Light Guide Transparent Screen Integration for Photometric Precision

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In vehicle lighting devices, especially brake lights, the dimensional manufacturing tolerances and clearance issues lead to inconsistent distances between the light guide's front part and added elements like lenses, affecting photometric functions and compromising aesthetic quality due to visible fastening means.

Innovation Solution

Integrating a transparent screen as an integral part of the support piece to which the support plate and light guide are fixed, ensuring consistent distances and eliminating the need for additional fastening elements, thus ensuring precise photometric functions and improving stylistic appearance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If an additional element (lens or screen) is added to increase illumination height, then the photometric function is improved, but manufacturing dimensional tolerances and clearances cause the distance to deviate from predefined values, worsening photometric precision

Engineering Contradiction:
Improveillumination heightVSAvoiddistance between light guide and added element
Core Design Contradiction:
Illumination intensityVSManufacturing precision

Solution Approach 1:

The patent merges the additional element (screen or lens) with the light guide by integrating it into the same molded piece. This eliminates separate fastening elements and ensures that the distance between the light guide and the screen/lens is precisely controlled by the single molding process, eliminating dimensional tolerance accumulation and clearance issues that would occur with separate components.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The light guide is designed to serve multiple functions: it acts as both the light guiding element and the structural support for the screen or lens. The light guide's front face directly supports the screen/lens, combining structural support, light guidance, and optical function into a single integrated component system.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Illumination intensity

If an additional element is added by clipping or fastening, then the illumination height is increased, but the fastening means become partially visible, worsening aesthetic quality

Engineering Contradiction:
Improveillumination heightVSAvoidaesthetic quality
Core Design Contradiction:
Illumination intensityVSShape

Solution Approach 1:

By merging the screen or lens with the light guide into a single molded piece, the patent eliminates the need for separate fastening elements. The integrated design means there are no visible clips, screws, or adhesives, resulting in a clean, seamless appearance that maintains aesthetic quality while achieving the required illumination height.

Inventive Principle:
Principle #5Merging (Combining)

3Strength

If separate fastening elements are used to attach the added element, then the assembly is secured, but the fastening means are difficult to conceal, worsening perceived quality

Engineering Contradiction:
Improveattachment securityVSAvoidperceived quality
Core Design Contradiction:
StrengthVSShape

Solution Approach 1:

The patent combines the attachment function into the molding process itself. The screen or lens is integrated into the light guide structure through co-molding or insert molding techniques, creating a permanent, secure attachment that is invisible from the outside. This eliminates the need for separate fastening elements that would compromise aesthetic quality.

Inventive Principle:
Principle #5Merging (Combining)

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 ensures consistent photometric performance by maintaining predefined distances and enhances aesthetic appeal by hiding the light guide, reducing manufacturing complexities and eliminating visible fastening issues.

Implementation Method 1

a transparent screen (ET) protruding on a second face (F2) in front of a front part (PV) of the light guide (GL)

Methodology Applied
Scientific EffectRefraction: Refraction

Data Source

PatentEP3354977B1Lighting device with light guide mounted on a supporting part incorporating a transparent magnification screen
Publication Date: 2023.05.31 STELLANTIS AUTO SAS
  • EP3354977B1 patent drawingFigure 1~2
  • EP3354977B1 patent drawingFigure 3~4

AI summary

A lighting device (ED) comprises: - a support plate (PS1) equipped with light sources (SL), - a flat type light guide (GL) having a guiding part (PG) placed between rear (PR) and front (PV) parts, the rear part (PR) supplying photons to the guiding part (PG), and the front part (PV) delivering the guided photons to the outside, and - a support piece (PS2) comprising first (F1) and second (F2) faces to which the support plate (PS1) and the light guide (GL) are fixedly attached, and a transparent screen (ET) projecting on the second face (F2) in front of the front part (PV) and extending over a height strictly greater than the thickness of the light guide (GL) in order to be backlit by the photons delivered by the front part (PV) to ensure a predefined photometric function.