| 摘要 |
A reading device 2 is equipped with sensor substrates 7L and 7R. An ASIC switches the sensor substrates 7L and 7R alternately between a first state and a second state. In the first state, one of the sensor substrates is in a transmitting/receiving state wherein the sensor substrate switches alternately between a transmitting state in which current is conducted to multiple coils and a receiving state in which an inductive current in the multiple coils can be detected, while at the same time the other sensor substrate is in a continuous reception state wherein the receiving state, in which an inductive current in the multiple coils can be detected, is maintained. In the second state, the sensor substrate is in the continuous reception state and the other is in the transmitting/receiving state. The ASIC determines that an open state exists when inductive current is not flowing in the multiple coils of the sensor substrate 7L or 7R that is in the continuous reception state, and determines that a closed state exists when inductive current is flowing. In the closed state, the ASIC switches the state of the sensor substrates 7L and 7R from a normal state with relatively high power consumption to a first power-saving state with relatively low power consumption. |
