Infrared Touch Switch Threshold Adjustment Without Manual Calibration

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Solution Overview

Problem

Existing infrared touch switches require manual sensitivity adjustment and are influenced by hardware characteristics and reflectance differences, leading to inconsistent performance and operational feeling, necessitating complex sensitivity adjustment processes and increased manufacturing and user intervention.

Innovation Solution

A sensitivity adjustment device that automatically calculates the A/D threshold value based on output data from the A/D converter, eliminating the need for manual setting and storage in nonvolatile memory, and automatically updates the threshold values to stabilize switch operation regardless of hardware characteristics and reflectance variations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If manual sensitivity adjustment is implemented using nonvolatile memory and communication tools, then sensitivity can be adjusted, but device complexity and manufacturing cost increase

Engineering Contradiction:
Improvesensitivity adjustmentVSAvoidadjustment mechanism
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The system automatically determines sensitivity thresholds by analyzing A/D conversion output data patterns without requiring manual intervention. The CPU autonomously processes the data to identify touch detection thresholds, eliminating the need for external communication tools and manual adjustment procedures.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent removes the nonvolatile memory component and communication tool requirements from the sensitivity adjustment process. By extracting these external dependencies and replacing them with automatic CPU-based analysis of A/D conversion data, the system simplifies the overall device architecture.

Inventive Principle:
Principle #2Taking out (Extraction)

2Reliability

If sensitivity adjustment parameters are stored in nonvolatile memory, then sensitivity can be maintained, but component count and cost increase

Engineering Contradiction:
Improvesensitivity maintenanceVSAvoidcomponents
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent eliminates the nonvolatile memory component from the sensitivity adjustment system. Instead of storing sensitivity parameters externally, the system maintains sensitivity information automatically through CPU-based analysis of A/D conversion output data patterns, removing the need for separate storage hardware.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The CPU performs multiple functions including data processing, threshold determination, and sensitivity maintenance without requiring dedicated hardware components. The same processing unit that analyzes A/D conversion data also determines the touch detection thresholds, consolidating functions into existing hardware.

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

3Device complexity

If fixed threshold values are used for touch detection, then device structure is simple, but operational stability varies with hardware characteristics and reflectance

Engineering Contradiction:
Improvethreshold settingVSAvoidswitch operation stability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The system transitions from fixed threshold values to dynamic threshold determination. The CPU automatically adjusts sensitivity thresholds based on real-time analysis of A/D conversion output data patterns, allowing the system to adapt to variations in hardware characteristics and environmental conditions while maintaining operational stability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system uses feedback from A/D conversion output data to automatically determine appropriate touch detection thresholds. By analyzing the patterns in the converted data, the system adjusts its sensitivity parameters based on actual operating conditions, ensuring consistent performance across different hardware variations.

Inventive Principle:
Principle #23Feedback

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 simplifies sensitivity adjustment, reduces component count and costs, and ensures stable operational feeling by automatically calculating and updating A/D threshold values, eliminating the need for manual sensitivity adjustment and reducing the impact of hardware and reflectance variations.

Implementation Method 1

the light radiated from the light emitting unit 1 is reflected by a reflector 5 such as fingers of an operator, is incident on a light receiver 6, and is converted into analog electrical signals

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Data Source

PatentEP2712088B1Sensitivity adjustment device
Publication Date: 2019.10.23 YOKOGAWA ELECTRIC CORP
  • EP2712088B1 patent drawingFigure 1
  • EP2712088B1 patent drawingFigure 2(A)~2(C)
  • EP2712088B1 patent drawingFigure 3A~3D

AI summary

A sensitivity adjustment device may include: a light receiver (6) configured to receive a reflected light that has been emitted from a light emitting unit (1) and reflected by a reflector (5), the light receiver being configured to convert the reflected light into an analog electrical signal; an A/D converter (7) configured to convert the analog electrical signal into a digital signal; a threshold value calculator (17) configured to calculate a threshold value with reference to a value of the digital signal that has been sequentially converted and output by the A/D converter; and a determination unit (16) configured to compare the value of the digital signal with the threshold value.