In-Vehicle Touch Panel Distance Detection for Glove Operation

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Solution Overview

Problem

In-vehicle touch panel input devices are prone to erroneous operations due to driver movements while steering, especially when wearing gloves, which can lead to safety issues and operational limitations.

Innovation Solution

An in-vehicle input device with a touch panel featuring a lower and upper electrode, a spacer with openings, and a suppression layer that detects input operations based on changes in distance rather than capacitance, allowing operation regardless of steering wheel position and glove use, using multiple detecting units for different pressure levels and operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a capacitance-based touch panel is used for in-vehicle input, then the device can be operated with a flat appearance and layout flexibility, but erroneous operations occur due to driver movement and steering wheel rotation

Engineering Contradiction:
Improvetouch panel operationVSAvoidoperation accuracy
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent changes the detection parameter from capacitance to distance measurement. The touch panel detects input operations based on distance changes between the operator's finger and the operation surface, rather than capacitance changes. This parameter change eliminates false operations caused by steering wheel rotation while maintaining ease of touch operation.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the steering wheel position is restricted to straight-ahead position for touch panel operation, then erroneous operations during steering are prevented, but the driver cannot operate the device while rotating the steering wheel

Engineering Contradiction:
Improveoperation accuracyVSAvoidoperability during steering
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent removes the steering wheel position restriction by changing the detection method to distance-based detection. The touch panel can now detect operations regardless of steering wheel position, as distance changes between the finger and operation surface occur during both intentional input and steering rotation, making the detection method adaptable to various driving conditions.

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If a driver wears gloves while operating the touch panel, then comfort is improved, but capacitance cannot be formed between the gloved finger and electrode

Engineering Contradiction:
Improvecomfort during operationVSAvoiddetection accuracy
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent changes the detection principle from capacitance-based to distance-based detection. Since distance measurement does not require direct electrical contact between the finger and electrode, operators can wear gloves for comfort while maintaining reliable detection accuracy. The system detects the distance change between the gloved finger and operation surface, eliminating the need for capacitance formation.

Inventive Principle:
Principle #35Parameter changes

4Adaptability or versatility

If the driver rotates the steering wheel to turn the vehicle, then the vehicle can be steered, but the hand and fingers move over the operation surface causing unintended operations

Engineering Contradiction:
Improvesteering capabilityVSAvoidinput accuracy
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent changes the detection method to measure distance changes between the finger and operation surface. During steering wheel rotation, the finger moves over the operation surface, but the distance to the surface remains relatively constant, so no false input is detected. This allows full steering capability while maintaining input accuracy, as the system distinguishes between intentional pressing (distance decrease) and steering movement (distance constant).

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

The device effectively reduces false operations during driving and enables reliable input regardless of steering wheel position, allowing operation with gloves, enhancing safety and usability.

Implementation Method 1

Such a touch panel input device detects an input operation based on a change in capacitance caused when an operator operating a mobile apparatus moves their finger closer to an operation surface of the input device

Methodology Applied
Scientific EffectCapacitance: Capacitance

Implementation Method 2

The suppression layer eliminates or reduces formation of a capacitance between the upper electrode and an operator

Methodology Applied
Scientific EffectCapacitance: Capacitance

Data Source

PatentEP3104261B1In-vehicle input device
Publication Date: 2020.09.16 ALPS ALPINE CO LTD
  • EP3104261B1 patent drawingFigure 1~2
  • EP3104261B1 patent drawingFigure 3
  • EP3104261B1 patent drawingFigure 4A~4B

AI summary

An in-vehicle input device (100) includes a touch panel (10) including a lower electrode (11a), an upper electrode (13a), and a spacer (12), and is capable of detecting a capacitance (C0) between the lower electrode and the upper electrode. The device has an operation surface (15a) located above the upper electrode. The operation surface includes a plurality of operation areas (15b). The spacer has a plurality of openings (12a) that coincide with the operation areas in plan view. The device further includes a suppression layer (14) that is disposed between the operation surface and the upper electrode or disposed on an upper surface of the operation surface. The suppression layer eliminates or reduces formation of a capacitance between the upper electrode and an operator. The device detects an input operation based on a change in distance between the lower electrode and the upper electrode in response to pressing any of the operation areas by the operator.