Electronic timepiece with internal antenna
An electronic timepiece has; an annular antenna; and a time display unit. The antenna includes an annular dielectric; a conductive driven element that is disposed on the dielectric, is ring-shaped with a notch therein (C-shaped), and is fed with a specific potential; and a conductive parasitic element that is disposed on the dielectric with a gap to the driven element, and is an endless ring or a ring with a notch therein (C-shaped). A feed position to which a specific potential is fed is disposed to the driven element at one place. When the electronic timepiece is seen in plan view, the feed position is disposed in a range from approximately 8:00 to approximately 10:00 relative to the center (center pivot) of the electronic timepiece.
1. An electronic timepiece with internal antenna, comprising:
a cylindrical case;
a back cover that covers an opening of the cylindrical case;
an annular antenna; and
a time display unit that displays time;
wherein the antenna includes an annular dielectric, a conductive driven element that is disposed on the dielectric, is ring-shaped with a notch therein, and is fed with a specific potential, and a conductive parasitic element that is disposed on the dielectric with a gap to the driven element, and is an endless ring or a ring with a notch therein, wherein the conductive parasitic element is electrically isolated from potential supplied by an external source;
a feed position to which a specific potential is fed is disposed to the driven element at one place, and
the feed position is disposed in a range from approximately 8:00 to approximately 10:00 relative to the center of the electronic timepiece with internal antenna when the electronic timepiece with internal antenna is seen in plan view.
2. The electronic timepiece with internal antenna described in claim 1 , wherein:
the driven element is disposed on the inside of the parasitic element relative to the center axis of the dielectric.
3. The electronic timepiece with internal antenna described in claim 1 , wherein:
the dielectric has a flat top surface, and a slope formed from the top surface so that the height to the time display unit decreases to the inside; and
the driven element is disposed on the slope.
4. The electronic timepiece with internal antenna described in claim 1 , further comprising:
a circuit board having a reception circuit disposed thereto; and
a coil spring that is disposed at the feed position, and feeds a specific potential to the driven element;
wherein one end of the coil spring is electrically connected to the driven element, the other end is electrically connected to the circuit board and is fed with the specific potential, and the side part not including both ends is surrounded by a cylindrical conductive member to which ground potential is supplied.