Touch Sensor Sensitivity Switching for In-Vehicle False Touch Prevention

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

False detection of touch sensors due to objects hanging from rearview mirrors in vehicles, such as good luck charms or accessories, which are swayed by automobile vibrations, cannot be prevented through calibration, leading to increased sensitivity and false touch detection.

Innovation Solution

A touch detection system with non-visible light sources emitting upward and photodetectors to distinguish between an operator's hand and hanging objects by analyzing reflected light intensity and frequency, adjusting touch sensitivity accordingly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the sensitivity of the touch panel is increased to detect touches accurately, then touch detection accuracy is improved, but false detection due to noise or suspended objects increases

Engineering Contradiction:
Improvetouch detection accuracyVSAvoidfalse detection rate
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent introduces an intermediary object (transparent sheet with light-transmitting holes) between the light source and touch panel. This intermediary structure allows light to pass through specific regions while blocking other areas, enabling the system to distinguish between actual touches and false triggers from suspended objects. The light-transmitting holes act as a spatial filter that mediates between the proximity detection function and false detection prevention.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent applies local quality by creating regions with different light transmission properties. The transparent sheet has light-transmitting holes at specific positions where touches should be detected, while other regions block light to prevent false detection from suspended objects. This local differentiation allows the system to have high sensitivity where needed while maintaining reliability in other areas.

Inventive Principle:
Principle #3Local quality

2Measurement precision

If calibration is performed to set detection characteristics for fixed objects, then detection accuracy for fixed objects is improved, but detection of swaying suspended objects remains unreliable

Engineering Contradiction:
Improvedetection characteristic accuracyVSAvoiddetection adaptability to moving objects
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent employs dynamics by making the light blocking adaptive rather than fixed. The transparent sheet with light-transmitting holes creates a dynamic detection zone that can accommodate the movement and swaying of suspended objects. Instead of relying on static calibration, the system dynamically defines detection regions through the physical structure of the light-transmitting holes, allowing it to adapt to moving objects without requiring recalibration.

Inventive Principle:
Principle #15Dynamics

3Measurement precision

If light sources are arranged to detect proximity in front of the display, then proximity detection capability is improved, but detection of suspended objects hanging from rearview mirror increases

Engineering Contradiction:
Improveproximity detection capabilityVSAvoidfalse proximity detection from suspended objects
Core Design Contradiction:
Measurement precisionVSObject-generated harmful factors

Solution Approach 1:

The patent applies segmentation by dividing the detection space into distinct regions using the transparent sheet with light-transmitting holes. The light sources are segmented into multiple individual sources arranged horizontally, and the transparent sheet segments the detection zones accordingly. This segmentation allows the system to detect proximity in valid regions while excluding suspended objects from specific detection zones, preventing false detection while maintaining useful proximity detection capability.

Inventive Principle:
Principle #1Segmentation

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

Effectively prevents false touch detection by differentiating between an operator's hand and hanging objects, ensuring accurate touch sensitivity adjustment.

Implementation Method 1

three or more light sources, arranged below the lower edge of the display surface of the display in a horizontal direction of the display, and configured to emit non-visible light upward in a direction toward a space in front of the display surface, photodetectors, each configured to detect a reflected light of the non-visible light emitted by a corresponding one of the light sources

Methodology Applied
Scientific EffectLight reflection: Reflection

Implementation Method 2

capacitive touch panel

Methodology Applied
Scientific EffectCapacitance: Capacitance

Data Source

PatentEP4711902A1Touch detection system
Publication Date: 2026.03.18 ALPS ALPINE CO LTD
  • EP4711902A1 patent drawingFigure 1
  • EP4711902A1 patent drawingFigure 2A~2B
  • EP4711902A1 patent drawingFigure 2C

AI summary

A touch detection system includes a display, touch sensors arranged below a lower edge of a display surface of the display, light sources, photodetectors to detect a reflected light of the non-visible light emitted by the light source, a touch detector to detect a touch on the touch sensors with a set detection sensitivity, and a proximity detector to detect proximity of a hand to a region below the lower edge of the display surface, wherein the proximity detector detects the proximity of the hand to the region when a predetermined condition is satisfied, and when the proximity of the hand to the region is detected, the touch detector sets the detection sensitivity of the touch detector to a first sensitivity, and otherwise, the touch detector sets the detection sensitivity of the touch detector to a second sensitivity, which is less sensitive than the first sensitivity.