Capacitive Input Sensing with Fast Element Data Convergence

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Solution Overview

Problem

Existing input devices require repetitive data generation processes to achieve accurate element data, increasing computational load and complexity, especially when detecting multiple contact positions on an operation surface.

Innovation Solution

An input device that generates element data indicating the degree of proximity of an object to multiple sections on an operation surface using a sensor and an element data generator, which calculates and corrects tentative values based on detection data from fewer detection regions, simplifying calculations by repeating the data generation process at least twice and using predetermined percentages to converge on convergence values.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the data generation process is repeated multiple times to improve accuracy, then the accuracy of element data increases, but the computational load increases

Engineering Contradiction:
Improveaccuracy of element dataVSAvoidcomputational load
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent pre-calculates and stores the relationship matrix between detection regions and sections before actual measurement. This preliminary preparation allows the system to quickly generate element data from detection data without requiring repeated iterative calculations during operation, thus improving accuracy while reducing computational load during the measurement phase.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent creates a mathematical model (relationship matrix) that copies and represents the complex relationship between detection regions and sections. This model allows the system to generate accurate element data through simple matrix operations rather than repeated complex calculations, reducing computational load while maintaining measurement precision.

Inventive Principle:
Principle #26Copying

2Device complexity

If the number of detection regions is reduced to simplify the sensor configuration, then the device complexity decreases, but the ability to detect multiple contact positions accurately deteriorates

Engineering Contradiction:
Improvesensor configuration complexityVSAvoiddetection accuracy of multiple contact positions
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent divides the operation surface into multiple detection regions and further segments each detection region's contribution to multiple sections using a relationship matrix. This segmentation allows a smaller number of detection regions to accurately represent multiple sections by distributing detection data appropriately, reducing device complexity while maintaining detection accuracy.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent makes each detection region serve multiple sections simultaneously through the relationship matrix. Each detection region's data is distributed to multiple sections according to predetermined percentages, allowing fewer detection regions to provide information for multiple sections, thus reducing device complexity while preserving the ability to detect multiple contact positions accurately.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Measurement precision

If the number of electrodes is increased to improve detection resolution, then the measurement precision improves, but the device complexity and manufacturing cost increase

Engineering Contradiction:
Improvedetection resolutionVSAvoidnumber of electrodes
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent transitions from a physical dimension solution (increasing the number of electrodes) to a mathematical dimension solution (using a relationship matrix with predetermined percentages). This allows the system to achieve high detection resolution by virtually dividing sections and distributing detection data mathematically, rather than physically increasing the number of electrodes, thus improving measurement precision while reducing device complexity.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 approach allows for the generation of element data with reduced computational load and increased accuracy by simplifying the data generation process, enabling efficient detection of object proximity across multiple sections with fewer detection regions.

Implementation Method 1

an image sensing method that can simultaneously detect multiple contact positions is typically used. Methods for detecting changes in capacitance include a mutual-capacitance method where changes in capacitance between two electrodes are detected and a self-capacitance method where capacitance between an electrode and a ground is detected.

Methodology Applied
Scientific EffectCapacitance: Capacitance

Data Source

PatentEP3508957B1Input device, element data configuration method and program
Publication Date: 2021.09.22 ALPS ALPINE CO LTD
  • EP3508957B1 patent drawingFigure 1
  • EP3508957B1 patent drawingFigure 2~2B
  • EP3508957B1 patent drawingFigure 3

AI summary

A data generation process is repeated at least two times. A value approximate to the convergence value of element data is calculated for each of M sections A1 through AM by obtaining a difference between a first tentative value (PAjt=1) of element data obtained in the first data generation process and a second tentative value (PAjt=2) obtained in the second data generation process, multiplying the difference by a proportionality coefficient γ, and adding the multiplied difference to the first tentative value (PAjt=1). Compared with a configuration where the data generation process is repeated a large number of times to obtain the convergence value of element data, the above configuration makes it possible to greatly reduce the number of times the data generation process is repeated.