Segmented Light Guide with Thermoformed Grooves for Light Leakage Prevention

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Solution Overview

Problem

Existing methods for manufacturing segmented light guides are costly and lack design flexibility, as they require optical sealing of slits cut in light guides, which can lead to light leakage and complex, costly processes.

Innovation Solution

A method involving a thermoplastic light channeling layer that is thermoformed to create grooves, which block light between segments, allowing for complex segmentation and easy integration of light sources, using materials with different glass transition temperatures for enhanced mechanical stability and flexibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If slits are cut in the light guide to create segments, then independent illumination of multiple regions is achieved, but light leakage occurs through the slits requiring complex optical sealing

Engineering Contradiction:

Improveindependent illumination capabilityVSAvoidlight leakage

Core Design Contradiction:

Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

The light guide is divided into multiple segments by creating grooves that extend from one surface to the opposite surface. These grooves physically separate the light guide into distinct illumination regions, allowing independent control of each segment while preventing light leakage between segments through the groove structures.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The groove structure acts as an intermediary element between adjacent light guide segments. The grooves are filled with a material having different refractive index than the light guide material, creating an optical barrier that mediates light transmission and prevents leakage between segments while maintaining the overall structural integrity.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If slits are cut in the light guide to create segments, then independent illumination is achieved, but additional optical sealing steps are required increasing manufacturing complexity and cost

Engineering Contradiction:

Improveindependent illumination capabilityVSAvoidmanufacturing process complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The groove formation and light blocking functions are merged into a single integrated structure. The grooves are formed as part of the light guide manufacturing process itself, combining the segmentation function with the light blocking function in one step, thereby eliminating the need for separate optical sealing operations.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The manufacturing process utilizes changes in material properties during formation. The grooves are formed by injecting material or applying pressure that causes the light guide material to flow and define the groove shapes, utilizing phase changes or viscosity variations to create the segmented structure in a single manufacturing step.

Inventive Principle:

Principle #35Parameter changes

3Adaptability or versatility

If conventional cutting methods are used to create light guide segments, then segmentation is achieved, but design flexibility is limited and manufacturing is costly

Engineering Contradiction:

Improvesegmentation capabilityVSAvoidmanufacturing flexibility

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The groove structures are formed as part of the initial light guide manufacturing process rather than as subsequent modification steps. This preliminary formation of segmentation structures allows for complex designs to be created during the base manufacturing process, enabling flexibility in final product configuration without requiring additional costly cutting or assembly operations.

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 approach simplifies the manufacturing of custom-made segmented light guides, reduces costs, and prevents light leakage between segments, enabling high design flexibility and homogeneous light distribution without the need for additional diffusers or surface textures.

Implementation Method 1

The temperature of the thermoplastic light channeling layer can be increased to a pliable forming temperature for thermoforming the at least one groove

Methodology Applied

Scientific EffectThermal heating: Heating

Implementation Method 2

the at least one groove is shaped such as to block light going from the first segment to the second segment through said groove

Methodology Applied

Scientific EffectLight blocking: Reflection

Data Source

PatentUS11474290B2Segmented light guide having light-blocking groove between segments, and a method of manufacturing

Publication Date: 2022.10.18 NEDERLANDSE ORG VOOR TOEGEPAST NATUURWETENSCHAPPELIJK ONDERZOEK TNO

AI summary

A light guide is described that includes a thermoplastic light channeling layer having at least a first segment, at least a second segment, and at least one groove dividing the thermoplastic light channeling layer into the first segment and second segment. The light guide further includes one or more light sources at least at the first segment. The at least one groove is shaped to block light from leaking between the first segment and the second segment. A method of forming the light guide is described that includes: providing a thermoplastic light channeling layer, thermoforming the at least one groove to divide the light guide into the first and second segments, and providing one of more light sources to at least the first segment.