Abstract:
The present invention relates to a portable terminal device, such as a cellular phone, which has a screen display section, such as an LCD module, in its upper part and a key manipulation section having an array of plural keys in its lower part. The portable terminal device has a removable battery and is highly protected from water especially in a battery area. There is provided a pair of inner housings, that are a backside inner housing and a front side inner housing, which form a battery compartment having an opening for battery insertion/removal. A key manipulation sheet is disposed on the front side inner housing, and the whole components are covered with a pair of outer housings.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to a portable terminal device, such as a cellular phone, which has a block-like screen display section, such as an LCD module, in its upper part and a sheet-like key manipulation section having an array of plural keys in its lower part.  
           [0003]    2. Description of the Related Art  
           [0004]    In recent years, portable terminal devices including cellular phones have become widely used. Some of these portable terminal devices have various additional capabilities, for example, are made waterproof.  
           [0005]    In conventional waterproof portable terminal devices, a battery pack is located externally, and a cover is placed over the battery that is once mounted. Such a configuration requires a large-area and large-scale mechanism to hold the battery pack, protect it from water and hermetically seal in it, resulting in larger portable terminal devices.  
           [0006]    Various techniques have been proposed to protect conventional portable terminal devices from water.  
           [0007]    For example, in the patent reference 1, there is proposed an arrangement in which two housings surround an object and a packing is fitted into the gap between the housings engaged with each other.  
           [0008]    In the patent reference 2, there is disclosed a case having an outer part made of a soft resin and an inner part made of a hard resin.  
           [0009]    In these patent references, however, there is no description of a small-sized arrangement which has a removable battery pack and is highly waterproof.  
           [0010]    Patent reference 1: Japanese Patent Laid-Open No. 10-70375  
           [0011]    Patent reference 2: Japanese Patent Laid-Open No. 6-268548  
         SUMMARY OF THE INVENTION  
         [0012]    In view of such circumstances, an object of the present invention is to provide a portable terminal device which has a removable battery and is highly protected from water especially in a battery housing compartment.  
           [0013]    To attain the object described above, the present invention provides a portable terminal device having, in the upper part, a screen display section and, in the lower part, a key manipulation section having an array of a plurality of keys, including:  
           [0014]    a first outer housing that covers the back side of contents including the screen display section and the key manipulation section;  
           [0015]    a second outer housing that covers the front side of contents including the screen display section and the key manipulation section, the first and second outer housings having an outer opening formed at the bottom end thereof;  
           [0016]    a first inner housing that is disposed in the space formed by the first and second outer housings and forms an inner wall of a battery compartment close to the first outer housing, a battery being slided into the battery compartment through the bottom end of the battery compartment;  
           [0017]    a second inner housing that is disposed in the space formed by the first and second outer housings and forms an inner wall of the battery compartment close to the second outer housing, the first and second inner housings having an inner opening for battery insertion/removal formed at the bottom end thereof; and  
           [0018]    a third outer housing serving as a lid for closing the outer and inner openings in an openable manner, in which the key manipulation section is disposed on the second inner housing.  
           [0019]    According to the present invention, a strongly-built battery compartment is provided in the portable terminal device, since the inner housings are disposed in the outer housings. The battery is slided into the battery compartment through the bottom end of the compartment. Thus, the passage connecting the battery compartment to the outside has the minimum possible cross-section and can be readily blocked. Thus, the waterproofing property is improved.  
           [0020]    The key manipulation section is disposed on the second inner housing, and therefore, keys can be easily manipulated with the inner housing serving as a support.  
           [0021]    Preferably, the portable terminal device according to the present invention further includes a circuit board disposed in the first outer housing, the screen display section is disposed on the circuit board at the upper part thereof, and the first inner housing covers the circuit board in cooperation with the first outer housing and surrounds the side faces of the screen display section.  
           [0022]    With such a structure, the circuit board and the screen display section are covered with the housings, and thus, the waterproofing property is further improved.  
           [0023]    Furthermore, in the portable terminal device according to the present invention, a joint between the housings is preferably filled with a filler, or the circuit board is preferably coated with a filler.  
           [0024]    This can further improve the waterproofing property.  
           [0025]    Furthermore, in the portable terminal device according to the present invention, a label may be affixed to or printed on a wall of the third outer housing which constitutes an inner wall of the battery compartment.  
           [0026]    In conventional devices, the label is affixed to the wall of the space accommodating the battery. However, according to the present invention, the battery compartment is opened only at the bottom, so that the label cannot be affixed to or printed on the inside walls of the battery compartment. According to the present invention, there is provided the third outer housing serving as a lid for blocking the opening of the battery compartment, and thus, the label can be affixed to or printed on the inside wall of the third outer housing which constitutes an inside wall of the battery compartment.  
           [0027]    As described above, according to the present invention, there is provided a portable terminal device which has a removable battery and is highly waterproof. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0028]    [0028]FIG. 1 is a perspective view of components of a cellular phone, which is an embodiment of the present invention;  
         [0029]    [0029]FIG. 2 is an exploded perspective view of the cellular phone in an assembly step following the step shown in FIG. 1;  
         [0030]    [0030]FIG. 3 is an exploded perspective view showing an assembly step following the step shown in FIG. 2;  
         [0031]    [0031]FIG. 4 is an exploded perspective view showing an assembly step following the step shown in FIG. 3;  
         [0032]    [0032]FIG. 5 is an exploded perspective view showing an assembly step following the step shown in FIG. 4;  
         [0033]    [0033]FIG. 6 is an exploded perspective view showing an assembly step following the step shown in FIG. 5;  
         [0034]    [0034]FIG. 7 shows a mounting hardware member of a lid viewed from a direction different from that in FIG. 6;  
         [0035]    [0035]FIG. 8 shows the lid viewed from another direction;  
         [0036]    [0036]FIG. 9 illustrates a process of attaching the lid to a main unit;  
         [0037]    [0037]FIG. 10 shows a label affixed to an inner wall of the lid which constitutes an inner wall of a battery compartment; and  
         [0038]    [0038]FIG. 11 is a partial enlarged cross-sectional view of the cellular phone taken along the arrow X-X in FIG. 6. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0039]    Now, an embodiment of the present invention will be described. In the following, a cellular phone, which is an embodiment of a portable terminal device according to the present invention, will be described.  
         [0040]    [0040]FIG. 1 is a perspective view of components of the cellular phone, which is an embodiment of the present invention.  
         [0041]    [0041]FIG. 1 shows a circuit board  10 . The circuit board  10  has a small speaker  11  mounted at the uppermost part thereof and a connector  12  fixed thereto and located toward the upper end from the middle thereof. To the connector  12 , a connector part  22 , which is constituted by a flexible circuit board, of an image display module  20  having an LCD display screen (liquid crystal display screen)  21  is inserted. The image display module  20  is placed on the circuit board  10  at an upper section  10   a.    
         [0042]    In this drawing, the circuit board  10  has, in its lower section  10   b,  a connector  13  for a key manipulation section for entry of a telephone number or the like, a battery armature module  14  to be brought into contact with a battery (not shown) for receiving power, and some other circuit components  15 . Although not shown in this drawing, at the middle area of the lower section  10   b  of the circuit board  10  which is surrounded by these circuit components, there are many other circuit components mounted.  
         [0043]    Among these circuit components mounted at the lower section  10   b  of the circuit board  10 , to the connector  13 , a connector part  31  of a flexible substrate  30  for constituting the key manipulation section is inserted and, thus, the flexible substrate is supplied with electric power.  
         [0044]    [0044]FIG. 2 is an exploded perspective view of the cellular phone in an assembly step following the step shown in FIG. 1.  
         [0045]    In this step, a backside outer housing  40  is fitted to the back surface of the circuit board  10  with the image display module  20  mounted thereon and the flexible substrate  30  plugged into the connector  13  as described above. A backside inner housing  50  is mounted on the front surface of the circuit board  10 . The backside outer housing  40  has channels  41  extending longitudinally along the both sides.  
         [0046]    The backside inner housing  50  has, in its upper section, an opening  51  piercing therethrough and surrounding the image display module  20  and, in its lower section, a recess section  52  to constitute a battery compartment. The recess section  52  has no wall at the bottom end  52   a , providing an opening for battery insertion. The back surface of the backside inner housing  50  is recessed so that a space that accommodates the circuit board  10  is provided between the backside outer housing  40  and the backside inner housing  50  placed on the backside outer housing  40 . In addition, the backside inner housing  50  has flanges  53  to be fitted into the channels  41  at the both sides of the backside outer housing  40 .  
         [0047]    Once the backside outer housing  40  is fitted to the back surface of the circuit board  10 , and the backside inner housing  50  is mounted on the front surface of the circuit board  10 , the circuit board  10  is sealed in between the inner surface of the backside outer housing  40  and the back surface of the backside inner housing  50 , and the image display module  20  mounted on the circuit board  10  is surrounded by the walls constituting the opening  51  at the upper section of the backside inner housing  50 .  
         [0048]    [0048]FIG. 3 is an exploded perspective view showing an assembly step following the step shown in FIG. 2.  
         [0049]    After the circuit board  10  (see FIG. 2) is sandwiched between the backside outer housing  40  and the backside inner housing  50  as described with reference to FIG. 2, a frontside inner housing  60  is placed over the lower section of the backside inner housing  50  where the recess section  52  to constitute the battery compartment is formed. The frontside inner housing  60  has, on its front side, a recess section  61  in which the key manipulation section (not shown in this drawing) is to be placed and, on its back side, a recess section  62  which cooperates with the recess section  52  of the backside inner housing  50  to define the battery compartment. The recess section  62  forming the battery compartment has no wall at the bottom end  62   a , and the bottom end  62   a  and the bottom end  52   a  of the backside inner housing  50  cooperatively provide the opening for inserting/removing a battery to/from the battery compartment.  
         [0050]    [0050]FIG. 4 is an exploded perspective view showing an assembly step following the step shown in FIG. 3.  
         [0051]    After the frontside inner housing  60  is placed over the backside inner housing  50  as shown in FIG. 3, the flexible substrate  30  for constituting the key manipulation section is mounted in the recess section  61  on the front of the front side inner housing  60 . Then, a key manipulation sheet  70 , which also constitutes the key manipulation section and is to turn on/off contacts on the flexible substrate  30 , is mounted on the flexible substrate  30 .  
         [0052]    In FIG. 4, there is shown an opening  80  at the bottom end for inserting/removing a battery into/from the battery compartment, which is formed by the backside inner housing  50  and the frontside inner housing  60 .  
         [0053]    [0053]FIG. 5 is an exploded perspective view showing an assembly step following the step shown in FIG. 4.  
         [0054]    After the key manipulation section consisting of the flexible substrate  30  and the key manipulation sheet  70  is placed on the frontside inner housing  60 , as shown in FIG. 4, a frontside outer housing  90  is placed thereon. The frontside outer housing  90  has a display window  91 , which is fitted with a transparent plastic plate, in its upper section of the frontside outer housing  90  over the image display module  20  (see FIGS.  1  to  4 ) and an array of manipulation elements in its lower section over the key manipulation section (see FIG. 4) consisting of the flexible substrate  30  and the key manipulation sheet  70 , each of the manipulation elements exerting a pressure on the key manipulation sheet  70  when it is pressed, thereby causing a contact on the flexible substrate  30  to conduct electricity.  
         [0055]    [0055]FIG. 6 is an exploded perspective view showing an assembly step following the step shown in FIG. 5.  
         [0056]    [0056]FIG. 6 shows a main unit  100  assembled in the steps shown in FIGS.  1  to  5  and a lid  110 . The main unit  100  has, at the bottom end thereof, the opening  80  for battery insertion/removal which is defined by the backside inner housing  50  and the frontside inner housing  60  and an opening  81  surrounding the opening  80  which is defined by the backside outer housing  40  and the frontside outer housing  90 . The opening  80  for battery insertion/removal defined by the backside inner housing  50  and the frontside inner housing  60  is accommodated in the opening  81  defined by the backside outer housing  40  and the frontside outer housing  90 .  
         [0057]    The lid  110  is to block the opening  80  for battery insertion/removal formed in the main unit  100  in an openable manner. The lid  110  has a hook  111  at one end thereof and a mounting hardware member  112  at the other end thereof.  
         [0058]    Although any retainer for retaining the lid  110  is not shown in FIGS.  1  to  5  described so far, FIG. 6 shows a retainer  102  for retaining the mounting hardware member  112  of the lid  110 .  
         [0059]    [0059]FIG. 7 shows the mounting hardware member of the lid viewed from a direction different from that in FIG. 6, and FIG. 8 shows the lid viewed from another direction. For convenience of mounting or removing the lid  110  on or from the bottom end of the main unit  100 , a part of the lid  110  close to the hook  111  is flexible so that it is bent as shown in FIG. 8 when a force is applied thereto.  
         [0060]    [0060]FIG. 9 illustrates a process of attaching the lid  110  to the main unit  100 .  
         [0061]    The main unit  100  has a retainer  101  for retaining the hook  111  of the lid  110  on one side surface thereof and the retainer  102  for retaining the mounting hardware member  112  of the lid  110  on the other side surface thereof.  
         [0062]    When attaching the lid  110  to the bottom end of the main unit  100 , the hook  111  of the lid  110  is engaged with the retainer  101  of the main unit  100  so that the lid  110  covers the bottom end of the main unit  100 , and the mounting hardware member  112  of the lid  110  is engaged with the retainer  102  of the main unit  100 , as shown in Part (A) of FIG. 9. Then, as shown in Parts (B) and (C) of FIG. 9, a lever  112   a  of the mounting hardware member  112  is rotated to a position where it comes into contact with the main unit  100 .  
         [0063]    On the other hand, when removing the lid  110  from the main unit  100 , the lever  112   a  of the mounting hardware member  112  which is in the position shown in Part (C) of FIG. 9 is rotated to the position shown in Part (B) of FIG. 9, and then, to the position shown in Part (A) of FIG. 9. Thus, the mounting hardware member  112  is detached from the retainer  102 . Once the mounting hardware member  112  is detached from the retainer  102 , the opening  80  (see FIG. 6) can be uncovered and the battery can be inserted to or removed from the battery compartment without detaching the hook  111  of the lid  100  from the retainer  101 , due to the flexibility of the lid as shown in FIG. 8. If the hook  111  of the lid  110  is detached from the retainer  101  of the main unit  100 , the lid is separated from the main unit  100 .  
         [0064]    [0064]FIG. 10 shows a label affixed to the inner wall of the lid  110  which constitutes an inner wall of the battery compartment.  
         [0065]    This label can be seen when the lid  110  is viewed from the direction indicated by the arrow in FIG. 8.  
         [0066]    In the case of this cellular phone, only the opening  80  (see FIG. 6) of the battery compartment can be seen externally only when the lid  110  is removed. Thus, unlike conventional cellular phones, the label cannot be affixed to the battery mount in the battery compartment. Therefore, the label describing the specifications, the model number or the like is affixed to the inner wall of the lid  110 . This also holds true for the case of directly printing the specifications, the model number or the like instead of using such a label.  
         [0067]    [0067]FIG. 11 is a partial enlarged cross-sectional view of the cellular phone taken along the arrow X-X in FIG. 6.  
         [0068]    The flange  53  of the backside inner housing  50  is fitted into the channel  41  (see FIG. 2) of the backside outer housing  40 , and the circuit board  10  with the circuit component mounted thereon is disposed between the backside outer housing  40  and the backside inner housing  50 . On the backside outer housing  40 , the frontside outer housing  90  is disposed with their outer surfaces seamlessly connected.  
         [0069]    In the surface of the outermost edge of the backside outer housing  40  which is brought into contact with the edge of the frontside outer housing  90 , a groove  43  extending in the direction perpendicular to the sheet of FIG. 11 is formed. Similarly, in the surface of the outermost edge of the frontside outer housing  90  which is brought into contact with the edge of the backside outer housing  40 , a groove  93  extending in the direction perpendicular to the sheet of FIG. 11 is formed. The grooves  43  and  93  are filled with a waterproof filler  120  when assembling the cellular phone. Similarly, the channel  41  (see FIG. 2) of the backside outer housing  40 , into which the flange  53  of the backside inner housing  50  is fitted, is filled with the waterproof filler  120  when assembling the cellular phone.  
         [0070]    In addition, the circuit components on the circuit board  10  are coated with a waterproof filler  121  of a foam material, which is expandable in consideration of weight reduction.  
         [0071]    Since the joint between the housings and the space over the circuit board are filled with the fillers in this way, the waterproofing property is significantly improved.  
         [0072]    Although the cellular phone has been described herein as an example of the portable terminal device according to the present invention, the portable terminal device according to the present invention is not exclusively the cellular phone. The present invention may be applied to PHS (Personal Handyphone System), PDA (Personal Digital Assistants) or the like.