Leydig, Voit & Mayer
Portable semiconductor data storage device with disconnectable ground connection
 In a portable semiconductor storage device, a negative electrode terminal electrically connected to the circuit ground of a board contained in the portable semiconductor storage device contacts both the negative polarity of a cell and conductive outer plates on both sides of the circuit board when the cell is present in the device. When the cell is not present, the circuit ground of the board is not brought into contact with the conductive outer plates. Therefore, backup data can be protected from being destroyed due to external noise when the cell is present, and ground superimposed noise from the conductive outer plates can be cut off when the cell is not present, aiding in the stable operation of the entire system. Since the circuit ground is connected to the conductive outer plates by means of a terminal member of a simplified constuction, an assembly process can be simplified. Thus, the present invention has an advance in that the reliability of the portable semiconductor storage device is enhanced and the cost is lowered. 
Mitsubishi Denki Kabushiki Kaisha
H H
H01R H01R
additional inventional
Takayuki Yoshihide
Shinohara Mori