| 摘要 |
PURPOSE:To prevent the titled IC card reader previously from the short-circuit of a power supply or the danger of fire due to the insertion of an foreign substance by detecting a connecting state between contact terminals and discriminating whether an IC card is normally inserted or not on the basis of a compared result with a previously set reference value. CONSTITUTION:After inserting an IC card into a card insertion part and contacting the contacts C1, C2... of the IC card with the contact terminals C11, C12..., a power source is turned on. At that time, a switch SW is turned off, power is supplied from a power supply line Vcc to the contact C1 of the IC card through a current restricting resistor RO and the contact terminal C11 and the contact C2 of the IC card is earthed through the contact terminal C12. The voltage of a point A, i.e. a detecting voltage, is included within a fixed range (between reference voltages VH and VL) when the IC card is normally inserted into the card insertion part, and is other cases, not included within the fixed range. |
