Force-Sensitive Resistor Calibration via Fastener Clamp Load
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Force-sensitive resistors in user interfaces exhibit high manufacturing variations, leading to inconsistent interpretation of input forces across devices, making mass-production assembly challenging and user input unreliable.
Innovation Solution
A method involving the use of fasteners to impart a controlled clamp load on force-sensitive elements, such as force-sensing resistors, to establish a consistent initial parameter value, compensating for manufacturing variations by adjusting the tightening torque applied to the fasteners.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If force-sensitive resistors are used in user interfaces, then input force detection is enabled, but manufacturing variations cause inconsistent interpretation of input forces
Solution Approach 1:
The patent applies parameter changes by adjusting the clamp load parameter on force-sensitive resistors through controlled fastener tightening. By varying the tightening torque to achieve desired clamp load values, the system compensates for manufacturing variations in resistor properties, ensuring consistent initial parameter values across different devices and improving input force detection reliability.
Solution Approach 2:
The patent implements feedback by measuring the actual resistance value of each force-sensitive resistor after assembly and using this information to determine the appropriate tightening torque for the corresponding fastener. This closed-loop approach ensures that each resistor achieves its target initial parameter value, compensating for manufacturing variations and improving detection consistency.
2Reliability
If manufacturing variations in force-sensitive resistors are high, then device complexity increases to compensate, but assembly difficulty increases in mass production
Solution Approach 1:
The patent applies self-service by enabling the assembly process to automatically compensate for manufacturing variations through controlled fastener tightening. The system uses simple resistance measurements and torque adjustments that can be performed during standard assembly operations, eliminating the need for complex calibration equipment or procedures while ensuring consistent device performance.
Solution Approach 2:
The patent uses parameter changes by adjusting the clamp load parameter through controlled fastener tightening. This approach allows manufacturers to compensate for resistor variations using standard assembly tools and procedures, maintaining ease of manufacture while improving reliability through consistent initial parameter values.
3Adaptability or versatility
If different force-sensitive resistors are used in different devices, then device versatility is enabled, but assembly becomes difficult due to property variations
Solution Approach 1:
The patent applies parameter changes by adjusting the clamp load parameter on force-sensitive resistors through controlled fastener tightening. By measuring actual resistor values and applying corresponding torque adjustments, the system enables consistent assembly across different devices with varying resistor properties, maintaining versatility while simplifying mass production.
Solution Approach 2:
The patent implements feedback by measuring the resistance values of force-sensitive resistors during assembly and using this information to determine the appropriate tightening torque for each fastener. This approach enables consistent assembly across different devices by compensating for resistor variations in real-time during the manufacturing process.
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
Ensures that all force-sensitive elements exhibit a desired initial parameter value, ensuring consistent interpretation of input forces across devices, facilitating reliable user input detection and overcoming assembly challenges in mass production.
Implementation Method 1
A force-sensing resistor is typically formed of a conductive polymer that exhibits a resistance that is dependent, in a predictable manner, upon the amount of force applied to a resistor surface
Implementation Method 2
Tightening of a fastener positioned in proximity to the force-sensitive element causes the fastener to exhibit a clamp load that imparts forces to the force-sensitive element
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An apparatus, and an associated method, forms a user interface permitting input of input instructions to an electronic device. Input commands are evidence by tactile input forces applied to a force receiving surface. Force sensing elements are positioned to sense indications of the tactile input force. The force sensing element is caused to exhibit a selected input parameter value through application of a selected force thereto by application of a tightening torque to a fastener positioned in proximity to the force sensing element.