIGS. 3 and 4  again, the display  41  is covered the case  42  by pivoting. It is clearly seen that the magnetic pads  21  will attract the magnetic pads  31  if they are different in polarity (i.e., the magnetic pads  21  of positive polarity (+) attract the magnetic pads  31  of negative polarity (−) and the magnetic pads  21  of negative polarity (−) attract the magnetic pads  31  of positive polarity (+) respectively) due to magnetism. As a result, the notebook computer  40  is locked because the display  41  and the case  42  are fastened together.  
         [0019]     Referring to  FIGS. 3 and 5 , to the contrary, in a case of opening the notebook computer  40  by pushing the lock  46  toward the elastic element  47  for compression, the upper magnetic plate  20  moves laterally a distance. The magnetic pads  21  will also move. As such, the magnetic pads  21  of one polarity are aligned with the magnetic pads  31  of the same polarity (i.e., the magnetic pads  21  of positive polarity (+) are aligned with the magnetic pads  31  of positive polarity (+) and the magnetic pads  21  of negative polarity (−) are aligned with the magnetic pads  31  of negative polarity (−) respectively) if the moving distance of the upper magnetic plate  20  is sufficient. In this position, the upper magnetic plate  20  will repel the lower magnetic plate  30  (i.e., the magnetic pads  21  of positive polarity (+) repel the magnetic pads  31  of positive polarity (+) and the magnetic pads  21  of negative polarity (−) repel the magnetic pads  31  of negative polarity (−) respectively) due to magnetism. As a result, the repelling force between the display  41  and the case  42  will form a gap therebetween. As such, a user can quickly pivot the display  41  upward by inserting finger(s) into the gap. Moreover, the upper magnetic plate  20  will be pushed back to its original position immediately thereafter by the expansion of the elastic element  47  coupled to the other end of the upper magnetic plate  20  once the pushing force exerted on the lock  46  is released. This is done due to the elasticity of the elastic element  47 . Thus, the upper magnetic plate  20  and the lower magnetic plate  30  will attract again for locking the notebook computer  40  if they are engaged again when the display  41  is covered the case  42  (see  FIG. 4 ).  
         [0020]     The magnetic lock  2  of the invention is made possible by utilizing magnetism. That is, two magnetic members having different polarities will attract each other and to the contrary, two members having the same polarity will repel each other. As such, a device can be locked or unlocked by incorporating the above magnetic members. Further, the magnetic lock  2  can be implemented is one of a variety of forms. Referring to  FIG. 6 , the upper magnetic plate  20  is implemented as a disc comprising a top ridge  22  across its center so as to form a magnetic pad  21  of positive polarity (+) at one half and a magnetic pad  21  of negative polarity (−) at the other half. The upper magnetic plate  20  further comprises a tab  23  extended downward from its bottom. Also, the upper magnetic plate  20  is rotatable about the tab  23 . The lower magnetic plate  30  is disposed corresponding to the upper magnetic plate  20  and is implemented as a circular one. The lower magnetic plate  30  comprises a hole  32  through its center, the hole  32  being conformed to receive the tab  23 , a magnetic pad  31  of negative polarity (−) at one half, and a magnetic pad  31  of positive polarity (+) at the other half. In a case of closing a device, the tab  23  will insert into the hole  32  as an upper case  60  of the device is engaged with a lower case  61  of the device by pivoting. At this position, the upper magnetic plate  20  formed on the upper case  60  and the lower magnetic plate  30  formed on the lower case  61  are coupled together in which the magnetic pad  21  of positive polarity (+) attracts the magnetic pad  31  of negative polarity (−) and the magnetic pad  21  of negative polarity (−) attracts the magnetic pad  31  of positive polarity (+) respectively due to magnetism. As a result, the device is locked because the upper case  60  and the lower case  61  are fastened together.  
         [0021]     To the contrary, for opening the device it is possible of rotating the upper magnetic plate  20  180 degrees about the tab  23  which, as stated above, is fastened in the hole  32 . Once the magnetic pad  21  of one polarity is aligned with the magnetic pad  31  of the same polarity by the above rotation (i.e., the magnetic pad  21  of positive polarity (+) is aligned with the magnetic pad  31  of positive polarity (+) and the magnetic pad  21  of negative polarity (−) is aligned with the magnetic pad  31  of negative polarity (−) respectively) the upper case  60  will repel the lower case  61  (i.e., the magnetic pad  21  of positive polarity (+) repels the magnetic pad  31  of positive polarity (+) and the magnetic pad  21  of negative polarity (−) repels the magnetic pad  31  of negative polarity (−) respectively) due to magnetism. As a result, the repelling force between the upper case  60  and the lower case  61  will form a gap therebetween. As such, a user can quickly pivot the upper case  60  upward for opening the device by inserting finger(s) into the gap.  
         [0022]     It will be evident from the foregoing that the magnetic lock  2  of the invention has the following advantages: It can be realized in a simple construction, simple manufacturing, and low cost. Further, the magnetic lock  2  of the invention is compact, simple and easy in operation, and ergonomic.  
         [0023]     While the invention has been described by means of specific embodiments, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope and spirit of the invention set forth in the claims.

Summary:
The present invention is to provide a magnetic lock mountable on an electronic device, which comprises an upper and a lower magnetic plates respectively formed on an upper and a lower housings of the electronic device, enabling the electronic device to be automatically locked due to the attraction between a plurality of magnetic members disposed on the corresponding positions of the upper and lower magnetic plates having different polarities when the upper housing is covered the lower housing. Alternatively, when the upper magnetic plate is moved a predetermined distance, the corresponding magnetic members on the upper and lower magnetic plates are in turn having the same polarity to repel with each other, enabling the upper and lower housings of the electronic device to be automatically unlocked.