Abstract:
An electronic device that includes a cabinet having a top face, an undersurface, and a side that completely surrounds the top face and the undersurface by connecting the outer edge of the top face and the outer edge of the undersurface together; and an electronic part disposed inside the cabinet, wherein the cabinet has an exhaust hole provided in the undersurface of the cabinet, at a position distant from the side of the cabinet; a fan disposed inside the cabinet, which blows air inside the cabinet from the exhaust hole; and at least one protrusion disposed at the back of the undersurface of the cabinet, protruding from the undersurface of the cabinet and holding the cabinet placed on a flat plate in a state of being lifted.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based upon and claims the benefit of priority of the prior Japanese Patent Application No. 2008-83925, filed on Mar. 27, 2008, the entire contents of which are incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1.. Field of the Invention 
     An embodiment discussed herein is directed to an electronic device equipped with a cabinet and electronic parts disposed inside the cabinet. 
     2.. Description of the Related Art 
     Generally, electronic devices incorporate various kinds of electronic parts inside a box-shaped cabinet to realize features corresponding to the electronic devices. Some of these electronic devices incorporate electronic parts that generates heat inside the cabinet, thereby adopt a structure in which a cooling fan is provided to cool down the electronic parts and prevent the temperature inside the cabinet from becoming high with the heat generated from the electronic parts and further an exhaust hole is provided in the cabinet so that the air heated by depriving the heat from the heat-producing electronic parts can be discharged from the exhaust hole. 
     For example, a notebook type personal computer (hereinafter, abbreviated as note PC) is internally equipped with a CPU, other heat-producing electronic parts, and many various kinds of electronic parts, and has a main unit equipped with a keyboard on the top face and a display unit equipped with a display screen hinge-mounted to the main unit to open and close freely. And the main unit incorporates a fan to cool down the CPU and the other heat-producing electronic parts, and is configured to discharge air from the exhaust hole provided in the sides of the cabinet or the like of the main unit. 
     The recent trend of ever more advanced functions and miniaturization of the note PC poses a problem about the position of the exhaust hole in the cabinet of the main unit. Generally, the left and right sides of the main unit cabinet is quite packed with various kinds of parts provided thereat, for example, such as a CD/DVD mounting port, a memory card loading port, various types of connectors, and an audio jack. Also, since the sides at the back of the main unit cabinet are similarly packed and a battery for driving the note PC is often placed at the back of the main unit, and in that case, the placement of a connector or the like in the sides of the back of the cabinet can be considerably limited. Since there is an operator at the front side of the main unit cabinet, it is impossible to discharge the heated air from the sides of the front side. 
     Under such circumstances, the number of parts disposed in the sides of the cabinet tends to increase with ever more advanced features, which makes it very difficult to secure a space for forming an exhaust hole of sufficient width, since area of the sides is becoming smaller with the advancement of miniaturization and slimness. This trend is common not only in the note PCs, but also in various types of electronic devices See, for example, Japanese Laid-open Patent Publication Nos. 10-270879, 2000-227824, and 2001-345588. 
     SUMMARY OF THE INVENTION 
     According to an aspect of the invention, an electronic device includes a cabinet having a top face, an undersurface, and a side that completely surrounds the top face and the undersurface by connecting the outer edge of the top face and the outer edge of the undersurface together; and an electronic part disposed inside the cabinet, wherein the cabinet has an exhaust hole provided in the undersurface of the cabinet, at a position distant from the side of the cabinet; a fan disposed inside the cabinet, which blows air inside the cabinet from the exhaust hole; and at least one protrusion disposed at the back of the undersurface of the cabinet, protruding from the undersurface of the cabinet and holding the cabinet placed on a flat plate in a state of being lifted. 
     Additional objects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The object and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. 
     It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view illustrating the outlook of a note PC; 
         FIG. 2  is a drawing illustrating an open state of the note PC; 
         FIG. 3  is a drawing illustrating a second closed state of the note PC; 
         FIG. 4  is a drawing illustrating the left side of the note PC in the first closed state (the state illustrated in  FIG. 1 ); 
         FIG. 5  is a drawing illustrating the right side of the note PC in the first closed state (the state illustrated in  FIG. 1 ); 
         FIG. 6  is a drawing illustrating the undersurface of the note PC; 
         FIG. 7  is a cross-sectional view of the note PC; and 
         FIG. 8  is a cross-sectional perspective view of the main unit cabinet of the note PC. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     An embodiment of the present invention will be described below with reference to the accompanying drawings. 
       FIG. 1  is a perspective view of the outlook of a note PC. Here, this note PC will be explained as one embodiment of the electronic device. 
     This note PC has a main unit equipped with a keyboard on the top face and a display unit equipped with a display screen. This note PC is so-called a convertible type which has a closed state where the display unit is closed with the display screen facing the keyboard (a first closed state illustrated in  FIG. 1 ) an open state where the display unit stands with the display screen facing the front side, and further, a second closed state where the display unit is closed on the main unit with the display screen facing upward. 
       FIG. 2  is a drawing illustrating an open state of the note PC in  FIG. 1 ;  FIG. 3  is a drawing illustrating a second closed state of the note PC in  FIG. 1 ;  FIGS. 4 ,  5  are drawings illustrating the left and right sides of the note PC respectively in the first closed state (the state illustrated in  FIG. 1 ); and  FIG. 6  is a drawing of the undersurface of the note PC in  FIG. 1 . 
     A note PC  100  illustrated in these  FIGS. 1 to 6  has a main unit  200  and a display unit  300 . The display unit  300  is connected to the main unit  200  via a biaxial connecting unit  400  illustrated in  FIG. 2 , which enables opening and closing between the first closed state illustrated in  FIG. 1  and the open state illustrated in  FIG. 2  as well as rotates the display unit  300  a half-turn around an axis  401  of the connecting unit  400  in the direction indicated by the arrow R to close the display unit  300  on the main unit  200  as illustrated in the second closed state in  FIG. 3 . 
     The main unit  200  has the top face equipped with a keyboard  202 , the undersurface that is the bottom surface of this note PC, and a side that completely surrounds the top face and the undersurface by connecting the edges of the top face and the undersurface together. A main unit cabinet  201  incorporates heat-producing electronic parts such as a CPU and many other electronic parts. 
     In addition, the display unit  300  has a display unit cabinet  301  and a display screen  312 , and in the first closed state illustrated in  FIG. 1 , the display screen  302  is closed on the main unit  200  with the display screen  302  facing the keyboard  202 , while in the second closed state illustrated in  FIG. 3 , the display screen  302  is closed on the main unit  200  in such a manner that the rear surface relative to the display screen  302  of the display unit cabinet  301  faces the keyboard  202  so that the display screen  302  appears outside. 
     On the left side of the main unit cabinet  201 , as illustrated in a left side drawing in  FIG. 4 , there are disposed audio jacks  203  for microphone and headphone, an USB connector  204  complying with the USB standard, a SD card slit  205  through which a SD card as a type of memory cards is inserted, a hole  206  for security lock, an audio volume controller  207  or the like. 
     Incidentally in this  FIG. 4 , a bulge  2012  that bulges out at the back of an undersurface  2011  of the main unit cabinet  201  is illustrated, and protrusions  2013  that serve as supporter when this note PC  100  is put on the floor is also illustrated. The protrusions  2013  are provided on both sides, at the front and back of the main unit cabinet  201 , and the protrusion  2013  at the back is provided at the position overlapping the bulge  2012 . 
     Additionally, on the right side of the main unit cabinet  201 , as illustrated in a right side drawing in  FIG. 5 , there are disposed a power terminal  211 , a CF card slit  212  through which a CF card for communication is inserted, a small USB (mini USB) connector  213 , and others. 
     Also in this FIG,  5 , the bulge  2012  that bulges out at the back of the undersurface  2011  of the main unit cabinet  201  and the protrusions  2013  are illustrated as in  FIG. 4 . 
     Moreover, on the undersurface  2011  of the main unit cabinet  201 , as illustrated in a drawing of undersurface in  FIG. 6 , the above-described bulge  2012  and the protrusions  2013  are illustrated and furthermore, an exhaust hole  2014  is illustrated. 
     The bulge  2012  has a shape of extending to the left and right at the back of the main unit cabinet  201  and bulging from the undersurface. In all, four protrusions  2013  are disposed, each at the left and right of both the front and back sides respectively, wherein the two protrusions  2013  at the back are disposed in a position overlapping the bulge  2012 , each at both the left and right of the bulge  2012 . These protrusions  2013  serve to hold the undersurface  2011  in the main unit cabinet  201  of this note PC  100  in a state of being lifted from the floor when this note PC  100  is put on the top of a desk or the like. In the present embodiment, multiple protrusions are provided to be spaced out from each other, however, it is also possible to attain the same effect with one protrusion depending on shape and placement of the protrusion. 
     Moreover, the exhaust hole  2014  is formed adjacent to the bulge  2012 , at a position nearer to the front side than the bulge  2012  and is distant from any sides surrounding the main unit cabinet  201 . A guide member  2015  is provided within this exhaust hole  2014 . This guide member  2015  will be explained together with an explanation of  FIGS. 7 ,  8 . 
     As illustrated in  FIG. 6 , a cover that can be removed by taking off a screw is provided for the undersurface  2011  of the main unit cabinet  201  to enable the repair and replacement of internal parts, which however, is not the subject here and a detailed explanation is omitted. Although several parts are provided inside the cover, there is more extra space in this undersurface  2011  than in the sides and the exhaust hole  2014  of sufficient width is also formed. 
       FIG. 7  is a cross-sectional view of the note PC illustrated in  FIGS. 1 to 6 , and  FIG. 8  is a cross-sectional perspective view of the main unit cabinet of the note PC illustrated in  FIGS. 1 to 6 . 
     Both  FIG. 7  and  FIG. 8  illustrate a cross-section of the exhaust hole  2014  from the front side toward the back of the note PC  100 . 
     In a fan placement space  2016  and a battery placement space  2017  in the main unit cabinet  201  illustrated in  FIG. 8 , a fan  2018  and a battery  2019  are disposed respectively as illustrated in  FIG. 7 . 
     The bulge  2012  that bulges on the undersurface  2011  of the main unit cabinet  201  serves to secure space for disposing the battery  2019 . Additionally, with the four protrusions  2013  provided on the undersurface  2011  of the main unit cabinet  201 , the undersurface  2011  is held in a state of being lifted from a floor surface  10 . Since the protrusions  2013  at the back are placed in a position overlapping the bulges  2012 , this note PC  100  is held slightly askew to the front side when placed on the floor, which enhances the operability of the keyboard and also serves to make a space between the undersurface  2011  and the floor surface  10  wider at the back to guide the air discharged from the exhaust hole  2014  to the back. 
     In addition, the fan placement space  2016  has openings  2016   a ,  2016   b . above and below thereof. The fan  2018  disposed in this fan placement space  2016  takes in air from these openings  2016   a ,  2016   b . and discharges the air toward the back of the main unit cabinet (in the direction indicated by the arrow rl in  FIGS. 7 ,  8 ). The air discharged from the fan  2018  in the direction of arrow rl hits a guide panel  2015  formed diagonally, which guides the air in a slanting downward direction (r 2 ) and the air is discharged outside the cabinet from the exhaust hole  2014  by being directed to flow in the lower diagonal direction toward the back of the main unit cabinet  201 . The air discharged outside the cabinet flows divided into the left and right as illustrated by the arrows A, B in  FIG. 6  due to the bulges  2012  disposed immediately at the back and flows outside from the bottom of the note PC  100 . Incidentally, since there is also space between the bulges  2012  and the floor, the air discharged outside the cabinet from the exhaust hole  2014  flows through the bottom of the bulges  2012  as well to the direction indicated by the arrow C. In this way, the air discharged from the exhaust hole  2014  disperses and flows through several paths from the bottom of the note PC  100 . 
     As described above, in the note PC of the present embodiment, since the exhaust hole  2014  of sufficient width is provided on the undersurface, and the undersurface  2011  is held in a state of being lifted from the floor, especially at the back thereof, it is possible to secure flow path of sufficient width even with the exhaust hole  2014  formed on the undersurface, thereby enough cooling capability is ensured. 
     Further, since the protrusions are provided, clearance can be secured between the floor surface on which this electronic device is placed and the undersurface of the cabinet especially at the back of the electronic device, thereby flow path of the air discharged from the exhaust hole can be secured. Therefore, the electronic device of the present invention can secure a sufficient cooling capability adequate for the advancement of high functions, miniaturization, and slimness. 
     It should be noted that, although here, the explanation has been given about the note PC, the technical concept of the present invention is not limited to the note PC, but also can be applied to electronic devices in general equipped with a cooling capability by a fan. 
     All examples and conditional language recited herein are intended for pedagogical purposes to aid the reader in understanding the principles of the invention and the concepts contributed by the inventor to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions, nor does the organization of such examples in the specification relate to a showing of the superiority and inferiority of the invention. Although the embodiment of the present invention have been described in detail, it should be understood that the various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention.