Abstract:
An apparatus includes a heat generating component; a heat radiating member that absorbs heat from the heat generating component and radiates heat; a fan that sends air toward the heat radiating member; a housing incorporating the heat generating component, the heat radiating member and the fan, and including a first opening that discharges air warmed up by the heat radiating member to an outside and a second opening that exposes an air inlet portion of the heat radiating member in which air from the fan enters; and a cover member that is detachably attached to the housing and covers the second opening.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit under 35 U.S.C. Section 119 of Japanese Patent Application No. 2006-346447, filed Dec. 22, 2006, and Japanese Patent Application No. 2006-222127, filed Aug. 16, 2006, which are hereby incorporated by reference in their entireties into this application. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an apparatus that has a built-in heat generating component, and to a data processing apparatus that has a built-in heat generating component and performs data processing. 
     2. Description of the Related Art 
     There are various types of apparatuses having a built-in component that generates heat when in use. Although some of them perform their intended function by generating heat, it is not desirable for the other apparatuses to generate heat by the built-in component. Thus, some techniques are devised to suppress rise in temperature of the apparatus due to heat generated by the built-in heat generating component. For example, Japanese Patent Application Publication No. 2002-217343 and Japanese Utility Model Publication No. 5-55591 disclose that a heat sink and a heat radiating member is used to radiate heat generated by a power transistor, while Japanese Patent Application Publication No. 2006-135073 discloses the structure that heat generated by a voice coil motor is conducted to a housing of a hard disc drive via heat radiating fins. 
     Additionally, another typical technique for suppressing heat is that a fan is provided in an apparatus to generate airflow, thereby cooling down a heat generating component. For example, Japanese Patent Application Publication No. 2005-321287 discloses the structure in which heat generated by a heat generating component is conducted via a heat pipe to heat radiating fins. Airflow that is generated by rotation of a fan absorbs heat while passing through between the heat radiating fins and then warmed air is discharged from the apparatus. 
     Use of such a structure is widespread as it is effective in suppressing rise in temperature of a heat-generating component. 
     However, such a structure entails the following problems. Firstly, heat radiating fins are likely to be covered in dust at the inlet thereof, which blocks air flow and thus deteriorates cooling capacity thereof, resulting in rise in temperature of a heat-generating component. Consequently, this may disable normal operation of the heat-generating component and shorten the life of its peripheral components as well as the heat component. Secondly, even without such abnormal conditions, if an apparatus is configured to adjust cooling capacity by changing the speed of a fan, the increased speed of the fan for securing cooling capacity will make noise of the fan larger. 
     Meanwhile, Japanese Patent Application Publication No. 2005-321287 deals with the first problem, by providing a tilted portion formed at the inlet of the heat radiating fins, aiming at moving dust by causing dust to be carried by air flow from a fan along the tilted portion and discharged from the apparatus. 
     Although provision of the tilted portion may delay the time for the dust to be accumulated, this does not substantially solve the problem. 
     Additionally, a heat radiating member and a fan are typically disposed inside an apparatus while only an outlet, from which air passed through the heat radiating member is discharged, is exposed to be seen from outside. On the other hand, dust is accumulated at the inlet of the heat radiating member and thus, in order to remove accumulated dust, the apparatus must be disassembled, which is rather difficult to perform. 
     SUMMARY OF THE INVENTION 
     The present invention has been made in view of the above circumstances, and provides an apparatus and a data processing apparatus that have a structure enabling easy recovery of coolability downgraded due to accumulated dust therein. 
     An apparatus according to the invention having: 
     a heat generating component; 
     a heat radiating member that absorbs heat from the heat generating component and radiates heat; 
     a fan that sends air toward the heat radiating member; 
     a housing incorporating the heat generating component, the heat radiating member and the fan, and including a first opening that discharges air warmed up by the heat radiating member to an outside and a second opening that exposes an air inlet portion of the heat radiating member in which air from the fan enters; and 
     a cover member that is detachably attached to the housing and covers the second opening. 
     As the apparatus of the invention is provided with the second opening that exposes the air inlet portion in which air from the fan enters and the cover member that is detachably attached to the housing and covers the second opening, cleaning of the air inlet portion is made easy, which enables easy recovery of coolability downgraded due to accumulated dust in the air inlet portion. 
     Preferably, in the apparatus according to the invention, the cover member is manually detached. 
     The above feature facilitates east cleaning of the air inlet portion. 
     More preferably, in the apparatus according to the invention, the first opening is formed in one side of the housing and the second opening is formed in a top face of the housing. 
     The first opening, from which air warmed up by the heat radiating member is discharged, is desirably formed in a side of the housing (more preferably a back-facing face of the housing) so that it may not interfere with the operation of the apparatus. Meanwhile, the second opening is desirably formed in the top face so as to be easily cleaned. 
     Further preferably, in the apparatus according to the invention, the housing has an opening for holding the cover member, the opening being formed at a position covered by the cover member, and the cover member has a projection that engages in the opening so as to be held therein, the projection being formed on a face of the cover member facing the housing when attached to the housing. 
     The above structure enables easy engagement and disengagement of the cover member with and from the housing. 
     Also preferably, in the apparatus according to the invention, the housing has a recess that has space for a finger or a fingernail to hold the cover member attached to the housing. 
     Forming of such a recess facilitates easy detachment of the cover member. 
     Preferably, in the apparatus of this invention, the cover member is formed so as to be wider than the second opening of the housing such that the cover member overlaps an edge portion that defines the second opening. 
     If the cover member is wider enough to overlap the edge portion of the second opening, it is possible to prevent air from the fan from leaking out through a gap between the second opening and the cover member. It is also possible to prevent entrance of foreign matter into the apparatus through the cover member and the second opening. 
     Further preferably, in the apparatus according to this invention, an air guide wall is provided at each of both ends of the air inlet portion, which guides air from the fan to the air inlet portion and prevents the air from leaking out off the heat radiating member, 
     wherein the edge portion defining the second opening of the housing extends to a position over the air guide walls such that the second opening is restrictedly formed within an area sandwiched between the air guide walls at both ends of the air inlet portion. 
     As the second opening is restrictedly formed within an area sandwiched between the air guide walls, it is possible to prevent air from the fan from leaking out into the apparatus through a gap between the cover member and the air guide walls, which enhances coolability. In addition, it is possible to prevent entrance of the dust accompanying air from the fan into the apparatus. 
     According to another aspect of the invention, a data processing apparatus that processes data including: 
     a heat generating component; 
     a heat radiating member that absorbs heat from the heat generating component and radiates heat; 
     a fan that sends air toward the heat radiating member; 
     a housing incorporating the heat generating component, the heat radiating member and the fan, and including a keyboard for input operation arranged on a top face thereof, a first opening that discharges air warmed up by the heat radiating member to outside, the first opening formed in one side thereof, and a second opening that exposes an air inlet portion of the heat radiating member in which air from the fan enters, the second opening formed in a top face thereof; and 
     a cover member that is detachably attached to the housing and covers the second opening. 
     Preferably, in the data processing apparatus according to invention, the first opening is formed in the side facing a back of the housing and the second opening is formed in the top face of the housing at a position behind the keyboard 
     As the first opening, from which air warmed up by the heat radiating member is discharged, is formed in a side of the housing (desirably at a back-facing face of the housing) while the second opening is formed in the top face (desirably behind the keyboard on the top face), warmed air discharged from the first opening is prevented from blowing against a user and at the same time easy cleaning is enabled. 
     Preferably, also in the data processing apparatus according invention, the cover member is manually detached by operation. 
     Further preferably, in the data processing apparatus according to invention, the fan is arranged at least partially under the keyboard and the heat radiating member is arranged at a position at the back of the keyboard, and a top face of the heat radiating member is positioned higher than a top face of the fan. The data processing apparatus is desirably provided with a metal plate that spreads over the top face of the fan and the top face of the heat radiating member and is configured such that a portion thereof for covering the top face of the heat radiating member is raised by the height of the heat radiating member. The keyboard is desirably arranged on the metal plate. 
     As the top face of the heat radiating member is positioned higher than that of the fan, the disposed air inlet portion when the cover member is removed is positioned relatively high, which ensures cleaning with ease. Additionally, the top face of the fan is positioned lower relative to that of the heat radiating member, the metal plate can be placed on the fan to use the metal plate as the base of the keyboard. In this case, the metal plate can serve also as an electromagnetic shield, for example, by placing circuit board thereunder. Further, the metal plate is configured such that a portion thereof for covering the top face of the high heat radiating member is not separated but raised from the rest of the metal plate, the strength of the metal plate as well as its electromagnetic shield performance is ensured. 
     More preferably, in the data processing apparatus according to the invention, the housing has an opening for holding the cover member, the opening being formed at a position covered by the cover member, and the cover member has a projection that engages in the opening so as to be held therein, the projection being formed on a face of the cover member facing the housing when attached to the housing. Further preferably, the housing has a recess that has space for a finger or a fingernail to hold the cover member attached to the housing. 
     Also, the data processing apparatus according to the invention may have a second housing, in addition to the housing as a second housing, the second housing being connected through a hinge to the first housing at the back of the first housing such that the second housing is openable and closable relative to the first housing, and has a display screen that displays an image, such as a notebook PC. 
     Preferably, in the data processing of this invention, the cover member is formed so as to be wider than the second opening of the housing such that the cover member overlaps an edge portion that defines the second opening. 
     It is also preferable that, in the data processing of this invention, an air guide wall is provided at each of both ends of the air inlet portion, which guides air from the fan to the air inlet portion and prevents the air from leaking out off the heat radiating member, 
     wherein the edge portion defining the second opening of the housing extends to a position over the air guide walls such that the second opening is restrictedly formed within an area sandwiched between the air guide walls at both ends of the air inlet portion. 
     As described above, the apparatus according to the invention can recover coolability downgraded due to accumulated dust therein. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments of the present invention will be described below with reference to the attached drawings. 
         FIG. 1  is a perspective view of a notebook computer (hereafter referred to as note PC) when opened. 
         FIG. 2  is a perspective view of the note PC shown in  FIG. 1  when closed, as viewed obliquely from its front. 
         FIG. 3  is a perspective view of the note PC shown in  FIG. 1  when closed, as viewed obliquely from its back. 
         FIG. 4  shows a front face of the note PC shown in  FIGS. 1 through 3  when closed. 
         FIG. 5  shows a back face of the note PC shown in  FIGS. 1 through 3  when closed. 
         FIG. 6  shows a right flank of the note PC shown in  FIGS. 1 through 3  when closed. 
         FIG. 7  shows a left flank of the note PC shown in  FIGS. 1 through 3  when closed. 
         FIG. 8  shows a top face of the note PC shown in  FIGS. 1 through 3  with its cover member removed therefrom. 
         FIG. 9  is an enlarged view of a portion at the back of a keyboard on the top face of a main unit of the note PC. 
         FIG. 10  illustrates a fan and a portion of a heat radiating member with a top cover and a keyboard removed from the housing of the main unit. 
         FIG. 11  illustrates the portion of the heat radiating member as viewed at different angle from that in  FIG. 10 . 
         FIG. 12  shows a positional relationship between the fan and the heat radiating member with a metal plate removed therefrom. 
         FIG. 13  is a plane view of the heat radiating member. 
         FIG. 14  is a perspective view of the heat radiating member. 
         FIG. 15  shows heat generating components on a main circuit board. 
         FIG. 16  illustrates two heat generating components and a bottom face of the heat radiating member that contacts the heat generating components. 
         FIG. 17  shows positional relation between a CPU and a chipset different from that shown in  FIGS. 15 and 16 . 
         FIG. 18  illustrates two heat generating components, that is, the CPU and the chipset, and a bottom face of the heat radiating member that contacts the heat generating components. 
         FIG. 19  is a perspective view of a bottom face of the main unit of the notebook PC. 
         FIG. 20  shows the bottom face of the main unit of the notebook PC shown in  FIG. 19 , with the cover member for closing a hard disc drive unit loading opening removed therefrom. 
         FIG. 21  is an enlarged view of an opening for accommodating the hard disk drive unit and the hard disc drive unit housed therein. 
         FIG. 22  is a view of the hard disk drive unit as viewed at a certain angle. 
         FIG. 23  is a view of the hard disk drive unit as viewed at a different angle. 
         FIG. 24  is a view of the hard disk drive unit as viewed at another different certain angle. 
         FIG. 25  is a perspective view of a unit side connector provided in the hard disc drive unit. 
         FIG. 26  shows an apparatus side connector that is to be connected with the unit side connector provided in the hard disc drive unit. 
         FIG. 27  is a perspective view of one side of the opening in which the hard disc drive unit is housed. 
         FIG. 28  shows the state in which the hard disc drive is about to be housed by being placed in the correct position in the opening of the hard disc drive unit. 
         FIG. 29  also show the state in which the hard disc drive is about to be housed by being placed in the correct position in the opening of the hard disc drive unit. 
         FIG. 30  shows the state in which the hard disc drive unit with its back obliquely lifted is placed in the opening. 
         FIG. 31  shows a back face of the cover member for closing the opening in which the hard disc drive unit is housed. 
         FIG. 32  is a perspective view of the PC card slot  280 . 
         FIG. 33  is a perspective view of the PC card slot shown in  FIG. 32 , with the lower cover member shown in  FIG. 6  opened. 
         FIG. 34  compares the PC card slot (A) according to the embodiment of the notebook PC of the invention with a typical example of the conventional PC card slot (B) 
         FIG. 35  is a perspective view of the disc drive unit with the top cover of the housing of the main unit of the notebook PC removed therefrom. 
         FIG. 36  shows a disc drive unit accommodating section to accommodate the disc drive unit. 
         FIG. 37  shows one side-end of the disc drive unit accommodating section. 
         FIG. 38  shows the other side-end of the disc drive unit accommodating section. 
         FIG. 39  shows a sheet to be spread under a sub circuit board, with the sub circuit board and a flat cable removed therefrom. 
         FIG. 40  shows an insulation sheet that is spread under the main and sub circuit boards with the circuit boards removed therefrom. 
         FIG. 41  is an enlarged view of a portion at the back of the keyboard on the top face of the main unit of the notebook PC. 
         FIG. 42  illustrates the same portion as shown in  FIG. 41  that further exposes the air inlet portion of the heat radiating fins by removing part of the housing of the main unit. 
         FIG. 43  shows an air passage from the fan with the keyboard removed from the main unit. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Embodiment(s) of the present invention will be described below with reference to the attached drawings. 
       FIG. 1  is a perspective view of a notebook computer  10  (hereafter referred to as a notebook PC) when opened,  FIG. 2  is a perspective view of the notebook PC  10  when closed, as viewed obliquely from its front, and  FIG. 3  is a perspective view of the notebook PC  10  when closed, as viewed obliquely from its back. 
     The notebook PC  10  is composed of a main unit  20  and a display unit  30 . The display unit  30  is connected via a hinge mechanism  40  with the main unit  20  at the back of the main unit  20  so as to be openable and closable. 
     The main unit  20  has various components incorporated in the housing thereof, including circuits such as CPU, a hard disc drive unit to access a CD and a DVD loaded therein, a PC card slot to access a PC card inserted therein, a memory card slot to access various kinds of memory cards inserted therein and so on. 
     On the top face of the main unit  20 , disposed are a keyboard  21 , a touchpad  22 , right and left push buttons  22   b  and  22   a , a fingerprint sensor  23  disposed between the push buttons  22   b  and  22   a , a power button  24  disposed at the right back, plural indicator lamps  25  and plural function buttons  26  disposed at the left back. 
     Further disposed on the top face of the main unit  20  is a locking aperture  27  at a substantial center of the front thereof. The locking aperture  27  receives a locking claw  31  of the display unit  30 , when the display unit  30  is closed to overlay the main unit  20 , and the display unit  30  locks into the main unit  20  such that the display unit  30  does not easily open. To open the display unit  30 , an unlocking button  32  of the display unit  30  is to be pressed to unlock the locking claw  31  and the display unit  30  is to be lifted with a hand. Additionally, a long and narrow cover member  28  extending laterally is disposed at the back of the keyboard  21  on the top face of the main unit  20 , which will be described later in detail. 
     The display unit  30  has, in addition to the locking claw  31  and the unlocking button  32 , a display screen  33  disposed at the inside thereof and facing the main unit  20  when closed. Various images are displayed on the display screen  33  in response to instructions from the CPU of the main unit  20 . 
     The hinge mechanism  40  supports the display unit  30  such that the display unit  30  can open and close relative to the main unit  20  and can be kept opening at any degree by friction of the hinge mechanism  40 . 
       FIG. 4  shows a front face of the notebook PC  10  shown in  FIGS. 1 through 3  when closed. 
     On the flank of the front of the main unit  20 , audio output ports  201   a ,  201   b  are disposed respectively at the left and right thereof to output sound from a built-in microphone to outside the apparatus. Further, disposed are a microphone connection port  202  for connecting a microphone jack thereto, a headphone connection port  203  for connecting a headphone jack thereto, and an On/Off switch  204  for turning on/off wireless LAN function. 
       FIG. 5  shows a back face of the notebook PC  10  shown in  FIGS. 1 through 3  when closed. 
     As shown in  FIG. 5 , on the flank of the back of the main unit  20 , disposed in the order from the right to the left are a modem circuit connecting port  205 , an external monitor connecting connector  206 , air outlets  207  from which air blown from a fan inside the main unit  20  is discharged, a video output terminal  208 , a LAN connection terminal  209 , two USB connection terminals  210   a ,  210   b  and a locking aperture  211  for connecting a theft-proof wire thereto. 
     It should be noted that in  FIG. 5  heat radiating fins  241  of a heat radiating member  240  (see  FIG. 11 ) are exposed to be seen at the back of the air outlets  207 . 
       FIG. 6  shows a right flank of the notebook PC  10  shown in  FIGS. 1 through 3  when closed. 
     As shown in  FIG. 6 , on the flank of the right of the notebook PC  10 , there are disposed an AC adapter (not shown) power cable connecting port  212 , an IEEE  1394  connecting terminal  213 , a USB connecting terminal  214 , a media loading opening  215  in which plural types of storage media, four in the embodiment, can be inserted, and a PC card loading opening  216  in which plural PC cards are to be inserted. As will be described later, in the main unit  20 , upper and lower PC card slots capable of accommodating two PC cards and having corresponding upper and lower cover members  217  and  218  are disposed inside the PC card loading opening  216 . When no PC card is loaded, the cover members  217  and  218  are pressed by a spring from inside the housing of the main unit  20  so as to be closed, as shown in  FIG. 6 . The notebook PC card loading opening  216  is adapted to be opened in the following manner: when a PC card is inserted into the upper PC slot, the upper cover member  217  is pressed by the front end of the PC card and rotated such that the upper cover member  217  is lifted up around a top edge  217   a  thereof; on the other hand, when a PC card is inserted into the lower PC slot, the lower cover member  218  is pressed by the front end of the PC card and rotated such that the lower cover member  218  goes down around a bottom edge  218   a  thereof. In order to pull the inserted PC card from the PC card loading opening  216 , an eject button  219  disposed next to the PC card loading opening  216  is to be pressed. 
       FIG. 7  shows a left flank of the notebook PC  10  shown in  FIGS. 1 through 3  when closed. 
     On the flank of the left of the main unit  20 , arranged is an end face of a disc drive unit  220  to access a CD and a DVD loaded therein. Pressing an eject button  221  causes a tray to pop out from inside the housing of the main unit  20 . Placing CD and DVD on the tray and pushing it enables the CD and DVD to be accessed by the disc drive unit  220 . When removing the CD and DVD, the eject button  221  is to be pressed similarly. 
     Incidentally, an opening of the same shape as that of the end face of the disc drive unit  220  is formed in the housing of the main unit  20 . Thus, when doing a maintenance check, the whole of the disc drive unit  220  can be pulled out from inside the housing of the main unit  20  and reinserted therein. 
     So far, the notebook PC  10  as a whole has been described. In the following, the details of each section of the notebook PC  10  will be described. 
     (Structure of Air Inlet Portion of Heat Radiating Fins) 
       FIG. 8  shows a top face of the notebook PC  10  shown in  FIGS. 1 through 3  with its cover member removed therefrom.  FIG. 9  is an enlarged view of a portion at the back of a keyboard  21  on the top face of the main unit  20  of the notebook PC  10 . 
     An elongated cover member  28 , as shown in  FIG. 1 , is disposed at the back of the keyboard  21  on the top face of the main unit  20 . Opening the cover member  28  exposes an opening  231  formed inside the housing of the main unit  20 . An air inlet portion  241   a  of the heat radiating fins  241  of the heat radiating member  240  (see  FIG. 11 ) can be seen through the opening  231 . The heat radiating member  240  will be described later in detail. The air inlet portion  241   a  is likely to be covered in dust because air from the fan  250  blows against it. The accumulated dust in the air inlet portion  241   a  prevents air flow from the fan  250 , downgrading coolability, leading to rise in temperature inside the housing of the main unit  20  and thus possibly resulting in malfunction and failure of the notebook PC  10 . However, the notebook PC  10  has such a configuration that the air inlet portion  241   a  can be exposed by taking off the cover member  28  to enable easy removal of dust accumulated therein. The opening  231 , through which the air inlet portion  241   a  of the heat radiating fins  241  can be seen, is closed by the cover member  28 , whose backside is shown in  FIG. 9 , which has positioning claws  281  and  282  at ends thereof and locking claws  283 ,  284  and  285  at three separate positions at substantially center thereof. 
     The positioning claws  281  and  282  engage in positioning holes  232  and  233  formed in the housing of the main unit  20  while the locking claws  283 ,  284  and  285  respectively engage in locking holes  234 ,  235  and  236  formed in the housing of the main unit  20 , so that the cover member  28  is attached to the housing of the main body so as to close the opening  231 . 
     Additionally, a recess  237  with space for a finger or a nail to be placed therein is formed in the housing of the main unit  20  in order to enable easy taking off of the cover member  28  attached to the housing. Thus, the cover member  28  can be easily taken off by placing a finger or a fingernail under the recess  237  and lifting up the cover member  28 . 
       FIG. 10  illustrates a fan and a portion of the heat radiating member  240  with a top cover and the keyboard  21  of the main unit  20  removed therefrom.  FIG. 11  illustrates the portion of the heat radiating member  240  as viewed at different angle from that in  FIG. 10 . 
     A main circuit board  251  mounted with various circuit components is arranged around the fan  250 . A metal plate  252  with several holes formed therein is arranged above the fan  250 , the main circuit board  251 , and the heat radiating member  240 . A top face of the heat radiating member  240  stands higher than that of the fan  250 , so that a shield portion  252   a  formed in the metal plate  252  for covering the top face of the heat radiating member  240  is raised from the level of the rest of the metal plate  252 . 
     The metal plate  252  serves as an electromagnetic shield as well as a base for the keyboard  21  (see  FIG. 1 ) that is arranged on the metal plate  252 . 
       FIG. 12  shows a positional relationship between the fan  250  and the heat radiating member  240  with the metal plate  252  removed therefrom. 
     Two kinds of LSIs, that is, what is called CPU and chipset are disposed under the heat radiating member  240 . The heat radiating member  240  serves for radiating heat generated by the two LSIs, which will be described later in detail. 
     Air blown from the fan  250  enters the air inlet portion  241   a  to reach the heat radiating fins  241  and then is warmed up while passing between the heat radiating fins  241  by absorbing heat therefrom and exits from the air outlets  207  (also see  FIG. 5 ) formed in the flank of the back of the main unit  20 . 
     (Structure of Heat Radiating Member) 
     The heat radiating member  240  includes a flat base section (hereafter referred to as “a base plate”)  242 , the multiple pieces of radiating fins  241  that are fixed to and stand on the base plate  242  and a pair of arms (hereafter referred to as “arm plates”)  243 ,  244  that extend horizontally at both ends of the base plate  242 . The arm plates  243 ,  244  include fasteners  243   a ,  243   b , and  244   a ,  244   b  respectively disposed at the front and the back thereof for fastening the heat radiating member  240  with screws. Additionally, the heat radiating member  240  has a fixed section (hereafter referred to as “a fixed plate”)  245  that stands at both ends of the heat radiating fins  241  and links the both ends by extending over the heat radiating fins  241  like a bridge. The pair of arm plates  243 ,  244  are formed by extending the fixed plate  245 . 
     The manufacturing process of the heat radiating member  240  is as follows: solder is applied to the bottom of each of the heat radiating fins  241  to place them on the top face of the base plate  242 ; then, solder is applied to the top of each of the heat radiating fins  241  to attach the heat radiating fins  241  and the base plate  242  to the fixed plate  245 , which are subjected to solder-joint with a furnace to complete manufacturing. 
     Incidentally, the fasteners  243   a ,  234   b , and  244   a ,  244   b  respectively have a structure of a fixed pedestal with a spring incorporated therein. Thus, the heat radiating member  240  is pressed against heat radiating components by means of springs when fastened with screws. Such a structure is well known art and thus further explanation is omitted. 
       FIG. 15  shows heat generating components on the main circuit board  251 . 
       FIG. 15  illustrates CPU  253   a  and chipset  254   a  disposed near the CPU  253   a  that are heat generating components to be cooled by the heat radiating member  240  shown in  FIG. 14 . As the CPU  253   a  generates larger amount of heat than the chipset  254   a , it is placed so as to be efficiently cooled by the heat radiating member  240 . More particularly, the CPU  253   a  is disposed under the base plate  242 , so that heat generated by the CPU  253   a  is conducted via the base plate  242  to the heat radiating fins  241  from the bottom thereof. On the other hand, the chipset  254   a  is disposed under one of arm plates  243 ,  244  (in this case the arm plate  243 ), so that heat generated by the chipset  254   a  is conducted via the fixed plate  245  to the heat radiating fins  241  from the top thereof. 
       FIG. 16  illustrates two heat generating components, that is, the CPU  253   a  and the chipset  254   a , and a bottom face of the heat radiating member  240  that contacts the heat generating components. 
     The heat radiating member  240  is arranged on the CPU  253   a  and the chipset  254   a  so as to be in contact with them via thermal grease. When the heat radiating member  240  is attached to the CPU  253   a  and the chipset  254   a  by screwing the fasteners  243   a ,  243   b  and  244   a ,  244   b  of the arm plates  243 ,  244  in the four respective holes  251   a ,  251   b  and  251   c ,  251   d  formed in the main circuit board  251 , a substantial center “a” of the CPU  253   a  contacts a substantial center “a′” of the base plate  242  of the heat radiating member  240 , while a substantial center “b” of the chipset  254   a  contacts a substantial center “b′” having a downward projection of the arm plate  243 . The downward projection of the arm plate  243  will be described later in detail. 
       FIG. 17  show positional relation between a CPU and a chipset different from that shown in  FIGS. 15 and 16   
     The notebook PC  10  according to the embodiment (see  FIG. 1 ) includes two kinds of notebook PCs mounted with two kinds of CPUs and chipsets of different manufacturers.  FIGS. 15 and 16  show positional relation between CPU  253   b  and chipset  254   b  of a first kind of the notebook PCs while  FIG. 17  shows that of a second kind of the notebook PC. 
     The difference of positional relation between the CPU  253   b  and the chipset  254   b  between  FIGS. 15 ,  16  and  FIG. 17  lies in that the position of the CPU  253   a  is roughly replaced with the chipset  254   a.    
       FIG. 18  illustrates two heat generating components, that is, the CPU  253   b  and the chipset  254   b , and a bottom face of the heat radiating member that contacts the heat generating components. 
     Similarly to the notebook PC  10  shown in  FIG. 16 , the heat radiating member  240  is arranged on the CPU  253   b  and the chipset  254   b  so as to be in contact with them via thermal grease. When the heat radiating member  240  is attached to the CPU  253   b  and the chipset  254   b  by screwing the fasteners  243   a ,  243   b  and  244   a ,  244   b  of the arm plates  243 ,  244  in the four respective holes  251   a ,  251   b  and  251   c ,  251   d  formed in the main circuit board  251 , a substantial center “c” of the CPU  253   b  contacts a substantial center “c′” of the base plate  242  of the heat radiating member  240 , while a substantial center “d” of the chipset  254   b  contacts a substantial center “d′” of the arm plate  244 . 
     The height of the chipset  254   a  with reference to that of the CPU  253   a , in the first kind of the notebook PC shown in  FIG. 16 , differs from the height of the chipset  254   b  with reference to that of the CPU  253   b  in the second kind of the notebook PC shown in  FIG. 18 . That is why the arm plate  243  constituting the heat radiating member  240  has the downward projection  243   c  to offset difference in height between the chipsets  254   a  and  254   b  so that the heat radiating member  240  can contact both the chipsets  254   a  and  254   b.    
     According to the embodiment, the heat radiating member  240  has such a structure that difference in height between the CPU  253   a  and  253   b  is offset by the amount of contraction and extension of the springs of the fasteners  243   a ,  243   b  and  244   a ,  244   b , while difference in height between the chipsets  254   a  and  254   b  is offset by the shape of the arm plate  243 . 
     Such a structure enables the heat radiating member  240  of the same shape to be used for the two kinds of notebook PCs, by aligning the holes  251   a ,  251   b  and  251   c ,  251   d  formed in the main circuit board  251  of the notebook PC  10  with the fasteners  243   a ,  243   b  and  244   a ,  244   b  of the arm plates  243 ,  244  of the heat radiating member  240 . 
     (Structure of Hard Disc Drive Unit Loading Opening Portion) 
       FIG. 19  is a perspective view of a bottom face of the main unit  20  of the notebook PC  10 . 
       FIG. 19  shows a cover member  261  for closing the hard disc drive unit loading opening, a cover member  262  for closing a battery loading opening and a cover member  263  for closing a memory card loading opening. 
       FIG. 20  shows the bottom face of the main unit  20  of the notebook PC shown in  FIG. 19 , with the cover member  261  for closing the hard disc drive unit loading opening removed therefrom. 
     As shown in  FIG. 20 , an opening  265  for housing a hard disc drive unit  270  is formed in the bottom face of the main unit  20  and the hard disc drive unit  270  is housed therein. 
       FIG. 21  is an enlarged view of the opening  265  and the hard disc drive unit  270  housed therein. 
     In order to remove the hard disc drive unit  270  from the opening  265 , two screws  264   a  and  264   b  are first to be disengaged to pull a sheet  271  in the direction indicated by the arrow A, thereby disengaging a unit side connector  273  (see  FIG. 22 ), which will be described later. Then, the hard disc drive unit  270  is ready to be removed from the opening  265 . Alternatively, in order to house the hard disc drive unit  270  in the opening  265 , the hard disc drive unit  270  is first to be placed on a position little displaced from the position indicated by  FIG. 21  toward the direction indicated by the arrow A. Then, pressing the hard disc drive unit  270  in the direction opposite the direction indicated by the arrow A causes the unit side connector  273  to be engaged and then, by screwing the hard disc drive unit  270  with the two screws  264   a  and  264   b , the hard disc drive unit  270  is appropriately housed in the opening  265 . 
     It should be noted that the opening  265  has a pair of projections  266   a  and  266   b  projecting inside and disposed at both sides thereof. The projections  266   a  and  266   b  interfere with the hard disc drive unit  270 , if the unit side connector  273  is to be engaged while the back end (opposite the unit side connector  273 ) of the hard disc drive unit  270  is lifted obliquely or the whole of the hard disc drive unit  270  is lifted from the level of the opening  265 . Thus, the projections  266   a  and  266   b  prevent wrong connection of the unit side connector  273  and failures such as bent back connector pins. Additionally, the opening  265  has projections  267   a ,  267   b , and  268   a ,  268   b  disposed at both sides thereof that serve for engaging the cover member  261  (see  FIGS. 19 and 31 ) for the opening  265 . 
       FIGS. 22 through 24  illustrate the hard disc drive unit  270  as viewed from different angles from that in  FIG. 21 .  FIG. 25  is a perspective view of the unit side connector  273  provided in the hard disc drive unit  270 . 
     As shown in  FIGS. 22 through 24 , the hard disc drive unit  270  is provided with a metal frame  272  that is fastened to the hard disc drive unit  270  with screws in the side portions thereof that are formed by extending the metal frame  272  and bending it at the both edges. The metal frame  272  serves for maintaining strength of the hard disc drive unit  270  as well as shielding electromagnetic force of its internal hard disc and magnetic disc. Multiple holes formed in the metal frame  272  are intended for reduction in weight while maintaining strength and shielding performance. 
     Additionally, the metal frame  272  also serves for preventing wrong engagement of the unit side connector  273 . When the unit side connector  273  is to be engaged while the hard disc drive unit  270  is in undesired postures, for example, lifted obliquely as described above, interfering sections  272   a  and  272   b  of the metal frame  272  interfere with the projections  266   a  and  266   b  of the opening  265 . 
     Further, the hard disc drive unit  270  is provided with the unit side connector  273  at the front end thereof. As shown in  FIG. 25 , the unit side connector  273  has multiple connection pins  273   a  aligned in two rows. 
       FIG. 26  shows an apparatus side connector  269  that is to be connected with the unit side connector  273  provided in the hard disc drive unit  270 . 
     The apparatus side connector  269  has multiple pin insertion holes  269   a  aligned in two rows to receive the corresponding connection pins  273   a  aligned in two rows of the unit side connector  273  provided in the hard disc drive unit  270 . 
       FIG. 27  is a perspective view of one side of the opening  265  in which the hard disc drive unit  270  is housed. 
     As shown in  FIG. 27 , the side of the opening  265  is configured such that the metal frame  272  (see  FIG. 22 ) goes under the projection  266   a  disposed at the side of the opening  265  when the hard disc drive unit  270  is housed in the opening  265 . The same holds true for the projection  266   b  at the other side of the opening  265 . 
       FIGS. 28 and 29  show the state in which the hard disc drive unit  270  is about to be housed in the correct position in the opening  265 . 
     The hard disc drive unit  270  is placed in the position indicated in  FIGS. 28 and 29 , and pressed in the direction indicated by the arrow B, thereby making the unit side connector  273  to be engaged with the apparatus side connector  269 . As the hard disc drive unit  270  is placed in the correct position, the interfering sections  272   a ,  272   b  of the metal frame  272  of the hard disc drive unit  270  do not interfere with the projections  266   a  and  266   b  provided in the opening  265 , so that the hard disc drive unit  270  goes under the projections  266   a  and  266   b.    
       FIG. 30  shows the state in which the hard disc drive unit  270  with its back obliquely lifted is placed in the opening  265 . 
     If the hard disc drive unit  270  is pushed in the direction indicated by the arrow B while keeping the posture shown in  FIG. 30 , the interfering section  272   a ,  272   b  interfere with the projections  266   a ,  266   b , resulting in failure of engagement between the unit side connector  273  and the apparatus side connector  269 . Thus, it is possible to prevent failures such as bent-back of the connection pins  273   a  due to forced engagement. 
       FIG. 30  shows the case in which the back of the hard disc drive unit  270  is obliquely lifted. However, the same holds true for the case in which the whole of the hard disc drive unit  270  is lifted from the opening  265  in a horizontal posture. Further, there may be a case in which the connection pins  273   a  aligned in the lower row of the unit side connector  273  are inserted in the insertion holes  269   a  aligned in the upper row of the apparatus side connector  269 . In such a case, however, the interfering section  272   a ,  272   b  are to be positioned over the projections  266   a ,  266   b , and thus the hard disc drive unit  270  cannot be housed in the opening  265  nor the cover member  261  (see  FIG. 19 ) for closing the opening  265  can be attached. Accordingly, it is easy to grasp that the hard disc drive unit  270  is not properly housed in the opening  265 , making it possible to prevent such a wrong engagement. Additionally, there may be a case that the hard disc drive unit  270  is lifted so obliquely that the interfering section  272   a ,  272   b  can go over the projections  266   a ,  266   b , and the connection pins  273   a  aligned in the lower row of the unit side connector  273  can be forcibly inserted in the insertion holes  269   a  aligned in the upper row of the apparatus side connector  269 . In such a case, however, the interfering section  272   a ,  272   b  are to be positioned over the projections  266   a ,  266   b , and thus the hard disc drive unit  270  cannot be housed in the opening  265  nor the cover member  261  (see  FIG. 19 ) for closing the opening  265  can be attached. Accordingly, it is easy to grasp that the hard disc drive unit  270  is not properly housed in the opening  265 . 
     When the hard disc drive unit  270  is housed in the opening  265  in the correct position, the interfering section  272   a ,  272   b  are positioned under the projections  266   a ,  266   b . Accordingly, when the hard disc drive unit  270  is removed from the opening  265 , it is not possible to lift the back of the hard disc drive unit  270  before releasing the engagement between the connectors  269  and  273 . Thus, it is possible to secure that the unit side connector  273  is properly pulled from the apparatus side connector  269 . 
       FIG. 31  shows a back face of the cover member  261  for closing the opening  265  in which the hard disc drive unit  270  is housed. 
     On the back face of the cover member  261 , disposed are two projections  301   a ,  301   b  projecting toward the depth of the opening  265  (see  FIG. 21 ), two projecting claws  302   a  and  302   b  engaging the two projections  267   a  and  267   b  that are disposed at both sides of the opening  265  and projecting inside thereof, and two engaging claws  303   a ,  303   b  engaging the two projections  268   a ,  268   b  that project from the back end of the opening  265 . Additionally, the cover member  261  has a hole  304  formed at the back side thereof. The cover member  261  closes the opening  265 , as shown in  FIG. 19 , by engaging the two projections  301   a ,  301   b , the projecting claws  302   a ,  302   b , and the engaging claws  303   a ,  303   b  of the cover member  261  with the corresponding parts of the opening  265  and by screwing in the hole  304 . 
     (Structure of PC Card Slot) 
       FIG. 32  is a perspective view of the PC card slot  280 ,  FIG. 33  is a perspective view of the PC card slot  280  shown in  FIG. 32 , with the lower cover member shown in  FIG. 6  opened. 
     The PC card slot  280  is disposed in the housing of the notebook PC  10  inside the PC card loading opening  216  (see  FIG. 6 ) formed in the flank of the right side of the notebook PC  10 , such that it faces the PC card loading opening  216 . The PC card slot  280  is consisted of a metal frame and configured to accommodate two PC cards vertically which are inserted in the PC card loading opening  216 . A circuit board mounted with circuits for accessing a PC card inserted in the PC card slot  280  is provided under the PC card slot  280 . An insulation sheet  2801 , whose front end  2801   a  extends close to the PC card loading opening  216  (see  FIG. 6 ), is spread between the circuit board and the PC card slot  280  of metal frame for securing electrical insulation therebetween. 
     As described in  FIG. 6 , the PC card loading opening  216  is configured such that the upper and lower cover members  217  and  218  are openably closed. A PC card is received by the PC card loading opening  216  as follows: when a PC card is inserted into the PC card loading opening  216 , the upper cover member  217  is pressed by the front end of the PC card and rotated such that the upper cover member  217  is lifted up around the top edge  217   a  thereof; when the lower cover member  218  is pressed by the front end of the PC card, the lower cover member  218  is rotated such that the lower cover member  218  goes down around the bottom edge  218   a  thereof. 
       FIG. 33  shows the state that the lower cover member  218  of the two cover members for closing the PC card loading opening  216  is opened. The opened cover member  218  covers the front end  2801   a  of the insulation sheet  2801 , which prevents the PC card inserted in the PC card loading opening  216  from abutting the front end  2801   a  of the insulation sheet  2801  and thus the insulation sheet  2801  from being turned up. 
       FIG. 34  compares the PC card slot (A) according to the embodiment of the notebook PC of the invention with a typical example of the conventional PC card slot (B). 
     In the case of the typical conventional PC card slot (B), the front end of the insulation sheet  2801  is adhered onto a circuit board thereunder by using a double side tape. The front end of the circuit board is flush with the front end  2801   a  of the insulation sheet  2801 . Thus, if a PC card is inserted downward and obliquely, the front end of the PC card abuts the front end  2801   a  of the insulation sheet  2801 . Frequent occurrence of such abutting causes the front end  2801   a  of the insulation sheet  2801  to be turned up and thereby damaging the circuit board by the front end of the PC card, leading to malfunction of the apparatus. 
     On the other hand, in the notebook PC of the embodiment, the circuit board is shorter relative to the typical conventional PC card slot (B), as indicated by dotted lines in  FIG. 34  (A), and the insulation sheet  2801  is extended closer to the PC card loading opening  216  (see  FIG. 6 ). Accordingly, as shown in  FIG. 32 , the front end  2801   a  of the insulation sheet  2801  is covered by the downwardly opened cover member  218 , which prevents the insulation sheet  2801  from being turned up and thereby prevents damage of the circuit board. Additionally, the need to adhere the insulation sheet  2801  onto the circuit board is eliminated, resulting in decrease in the number of assembly works. 
     (Structure of Disc Drive Unit) 
       FIG. 35  is a perspective view of the disc drive unit  220  with the top cover of the housing of the main unit  20  of the notebook PC  10  removed therefrom. 
     The disc drive unit  220 , as shown in  FIG. 7 , is inserted from the opening formed in the left-side flank of the housing of the main unit  20  to be housed therein. 
       FIG. 36  shows a disc drive unit accommodating section to accommodate the disc drive unit  220 ,  FIG. 37  shows one side-end of the disc drive unit accommodating section  310 , and  FIG. 38  shows the other side-end thereof. 
     The disc drive unit  220  is accommodated in the disc drive unit accommodating section  310  while guided by rails  311 ,  312  in the both sides thereof and inserted into the position where a connector (not shown) of the disc drive unit  220  is engaged with an apparatus side connector  313 . The face of the inserted disc drive unit  220  becomes flush with that of the housing of the main unit  20  of the notebook PC  10  as shown in  FIG. 7 . 
     The main circuit board  251  (see  FIG. 38 ) and a sub circuit board  320  (see  FIG. 36 ) are disposed at the both sides of the disc drive unit accommodating section  310 . Thus, a flat cable  321  for electrically connecting the main circuit board  251  and the sub circuit board  320  is laid across the disc drive unit accommodating section  310 . The flat cable  321  may be a flexible wiring board. The flat cable  321  is arranged under the disc drive unit  220  after the disc drive unit  220  is accommodated in the disc drive unit accommodating section  310 . Thus, without taking any precaution, the disc drive unit  220  inserted into the disc drive unit accommodating section  310  may be caught on the flat cable  321 , leading to failures such as disconnection. Therefore, a sheet  322  is provided such that the flat cable  321  is wrapped by the sheet  322  folded back at a position close to the opening for the disc drive unit  220 . The sheet  322  is adhered to a face of the disc drive unit accommodating section  310  at a position away from the opening for the disc drive unit  220  by using an adhesive tape  323 . 
     As the flat cable  321  is wrapped by the sheet  322 , it is possible to prevent the disc drive unit  220  inserted into the disc drive unit accommodating section  310  from being caught on the flat cable  321  and thus occurrence of failures such as disconnection can be prevented. 
       FIG. 39  shows a sheet to be spread under the sub circuit board  320 , with the sub circuit board  320  and the flat cable  321  removed therefrom. 
     An insulation sheet  324  is spread under the sub circuit board  320  for insulating electrical connection between the sub circuit board  320  and the housing of the main unit  20 . It should be noted that the sheet  322 , which wraps the flat cable  321  as shown in  FIGS. 36 and 37 , is formed by extending the insulation sheet  324 . This suppresses increase in the number of the components. 
       FIG. 40  shows an insulation sheet that is spread under the main and sub circuit boards  251 ,  320 , with the circuit boards  251 ,  320  removed therefrom. 
     An insulation sheet  325  is laid under the main circuit board  251 . The insulation sheet  324  laid under the sub circuit board  320  and the insulation sheet  325  laid under the main circuit board  251  overlap at least at the front end  324   a  of the insulation sheet  324  that extends across the disc drive unit accommodating section  310  to the side of the main circuit board  251 . 
     According to the embodiment, it is intended to prevent the disc drive unit  220  inserted in the disc drive unit accommodating section  310  from being caught on the flat cable  321 , by using the insulation sheet  324  for the sub circuit board  320  to wrap the flat cable  321  running across the disc drive unit accommodating section  310 . 
     Next, description will be made on a modification of the notebook PC that has been explained so far. 
     Except the features described below, this modification is identical with the notebook PC that has been described. 
       FIG. 41  is an enlarged view of a portion at the back of the keyboard on the top face of the main unit of the notebook PC  10 .  FIG. 41  corresponds to  FIG. 9  of the afore-mentioned embodiment. 
     As shown in  FIG. 41 , the width W 1  between grooves that receive the cover member  28  shown in  FIG. 1  is wider than the width W 2  of the opening  231 . Further, edge portions  239   a  and  239   b  that define the opening  231  of the main unit extend to a position inside the grooves such that the edge portions  239   a  and  239   b  are overlapped by the cover member  28  when closed and the opening  231  is located inside the grooves in the width direction. 
     When the cover member  28  is placed in the grooves to close the opening  231 , the cover member  28  overlaps the edge portions  239   a  and  239   b . If, for example, the cover member  28  does not overlap the edge portions  239   a  and  239   b , foreign matter may enter the apparatus from a gap between the cover member  28  and the edge portions  239   a  and  239   b  of the opening  231 . Additionally, air from the fan  250  (see  FIG. 10 ) to the air inlet portion  241   a  of the heat radiating fins  241  may leak out from the gap. However, this modification can eliminate such possibilities. 
       FIG. 42  illustrates the same portion as shown in  FIG. 41  that further exposes the air inlet portion of the heat radiating fins by removing part of the housing of the main unit.  FIG. 43  shows an air passage from the fan with the keyboard removed from the main unit. 
     Air guide walls  238   a  and  238   b  are formed at both ends of the air inlet portion  241   a  of the heat radiating fins  241  that constitutes the heat radiating member  240 . The air guide walls  238   a  and  238   b  serve to prevent air from the fan  250  (see  FIG. 43 ) from leaking out off the heat radiating member  240 . 
     Here, the length L 1  of the opening  231  shown in  FIG. 41  is shorter than the distance L 2  between the air guide walls  238   a  and  238   b  of the air inlet portion  241   a . Thus, the opening  241  is formed within the area sandwiched between the air guide walls  238   a  and  238   b.    
     If, for example, the opening  231  is so wide that the air guide walls  238   a  and  238   b  can be seen from the opening  231 , a gap is formed between the air guide walls  238   a , 238   b  and the back surface of the cover member even when the opening  231  is closed by the cover member. Consequently, air from the fan may enter the housing through the gap, which results in entrance of the dust accompanying the air into the housing as well as downgraded coolability as part of air from the fan leaks out. 
     On the other hand, in this modification, edge portions  239   c  and  239   d  of the main unit housing that define the opening  231  extend to a position over the air guide walls  238   a  and  238   b , so that the opening  241  is restrictively formed within the area sandwiched between the air guide walls  238   a  and  238   b.    
     Thus, it is possible to prevent leakage of air from the fan and carriage of the dust into the housing as well as downgrading of coolability.