Eyewear Sensor Module Capacitive Detection Pad Design
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Solution Overview
Problem
The existing sensor modules, such as those described in PTL 1, suffer from reduced sensitivity due to the cover member being disposed between the touch sensor and the object, resulting in a small change in capacitance upon contact.
Innovation Solution
A sensor module is designed with a capacitive detection pad and a conductive plate, where the contacted section is electrically connected to the conductive plate, and an insulating layer is disposed on the detection region of the capacitive detection pad, allowing for a miniaturized design suitable for integration into a temple of eyewear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a cover member is disposed between the touch sensor and the object, then the touch sensor is protected from damage, but the sensitivity of the sensor module deteriorates due to small capacitance change
Solution Approach 1:
The patent introduces a conductive plate as an intermediary component between the detection pad and the object. This conductive plate serves as a mediator that enhances the capacitance change when an object approaches, thereby improving sensitivity while the detection pad itself remains protected inside the casing. The conductive plate acts as the new intermediary surface that the object interacts with, rather than the detection pad directly.
2Volume of moving object
If the sensor module is miniaturized for integration into eyewear temple, then the device becomes more compact, but the detection performance may be compromised
Solution Approach 1:
The patent changes the electrical parameters of the sensor system by introducing a conductive plate with specific conductivity properties. This parameter change allows the sensor to achieve high detection sensitivity in a miniaturized form factor, as the conductive plate enhances the capacitance effect without requiring a larger physical structure. The conductive plate's electrical properties compensate for the reduced size.
3Measurement precision
If the detection pad is directly exposed to detect object contact, then the sensitivity is maximized, but the detection pad is damaged by direct contact
Solution Approach 1:
The conductive plate serves as a protective intermediary that the object contacts instead of the detection pad. This mediator maintains the electrical coupling necessary for detection while physically protecting the fragile detection pad from direct contact with objects, thus eliminating the harmful effect of damage while preserving detection sensitivity.
Solution Approach 2:
The patent segments the sensor system into distinct functional components: the detection pad (for electrical detection), the conductive plate (for object interaction and signal enhancement), and the casing (for protection). This segmentation allows each component to perform its specific function optimally without compromising the others.
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
The sensor module achieves high sensitivity for detecting object contact while preventing damage to the detection pad, and its miniaturized design allows for integration into eyewear temples.
Implementation Method 1
detect the contact of the object based on a capacitance change that occurs between the object and the touch sensor when the object comes into contact with the cover member
Implementation Method 2
The capacitor includes a top plate and a bottom plate positioned parallel to each other, and a dielectric material sandwiched between the plates
Data Source
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AI summary
Provided is a sensor module that includes: a casing; a contacted part that is disposed so that at least a part thereof is exposed to the outside of the casing and that has conductivity; and a detection part that has an electrostatic capacitance type detection pad and that is disposed inside the casing. The detection part further includes a conductive plate provided so as to correspond to the detection region of the detection pad, the contacted part being electrically connected to the conductive plate. This configuration makes it possible to provide a sensor module that is highly sensitive to contact with an object, and that prevents damage to the detection pad caused by contact with the object.