Abstract:
An electronic apparatus includes an electronic device including electronic circuits, a first connector connected to the electronic circuit, and static electricity removal means, and a control device which includes a plurality of second connectors for connecting the electronic device and which is electrically connected to the static electricity removal means when the electronic device is being inserted and is electrically connected to the electronic device only via the first connector and the second connectors when the electronic device is mounted. Thus, it is possible to gradually discharge the static electricity when the electronic device is inserted into the control apparatus.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to an electronic apparatus capable of preventing devices from destruction and units from malfunction caused by discharging static electricity from an electronic device to be inserted into an electronic apparatus.  
           [0003]    2. Description of the Related Art  
           [0004]    A human body takes electric charge about 4×10 4  volts as electrostatic charge. When a person wears clothing of chemical fiber, it takes more electric charge. In the case of inserting an electrostatic charged device into an electronic apparatus and of discharging or sparking at a contact between the electronic device and the apparatus during the insertion or after insertion completed, built-in electronic elements may be destroyed or caused malfunction.  
           [0005]    According to Japanese Patent 2728747, a static electricity removal unit such as a static electricity removal brush is provided to slide along a cartridge containing an information recording medium and inserted into an information processing apparatus, so that the static electricity is discharged, thereby preventing the apparatus from the static electricity. Moreover, JP-A-6-349264 provides a static electricity removal unit not accompanied by electric discharge and fitted in a structure for inserting and ejecting a disc cartridge having accumulated static electricity into/from an external storage apparatus, thereby preventing the cartridge and apparatus from the static electricity.  
           [0006]    However, unless an electric cut-off unit is provided, the electronic apparatus having electric circuit is damaged and electric elements of the electric circuit is destroyed, or a memory content is destroyed to cause malfunction by the static electricity attributed to external disturbance from outside of the electronic apparatus.  
           [0007]    Moreover, when the static electricity removal unit is made from a material such as an extremely low electric resistance, the discharge is caused all at once and destroys a peripheral circuit depending on the resistance to voltage of the storage apparatus.  
           [0008]    Thus, in the case of the electronic apparatus having a plurality of electronic devices detachably attached to the electronic apparatus and of inserting a charged electronic device into the electronic apparatus, the discharge or spark occurs via a connection portion between the electronic apparatus and the electronic device, which may destroy the electronic elements in another electronic device or cause malfunction.  
         SUMMARY OF THE INVENTION  
         [0009]    It is therefore an object of the present invention to provide an electronic apparatus capable of gradually discharging the static electricity when an electronic device is inserted into the electronic apparatus, thereby preventing the electronic device and an element in another electronic device from damage or malfunction and preventing the devices from electric damage by external disturbance from outside of the electronic device after mounted.  
           [0010]    According to the electronic apparatus of the present invention, at a time of inserting a detachable electronic device into the electronic apparatus, the electronic device is grounded via the electronic apparatus by a static electricity removal unit made from a material having flexibility. When the insertion is complete, no electric connection is made between the electronic device and the electronic apparatus except for an electric connection unit.  
           [0011]    Furthermore, the static electricity removal unit is made from a material having an electric resistance not smaller than 2.5×10 5  Ω, and gradual discharge is enabled.  
           [0012]    Moreover, the electronic device may be a storage unit in which a storage device such as a magnetic disc device and an optical disc device and electronic parts are built therein. In this case, the electronic apparatus has a plenty of storage units.  
           [0013]    Other objects, features and advantages of the invention will become apparent from the following description of the embodiments of the invention taken in conjunction with the accompanying drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]    [0014]FIG. 1 is a perspective view showing an outline of an electronic apparatus according to the present invention.  
         [0015]    [0015]FIG. 2 shows a connection portion between the electronic apparatus of the present invention and an electronic device.  
         [0016]    [0016]FIG. 3 shows an outline of a magnetic disc unit according to the present invention.  
         [0017]    [0017]FIG. 4 shows the magnetic disc unit of FIG. 3 mounted on a storage system apparatus.  
         [0018]    [0018]FIG. 5 shows an outline of another example of the magnetic disc unit according to the present invention.  
         [0019]    [0019]FIG. 6 shows the magnetic disc unit of FIG. 5 mounted on a storage system apparatus.  
         [0020]    [0020]FIG. 7 is a perspective view of an insulation unit insulating a guide rail groove of the storage system apparatus on which the magnetic disc unit of FIG. 3 is mounted.  
     
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS  
       [0021]    Description will now be directed to embodiments of the present invention with reference to FIG. 1 to FIG. 6.  
         [0022]    [0022]FIG. 1 shows a storage system apparatus according to the present invention. The storage system apparatus  1  has a plurality of detachable magnetic disc units  2  having a built-in disc drive and electronic parts. Hereinafter, the magnetic disc unit will be referred to simply as a unit.  
         [0023]    [0023]FIG. 2 shows a connection portion between the unit  2  (HDD- 1 , HDD- 2 ) and the main body of the storage system apparatus  1 . A plurality of connectors  123  are connected to a disc array controller  11  controlling the entire operation of the storage system apparatus  1 . The storage apparatus system  1  and the unit  2  are connected to each other by the connector  123  and a connector  102  of the unit. The disc array controller  11  can control the disc drive in the unit  2 .  
         [0024]    Here, when the unit  2  is inserted into the storage system apparatus  1 , if the unit  2  is charged by the static electricity, discharge or spark occurs via the connectors  102 ,  123 , which may destroy the electronic parts of another unit or cause malfunction. That is, if the unit  2  (HDD- 1 ) is charged when the unit  2  (HDD- 1 ) is inserted thereinto, the static electricity is discharged when the connector  102  is connected to the connector  123  and the electricity flows into the unit  2  (HDD- 2 ) connected by the connector  123  and the connector  102 . Thus, there is a case that the content of a memory  22  which is an electronic part of the unit  2  (HDD- 2 ) is destroyed by the discharge from the unit  2  (HDD- 1 ) and trouble is caused in the operation of the unit  2  (HDD- 2 ).  
         [0025]    [0025]FIG. 3 shows the magnetic disc unit  2  according to the present invention. The unit  2  includes a main body  101  having a disc drive and electronic circuits, a connector  102  extending from the main body  101 , a holder  105  holding the main body  101 , a pair of opposing guide rails  103  for inserting the unit  2  into a correct position, a handle  104  for inserting and conveying the unit  2 , and a static electricity removal brush  106  connected to the holder  105 . The main body  101 , the holder  105 , and the electricity removal brush  106  are electrically connected to one another.  
         [0026]    [0026]FIG. 4 is a longitudinal cross sectional view of the magnetic disc unit  2  of FIG. 3 inserted into the storage system apparatus  1 . A pair of opposing guide rails grooves  120  including an insulation sheet  121  are arranged at the position corresponding to the upper and the lower guide rail  103 . Moreover, the connector  123  is provided at a position corresponding to the connector  102 , so that the unit  2  and the storage system apparatus  1  are electrically connected. When the unit  2  is charged by the static electricity, the discharge occurs via the connector  102  and the connector  123 , adversely affecting another unit  2 .  
         [0027]    The guide rail groove  120  is electrically connected to the storage system apparatus  1  and is grounded. Here, when the guide rail  103  is made from an electrical insulation material such as synthetic resin, the insulation sheet  121  is not needed. When the guide rail  103  is made from an electrical conductor such as a metal, as shown in FIG. 7, in order to obtain electric insulation from the holder  105 , the cross section of the insulation sheet  121  is made into U shape and built into the guide rail groove  120  using adhesive.  
         [0028]    When the unit  2  is completely inserted into the storage system apparatus  1 , the electricity removal brush  106  is at a distance “a” from the guide rail groove  120  and at a distance “b” from the storage system apparatus  1 , thereby obtaining a sufficient space  124  for insulation of the electricity removal brush  106  and the storage system apparatus  1 . Moreover, the electricity removal brush  106  has a length shorter by “c” than the interval between the electricity removal brush  106  and the guide rail groove  120 . Accordingly, when inserting the unit  2  into the storage system apparatus  1 , the electricity removal brush  106  can be surely brought into contact with the guide rail groove  120 .  
         [0029]    The human body is generally charged with static electricity. When a person wears clothing made of chemical fiber, the person may be charged to not smaller than 1×10 6  volts. When the main body  101  is charged because of an artificial reason and the unit  2  containing the main body  101  is inserted into the storage system apparatus  1 , firstly, the electricity removal brush  106  is brought into contact with the guide rail groove  120  to remove the static electricity. When the insertion is complete, a sufficient space  124  can be obtained and portions other than the connection portion between the connector  102  and the connector  123  are electrically insulated.  
         [0030]    Consequently, it is possible to prevent logic control elements (not depicted) of the main body  101  from damage and malfunction of the information processing due to external disturbance accompanying the static electricity applied to the storage system apparatus  1  during and after the insertion.  
         [0031]    Moreover, if the electricity removal brush  106  shown in FIG. 3 and FIG. 4 is made of a material having electric resistance not smaller than 2.5×10 5  Ω, the discharge will not occur all at once when the electricity removal brush  106  is in contact with the guide rail groove  120  for discharge, and it is possible to prevent peripheral circuits from an abrupt discharge. The value of the electric resistance may be a value for handling the instantaneous discharge value which the disc drive in the unit  2  can stand. When the disc drive has a resistance to a large instantaneous discharge voltage, there is no problem if the electricity removal brush  106  has a resistance lower than the aforementioned value. Moreover, on the contrary, the resistance must be a value enabling the discharge before the disc drive is inserted completely. Actually, which of resistances the value is used depends on the resistance to voltage of the disc drive and the structure of the disc drive. It is preferable to select a material which satisfies the allowance in each case. The same applies to the electricity removal brush  106  shown in FIG. 6.  
         [0032]    [0032]FIG. 5 shows the magnetic disc unit  2  according to another embodiment of the present invention.  
         [0033]    The unit  2  of this embodiment includes a main body  101  having a disc drive and electronic parts, a connector  102  extending from the main body  101 , a holder  105  for holding the main body  101 , a pair of opposing guide rails  103  for inserting the unit  2  into a correct position, and a handle  104  for inserting and conveying the unit  2 . The main body  101  and the holder  105  are electrically connected to each other.  
         [0034]    [0034]FIG. 6 is a longitudinal cross section of the unit  2  of this embodiment inserted into the storage system apparatus  1 . A pair of opposing guide rail grooves  120  are arranged at the position corresponding to the guide rail  103  above and below. The guide rail groove  120  is electrically insulated from the storage system apparatus  1 . Moreover, the connector  123  is arranged at the position of the storage system apparatus  1  corresponding to the connector  102  for electrical connection between the unit  2  and the storage system apparatus  1 . When the unit  2  is charged by the static electricity, the discharge or spark occurs via the connector  102  and the connector  123 , adversely affecting another unit.  
         [0035]    With the unit  2  mounted on the storage system apparatus  1 , the electricity removal brush  106  has a space  224  of dimension “d” from the holder  105 . Moreover, the electricity removal brush  106  has a length longer by “e” than the distance between the electricity removal brush  106  and the holder  105 . Accordingly, when the unit  2  is inserted into the storage system apparatus  1 , the electricity removal brush  106  can surely be in contact with the guide rail groove  120 .  
         [0036]    Since the human body is charged by the static electricity, the main body  101  is charged because of the artificial reason. When the main body  101  is inserted into the storage system apparatus  1 , firstly, the electricity removal brush  106  is brought into contact with the holder  105  to remove the static electricity. When the insertion is complete, a sufficient space  224  is present and portions other than the connection portion between the connector  102  and the connector  123  are electrically insulated.  
         [0037]    Accordingly, it is possible to prevent logic control elements (not depicted) built in the main body  101  from damage or malfunction of information processing due to external disturbance accompanying the static electricity applied to the storage system apparatus  1  during and after an insertion.  
         [0038]    In the aforementioned embodiment, it is also possible to use an urging member such as a spring for stabilizing the unit  2  as the electricity removal brush  106 . In this case, the same effect as the present invention can be obtained if the following configuration can be obtained. That is, when the unit  2  is inserted, the unit  2  is assured to be electrically connected to the storage system apparatus  1  via the urging member. When the unit  2  is then mounted on the storage system apparatus  1 , the unit  2  and the storage system apparatus  1  are electrically insulated from each other.  
         [0039]    Moreover, the electronic device inserted into the electronic apparatus to replace the storage system apparatus  1  is not limited to a magnetic disc unit. For example, the present invention should be applied to a device such as an additional frame connection device (device for connecting an additional frame body for adding an electronic device and an electronic apparatus via a connector to which the electronic device is connected). That is, a device which may discharge static electricity via the connector if the device is charged during insertion and may be affected, while mounted, by static electricity discharged during insertion of another device.  
         [0040]    As has been described above, according to the present invention, when the detachable charged unit  2  is inserted into the storage system apparatus  1 , the unit  2  or the storage system apparatus  1  has, for example, the electricity removal brush  106  having electric resistance not greater than 1×10 6  Ω and it is possible to flow the static electricity energy to the ground through the storage system apparatus  1  at the initial stage of the insertion. Moreover, when the insertion of the unit  2  is complete, portions other than the connector  102  are not electrically connected to the storage system apparatus  1  and the unit  2  and a sufficient space can be obtained not in contact with the electricity removal brush  106 .  
         [0041]    Consequently, when inserting the unit  2  to be connected to the storage system apparatus  1  via the connector  102 , it is possible to protect the unit  2  from adverse affect caused by discharge of the static electricity and prevent the built-in electronic elements from damage or malfunction. Furthermore, it is possible to prevent the electronic elements from the electric damage due to an external disturbance from outside of the unit  2  after mounted.  
         [0042]    Moreover, by using the material having electric resistance, for example, not lower than 1×10 5  Ω for the electricity removal brush, it is possible to prolong the discharge time during discharge, thereby preventing the circuits from damage due to an instantaneous discharge.  
         [0043]    It should be further understood by those skilled in the art that although the foregoing description has been made on embodiments of the invention, the invention is not limited thereto and various changes and modifications may be made without departing from the spirit of the invention and the scope of the appended claims.