Wrist watch containing internal tag, radio watch, and antenna for wrist watch

A wrist watch with internal tag, comprising:

• a watch case comprising a ring shaped case, a glass lid configured to seal a front side of said ring shaped case, and a rear lid configured to seal a rear side of said ring shaped case;
• a drive section housed in said watch case;
• a display section housed in said watch case, the display section being configured to be driven by said drive section and to display a time instant;
• and
• an RFID tag which is housed in said watch case and comprises an antenna and an IC chip;
• wherein said antenna comprises a magnetic backing provided to follow around an inner surface of said rear lid, a pair of magnetic core members configured to project from said magnetic backing on opposite sides of said drive section, and a series coil which is wound in a helical shape upon said pair of magnetic core members.

A radio watch, comprising:

• a watch case comprising a ring shaped case, a glass lid configured to seal a front side of said ring shaped case, and a rear lid configured to seal a rear side of said ring shaped case;
• a drive section housed in said watch case;
• a display section housed in said watch case, the display section being configured to be driven by said drive section and to display a time instant;
• an antenna configured to receive a radio signal including time instant information;
• and
• a controller housed in said watch case and configured to control said drive section based upon the detected an output from said antenna;
• wherein said antenna is configured to be between said ring shaped case and said drive section and to follow around an inner surface of said ring shaped case;
• and
• said ring shaped case is formed from a metallic material, and said ring shaped case comprises a first slit configured to cut completely through said ring shaped case in at least one place.

An antenna for a wrist watch which comprises a watch case comprising a ring shaped case, a glass lid which seals a front side of said ring shaped case, and a rear lid which seals a rear side of said ring shaped case, and a drive section which is housed in said watch case, wherein:

• said antenna is housed within said watch case, and comprises a magnetic core member and a coil assembly;
• said magnetic core member has a hole in which said drive section can be inserted, and is formed in a ring shape which can be inserted between said drive section and said ring shaped case;
• and
• said coil assembly comprises a first coil which is wound around the outer peripheral surface of said ring shaped magnetic core member so as to have a magnetic core axis which coincides with the central axis of said ring shaped magnetic core member, and a second coil which is wound in a helical shape upon said ring shaped magnetic core member so as to have said ring shaped magnetic core member as its magnetic core axis.