Switch Device Coil Antenna Offset Illumination
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Solution Overview
Problem
Existing switch devices with integrated coil antennas for smart ignition systems face challenges in achieving a compact design while maintaining flexibility in illumination for display elements and avoiding interference with the coil antenna.
Innovation Solution
The design incorporates a ring-like coil antenna with its center axis offset from the operational center line of the operation knob, allowing for a compact size and flexible illumination, with the coil antenna partially located in a through hole to prevent interference and ensure electrical connectivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the coil antenna is disposed on the radial outer side of the operation knob, then the communication function is achieved, but the outer dimension of the switch device becomes large
Solution Approach 1:
The coil antenna is positioned in the radial direction rather than extending axially outward, changing the spatial dimension of antenna placement. This allows the antenna to be integrated within the switch device's radial profile without increasing the axial outer dimension, resolving the contradiction between communication functionality and compact size.
2Length of stationary object
If the coil antenna is disposed along the inner edge of the operation knob, then the size is reduced, but the coil antenna becomes an obstacle in illumination for the display
Solution Approach 1:
The coil antenna is positioned asymmetrically in the radial direction rather than symmetrically along the inner edge. This asymmetric placement allows the display to be positioned on the operation knob without being blocked by the antenna, while still maintaining a compact overall size. The light guide path and display are arranged to be opposed to the center hole of the coil antenna, ensuring unobstructed illumination.
3Adaptability or versatility
If the center axis of the coil antenna is offset from the operational center line, then flexibility in illumination is improved, but the antenna position becomes complex
Solution Approach 1:
The offset positioning of the coil antenna serves multiple functions simultaneously: it provides the necessary radial space for display illumination, maintains compact axial dimensions, and enables proper light guide path routing. This multi-functional positioning approach increases design flexibility without proportionally increasing overall device complexity.
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 ensures a high degree of flexibility in illumination for the display while maintaining a compact size and improving communication capabilities between the coil antenna and mobile equipment.
Implementation Method 1
a ring-like coil antenna that transmits starting radio waves for activating external mobile equipment
Implementation Method 2
a coil part of a transponder in the mobile equipment generates an electromotive force, and an ID signal is transmitted to the vehicle authentication device by the electromotive force
Data Source
AI summary
A switch device includes a holder (2), an operation knob (3) that has a display and is held in the holder so as to be movable forward and rearward, a ring-like coil antenna (15), a circuit board (7) on which a detection means for detecting the operation of the operation knob is disposed, LEDs (light source) that are disposed on the circuit board and illuminate the display on the operation knob, and a slider (5) that is stored in the holder 2 so as to be movable forward and rearward integrally with the operation knob and has light guide paths for the LEDs, a center axis of the coil antenna is offset from an operational center line of the operation knob, and the light guide paths of the slider and the display on the operation knob are disposed opposed to a center hole of the coil antenna.