US Patent 7777680 Electronic apparatus and timepiece

In an antenna device of a wristwatch, a pair of external magnetic members each attached to a respective one of both ends of a magnetic core effectively collects the magnetic flux of a standard time and frequency signal. The collected magnetic flux passes through the core around which a coil is wound, thereby inducing an electromotive force and hence improving the reception accuracy of the signal. The pair of external magnetic members screens out undesirable external magnetism which would otherwise influence motors that drive a hand shaft and hands, thereby achieving accurate hand driving and improving the high watch accuracy.