Abstract:
According to an enclosure for electric equipment of an aspect of the present invention, the enclosure having the plurality of accommodation portions accommodating separate contents, respectively, can be formed by one molding without assembling a plurality of components, which can reduce the number of assembling processes. Also, formation by one component eliminates a gap which would be generated by assembling components, which can improve enclosure strength and designability and reduce manufacturing costs.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to an enclosure for electronic equipment and an imaging device and particularly to an enclosure for electronic equipment and an imaging device formed by extrusion molding. 
         [0003]    2. Description of the Related Art 
         [0004]    As an enclosure using a member made by extrusion molding, the following arts are disclosed. 
         [0005]    Japanese Patent Application Laid-Open No. 2005-45025 proposes an enclosure formed in a box shape by an extrusion molding member and a press molding member. 
         [0006]    Japanese Patent Application Laid-Open No. 5-243751 proposes an enclosure in which an end plate is mounted at both ends of a member formed in a cylindrical shape through a packing. 
         [0007]    Japanese Patent Application Laid-Open No. 9-27682 proposes an enclosure in which a plurality of members incorporating components are inserted and fitted inside a cylindrical member formed by extrusion molding. 
       SUMMARY OF THE INVENTION 
       [0008]    The enclosure of Japanese Patent Application Laid-Open No. 2005-45025 is formed by extrusion molding, but since a box-shaped enclosure is made by combining plate-state members, there is a problem that assembling performance is poor. Also, a joint between the members is seen from outside, which has a problem of lack in designability. 
         [0009]    The enclosure of Japanese Patent Application Laid-Open No. 5-243751 has a structure in which only one rectangular cavity is formed inside the cylindrical member, and in order to incorporate a component inside, a member incorporating the component should be further assembled, which has a problem of poor assembling performance. 
         [0010]    The enclosure of Japanese Patent Application Laid-Open No. 9-27682 incorporates a plurality of members incorporating components inside the cylindrical member extrusion-molded, which also has a problem of poor assembling performance similarly to the enclosure described in Japanese Patent Application Laid-Open No. 5-243751. 
         [0011]    The present invention has been made in view of the above circumstances and has an object to provide an enclosure for electronic equipment by extrusion molding which is excellent in assembling performance and heat transfer property and can ensure required strength without increasing the number of parts. 
         [0012]    In order to achieve the above object, a first aspect of the present invention provides an enclosure for electronic equipment, comprising: an enclosure body which is made of a metal and formed in a cylindrical shape; and a partition wall which partitions inside of the enclosure body, wherein the enclosure body and the partition wall are formed by extrusion molding, and two or more accommodation portions accommodating contents of electronic equipment are formed inside the enclosure body by the partition wall. 
         [0013]    According to the enclosure for electronic equipment according to the first aspect, the cylindrical metal enclosure for electronic equipment in which two or more accommodation portions for accommodating the contents of the electronic equipment are formed by the partition wall dividing the inside of the cylindrical enclosure body is formed by extrusion molding. As a result, the enclosure having a plurality of accommodation portions accommodating separate contents, respectively, can be formed by one molding without assembling a plurality of components, which can reduce the number of assembling processes. Also, formation by one component eliminates a gap which would be generated by assembling components, which can improve enclosure strength and designability and reduce manufacturing costs. 
         [0014]    The enclosure for electronic equipment according to a second aspect is characterized in that in the enclosure for electronic equipment according to the first aspect, a space as an insulating layer is formed by the partition wall between the two accommodation portions partitioned by the partition wall. 
         [0015]    According to the enclosure for electronic equipment according to the second aspect, a space as an insulating layer formed by the partition wall is formed between the two accommodation portions partitioned by the partition wall. As a result, such structure can be realized that heat generated by electronic components such as an image pickup element, IC and the like hardly affect components accommodated in other accommodation portions. Also, since the heat generated in the electronic components such as the image pickup element, IC and the like is not directly transferred to other electronic components, occurrence of nonconformity in the electronic components such as the image pickup element, IC and the like caused by the heat generated in the other electronic components can be prevented. 
         [0016]    The enclosure for electronic equipment according to a third aspect is characterized in that an insulating sheet is inserted into the space in the enclosure for electronic equipment according to the second aspect. 
         [0017]    According to the enclosure for electronic equipment according to the third aspect, the insulating sheet is inserted into the space as the insulating layer formed by the partition wall. As a result, insulating effect is further improved, and influence by heat can be further reduced. 
         [0018]    The enclosure for electronic equipment according to a fourth aspect is characterized in that in the enclosure for electronic equipment according to any one of the first to third aspects, after extrusion molding of the enclosure, an insertion hole of an image pickup lens unit is formed on an exterior portion of the enclosure and a mounting hole of the image pickup lens unit is formed on at least one of the exterior portion and the partition wall of the enclosure by secondary mechanical machining. 
         [0019]    According to the enclosure for electronic equipment according to the fourth aspect, after the extrusion molding of the enclosure, the insertion hole of the image pickup lens unit is formed by secondary mechanical machining on the exterior portion of the enclosure, and the mounting hole of the image pickup lens unit is formed by the secondary mechanical machining on at least one of the exterior portion and the partition wall of the enclosure. As a result, a lens unit can be mounted onto the enclosure. Also, by forming the mounting hole on the exterior portion and the partition wall, mounting accuracy of the lens unit to the enclosure can be improved, and strength against drop impact of a mounting portion can be enhanced. 
         [0020]    An imaging device according to a fifth aspect comprises: an enclosure for electronic equipment according to the fourth aspect; and an image pickup lens unit including an image pickup element, and the imaging device is characterized in that the image pickup element is brought into contact with the partition wall directly or through a heat transfer member when the lens unit is positioned and fixed on the enclosure. 
         [0021]    According to the imaging device according to the fifth aspect, the lens unit is mounted so that that image pickup element is brought into contact with the partition wall directly or through the heat transfer member when the lens unit is positioned and fixed. As a result, heat generated at the image pickup element can be efficiently radiated. 
         [0022]    The imaging device according to a sixth aspect comprises: an enclosure for electronic equipment according to any one of the first to fourth aspects, and the imaging device is characterized in that an image pickup lens unit is disposed at one of the two accommodation portions partitioned by the partition wall of the enclosure, while a board is disposed at the other accommodation portion. 
         [0023]    The imaging device according to a seventh aspect is characterized in that in the imaging device according to the sixth aspect, the board is guided by right and left or upper and lower grooves formed inside the other accommodation portion and accommodated in the other accommodation portion and fixed by a fixing device provided at the enclosure. 
         [0024]    According to the imaging device according to the seventh aspect, the board is guided in the groove in the horizontal or vertical direction and accommodated, by which the board is positioned in the accommodation portion and fixed to the enclosure. As a result, the number of components required for mounting of the board can be reduced. 
         [0025]    The imaging device according to an eighth aspect is characterized in that in the imaging device according to the sixth or seventh aspect, electronic component is mounted on the board, and the electronic component is brought into contact with at least one of the exterior portion and the partition wall directly or through a heat transfer member at fixation by the fixing device. 
         [0026]    According to the imaging device according to the eighth aspect, the board is fixed to the enclosure by the fixing device so that the electronic component mounted on the board is brought into contact with at least one of the exterior portion and the partition wall directly or through the heat transfer member. As a result, heat generated at the electronic component can be efficiently radiated. 
         [0027]    The imaging device according to a ninth aspect is characterized in that in the imaging device according to any one of the sixth to eighth aspects, the board has a pattern for reference potential formed thereon and the pattern for reference potential is brought into contact with at least one of the exterior portion and the partition wall at fixation by the fixing device. 
         [0028]    According to the imaging device according to the ninth aspect, the board is fixed to the enclosure by the fixing device so that the pattern for reference potential formed on the board is brought into contact with at least one of the exterior portion and the partition wall. As a result, the enclosure can be used as a ground, which can improve strength against static electricity. 
         [0029]    The imaging device according to a tenth aspect is characterized in that in the imaging device according to any one of the fifth to ninth aspects, an accommodation portion substantially in the shape of L in which a battery provided with an inverse-insertion prevention shape is accommodated is further provided. 
         [0030]    According to the imaging device according to the tenth aspect, the accommodation portion substantially in the L-shape used as a battery accommodation portion is formed. As a result, without increasing the number of processes in a machining process and the assembling process or without increasing the number of components, the battery accommodation portion having an effect to prevent inverse insertion can be formed. Also, the inverse insertion of a battery can be prevented by the substantial L-shape. 
         [0031]    According to the present invention, an enclosure for electronic equipment which is excellent in assembling performance and heat transfer property and can ensure required strength can be provided by extrusion molding without increasing the number of components. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0032]      FIG. 1A  is a perspective view of a digital camera  10  using a digital camera enclosure  1  of a first embodiment to which the present invention is applied, and  FIG. 1B  is a perspective view of a digital camera enclosure  1 ; 
           [0033]      FIG. 2  is a sectional view of an essential part of the digital camera  10  using the digital camera enclosure  1 ; 
           [0034]      FIG. 3  is another example of the first embodiment; 
           [0035]      FIG. 4  is another example of the first embodiment; 
           [0036]      FIG. 5  is a sectional view of an essential part of a digital camera enclosure  1 ′ of a second embodiment to which the present invention is applied; 
           [0037]      FIG. 6A  is a sectional view of an essential part of a digital camera enclosure  1 ″ of a third embodiment to which the present invention is applied,  FIG. 6B  is a front view of the essential part, and  FIG. 6C  is a front view of a lens barrel  5 ″ of the third embodiment; 
           [0038]      FIG. 7  is a sectional view of an essential part of a digital camera enclosure  1 ′″ of a fourth embodiment to which the present invention is applied; and 
           [0039]      FIG. 8  is a perspective view of a board  6 ′ of the fourth embodiment. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     First Embodiment 
       [0040]      FIG. 1A  is a perspective view of a digital camera  10  using a digital camera enclosure  1  according to a first embodiment of the present invention, and  FIG. 1B  is a perspective view of the digital camera enclosure  1 .  FIG. 2  is a perspective view of an essential part of the digital camera  10  using the digital camera enclosure  1 . 
         [0041]    The digital camera  10  mainly comprises the digital camera enclosure  1 , an upper plate  2 , a lower plate  3 , a strap mounting member  4 , and a lens barrel  5 . 
         [0042]    The digital camera enclosure  1  is formed of aluminum alloy and molded by extrusion molding by extrusion in the vertical direction of the enclosure (vertical extrusion). As the aluminum alloy used in the digital camera enclosure  1 , Al—Mg—Si A6063, Al—Mn A3003, A3004 and the like excellent in extrusion performance, corrosion resistance and surface treatment performance can be used, considering strength, moldability, cost and the like. Various metal materials including magnesium alloy, stainless and the like may be used as the material of the digital camera enclosure  1 . 
         [0043]    The strap mounting member  4  is constituted by a substantially T-shaped portion  4   a  with the same length as the digital camera enclosure  1  and a hole portion  4   b  through which a strap shorter than the substantially T-shaped portion  4   a  is passed. 
         [0044]    In a lens barrel  5 , a lens group is mainly disposed inside and an image pickup element  51  is disposed on a rear face. On the rear face of the image pickup element  51 , a flexible board, not shown, is disposed and connected to a board  6  through a section of an upper face or a lower face of the digital camera enclosure  1 . As a result, image data obtained by the image pickup element  51  is transmitted to a CPU mounted on the board  6 . 
         [0045]    On the board  6 , electronic components such as IC are mounted, and on a region at least in contact with an electronic component accommodation portion  12  on the front face side of the board  6 , an exposed ground pattern (pattern for reference potential) is formed. The ground pattern is formed so that its area becomes as large as possible. Also, on the board  6 , a hole through which a screw mounting the board  6  onto the digital camera enclosure  1  penetrates is formed. 
         [0046]    After components such as the strap mounting member  4 , the lens barrel  5 , the board  6  and the like are mounted at a through hole (details will be described later) formed by extrusion molding inside the digital camera enclosure  1 , the upper plate  2  and the lower plate  3  are mounted onto the digital camera enclosure  1  so as to assemble the digital camera  10 . 
       [Structure of Digital Camera Enclosure  1 ] 
       [0047]    The digital camera enclosure  1  is a substantially rectangular cylindrical member having a projecting shape to be gripped by a user provided at a part on the front face side. Inside the digital camera enclosure  1 , an optical system accommodation portion  11 , an electronic component accommodation portion  12 , an insulating layer  13 , and a battery accommodation portion  17 , which are through holes formed by vertical extrusion, are formed. Also, on an outer edge of the digital camera enclosure  1 , a recess portion  14  for strap mounting member in an undercut shape formed by extrusion molding, a lens barrel mounting portion  15 , a board mounting portion  16  and the like are formed. 
         [0048]    The optical system accommodation portion  11  is a substantially rectangular through hole provided on the front face side of the digital camera enclosure  1  and formed at the same time when the outer shape of the digital camera enclosure  1  is formed by extrusion molding. Inside the optical system accommodation portion  11 , a lens barrel  5  is mounted through the lens barrel mounting portion  15  provided on the front face side of the optical system accommodation portion  11 . 
         [0049]    The electronic component accommodation portion  12  is a substantially rectangular through hole provided on a rear face side of the digital camera enclosure  1  and having a projection portions in the right and left directions and is formed at the same time when the outer shape of the digital camera enclosure  1  is formed by extrusion molding. Inside the electronic component accommodation portion  12 , through the board mounting portion  16  provided on the rear face side of the electronic component accommodation portion  12 , the board  6  on which the electronic component such IC is mounted is accommodated. Projection portions  12   a  provided right and left of the electronic component accommodation portion  12  are used as positioning portions of the board  6  in the horizontal direction. 
         [0050]    The insulating layer  13  is a center part of the digital camera enclosure  1  and is a substantially rectangular through hole formed between the optical system accommodation portion  11  and the electronic component accommodation portion  12  and formed at the same time when the outer shape of the digital camera enclosure  1  is formed by extrusion molding. The insulating layer  13  is formed so that there is no spot where the optical system accommodation portion  11  is adjacent to the electronic component accommodation portion  12 . As a result, heat generated at the optical system accommodation portion  11  or the electronic component accommodation portion  12  is shielded by the insulating layer  13  and not directly transferred to the other accommodation portions. 
         [0051]    The recess portion  14  for strap mounting member is a recess portion substantially in the T-shape formed on an outer edge of the digital camera enclosure  1  and is formed at the same time when the outer shape of the digital camera enclosure  1  is formed by extrusion molding. 
         [0052]    The lens barrel mounting portion  15  is formed by post machining on a wall on the front face side of the optical system accommodation portion  11  of the digital camera enclosure  1  and constituted by a hole  15   a  having a diameter larger than the maximum diameter of the lens barrel  5  and four screw holes  15   b  formed around the hole  15   a  and used when the lens barrel  5  is fixed to the digital camera enclosure  1 . It is only necessary that the number of the screw holes  15   b  may be three or more and not limited to four. 
         [0053]    The board mounting portion  16  is formed by post machining and is constituted by four holes  16   a  formed on a wall of the rear face side of the electronic component accommodation portion  12  and four screw holes  16   b  formed integrally with the holes  16   a  and formed on a wall on the front face side of the electronic component accommodation portion  12  (wall between the electronic component accommodation portion  12  and the insulating layer  13 ). The number of the holes  16   a  and the screw holes  16   b  is not limited to 4 as with the screw holes  15   b.    
         [0054]    The battery accommodation portion  17  is substantially L-shaped through hole provided inside the projection portion on the front face of the digital camera enclosure  1  and is formed at the same time when the outer shape of the digital camera enclosure  1  is formed by extrusion molding. A substantially L-shaped battery  7  substantially the same as the battery accommodation portion  17  can be inserted inside in a predetermined direction but can not be inserted in an opposite direction, by which inverse insertion of a battery is prevented. 
       [Manufacturing Method of the Digital Camera Enclosure  1 ] 
       [0055]    First, by extruding aluminum alloy from a die (not shown) using an extruding machine (not shown), a hollow cylindrical rod material having a sectional shape shown in  FIG. 1B  is molded. By cutting the substantially rectangular hollow cylindrical rod material obtained as such to a predetermined length by a disc saw and the like, the digital camera enclosure  1  provided with the optical system accommodation portion  11 , the electronic component accommodation portion  12 , the insulating layer  13 , the recess portion  14  for strap mounting member, and the battery accommodation portion  17  is formed. 
         [0056]    Next, by mechanical machining, the lens barrel mounting portion  15  is formed on the front face of the digital camera enclosure  1 . The digital camera enclosure  1  formed by extrusion molding is placed on a machining center and the like with the front face up, and hole making is performed from the front face side. After that, by performing deburring, screw cutting (screw holes  15   b ) and the like, the lens barrel mounting portion  15  is formed. 
         [0057]    Lastly, by mechanical machining, the board mounting portion  16  is formed on the rear face of the digital camera enclosure  1 . The digital camera enclosure  1  formed by extrusion molding is placed on the machining center and the like with the rear face up, the hole making and screw cutting are performed from the rear face side. After that, deburring and the like is performed and the hole  16   a  and the screw hole  16   b  are formed. 
       [Mounting of Components on Each Accommodation Portion of the Digital Camera Enclosure  1 ] 
       [0058]    Using  FIG. 2 , mounting of components onto the optical system accommodation portion  11 , the electronic component accommodation portion  12 , and the recess portion  14  for strap mounting member will be described. 
       (Mounting of the Lens Barrel  5  on the Optical System Accommodation Portion  11 ) 
       [0059]    The lens barrel  5  with a mounting member  52  mounted on the outer edge is made to penetrate through the hole  15   a  of the lens barrel mounting portion  15 . And a screw  53  is inserted through the hole of the mounting member  52  and screwed and fitted in the screw hole  15   b  so that the image pickup element  51  and a flexible board (not shown) disposed on its rear face and the wall on the rear face side of the optical system accommodation portion  11  are in contact with each other through a heat transfer member  21 . As a result, the lens barrel  5  is mounted on the digital camera enclosure  1 . 
         [0060]    The heat generated at the image pickup element  51  is directly transferred to the digital camera enclosure  1  through the heat transfer member  21 . The heat transferred to the digital camera enclosure  1  is transferred through inside the digital camera enclosure  1  and radiated to the outside of the digital camera enclosure  1  (See the arrow in  FIG. 2 ). Since the insulating layer  13  is provided adjacently to the optical system accommodation portion  11 , the heat transferred to the digital camera enclosure  1  is shielded by the insulating layer  13  and is not directly transferred to the board  6  disposed in contact with the inside of the electronic component accommodation portion  12 . As a result, influence of the heat generated at the image pickup element  51  on the electronic component mounted on the board  6  can be reduced. 
       (Mounting of the Board  6  on the Electronic Component Accommodation Portion  12 ) 
       [0061]    A projection portion (not shown) is provided at a part of both the right and left ends of the board  6 , and the board  6  and the electronic component accommodation portion  12  are formed in a dimensional relation so that the projection portion of the board  6  and the projection portion  12   a  of the electronic component accommodation portion  12  are in contact with each other. In a state where the board  6  is positioned in the horizontal direction by inserting the board  6  into the electronic component accommodation portion  12  so that the projection portion  12   a  of the electronic component accommodation portion  12  and the board  6  are in contact with each other, a screw  62  is inserted through the hole of the board  6  and the hole  16   a  of the board mounting portion  16  so as to be screwed and fitted in the screw hole  16   b,  the board  6  is mounted inside the electronic component accommodation portion  12 . 
         [0062]    An elastic body is disposed on the rear face of the board  6 , and the board  6  is threadably mounted so that the ground pattern provided on the front face side of the board  6  and the electronic component accommodation portion  12  are brought into contact with each other with a contact pressure of a predetermined pressure or more. As a result, the metal digital camera enclosure  1  can be used as a ground, which can improve strength against static electricity. 
         [0063]    Also, the board  6  is threadably mounted so that a desired electronic component  61  mounted on the board  6  and the wall on the rear face side of the electronic component accommodation portion  12  are brought into contact through a heat transfer member  22 . The heat generated at the electronic component  61  is transferred directly to the digital camera enclosure  1  through the heat transfer member  22 . The heat transferred to the digital camera enclosure  1  is transferred through inside the digital camera enclosure  1  and radiated to the outside of the digital camera enclosure  1  (See the arrow in  FIG. 2 ). Also, since the insulating layer  13  is provided adjacently to the electronic component accommodation portion  12 , the heat transferred to the digital camera enclosure  1  is shielded by the insulating layer  13  and is not directly transferred to the image pickup element  51  disposed in contact with the optical system accommodation portion  11 . As a result, the influence of the heat generated at the electronic component mounted on the board  6  on the image pickup element  51  can be reduced. 
       (Mounting of the Strap Mounting Member  4  on the Recess Portion  14  for Strap Mounting Member) 
       [0064]    The substantially T-shaped portion  4   a  of the strap mounting member  4  is inserted into the recess portion  14  for strap mounting member. By sandwiching the strap mounting member  4  between the upper plate  2  and the lower plate  3 , only the hole portion  4   b  into which the strap is to be inserted is exposed to the outside of the digital camera enclosure  1 . 
         [0065]    According to this embodiment, since the digital camera enclosure having a plurality of accommodation portions inside can be formed by single molding, manufacturing costs of parts and the number of assembling processes can be reduced. Also, since the digital camera enclosure is formed by a single part, a gap generated on a side face and the like due to assembling of parts is eliminated, and enclosure strength and designability can be improved. 
         [0066]    In the present embodiment, by providing an air layer between the optical system accommodation portion  11  and the electronic component accommodation portion  12  by the insulating layer  13 , flow of heat from the optical system accommodation portion  11  to the electronic component accommodation portion  12  and the flow of heat from the electronic component accommodation portion  12  to the optical system accommodation portion  11  are shielded, but by inserting an insulating sheet in the insulating layer  13 , heat insulation effect of the insulating layer  13  can be further improved, and influence of heat can be further reduced. 
         [0067]    Also, in the present invention, the heat transfer member is sandwiched only at one spot between the electronic component on the rear face side of the board  6  and the electronic component accommodation portion  12 , but a plurality of heat transfer members may be used or the heat transfer member may be used on the whole faces on the both sides of the board as long as no nonconformity is caused in the electronic component and the like by application of a force on the board  6 . 
         [0068]    Also, in the present embodiment, the digital camera enclosure is made using a body portion formed by extrusion molding as it is, but in order to handle various designs or to improve radiation effect, secondary machining such as resin painting on the outer edge may be performed. 
         [0069]    Also, in the present embodiment, the digital camera enclosure with a sectional shape in which the optical system accommodation portion  11  and the electronic component accommodation portion  12  are separated is used, but as shown in  FIG. 3 , the optical system accommodation portion  11  and the electronic component accommodation portion  12  may be partially connected. By this arrangement, the image pickup element  51  and the board  6  can be connected by a flexible board  8  more easily, which facilitates assembling. 
         [0070]    Also, in the present embodiment, the optical system accommodation portion  11  and the electronic component accommodation portion  12  are separated from each other, and the insulating layer  13  is formed between the optical system accommodation portion  11  and the electronic component accommodation portion  12 , but the insulating layer  13  does not have to be formed. Also, the optical system accommodation portion  11  and the electronic component accommodation portion  12  may be fully separated by a partition wall dividing the optical system accommodation portion  11  from the electronic component accommodation portion  12 , or as shown in  FIG. 4 , one end of the partition wall may be connected to an outer wall of the digital camera enclosure. In this case, flexure of the partition wall on which the lens barrel  5  is mounted can make resistance against impact such as drop stronger. 
         [0071]    Also, in the present embodiment, the digital camera enclosure is formed by vertical extrusion, but the extrusion direction is not limited to that. In the case of horizontal extrusion, the board  6  is positioned in the vertical direction with respect to the electronic component accommodation portion  12 . 
       Second Embodiment 
       [0072]    A second embodiment is different from the first embodiment in mounting of the lens barrel, in which a decoration ring is used. 
         [0073]      FIG. 5  is a partial sectional view of a digital camera enclosure  1 ′ of the second embodiment. The same reference numerals are given to the same portions as those in the first embodiment, and the description will be omitted. 
       [Structure of the Digital Camera Enclosure  1 ′] 
       [0074]    A lens barrel mounting portion  15 ′ is formed by post machining on the wall on the front face side of the optical system accommodation portion  11  and constituted by a hole  15   a ′ having a diameter larger than the maximum diameter of the lens barrel  5 ′ and four screw holes  15   b ′ formed by post machining on the wall on the rear face side of the optical system accommodation portion  11  and used when the lens barrel  5  is fixed to the digital camera enclosure  1 ′. It is only necessary that the number of the screw holes  15   b ′ may be three or more and not limited to four. 
       [Mounting of Components on Each Accommodation Portion of the Digital Camera Enclosure  1 ′] 
     (Mounting of the Lens Barrel  5 ′ on the Optical System Accommodation Portion  11 ) 
       [0075]    The lens barrel  5 ′ on which the mounting member  53  is mounted on the outer edge is penetrated through the hole  15   a ′ of the lens barrel mounting portion  15 ′. A screw  54  is inserted through the hole of the mounting member  53  and screwed and fitted in the screw hole  15   b ′ so that the image pickup element  51  and the flexible board  8  disposed on its rear face and the wall on the rear face side of the optical system accommodation portion  11  are brought into contact with each other through the heat transfer member  21 . As a result, the lens barrel  5 ′ is mounted on the digital camera enclosure  1 ′. The heat generated at the image pickup element  51  is transferred to the digital camera enclosure  1 ′ efficiently. 
         [0076]    Next, a decoration ring  55  is attached to the digital camera enclosure  1 ′. The decoration ring  55  comprises an attachment portion  55   a  to be fitted in the hole  15   a ′ and a decoration portion  55   b  covering the hole  15   a ′ at attachment. At the center of the decoration ring  55 , a hole into which the lens barrel  5 ′ can be inserted is formed. The lens barrel  5 ′ is fitted through the hole formed at the center of the decoration ring, the attachment portion  55   a  is fitted through the hole  15   a ′, and the decoration ring  55  is attached to the digital camera enclosure  1 ′ using snap fit and the like, not shown. 
         [0077]    According to the present embodiment, since the screw used for mounting of the lens barrel is hidden by the decoration ring, the heat generated at the image pickup element is removed efficiently, while the designability can be improved. 
       Third Embodiment 
       [0078]    A third embodiment is different from the first and second embodiments in mounting of the lens barrel, in which mounting accuracy and mounting strength of the lens barrel are improved as compared with those in the first embodiment. 
         [0079]      FIG. 6A  is a partial sectional view of a digital camera enclosure  1 ″ of the third embodiment,  FIG. 6B  is a front view of a lens barrel mounting portion  15 ″, and  FIG. 6C  is a front view of a lens barrel  5 ″. The same reference numerals are given to the same portions as those in the first embodiment, and the description will be omitted. 
       [Structure of the Digital Camera Enclosure  1 ″] 
       [0080]    The lens barrel mounting portion  15 ″ is formed by post machining and constituted by a hole  15   a ″ into which a body portion of the lens barrel  5 ″ can be fitted and screw holes  15   b ″ and  15   c ″ used when the lens barrel  5 ″ is fixed on the digital camera enclosure  1 ″. 
         [0081]    The hole  15   a ″ is formed on the wall on the front face side of the optical system accommodation portion  11 , and is constituted by, as shown in  FIG. 6B , a hole  15   a ″- 1  having a diameter larger than the maximum diameter of the lens barrel  5 ″ and four projection-shaped holes  15   a ″- 2  integrally formed with the hole  15   a ″- 1  and arranged uniformly on an outer circumference of the hole  15   a ″- 1 . 
         [0082]    The holes  15   b ″ are four screw holes formed by post machining on the wall on the front face side of the optical system accommodation portion  11  and formed at positions displaced by a predetermined angle with respect to the hole  15   a ″- 2  when seen from the front face of the digital camera enclosure  1 ″. 
         [0083]    The holes  15   c ″ are four screw holes formed by post machining on the wall on the rear face side of the optical system accommodation portion  11  and formed at the same positions as those of the holes  15   a ″- 2  when seen from the front face of the digital camera enclosure  1 ″. 
         [0084]    It is only necessary that the number of the screw holes  15   b ″ and  15   c ″ is three or more and not limited to four. 
       [Mounting of Components on Each Accommodation Portion of the Digital Camera Enclosure  1 ″] 
     (Mounting of the Lens Barrel  5 ″ on the Optical System Accommodation Portion  11 ) 
       [0085]    First, when the lens barrel  5 ″ is mounted on the digital camera enclosure  1 ″, mounting rings  56  and  57  are disposed on the lens barrel  5 ″ so that the mounting rings  56  are located on the front face of the wall on the rear face side of the optical system accommodation portion  11  and the mounting rings  57  are located on the front face of the wall on the front face side of the optical system accommodation portion  11 . 
         [0086]    Next, the mounting rings  56  are penetrated through the holes  15   a ″- 2  and the lens barrel  5 ″ is penetrated through the hole  15   a ″- 1 . A screw  58  is inserted through the hole of the mounting ring  56  and screwed and fitted in the screw holes  15   b ″. The screw  58  is also inserted through the hole of the mounting ring  57  and screwed and fitted in the screw holes  15   c ″. 
         [0087]    Lastly, the decoration ring  59  is attached to the digital camera enclosure  1 ′. The lens barrel  5 ″ is fitted through the hole formed at the center part of a decoration ring  59 , and the decoration ring  59  is attached to the digital camera enclosure  1 ′ using snap fit or the like, not shown. 
         [0088]    According to the present embodiment, since the screw used for mounting of the lens barrel is hidden by the decoration ring, the heat generated at the image pickup element can be efficiently removed and designability can be improved. Also, since the mounting portions are provided at two locations in the axial direction of the lens barrel, the mounting accuracy of the lens barrel in the inclination direction can be improved. Also, by mounting at plural locations, the mounting strength of the lens barrel  5 ″ can be improved, and resistance against impact such as drop can be enhanced. 
       Fourth Embodiment 
       [0089]    A fourth embodiment is different from the first embodiment in the shape of the electronic component accommodation portion and has an object to further improve the heat removal effect. 
         [0090]      FIG. 7  is a partial sectional view of a digital camera enclosure  1 ′″ of the fourth embodiment, and  FIG. 8  is a perspective view of a board  6 ′ accommodated inside an electronic component accommodation portion  12 ′ of the fourth embodiment. The same reference numerals are given to the same portions as those in the first embodiment, and the description will be omitted. 
       [Structure of the Digital Camera Enclosure  1 ′″] 
       [0091]    The electronic component accommodation portion  12 ′ is a through hole provided on the rear face side of the digital camera enclosure  1 ′″ and having projection portions in the right and left directions and is formed at the same time when the outer shape of the digital camera enclosure  1 ′″ is formed by extrusion molding. Inside the electronic component accommodation portion  12 ′, the board  6 ′ on which the electronic components are mounted in the straight state in the vertical direction as shown in  FIG. 8  is accommodated through the board mounting portion  16  provided on the rear face side of the electronic component accommodation portion  12 . Projection portions  12   a ′ provided at right and left of the electronic component accommodation portion  12 ′ are used as positioning portions in the right and left directions of the board  6 ′. 
         [0092]    On the walls on the front face side and the rear face side of the electronic component accommodation portion  12 ′, a thick part is made in compliance with the shape of the board  6 ′ to be inserted inside, and a recess portion is partially formed in the shape of the electronic component accommodation portion  12 ′. As a result, a volume of the digital camera enclosure  1 ′″ and heat capacity can be increased. Also, strength of the digital camera enclosure  1 ′″ can be enhanced. Also, as compared with a case where the inside is not built up, the size of the digital camera enclosure  1 ′″ can be reduced while the same heat capacity is maintained. 
         [0093]    Projection portions (not shown) are provided at a part of both the right and left ends of the board  6 ′, and the board  6 ′ and the electronic component accommodation portion  12 ′ are formed in such a dimensional relation that the projection portion of the board  6 ′ and the projection portion  12   a ′ of the electronic component accommodation portion  12 ′ are brought into contact with each other. 
       (Mounting of the Board  6 ′ on the Electronic Component Accommodation Portion  12 ′) 
       [0094]    The board  6 ′ is inserted in the electronic component accommodation portion  12 ′ so that the projection portion  12   a ′ of the electronic component accommodation portion  12 ′ and the board  6 ′ are brought into contact with each other. While the board  6 ′ is positioned in the right and left direction, the screw  62  is inserted into the hole of the board  6 ′ and the hole  16   a  of the board mounting portion  16  and screwed and fitted in the screw hole  16   b,  and thereby the board  6 ′ is mounted inside the electronic component accommodation portion  12 ′. 
         [0095]    An elastic body is disposed on the rear face of the board  6 ′, and the board  6 ′ is threadably mounted so that the ground pattern provided on the front face side of the board  6 ′ and the electronic component accommodation portion  12 ′ are brought into contact with each other with a contact pressure of a predetermined pressure or more. As a result, the metal digital camera enclosure  1 ′″ can be used as a ground, which can improve strength against static electricity. 
         [0096]    Also, the board  6 ′ is threadably mounted so that the desired electronic component  61  mounted on the board  6 ′ and the wall on the rear face side of the electronic component accommodation portion  12 ′ are brought into contact with each other through the heat transfer member  22 . The heat generated at the electronic component  61  is transferred directly to the digital camera enclosure  1 ′″ through the heat transfer member  22 . 
         [0097]    In the present embodiment, since the ground pattern of the board  6 ′ and the electronic component accommodation portion  12 ′ are brought into contact in a large area, the ground can be taken stably. Also, by bringing the board  6 ′ and the electronic component accommodation portion  12 ′ into contact in a large area, the heat can be removed more efficiently. 
         [0098]    In the present embodiment, the ground pattern of the board  6 ′ is provided only on the front face side, but since the larger the contact area between the ground pattern of the board  6 ′ and the electronic component accommodation portion  12 ′, the better it is, it may be so configured that the ground pattern is provided also on the rear face side of the board  6 ′ so as to be brought into contact with the electronic component accommodation portion  12 ′ if there is no problem in assembling performance and the like. 
         [0099]    Also, in the present embodiment, a sectional area of the digital camera enclosure  1 ′″ and the heat capacity can be increased by building up so as to eliminate an unnecessary cavity portion. 
         [0100]    The present invention can be applied not only to the digital camera enclosure but also to various electronic components including cellular phone, PDA, music player and the like. Also, in the present invention, extrusion molding is carried out using an aluminum alloy, but not limited to aluminum, various materials capable of extrusion molding can be used. For example, a metal material such as a magnesium alloy may be used or a plastic material may be used. 
         [0101]    Also, in the present invention, the case where the shape of the enclosure is substantially rectangular is used as an example for explanation, but not limited to the substantial rectangle, various shapes can be used.