Pressure Sensor Conductor Area Adjustment for Uniform Capacitance

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current pressure sensors in display devices face challenges in accurately detecting touch pressure due to variations in capacitance across different regions of the pressure sensing area, leading to errors in pressure recognition.

Innovation Solution

A pressure sensor design incorporating a first and second conductor with an elastic member, where the conductors form a capacitor whose capacitance changes with external pressure, and a sensor controller detects these changes, with the area of the conductors in different sensing regions adjusted to compensate for variations in deformation, ensuring uniform capacitance changes across the pressure sensing region.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If uniform conductor area is used across the pressure sensing region, then manufacturing is simplified, but pressure recognition accuracy deteriorates due to varying capacitance changes in different regions

Engineering Contradiction:
Improveconductor fabrication simplicityVSAvoidpressure recognition accuracy
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent applies local quality by varying the area of conductors in different sensing regions according to the deformation characteristics of each region. Specifically, conductors in regions with smaller deformation (typically outer regions) have larger areas, while conductors in regions with larger deformation (typically center regions) have smaller areas. This local adaptation ensures that capacitance changes remain uniform across the entire pressure sensing region, thereby improving pressure recognition accuracy without significantly complicating the manufacturing process.

Inventive Principle:
Principle #3Local quality

2Measurement precision

If conductor area is adjusted to compensate for deformation variations, then pressure recognition accuracy improves, but device complexity increases

Engineering Contradiction:
Improvepressure recognition accuracyVSAvoidconductor design complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent employs parameter changes by systematically adjusting the area parameter of conductors based on the deformation characteristics of different sensing regions. The conductor area is calculated and designed to compensate for the non-uniform deformation, ensuring that the product of conductor area and deformation (which determines capacitance change) remains substantially uniform across all regions. This approach improves pressure recognition accuracy while maintaining a relatively simple overall device structure.

Inventive Principle:
Principle #35Parameter changes

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 design minimizes errors in pressure recognition by ensuring consistent capacitance changes across the pressure sensing region, allowing for accurate detection of touch pressure intensity.

Implementation Method 1

an elastic member positioned between the first conductor and the second conductor

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

a capacitor formed by the first conductor and the second conductor, wherein a capacitance between the first conductor and the second conductor varies according to a distance between the first conductor and the second conductor

Methodology Applied
Scientific EffectCapacitance: Capacitance

Data Source

PatentEP3270268B1Pressure sensor and display device including the same
Publication Date: 2023.11.29 SAMSUNG DISPLAY CO LTD
  • EP3270268B1 patent drawingFigure 1~2B
  • EP3270268B1 patent drawingFigure 3~4
  • EP3270268B1 patent drawingFigure 5

AI summary

A pressure sensor including: a first conductor; a second conductor spaced apart from the first conductor, and positioned so as to form a capacitance with the first conductor; and an elastic member positioned between the first conductor and the second conductor, in which the capacitance varies according to a pressure applied to one or more of the first conductor and the second conductor, and the first conductor has a shape different from that of the second conductor.