Variable Capacitor Terminal Member Design for Pressure Detection
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Solution Overview
Problem
Conventional variable capacitors used in writing pressure detection systems face issues such as electrode deformation due to weight, potential sticking between components, and durability problems due to point-contact abrasion, leading to inaccurate pressure detection and reduced system reliability.
Innovation Solution
A variable capacitor design featuring a dielectric member with a terminal member that acts as both an electrode and a spacer, ensuring consistent spacing and reducing the need for separate electrode formation, along with an elastic member to maintain the conductive member's distance from the dielectric member, preventing sticking and abrasion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional variable capacitor uses a separate spacer and electrode structure, then the spacing can be maintained, but the device complexity increases and manufacturing becomes more difficult
Solution Approach 1:
The patent combines the spacer function and electrode function into a single integrated terminal member. The terminal member includes both the spacer portion that maintains distance from the dielectric member and the electrode portion that provides electrical connection, eliminating the need for separate spacer and electrode components. This merging reduces device complexity while maintaining consistent spacing through the elastic biasing of the terminal member.
2Measurement precision
If the second electrode is disposed close to the dielectric member, then the capacitance increases, but electrode deformation due to weight causes measurement errors
Solution Approach 1:
The patent applies an elastic member that biases the terminal member away from the dielectric member, creating a counteracting force against the weight of the electrode structure. This elastic biasing force prevents the electrode from deforming under its own weight while maintaining a controlled, consistent spacing that enables accurate capacitance-based pressure detection without measurement errors.
3Productivity
If point-contact electrodes are used, then the device size is reduced, but abrasion at contact points reduces durability
Solution Approach 1:
The patent employs an elastic terminal member that can dynamically adjust its position and contact area with the dielectric member. Rather than a fixed point-contact, the elastic terminal member can deform to distribute contact forces, reducing abrasion at any single point while maintaining compact device dimensions. The elasticity allows the terminal member to return to its original position after contact, preventing permanent wear damage.
4Ease of manufacture
If multiple separate components are used for electrode and spacer, then the functions are clearly separated, but the manufacturing process becomes more complex
Solution Approach 1:
The patent integrates the spacer function and electrode function into a single terminal member structure. The terminal member includes a spacer portion that maintains spacing from the dielectric member and an electrode portion that provides electrical connection, eliminating the need for separate spacer and electrode components. This single-integration approach simplifies manufacturing by reducing the number of assembly steps and components while maintaining clear functional separation through the integrated design.
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 solution ensures accurate writing pressure detection, improves durability by preventing electrode degradation, and simplifies the manufacturing process by reducing fabrication steps.
Implementation Method 1
an elastic member configured to bias the conductive member in a direction in which the conductive member is spaced away from the second face portion
Implementation Method 2
a variable capacitor having a capacitance value which varies in response to external force applied thereto through the rod
Implementation Method 3
the capacitance value which varies in response to external force applied thereto through the rod
Data Source
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AI summary
A position pointer is disclosed, including a housing, a substantially bar-like rod accommodated in the housing such that one end thereof projects to the outer side of the housing, and a variable capacitor having a capacitance value which varies in response to external force applied thereto through the rod. The variable capacitor includes a dielectric member having a first face portion and a second face portion opposite from the first face portion, a terminal member configured to engage with the first face portion of the dielectric member, an electrode section disposed in an opposing relationship to the second face portion of the dielectric member and including a conductive member having a contact area with the second face portion that varies in response to the external force, and an elastic member configured to bias the conductive member in a direction in which the conductive member is spaced away from the second face portion.