Abstract:
An electronic apparatus including a housing having an air outlet and a heat generating component in the housing, a heat sink in the housing and having heat radiating fins arrayed. The apparatus includes heat radiating fins having air flow paths between adjacent pairs of the heat radiating fins, and a fan in the housing. The fan feeds air to an air inlet of the heat sink to exhaust heat of the heat radiating fins from the air outlet of the housing. The air outlet of the housing has openings arrayed which divide the air flow paths formed between the pairs of heat radiating fins.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is related to and claims priority to Japanese Patent Application No. 2007-173353 filed on Jun. 29, 2007 in the Japan Paten Office, the entire contents of which are incorporated herein by reference. 
       BACKGROUND 
       [0002]    1. Field 
         [0003]    The embodiments discussed herein are related to electronic devices. There are demands with electronic devices such as personal computers for even faster processing speed and greater variety of functions equipped. In order to meet such demands, electronic components in an electronic device have increasingly high performance and high density resulting in an increase of heat generated in the electronic device. Heat accumulated in an electronic device may cause a problem of deterioration of the electronic components and performance. Heat generated in an electronic device needs to be radiated efficiently. 
         [0004]    A heat radiating mechanism for radiating heat in an electronic device is used which includes a heat sink and heat radiating fins. The heat sink absorbs heat generated by the electronic components and conducts the heat to an outlet provided in the housing of the electronic device. By feeding air to the outlet, the heat radiating fins make the air absorb heat of the heat sink and the air is exhausted from the outlet. A heat sink may include a heat radiating member and a heat conducting member The heat radiating member has a plurality of heat radiating fins arrayed at equal intervals. The heat conducting member has a broad surface for conducting heat to the heat radiating member. The arrangement is such that the heat conducting member contacts the electronic components and the heat radiating member faces the outlet. The heat radiating member of the heat sink is interposed between the outlet and a fan which is arranged to feed air to the outlet. Such a heat radiating mechanism being equipped in an electronic device, the heat conducting member of the heat sink efficiently absorbs heat generated by the electronic components and conducts the heat to the heat radiating member, where air from the fan goes through the spaces between each of the plurality of heat radiating fins. As a result, air efficiently absorbs heat and then is exhausted from the outlet, which improves the efficiency of the heat radiation. 
         [0005]    2. Description of the Related Art 
         [0006]    Conventionally, a heat sink device can have an auxiliary heat radiating member including a plurality of heat radiating fins in the heat sink nearer the fan than the heat radiating member. The plurality of heat radiating fins can be arrayed obliquely with respect to the array of the plurality of heat radiating fins which compose the heat radiating member. Air from the fan may be dispersed by the auxiliary heat radiating member and then enters into the heat radiating member. In this way, this heat sink device can radiate the heat of each of the plurality of heat radiating fins. 
         [0007]    A heat radiating member may include a flow path for air formed by the spaces between each of a plurality of heat radiating fins. Air from the fan enters from an air inlet that faces the fan and flows to an air outlet which faces the outlet of the housing to be exhausted out of the housing. If dust or the like caught by the fan clogs the air inlet of the heat radiating member at this time, sufficient air can not be fed into the air flow path between the fins. As a result, the efficiency of the heat radiation may be lowered. An approach to lessen this problem, is to make the interval of the heat radiating fins larger so that dust caught by the fan does not clog the air inlet. 
         [0008]    However, if the interval of the heat radiating fins is large, foreign matter entering from the outlet of the housing may pass through the heat radiating member. Thus, the foreign matter may reach the precise electronic components leading to a failure of the electronic device e.g., s a short circuit. 
       SUMMARY 
       [0009]    According to an aspect of an embodiment, an electronic device includes a housing including an air outlet, a heat generating component in the housing and a heat sink in the housing. The heat sink includes a heat radiating member and a heat conducting member. The heat radiating member may includes plurality of heat radiating fins arrayed, the plurality of heat radiating member fins may include a plurality of air flow paths formed between adjacent pairs of the heat radiating fins. An air outlet may face the air outlet of the housing and an air inlet may be located in a side remote from the air outlet of the heat radiating fins. The heat conducting member contacts the heat generating component to absorb heat and conducts the heat to the heat radiating member. A fan may be in the housing feeding air to the air inlet of the heat radiating member to exhaust heat of the heat radiating fins from the air outlet of the housing. The air outlet of the housing may include a plurality of openings arrayed that divide the air flow paths formed between the pairs of heat radiating fins of the heat radiating member, as viewed in the direction looking from outside the housing to the air outlet. 
         [0010]    These together with other aspects and advantages which will be subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0011]      FIG. 1  illustrates a personal computer which is an example embodiment of an example electronic device; 
           [0012]      FIG. 2  illustrates an example personal computer with a display unit closed over a main body unit; 
           [0013]      FIG. 3  illustrates an example personal computer with the display unit rotated substantially 90 degrees with respect to the main body unit; 
           [0014]      FIG. 4  illustrates an example personal computer, the display unit being overlaid on the main body unit with the display screen facing upward; 
           [0015]      FIG. 5  illustrates an example internal configuration of an example personal computer; 
           [0016]      FIG. 6  illustrates an example internal construction of the main body unit; 
           [0017]      FIG. 7  illustrates an example heat sink; 
           [0018]      FIG. 8  illustrates an example relationship between a flow path of a heat radiating member and an outlet; and 
           [0019]      FIG. 9  is illustrates an example outlet of the main body unit with the heat sink 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS  
       [0020]      FIG. 1  illustrates an example personal computer that is an example embodiment of an electronic device. 
         [0021]    The personal computer  10  illustrated in  FIG. 1  may include as an input device an electromagnetic induction type digitizer mounted on the back side of a display screen  31 , and detect a position on the display screen  31  indicated by a stylus. By such an example configuration, the personal computer  10  may input by indication. This input device may be a touch panel mounted on the display screen  31 , instead of the digitizer and stylus. 
         [0022]    The personal computer  10  may include a main body unit  20  and a display unit  30 . The display unit  30  may be connected to the main body unit  20  by a biaxial connector unit  40  so as to be openable and closable in the direction of an arrow A-A and rotatable in the direction of an arrow B-B (about a rotational axis perpendicular to the main body unit  20 ) with respect to the main body unit  20 .  FIG. 1  illustrates the personal computer  10  in a state in which the display unit  30  is opened with respect to the main body unit  20  (an open state). This open state may correspond is a first state of use. The main body unit  20  is an example of a processing unit. The display unit  30  is an example of a display unit. The connecting portion  40  is an example of a connector member. 
         [0023]    The main body unit  20  may include a keyboard  21 , a track pad  22 , a left click button  23  and a right click button  24 . The main body unit  20  further may include a display unit receiving member  34  for preventing rattling of the display unit  30 . The display unit receiving member  34  is made of rubber, for example. The main body unit  20  also may include on one side thereof an opening and closing cover  26   a  for an optical disk drive  26  in which an optical disk such as a CD or DVD is mounted to be driven and accessed. The opening and closing cover  26   a  may include an eject button  26   b  which is pressed to open the opening and closing cover  26   a.  The keyboard  21  is an example of a keyboard. 
         [0024]    The display unit  30  of the personal computer  10  may include on the front surface thereof a display screen  31 . The display unit  30  may include several press buttons  32  in the right end below the display screen  31 . The display unit  30  also may include on the left end thereof a fingerprint sensor  33  which performs fingerprint authentication by being traced with a fingertip. The display screen  31  is an example of a display screen. In the open state illustrated in  FIG. 1 , information is displayed on the display screen  31  with the direction of the rotational axis B-B of the display unit  30  as the up-and-down direction. 
         [0025]      FIG. 2  illustrates a personal computer with the display unit closed over the main body unit. In  FIG. 2 , the display unit  30  is in a state of being overlaid on the main body unit  20  with the display screen  31  (see  FIG. 1 ) facing the main body unit  20 . Hereafter, this state is referred to as a first closed state. 
         [0026]      61  Upon closing the display unit  30  along the direction of the arrow A from the open state illustrated in  FIG. 1 , the personal computer  10  gets in the first closed state, where the display screen  31  may be hidden inside and the back surface with respect to the display screen  31  may be exposed outside, as illustrated in  FIG. 2 . The personal computer  10  in the first closed state can avoid staining or breakage of the display screen  31 , providing portability. 
         [0027]    As illustrated in  FIG. 2 , an outlet  27  is provided in a side of the main body unit  20 . The outlet  27  radiates heat generated by various electronic components contained in the main body unit  20 . The outlet  27  includes of a plurality of slits  27   a  extending obliquely with respect to the thickness direction of the main body unit  20 . The outlet  27  is an example of an air outlet. The slit  27   a  is an example of an opening. 
         [0028]    The hot air which has absorbed heat in the main body unit  20  is exhausted from the outlet  27 . Since the outlet  27  is provided in a side of the main body unit  20 , it will not interfere with operation by a user. 
         [0029]      FIG. 3  illustrates a personal computer with the display unit rotated substantially  90  degrees with respect to the main body unit. 
         [0030]    The display unit  30  of the personal computer  10  can be rotated from the state illustrated in  FIG. 1  via the state illustrated in  FIG. 3  until the back side of the display screen  31  faces the front. 
         [0031]      FIG. 4  illustrates a personal computer, the display unit being overlaid on the main body unit with the display screen facing upward. The personal computer  10  gets in a second closed state illustrated in  FIG. 4  upon the display unit  30  is overlaid on the main body unit with the back surface thereof with respect to the display screen  31  facing the main body unit  20  after the display unit  30  may include been rotated from the state illustrated in  FIG. 1  via the state illustrated in  FIG. 3  until the back side of the display screen  31  faces the front. This second closed state is an example of a second state of use. Hereafter, “tablet mode” refers to an operation mode where the personal computer  10  is used in the second closed state. 
         [0032]    As described above, the display screen  31  is a display screen with a pen input function, the display screen  31  having on the back side thereof an electromagnetic induction type digitizer for detecting the indicated position on the display screen. Usually, a user holds s the personal computer  10  which is in the tablet mode with one arm, and operates the display screen with a stylus (not illustrated) in the other hand. In relation to the line of sight upon holding the personal computer  10  which is in the tablet mode, the displayed image on the display screen  31  has the orientation thereof rotated 90 degrees from the open state illustrated in  FIG. 1 . That is, in the tablet mode, information is displayed on the display screen  31  with a direction perpendicular to the rotational axis of the display unit  30  as the up-and-down direction. 
         [0033]      FIG. 5  is illustrates an example internal configuration the personal computer  10 . As illustrated in  FIG. 5 , the personal computer  10  includes a CPU  101 , a main memory  102 , a hard disk drive  103 , a display mechanism  104 , an input device  106 , a small recording media drive  108 , a CD/DVD drive  109 , an input interface  105 , an output interface  110 , a fingerprint sensor  33  illustrated in  FIG. 1  and the like. These various elements may be interconnected via bus  111 . The CPU  101  executes various programs. In the main memory  102  are developed programs read from the hard disk drive  103  for execution by the CPU  101 . The hard disk drive  103  stores various programs, data and the like. The display mechanism  104  conducts processes relating to displaying information. The input device  106  includes the keyboard  21 , the track pad  22  and the like. The small recording media drive  108  accesses a small recording medium  200  loaded therein. The CD/DVD drive  109  accesses a CD-ROM  201  or DVD loaded therein. The input interface  105  inputs data from external devices. The output interface  110  outputs data to external devices. The antenna  400  transmits and receives radio waves. The wireless interface  111  performs wireless communication using the antenna  400 . The display mechanism  104  is comprised of a display controller  1041 , a display  1042  and a digitizer  1043 . The display controller  1041  controls the direction and the like of information displayed on the display screen  31  illustrated in  FIG. 1 . The display  1042  displays information on the display screen  31 . The digitizer  1043  is mounted on the back side of the display screen  31  and detects the position indicated by a stylus. The CPU  101  is an example of a processing unit. The display controller  1041  is an example of a display control unit. 
         [0034]    The personal computer  10  of an example embodiment prevents intrusion of foreign matter from the outlet  27  illustrated in  FIG. 2  while at the same time efficiently radiating heat generated by the CPU  101  and the like. 
         [0035]      FIG. 6  illustrates the internal configuration of the main body unit  20 . The main body unit  20  accommodates various components in a housing  20   a.  The housing  20   a  may include a circuit board on which electronic components  500  are mounted. The electronic components  500  include the CPU  101  illustrated in  FIG. 5  (not illustrated in  FIG. 6  since it is under a heat sink  300 ). The heat sink  300  extends over the plurality of electronic components  500  to the outlet  27 . A fan  400  is arranged nearer the outlet  27  than the various electronic components  500  are. The fan  400  discharges air to the outlet  27 . The electronic components  500  is an example of heat generating components. 
         [0036]      FIG. 7  illustrates the heat sink  300   FIG. 7  shows the side of the heat sink  300  opposite the side illustrated in  FIG. 6 . The heat sink  300  may include a plurality of fins  320   a  in the form of thin plates arrayed in parallel. The heat sink  300  includes of a heat radiating member  320 , a heat conducting member  310  and a heat pipe. The heat radiating member  320  is arranged facing the outlet  27 . The heat conducting member  310  contacts the electronic components  500  to absorb heat generated by the electronic components  500 , and conducts the heat to the heat radiating member  320 . The heat pipe extends from the heat radiating member  320  to the heat conducting member  310 . The heat radiating member  320  may include a flow path  323  for air from the fan  400  formed by the spaces between each of the plurality of fins  320   a.  The heat radiating member  320  may include an air inlet  321  facing the fan  400  and an air flow exit  322  facing the outlet  27  respectively formed by the plurality of fins  320   a  which are arrayed 
         [0037]    Heat generated by the plurality of electronic components  500  illustrated in  FIG. 6  is absorbed by the heat conducting member  310  and conducted to the heat radiating member  320 . The heat conducting member  310  may include a broad surface. The plurality of electronic components  500  includes electronic components which generate large amounts of heat such as the CPU  101 , for example. The heat conducting member  310  is in close contact with the electronic components which generate large amounts of heat. The air inlet  321  of the heat radiating member  320  faces the fan  400 . Air from the fan  400  flows from the air inlet  321  of the heat radiating member  320  into the flow path  323  and, after absorbing the heat conducted to the plurality of fins  320   a,  flows out from the air flow exit  322  to be discharged from the outlet  27 . In an example embodiment, since a heat sink  300  contacts a plurality of electronic components  500 , heat generated from the plurality of electronic components  500  can be efficiently radiated without increasing the size of the device. 
         [0038]      FIG. 8  illustrates the relationship between the flow path  323  of the heat radiating member  320  and the outlet  27 . As illustrated in  FIG. 8 , the plurality of fins  320   a  in the heat radiating member  320  of the heat sink  300  are provided extending upward in the thickness direction of the main body unit  20  and arrayed. On the other hand, the slits  27   a  provided in the outlet  27  are formed to be oblique with respect to the thickness direction of the main body unit  20 . Therefore, upon the heat radiating member  320  of the heat sink  300  is arranged facing the outlet  27 , the flow path  323  of the heat radiating member  320  is divided by the slit  27   a  of the outlet  27 . 
         [0039]      FIG. 9  is an enlarged view around the outlet  27  of the main body unit  20  with the heat sink  300 . As illustrated in  FIG. 9 , the flow path  323  formed by the fins  320   a  of the heat sink  300  is divided by the slit  27   a.  This can prevent a malfunction in which a failure of the personal computer is caused by foreign matter such as trash entering from the outlet  27 , an accident in which a screwdriver or the like is inserted from the outlet  27  to short-circuit the electronic component  500 , and so on. The example embodiment is designed so that the pitch width W 1  of adjacent fins  320   a  is smaller than the width W 2  of the slit  27   a.  As a result, the hot air having gone through the flow path  323  is efficiently discharged from the outlet  27 . Moreover, an example embodiment prevents intrusion of foreign matter entering from the outlet  27 . Therefore, the pitch width W 1  of the fins  320   a  of the heat sink  300  does not need to be too narrow. In this way, an example embodiment prevents the problem that dust caught by the fan  400  clogs the air inlet  321  of the heat radiating member  320  to lower the efficiency of the heat radiation. 
         [0040]    An example embodiment may include a conventional heat sink  300 . But, the shape of the slit  27   a  of the outlet  27  provided in the main body unit  20  may differ from a conventional one. The heat sink  300  may include a metal of high heat conductivity, which is difficult to work with compared to plastic or the like composing the housing  20   a  of the main body unit  20 . In an example embodiment, the shape of the slit  27   a  of the outlet  27  is changed to adjust the relative relationship between the flow path  323  and the slit  27   a.  As a result, an example embodiment readily achieves both of prevention of foreign matter intrusion and maintenance of heat radiation efficiency without major changes in manufacturing processes. 
         [0041]    Although the above example embodiment illustrates an example in which the housing is provided with an outlet in which slits are arrayed, the air outlet may be one in which a plurality of round through-holes are arrayed and divide the air flow path of the heat sink. 
         [0042]    Although the above example embodiment illustrates as an electronic device a tablet-type personal computer, the device may be a personal computer not including the tablet function or may be an electronic organizer or the like. 
         [0043]    Further, according to an aspect of the embodiments, any combinations of the described features, functions and/or operations can be provided. 
         [0044]    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.