Coated Light Pipe Assembly for Hidden 360° Vehicle Illumination

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Solution Overview

Problem

Existing vehicle lighting systems struggle to achieve uniform luminance without visible hot spots, especially when using LEDs, and often require expensive OLED technology or complex lens and reflector arrangements, which are not aesthetically pleasing or efficient.

Innovation Solution

A system featuring a lens with a transparent and/or translucent coating that hides the light source until illumination is turned on, combined with overlapping light pipes and a cladding layer for improved light reflection and distribution, achieving 360° uniform illumination.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If LED light sources are used for badge illumination, then energy efficiency and longevity are improved, but uniform luminance distribution deteriorates due to directional light emission creating hot spots

Engineering Contradiction:
Improveenergy efficiencyVSAvoiduniform luminance distribution
Core Design Contradiction:
Use of energy by moving objectVSIllumination intensity

Solution Approach 1:

A light guide member is introduced as an intermediary between the LED light source and the badge. The light guide receives directional light from the LED and redistributes it uniformly across the badge surface through its optical properties, eliminating hot spots while maintaining LED energy efficiency

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the optical parameters of the light guide member by applying a transparent and translucent coating that modifies light transmission characteristics. This coating enables the light guide to transform directional LED light into uniform diffuse illumination across the badge

Inventive Principle:
Principle #35Parameter changes

2Illumination intensity

If OLED technology is used to achieve uniform luminance, then illumination uniformity is improved, but cost and device complexity increase

Engineering Contradiction:
Improveuniform luminanceVSAvoidsystem complexity
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

Instead of using expensive OLED technology, the patent creates an optical copy or simulation of uniform illumination using a light guide member with specific coating properties. The light guide replicates the uniform luminance effect of OLEDs using simpler, more cost-effective LED technology combined with optical design

Inventive Principle:
Principle #26Copying

3Illumination intensity

If clear materials with optic features are used to diffuse light, then luminance uniformity is improved, but aesthetic appearance deteriorates because optic features are visible in unlit state

Engineering Contradiction:
Improveluminance uniformityVSAvoidaesthetic appearance
Core Design Contradiction:
Illumination intensityVSShape

Solution Approach 1:

The patent applies a transparent and translucent coating to the light guide member that changes its optical properties based on illumination state. In the unlit state, the coating appears transparent maintaining aesthetic appearance. When illuminated, the coating becomes translucent to diffuse light uniformly, achieving both aesthetic and functional requirements

Inventive Principle:
Principle #32Color changes

4Illumination intensity

If multiple light sources are used for 360° illumination, then illumination coverage is improved, but light efficiency deteriorates because light sources may stand in the path of light

Engineering Contradiction:
Improveillumination coverageVSAvoidlight efficiency
Core Design Contradiction:
Illumination intensityVSLoss of energy

Solution Approach 1:

The patent segments the illumination function by using a single light source combined with a light guide member that distributes light around the badge. This segmentation separates the light generation function from the light distribution function, achieving 360° coverage without the inefficiencies of multiple light sources

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

The system provides a hidden till lit (HTL) feature, ensuring that light sources are not visible until activated, and achieves efficient 360° illumination with uniform luminance, reducing light loss and enhancing aesthetic appeal.

Implementation Method 1

Light pipes are used in such systems to deliver the light from the light source over distances to the place of illumination. Thereby light pipes rely on total internal reflection.

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Implementation Method 2

overlapping light pipes and a cladding layer for improved light reflection and distribution

Methodology Applied
Scientific EffectLight reflection: Reflection

Data Source

PatentEP4022215B1Light assembly, vehicle design element, rear view device and door finisher
Publication Date: 2025.05.28 MOTHERSON INNOVATIONS CO LTD
  • EP4022215B1 patent drawingFigure 1
  • EP4022215B1 patent drawingFigure 2a~2c

AI summary

The present disclosure relates to a system (10, 10') comprising a light assembly for a 360° illumination of a design element, in particular configured for a vehicle design element, comprising: one or more light pipes (1, 1´), wherein each light pipe (1, 1´) comprises a core (11´), and two or more light pipes (1) and/or two end portions of one light pipe (1´) at least partially overlap, providing at least one region of overlap to substantially close a loop; one or more light sources (2, 2a, 2b, 2c, 2´), disposed at least partially within an interior of the system, wherein each light source (2, 2a, 2b, 2c, 2´) is configured to emit light (20´) based on at least receiving electrical power from an electrical power source, and each light source (2, 2a, 2b, 2c, 2´) is arranged adjacent to and directed towards at least one of the one or more light pipes (1, 1´) such that the emitted light (20´) results in reflected light (21´) propagating within the core (11´) and diffuse light (22´) exiting the one or more light pipes (1, 1´) along the same; and a lens (5´) substantially enclosing the interior, the one or more light pipes (1, 1´) and the one or more light sources (2, 2a, 2b, 2c, 2´), wherein the lens (5´), having an inner surface and an outer surface disposed opposite the inner surface, is provided with a continuous transparent and/or translucent coating on the outer surface, and with the one or more light sources (2, 2a, 2b, 2c, 2´) receiving electrical power from the electrical power source, the continuous transparent and/or translucent coating is at least partially permeable to at least some of the diffuse light (22´) which is passed through the lens (5´); wherein the continuous transparent and/or translucent coating depends on at least one characteristic of the one or more light pipes (1, 1´) and/or the one or more light sources (2, 2a, 2b, 2c, 2´), and/or the transparent and/or translucent coating comprises a metal, an alloy or a conductive metalloid, preferably providing a chromium or chromium-based reflective coating, to provide a homogenous illumination of a 360° illumination window (41´) when the one or more light sources (2, 2a, 2b, 2c, 2´) receive electrical power from the electrical power source.