Abstract:
An electronic device having a cabinet formed from two halves that are joined together have provided therein multiple boards that are stacked and housed. The joining of the cabinet halves secures the boards in position within the cabinet and assures electrical continuity between boards, such that the positioning and arrangement of the boards within the cabinet upon assembly of the cabinet is not compromised by the cabinet being moved or flipped over.

Description:
FIELD OF THE INVENTION 
     This invention concerns an electronic device that has multiple boards including a circuit board and a cabinet inside which these multiple boards are accommodated, and in particular, it concerns an assembly of boards that are stacked in a simplified and secure manner within such cabinet. 
     BACKGROUND OF THE INVENTION 
     Heretofore, entertainment devices, personal computers, and other electronic devices that employ an optical disk, such as game machines, CD and DVD players and the like, have been constituted to have a disk device that includes an optical pickup unit, a circuit board on which a CPU and image processing unit are mounted, and a cabinet made up of an upper case and lower case that houses such components. And if for example it is an entertainment device, image information and sound information recorded on an optical disk can be played by detecting it with the optical pickup unit, computation-processing it with the CPU and image processing unit, and outputting video and audio control signals to a display device, etc. 
     With such an electronic device, the playback of image information and sound information is greatly affected by the processing capacity of the CPU and image processing unit, so it is required that the processing capacity of the CPU and image processing unit be speeded up. Here, when the processing capacity of the CPU and image processing unit is speeded up, the electromagnetic waves emitted from their circuit elements become stronger, and normally measures against EMI are implemented in such electronic devices. 
     Specifically, if the cabinet is made of ABS resin, etc., anti-EMI measures are accomplished by covering the circuit board, that includes the CPU and image processing unit, with metal shielding plates and ensuring electrical continuity between these shielding plates and the grounding pattern formed on the circuit board, which means that the circuit board is housed inside the cabinet and sandwiched in between two metal shielding plates. 
     Heretofore, such an electronic device has been assembled by (1) attaching a shielding plate to the base of the upper case of the cabinet, (2) attaching the circuit board onto the shielding plate and fixing the circuit board and shielding plate in place with screws or other means to ensure anchoring and electrical continuity, then (3) attaching another shielding plate onto the circuit board and fixing the shielding plate on the circuit board with screws or other means, (4) putting the upper plate over it, then (5) turning over the electronic device, inserting anchoring screws or other anchoring members into holes formed on the lower surface of the lower case, and joining and anchoring it to the upper case. 
     But the problem with such a conventional assembly method is that the circuit board and shielding plates must each be screwed in place, which can make the assembly operation more complex. Not only does increasing the number of screw-on locations make the assembly operation more complex, it is also undesirable for making the electronic device smaller. And because the top surface of the cabinet of the electronic device is important for aesthetic design considerations, it is undesirable to allow anchoring screws, etc. to appear on the top surface of the cabinet, and the anchoring screws must be inserted from the lower surface of the lower case, which creates the problem that the operation of flipping over the electronic device during the assembly operation is unavoidable. 
     OBJECTS OF THE INVENTION 
     It is an object of the present invention, therefore, to provide an electronic device that makes it possible to simplify the assembly operation by reducing the number of screw-on locations and allows it to be made smaller by reducing the number of parts. 
     It is a further object of the present invention to provide an electronic device having multiple boards that are secured in a simplified manner within such device. 
     It is a further object of the present invention to provide an electronic device having multiple boards that are anchored to said device and are prevented from moving within said device. 
     Still other objects and advantages of the invention will become clear upon review of the following detailed description in conjunction with the appended drawings. 
     SUMMARY OF THE INVENTION 
     An electronic device is provided with a cabinet in which is housed multiple boards including a circuit board. The cabinet is formed by combining two cabinet members, one of which is provided with a recessed part and the other of which is provided with hold-down members. Multiple boards are housed and anchored within said cabinet member by the assembly of said cabinet members. 
     The use of hold-down members and the manner in which the boards are anchored reduces the number of screw-on locations, which is advantageous for making the electronic device smaller. 
     In addition, one of he multiple boards consists of a circuit board and two shielding plates cover the front and back surfaces of this circuit board, and the cabinet is made of a synthetic resin such as ABS resin or the like. The two shielding plates cover the front and back surfaces of the circuit board as an anti-EMI measure for the circuit board. 
     In addition, if a grounding pattern is formed on the board surface of said circuit board, it is desirable that the aforesaid holding-down members be constituted so that they are set in accordance with the shape of this grounding pattern, and when pressure is applied by the joining of the cabinet members, electrical continuity of the grounding pattern with the shielding plates is ensured. Thus, the need to ensure electrical continuity by holding the circuit board and shielding plates in place with screws, etc. is eliminated, which simplifies the assembly operation without detracting from the function of the shielding plates. In addition, forming the grounding pattern on the rim of the circuit board can ensure electrical continuity, securely regulate the movement of the circuit board and shielding plates within the cabinet before they are anchored in place by the anchoring members, and make handling easy during the assembly operation. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view showing the use of an electronic device of the present invention. 
     FIG. 2 is a perspective view of the electronic device of the present invention. 
     FIG. 3 is a perspective view showing the cover of the electronic device in the open position. 
     FIG. 4 is a perspective view showing a portion of the internal structure of the electronic device of the invention. 
     FIG. 5 is an exploded perspective view of an electronic device of the invention. 
     FIG. 6A is a partial perspective view showing the end of one of the shielding plates used in the electronic device of the invention. 
     FIG. 6B is a partial perspective view showing the end of another one of the shielding plates used in the electronic device of the invention. 
     FIG. 7 is a front view showing a portion of the accessory device of the invention. 
     FIG. 8 is a vertical cross-sectional view of the electronic device of the invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The following detailed description is of the best mode or modes of the invention presently contemplated. Such description is not intended to be understood in a limiting sense, but to be an example of the invention presented solely for illustration thereof, and by reference to which in connection with the following description and the accompanying drawings one skilled in the art may be advised of the advantages and construction of the invention. In the various views of the drawings, like reference characters designate like or similar parts. 
     FIG. 1 shows part of a living room  100  having set up therein a television receiver  3 , which outputs images and sound, etc., an entertainment device  1 , which is an electronic device that is connected to this television receiver  3 , and a controller  2 , which is an operation device that sends instructions to the entertainment device  1 . Entertainment device  1  for example reads a game program, etc. recorded on an optical disk, etc. and executes it according to instructions from controller  2  operated by the user (game player). 
     As shown in FIG. 2, entertainment device  1  comprises a device main body (not pictured), which has electronic parts, etc., and a cabinet  10 , which is preferably made of ABS resin and has an upper case  11  and a lower case  12 , which both accommodate the device main body. Upper case  11  further comprises a roughly circular cover  13  provided in the middle and an upper case main body  14  provided around this cover  13 . On the left side of cover  13  is a power button  15 , and on the right side of cover  13  is an open/close button  16 , into which is built an engaging member, not pictured, that advances and retracts with respect to cover  13  for opening and closing said cover  13 . As shown in FIG. 3, one end of cover  13  is rotatably attached to upper case main body  14 , such that between cover  13  and upper case main body  14  is a coil spring  17 , which is wound around the rotation shaft of cover  13  and biases the cover  13  open upon the pressing of button  16 . Specifically, in the state shown in FIG. 2, when button  16  is pressed, cover  13  opens due to the impelling force of coil spring  17 , and chucking member  62  (see FIG. 4, to be described below) is exposed. After cover  13  is opened, optical disk  4  is mounted onto chucking member  62 , and when cover  13  is closed and power button  15  is pressed, electric power is turned on to the device main body and the content recorded on optical disk  4  can be played back. 
     In addition, four openings  18  are formed on the front surface of cabinet  10  as shown in FIGS. 2-4; through which are exposed memory card connection parts  43 A (FIGS. 4 and 5) to be mounted on circuit board  40  (see FIG. 5 described below) and are positioned on the upper level of the openings  18 , and through which are exposed controller connection parts  43 B, which are likewise to be mounted on circuit board  40  and are positioned on the lower level of the openings  18 . Moreover, openings  18  where memory card connection parts  43 A are positioned are blocked by shutters  18 A, and when the end of a memory card (not shown) is pushed in, this shutter  18 A opens allowing the memory card to be connected to memory card connection part  43 A. 
     The side of cabinet  10  opposite the side on which openings  18  are formed is provided with an opening that exposes power connector  44  (FIG. 4) for supplying electric power from an external power source (not shown) to the device main body, and an opening that exposes audiovisual output terminal  45  for outputting to television receiver  3  the audio, video, and other signals recorded on the optical disk. 
     As shown in FIGS. 4 and 5, the device main body accommodated in cabinet  10 , comprises a circuit board  40 , which controls entertainment device  1 , metal shielding plates  51  and  52 , which are laminated with this circuit board  40  and cover the front and back surfaces of said circuit board  40 , disk device  60 , which includes optical pickup unit  61  mounted in contact with the upper surface of shielding plate  51 , and heat sink  70  as a heat dissipator of three-terminal regulator  46 , which is discussed below. Mounted on said circuit board  40 , besides various circuit elements including CPU  41 , and image processing unit  42 , are connection units  43 , which are constituted integrally with memory card connection parts  43 A and controller connection parts  43 B, power source connector  44 , and audiovisual output terminal  45 . Also, formed on circuit board  40  is a power supply wiring pattern for supplying electric power to CPU  41  via power source connector  44 , and mounted on this power supply wiring pattern is three-terminal regulator  46  for stabilizing the supplied voltage. In addition, grounding pattern  47  is formed on the rim part of such circuit board  40  for obtaining the ground electric potential. Moreover, although not pictured, this grounding pattern  47  is also formed on the rear-side rim part of circuit board  40 . Also, insertion holes  48  to be pierced by anchoring screws  80  are multiply formed in positions where grounding pattern  47  is formed on the front and rear end edges of circuit board  40 . 
     Shielding plate  51 , which covers the circuit element mounting surface of circuit board  40 , has flat plate-shaped part  511 , with which disk device  60  comes into contact, and rib-shaped part  512 , which is provided on the rim of this flat plate-shaped part  511 , and flat plate-shaped part  511  and rib-shaped part  512 , by covering three sides and the top of CPU  41  and image processing unit  42 , prevent electromagnetic waves from leaking outside the device from these circuit elements  41  and  42 . And as shown in FIG. 4, flat plate-shaped part  511  and rib-shaped part  512  are formed in such a way as to expose connecting unit  43  to the outside in the state in which circuit board  40  and shielding plate  51  are combined, and are constituted so that the electromagnetic waves generated from CPU  41 , etc. do not interfere with memory card connection parts  43 A or controller connection parts  43 B as noise. 
     As shown in FIG. 6A, pieces  513 A and  513 B, in which part of rib-shaped part  512  is cut upward, are multiply formed on the side of shielding plate  51  in positions corresponding to grounding pattern  47  on the rim of circuit board  40 . These cut-upward pieces  513 A and  513 B each have a slightly different cut-upward angle in the vertical direction: cut-upward pieces  513 A are set to an angle so that they are on the upper side with respect to the horizontal direction perpendicular to rib-shaped part  512 , and cut-upward pieces  513 B are set to an angle so that they are on the lower side with respect to the horizontal direction. In addition, three anchoring screw insertion holes  514  each are formed on the front and rear end edges of shielding plate  51 . 
     Shielding plate  52  consists of a metal flat plate material, and as with shielding plate  51 , as shown in FIG. 6B, multiple cut-upward pieces  521 , which are bent somewhat upward from the surface of shielding plate  52 , are formed on its side rim corresponding to the position of the grounding pattern in the rear surface of circuit board  40  and six anchoring screw insertion holes  522  are formed on the front and rear end edges of plate  52 . Moreover, although not pictured in FIG. 4, multiple bumps formed by press processing, etc. are formed in the middle part of shielding plate  52  so as to come into contact with the grounding pattern formed in the middle part on the rear surface side of circuit board  40  when in the combined state. 
     Disk device  60  is constituted so as to include optical pickup unit  61 , chucking member  62 , and case  63 , and housed inside case  63  are a motor (not shown) that causes chucking member  62  to turn and a motor (not shown) that causes optical pickup unit  61  to slide. Also, disk device  60  is electrically connected with circuit board  40  via a cable (not shown), and the recorded content of optical disk  4  that is detected by optical pickup unit  61  is sent as an electrical signal to CPU  41 , etc. of circuit board  40 . 
     Formed on the base of lower case  12 , in which such circuit board  40 , shielding plates  51  and  52 , and disk device  60  are accornmodated, are three protrusions  121  (see FIGS.  5  and  8 ), which stand approximately in the middle of case  12 , and insertion holes  122 , into which are inserted anchoring screws  80 , which serve as anchoring members, and multiple protrusions  123  formed on the inside rim surface of lower case  12 . The three protrusions  121  that stand approximately in the middle of case  12 , which are provided in order to support the weight of disk device  60 , pierce shielding plates  51  and  52  and circuit board  40  through openings therein and support the lower surface of disk device  60 . Therefore disk device  60  comes into direct contact with shielding plate  51 , but its own weight is supported strictly by protrusions  121 . For this purpose, three engagement holes  631  for engaging with protrusions  121  are formed on the rim of case  63 . Also, although not shown in the drawings, cushioning material is interposed between protrusions  121  and engagement holes  631 , and any vibration acting on entertainment device  1  is absorbed by this cushioning material to suppress any vibration of disk device  60 . 
     Meanwhile, on the inside rim surface of upper case  11  are formed protrusions  111  corresponding to the position of insertion holes  122  of lower case  12 , and panel-shaped ribs  112  are formed protruding in position corresponding to grounding pattern  47  of circuit board  40 , and these protrusions  111  and panel-shaped ribs  112  serve as holding-down members. As shown in FIG. 7, protrusions  111  are preferably cylindrical in shape, and formed inside them are screw holes  111 A that make threaded engagement with anchoring screws  80  (FIG.  5 ). Panel-shaped ribs  112  serve as holding-down members in the sense that they push circuit board  40  and shielding plates  51  and  52  against lower case  12  from the outside surface of these panels (FIG.  8 ), and are formed so as to correspond to the position of grounding pattern  47  on the circuit board  40  side. With these panel-shaped ribs  112 , reinforcing ribs  113  (FIG. 7) are formed in a grid pattern on the inside rim surface of upper case  11  near the base of panel-shaped ribs  112  so as to surround these panel-shaped ribs  112  in order that a force will act on these panel-shaped ribs  112  if upper case  11  and lower case  12  are assembled together to house circuit board  40 , shielding plates  51  and  52 , and disk device  60 . 
     Metal shielding plates  114  (FIG. 7) are provided on the inside rim surface of upper case  11  and correspond to openings  18  (FIGS. 2 and 3) that correspond to memory card connection parts  43 A; and cover the upper surface, side surfaces, and back surface of connection units  43 , and are constituted so that the input signals from controller  2  and the output signals to the memory card are affected by noise as little as possible. Also, shielding plates  114  are secured to the inside rim surface of upper case  11  and also function as a shutter holding means that hold shutters  18 A (FIGS.  2  and  3 ), which block openings  18  of memory card connection units  43 A, against upper case  11 . 
     The procedure for assembling entertainment device  1  as described above is as follows. 
     (1) Position shielding plate  52  inside lower case  12  such that the protrusions  121  extend through plate  52 . Then position circuit board  40  on shielding plate  52  such that protrusions  121  extend through board  40 . When positioning circuit board  40 , it is preferably to insert board  40  inside opening  18  obliquely from the back so that the tip of controller connection parts  43 B is exposed through openings  18 . 
     (2) Position shielding plate  51  on circuit board  40 , then put disk device  60  on top of plate  51  and cause the three protrusions  121  and engagement holes  631  to engage such that disk device  60  is supported by the three protrusions  121 . Connect the cable (not picture) connected to disk device  60  to the connector (not pictured) that is mounted on the back side of connection unit  43 . 
     (3) When the positioning of these is completed, engage the opening end rim of lower case  12  with the opening end rim of upper case  11 . In doing so, as shown in FIG. 8, pieces  513 A of shielding plate  51  are pushed against by said panel-shaped ribs  112 , and pieces  513 B are impelled against the surface of grounding pattern  47  of circuit board  40 , and the electrical continuity of shielding plate  51  and grounding pattern  47  is ensured. 
     (4) Then ensure that on the lower surface side of circuit board  40  the grounding pattern of circuit board  40  is in contact in an impelled state with pieces  521  or the bumps (not shown in the diagram), and that there is electrical continuity between shielding plate  51  and the grounding pattern  47  on the rear surface of circuit board  40 . 
     (5) With lower case  12  and upper case  11  engaged, flip over entertainment device  1  so that the base of lower case  12  is facing upward, insert anchoring screws  80  into insertion holes  122 , and screw anchoring screws  80  into female screw holes  111 A of protrusions  111  of upper case  11 . While in this engaged state, panel-shaped ribs  112  and protrusions  111  press circuit board  40  and shielding plates  51  and  52  from the outside direction, and the side surface of panel-shaped ribs  112  comes into contact with rib-shaped parts  512  of shielding plate  51 , so the constituent members inside do not move inside the cabinet even if the cabinet is flipped over and over. 
     Because protrusions  111  and panel-shaped ribs  112 , which serve as holding-down members, are provided in the entertainment device of the invention, when upper case  11  and lower case  12  are combined, circuit board  40  and shielding plates  51  and  52  are held down by protrusions  111  and panel-shaped ribs  112  so that they do not move even when, during assembly, entertainment device  1  is flipped over or turned upside-down. Therefore, using anchoring screws  80 , which join and anchor upper case  11  and lower case  12 , circuit board  40  and shielding plates  51  and  52  can be anchored in place, and the assembly operation can be simplified. 
     Also, because the assembly of the present invention does not require the screwing of shielding plates  51  and  52  to the circuit board  40  to assure the electrical continuity of circuit board  40  and shielding plates  51  and  52 , the number of screw-on locations can be reduced and the number of parts can be reduced, which is advantageous for making entertainment device  1  smaller. 
     In addition, because the construction is such that insertion holes  122  are formed on lower case  12  and anchoring screws  80  are inserted into these insertion holes  122 , anchoring screws  80  are prevented from being exposed on the top surface of cabinet  10 , which is desirable for the esthetic design of entertainment device  1 . 
     In addition, because female screw holes  111 A, which serve as joining parts, are formed in protrusions  111  as holding-down members, such holes do not have to be formed separately on the inside rim surface of upper case  11 , so the inner surface of the inner rim surface of upper case  11  can be simplified and the manufacturing cost of cabinet  10  can be reduced. 
     In addition, panel-shaped ribs  112 , which act as holding-down members, are set corresponding to grounding pattern  47 , and panel-shaped ribs  112  hold down pieces  513 A of shielding plates  51  and  52 , so that pieces  513 B and  521  are impelled against grounding pattern  47 , and the electrical continuity between shielding plates  51  and  52  and grounding pattern  47  of circuit board  40  is ensured, which is further desirable as an anti-EMI measure. 
     Also, because grounding pattern  47  is formed on the rim of circuit board  40 , the holding down of circuit board  40  and shielding plates  51  and  52  by panel-shaped ribs  112  can be made even more secure, the movement of these boards  40 ,  51 , and  52  within cabinet  10  can be securely restricted, flipping it upside-down and other such handling is made easy, and the assembly operation can be further simplified. 
     Morever, this invention is not limited to the above embodiment; it also includes modifications such as, but not limited to the following. 
     In the above embodiment, while grounding pattern  47  is formed on the rim part of circuit board  40 , and panel-shaped ribs  112  exert a pressing impelling force on shielding plates  51  and  52  and grounding pattern  47  a grounding pattern may be set in the middle part of the circuit board, and protrusion-shaped holding-down members may be positioned corresponding to the position of this grounding pattern. 
     Also, in the above embodiment, while the joining and anchoring of upper case  11  and lower case  12  is effected by anchoring screws  80 , the joining and anchoring of the upper case and lower case may also be effected by other anchoring members. 
     In addition, in the above embodiment, multiple cut-upward pieces  513 A,  513 B, and  521  are formed on the side edges of shielding plates  51  and  52 , but as long as electrical continuity with the grounding pattern of the circuit board can be ensured, it is not necessary to form cut-upward pieces. For example, electrically conductive material may be interposed between the shielding plates and the circuit board. Also, the electrical continuity between the grounding pattern and the shielding plates need not be done on the side edges of the circuit board; it may be done in any appropriate position on the circuit board. 
     And although this invention is described in connection with an entertainment device  1 , it may be applied to a personal computer or other electronic device. For example, one preferable embodiment might be a notebook-type personal computer having a cabinet made of synthetic resin. 
     In other respects, the specific structure and shape, etc. when implementing this invention may be made as other structures, etc. to the extent that the purpose of this invention can be achieved. 
     With this invention such as described above, because holding-down members that hold multiple boards against one cabinet member are provided on the other cabinet member, the multiple boards are held down in the state in which the two cabinet members are combined, preventing the multiple boards from moving within the cabinet even if the electronic device is turn upside-down. Therefore multiple boards can be held in place simultaneously by using anchoring members of the cabinet members, thus simplifying the assembly operation. 
     While the present invention has been described at some length and with some particularity with respect to the several described embodiments, it is not intended that it should be limited to any such particulars or embodiments or any particular embodiment, but it is to be construed with references to the appended claims so as to provide the broadest possible interpretation of such claims in view of the prior art and, therefore, to effectively encompass the intended scope of the invention.