Patent Publication Number: US-2005115025-A1

Title: Electronic apparatus having a rotatable display unit and hinge device used for the same

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
      This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2003-400892, filed Nov. 28, 2003, the entire contents of which are incorporated herein by reference.  
     BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      This invention relates to an electronic apparatus, such as a portable computer, having a rotatable display unit. This invention also relates to a structure of a hinge device which rotatably supports a display unit.  
      2. Description of the Related Art  
      Portable computers, which are an example of an electronic apparatus, have a main unit having a keyboard and a display unit having a liquid crystal display. The display unit is rotatably supported by the main unit with a hinge device interposed therebetween.  
      The hinge device has a first bracket, a second bracket and a hinge shaft. An end of the hinge shaft is rotatably supported by the first bracket. The other end of the hinge shaft is fixed onto the second bracket. Therefore, the first bracket and the second bracket are relatively rotatable around the axis of the hinge shaft.  
      The main unit of portable computers has, for example, a base that supports a printed wiring board with a CPU, and a top cover covering the base. The display unit having an LCD cover that supports the liquid crystal display, and an LCD mask covering the LCD cover.  
      In conventional portable computers, the first bracket of the hinge device is fixed to an internal surface of the top cover by screws, and the second bracket is fixed to an internal surface of the LCD cover by screws. Therefore, in the step of assembling the portable computers, the top cover and the LCD cover are connected with the hinge device interposed therebetween to form an assembly. Japanese Patent No. 3382073 discloses such a portable computer.  
      According to the conventional portable computers, the hinge device is formed as one unitary piece with the top cover and the LCD cover. Therefore, the hinge device is a large-scale structure corresponding to the size of the portable computers. As a result, the hinge device obstructs assembling of the portable computer, and is a factor which deteriorates assembling workability of the portable computers.  
      To improve it, it is one choice to remove the first bracket of the hinge device from the top cover of the main unit to separate the top cover and the hinge device. Adopting this structure necessitates a step of fixing the first bracket of the hinge device to the base or top cover of the main unit by screws in assembling the portable computer.  
      Since the hinge device comes with the LCD cover, the heavy large LCD cover is located on the other side of the first bracket. Therefore, in temporarily fixing the first bracket onto the base or top cover, the hinge device may be inclined or fall down due to the weight of the LCD cover.  
      This makes temporal fixing of the first bracket difficult. Further, it is necessary to hold the LCD cover by hand in fixing the first bracket to the base or top cover by screws. This requires much time and labor in assembling of the portable computer, and cannot provide an effective measure to improve the workability.  
     BRIEF SUMMARY OF THE INVENTION  
      According to an embodiment of the present invention, there is provided an electronic apparatus comprises: a first housing; a second housing separate from the first housing; and a hinge device which rotatably connects the first housing with the second housing. The hinge device includes a first bracket to be fixed to the first housing, a second bracket to be fixed to the second housing, and a hinge shaft which connects the first bracket and the second bracket such that the first and second brackets are relatively rotatable. The first housing has a holding portion in a position corresponding to the first bracket, and the holding portion catches the first bracket and thereby holds the hinge device accompanied with the second housing on the first housing. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING  
      The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention, and together with the general description given above and the detailed description of the embodiments given below, serve to explain the principles of the invention.  
       FIG. 1  is a perspective view of a portable computer according to an embodiment of the present invention.  
       FIG. 2  is a perspective view of the portable computer according to the embodiment of the present invention, illustrating the state where a main unit and a display unit are separated.  
       FIG. 3  is a perspective view of a first hinge device according to the embodiment of the present invention.  
       FIG. 4  is a perspective view of a second hinge device according to the embodiment of the present invention.  
       FIG. 5  is a perspective view illustrating a positional relationship between the second hinge device fixed on an LCD cover and a base of the main unit in the embodiment of the present invention.  
       FIG. 6  is a perspective view illustrating a state where the first hinge device is fixed to the base of the main unit in the embodiment of the present invention.  
       FIG. 7  is a perspective view illustrating a state where the second hinge device is fixed to the base of the main unit in the embodiment of the present invention.  
       FIG. 8  is a plan view illustrating a state where the first hinge device is fixed to the base of the main unit in the embodiment of the present invention.  
       FIG. 9  is a cross-sectional view taken along a line F 9 -F 9  in  FIG. 8 .  
       FIG. 10  is a cross-sectional view taken along a line F 10 -F 10  in  FIG. 8 .  
       FIG. 11  is a perspective view illustrating a state where the first hinge device is temporarily fixed to the base of the main unit in the embodiment of the present invention.  
       FIG. 12  is a perspective view illustrating a state where the second hinge device is temporarily fixed to the base of the main unit in the embodiment of the present invention.  
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      An embodiment of the present invention is explained on the basis of drawings in which the present invention is applied to a portable computer.  
       FIGS. 1 and 2  disclose a portable computer  1  which is an example of an electronic apparatus of the present invention. The portable computer  1  comprises a main unit  2  and a display unit  3 . The main unit  2  has a flat box-shaped first housing  4 . The first housing  4  is formed of a metallic material such as magnesium alloy, and has a bottom wall  4   a , a top wall  4   b , right and left side walls  4   c , a front wall  4   d  and a rear wall  4   e.    
      The first housing  4  comprises a base  5  and a top cover  6 . The base  5  has the bottom wall  4   a , the side walls  4   c , the front wall  4   d  and the rear wall  4   e . The top cover  6  has the top wall  4   b , and covers the base  5  in the state of being detachable from the base  5 .  
      Depressions  7   a  and  7   b  are formed in respective corner portions defined by the side walls  6   c  and the rear wall  4   e  of the first housing  4 . The depressions  7   a  and  7   b  are located in the rear end of the first housing  4 , and apart from each other in the width direction of the first housing  4 .  
      The first housing  4  has a keyboard mounting portion  8  and a battery receiving portion  9 . The keyboard mounting portion  8  is a rectangular recessed portion open to the top surface of the first housing  4 , and supports a keyboard  10 . The battery receiving portion  9  is located in the rear of the keyboard  10 . The battery receiving portion  9  is a rectangular recessed portion open to the bottom wall  4   a , the top wall  4   b  and rear wall  4   e  of the first housing  4 , and supports a detachable battery pack  11 .  
      The display unit  3  has a second housing  13  and a liquid crystal display  14 . The second housing  13  has a flat box-shape having almost the same size as that of the first housing  4 . The second housing  13  has a pair of leg portions  15   a  and  15   b  at one end thereof. The leg portions  15   a  and  15   b  are apart from each other in the width direction of the second housing  13 , and fitted into the depressions  7   a  and  7   b  of the first housing  4 , respectively.  
      The second housing  13  has an LCD cover  16  that supports the liquid crystal display  14 , and an LCD mask  17  covering the LCD cover  16 . The liquid crystal display  14  has a screen  14   a  that displays images. The screen  14   a  is exposed to the outside of the second housing  13  through an opening  18  formed in the LCD mask  17 .  
      As shown in  FIG. 2 , the base  5  of the first housing  4  has a pair of hinge support portions  20   a  and  20   b . One hinge support portion  20   a  is located between the left depression  7   a  and a left end portion of the battery receiving portion  9 . The other hinge support portion  20   b  is located between the right depression  7   b  and a right end portion of the battery receiving portion  9 . The hinge support portions  20   a  and  20   b  support the display unit  3 , with metallic first and second hinge devices  21  and  22  interposed therebetween, respectively.  
      The display unit  3  is rotatable between an opened position and a closed position. In the closed position, the display unit  3  lies on the main unit  2  to cover the keyboard  10  from above. In the opened position, the display unit  3  is stood on the rear end portion of the main unit  2  to expose the keyboard  10  and the screen  14   a.    
      The first hinge device  21  extends between the hinge support portion  20   a  of the base  5  and the left leg portion  15   a  of the second housing  13 . The second hinge device  22  extends between the other hinge portion  20   b  of the base  5  and the right leg portion  15   b  of the second housing  13 .  
      The first and second hinge devices  21  and  22  have the same structure, and are fixed to the first and second housings  4  and  13 , respectively, in the same manner.  
      As shown in  FIGS. 3 and 4 , each of the first and second hinge devices  21  and  22  has a first bracket  25 , a second bracket  26  and a hinge shaft  27 . The first brackets  25  of the hinge devices  21  and  22  are located on the hinge support portions  20   a  and  20   b  of the base  5 , respectively.  
      As shown in  FIGS. 5 and 9 , each of the hinge support portions  20   a  and  20   b  has a boss portion  29  having a screw hole  28 , a support wall  30  and a positioning pin  31 . In each of the hinge support portions  20   a  and  20   b , the boss portion  29 , the support wall  30  and the positioning pin  30  project upward from the bottom wall  4   a  of the base  5 , and are arranged in line along the width direction of the base  5 . The top end of the boss portion  29  and the top end of the support wall  30  are located on the same plane. The top end of the positioning pin  31  projects higher than the top ends of the boss portion  29  and the support wall  30 .  
      The first bracket  25  has a plate shape having a size enough to be superposed on the top ends of the boss portion  29  and the support wall  30 . The first bracket  25  has an insertion hole  32  that conforms to the screw hole  28 , and an engagement hole  33  serving as an engaging portion into which the positioning pin  31  is fitted.  
      Further, the first bracket  25  has a bearing portion  34  and a fixing piece  35 . The bearing portion  34  is perpendicularly bent upward from one end of the first bracket  25 , and opposed to the depression  7   a  or  7   b  inside the base  5 . The fixing piece  35  is bent upward from the other end of the first bracket  25 , and opposed to the rear wall  4   e  of the base  5 . A screw hole  37  to communicate with an insertion hole  36  opened in the rear wall  4   e  is formed in a top end portion of the fixing piece  35 .  
      As shown in FIGS.  6  to  8 , the first brackets  25  of the first and second hinge devices  21  and  22  are fixed to the hinge support portions  20   a  and  20   b  of the base  5 , respectively. Each of the first brackets  25  is fixed by two screws  38  and  39 . One screw  38  is screwed into the screw hole  28  of the boss portion  29  from above the base  5  through the insertion hole  32 . The other screw  39  is screwed into the screw hole  37  from the rear of the base  5  through the insertion hole  36 . Therefore, each of the first brackets  25  is supported by both the bottom wall  4   a  and the rear wall  4   e  of the base  5 .  
      As typically shown by the second hinge device  22  in  FIG. 5 , the second bracket  26  is fixed to an internal surface of the side wall  16   a  of the LCD cover  16  by a screw (not shown). The second bracket  26  has a bearing portion  40  at one end. The bearing portion  40  is located inside the leg portion  15   b  of the second housing  13 .  
      The hinge shaft  27  extends between the bearing portion  34  of the first bracket  25  and the bearing portion  40  of the second bracket  26 , and is horizontally arranged along the width direction of the portable computer  1 . One end of the hinge shaft  27  is fixed to the bearing portion  40  of the second bracket  26 . The other end of the hinge shaft  27  is connected to the bearing portion  34  of the first bracket  25  to be rotatable around the axis thereof. A brake mechanism  41  that restricts free rotation of the hinge shaft  27  is incorporated into the connecting portion. Therefore, the first bracket  25  and the second bracket  26  are relatively rotatable around the axis of the hinge shaft  27 .  
      In the step of assembling the portable computer  1 , the first and the second hinge devices  21  and  22  are attached to the LCD cover  16 . Therefore, the first and second hinge devices  21  and  22  and the display unit  3  are unitized as one assembly. Therefore, as shown in  FIG. 2 , the hinge shafts  27  of the first and second hinge devices  21  and  22  project from the leg portions  15   a  and  15   b , respectively, to the outside of the second housing  13 , and the first brackets  25  of the hinge devices  21  and  22  are located between the leg portions  15   a  and  15   b.    
      The first brackets  25  of the first and second hinge devices  21  and  22  accompanied with the display unit  3  are fitted to the hinge support portions  20   a  and  20   b  of the base  5 , respectively. Specifically, the first brackets  25  are guided into the hinge support portions  20   a  and  20   b  with the display unit  3  stood, and fixed to the hinge support portions  20   a  and  20   b  by screws  38  and  39 .  
      Each of the first brackets  25  has a fitting portion  43  at the other end thereof opposite to that having the bearing portion  34 . The fitting portion  43  is perpendicularly bent downward from the other end of the first bracket  25 , and has a hook portion  44  at its bottom end. The hook portion  44  has a size larger than that of the fitting portion  43  in the depth direction of the base  5 .  
      Each of the hinge support portions  20   a  and  20   b  of the base  5  has a holding portion  46  in a position corresponding to the other end of the first bracket  25 . The holding portion  46  has first and second wall portions  47   a  and  47   b . The first and second wall portions  47   a  and  47   b  project upward from the bottom wall  4   a  of the base  5 , and are opposed to each other in the depth direction of the base  5 . Therefore, the first and second wall portions  47   a  and  47   b  are arranged in a line along the direction perpendicular to the axis of the hinge shaft  27 .  
      In the state where the first bracket  25  is superposed on the top ends of the boss portion  29  and the support wall  30 , the hook portion  44  located at the other end of the first bracket  25  is fitted between the first and second wall portions  47   a  and  47   b . In other words, the first and second wall portions  47   a  and  47   b  hold the hook portion  44  therebetween from the front and the rear of the base  5 . Thereby, the first bracket  25  is held by the hinge support portions  20   a  and  20   b , in the state where movement of the base  5  in the depth direction is restrained.  
      Further, the first and second wall portions  47   a  and  47   b  are connected to each other, with a third wall portion  48  interposed therebetween. The third wall portion  48  projects upward from the bottom wall  4   a  of the base  5 , and extends between ends of the first and second wall portions  47   a  and  47   b . The third wall portion  48  secures sufficient strength of the first and second wall portions  47   a  and  47   b.    
      The following is explanation of a procedure of connecting the display unit  3  to the main unit  2 , in the portable computer  1  having the above structure.  
      As shown in  FIG. 2 , first, the display unit  3  is maintained in a stood position with respect to the first brackets  25  of the first and second hinge devices  21  and  22 . In this state, the first brackets  25  are guided into the hinge support portions  20   a  and  20   b  in the rear end portion of the base  5 .  
      In this step, as shown in  FIGS. 11 and 12 , the positioning pins  31  projecting from the bottom wall  4   a  of the base  5  are inserted into the engagement holes  33  of the first brackets  25 . Further, the hook portions  44  of the first brackets  25  are fitted between the respective first and second wall portions  47   a  and  47   b  projecting from the bottom wall  4   a.    
      Inserting the positioning pins  31  into the engagement holes  33  fixes the positions of the first brackets  25  and the boss portions  29 . This restrains movement of the first brackets  25  in the axial direction of the hinge shafts  27  and the depth direction of the first housing  4 , and the insertion holes  32  of the first brackets  25  match the screw holes  28  of the respective boss portions  29 .  
      Further, as shown in FIGS.  10  to  12 , the hook portions  44  of the first brackets  25  are engaged with the respective first and second wall portions  47   a  and  47   b . The first and second wall portions  47   a  and  47   b  hold the respective hook portions  44  of the first brackets  25  from the front and the rear of the first housing  4 . Thereby, the first brackets  25  are held by the hinge support portions  20   a  and  20   b , and the display unit  3  is prevented from falling down to the front or the rear of the base  5 .  
      Therefore, the first brackets  25  of the first and second hinge devices  21  and  22  are temporarily fixed to the hinge support portions  20   a  and  20   b  of the base  5 , in the state where the display unit  3  is stood.  
      Next, the screws  38  and  39  are screwed into the screw holes  28  and  37  through the insertion holes  32  and  36 . This screwing fixes the first brackets  25  of the first and second hinge devices  21  and  22  to the hinge support portions  20   a  and  20   b  of the base  5 , respectively, and completes connection of the main unit  2  and the display unit  3 .  
      According to the embodiment of the present invention having the above structure, the hinge support portions  20   a  and  20   b  of the first housing  4  have the respective first and second wall portions  47   a  and  47   b  which hold the first brackets  25  of the first and second hinge devices  21  and  22  therebetween, respectively.  
      Therefore, until the first brackets  25  of the first and second hinge devices  21  and  22  are fixed to the hinge portions  20   a  and  20   b  by the screws  38  and  39 , the first brackets  25  are temporarily fixed to the hinge support portions  20   a  and  20   b , to prevent the display unit  3  from falling down to the front or the rear of the main unit  2 .  
      This unnecessitates supporting the display unit  3  with the operator&#39;s hand while the first brackets  25  are fixed to the hinge support portions  20   a  and  20   b  by the screws  38  and  39 . Therefore, it is possible to easily perform assembly operation of the portable computer  1 .  
      Further, according to the above structure, the base  5  on which the first brackets  25  are fixed is formed of metal having stiffness higher than that of synthetic resin. Therefore, the base  5  can sufficiently withstand the force applied from the first brackets  25  when the display unit  3  is rotated. Thus, it has the advantage that it is possible to reduce the size and weight of the connecting portions between the base  5  and the first brackets  25 , and contribute to compactification of the first brackets  25 .  
      Although each of the fitting portions of the first brackets are inserted between the first and second wall portions which are stood on the bottom wall of the base in the above embodiment, the present invention is not limited to it. For example, concave portions each having supporting surfaces facing each other are formed in the bottom wall of the base, and the fitting portions of the first brackets are inserted between the supporting surfaces of the respective concave portions.  
      Further, the electronic apparatus of the present invention is not limited to portable computers. For example, the present invention can be carried out in the same manner in DVD players having an openable liquid crystal monitor.  
      Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.