Patent Publication Number: US-2007103860-A1

Title: Latch device for a tablet personal computer

Description:
RELATED APPLICATIONS  
      The present application is based on, and claims priority from, Taiwan Application Serial Number 94139478, filed Nov. 10, 2005, the disclosure of which is hereby incorporated by reference herein in its entirety.  
     BACKGROUND  
      1. Field of Invention  
      The present invention relates to a latch device for a liquid crystal display. More particularly, the present invention relates to a latch device for a liquid crystal display of a tablet personal computer.  
      2. Description of Related Art  
      The technology and manufacturing techniques of notebook computers are becoming better developed with each passing day. The notebook computer has thus become more and more popular. However, because of viewing angle limitations of liquid crystal display of the notebook computer, not all viewers huddled around the notebook computer can clearly view images. The notebook computer display must be repositioned to suit any one particular viewer.  
      Tablet personal computers have been innovated to overcome this limitation. The screen display of the tablet personal computer not only has a humanized input function but also can be flipped over so that viewers around the tablet personal computer can see the information and images on the screen display more easily than before. The flipping design of the tablet personal computer means that latching a front side or a back side of the liquid crystal display onto a base of the tablet personal computer is an important design feature.  
       FIG. 1  is a schematic diagram showing a rotatable hook of a conventional tablet personal computer. The tablet personal computer includes a base  104  and a screen display  102 . A rotatable hook  106  pivotally configured in the screen display  102  is used to fasten the screen display  102  on a base  104 . To open the screen display  102 , a user presses a button  108  to release the rotatable hook  106  from a hollow  109  mounted on the base  104 , thereby separating the rotatable hook  106  from the hollow  109  and releasing the screen display  102 .  
      However, the rotatable hook of the conventional tablet personal computer is not conveniently operated. For example, after the screen display  102  is turned over, a front side of the screen display  102  is displayed upward. To close the screen display  102 , the position of the rotatable hook  106  needs to be changed by hand to fasten the rotatable hook  106  in the hollow  109 . Furthermore, the rotatable hook  106  easily scrapes and damages the hollow  109 , marring the shell appearance of the tablet personal computer.  
     SUMMARY  
      In one aspect, the embodiment of this present invention provides a latch device applied in a tablet personal computer to latch a front side or a back side of a screen display onto a base to enhance operation convenience.  
      In another aspect, the embodiment of this present invention provides a latch device applied in a tablet personal computer whose hook can be repositioned quickly after flipping over the first shell element of the tablet personal computer.  
      In still another aspect, the embodiment of this present invention provides a latch device applied in a tablet personal computer that provides a hook sliding up and down to decrease damage of a hollow and maintain the appearance of the tablet personal computer.  
      In accordance with the foregoing and other aspects of the present invention, the embodiment of the present invention provides a latch device applied in a tablet personal computer. A tablet personal computer comprises a first shell element and a second shell element. The first shell element has a front side and a back side. The second shell element is pivotally coupled with one end of the first shell element, wherein the first shell element can be flipped over relative to the second shell element to make the front side or the back side toward the second shell element. The latch device comprises a first engagement device and a second engagement device.  
      The first engagement device is mounted on the first shell element, wherein the first engagement device comprises a hook, a button and a resilient plate. The hook has a sliding cavity, a first hole and a second hole, wherein the first hole and the second hole are positioned symmetrically in two ends of the hook. The sliding cavity comprises a long axis and a short axis. The resilient plate is mounted against the hook. The button includes a stopper and a bulge that protrudes from the stopper and contacts the resilient plate. The stopper presses on the hook and the bulge is passed through the sliding cavity to slide along the long axis of the sliding cavity up and down. Thus, one end having the first hole of the hook protrudes from the front side of the first shell element, or the other end having the second hole of the hook protrudes from the back side of the first shell element.  
      The second engagement device is mounted on the second shell element, wherein the second engagement device comprises a hollow and a protrusion. The protrusion mounted on the hollow clasps the first hole and the second hole selectively. The protrusion can be a projection according to demands.  
      Thus, the present invention provides a latch device to latch a front side or a back side of a screen display onto a base to enhance operation convenience. Moreover, the hook of the latch device of the present invention can be repositioned quickly after flipping over the first shell element of the tablet personal computer. Furthermore, the latch device of the present invention provides the hook sliding up and down to protrude from the front side and the back side of the first shell element. Besides, the latch device of the present invention can decrease damage of the hollow and maintain the appearance of the tablet personal computer.  
      It is to be understood that both the foregoing general description and the following detailed description are by examples and are intended to provide further explanation of the invention as claimed. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The invention can be more fully understood by reading the following detailed description of the preferred embodiment with reference made to the accompanying drawings as follows:  
       FIG. 1  is a schematic diagram showing a rotatable hook for a conventional tablet personal computer.  
       FIG. 2  is a schematic diagram showing a latch device of a tablet personal computer according to one embodiment of the present invention.  
       FIG. 3  is a perspective diagram showing the partial enlarged first engagement  200  according to  FIG. 2 .  
       FIG. 4  is a cross-sectional schematic diagram along the A-A line in  FIG. 3 , showing an engagement of the hook with the protrusion.  
       FIG. 5  is a cross-sectional schematic diagram along the A-A line in  FIG. 3 , showing the hook separated from the protrusion.  
       FIG. 6  is a schematic diagram showing a tablet personal computer with the screen display flipped over according to one embodiment of the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      The present invention provides a latch device to flip a front side or a back side of a liquid crystal display onto a base to enhance operation convenience. Reference is now made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts.  
       FIG. 2  is a schematic diagram showing a latch device of a tablet personal computer according to one embodiment of the present invention. In  FIG. 2 , a tablet personal computer comprises a first shell element  110  and a second shell element  112 . The first shell element  110  includes a screen display  118  (shown in  FIG. 6 ) and a first engagement device  200 . The second shell element  112  comprises a keyboard  114 , a touch panel  116  and a second engagement device  210 . The first shell element  110  is fastened on the second shell element  112  by clasping the first engagement device  200  with the second engagement device  210 .  
       FIG. 3  is a perspective diagram showing the partial enlarged first engagement  200  according to  FIG. 2 , but omitting a button  203 . A hook  202  is configured in the first shell element  110 . The hook  202  has a sliding cavity  203 , a first hole  202   a  and a second hole  202   b  that are positioned symmetrically in two ends of the hook  202 . The sliding cavity  203  has a long axis h 1  and a short axis h 2 . The hook  202  is slid up and down along the long axis h 1  of the sliding cavity  203  to protrude from a front side or a back side of the first shell element  110 . In  FIG. 2  and  FIG. 3 , the hook  202  is protruded from the back side of the first element  110 .  
       FIG. 4  is a cross-sectional schematic diagram along the A-A line in  FIG. 3 , showing an engagement of the hook with the protrusion. The first engagement device  200  configured in the first shell element  110  comprises a button  204 , a hook  202  and a resilient plate  206 . The button  204  has a stopper  204   a  and a bulge  204   b  protruded from the stopper  204   a . The width of the stopper  204   a  is larger than the short axis h 2  of the sliding cavity  203  to touch on the sidewall thereof. The bulge  204   b  protrudes through the sliding cavity  203  and contacts the resilient plate  206 . The resilient plate  206  is located against the hook  202 .  
      The second engagement device  210  configured in the second shell element  112  comprises a hollow  212  and a protrusion  214 . The protrusion  214  is mounted in the hollow  212  to clasp the first hole  202   a  and the second hole  204   b  of the hook  202  selectively.  
       FIG. 5  is a cross-sectional schematic diagram along the A-A line in  FIG. 3 , showing the hook separated from the protrusion. When the button  204  is pressed by finger  216 , the stopper  204   a  of the button  204  pushes the hook  202  and the resilient plate  206  inside the first shell element  110  to move the hook  202  backward and deform the resilient plate  206 . Then, the first shell element  110  is pulled up to separate the hook  202  from the hollow  212 . Thus, the first shell element  110  is separated from the second shell element  112 , as shown in  FIG. 2 .  
      To close the first shell element  110  against the second shell element  112 , one end having the second hole  202   b  of the hook  202  is inserted into the hollow  212 . Then, the button  204  is pressed by the finger  216  to push the stopper  204   a  of the button  204  carrying the hook  202  and the resilient plate  206  inside the first shell element  110  to move the hook  202  backward and deform the resilient plate  206 . The hook  202  falls by gravity to align with the second hole  202   b  at the protrusion  214 , as shown in  FIG. 5 . After releasing the button  204 , the restoring force of the resilient plate  206  produced by compressing the resilient plate  206  pushes the hook  202  outside the first shell element  110  to clasp the hook  202  and the protrusion  214 , as shown in  FIG. 4 . The first shell element  110  and the second shell element  112  are thus closed.  
      Alternatively, the first hole  202   a  of the hook  202  can be clasped with the protrusion of the second engagement device  210  according to the demands.  FIG. 6  is a schematic diagram showing a tablet personal computer with the screen display flipped over according to one embodiment of the present invention. In  FIG. 6 , the screen display  118  is upward after flipping over the first shell element  110 . The first hole  202   a  of the hook  202  is clasped with the protrusion  214  of the second shell element  112 . Thus, the hook  202  can be slid up and down according to the demands. The hook  202  can be protruded from the front side and the back side of the first shell element  110  selectively. The first hole  202   a  of the hook  202  can be clasped with the second engagement device  210  while the screen display  118  is upward. The second hole  202   b  can be clasped with the second engagement device  210  while the screen display  118  is downward.  
      Thus, the present invention provides a latch device to latch a front side or a back side of a screen display onto a base to enhance operation convenience. Moreover, the hook of the latch device of the present invention can be repositioned quickly after flipping over the first shell element of the tablet personal computer. Furthermore, the latch device of the present invention provides the hook sliding up and down to protrude from the front side and the back side of the first shell element. Besides, the latch device of the present invention can decrease damage of the hollow and maintain the appearance of the tablet personal computer.  
      It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention cover modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents.