Abstract:
An electronic apparatus is adapted to be used with a portable storage medium installed therein. The apparatus includes a mounting portion in which a unit for driving a portable storage medium is mounted. The mounting portion is constituted by a metal plate. When a storage medium is installed, an opening of the metal plate into which said storage medium is inserted is electrically connected between an upper portion and a lower portion thereof, so that the metal plate does not resonate with radio waves generated outside of the apparatus.

Description:
BACKGROUND OF THE INVENTION. 
     1. Field of the Invention 
     The present invention relates to an electronic apparatus on which a portable storage medium can be detachably mounted and which is adapted to be used with the portable storage medium being mounted, and more particularly to an electronic apparatus utilizing a portable storage medium for preventing resonance generated by the configuration or construction of a metal plate or the like on an insertion face of a unit into which a portable storage medium, such as a magnetic disk, an optical disk or a magneto-optical disk, is inserted for use when radio waves are generated outside the unit or equipment in which the unit is installed to thereby prevent, in turn, a malfunction of the unit. 
     In recent years, portable electronic equipment and portable radio equipment have become common, and there has been a growing tendency that both are used, simultaneously, in a closed environment. As a result of this, there can occur a case where a strong electro-magnetic field is applied from the radio equipment to the electronic equipment in which a portable storage medium is installed. When this happens, the peripheral portion of the equipment which surrounds the installed portable storage medium may resonate, and the level of electro-magnetic field is increased,.whereby the read circuit or the like of the electronic equipment is caused to malfunction. 
     As countermeasures against the malfunction described above, there has been a demand for an increase in resistance to electromagnetic fields by configuring and/or constructing the metal plate on the insertion face where the portable storage medium is inserted or a metal plate at the mounting portion of the unit such that they do not resonate even when affected by radio waves or by modifying the distribution of electro-magnetic field inside the unit. 
     2. Description of the Related Art 
     Conventionally, since no countermeasures against electro-magnetic fields have been taken in considering the size of a metal plate constituting the insertion face for a portable storage medium, there has been a problem that the metal plate resonates with radio waves generated outside, whereby the electro-magnetic field of the radio waves is increased to thereby cause the read circuit of a unit using a portable storage medium to malfunction. 
     As an example, a theoretical case will be described in which resonance occurs. Resonance by radio waves is generated when the length of a conductor or the size of frontage becomes a half the wave lenght (λ) of the radio waves or a multiple of an integer number of the wave lenght. For example assuming that size of the portable storage medium insertion face is 1×10 cm and that the frequency (f) of an radio wave is 1.5 GHz, then the wave length of the electronic radio wave is obtained from the following representation: 
     
       
         Wave length λ( m )= C/f   (1); 
       
     
     Where, 
     C is the velocity of light, 3×10 8  (m/s) 
     f is frequency (Hz) 
     and if the actual numerals are substituted for those in the representation (1), 
     
       
         Wave length λ=3×10 8 /1.5×10 9 =0.2 m(20 cm)  (2) 
       
     
     Therefore, one half the wave length λ is 10 cm, and since this coincides with the longitudinal size of the portable storage medium insertion face in the conventional apparatus, resonance may be generated to cause a malfunction of the apparatus. 
     As is described above, conventionally, there was a risk that resonance is generated by the configuration or construction of the metal plate or the like on the portable storage medium insertion face, whereby the electro-magnetic field strength of the radio wave is increased, resulting in a malfunction of the unit using the portable storage medium. 
     SUMMARY OF THE INVENTION 
     With a view to solving the aforesaid problem, an object of the present invention is to provide an electronic apparatus utilizing a portable storage medium which has is constructed to absorb radio waves and improving its resistance, a construction for improving the yield strength for accommodating a unit or a construction for configuring a metal plate or the like on a portable storage medium insertion surface such that no resonance is generated. 
     With a view to attaining the aforesaid object, according to the present invention, there is provided an electronic apparatus, adapted to be used with a portable storage medium being installed therein, utilizing a portable storage medium characterized in that a metal plate or the like on a portable storage medium insertion face is configured or constructed such that the metal plate or the like does not resonate with radio waves generated outside the apparatus. 
     In this case, the size of the metal plate or the like on the portable storage medium insertion face is selected such that the size does not have a ½λ, ¼λ, . . . relation or a multiple of an integer number relation to the wave length(λ) of the radio waves. 
     In addition, according to the present invention, there is provided in an electronic apparatus in which a portable storage medium is removably installed, and which is adapted to be used with the portable storage medium being installed therein, utilizing a portable-storage medium characterized by a construction in which a mounting portion where a unit for driving a portable storage medium is mounted is constituted by a metal plate and in which, when a storage medium is installed, an opening in the metal plate into which the storage medium is inserted is electrically connected between an upper portion and a lower portion thereof, so that the metal plate does not resonate with radio waves generated outside. 
     In this case, flexible flaps are provided at the upper and lower portions of the opening in the metal plate so that the flaps and the metal plate are brought into electrical contact with each other. 
     In addition, according to the present invention, there is provided, in an electronic apparatus adapted to be used with a portable storage medium being installed therein, an apparatus for utilizing a portable storage medium characterized by a construction in which a mounting portion where a unit for driving a portable storage medium is mounted is constituted by a metal plate, and in which upper and lower portions of a rearward metal plate are connected to each other and are situated on an opposite side to the side where the storage medium is inserted, so that the metal plate does not resonate with radio waves generated outside. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows a desktop type computer as an electronic equipment and a portable telephone as a portable radio equipment; 
     FIG. 2 shows a part of the electronic equipment indicated by A in FIG. 1 and a portable storage medium insertion portion with a front decorative cover (not shown) removed; 
     FIG. 3 is a perspective view of an insertion portion of a storage medium according to a first embodiment of the invention; 
     FIG. 4 is a perspective view of an insertion portion of a storage medium according to a second embodiment of the invention; 
     FIG. 5 is a perspective view of an insertion portion of a storage medium according to a third embodiment of the invention; and 
     FIG. 6 is a drawing of the third embodiment of the present invention seen from the rear of the unit. 
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Referring to the accompanying drawings, embodiments of the present invention will be described below. 
     FIG. 1 shows a desktop type computer as electronic equipment and a portable telephone as a portable radio equipment. As shown in the drawings, in recent years, there is a growing tendency that both are simultaneously used in a closed environment. As is well known, the desktop type computer  1  comprises an apparatus main body  1  on a lower side thereof and a display  3  adapted to be placed on the apparatus main body. Provided on a right-hand side of a front side of the apparatus main body are a portable storage medium insertion portion  4  or an insertion portion  5  for a floppy disk (FD) and an insertion portion for a compact disk (CD), which are disposed in parallel with each other in a vertical direction. Although there is a growing tendency for a portable telephone  7  to be used at apposition close to the computer  1 , as described above, the relationship between the wave length (λ) of an radio wave and the configuration or construction of the medium insertion portion is important. 
     FIG. 2 shows a part of the electronic equipment indicated by reference numeral  4  in FIG. 1 and a portable storage medium insertion portion with a front decorative cover (not shown) removed. Formed in a front side of an apparatus box  11  formed of sheet metal are a rectangular hole for inserting thereinto a floppy disk device  12  and a rectangular hole  15  for inserting thereinto a compact disk device  14  in such a manner as to be disposed in parallel in a vertical direction. The floppy disk device  12  and the compact disk device  14  protrude forward from the respective rectangular holes  13 ,  15  by a distance equal to the thickness A of a front decorative cover (not shown). The floppy disk device  12  is fixed with a screw  17  to a mounting portion  16  formed of sheet metal which is provided in the interior of the apparatus box  11  for fixing a floppy disk. Reference numeral  18  denotes an insertion port for a floppy disk (not shown) and reference numeral  19  denotes a loading portion for a compact disk (not shown). 
     The size of the rectangular hole  13  for insertion thereinto of the floppy disk device  12  is determined to such an extent that the floppy disk device  12  just fits therein, and therefore the horizontal length B of the opening of the rectangular hole  13  is about 10 cm. This is, as described above, just one half the wave length (20 cm) of the frequency the portable telephone  7  uses, and the horizontal length is the size which resonates with this radio wave. On the other hand, the horizontal length of the frontage of the rectangular hole  15  for insertion thereinto of the compact disk device  14  is longer than the horizontal length of the frontage of the rectangular hole  13  for insertion thereinto of the floppy disk device  12 , and the horizontal length of the rectangular hole  15  does not become ½ or ¼ the wave length (20 cm) of the frequency the portable telephone uses, whereby there is no risk of resonance being generated. 
     FIG. 3 shows a perspective view of an insertion portion, for a storage medium, of electronic equipment according to a first embodiment of the present invention, in which the horizontal size C of the front of the rectangular hole  13  for insertion thereinto of the floppy disk device is determined so as to be larger than the size B shown in FIG. 2 so that the size does not coincide with ½ or ¼ the wave length (20 cm) of the frequency that the portable telephone uses. It is identical to that shown in FIG. 2 in that the floppy disk device  12  is fixed with the screw  17  to the mounting portion  16  formed of sheet metal which is provided in the interior of the apparatus box for fixing the floppy disk device. In addition, the vertical size of the frontage of the rectangular hole  13  is not in direct relation to the frequency that the portable telephone uses, and therefore, it may be the same as the vertical size of the rectangular hole shown in FIG.  2 . 
     FIG. 4 shows a perspective view of an insertion portion of a storage medium in electronic equipment according to a second embodiment of the invention, and the size of the rectangular hole  13  for insertion of the floppy disk device  12  is determined to such an extent that the floppy disk device  12  just fits therein and the horizontal length of the frontage of the rectangular hole  13  is about 10 cm. However, in this embodiment, at a front region of the apparatus box  11 , sheet metal portions extend forward from upper and lower central portions of the floppy disk device insertion rectangular hole  13  to a portion just in the vicinity of the medium insertion portion of the floppy disk device, and flaps  21   a,    21   b  formed of a soft material, such as a resin (for example, polyester film or the like) are attached to the distal ends of the extending-portions  20   a,    20   b.  These flaps  21   a,    21   b  are extended to such antextent that they approach each other, so that the extending flaps can close the insertion portion for a medium for the front side of the floppy disk device  12  insertion portion. These flaps  21   a,    21   b  are constructed so as to be deflected in a direction in which a floppy disk (not shown) is inserted, and a conductive metallic plating is coated on the surface of the resin through metallization so as to establish an electric communication with the sheet metal portion of the apparatus box  11 . 
     Consequently, when the frontal decorative panel (not shown) of the computer is mounted, there is provided a state in which the distal ends of the flaps  21   a,    21   b  protrude to a portion in the vicinity of the panel. Then, a floppy disk is inserted into the insertion hole  18  of the floppy disc device  12  through between the upper and lower flaps  21   a,    21   b.  When this happens, the upper and lower flaps  21   a,    21   b  deflect in the direction in which the floppy disk is inserted, and when the insertion of the floppy disk is completed, these upper and lower flaps  21   a,    21   b  come into contact with each other whereby, even if the horizontal size of the frontage of the rectangular hole  13  is B, since the intermediate portion is short circuited, it does not resonate with electro-magnetic waves from the outside such as from a portable telephone, whereby the shielding effect can be improved. 
     FIG. 5 is a perspective view of an insertion portion of a storage medium in electronic equipment according to a third embodiment of the invention as viewed from the front, and FIG. 6 is a schematic perspective view showing a drive portion of the same embodiment as viewed from the rear. In this embodiment, an opening  26  is formed in each side of a rear portion of, for example, a mounting portion  25  formed of a conductive metal, such as a sheet metal, for accommodating and fixing the floppy disk device  12 , and an upper portion  28  and a lower portion  29  are coupled together at a central portion  27 , whereby radio waves resonating in the opening portion of the floppy disk insertion portion  18  can be moved rearward. Consequently, the resonance can be suppressed by virtue of the existence of the central connecting portion  27  which mechanically and electrically connects between the upper portion  28  and the lower portion  29  of the mounting portion  25 . In addition, it is identical to the previous embodiment in that the floppy disk device  12  is fixed with a screw (not shown) making use of a screw fastening hole  31  formed in the mounting portion  25  and a tapped hole  32  formed in the floppy disk device.