Light Sensing Contact Activation for Vehicle HMI

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Solution Overview

Problem

Conventional touch screens in motor vehicles often leave fingerprints, leading to cleanliness issues and potential distractions, especially in ride-sharing scenarios, which can affect performance.

Innovation Solution

A human machine interface with light sensing contact activation, featuring a transparent or translucent substrate with chromium-based reflective coating and optical waveguides, allowing for touch activation without physical contact, thus reducing fingerprint contamination.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a conventional touch screen is used for vehicle control, then the interface is easy to operate, but fingerprints are left on the display causing cleanliness issues and potential distractions

Engineering Contradiction:

Improvetouch activationVSAvoidfingerprint contamination

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent replaces direct mechanical contact (finger touching the screen) with optical sensing (ToF sensor detecting light reflection changes). The system uses a light source and sensor to detect finger proximity and touch gestures through optical means, eliminating the need for physical contact with the display surface while maintaining touch activation functionality.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces an optical intermediary system consisting of a light source, optical waveguide, and ToF sensor that mediates between the user's finger and the display screen. This intermediary optical path allows touch detection without direct contact, as the light reflects off the finger and is detected by the sensor through the waveguide, preventing fingerprint deposition on the screen.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Illumination intensity

If a transparent substrate with chromium coating is used, then the display maintains visibility and aesthetic appearance, but the coating may interfere with light transmission

Engineering Contradiction:

Improvedisplay visibilityVSAvoidlight transmission for sensing

Core Design Contradiction:

Illumination intensityVSReliability

Solution Approach 1:

The patent applies the chromium-based reflective coating selectively to specific regions of the substrate rather than uniformly across the entire surface. The coating is applied to areas where structural support and aesthetic appearance are needed, while leaving other areas transparent or translucent to allow optimal light transmission for the ToF sensing function. This localized application resolves the conflict between visibility/aesthetics and light transmission reliability.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent modifies the optical parameters of the substrate by using transparent or translucent materials with specific light transmission characteristics. The chromium coating thickness and reflectivity are optimized to balance visual appearance with light transmission requirements for the optical sensing system, allowing the display to remain visible while enabling sufficient light passage for accurate touch detection.

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 interface allows for clean and reliable activation of vehicle functions without leaving fingerprints on the display, maintaining a clean appearance and enhancing user safety by preventing distractions.

Implementation Method 1

at least one optical waveguide for guiding the transmission signals from the ToF sensor to at least one deflection point

Methodology Applied

Scientific EffectOptical waveguide: Waveguide (optics)

Implementation Method 2

at least one Time-of-Flight (ToF) sensor for emitting transmission signals in the form of light, receiving reception signals

Methodology Applied

Scientific EffectTime-of-Flight sensing: Time of Flight

Implementation Method 3

receiving reception signals deflected at the object

Methodology Applied

Scientific EffectLight reflection: Reflection

Data Source

PatentUS11400813B2Human machine interface with light sensing contact activation

Publication Date: 2022.08.02 MOTHERSON INNOVATIONS CO LTD

AI summary

A human machine interface with light sensing contact activation includes an operating panel and a display unit, where the operating panel includes at least one or more of a transparent or translucent substrate provided with at least one key area and at least one illumination source which can emit light into the substrate, and the display unit provides at least one information section at least temporarily displaying information on at least one function, which can be contact activated via the at least one key area of the operating panel. A rearview device and a motor vehicle may include such a human machine interface.