Patent ID: 7027363

Claim:
A time measurement system comprising a master station that receives external time data and outputs a time signal on the basis of the external time data and a slave station that receives the time signal from the master station and corrects the time on the basis of the external time data, wherein the slave station includes a reference signal generating circuit that generates a reference signal; a timekeeping circuit that keeps time on the basis of the reference signal; a driving motor with a driving coil; a receiver circuit that is connected to the driving coil and that receives the time signal using the driving coil as a receiving coil; a control circuit that corrects the time kept by the timekeeping circuit on the basis of the time signal received by the receiver circuit; and a time display unit that displays the time kept by the timekeeping circuit, and wherein the master station includes a time data receiver that receives the external time data; a time signal generating circuit that generates a time signal on the basis of the received time data, the time signal being receivable by the driving coil of the slave station; a transmitter circuit and a communication coil that transmit the time signal; and a control circuit that controls the operation of the time data receiver, the time signal generating circuit, and the transmitter circuit; and the master station further including a transmission timing setting circuit; and wherein the control circuit of the master station controls the transmission timing setting circuit to set a transmission time of the time signal so that it does not overlap a time at which a motor drive pulse of the slave station is output.