Patent Publication Number: US-2006002062-A1

Title: Latch device for portable computer

Description:
BACKGROUND OF THE INVENTION  
      1. Field of Invention  
      The present invention relates to a portable computer, and more particularly, to a latch device which causes a main body and a display to engage each other when the display is folded onto the main body.  
      2. Description of the Prior Art  
       FIG. 1  is a perspective view of a conventional portable computer. Referring to the figure, the portable computer comprises a main body  1  of a substantially flat rectangular shape and a display  3  which pivots about a hinge  5  at a rear end of the main body  1 .  
      The display  3 , which is formed in a plate shape corresponding to the main body  1 , is folded and seated onto an upper face of the main body  1  when safekeeping or carrying the portable computer. The display  3  is unfolded with respect to the main body  1  at a predetermined angle for use, as shown in  FIG. 1 .  
      An inside of the main body  1  is provided with a mainboard and the like of the portable computer, and the upper face of the main body  1  is provided with a keyboard  7 . The keyboard  7  is a portion through which desired informations are inputted as a user presses keys. The display  3  is provided with a liquid crystal panel  9  which displays various informations.  
      When the display  3  and the main body  1  are folded on each other to be safekept or carried, in order to engage the display  3  and the main body  1  to each other, there are provided latch devices  10 . The latch devices  10  are provided at corresponding portions of front ends of a rear case  11  and a front case  12  which form an appearance of the display  3 . The number of the latch devices  10  may be properly determined according to a width of the display  3 .  
      Herein, the rear case  11  forms a rear face of the display  3 , while the front case  12  forms a frame of a front edge of the display  3 . The front case  12 , which is formed in a rectangular frame shape, functions to seal and support an edge of the liquid crystal panel  9  of the display  3 .  
      A space formed between the rear case  11  and the front case  12  is provided with latches and the like forming the latch devices  10 . That is, the latches (not shown) are provided in the space between the rear case  11  and the front case  12  so that hooks  14  are projected in a front end of the front case  12  toward a front face. The hooks  14  are selectively hooked into catching grooves  1 ′ formed at a front end of the upper face of the main body  1 . An operating knob  13  for operating the hook  14  is exposed to a portion corresponding to a side face of the front end of the display  3 .  
      However, the above prior art has the following problems.  
      That is, the latch devices  10  are generally provided at two separate positions. Since the latch devices  10  are separately positioned, when the user unfolds the display  3  with respect to the main body  1 , the operating knobs  13  provided at the respective latch devices  10  should be operated by both hands. Thus, when the display  3  is unfolded with respect to the main body  1 , it is difficult to fix the main body  1 . Generally, it is inconvenient that while the operating knobs  13  are operated by both thumbs the main body  1  should be fixed by some of the other fingers.  
      In order to solve the problem, there is provided a latch device constructed so that a latch device having two hooks is operated by a single operating knob. However, since a length of the latch is relatively elongated as the display  3  becomes large, the latch is easily bent. Thus, there are problems in that the hooks do not correctly hooked into the catching grooves, and then, a gap occurs between the main body  1  and the display  3 .  
      Further, if the latch is relatively elongated, since the latch occupies a large inner space of the display  3 , practical usability of the inner space of the display  3  is relatively reduced.  
     SUMMARY OF THE INVENTION  
      Accordingly, the present invention is conceived to solve the aforementioned problems in the prior art. An object of the present invention is to provide a latch device which securely engages a main body and a display to each other and easily operates in case of a portable computer with relatively large dimensions.  
      Another object of the present invention is to provide a latch device which makes it possible to minimize a space necessary to install a latch including a plurality of hooks operated by an operating knob.  
      A further object of the present invention is to provide a latch device which makes it possible to minimize the number of parts of the latch.  
      According to an aspect of the present invention for achieving the objects, there is provided a latch device of a portable computer having a display operating to be folded onto or unfolded with respect to a main body about a hinge, comprising a latch that includes a latch body with a predetermined length, hooks projected from a front end of the display at both ends of the latch body and selectively hooked into a side of the main body, and a moving guide with a guide slot formed therein, and is installed to be translated in the display; an operating knob that has one side thereof detachably engaged with the latch body and is installed such that a knob portion thereof is exposed to an outside of the display; and a restoring member providing a force for moving the latch body in a direction in which the hooks are engaged with the main body.  
      The latch body may be provided with at least two moving guides.  
      Preferably, a fastening boss for engaging a rear case and a front case which form an appearance of the display is seated in the guide slot of the moving guide, thereby guiding the movement of the latch and defining an installation position thereof.  
      More preferably, the latch is installed in a rear case forming an appearance of the display, and an inner face of the rear case is provided with at least two guide hooks for guiding a side of the latch body in order to guide the movement of the latch and at least two guide pieces for guiding an opposite side of the latch body which is guided by the guide hooks.  
      Still more preferably, a front end of each of the guide hooks is formed with a catching projection to prevent the latch body from moving in a direction in which the latch body is separated from the inner face of the rear case, and steps of the latch body in which the catching projections are seated are formed to be relatively lower than the other portions of the latch body.  
      Still more preferably, a guide stopper is formed, at an end side of the latch body to which is connected to the restoring member, in the rear case so as to guide a surface of the latch body and a surface thereof perpendicular thereto, thereby guiding the movement of the latch body and defining an installation position thereof.  
      The operating knob may comprise a knob body provided with a catching hook for engaging with the latch body; the knob portion provided at a side of the knob body and exposed to the outside of the display; and an assembly guide pin for guiding an insertion direction of the knob body.  
      Preferably, a rear case forming an appearance of the display is formed with a plurality of supporting knobs on which the latch body is seated, and the supporting knobs are formed such that the latch body is positioned at a constant level as a whole regardless of the shape of the rear case.  
      According to the present invention constructed as above, since the hooks of the latch for engaging the display and the main body in a portable computer with relatively large dimensions may be installed at both ends of the display, the latch makes the engagement between the display and the main body secure, and a space necessary to install the latch in the display can also be minimized. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The above and other objects, features and advantages of the present invention will become apparent from the following description of preferred embodiments given in conjunction with the accompanying drawings, in which:  
       FIG. 1  is a perspective view showing a conventional portable computer;  
       FIG. 2  is an exploded perspective view showing a major portion of a first embodiment of a portable computer to which a latch device according to the present invention is applied;  
       FIG. 3   a  is a front view showing a latch according to a first embodiment of the present invention;  
       FIG. 3   b  is a side view showing the latch according to the first embodiment of to the present invention;  
       FIG. 3   c  is a sectional view showing an inside of the latch according to the first embodiment of the present invention;  
       FIG. 4  is a sectional view showing the major portion of the first embodiment of the present invention;  
       FIGS. 5   a  to  5   c  are views showing processes of assembly and operation of the first embodiment of the present invention;  
       FIG. 6  is an exploded perspective view showing a major portion of a portable computer to which a latch device according to a second embodiment of the present invention is applied;  
       FIG. 7  is a plan view showing the major portion of the second embodiment according to the present invention;  
       FIG. 8   a  is a front view showing a latch according to the second embodiment of the present invention;  
       FIG. 8   b  is a plan view showing the latch according to the second embodiment of the present invention;  
       FIG. 9   a  is a view showing the second embodiment of the present invention which is installed in place; and  
       FIG. 9   b  is a view showing an operation of the second embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
      Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.  
       FIG. 2  is an exploded perspective view showing a portable computer to which a first embodiment of a latch device according to the present invention is applied.  FIGS. 3   a  to  3   c  are front, side and sectional views showing a latch according to the first embodiment of the present invention.  FIG. 4  is a sectional view showing a major portion of the first embodiment of the present invention.  
      Referring to these figures, various parts are installed in a main body  20  of the portable computer, which is formed in a substantially rectangular plate shape. An upper face of the main body  20  is provided with a keyboard  22 . A center of a front end of the upper face of the main body  20  is provided with a touchpad  24  which is a pointing device.  
      Both sides of the front end of the upper face of the main body  20  are provided with catching grooves  26 . The catching grooves  26  are portions into which hooks  64  for engaging the main body  20  and a display  30  are hooked.  
      The display  30  is pivotably connected to a rear end of the main body  20  through a hinge  28 . The display  30  pivots about the hinge  28  to be folded onto the main body  20  or unfolded with respect thereto at a predetermined angle.  
      An appearance of the display  30  is formed by a rear case  31  and a front case  32 . The rear case  31  forms a rear face of the display  30 , while the front case  32  of a rectangular frame shape forms a front edge of the display  30 . The rear case  31  is preferably formed of synthetic resin and not metal in the present embodiment, while an inside thereof except a portion of its front end comprises metal plates.  
      An inside of the display  30  is provided with a liquid crystal panel  33  the edge of which is sealed by the front case  32 . The liquid crystal panel  33  displays image information. Instead of the liquid crystal panel  33 , various display panels may be employed.  
      An evading portion  34  which forms a side of a knob seating groove  46  provided in the rear case  31  is concavely formed at a rear face of a front end of the front case  32 . The front case  32  may also be formed of synthetic resin, and is temporarily assembled to the rear case  31  by means of hook-shaped portions.  
      A plurality of fastening holes  36  for fastening the front case  32  to the rear case  31  are formed through the front case  32 . Hook slots  38  are formed through the front end of the front case  32 . The hooks  64  of a latch  60 , which will be described below, are projected through the hook slots  38 . The hook slots  38  are preferably positioned relatively adjacent to both ends of the front case  32 .  
      An inside of a front end of the rear case  31  is provided with a structure for installing the latch  60  and guiding the movement of the latch  60 , which will be described. First, a side wall  40  having a predetermined height is provided around an edge of the rear case  31 , wherein a projecting piece  42  is relatively projected and is formed at a center of the front end of the rear case  31 . The projecting piece  42  is also stepped relatively inside of the rear case  31  as compared with the other portion of the side wall  40 . The projecting piece  42  is formed with an elongated knob guide slot  44 . The knob seating groove  46  is completed by engaging the evading portion  34  of the front case  32  to the projecting piece  42 .  
      A plurality of fastening bosses  50  are provided in the front end of the rear case  31 . The fastening bosses  50  are formed at positions corresponding to the fastening holes  36  of the front case  32 . A fastening aperture in which a thread is formed is vertically formed through a center of each fastening boss  50 .  
      An inner face of the front end of the rear case  31  is provided with guide hooks  52 . The guide hooks  52  are projected vertically from the inner face of the rear case  31 , wherein a catching projection  53  extends at a right angle from a front end of each guide hook  52 . The catching projections  53  are seated on a side of the latch  60 , which will be described below, and then, define an installation position of the latch  60  and guide movement thereof. The guide hooks  52  are formed not to interfere with the latch  60  along a movement trace of the latch  60 .  
      The inner face of the front end of the rear case  31  is provided with a guide stopper  56  not to interfere with the latch  60  on the movement trace of the latch  60 . The guide stopper  56  vertically extends from the inner face of the rear case  31 , and then extends by a predetermined length from its front end in parallel with the inner face so as to define the installation position of the latch  60  and guide the movement of the latch  60 .  
      Further, the inner face of the front end of the rear case  31  is provided with a plurality of supporting knobs  58  along the movement trace of the latch  60 . The supporting knobs  58  are in direct contact with a side of the latch  60 , and then, support it. The supporting knobs  58  are formed to be elongated perpendicularly to the moving direction of the latch  60 , wherein the degree of projection thereof from the inner face of the rear case  31  can vary. This is to compensate a curved surface having some curvature of the front end of the rear case  31  when it is formed in the curved surface. Therefore, if the corresponding portions of the rear case  31  are flat, the supporting knobs  58  need not be provided.  
      Guide pieces  59  are formed in order to guide both opposite surfaces of the latch  60  guided by the guide hooks  52  or the guide stopper  56 . The guide pieces  59  are provided at positions corresponding to between the fastening bosses  50  and the guide hooks  52 . The guide pieces  59  are formed so as to be projected vertically from the inner surface of the rear case  31 .  
      A latch body  61  of the latch  60  is formed in an elongated bar shape. The latch body  61  has a length corresponding to at least a distance between the hook slots  38  of the front case  32 . The latch body  61  has a cross section of a substantially rectangular shape and is formed to be hollow and opened to a face thereof. An inside of the latch body  61  is provided with a plurality of partitions  62  for reinforcing the latch body  61 .  
      Both ends of the latch body  61  are formed with the hooks  64 . A front end of each hook  64  is projected at a predetermined length in a direction of the length of the latch body  61 , and then, is selectively hooked into each catching groove  26  of the main body  20 . It is preferred that the hooks  64  be formed at positions adjacent to both the ends of the latch body  61 .  
      An end of the latch body  61  is formed with a restoring member hook  65 . An end of a restoring member  80 , which will be described below, is hooked onto the restoring member hook  65 , causing an elastic force to be applied to the latch body  61 .  
      At least two positions of the latch body  61  are formed with respective moving guides  66 . The moving guides  66  are formed in an intermediate portion of the latch body  61 , wherein a guide slot  68  is vertically formed through an inside of each moving guide  66 . The fastening bosses  50  are positioned in the guide slots  68 , respectively. Therefore, the movement of the latch  60  is guided by the guide slots  68  and the fastening bosses  50 . To this end, the guide slot  68  is formed to be elongated more than a diameter of the fastening bosses  50 , providing a stroke for the hooks  64  to be hooked into or unhooked from the catching grooves  26 .  
      A knob fixing slot  70  is formed through a corresponding face of the center of the latch body  61 . The knob fixing slot  70  is formed on a surface perpendicular to a surface in which the hooks  64  are formed. That is, the knob fixing slot  70  is formed at a position corresponding to the knob guide slot  44  of the knob seating groove  46 .  
      The latch body  61  is formed with steps  72  at positions corresponding to the guide hooks  52 , respectively. The steps  72  are formed relatively lower than the other portions of the latch body  61 . Therefore, the catching projections  53  of the guide hooks  52  are seated in the steps  72 , respectively, and then, guide the movement of the latch body  61 . At least one of the steps  72  is preferably formed over an area corresponding to the movement trace of the latch body  61 .  
      As shown in  FIG. 4 , the latch body  61  is formed with hook holes  74  and a guide hole  76  at a portion corresponding to the knob fixing slot  70 . An assembly guide pin  95  and catching hooks  93  of an operating knob  90 , which will be described below, are inserted into the guide hole  76  and the hook holes  74 , respectively. The guide hole  76  is formed at a position more adjacent to any one of the hook holes  74 .  
      The restoring member  80  functions to pull the latch  60  in a certain direction. The restoring member  80  may comprise a tensile coil spring. The restoring member  80  generates the elastic force in the direction in which the hooks  64  of the latch  60  are hooked into the catching grooves  26  of the main body  20 .  
      A side of the rear case  31  is formed with a catching portion  82 . The catching portion  82  is a portion onto which the other end of the restoring member  80  is hooked. The catching portion  82  is formed at a position spaced apart by a predetermined distance from an end of the movement trace of the latch  60 .  
      The operating knob  90  is a portion to which a force for moving the latch  60  is transmitted. A knob body  91  of the operating knob  90  is positioned at the inside of the rear case  31  corresponding to a lower portion of the projecting piece  42 . Both ends of the knob body  91  are provided with the catching hooks  93 , which pass through the knob fixing slot  70  and then are hooked into the hook holes  74 , respectively. A front end of each of the catching hooks  93  is provided with a catching projection  94  and is hooked into the hook hole  74  with some elastic deformation.  
      A side of the knob body  91  is formed with the assembly guide pin  95 . The assembly guide pin  95  extends by a predetermined length in parallel with the extending direction of the catching hooks  93  and formed to be biased toward any one of the catching hooks  93 . The assembly guide pin  95  functions to guide the direction of assembling the operating knob  90  to the latch  60 .  
      A side of the knob body  91  is provided with a knob portion  97 . The knob portion  97 , the surface of which is preferably provided with a means for preventing a slip, is seated in the knob seating groove  46 . The knob portion  97  is a portion through which a user operates the operating knob  90 .  
      Next, a second embodiment of present invention is shown in FIGS.  6  to  8   a  and  8   b . According to the figures, various parts are installed in a main body  120  of the portable computer, which is formed in a substantially rectangular plate shape. An upper face of the main body  120  is provided with a keyboard  122 . A center of a front end of the upper face of the main body  120  is provided with a touchpad  124  which is a pointing device.  
      Both sides of the front end of the upper face of the main body  120  are provided with catching grooves  126 . The catching grooves  126  are portions into which hooks  164  for engaging the main body  120  and a display  130  are hooked.  
      The display  130  is pivotably connected to a rear end of the main body  120  through a hinge  128 . The display  130  pivots about the hinge  128  to be folded onto the main body  120  or unfolded with respect thereto at a predetermined angle.  
      An appearance of the display  130  is formed by a rear case  131  and a front case  132 . The rear case  131  forms a rear face of the display  130 , while the front case  132  of a rectangular frame shape forms a front edge of the display  130 . The rear case  131  is preferably formed of synthetic resin and not metal in the present embodiment, while an inside thereof except a portion of its front end comprises metal plates.  
      An inside of the display  130  is provided with a liquid crystal panel  133  the edge of which is sealed by the front case  132 . The liquid crystal panel  133  displays image information. Instead of the liquid crystal panel  133 , various display panels may be employed.  
      As shown in  FIG. 7 , a curved surface having a predetermined width in a direction of the rear case  131  is formed around an edge of the front case  132 , wherein a center of a front end of the front case  132  in the curved surface is formed with a concave groove  134 . A side of the concave groove  134  is provided with an evading slot  135 . A projecting piece  143 , which will be described below, is seated in the evading slot  135 .  
      The front case  132  may be provided with a plurality of hook-shaped portions for temporary assembly with the rear case  131 . A plurality of fastening holes  136  for securely fastening the front case  132  to the rear case  131  are formed through the front case  132 . Hook slots  138  are formed through the front end of the front case  132 . Hooks  164  of a latch  160 , which will be described below, are projected through the hook slots  138 . The hook slots  138  are preferably positioned relatively adjacent to both ends of the front case  132 .  
      An inside of a front end of the rear case  131  is provided with a structure for installing the latch  160  and guiding the movement of the latch  160 , which will be described. First, an antenna cover  140  is installed at an edge of the front end of the rear case  131 . The antenna cover  140  is formed with a curved surface toward the front case  132 . The curved surfaces of the antenna cover  140  and the front case  132  cooperate with each other to form a front face of the display  130 . For reference, the antenna cover  140  may be integrally formed in the rear case  131 . However, in the present embodiment, the antenna cover  140  is formed separately from the rear case  131 , and is engaged with the rear case  131  so as to form a portion of the rear case  131 .  
      The antenna cover  140  is formed with a concave groove  142  at a position corresponding to the concave groove  134  of the front case  132 . The projecting piece  143  is projected and formed in a side in which the concave groove  142  is formed. The projecting piece  143  is positioned at the evading slot  135  of the front case  132 . The projecting piece  143  forms an end of a knob-moving slot  144 , which will be described below, and then, is hooked onto a connecting neck  192  of an operating knob  190  in order to temporarily assemble the latch  160  when the latch  160  which will be described below is assembled.  
      If the concave groove  134  of the front case  132  and the concave groove  142  of the antenna cover  140  are engaged with each other, a groove in which the operating knob  190  which will be described below is seated is formed. In addition, since some of portions in which the concave grooves  134  and  142  of the front case  132  and the antenna cover  140  are formed are relatively less projected, the knob-moving slot  144  is formed by engaging the front case  132  and the antenna cover  140  to each other. Herein, the projecting piece  143  forms a portion of the knob-moving slot  144  at a side of the front case  132 .  
      A plurality of fastening bosses  150  are provided in the front end of the rear case  131 . The fastening bosses  150  are formed at positions corresponding to the fastening holes  136  of the front case  132 . The fastening aperture in which a thread is formed is vertically formed through the center of each fastening boss  150 .  
      The inside of the front end of the rear case  131  is formed with a restoring member support  152 . The restoring member support  152  is formed with a guide slot  154 . The guide slot  154  is formed through the restoring member support  152  and opened to an upper end of the restoring member support  152 .  
      A latch body  161  of the latch  160  is formed in an elongated bar shape. The latch body  161  has a length corresponding to at least a distance between the hook slots  138  of the front case  132 . The latch body  161  is formed in a substantially elongated plate shape.  
      Both ends of the latch body  161  are formed with the hooks  164 . A front end of each hook  164  is projected at a predetermined length in the direction of the length of the latch body  161 , and then, is selectively hooked into each catching groove  126  of the main body  120 . It is preferred that the hooks  164  be formed at positions adjacent to both the ends of the latch body  161 .  
      An end of the latch body  161  is formed with a restoring member hook  165 . An end of a restoring member  180 , which will be described below, is hooked onto the restoring member hook  165 , causing an elastic force to be applied to the latch body  161 . In the restoring member hook  165 , a hook rod  165   s  is formed in the direction of the length of the latch body  161  in a hook penetrating section  165 ′ which is formed through the latch body  161 . The hook rod  165   s  is shorter than the hook penetrating section  165 ′.  
      At least two positions of the latch body  161  are formed with respective moving guides  166 . The moving guides  166  are formed in an intermediate portion of the latch body  161 , wherein a guide slot  168  is vertically formed through an inside of each moving guide  166 . The fastening bosses  150  are positioned in the guide slots  168 , respectively. Therefore, the movement of the latch  160  is guided by the guide slots  168  and the fastening bosses  150 . To this end, the guide slot  168  is formed to be elongated more than a diameter of the fastening bosses  150 , providing a stroke for the hooks  164  to be hooked into or unhooked from the catching grooves  126 .  
      The latch body  161  is provided with a plurality of interference avoiding portions  170  for preventing interference with parts installed around the latch  160 . While some of the interference avoiding portions  170  are formed through the center of the latch body  161 , the others are cut off to be opened to a side of the latch body  161 .  
      The restoring member  180  functions to pull the latch  160  in a certain direction. The restoring member  180  may comprise a compressive coil spring. The restoring member  180  generates the elastic force in the direction in which the hooks  164  of the latch  160  are hooked into the catching grooves  126  of the main body  120 .  
      The operating knob  190  is a portion to which a force for moving the latch  160  is transmitted. The operating knob  190  is formed integrally with the latch body  161  in the present embodiment. The connecting neck  192  is provided between the operating knob  190  and the latch body  161 . The connecting neck  192  is positioned in the knob-moving slot  144 . A surface of the operating knob is preferably provided with a means for preventing a slip.  
      Hereinafter, an operation of the latch device of the portable computer according to the present invention constructed as above will be described in detail.  
      First, in the first embodiment, an assembly process of the latch  60  and the operating knob  90  will be described. The latch  60  is seated in the inner face of the front end of the rear case  31 . That is, the movement of the latch  60  is guided by the fastening bosses  50 , the guide hooks  52 , the guide stopper  56  and the guide pieces  59 .  
      The fastening bosses  50  are seated in the guide slots  68  of the moving guides  66  of the latch  60 , respectively. The guide hooks  52  are brought into contact with a surface of the latch body  61  and a surface perpendicular thereto, respectively. Particularly, the catching projections  53  of the guide hooks  52  are seated on the steps  72 , respectively. The guide stopper  56  functions to guide a surface of the latch body  61  at the end of the latch body  61 , and at the same time, guide the latch body  61  not to move in the direction opposite to the inner face of the rear case  31 . The guide pieces  59  are in contact with a surface of the latch body  61  which is opposite to the guide hooks  52  and the guide stopper  56 . Such a state is shown in  FIG. 5   a.    
      The end of the restoring member  80  is caught onto the restoring member hook  65  at the end of the latch body  61 . The other end of the restoring member  80  is caught onto the catching portion  82  of the rear case  31 , so that the restoring member  80  always pull the latch body  61  left with respect to  FIG. 5   a.    
      Next, the operating knob  90  is mounted in the latch body  61 . The operating knob  90  passes through the knob guide slot  44  of the knob seating groove  46 , and then, the knob body  91  is inserted thereinto. At this time, the knob portion  97  is seated onto an upper face of the projecting piece  42 . The knob body  91  of the operating knob  90 , which passes through the knob guide slot  44 , is inserted into the knob fixing slot  70  formed in the latch body  61 .  
      Then, the catching hooks  93  formed in the knob body  91  are hooked into the hook holes  74 , respectively. At this time, the assembly guide pin  95  is inserted into the guide hole  76 . If the operating knob  90  is assembled reversely, the assembly guide pin  95  cannot be inserted into the guide hole  76 . It is the reason why the assembly guide pin  95  is formed relatively more adjacent to the one of the catching hooks  93  and the guide hole  76  is also formed more adjacent to the one of the hook holes  74 . The assembled state of the operating knob  90  is shown in  FIG. 5   b.    
      In addition, after all necessary parts such as the liquid crystal panel  33  are installed in the display  30 , the front case  32  is assembled. The front case  32  and the rear case  31  are temporarily assembled by the hook-shaped portions, and then, engaged to each other by tightening screws, which pass through the fastening holes  36 , to the fastening bosses  50 .  
      Next, an operation of the latch device of the first embodiment of the present invention will be described. When the display  30  is folded onto the main body  20 , front ends of the hooks  64  are guided along one sides of the catching grooves  26 , respectively, and then, the latch body  61  moves right with respect to the figure, while overcoming the elastic force of the restoring member  80 .  
      Then, if the hooks  64  are fully hooked into the catching grooves  26 , the latch body  61  moves to its initial position by the elastic force of the restoring member  80 , and the main body  20  and the display  30  are engaged to each other.  
      In such a state, in order to release the engagement of the main body  20  and the display  30 , the user should operate the operating knob  90 . That is, the knob portion  97  of the operating knob  90  is caused to move in the knob seating groove  46 . If the operating knob  90  moves, the latch  60  moves together. Thus, the latch body  61  moves while guided by means of the fastening bosses  50 , the guide hooks  52 , the guide stopper  56  and the guide pieces  59 . At this time, the latch body  61  moves while overcoming the elastic force of the restoring member  80 .  
      Due to the movement of the latch body  61 , the engagement between the hooks  64  and the catching grooves  26  is released. Although the movement of the latch body  61  causes the engagement to be simply released, the hooks  64  do not get out of the catching grooves  26 . That is, if the user rotates the display  30  about the hinge  28  with respect to the main body  20 , the hooks  64  get out of the catching grooves  26 .  
      In addition, if the user removes a force applied to the operating knob  90 , the latch body  61  moves to its initial position shown in  FIG. 5   b  by the elastic force of the restoring member  80 .  
      Next, in the second embodiment of the present invention, the latch  160  is installed in the rear case  131  so that the fastening bosses  150  are seated in the guide slots  168  of the moving guides  166 , respectively. At this time, the operating knob  190  integrally formed in the latch body  161  is seated in the concave groove  142  with a portion of the connecting neck  192  hooked in the projecting piece  143  of the antenna cover  140 . Here, the projecting piece  143  functions to make the latch body  161  be temporarily assembled.  
      Then, in the latch  160 , the restoring member hook  165  is previously provided with the restoring member  180 . The restoring member  180  has been caught onto the hook rod  165   s . With the restoring member  180  caught onto the hook rod  165   s , the other end of the restoring member  180  is supported by the restoring member support  152 . Since the hook rod  165   s  is positioned in the guide slot  154 , the hook rod  165   s  does not interfere with the restoring member support  152  when the latch body  161  moves.  
      Accordingly, the latch body  161  tends to move in the direction opposite to an arrow shown in  FIG. 9   a , that is, the direction in which the hooks  164  are hooked into the catching grooves  126 , by the elastic force of the restoring member  180 .  
      Then, the front case  132  is engaged to the rear case  131 . The hooks  164  should be projected through the hook slots  138 . Of course, it is performed after the various parts of the display  130  are installed into the rear case  131 . The front case  132  and the rear case  131  are engaged to each other by tightening screws, which pass through the fastening holes  136 , to the fastening bosses  150 .  
      Next, an operation of the latch device of the second embodiment of the present invention will be described. When the display  130  is folded onto the main body  120 , front ends of the hooks  164  are guided along one sides of the catching grooves  126 , respectively, and then, the latch body  161  moves right with respect to  FIG. 9   a , while overcoming the elastic force of the restoring member  180 .  
      Further, if the hooks  164  are fully hooked into the catching grooves  126 , the latch body  161  moves to its initial position by the elastic force of the restoring member  180 , and then, the main body  120  and the display  130  are engaged to each other.  
      In such a state, in order to release the engagement of the main body  120  and the display  130 , the user should operate the operating knob  190 . That is, the operating knob  190  is caused to move in the concave grooves  134  and  142 . If the operating knob  190  moves, the latch  160  moves together. Since the fastening bosses  150  are positioned in the guide slots  168  of the moving guides  166 , the fastening bosses  150  are guided by the guide slots  168 , causing the movement of the latch body  161  to be guided.  
      At this time, the latch body  161  moves while overcoming the elastic force of the restoring member  180 . Due to the movement of the latch body  161 , the engagement between the hooks  164  and the catching grooves  126  is released. Such a state is shown in  FIG. 9   b.    
      Although the movement of the latch body  161  causes the engagement to be simply released, the hooks  164  do not get out of the catching grooves  126 . That is, if the user rotates the display  130  about the hinge  128  with respect to the main body  120 , the hooks  164  get out of the catching grooves  126 .  
      In addition, if the user removes a force applied to the operating knob  190 , the latch body  161  moves to its initial position shown in  FIG. 9   a  by the elastic force of the restoring member  180 .  
      According to the latch device of the portable computer of the present invention as described above, the following advantages can be expected.  
      The latch device of the present invention is constructed so that the latch body having two hooks is operated by the single operating knob. Thus, the user can release the engagement of the main body and the display by only one hand, causing the operation to be relatively easy.  
      Further, in the present invention, at least two moving guides are formed in the intermediate portion of the latch body, and the fastening bosses of the rear case are seated in the guide slots formed in the moving guides. Thus, the movement of the latch body is guided, and at the same time, the latch body can be securely positioned in the rear case. Accordingly, since the latch body may be relatively elongated, the hooks are positioned at both ends of the display with relatively large dimensions so that the main body and the display can be securely engaged to each other.  
      In the meantime, since the fastening bosses positioned in the guide slots of the latch body also function to fasten the rear case and the front case to each other, an inner space of the display can be effectively used. Particularly, the installation position of the latch body can be securely defined while the fastening bosses are engaged to the front case.  
      In addition, according to the present invention, since the operating knob is formed integrally with the latch, the number of the parts of the latch can be reduced, and then, an assembling process thereof can be simplified, causing manufacturing costs to be reduced.  
      The scope of the present invention is not limited to the embodiments described and illustrated above but is defined by the appended claims. It will be apparent that those skilled in the art can make various modifications and changes thereto within the scope of the invention defined by the claims.  
      For example, the order of the fastening bosses  50 , the guide hooks  52 , the guide stopper  56  and the guide pieces  59  is not important if the movement of the latch body  61  can be guided.  
      Furthermore, although the latch  60  is installed in the rear case  31  in the first embodiment of the present invention, a portion in which the latch  60  is installed may be the antenna cover (not shown), which is provided at the front end of the rear case  31  and then forms a portion of the rear case  31 .  
      Also, the knob-moving slot  144  for moving the operating knob  190  is formed by the front case  132  and the antenna cover  140  in the second embodiment of the present invention, but not necessarily so. If the antenna cover  140  is integrated with the rear case  131 , the knob-moving slot is formed by the rear case  131  and the front case  132 .