Vehicle Control Module Light Leakage Reduction

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Solution Overview

Problem

The existing control and display modules in motor vehicles suffer from unwanted light leakage due to diffuse light sources and imperfections in the touch screen, leading to distracting and reduced qualitative user experience, especially at night.

Innovation Solution

The implementation of means to limit or eliminate incident rays with angles inducing partial or total reflection inside the transparent touch screen, positioned between the light source and the touch screen, such as orientation means with prismatic sections or opaque blades, to redirect and re-collimate light rays, ensuring homogeneous and controlled lighting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If a diffuse light source is used to illuminate the touch control zones, then the control zones can be viewed during day or night driving, but light leakage occurs inside the transparent touch screen causing disturbing lighting

Engineering Contradiction:
Improveillumination of control zonesVSAvoidlight leakage
Core Design Contradiction:
Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces an intermediary optical element (prismatic layer or light guide) between the diffuse light source and the touch screen to redirect light rays. This intermediary component modifies the light path by refracting and reflecting rays at controlled angles, preventing them from entering the touch screen at angles that would cause total internal reflection and light leakage, while still providing sufficient illumination to the control zones.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the angular distribution parameter of the light source by using optical elements with specific refractive indices and prismatic geometries. By controlling the incident angle of light rays through these optical parameters, the system transforms the broad angular distribution of diffuse light into a more directed pattern that illuminates control zones effectively while avoiding the critical angle for total internal reflection in the touch screen.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If opaque film with transparent pictograms is added to the touch screen, then control buttons can be viewed during day or night, but light rays with strong inclination cause total reflection inside the touch screen

Engineering Contradiction:
Improvevisibility in different lighting conditionsVSAvoidlight reflection
Core Design Contradiction:
Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The patent places an optical redirecting element as an intermediary between the light source and the opaque film with pictograms. This element acts as a mediator that selectively directs light rays toward the control zones while preventing inclined rays from reaching the touch screen at angles that would cause total internal reflection, thereby reducing energy loss while maintaining visibility adaptability.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent applies preliminary action by pre-modifying the light ray distribution before the light reaches the touch screen and opaque film. The optical elements (prismatic layers or light guides) are positioned to redirect light paths in advance, ensuring that only appropriately angled rays illuminate the control zones and pictograms, preventing the formation of problematic reflected rays before they can cause energy loss.

Inventive Principle:
Principle #10Preliminary action

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 solution effectively minimizes parasitic light energy, enhancing the qualitative user experience by reducing unwanted light leakage and maintaining sufficient illumination for control zones, thus improving the perception of the control and display module.

Implementation Method 1

a light source (27) for illuminating the touch control zone (25), the diffuse light beam (32) formed by the light source (27) being guided in a light box (31)

Methodology Applied
Scientific EffectLight propagation: Light

Implementation Method 2

limiting or even eliminating the incident rays arriving on the transparent plate (34) with an incident angle inducing a reflection partial or total inside the transparent plate of the touch screen

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Implementation Method 3

incident rays 12i arrive at the interface of the touch screen 3 (forming a first diopter) with an angle of incidence such that the refracted rays 12r inside the touch screen have a greater angle

Methodology Applied
Scientific EffectRefraction: Refraction

Data Source

PatentEP2694317B1Control and display module for a motor vehicle
Publication Date: 2019.05.15 VALEO SYST THERMIQUES SAS
  • EP2694317B1 patent drawingFigure 1a~1b
  • EP2694317B1 patent drawingFigure 2
  • EP2694317B1 patent drawingFigure 3

AI summary

The present invention relates to a control and display module, comprising: a plate made of a transparent material and comprising a top surface and a bottom surface; a light source capable of emitting a light beam and illuminating said bottom surface of said transparent plate. The module further comprises a means which is positioned between said transparent plate and said light source, and which is capable of minimizing the amount of interfering light energy emitted from said light source, and of inducing a leakage luminous flux by reflecting the luminous flux into the body of said transparent plate.