Light Guide Assembly Epoxy Sealing Light Leakage

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing methods for sealing and assembling backlit display devices, such as those in motorcycle meters, face challenges in preventing light absorption by epoxy resin, which reduces illumination due to direct contact with the light guide, and require labor-intensive reflective tape application.

Innovation Solution

A light guide with smooth surfaces for light transmission and at least one surface configured for light scattering and internal reflection, coated with a reflective material to prevent epoxy contact and enhance light retention, simplifying the assembly process and ensuring robustness against dust and water penetration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If epoxy resin is used to seal and anchor the light guide and display components, then the assembly is protected against dust and liquid penetration and components are secured in place, but the epoxy absorbs light from the light guide reducing display illumination

Engineering Contradiction:

Improvesealing effectivenessVSAvoiddisplay illumination

Core Design Contradiction:

ReliabilityVSIllumination intensity

Solution Approach 1:

The light guide is divided into two distinct surface types: smooth surfaces for light transmission and textured surfaces for light scattering and reflection. This segmentation allows different surfaces to serve different functions, with textured surfaces directing light away from the epoxy while smooth surfaces maintain optical clarity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different surfaces of the light guide have different local qualities - smooth surfaces where light transmission is needed and textured surfaces where light scattering and reflection are needed. This local differentiation optimizes light management at each surface location.

Inventive Principle:

Principle #3Local quality

2Illumination intensity

If reflective tape is applied to the exterior surfaces of the light guide to prevent light absorption by epoxy, then light retention is improved, but the assembly process becomes time-consuming and labor-intensive

Engineering Contradiction:

Improvelight retentionVSAvoidassembly process

Core Design Contradiction:

Illumination intensityVSEase of manufacture

Solution Approach 1:

The light scattering and reflective functions are merged into the light guide structure itself through integral texturing, eliminating the need for separate reflective tape applications. This integration simplifies the assembly process while maintaining light retention.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The light guide structure provides its own light scattering and reflection capabilities through integral texturing, making it self-sufficient and eliminating the need for additional reflective tape components and application steps.

Inventive Principle:

Principle #25Self-service

3Illumination intensity

If reflective tape is applied to protect light guide surfaces from epoxy contact, then light leakage is prevented, but it is difficult to effectively apply tape to all surface portions of complex-shaped light guides

Engineering Contradiction:

Improvelight leakage preventionVSAvoidlight guide surface coverage

Core Design Contradiction:

Illumination intensityVSDevice complexity

Solution Approach 1:

The protective function against epoxy contact is merged with the light scattering and reflection surfaces, creating a single integrated structure that eliminates the need for separate tape applications on complex surfaces.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The light guide structure itself provides protection against epoxy contact through its textured surfaces, making the system self-protecting and eliminating the need for additional protective tape components.

Inventive Principle:

Principle #25Self-service

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 solution effectively prevents light leakage and maintains high illumination levels by protecting all light guide surfaces from epoxy contact, simplifying assembly and ensuring a robust display device without noticeable light loss.

Implementation Method 1

the light guide is a transparent glass-like solid through which light propagates from one end of the guide to another

Methodology Applied

Scientific EffectTotal internal reflection: Total Internal Reflection

Implementation Method 2

depositing on that surface a reflective coating

Methodology Applied

Scientific EffectReflection: Reflection

Data Source

PatentUS10466403B2Light guide assembly for an LCD or the like

Publication Date: 2019.11.05 POLARIS IND INC

AI summary

An apparatus and method for assembling a display device to which is coupled a light guide that has smooth surfaces for light-transmission and at least one surface that is for light scattering and internal reflection. The method includes depositing a reflective coating on that surface, and installing the display device with coupled light guide in an interior of a meter housing or casing. A portion of the casing interior is filled with a component, such as epoxy, for sealing the case interior to protect the display device and light guide against water and dust penetration. All surfaces of the light guide are protected from direct contact with the epoxy. This approach greatly simplifies the assembly process and yields a robust display that also prevents light leakage from the light guide.