Abstract:
An electronic apparatus has a first housing having a first side portion and a second side portion having a width smaller than a width of the first side portion; a second housing having a third side portion having the same width as the first side portion, a fourth side portion having the same width as the second side portion, a face portion, and a glass assembly, the face portion being provided between the third side portion and the fourth side portion and including at least a portion having the same width as the width of the fourth side portion, the glass assembly being positioned in a rectangular region defined by the fourth side portion and virtual normal lines extending from end points of the fourth side portion to the third side portion; and a connecting portion connecting openable/closable the first housing with the second housing.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2007-324642 filed on Dec. 17, 2007, the entire contents of which are incorporated herein by reference. 
       BACKGROUND 
       [0002]    1. Field 
         [0003]    Recently, portable electronic apparatuses, such as a mobile phone and a laptop personal computer, which include a display device for displaying information, have come into widespread use. With regard to the portable electronic apparatuses, there has been a growing demand for reducing the size and weight of the apparatus and increasing the size of a display screen at the same time. To comply with such a demand, a general electronic apparatus includes a display device having a liquid crystal panel which is thin and light. In the electronic apparatus, a light source, a control substrate, etc., are disposed behind the liquid crystal panel so that the size of the display screen can be increased. Recently, a wide-screen electronic apparatus having a display screen that expands to areas near the sides of the housing has been suggested. 
         [0004]    The liquid crystal panel is obtained by enclosing a liquid crystal element between a plurality of glass plates, and is easily damaged by an impact from, for example, falling. In particular, in a wide-screen electronic apparatus in which the space between the housing and the liquid crystal panel is small, the impact from falling is directly transmitted to the liquid crystal panel from the housing. Therefore, such an electronic apparatus has a problem that impact resistance is lower than that of an electronic apparatus of the related art in which a sufficiently large space is provided between the housing and the liquid crystal panel. 
         [0005]    An example of an electronic apparatus of the related art includes a display housing that houses a display panel and a main housing that houses a circuit substrate and the like. The display housing is connected to the main housing such that the display housing can be opened and closed with respect to the main housing. This electronic apparatus includes protruding portions that protrude outward from four corners of the main housing. The protruding portions have hollow structures. 
       SUMMARY 
       [0006]    The disclosed electronic apparatus includes a first housing having a first side portion and a second side portion, the second side portion having a width smaller than a width of the first side portion and being parallel to the first side portion; a second housing having a third side portion, a fourth side portion, a face portion, and a glass assembly, the third side portion and the first side portion having the same width, the fourth side portion and the second side portion having the same width, the face portion being provided between the third side portion and the fourth side portion and including at least a portion having the same width as the width of the fourth side portion, the glass assembly being positioned in a rectangular region defined by the fourth side portion and virtual normal lines extending from end points of the fourth side portion to the third side portion; and a connecting portion connecting the first housing with the second housing such that the second housing is capable of being opened and closed with respect to the first housing. 
         [0007]    Additional aspects and/or advantages will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the invention. 
         [0008]    The above-described embodiments of the present invention are intended as examples, and all embodiments of the present invention are not limited to including the features described above. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    These and/or other aspects and advantages will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which: 
           [0010]      FIG. 1  is a perspective view of a personal computer which corresponds to an electronic apparatus according to a first embodiment; 
           [0011]      FIG. 2  is a diagram illustrating a side of a personal computer; 
           [0012]      FIG. 3  is a diagram illustrating a side of a personal computer opposite to the side shown in  FIG. 2 ; 
           [0013]      FIG. 4  is a diagram illustrating the internal structure of a personal computer; 
           [0014]      FIG. 5  is a diagram illustrating the state in which a display unit is closed on a main unit; 
           [0015]      FIG. 6  illustrates a sectional view of the display unit taken along a plane perpendicular to a longitudinal direction of a personal computer; 
           [0016]      FIG. 7  is a diagram illustrating the dimensions of a display housing and a main housing; 
           [0017]      FIG. 8  illustrates an enlarged view of an area around a protruding portion in the state in which a display housing is opened with respect to a main housing; 
           [0018]      FIG. 9  is a diagram illustrating the state in which a front cover of a display housing is removed; 
           [0019]      FIGS. 10A and 10B  are diagrams illustrating the relationship between the shape and visual impression of a main housing; 
           [0020]      FIG. 11  is a diagram illustrating the internal structure of a main unit; 
           [0021]      FIG. 12  illustrates a rear view of a personal computer in the state in which a display unit is closed on a main unit; 
           [0022]      FIG. 13  is a diagram illustrating the internal structure of a section around a cooling device in a main unit; 
           [0023]      FIG. 14  is a perspective view showing electronic components disposed under a metal plate shown in  FIG. 13 ; 
           [0024]      FIG. 15  is a diagram illustrating air passages; 
           [0025]      FIG. 16  is a perspective view showing a front side of a personal computer in the state in which a display unit is opened with respect to a main unit; 
           [0026]      FIG. 17  is a perspective view showing a rear side of a personal computer in the state in which a display unit is opened with respect to a main unit; 
           [0027]      FIG. 18  is an enlarged view of a section around the front edge of a main unit; 
           [0028]      FIG. 19  is a diagram illustrating a section around the front edge of a personal computer in the state in which a display unit is closed; 
           [0029]      FIG. 20  illustrates an enlarged view of a hinge part included in a hinge unit; 
           [0030]      FIG. 21  is a diagram illustrating the state of a hinge part while a display unit is being closed; 
           [0031]      FIG. 22  is a diagram illustrating the state of a hinge part when a display unit is closed on a main unit; 
           [0032]      FIG. 23  illustrates a sectional view of another display unit taken along a plane perpendicular to a longitudinal direction of a personal computer; and 
           [0033]      FIG. 24  illustrates a rear view of a display housing. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0034]    Reference will now be made in detail to the embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. The embodiments are described below to explain the present invention by referring to the figures. 
         [0035]    Embodiments corresponding to the above-described fundamental and applied aspects will be described with respect to the accompanying drawings. 
         [0036]      FIG. 1  is a perspective view of a personal computer  10  which corresponds to an electronic apparatus according to a first embodiment. 
         [0037]    The personal computer  10  includes a main unit  20  and a display unit  30 . The display unit  30  is connected to the main unit  20  with hinge units  40  such that the display unit  30  can be opened and closed with respect to the main unit  20 . The main unit  20  is an example of a main unit according to the present embodiment. The display unit  30  is an example of a display unit according to the present embodiment. The hinge units  40  are an example of a connecting portion according to the present embodiment.  FIG. 1  shows the personal computer  10 , viewed from the front, in a state in which the display unit  30  is opened. 
         [0038]    The main unit  20  performs various information processing operations. A main housing  28  accommodates therein a CPU and a hard disk device. The main housing  28  has a keyboard  21 , a trackpad  22 , a left click button  23 , and a right click button  24  on a top surface thereof. The main housing  28  also has a fingerprint sensor  25  and a medium slot  26  in a front section thereof. The fingerprint sensor  25  is used in a fingerprint authentication operation. The medium slot  26  receives a small recording medium. The main housing  28  is an example of a first housing according to the present embodiment. 
         [0039]    The display unit  30  displays the results of the information processing operations performed by the main unit  20 . A display housing  32  accommodates therein a thin liquid crystal panel, a control circuit for the liquid crystal panel, and a communication antenna. The display housing  32  includes a front cover  32 A and a back cover  32 B (see  FIG. 2 ). The liquid crystal panel is placed between the front cover  32 A and the back cover  32 B in a state such that a display screen  31  thereof faces the front. The display housing  32  is an example of a second housing according to the present embodiment. The display unit  30  is a wide-screen display device having various electronic components disposed behind the liquid crystal panel. 
         [0040]      FIG. 2  is a diagram illustrating a side of the personal computer  10 . 
         [0041]    A security slot  26   a  for a cable lock, a connector  26   b  for a power supply module, a connector  26   c  for an external monitor, a connector  26   d  for a LAN cable, USB connectors  26   e  and  26   f,  a connector  26   g  for an audio jack, a connector  26   h  for a microphone, and a connector  26   i  for a headphone are provided on one side of the main unit  20 . 
         [0042]      FIG. 3  is a diagram illustrating a side of the personal computer  10  opposite to the side shown in  FIG. 2 . 
         [0043]    An expansion card slot  27   a,  an optical disk slot  27   b,  a USB connector  27   c,  and a modem connector  27   d  are provided on the main unit  20  at the side opposite to the side shown in  FIG. 2 . The expansion card slot  27   a  receives an expansion card, such as a LAN card, for feature expansion. The optical disk slot  27   b  receives an optical disk, such as a CD or a DVD. 
         [0044]    The internal structure of the personal computer  10  will now be described. 
         [0045]      FIG. 4  is a diagram illustrating the internal structure of the personal computer  10 . 
         [0046]    Referring to  FIG. 4 , the personal computer  10  includes a CPU  101 , a main memory  102 , a hard disk drive  103 , an audio device  104 , an input interface  105 , an input device  106 , a display device  107 , the fingerprint sensor  25 , a small memory drive  109 , an optical disk drive  110 , a communication interface  111 , and an output interface  112 . The CPU  101  executes various programs. The main memory  102  is a memory device in which programs read from the hard disk drive  103  are expanded for execution by the CPU  101 . The hard disk drive  103  stores various programs and data. The audio device  104  has a microphone, speakers, etc., mounted therein. The input interface  105  receives data from an external device. The input device  106  includes the keyboard  21  and the trackpad  22 . The display device  107  displays information on the display screen  31 . The small memory drive  109  is used to access a small recording medium  61  attached thereto. The optical disk drive  110  is used to access a CD-ROM  62  or a DVD attached thereto. The communication interface  111  provides communication through an expansion card  63 . The output interface  112  outputs data to an external device. The above-mentioned elements are connected to each other through a bus  113 . 
         [0047]    The personal computer  10  according to the present embodiment incorporates various devices for reducing the size and weight of the apparatus, increasing the strength thereof, and improving the operability thereof. First, a device for increasing the strength of the personal computer  10  will now be described. 
         [0048]      FIG. 5  is a diagram illustrating the state in which the display unit  30  is closed on the main unit  20 . 
         [0049]    As shown in  FIG. 5 , the back cover  32 B of the display housing  32  has a projecting portion  210  obtained by bending a plate member at a central area of the personal computer  10  in the front-rear direction. The projecting portion  210  extends in the longitudinal direction of the personal computer  10  to both sides of the display housing  32 . The projecting portion  210  is an example of a projecting portion according to the present embodiment. 
         [0050]    The projecting portion  210  of the back cover  32 B serves to suppress deflection of the back cover  32 B. As a result, the strength of the display housing  32  is increased. Thus, according to the present embodiment, the display housing  32  is made of a thin, light material but has a high strength. Therefore, the weight of the apparatus can be reduced and the strength thereof can be increased at the same time. 
         [0051]      FIG. 6  illustrates a sectional view of the display unit  30  taken along a plane perpendicular to the longitudinal direction of the personal computer  10 . 
         [0052]    The display housing  32  includes the front cover  32 A and the back cover  32 B. The display housing  32  has a front face portion  201 , a back face portion  203 , and side-face portions  202 . The front face portion  201  covers a peripheral region of a front face of a liquid crystal panel  200  on which the display screen  31  is provided. The back face portion  203  covers a back face of the liquid crystal panel  200 . The side-face portions  202  connect the front face portion  201  and the back face portion  203  to each other. The liquid crystal panel  200  is an example of a glass assembly according to the present embodiment. The liquid crystal panel  200  is also an example of a display panel according to the present embodiment. The front face portion  201  is an example of a front face portion according to the present embodiment. The side-face portions  202  are an example of sidewall portions according to the present embodiment. The back face portion  203  is an example of a back face portion according to the present embodiment. 
         [0053]    The central area of the back face portion  203  is an area where the display housing  32  is most severely deflected when an impact from, for example, falling is applied. According to the present embodiment, the projecting portion  210  is formed at the central area so that the strength of the display housing  32  can be efficiently increased. In the personal computer  10 , the space between the liquid crystal panel  200  and the display housing  32  is set to be small in order to reduce the size of the apparatus. The projecting portion  210  of the display housing  32  is formed by a bending process, and accordingly a space S 1  is formed between a front face of the projecting portion  210  and the liquid crystal panel  200 . Therefore, even when a large impact is applied to the personal computer  10  and the display housing  32  is deflected, the projecting portion  210  is prevented from coming into contact with the liquid crystal panel  200 . Moreover, the impact can be absorbed by the space S 1  and the liquid crystal panel  200  can be prevented from being damaged. 
         [0054]    As described above, according to the present embodiment, the display housing  32  is made of a thin, light material but has a high strength. Therefore, the weight of the apparatus can be reduced and the strength thereof can be increased at the same time. 
         [0055]    Another device incorporated in the personal computer  10  to increase the strength thereof will now be described. 
         [0056]    The liquid crystal panel  200  having a small thickness is used as the display device  107  of the personal computer  10 . In the display device  107  of the personal computer  10 , the space between the display housing  32  and the liquid crystal panel  200  is reduced in order to reduce the size of the apparatus and increase the size of the display screen  31  at the same time. The liquid crystal panel is obtained by enclosing a liquid crystal element between a plurality of glass plates, and is easily damaged by an impact from, for example, falling. In addition, a wide-screen display device having a display screen that expands to areas near the side faces of a display housing has a problem that the impact from falling tends to be directly transmitted to the liquid crystal panel without being absorbed. The personal computer  10  according to the present embodiment incorporates a device for suppressing the occurrence of damage to the liquid crystal panel  200  due to an impact from falling. 
         [0057]      FIG. 7  is a diagram illustrating the dimensions of the display housing  32  and the main housing  28 . 
         [0058]    In  FIG. 7 , the external shape of the main housing  28  is shown by the dashed line. The main housing  28  has a rear portion  211 , to which the hinge units  40  are attached, and a front portion  212 . The rear portion  211  and the front portion  212  are parallel to each other, and the width W 1 ′ of the front portion  212  is smaller than the width W 1  of the rear portion  211 . Thus, the main housing  28  has a trapezoidal shape when viewed from above. The main housing  28  is an example of a first housing according to the present embodiment. The rear portion  211  is an example of a first side portion according to the present embodiment. The front portion  212  is an example of a second side portion according to the present embodiment. 
         [0059]    The display housing  32  has a rear portion  221 , to which the hinge units  40  are attached, and a front portion  222 . The width of the rear portion  221  is substantially equal to the width W 1  of the rear portion  211  of the main housing  28 , and the width W 2  of the front portion  222  is smaller than the width W 1  of the rear portion  221 . The width W 2  of the front portion  222  of the display housing  32  is set to be substantially equal to the width of a portion of the main housing  28  that corresponds to the front portion  222 . The length h 1  of the display housing  32  in the front-rear direction is smaller than the length h 2  of the main housing  28  in the front-rear direction. The display housing  32  is an example of a second housing according to the present embodiment. The front portion  222  is an example of a third side portion according to the present embodiment. The rear portion  221  is an example of a fourth side portion according to the present embodiment. An area between the front portion  222  and the rear portion  221  is an example of a face portion according to the present embodiment. 
         [0060]    The display housing  32  has a rectangular region  223  having the same width as the width W 2  of the front portion  222  and protruding portions  224  that protrude in the width direction at the rear end of the rectangular region  223 . The rectangular region  223  is an example of a rectangular region according to the present embodiment. An area in front of the front ends of the protruding portions  224  in the rectangular region  223  is an example of a first face portion according to the present embodiment. A total area including an area behind the front ends of the protruding portions  224  in the rectangular region  223  and areas of the protruding portions  224  correspond to an example of a second face portion according to the present embodiment. 
         [0061]      FIG. 8  illustrates an enlarged view of an area around one of the protruding portions  224  in a state in which the display housing  32  is opened with respect to the main housing  28 .  FIG. 9  is a diagram illustrating the state in which the front cover  32 A of the display housing  32  is removed. 
         [0062]    Referring to  FIG. 8 , the display housing  32  is connected to hinge units  40  at the side where the protruding portions  224 , which protrude in the width direction from the remaining portion, are provided. In addition, as shown in  FIG. 9 , the back cover  32 B of the display housing  32  has a rib  225  in each protruding portion  224  shown in  FIG. 7  such that each rib  225  is located adjacent to the rectangular region  223 . The liquid crystal panel  200  fits snugly between the ribs  225 . Since the ribs  225  are provided, the liquid crystal panel  200  can be easily placed in the display housing  32  and the display device  107  can be easily manufactured. The rib  225  is an example of a rib according to the present embodiment. The back cover  32 B provides a relatively large space S 2  between the display housing  32  and the liquid crystal panel  200  at each end of a side where the hinge units  40  are attached. The size of the spaces S 2  corresponds to the size of the protruding portions  224 . 
         [0063]    The center of gravity of the personal computer  10  is closer to the side where the hinge units  40  are provided than to the opposite side. Therefore, when the personal computer  10  falls, the personal computer  10  tends to fall with the hinge units  40  facing downward. According to the present embodiment, the impact from falling can be absorbed by the spaces S 2  provided between the display housing  32  and the liquid crystal panel  200 . Therefore, the damage to the liquid crystal panel  200  can be suppressed. In addition, according to the present embodiment, the personal computer  10  has a relatively large width only at the side where the hinge units  40  are provided. Thus, the increase in the size and weight of the apparatus is minimized. 
         [0064]    As described above, the personal computer  10  according to the present embodiment has the large spaces S 2  between the display housing  32  and the liquid crystal panel  200  only at the side where the hinge units  40  are provided. Therefore, the damage to the liquid crystal panel  200  can be suppressed without largely increasing the size of the apparatus. 
         [0065]    Next, a device for reducing the size of the personal computer  10  will be described. 
         [0066]    As described above with reference to  FIG. 7 , the main housing  28  of the personal computer  10  has a trapezoidal shape when viewed from above and the width of the rear portion  211  at which the hinge units  40  are attached is larger than that of the front portion  212 . 
         [0067]      FIGS. 10A and 10B  are diagrams illustrating the relationship between the shape and visual impression of the main housing  28 . 
         [0068]      FIG. 10A  shows a rectangular solid, and  FIG. 10B  shows a body with trapezoidal top and bottom faces having the same volume as that of the rectangular solid shown in  FIG. 10A . As is clear from  FIG. 10B , when the body having the trapezoidal top and bottom faces is placed such that short sides of the trapezoidal faces face front, the body appears as if it is smaller than the rectangular solid having the same volume shown in  FIG. 10A . 
         [0069]    The personal computer  10  according to the present embodiment has a trapezoidal body, and the hinge units  40  are attached to the trapezoidal body at the long side thereof. Therefore, the user operates the personal computer  10  while it is placed such that the short side of the trapezoidal body faces the user. Thus, according to the present embodiment, the personal computer  10  appears to the user as if it is smaller than an apparatus of the related art having a rectangular solid housing with the same volume. 
         [0070]      FIG. 11  is a diagram illustrating the internal structure of the main unit  20 . 
         [0071]    In  FIG. 11 , the external shape of the main housing  28  is shown by the dashed line, and the rectangular region having a width that is equal to the length of the short side of the trapezoidal main housing  28  is shown by the dot-dash line. As shown in FIG.  11 , the main housing  28  houses a power-source control circuit  331 , a display control circuit  332 , a communication control circuit  333 , an input-output control circuit (not shown in  FIG. 11 ), an audio circuit  335 , an expansion processing circuit (not shown in  FIG. 11 ), the optical disk drive  110 , and a data conversion circuit  337 . The main housing  28  also houses other electronic components such as a cooling mechanism  320  and a rechargeable battery  310 . The power-source control circuit  331  is connected to the connector  26   b  for the power supply module shown in  FIG. 2 . The display control circuit  332  is connected to the connector  26   c  for the external monitor. The communication control circuit  333  is connected to the connector  26   d  for the LAN cable. The input-output control circuit is connected to the USB connectors  26   e,    26   f,  and  27   c.  The audio circuit  335  is connected to the connector  26   g  for the audio jack, the connector  26   h  for the microphone, and the connector  26   i  for the headphone. The expansion processing circuit is connected to the expansion card slot  27   a  shown in  FIG. 3 . The optical disk drive  110  is connected to the optical disk slot  27   b.  The data conversion circuit  337  is connected to the modem connector  27   d.  The cooling mechanism  320  dissipates heat generated in the main housing  28 . The electronic components shown in  FIG. 11  are examples of processing circuits according to the present embodiment, and are also examples of electronic components according to the present embodiment. 
         [0072]    As shown in  FIG. 11 , a rear section of the main housing  28  where the hinge units  40  are attached is less dense compared to a front section thereof. Therefore, in the personal computer  10 , spaces for absorbing impact can be provided between the main housing  28  and the hinge units  40 . As a result, the impact resistance of the personal computer  10  can be increased. Some of the electronic components, such as the data conversion circuit  337  shown in  FIG. 11 , are disposed outside the rectangular region of the main housing  28  shown by the dot-dash line. The width of the main housing  28  at the front edge thereof can be reduced by placing the electronic components in the space provided in the rear section of the main housing  28 . As a result, according to the present embodiment, the personal computer  10  can be designed such that it appears to be small. 
         [0073]    As described above, according to the present embodiment, the main housing  28  is formed in a trapezoidal shape such that the width thereof in the front section is smaller than the width thereof in the rear section. Therefore, the apparatus appears to be small even when the volume of the main housing  28  is increased. 
         [0074]    A device for reducing the size of the cooling mechanism  320  shown in  FIG. 11  will now be described. 
         [0075]      FIG. 12  illustrates a rear view of the personal computer  10  in the state in which the display unit  30  is closed on the main unit  20 . 
         [0076]    The rechargeable battery  310  is fitted to a portion of the main unit  20  that defines the rear face of the personal computer  10 . Inlets  412  and outlets  411 , which form a part of the cooling mechanism  320 , are formed in the above-mentioned portion of the main unit  20 . The inlets  412  are disposed above the outlets  411 . Therefore, the risk that heat that remains in a region around the bottom of the personal computer  10  will be drawn in through the inlets  412  can be reduced. As a result, heat dissipation efficiency of the personal computer  10  can be maintained even if the personal computer  10  is continuously used. 
         [0077]      FIG. 13  is a diagram illustrating the internal structure of a section around the cooling mechanism  320  in the main unit  20 . 
         [0078]    As shown in  FIG. 13 , the cooling mechanism  320  includes a metal plate  431 , a heat pipe  432 , and a cooling fan  420 . The metal plate  431  is disposed above the electronic components, and heat generated by the electronic components is transferred to the metal plate  431 . The heat pipe  432  is attached to the metal plate  431 , and guides the heat transferred to the metal plate  431  to the outlets  411 . The cooling fan  420  discharges the heat guided through the heat pipe  432  together with air. The cooling fan  420  is an example of a cooling fan according to the present embodiment. 
         [0079]      FIG. 14  is a perspective view showing the electronic components disposed under the metal plate  431  shown in  FIG. 13 . 
         [0080]    The heat pipe  432  extends to the outlets  411  along the metal plate  431  through positions above a plurality of processing circuits  433  on which CPUs, controllers, etc., are mounted. 
         [0081]      FIG. 15  is a diagram illustrating air passages. 
         [0082]    Air that flows in through the inlets  412  is guided to the inside of the main housing  28 , as shown by arrow A. Heat generated by the processing circuits  433  shown in  FIG. 14  is transferred to the metal plate  431  and is guided along the heat pipe  432  to an area near the outlets  411 . The cooling fan  420  causes the air taken in through the inlets  412  to flow toward the outlets  411 . This air absorbs the heat transferred by the heat pipe  432 . The air, which has become warm by absorbing heat, is discharged through the outlets  411  as shown in by arrow B. The personal computer  10  according to the present embodiment has the inlets  412  and the outlets  411  in the same face of the main housing  28 . Therefore, the heat pipe  432 , the cooling fan  420 , etc., are placed in a small space in the personal computer  10  according to the present embodiment. As a result, the overall size of the apparatus is reduced. 
         [0083]      FIG. 16  is a perspective view showing the front side of the personal computer  10  in a state in which the display unit  30  is opened with respect to the main unit  20 .  FIG. 17  is a perspective view showing the rear side of the personal computer  10  in a state in which the display unit  30  is opened with respect to the main unit  20 . 
         [0084]    In a state in which the display unit  30  is opened, as shown in  FIG. 16 , the inlets  412  are positioned in front of the display unit  30 . In addition, in this state, as shown in  FIG. 17 , the outlets  411  are positioned behind the display unit  30 . In the case where the inlets and the outlets are provided in the same face of a housing, there is a risk that the warm air discharged through the outlets will be drawn into the housing through the inlets again. In such a case, the heat dissipation efficiency will be reduced. In the personal computer  10  according to the present embodiment, the outlets  412  and the inlets  411  are divided from each other by the display unit  30 . Therefore, the heat dissipation efficiency can be maintained. 
         [0085]    In addition, as shown in  FIG. 12 , the inlets  412  are exposed at the outer surface of the personal computer  10  even when the display unit  30  is in the closed state. Therefore, even when the display unit  30  is closed, air can be taken in through the inlets  412 . Thus, heat generated during the operation performed while the display unit  30  is closed can also be reliably dissipated to the outside of the main housing  28 . 
         [0086]    As described above, according to the personal computer  10  of the present embodiment, the size of the apparatus can be reduced and the heat dissipation efficiency can be increased at the same time. 
         [0087]    A device for improving the operability of the personal computer  10  will now be described. 
         [0088]    Laptop personal computers are not only operated while being placed on a desk or the like but may also be operated while being held with one hand by a user. The personal computer  10  according to the present embodiment has a structure for allowing the display unit  30  to be quickly and easily opened even when the personal computer  10  is operated while being held with one hand by a user. 
         [0089]      FIG. 18  is an enlarged view of a section around the front edge of the main unit  20 . 
         [0090]    The main unit  20  has the fingerprint sensor  25  and the medium slot  26  in a front section thereof. The fingerprint sensor  25  has a guide  25   a  for guiding a finger to the fingerprint sensor  25 . The main housing  28  is shaped such that portions where the medium slot  26  and the guide  25   a  are provided are recessed. The medium slot  26  and the guide  25   a  are examples of recesses according to the present embodiment. The fingerprint sensor  25  is an example of a fingerprint sensor according to the present embodiment. The guide  25   a  is an example of a guide used in a fingerprint reading operation according to the present embodiment. 
         [0091]    As shown in  FIG. 7 , the length h 2  of the main housing  28  in the front-rear direction is larger than the length h 1  of the display housing  32  in the front-rear direction. Therefore, the medium slot  26  and the guide  25   a  are exposed at the front surface of the personal computer  10  even when the display housing  32  is closed. The front portion  212  of the main housing  28  is also an example of a first front edge portion according to the present embodiment. The rear portion  211  is also an example of a first rear edge portion according to the present embodiment. The front portion  222  of the display housing  32  is also an example of a second front edge portion according to the present embodiment. The rear portion  221  is also an example of a second rear edge portion according to the present embodiment. 
         [0092]      FIG. 19  is a diagram illustrating a section around the front edge of the personal computer  10  in the state in which the display unit  30  is closed. 
         [0093]    As shown in  FIG. 19 , the main unit  20  protrudes forward from the display unit  30 . Therefore, the medium slot  26  and the guide  25   a  are exposed at the front surface of the personal computer  10 . The user can easily open the display unit  30  by inserting a finger into the medium slot  26  or the guide  25   a.  In addition, since the medium slot  26  is formed in the front section of the main housing  28 , the user can load a small recording medium while the display unit  30  is closed. In addition, since the fingerprint sensor  25  is disposed in the front section of the main housing  28 , the guide  25   a  having a sufficient length can be provided. As a result, the accuracy of fingerprint authentication can be improved. In the personal computer  10 , the medium slot  26  is formed so as to face not only forward but also upward in the personal computer  10 . Therefore, the user can visually check whether or not the small recording medium is loaded while, for example, operating the personal computer  10 . As described above, the medium slot  26  and the fingerprint sensor  25  are preferably provided in the front section of the main housing  28 . According to the personal computer  10  of the present embodiment, the operability is improved without forming an additional component, such as a pressing button, or forming an additional recess in the main housing  28 . Thus, the operability is improved without increasing the size or the manufacturing cost of the apparatus. 
         [0094]    Each hinge unit  40  of the personal computer  10  has a device for facilitating the operation of opening and closing the display unit  30 . 
         [0095]      FIG. 20  illustrates an enlarged view of a hinge part  500  included in one of the hinge units  40 . 
         [0096]    The hinge part  500  includes a main-body fixing portion  510 , a display fixing portion  520 , a rotating shaft  521 , a fixed cam portion  531 , a rotating cam portion  532 , and a disc spring  540 . The main-body fixing portion  510  is attached to the main unit  20 . The display fixing portion  520  is attached to the display unit  30 . The rotating shaft  521  is used for pivoting the display fixing portion  520  with respect to the main-body fixing portion  510 . The fixed cam portion  531  is fixed to the main-body fixing portion  510 . The rotating cam portion  532  rotates together with the rotating shaft  521 . The disc spring  540  presses the rotating cam portion  532  against the fixed cam portion  531 . The fixed cam portion  531  and the rotating cam portion  532  have tapered surfaces that can be fitted to each other. 
         [0097]      FIG. 20  shows a state in which the display unit  30  is opened with respect to the main unit  20  by 90 degrees. In the state in which the display unit  30  is opened with respect to the main unit  20  by 90 degrees, the tapered surfaces of the rotating cam portion  532  and the fixed cam portion  531  are not fitted to each other. In this state, rotation of the rotating cam portion  532  in a direction such that the display unit  30  is closed is locked. 
         [0098]      FIG. 21  is a diagram illustrating a state of the hinge part  500  while the display unit  30  is being closed.  FIG. 22  is a diagram illustrating the state of the hinge part  500  when the display unit  30  is closed on the main unit  20 . 
         [0099]    When the user starts to close the display unit  30 , the display fixing portion  520  starts to pivot. Accordingly, the rotating cam portion  532  rotates and the lock is released. When the display unit  30  reaches a given angle, the tapered surfaces of the rotating cam portion  532  and the fixed cam portion  531  slide along each other in such a direction that the tapered surfaces become fitted to each other. As a result, the display unit  30  is urged toward the main unit  20 . When the display unit  30  is closed on the main unit  20 , as shown in  FIG. 22 , the tapered surfaces of the rotating cam portion  532  and the fixed cam portion  532  become fitted to each other. 
         [0100]    According to the personal computer  10 , when the display unit  30  reaches a given angle, the display unit  30  is urged in such a direction that the display unit  30  becomes closed. Therefore, the user can easily close the display unit  30  with one hand. 
         [0101]    The electronic apparatus according to the first embodiment has been described above. Next, an electronic apparatus according to a second embodiment will now be described. In the electronic apparatus according to the second embodiment, the shape of the back cover that covers the back surface of the liquid crystal panel differs from that in the first embodiment. Other structures of the second embodiment are similar to those in the first embodiment. Therefore, elements similar to those in the first embodiment are denoted by the same reference numerals, and explanations thereof will thus be omitted. Only the structures different from those in the first embodiment will be described. 
         [0102]      FIG. 23  illustrates a sectional view of a display unit  30 ′ taken along a plane perpendicular to the longitudinal direction of the personal computer  10 . 
         [0103]    The display unit  30 ′ according to the present embodiment includes a projecting portion  210 ′ on a back face portion  203 ′ defined by a back cover  32 B′. In the display unit  30 ′ of the present embodiment, the projecting portion  210 ′ is placed on a plate member instead of being formed by bending the plate member. No space like the space S 1  shown in  FIG. 6  is provided between the liquid crystal panel  200  and the back face portion  203 ′. 
         [0104]    As described above, the projecting portion may be provided on the display housing by a method other than the bending process. If the bending process is applied, the space S 1  is formed between the liquid crystal panel  200  and the back face portion  203 , and the space S 1  provides advantages that the impact from falling can be absorbed and the projecting portion can be easily formed. 
         [0105]    The electronic apparatus according to the second embodiment has been described above. Next, an electronic apparatus according to a third embodiment will now be described. Also in the electronic apparatus according to the third embodiment, the shape of the back cover that covers the back surface of the liquid crystal panel differs from that in the first embodiment. Therefore, only the structures different from those in the first embodiment will be described. 
         [0106]      FIG. 24  illustrates a rear view of a display housing  32 _ 3 . 
         [0107]    The display housing  32 _ 3  according to the present embodiment includes not only a first projecting portion  210 _ 1  that extends in a longitudinal direction of the liquid crystal panel  200  but also a second projecting portion  210 _ 2  that extends perpendicular to the first projecting portion  210 _ 1  on the rear surface thereof. 
         [0108]    Since the second projecting portion  210 _ 2  that extends perpendicular to the first projecting portion  210 _ 1  is provided in addition to the first projecting portion  210 _ 1 , the strength of the display housing  32 _ 3  is further increased. 
         [0109]    In the above-described embodiments, a personal computer is explained as an example of an electronic apparatus. However, the electronic apparatus may also be other kinds of apparatuses such as a PDA, a game apparatus, a television set, and a mobile phone. 
         [0110]    In addition, in above-described embodiments, a liquid crystal panel is explained as an example of a display panel. However, the display panel is not limited to a liquid crystal panel, and may also be any type of display panel such as a plasma display, a field emission display, and an organic EL display. 
         [0111]    The many features and advantages of the embodiments are apparent from the detailed specification and, thus, it is intended by the appended claims to cover all such features and advantages of the embodiments that fall within the true spirit and scope thereof. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the inventive embodiments to the exact construction and operation illustrated and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope thereof.