Ring-Shaped Bezel Antenna for Compact Electronic Timepiece
Solution Overview
Problem
Conventional electronic timepieces with integrated antennas face design constraints due to the need for large antennas and metal dials, resulting in bulky devices that limit material and arrangement options.
Innovation Solution
A cylindrical electronic timepiece design featuring a ring-shaped bezel with an inward flange and a transparent dielectric windshield member, where the relative permittivity and overlap area of the windshield member with the bezel are adjusted to resonate with desired radio frequencies, allowing the bezel to function as an antenna without increasing the device's size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the antenna is arranged on the dial to receive radio waves, then the antenna can be integrated into the timepiece, but the timepiece becomes thick and large
Solution Approach 1:
The patent transitions the antenna arrangement from a two-dimensional planar layout on the dial to a three-dimensional configuration utilizing the space between the dial and windshield member. This vertical dimensionality change allows the antenna to achieve adequate reception area without increasing the horizontal footprint of the timepiece case.
Solution Approach 2:
The patent employs a flexible printed circuit board (FPC) as the antenna substrate, which can be bent and shaped to fit the confined space between the dial and windshield member. This flexible film approach enables the antenna to achieve adequate area for radio wave reception while conforming to the limited available volume.
2Reliability
If a large antenna is used to receive radio waves of desired frequency, then the antenna gain is improved, but the timepiece case becomes large
Solution Approach 1:
The patent utilizes the vertical space between the dial and windshield member to create an effectively larger antenna area without increasing the horizontal case dimensions. By stacking the antenna structure in the thickness direction, the antenna achieves adequate area for desired frequency reception while maintaining a compact case footprint.
Solution Approach 2:
The antenna is nested within the existing structure of the timepiece, specifically in the space between the dial and windshield member. This nested configuration allows the antenna to occupy unused internal volume rather than requiring additional external space, thereby maintaining compact case dimensions while achieving adequate antenna area.
3Device complexity
If the dial is used as ground for the antenna, then the antenna structure is simplified, but the dial material must be metal which limits design choices
Solution Approach 1:
The patent extracts the ground function from the dial and assigns it to a dedicated ground electrode on the FPC. This separation allows the dial to serve purely as a display element without being constrained by electrical conductivity requirements, enabling the use of non-metallic dial materials while maintaining the antenna's electrical structure.
Solution Approach 2:
The FPC acts as an intermediary between the antenna element and the ground, providing a dedicated ground path through its ground electrode. This intermediary structure eliminates the need for the dial to function as ground, thereby decoupling the dial's material selection from electrical conductivity requirements while maintaining the antenna's electrical integrity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration enables the reception of radio waves with desired frequencies, such as those from GPS and GLONASS satellites, while maintaining a compact design and improving antenna gain, thus enabling accurate time and position information acquisition.
Implementation Method 1
the bezel is configured to resonate with a radio wave having a desired frequency by adjustment of at least one of (i) a relative permittivity of the dielectric substance which forms the windshield member and (ii) an area of an overlap region where the inward flange part and the windshield member overlap each other
Data Source
AI summary
An embodiment of an electronic timepiece includes a cylindrical exterior case, a bezel and a windshield member. In the exterior case, a circuit board is housed. The bezel is formed of a metal material to be ring-shaped, includes an inward flange part that projects from an inner side surface toward a center of the ring-shaped bezel, is arranged on an outer upper side of the exterior case and is electrically connected with the circuit board. The windshield member is formed of a transparent dielectric substance, arranged in the bezel and supported by the inward flange part. The bezel is configured to resonate with a radio wave having a desired frequency by adjustment of at least one of (i) a relative permittivity of the dielectric substance and (ii) an area of an overlap region where the inward flange part and the windshield member overlap each other.