Electronic watch having improved antenna function

Patent metadata

Field	Value
Publication number	US-12436507-B2
Application number	US-202218083906-A
Country	US
Kind code	B2
Filing date	Dec 19, 2022
Priority date	Dec 20, 2021
Publication date	Oct 7, 2025
Grant date	Oct 7, 2025

Abstract

An electronic watch includes a case having electrical conductivity, a cover member attached to the case, a hand, a hand shaft to which the hand is attached, and an antenna disposed to overlap the cover member in plan view from a first direction, the antenna being configured to receive a predetermined radio wave, the cover member is made of a material that shortens a wavelength of the radio wave, the case includes a facing surface facing a side surface of the cover member, the facing surface being located within a predetermined dimension from the side surface, and in the first direction, a height dimension from an end portion of the facing surface positioned farthest from the antenna to a farthest portion of the cover member positioned farthest from the antenna is equal to or greater than 1/60 of the wavelength shortened by the cover member.

First claim

What is claimed is:

1. An electronic watch, comprising:
a case having electrical conductivity;
a cover member attached to the case;
a hand;
a hand shaft to which the hand is attached; and
an antenna disposed so as to overlap the cover member in plan view when viewed from a first direction parallel to an axial direction of the hand shaft, the antenna being configured to receive a predetermined radio wave, wherein
the cover member is made of a material configured to shorten a wavelength of the radio wave,
the case includes a facing surface facing a side surface of the cover member, the facing surface being located within a predetermined dimension from the side surface,
the case includes a recessed portion opened to the facing surface and to a front surface of the case, and the recessed portion is provided with a decorative plate having no electrical conductivity, and
in the first direction, a height dimension from an end portion positioned farthest from the antenna in the facing surface to a farthest portion positioned farthest from the antenna in the cover member is equal to or greater than 1/60 of the wavelength shortened by the cover member.

2. The electronic watch according to claim 1 , comprising:
a dial;
a drive mechanism configured to drive the hand; and
a main plate to which the drive mechanism is attached, wherein
the antenna includes a conductor element having a plate shape, the conductor element including a through hole through which the hand shaft is inserted, and
the antenna is disposed between the dial and the main plate in side view when viewed from a second direction orthogonal to the first direction.

3. The electronic watch according to claim 1 , wherein
a maximum thickness dimension of the cover member is equal to or greater than 1/30 of the wavelength shortened by the cover member.

4. The electronic watch according to claim 1 , wherein
the cover member is made of a dielectric with a relative permittivity of 6 or higher.

5. The electronic watch according to claim 1 , wherein
the decorative plate is made of a dielectric with a relative permittivity of 6 or higher.

6. The electronic watch according to claim 1 , wherein there is no metal part on a side farther from the antenna than the end portion on a same plane as the facing surface.

7. An electronic watch comprising:
a case having electrical conductivity;
a cover member attached to the case;
a hand;
a hand shaft to which the hand is attached; and
an antenna disposed so as to overlap the cover member in plan view when viewed from a first direction parallel to an axial direction of the hand shaft, the antenna being configured to receive a predetermined radio wave, wherein
the cover member is made of a material configured to shorten a wavelength of the radio wave,
the case includes a facing surface facing a side surface of the cover member and located within a predetermined dimension from the side surface, and a recessed portion opened to the facing surface and to a front surface of the case,
the recessed portion is provided with a decorative plate having no electrical conductivity, and
in the first direction, a farthest portion positioned farthest from the antenna in the cover member is positioned farther from the antenna than an end portion positioned farthest from the antenna in the facing surface.

Assignees

• Seiko Epson Corp

Inventors

• Fujisawa Teruhiko

Classifications

• H01Q9/0407

  Substantially flat resonant element parallel to ground plane, e.g. patch antenna (dipole H01Q9/285; monopole H01Q9/40) · CPC title

• H01Q1/273 Primary

  Adaptation for carrying or wearing by persons or animals · CPC title

• G04G21/04

  using radio waves (radio-controlled time-pieces G04R) · CPC title

• H01Q9/0421

  with a shorting wall or a shorting pin at one end of the element (H01Q9/0414 takes precedence) · CPC title

• H01Q7/00

  Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop · CPC title