Abstract:
An electronic apparatus includes a battery pack incorporating plural cells and a main section with an accommodating section where the battery pack is removably accommodated. The battery pack includes a groove section depressed in an external surface of battery pack toward space between the cells and extending in a predetermined direction. The accommodating section includes a projection section to be engaged in the groove section. The groove section is formed in a position on the external surface of the battery pack corresponding to a clearance between the plural cells, and the projection section of the main section is engaged in the groove section when the battery pack is attached. Therefore, without increasing the thickness of the entire electronic apparatus, there is realized a structure that determines the position of the battery pack with respect to the main section so that the battery pack can be prevented from being incorrectly attached.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to an electronic apparatus in which a battery pack is removably accommodated. 
         [0003]    2. Description of the Related Art 
         [0004]    In recent years, there has been widely used a portable electronic apparatus provided with a display device for displaying information, such as a portable phone and a laptop personal computer. For the portable electronic apparatus, in addition to enhancement of processing speed and expansion in functionality, downsizing and weight reduction are strongly demanded. Therefore, a display device with a thin and light liquid crystal panel has been employed, and electronic components incorporated in the electronic apparatus have been downsized and improved in terms of performance. 
         [0005]    Meanwhile, in many of portable electronic apparatus, the battery pack for supplying the power is removably mounted in a main housing. It is required to increase the storage capacity of the battery pack, because power consumption is increased due to the multi-functioning of the electronic apparatus, and also because the electronic apparatus is used without a power adapter more frequently. However, as the storage capacity of the battery pack becomes larger, the size of the battery pack becomes larger. In fact, the ratio of the battery pack to the entire apparatus in terms of size and weight is becoming large. On the other hand, without significant advances of the storage technique, it is difficult to greatly reduce the size and weight of the battery pack while realizing sufficient storage capacity. Therefore, at least reducing the size and weight of the mechanism for mounting the battery pack in the main housing has been required. 
         [0006]    For example, as disclosed in International Patent Application Publication No. 2007-086117 ( FIG. 3 ), as a method for removably mounting the battery pack in the main housing, the following way is generally carried out: a space surrounded with a frame in the main housing is formed, the battery pack is placed in the space, and a cover is disposed to cover the top of the battery pack, and so on. However, in order to reduce the size and weight of the electronic apparatus, it is preferable to expose a part of the battery pack on a surface of the electronic apparatus so that a part of the cover and the main housing required to cover the battery pack can be eliminated. 
         [0007]    In this regard, International Patent Application Publication No. 2006-117857 discloses a structure that a cutout is formed to extend from a flank to an underside of the main housing, and the battery pack is placed in the cutout. In this structure, it is conceivable that a cover or the like for covering the flank and the underside of the battery pack can be eliminated so as to efficiently reduce the size and weight of the apparatus, and also there is no need to attach and remove the cover when the battery pack is mounted. However, this structure has the following problems. If the battery pack is exposed on the surface of the electronic apparatus, since a supporting force by the main housing is reduced, backlash or slipping out of the battery pack is induced. In addition, since a wall that regulates the position of the battery pack is eliminated, it is difficult to mount the battery pack at a correct position in the main housing. 
       SUMMARY OF THE INVENTION 
       [0008]    The present invention has been made in view of the above circumstances and provides an electronic apparatus in which a battery pack can be correctly attached, while preventing an increase in size and weight of the apparatus. 
         [0009]    An electronic apparatus according to the present invention includes: 
         [0010]    a battery pack which incorporates a plurality of cells; and 
         [0011]    a main section which is provided with an accommodating section in which the battery pack is removably accommodated, 
         [0012]    wherein the battery pack includes a groove section on an external surface of the battery pack, the groove section being recessed in the external surface of the battery pack toward a point between the cells and extending in a predetermined direction, 
         [0013]    the accommodating section includes a projection section to be engaged in the groove section of the battery pack when the battery pack is attached. 
         [0014]    According to the above-described basic aspect of the electronic apparatus, there is provided the groove section depressed in the external surface of the battery pack at a position corresponding to the clearance formed between the adjacent cells incorporated in the battery pack, and the projection section of the main section is engaged in the groove section. Thus, it is possible to fix the position of the battery pack in the main section without increasing the thickness of the entire electronic apparatus, and to prevent the battery pack from being wrongly mounted. According to the basic aspect of the electronic apparatus, since the battery pack is prevented from moving in a direction crossing a direction in which the groove section is extended, even when the battery pack is exposed on the surface of the electronic apparatus, the backlash of the battery pack can be reduced. 
         [0015]    In the electronic apparatus according to the present invention, preferably, the plurality of cells are in the shape of a cylinder and disposed to be adjacent to each other in the battery pack so that central axes of the cylinders are parallel to each other, and 
         [0016]    the groove section is depressed toward a space formed between the adjacent cells. 
         [0017]    By thus arranging the plural cylindrical cells so that the central axes of the cells are in parallel to each other, space extending along the central axis is formed between the cells. By utilizing the space, it is possible to provide the sufficiently deep and long groove section in the battery pack without increasing the size of the apparatus. 
         [0018]    In the electronic apparatus according to the present invention, preferably, the battery pack has an external shape including a surface extending in a longitudinal direction, and 
         [0019]    the groove section is formed to extend in the longitudinal direction on the surface. 
         [0020]    According to this additional feature, since the long groove section can be provided in the battery pack, it is possible to increase an area where the battery pack and the main section are engaged with each other, thereby securely fixing the battery pack to the main section. 
         [0021]    In the electronic apparatus according to the present invention, preferably, at least one end of the groove section is positioned within the surface of the battery pack on which surface the groove section is formed. 
         [0022]    Generally, electronic components such as a connector and a board are contained in the battery pack in addition to the plural cells. Since one end of the groove section is within the surface of the battery pack, it is possible to dispose the electronic components around the end, thereby preventing the battery pack from being enlarged. 
         [0023]    In the electronic apparatus according to the present invention, preferably, the groove section extends such that at least one end of the groove section reaches a surface of the battery pack which surface is adjacent to the surface where the groove section is formed. 
         [0024]    Since the groove section is extended such that one end of thereof reaches an edge of the battery pack, it is possible to easily attach the battery pack to the main section while securely fixing the battery pack to the main section. 
         [0025]    In the electronic apparatus according to the present invention, preferably, the extension of the groove section is longer than that of the projection section. 
         [0026]    Since the groove section, which is longer than the projection section of the main section, is provided in the battery pack, it is possible to easily attach the battery pack to the main section. 
         [0027]    The electronic apparatus according to the present invention, preferably, the battery pack has an external shape that at least includes a first surface and a second surface adjacent to and larger than the first surface, 
         [0028]    the groove section is formed in the second surface of the battery pack, and 
         [0029]    the accommodating section includes an accommodating space defined at least by surfaces respectively facing the first surface and the second surface of the battery pack. 
         [0030]    According to the electronic apparatus with this additional feature, it is possible to expose the battery pack through at least two sides of the electronic apparatus while efficiently reducing the size and weight of the apparatus. Since the groove section is provided in the second side of the battery pack, whose area is relatively larger, it is possible to increase an area where the battery pack and the main section are engaged with each other, thereby securely fixing the battery pack to the main section. 
         [0031]    In the electronic apparatus according to the present invention, preferably, when the battery pack is accommodated in the accommodating section, at least one part of the battery pack is formed as a part of an external surface of the main section. 
         [0032]    Since the battery pack is provided as part of the external surface of the main section, it is possible to save a wall covering the battery pack, thereby reducing the size and weight of the electronic apparatus. 
         [0033]    In the electronic apparatus according to the present invention, preferably, the main section includes a front end section, a back end section, and a coupling section which couples a display section to the back end section such that the display section can be rotated, and 
         [0034]    the part of the battery pack forms an external surface of the back end section of the main section when the battery pack is accommodated in the accommodating section. 
         [0035]    It is preferable from the viewpoint of the operability to provide a fingerprint sensor for authenticating a person, which is widely mounted in the portable electronic apparatus, and a medium loading aperture, to which a small recording medium is loaded, in a front end surface of the electronic apparatus. For such a fingerprint sensor and a medium loading aperture, a groove-like guide and a loading aperture are formed by processing a wall of the housing. Therefore, in a case where the battery pack is exposed on the main section, it is necessary to provide the battery pack at a location which is separated from the fingerprint sensor and the medium loading aperture. As described above, by providing an accommodating section for containing the battery pack in the back-end side of the main section, it is possible to provide the fingerprint sensor and the medium loading aperture in the front-end side of the main section, thereby reducing the size and weight of the apparatus while maintaining its operability. 
         [0036]    In the electronic apparatus according to the present invention, preferably, the battery pack has an external shape including: 
         [0037]    a surface in which the groove section is formed and which extends in a longitudinal direction; and 
         [0038]    opposed lateral surfaces adjacent to the surface, a projection section being provided on one of the lateral surfaces and a biasing locking nail being provided on the other of the lateral surfaces, and 
         [0039]    the accommodating section includes concave sections in which the projection section and the biasing locking nail provided on the lateral surfaces of the battery pack are engaged when the battery pack is attached. 
         [0040]    According to this additional feature of the electronic apparatus, the battery pack can be securely fixed to the main section, and even when the battery pack is exposed on the surface of the electronic apparatus, it is possible to prevent the slipping off and the backlash of the battery pack. 
         [0041]    In the electronic apparatus according to the present invention, preferably, the battery pack includes a power output terminal on the lateral surface on which the projection section is provided, and 
         [0042]    the accommodating section includes a power input terminal to be connected to the power output terminal on the lateral surface of the battery pack when the battery pack is attached. 
         [0043]    According to this additional feature of the electronic apparatus, it is possible to easily connect a power output terminal of the battery pack and a power input terminal of the accommodating section, thereby securely supply the main section with the power of the battery pack. 
         [0044]    In the electronic apparatus according to the present invention, preferably, the lateral surfaces on which the projection section and the biasing locking nail are provided have an area smaller than the surface in which the groove section is formed. 
         [0045]    According to this additional feature of the electronic apparatus, since the long groove section is provided, it is possible to efficiently prevent the backlash of the battery pack. 
         [0046]    As described above, according to the electronic apparatus of the present invention, it is possible to prevent an increase in size and weight of the apparatus, and to correctly mount the battery pack. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0047]      FIG. 1  is an exterior appearance diagram of a personal computer which is a first embodiment of an electronic apparatus; 
           [0048]      FIG. 2  is a diagram illustrating a flank of the personal computer; 
           [0049]      FIG. 3  is a diagram illustrating a flank of the personal computer opposite to the flank shown in  FIG. 2 ; 
           [0050]      FIG. 4  is a back diagram of the personal computer; 
           [0051]      FIG. 5  is an underside diagram of the personal computer; 
           [0052]      FIG. 6  is an internal block diagram of the personal computer; 
           [0053]      FIG. 7  is a diagram illustrating the underside of the personal computer when a battery pack is removed; 
           [0054]      FIG. 8  is an underside diagram of a lower case while the battery pack is removed; 
           [0055]      FIG. 9  is a transparent diagram of the battery pack; 
           [0056]      FIG. 10  is a diagram illustrating a flank of the battery pack; 
           [0057]      FIG. 11  is a diagram illustrating a flank of the battery pack opposite to the flank shown in  FIG. 10 ; 
           [0058]      FIG. 12  is a diagram illustrating a keyboard and an operator board allocated in an upper surface of a partition plate; 
           [0059]      FIG. 13  is a diagram illustrating such a condition that the operator board is removed from the personal computer; 
           [0060]      FIG. 14  is a diagram illustrating such a condition that the operator board and the keyboard are removed from the personal computer; 
           [0061]      FIG. 15  is an enlarged diagram around a concave section; 
           [0062]      FIG. 16  is a diagram illustrating an underside, which faces the battery pack, of the partition plate; 
           [0063]      FIG. 17  is a diagram illustrating the upper surface of the partition plate while the battery pack is accommodated; 
           [0064]      FIG. 18  is a diagram illustrating a positional relation between keys and holes; 
           [0065]      FIG. 19  is a diagram illustrating an underside of the partition plate; 
           [0066]      FIG. 20  is an enlarged diagram around a flexible printed board; 
           [0067]      FIG. 21  is a diagram illustrating such a condition that a reinforcing plate of the flexible printed board is partially turned over; 
           [0068]      FIG. 22  is an upper surface diagram of the lower case; 
           [0069]      FIG. 23  is a diagram illustrating an underside, which faces a lower cover, of a hard disk to which the flexible printed board is connected; 
           [0070]      FIG. 24  is a diagram illustrating an upper surface of the hard disk; 
           [0071]      FIG. 25  is an enlarged diagram around a connector for the expansion; 
           [0072]      FIG. 26  is a diagram illustrating the underside, which faces a lower cover, of an auxiliary board; 
           [0073]      FIG. 27  is a diagram illustrating an upper surface of the auxiliary board; 
           [0074]      FIG. 28  is a diagram illustrating a motherboard while the auxiliary board is removed; 
           [0075]      FIG. 29  is an enlarged diagram around the connector for the expansion; 
           [0076]      FIG. 30  is an exterior appearance diagram of a port replicator; 
           [0077]      FIG. 31  is a diagram illustrating such a condition that the personal computer is connected to the port replicator; 
           [0078]      FIG. 32  is a flank diagram of a display section; 
           [0079]      FIG. 33  is a diagram illustrating a display panel attached to a back cover; 
           [0080]      FIG. 34  is an enlarged diagram of an engaging section in which the front cover and the back cover are engaged; 
           [0081]      FIG. 35  is a cross-sectional diagram of the display section in a first area in which a convex section is not provided in an upper stage section of the back cover; 
           [0082]      FIG. 36  is a cross-sectional diagram of the display section in a second area in which a projection section of the front cover is provided; and 
           [0083]      FIG. 37  is a cross-sectional diagram of the display section in a third area in which the convex section is provided in the upper stage section of the back cover. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0084]    Embodiments of the present invention will be described below by referring to the drawings. 
         [0085]      FIG. 1  is an exterior appearance diagram of a personal computer  10  which is a first embodiment of the electronic apparatus according to the present invention. 
         [0086]    The personal computer  10  is provided with a main unit  20  and a display unit  30 , the display unit  30  is openably and closably combined with the main unit  20  via a hinge section  40 . The main unit  20  corresponds to an example of the main section of the present invention, the display unit  30  corresponds to an example of the display section of the present invention, and the hinge section  40  corresponds to an example of the coupling section of the present invention.  FIG. 1  illustrates a diagram obtained by viewing, from the front, the personal computer  10  in which the display unit  30  is opened. 
         [0087]    The main unit  20  is used to execute various information processes, and a CPU, a hard disk, and the like are contained in a main housing  28 . The main housing  28  is configured with a high-strength metallic upper case  28 A and a high-strength metallic lower case  28 B. An upper surface of the upper case  28 A includes a keyboard in which plural keys  21  are arranged, a track pad  22 , a left click button  23 , a right click button  24 , and the like. Further, a fingerprint sensor  25  for authenticating a fingerprint by scanning a fingertip, and a medium loading aperture  26 , to which a small recording medium is loaded, are provided in the front area of the upper case  28 A. 
         [0088]    The display unit  30  is used to display a result of the information process executed by the main unit  20 , and a display housing  32  contains a thin-type liquid crystal panel, a controlling circuit for the liquid crystal panel, an antenna for the communication, and the like. The display housing  32  is configured with a front cover  32 A and a back cover  32 B (refer to  FIG. 2 ), and a display screen  31  of the liquid crystal panel is arranged in the front side, and the liquid crystal panel is sandwiched between the front cover  32 A and the back cover  32 B. Meanwhile, since various electronic components are allocated not in a flank of the liquid crystal panel, but in a back of the liquid crystal, the display unit  30  is a wide-type display device in which the display screen  31  is expanded up to a portion around the flanks of the display housing  32 . 
         [0089]      FIG. 2  is a diagram illustrating one flank of the personal computer  10 . 
         [0090]    The flank of the main unit  20  shown here includes a security slot  26   a  for a lock including a wire cable, a connector  26   b  for a power source module, a connector  26   c  for an external monitor, a connector  26   d  for a LAN cable, connectors  26   e  and  26   f  for a USB, a connector  26   g  for an audio jack, a connector  26   h  for a microphone, a connector  26   i  for a head phone, and the like. 
         [0091]      FIG. 3  is a diagram illustrating a flank of the personal computer  10  in an opposite side of  FIG. 2 . 
         [0092]    Another flank of the main unit  20 , which is opposite to the flank shown in  FIG. 2  includes an expansion card loading aperture  27   a  for loading an expansion card for expanding a function, such as a LAN card, an optical disk loading aperture  27   b  for loading a disk such as a CD and a DVD, a connector  27   c  for a USB, and a connector  27   d  for a modem. 
         [0093]      FIG. 4  is a back diagram of the personal computer  10 . 
         [0094]    The back of the personal computer  10  includes an air inlet  29   a  and an air outlet  29   b  configured in a cooling mechanism for radiating heat produced by electronic components. Since the air inlet  29   a  is provided above the air outlet  29   b , it is possible to reduce such a disadvantage that the heat, which is accumulated around a bottom of the personal computer  10 , is drawn from the air inlet  29   a , so that the heat-exhausting efficiency can be maintained even if the personal computer  10  is continuously used. A battery pack  50  for the power supply is engaged in the main unit  20 . The battery pack  50  corresponds to one example of the battery pack of the present invention. 
         [0095]      FIG. 5  is an underside diagram of the personal computer  10 . 
         [0096]    A connector for connecting to a peripheral device such as a printer, and a hard disk device for the expansion are mounted in the personal computer  10  of the present embodiment. Further, a port replicator, which is used to expand the function of the personal computer  10 , is connected to the personal computer  10  of the present embodiment. The battery pack  50 , which is also illustrated in  FIG. 4 , is exposed on an underside of the personal computer  10 , and a expansion connector  60 , which is to be coupled to a connector of the port replicator, is exposed from a through hole  61  provided in the main housing  28 . 
         [0097]    Next, an internal configuration of the personal computer  10  will be described. 
         [0098]      FIG. 6  is an internal configuration diagram of the personal computer  10 . 
         [0099]    As illustrated in  FIG. 6 , the personal computer  10  incorporates a CPU  101  for executing various programs, a main memory  102  in which a program, which is stored in a hard disk device  103 , is read and developed to be executed by the CPU  101 , the hard disk device  103  in which various programs, data, and the like are stored, an audio device  104  in which a microphone, a speaker, and the like are mounted, an input interface  105  for inputting data from an external device, an operator  106  including a keyboard and the track pad  22 , a display device  107  for displaying information on the display screen  31 , the fingerprint sensor  25  which is also illustrated in  FIG. 1 , a small memory drive  109  in which a small recording medium  61  is loaded and the loaded small recording medium  61  is accessed, an optical disk drive  110  in which a CD-ROM  62  or a DVD is loaded, and the loaded CD-ROM  62  and DVD are accessed, a communication interface  111  for communicating by using an expansion card  63 , an output interface  112  for outputting data to an external device, and the expansion connector  60 . These components are mutually connected through a bus  113 . 
         [0100]    Here, in the personal computer  10  of the present embodiment, multiple efforts are made to reduce the size and weight of the apparatus and also to improve the impact resistance. First, the efforts that have been made to reduce the size and weight of the main unit  20  will be described. 
         [0101]      FIG. 7  is a diagram illustrating the underside of the personal computer  10  when the battery pack  50  is removed. 
         [0102]    In the lower case  28 B of the main housing  28 , a cutout  28   a  is formed to extend from the flank to the underside of the personal computer  10 . In the state where the battery pack  50  is removed from the main housing  28 , a partition plate  75 , in which elements such as a keyboard having the plural keys  21  arranged on the top thereof are to be mounted, is exposed on the surface. Space formed by the cutout  28   a  corresponds to one example of the accommodating section of the present invention. 
         [0103]    The battery pack  50  includes a groove  51  which is extended in a longitudinal direction on a surface facing the main housing  28 , and a projection  52  at a flank. The groove  51  corresponds to one example of the “groove section of the battery pack” of the present invention. 
         [0104]    In the main housing  28 , a projection section  74 , which is to be engaged in the groove  51  of the battery pack  50 , is formed in the underside of the partition plate  75 . Further, provided at a sidewall of the cutout  28   a  are a power input terminal  71  for inputting the power from the battery pack  50 , and a concave section  72  in which the projection  52  of the battery pack  50  is to be engaged. At the opposite sidewall of the cutout  28   a , there are provided concave sections  73  in which nails  54  (refer to  FIG. 10 ) formed in the battery pack  50  are to be engaged. Since the projection section  74  of the main housing  28  is engaged in the groove  51  of the battery pack  50 , it is possible to easily position the battery pack  50  relative to the main housing  28 , to prevent incorrect mounting of the battery pack  50 , and to reduce the backlash of the battery pack  50 . The projection section  74  corresponds to one example of the “projection section engaged in the groove section of the battery pack” of the present invention. 
         [0105]      FIG. 8  is an underside diagram of the lower case  28 B while the battery pack  50  is removed. 
         [0106]    The cutout  28   a  is provided in the lower case  28 B, and since the battery pack  50  is engaged in this cutout  28   a , the underside and one side surface are exposed on the external surface of the personal computer  10 . Therefore, since a part of the battery pack  50  is exposed on the external surface of the personal computer  10 , it is possible to eliminate a part of the wall of the main housing  28  by the amount corresponding to the cutout  28   a , so that the size and weight of the apparatus can be reduced. 
         [0107]      FIG. 9  is a transparent diagram of the battery pack  50 . 
         [0108]    As illustrated in  FIG. 9 , plural cylindrical cells  53 , whose central axes are arranged together to extend along the direction of an arrow A, are contained in the battery pack  50 . The cell  53  corresponds to one example of the cell of the present invention. A clearance is formed between the adjacent cells  53  in the battery pack  50 , and the groove  51  aligned with the clearance is formed in the external surface of the battery pack  50 . In the present embodiment, since the groove  51  is formed by utilizing the clearance provided between the plural cells  53 , it is possible to provide the sufficiently deep and long groove  51  without increasing the size of the apparatus, and to securely prevent the backlash of the battery pack  50 . One edge side of the groove  51  is discontinuous in the surface of the battery pack  50 , and electronic components, such as a power output terminal  55  (refer to  FIG. 11 ) and a board, are contained in internal space P in the edge side. On the other hand, the other edge side of the groove  51  is extended up to the flank of the battery pack  50 , and the groove  51  is longer than the projection section  74  illustrated in  FIG. 7 . Since the groove  51  is extended up to the edge of the battery pack  50 , it is possible to easily mount the battery pack  50  to the main housing  28  and also, an area for engagement between the battery pack  50  and the main housing  28  is increased so that the backlash of the battery pack  50  can be surely suppressed. 
         [0109]      FIG. 10  is a diagram illustrating one flank of the battery pack  50 , and  FIG. 11  is a diagram illustrating the other flank of the battery pack  50  opposite to the flank shown in  FIG. 10 . 
         [0110]    As illustrated in  FIG. 10 , the nails  54 , which are to be engaged in the concave sections  73  illustrated in  FIG. 7 , are provided in the flank of the battery pack  50 . As illustrated in  FIG. 11 , in the flank of the battery pack  50  opposite to the flank shown in  FIG. 10 , there are provided the power output terminal  55  which is to be connected to the power input terminal  71  illustrated in  FIG. 7 , and outputs the power to the personal computer  10 , and the projection  52  inserted into the concave section  72  of the main housing  28 . The power output terminal  55  corresponds to one example of the power output terminal of the present invention, the projection  52  corresponds to one example of the “projection section provided in the battery pack” of the present invention, and the nail  54  corresponds to one example of the biasing locking nail of the present invention. The nail  54  and the projection  52  are provided in the flank, whose area is relatively small, of the battery pack  50 , and both sides of the battery pack  50  in a longitudinal direction are fixed to the main housing  28 , thereby, the battery pack  50  can be securely attached to the main housing  28 . 
         [0111]    As described above, according to the present embodiment, it is possible to prevent the size and the weight of the apparatus from being increased, to correctly mount the battery pack  50 , and to securely prevent the backlash and the slipping off of the loaded battery pack  50 . 
         [0112]    Next, the efforts made to reduce the size and weight of the apparatus in the upper surface of the partition plate  75  illustrated in  FIG. 7  will be described. 
         [0113]      FIG. 12  is a diagram illustrating the keyboard and an operator board to be disposed on the upper surface of the partition plate  75 . 
         [0114]    Disposed to be on the upper surface of the partition plate  75  are a keyboard  90  in which plural keys  21  are arranged, and an operator board  80  in which various buttons are arranged. The operator board  80  and the keyboard  90  correspond to one example of the first electronic components of the present invention, and the keyboard  90  also corresponds to one example of the keyboard of the present invention. 
         [0115]      FIG. 13  is a diagram illustrating such a condition that the operator board  80  is removed from the personal computer  10 , and  FIG. 14  is a diagram illustrating such a condition that the operator board  80  and the keyboard  90  are removed from the personal computer  10 . 
         [0116]    If the operator board  80  or the keyboard  90  is removed from the personal computer  10 , the upper surface of the partition plate  75  is partially exposed. On the upper surface of the partition plate  75 , a speaker  210  is disposed. The speaker  210  is connected to a controlling circuit (not-illustrated) through a cable  211 . The speaker  210  corresponds to one example of the second electronic component of the present invention, and corresponds to one example of the speaker of the present invention. The projection section  74  illustrated in  FIG. 7  is formed by denting a corresponding part of the upper surface of the partition plate  75 . This dented part is a concave section  74 ′ formed in the upper surface of the partition plate  75 . The concave section  74 ′ corresponds to one example of the “concave section for forming the internal space” of the present invention. 
         [0117]      FIG. 15  is an enlarged diagram around the concave section  74 ′. 
         [0118]    As illustrated in  FIG. 15 , the cable  211  connected to the speaker  210  is disposed in the concave section  74 ′, and the cable  211  is fixed by a tape  211 ′ to the concave section  74 ′. As illustrated in  FIG. 13  and  FIG. 14 , the cable  211  fixed to the concave section  74 ′ is to be covered with the operator board  80  and the keyboard  90 . As described above, since the concave section  74 ′ is utilized, which is obtained by hollowing the internal space of the projection section  74  for mounting the battery pack  50 , it is possible to secure the space for wiring the cable  211 . In addition, since the back of the projection section  74 , which is opposite to the side facing the battery pack  50 , is dented, and the cable  211  is wired in the dented portion (concave section  74 ′), it is possible to prevent such a disadvantage that the cable  211  is damaged due to attachment and detachment of the battery pack  50 . 
         [0119]    As described above, by utilizing the internal space of the projection section  74  for positioning the battery pack  50 , it is possible to secure the space for wiring the cable  211  while suppressing an in crease in size and weight of the apparatus. 
         [0120]    As illustrated in  FIG. 14 , plural elastic pieces  214  and plural holes  213  are provided in a part, in which the battery pack  50  is contained, of the partition plate  75 . Housing parts  215  formed between the plural holes  213  and the elastic pieces  214  are alternately provided. The elastic piece  214  corresponds to one example of the elastic piece of the present invention, and the housing part  215  corresponds to one example of the “part, which exists between the holes, of the housing” of the present invention. 
         [0121]      FIG. 16  is a diagram illustrating the underside, which faces the battery pack  50 , of the partition plate  75 , and  FIG. 17  is a diagram illustrating the upper surface of the partition plate  75  while the battery pack  50  is contained. 
         [0122]    As illustrated in  FIG. 16 , projections  214 ′ and  215 ′, which are extended as directing to the battery pack  50 , are provided in the elastic piece  214  and the housing part  215 , and an extension length of the projection  214 ′ of the elastic piece  214  is larger than that of the projection  215 ′ of the housing part  215 . The projection  214 ′ of the elastic piece  214  corresponds to one example of the first projection section of the present invention, and the projection  215 ′ of the housing part  215  corresponds to one example of the second projection section of the present invention. 
         [0123]    As illustrated in  FIG. 17 , the elastic piece  214  and the housing part  215  are provided with the projections  214 ′ and  215 ′ which are extended as directing from each part to the battery pack  50 , and the projections  214 ′ and  215 ′ are designed so that a predetermined clearance is provided between each projection and the battery pack  50  while the battery pack  50  is contained. That is, since the extension length of the projection  214 ′ of the elastic piece  214  is larger than that of the projection  215 ′ of the housing part  215 , the projections  214 ′ and  215 ′ are designed so that the clearance formed between the projection  214 ′ and the battery pack  50  is narrower than the clearance formed between the projection  215 ′ of the housing part  215  and the battery pack  50 . 
         [0124]    The size of an external shape of the battery pack  50  may be different from the specification because of the production variation. When the size of an external shape of the battery pack  50  is slightly larger than the specification because of such a production variation, in the present embodiment, only the projection  214 ′ of the elastic piece  214  contacts the battery pack  50 , and the battery pack  50  is appropriately held by absorbing a size error of the battery pack  50 . As described above, since the housing part  215  and the battery pack  50  do not contact each other, it is possible to prevent the battery pack  50  from being damaged and to prevent the personal computer  10  from failing due to the contact between the battery pack  50  and the housing part  215 . According to the present embodiment, since the battery pack  50  is biased by the projection  214 ′ of the elastic piece  214 , it is possible to securely suppress the backlash of the battery pack  50 . 
         [0125]    The keyboard  90  illustrated in  FIG. 12  is to be disposed above the elastic piece  214  and the housing part  215 . According to the present embodiment, since the size error of the battery pack  50  is absorbed only by the elastic piece  214  while the battery pack  50  does not contact the housing part  215 , a user, which operates the keyboard  90  mounted on the housing part  215 , is provided with the keying sense without the discomfort. The keyboard  90  functions to prevent the elastic piece  214  from being unlimitedly pushed and bent. 
         [0126]    When the size of an external shape of the battery pack  50  is further larger than the design specification, in the present embodiment, the battery pack  50  contacts the elastic piece  214  and the housing part  215 . The elastic piece  214  is extended from the partition plate  75 , and only one end is connected to the partition plate  75 , and on the other hand, both ends of the housing part  215  are connected to the partition plate  75 . Thus, if the width of the elastic piece  214  is the same as that of the housing part  215 , the elastic force generated by the elastic piece  214  is small. As illustrated in  FIG. 15 , in the present embodiment, a width W 1  of the elastic piece  214  is formed wider than a width W 2  of the housing part  215 . Thus, the elastic piece  214  and the housing part  215  are equally deformed in shape so that the elastic forces generated by both parts are equal to each other. As a result, the backlash of the battery pack  50  can be suppressed by the uniform force. Since the key  21  is supported from back by the elastic piece  214  and the housing part  215 , pressing each key  21  can provide the same click sense. 
         [0127]    As described above, in the present embodiment, when the size error of the battery pack  50  is small, only the projections  214 ′ of the elastic piece  214 , which can be changed in shape independently from the partition plate  75  (housing), contacts the battery pack  50 , and absorbs the size error of the battery pack  50 . Therefore, the discomfort that the user is likely to feel when operating the keyboard  90  is removed. When the size error of the battery pack  50  is large, since both of the projections  214 ′ of the elastic piece  214  and the projections  215 ′ of the housing part  215  contact the battery pack  50 , both of the projections  214 ′ of the elastic piece  214  and the projections  215 ′ of the housing part  215  function so as to counteract the battery pack  50  by means of the strong elastic forces, and absorb the size error. 
         [0128]    Here, as illustrated in  FIG. 14 , the plural octagonal holes  212  are provided at positions corresponding to some of the keys  21  of the keyboard  90 , of the partition plate  75 . The hole  212  corresponds to one example of “the hole of the housing” of the present invention. 
         [0129]      FIG. 18  is a diagram illustrating a positional relation between the key  21  and the hole  212 . 
         [0130]    As illustrated in  FIG. 18 , a shape of the plural keys  21  configured in the keyboard  90  is square, and the hole  212  is formed so that the upper and lower sides of the octagonal shape are aligned to the upper and lower sides of two adjacent keys  21 , and the left side of the one of the adjacent keys  21  and the right side of the other of the adjacent keys  21  pass through the central part of the octagonal shape. As a result, the center of the key  21  is positioned above a part of the partition plate  75  existing between the adjacent holes  212 , so that it is possible to reduce the weight of the partition plate  75  while maintaining the strength, and to prevent the keyboard  90  from being bent while maintaining the click sense that the user can feel when pressing the key  21 . 
         [0131]    As described above, according to the present embodiment, it is possible to reduce the weight of the apparatus while maintaining the strength for fixing the keyboard  90 . 
         [0132]    As illustrated in  FIG. 16 , in addition to the octagonal hole  212 , the partition plate  75  is provided with an octagonal frame, whose shape is the same as that of the hole  212 , in the underside facing the battery pack  50 . This octagonal frame makes the housing further stronger, and contributes to an increase in the strength for fixing the keyboard  90 . 
         [0133]    Next, various efforts made in the underside of the partition plate  75  illustrated in  FIG. 7  will be described. 
         [0134]    The battery pack  50  is mounted in a position close to the underside, which is opposite to the upper surface where the keyboard  90  is mounted, of the partition plate  75 , and various electronic components such as the CPU  101  and the hard disk device  103  are also mounted there. 
         [0135]      FIG. 19  is a diagram illustrating the underside of the partition plate  75 . 
         [0136]    The underside of the partition plate  75  is sectioned with ribs or the like to make spaces in which the electronic components are to be engaged. After the electronic components are fixed to the underside of the partition plate  75 , the lower case  28 B illustrated in  FIG. 8  is attached so that the electronic components are housed. The combination of the partition plate  75  and the upper case  28 A corresponds to one example of the housing frame of the present invention, and the lower case  28 B corresponds to one example of the housing cover of the present invention. A motherboard  300 A is screwed onto the partition plate  75 , and an auxiliary board  300 B is laid on the motherboard  300 A. Further, a cooling fan  320 , a hard disk  310  (corresponding to the hard disk device  103  illustrated in  FIG. 6 ), a controlling circuit  340 , an IC chip  330 , and the like are mounted on the motherboard  300 A. The expansion connector  60 , which is also illustrated in  FIG. 5 , projects from the auxiliary board  300 B. The hard disk  310  and the controlling circuit  340  are connected by a folded flexible printed board  350 , and the electronic components on the motherboard  300 A and the electronic components on the auxiliary board  300 B are also connected by a flexible printed board  430 . 
         [0137]      FIG. 20  is an enlarged diagram around the flexible printed board  350 . 
         [0138]    The flexible printed board  350  includes a first connector (not-illustrated) connected to a connector (not-illustrated) of the hard disk  310 , and further includes a wide section  351  which is bent toward the back of the personal computer  10  while the first connector is connected to the hard disk  310 . The flexible printed board  350  further includes: an extended section  352  which is first turned in a direction from the wide section  351  to a point for connection with the hard disk  310  and runs over the wide section  351  toward the controlling circuit  340 ; a second connector  353  connected to a connector of the controlling circuit  340 ; and a reinforcing plate  354  which extends from the wide section  351  in a direction intersecting the extended section  352 . The hard disk  310  and the flexible printed board  350  are contained in a box-like plastic case  311  in which a buffer material  312  is provided. The reinforcing plate  354  and the extended section  352  of the flexible printed board  350  are exposed outside the plastic case  311  through a cutout provided on a boundary line between the upper surface and the flank of the plastic case  311 , and are connected to the controlling circuit  340  and the like. The plastic case  311  will be described later in detail. The flexible printed board  350  corresponds to one example of the flexible board of the present invention, and the reinforcing plate  354  corresponds to one example of the reinforcing plate of the present invention. 
         [0139]      FIG. 21  is a diagram illustrating such a condition that the reinforcing plate  354  of the flexible printed board  350  is turned over. 
         [0140]    An additional IC chip  360 , which is selectively added only when a security function is added, is also mounted on the motherboard  300 A in addition to an IC chip  330  which is normally mounted on personal computers of the same model. A third connector  356 , which is connected to a connector  370  mounted on the motherboard  300 A, is provided in the reinforcing plate  354  of the flexible printed board  350 , and the reinforcing plate  354  is extended further longer than the position at which the third connector  356  is provided, and covers the additional IC chip  360 . Thus, without fixing the additional IC chip  360  by using a screw or solder, it is possible to prevent the additional IC chip  360  from dropping out. The connector  370  mounted on the motherboard  300 A corresponds to one example of the first connection section of the present invention, the third connector  356  of the flexible printed board  350  corresponds to one example of the second connection section of the present invention, and the additional IC chip  360  corresponds to one example of the “component selectively mounted on the board” of the present invention. 
         [0141]      FIG. 22  is an upper surface diagram of the lower case  28 B illustrated in  FIG. 8 . 
         [0142]    Disposed on the upper surface of the lower case  28 B are a first projection  381  and a second projection  382 . The second projection  382  is provided at a position that corresponds to the connector  370  of the motherboard  300 A when the lower case  28 B is attached to the upper case  28 A, and the first projection  381  is provided at a position that corresponds to a position where the additional IC chip  360  is mounted when the lower case  28 B is attached to the upper case  28 A. Each of the first projection  381  and the second projection  382  corresponds to one example of “the projection section which abuts the reinforcing plate” of the present invention. 
         [0143]    The motherboard  300 A and the auxiliary board  300 B illustrated in  FIG. 19  are pressed by screws or the like from the upper surface of the lower case  28 B, and various IC chips  330  are soldered to the motherboard  300 A and the auxiliary board  300 B. When an optional function is added, the additional IC chip  360  is connected to the motherboard  300 A, and the lower case  28 B is mounted while being covered by the reinforcing plate  354  of the flexible printed board  350 . As a result, the first projection  381  of the lower case  28 B presses, via the reinforcing plate  354 , the connector  370  of the motherboard  300 A and the third connector  356  of the flexible printed board  350 , and the second projection  382  of the lower case  28 B presses, via the reinforcing plate  354 , the additional IC chip  360 . As described above, according to the present embodiment, only by attaching the lower case  28 B, it is possible to easily and securely prevent the additional IC chip  360  from dropping out. 
         [0144]    As also illustrated in  FIG. 21 , the hard disk  310  is contained in the box-like plastic case  311  in which the buffer material  312  is provided. The plastic case  311  corresponds to one example of the box-like case of the present invention. 
         [0145]      FIG. 23  is a diagram illustrating the underside, which faces the lower case  28 B, of the hard disk  310  to which the flexible printed board  350  is connected, and  FIG. 24  is a diagram illustrating the upper surface of the hard disk  310 . 
         [0146]    As described above, the folded flexible printed board  350  is connected to the hard disk  310 . In the flexible printed board  350 , the wide section  351  spreads on the side, which faces the lower case  28 B, of the hard disk  310 , the extended section  352  is folded to run over the wide section  351 , and the reinforcing plate  354  projects from the wide section  351  in a direction crossing the extended section  352 . The wide section  351  corresponds to one example of the first section of the present invention, the extended section  352  corresponds to one example of the second section of the present invention, and the reinforcing plate  354  corresponds to one example of the third section of the present invention. 
         [0147]    The plural buffer materials  312  and  314  are provided on the sides, which face the underside and the upper surface of the hard disk  310  respectively, of the plastic case  311 . In the underside, a cutout  313 , which is used to pull up, is provided from one flank  401 , in which the connector of the hard disk  310  is provided, to the other flank  402 , which is an opposite side of the flank  401 . Since the cutout  313  is provided, it is possible to easily contain the flexible printed board  350  in the plastic case  311 . The buffer material  312  contacting the back cover  32 B corresponds to one example of the second buffer material of the present invention, and the buffer material  314  facing the partition plate  75  corresponds to one example of the first buffer material of the present invention. 
         [0148]    According to the present embodiment, since the flexible printed board  350  connected to the hard disk  310  lies while being folded between the hard disk  310  and the back cover  32 B, when the personal computer  10  falls, or the like, the flexible printed board  350  absorbs the impact as a cushion. Thus, it is possible to reduce the impact applied to the hard disk  310  without providing a large amount of buffer material, and to prevent troubles such as failure and breakage of the hard disk  310 . 
         [0149]    Next, the expansion connector  60  illustrated in  FIG. 19  will be described in detail. 
         [0150]    As described in  FIG. 19 , the auxiliary board  300 B is laid on the motherboard  300 A, the expansion connector  60  projects from the auxiliary board  300 B, and as illustrated in  FIG. 5 , the expansion connector  60  is exposed from the through hole  61  of the main housing  28 . 
         [0151]      FIG. 25  is an enlarged diagram around the expansion connector  60 . 
         [0152]    As shown in  FIG. 25 , there is a difference in height between the motherboard  300 A and the auxiliary board  300 B, and the auxiliary board  300 B is disposed closer to the lower case  28 B as compared with the motherboard  300 A. 
         [0153]      FIG. 26  is a diagram illustrating the underside, which faces the lower case  28 B, of the auxiliary board  300 B, and  FIG. 27  is a diagram illustrating the upper surface of the auxiliary board  300 B. 
         [0154]    The expansion connector  60  is mounted on the undersurface of the auxiliary board  300 B, and a coupling connector  410 , which is overlapped with the expansion connector  60  across the auxiliary board  300 B, is mounted on the upper surface of the auxiliary board  300 B. The expansion connector  60  corresponds to one example of the third connector of the present invention, the coupling connector  410  corresponds to one example of the second connector of the present invention, and the auxiliary board  300 B corresponds to one example of the second board of the present invention. 
         [0155]      FIG. 28  is a diagram illustrating the motherboard  300 A while the auxiliary board  300 B is removed. 
         [0156]    A main-unit-side connector  420  is mounted in the underside, which faces the lower case  28 B, of the motherboard  300 A. To the main-unit-side connector  420 , the coupling connector  410  illustrated in  FIG. 27  of the auxiliary board  300 B is to be connected. The main-unit-side connector  420  corresponds to one example of the first connector of the present invention, and the motherboard  300 A corresponds to one example of the first board of the present invention. 
         [0157]    When the auxiliary board  300 B is connected to the motherboard  300 A, the coupling connector  410  of the auxiliary board  300 B is coupled with the main-unit-side connector  420  of the motherboard  300 A, the main-unit-side connector  420 , the auxiliary board  300 B, and the expansion connector  60  are stacked and combined. Therefore, there is no need to particularly provide a long connector which can directly connect the motherboard  300 A with the port replicator, and the port replicator can be securely connected with suppressed manufacturing costs. 
         [0158]      FIG. 29  is an enlarged diagram around the expansion connector  60 . 
         [0159]    As illustrated in  FIG. 29 , in addition to the main-unit-side connector  420 , the auxiliary board  300 B, and the expansion connector  60 , connectors  431  and  432 , which mutually connect the electronic components mounted on each board by using the flexible printed board  430 , are provided on the motherboard  300 A and the auxiliary board  300 B. The flexible printed board  430  corresponds to one example of the signal line of the present invention. 
         [0160]    Since the flexible printed board  430  connects the electronic components mounted on each of the motherboard  300 A and the auxiliary board  300 B, it is possible to efficiently utilize the space formed by the difference in height, and to downsize the apparatus. 
         [0161]      FIG. 30  is an exterior appearance diagram of a port replicator  500 , and  FIG. 31  is a diagram illustrating such a condition that the personal computer  10  is mounted to the port replicator  500 . 
         [0162]    As illustrated in  FIG. 30 , a connector  510 , which is to be combined with the expansion connector  60  of the personal computer  10  when the personal computer  10  is mounted, projects from the upper surface of the port replicator  500 . The connector  510  corresponds to one example of the external device side connector of the present invention. When the personal computer  10  is mounted or demounted on or from the port replicator  500 , the expansion connector  60  is pushed or pulled with the strong force. However, according to the present embodiment, since the main-unit-side connector  420 , the auxiliary board  300 B, and the expansion connector  60  are stacked and combined, it is possible to increase the strength, and it is also possible to prevent the backlash and the damage of the expansion connector  60  because the personal computer  10  is repeatedly mounted or demounted. 
         [0163]    Next, efforts made to reduce the size and weight of the display unit  30  will be described. 
         [0164]      FIG. 32  is a flank diagram of the display unit  30 . 
         [0165]    In the display unit  30 , a liquid crystal panel  610  is contained between the front cover  32 A and the back cover  32 B. The front cover  32 A corresponds to one example of the front cover of the present invention, the back cover  32 B corresponds to one example of the back cover of the present invention, and the liquid crystal panel  610  corresponds to one example of the display panel of the present invention. 
         [0166]    The front cover  32 A is composed of: a front frame section  610 A which covers a marginal edge in a front side of the liquid crystal panel  610 ; and a front rib section  610 B which goes around a flank of the liquid crystal panel  610 . Plural projections  630  which are separated from each other are formed on the bottom edge, which faces the back cover  32 B, of the front rib section  610 B. The front frame section  610 A corresponds to one example of the front frame of the present invention, the front rib section  610 B corresponds to one example of the front rib of the present invention, and the protrusion  630  corresponds to one example of the “projection section inserted into the hollow section” of the present invention. In this example, the front rib section  610 B corresponds to one example of the second rib of the present invention, and the bottom end surface of the front cover  32 A corresponds to one example of the second end surface of the present invention. 
         [0167]    Since the back cover  32 B and the front rib section  610 B are engaged with each other, the back cover  32 B covers the flank and the back of the liquid crystal panel  610 . In the front end surface of the back cover  32 B, which surface faces the front rib section  610 B, the inner part (upper stage part  640 ) close to the liquid crystal panel  610  is formed higher than the outer part (lower stage part). A hollow  650 , which is lower than the outer part and in which the protrusion  630  of the front rib section  610 B is to be inserted, is formed in the upper stage part  640 . The hollow  650  corresponds to one example of the hollow section of the present invention. In this example, the part, which covers a flank of the liquid crystal panel  610 , of the back cover  32 B corresponds to one example of the first rib of the present invention, and the front end surface of the back cover  32 B corresponds to one example of the first end surface of the present invention. 
         [0168]      FIG. 33  is a diagram illustrating the liquid crystal panel  610  attached to the back cover  32 B. 
         [0169]    As illustrated in  FIG. 33 , the plural hollows  650  of the back cover  32 B are separately provided along a flank of the back cover  32 B, and are open on both of the front end surface and the inner surface. 
         [0170]      FIG. 34  is an enlarged diagram of an engaging section in which the front cover  32 A and the back cover  32 B are engaged. 
         [0171]    A linear projection  631  is formed in a central part of the protrusion  630 , which is also illustrated in  FIG. 32 , of the front cover  32 A, and absorbs a size error of the hollows  650 . A frame part  660  of the front cover  32 A contacts the lower stage part which is formed in the front end surface of the back cover  32 B, and the upper stage part  640  of the back cover  32 B is placed inside the frame part  660 . A convex section  641 , which projects outward, is formed on the upper stage part  640 , and is engaged with a convex section  661  formed on the frame part  660  (refer to  FIG. 37 ). The protrusion  630  of the front cover  32 A is inserted into the hollow  650  of the back cover  32 B. As illustrated in  FIG. 34 , since a width W 3  of the hollow  650  is narrower than a width W 4  of the upper stage part  640 , the strength of the display housing  32  can be maintained. 
         [0172]      FIG. 35  is a cross-sectional diagram of the display unit  30  in a first area in which the convex section  641  is not provided in the upper stage part  640  of the back cover  32 B. 
         [0173]    In the first area illustrated in  FIG. 35 , the frame part  660  of the front cover  32 A contacts the lower stage part of the back cover  32 B, and the upper stage part  640  of the back cover  32 B is placed inside the frame part  660  of the front cover  32 A while overlapping with the frame part  660 . 
         [0174]      FIG. 36  is a cross-sectional diagram of the display unit  30  in a second area in which the protrusion  630  of the front cover  32 A is provided. 
         [0175]    In the second area illustrated in  FIG. 36 , the frame part  660  of the front cover  32 A contacts the lower stage part of the back cover  32 B, and the hollow  650  deeper than the lower stage part is formed inside the back cover  32 B. The protrusion  630  is disposed inside the frame part  660  of the front cover  32 A when being inserted into the hollow  650 . Therefore, the protrusion  630  of the front cover  32 A is inserted into the hollow  650  of the back cover  32 B while overlapping with the back cover  32 B. 
         [0176]    As described above, according to the present embodiment, in the first area illustrated in  FIG. 35 , the front cover  32 A and the back cover  32 B are overlapped with each other such that part of the back cover  32 B is disposed inside, whereas in the second area illustrated in  FIG. 36 , the front cover  32 A and the back cover  32 B are overlapped with each other such that part of the front cover  32 A is disposed inside. Thus, since the front cover  32 A and the back cover  32 B regulate each other while moving in the overlapping direction, it is possible to fix the front cover  32 A and the back cover  32 B without using an additional component such as a rib, and to reduce the size and weight of the apparatus while increasing the size of the display screen. 
         [0177]      FIG. 37  is a cross-sectional diagram of the display unit  30  in a third area in which the convex section  641  is provided in the upper stage part  640  of the back cover  32 B. 
         [0178]    As illustrated in  FIG. 37 , in the third area, as compared with the first area illustrated in  FIG. 35 , the convex section  641  that projects outward is provided in the upper stage part  640  of the back cover  32 B, and the convex section  661  that projects inward is provided in the frame part  660  of the front cover  32 A. Since such convex sections  641  and  661  are engaged with each other, it is possible to securely fix the front cover  32 A and the back cover  32 B. The convex section  641  of the back cover  32 B corresponds to one example of the engaging projection section of the present invention, and the convex section  661  of the front cover  32 A corresponds to one example of the engaged projection section of the present invention. 
         [0179]    As described above, according to the present embodiment, it is possible to narrow the width of a part, which surrounds the edge of the liquid crystal panel  610 , of the display housing  32 , thereby reducing the size and weight of the apparatus while increasing the size of the display screen. 
         [0180]    Here, in the above description, while the personal computer is used as an example of the electronic apparatus described in “SUMMARY OF THE INVENTION”, this electronic apparatus may be a notebook type of computer, a PDA, a game machine, a television, a portable phone, and the like. 
         [0181]    In the above description, the liquid crystal panel is used as an example of the display panel of the present invention, but the display panel of the present invention is not limited to the liquid crystal panel and may be any type of display panel such as a plasma display, a field emission display, an organic EL display, and the like. 
         [0182]    In the above description, although the hole, which is formed in the partition plate supporting the keyboard at a position corresponding to each of plural keys is octagonal, the hole may be, for example, circular. However, since the shape of a key is generally square in the keyboard provided in a personal computer, the octagonal hole is made in the partition plate and four of the eight sides of the hole are parallel to the four sides of the square key in the above-described embodiment and thus, it is possible to efficiently reduce the weight of the housing while maintaining the strength. 
         [0183]    In the above description, while there is used such an example that the flexible printed board is folded so that the hard disk can be prevented from being damaged, the first electronic component of the present invention may be a mechanical driving electronic component other than the hard disk, and for example, may be also a drive for a recording medium, and the like. 
         [0184]    In the above description, there is used such an example that the personal computer is connected to the port replicator. However, the function expanding apparatus of the present invention is not limited to the port replicator and may be an expansion station or a docking station that incorporates an optical disk drive, an expansion battery, and the like, and also may be an external adaptor for adding a communication function to the personal computer.