Single-Surface Lightguide with Extended and Discrete Features
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Solution Overview
Problem
Conventional lightguides require alignment of structures on opposing sides, which complicates manufacturing and limits the use of additional coatings, while also not achieving optimal optical performance in terms of uniformity and light extraction efficiency.
Innovation Solution
A lightguide with a structured first major surface featuring extended lenticular elements and discrete light extraction features on one side, and an unstructured, optically smooth second major surface, allowing for improved angular distribution and extraction efficiency without the need for alignment, and enabling additional coatings like impact-resistant or anti-wetout coatings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If structures are placed on both opposing sides of the lightguide, then optical performance (uniformity and light extraction efficiency) is improved, but manufacturing complexity increases due to alignment requirements
Solution Approach 1:
The patent extracts the light extraction function from the opposing side structures and consolidates it onto a single major surface. The first major surface includes both extended features (for angular distribution) and discrete features (for light extraction), while the second major surface remains unstructured. This eliminates the need for alignment between opposing side structures while maintaining optical performance.
2Reliability
If structures are placed on both opposing sides of the lightguide, then light extraction efficiency is improved, but the ability to apply additional coatings is limited
Solution Approach 1:
The patent extracts all light guiding and extraction functions to the first major surface, leaving the second major surface unstructured and fully available for functional coatings. Impact-resistant coatings, anti-wetout coatings, or other functional layers can be applied to the entire second major surface without interference from opposing side structures.
3Illumination intensity
If extended features cover a large portion of the viewable area, then angular distribution is improved, but light extraction efficiency may be reduced due to limited space for discrete features
Solution Approach 1:
The patent applies local quality by creating distinct zones on the first major surface: extended features in certain regions for angular distribution control, and discrete features in other regions (spaces between extended features) for light extraction. This spatial differentiation allows each feature type to perform its optimal function without interfering with the other.
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 configuration achieves similar optical performance to conventional lightguides with structures on both sides, simplifies manufacturing, and provides an additional surface for functional coatings, enhancing light extraction and uniformity.
Implementation Method 1
The plurality of extended features extend in a first in-plane direction across at least 90 percent of an entire length L of a viewable area of the lightguide... The plurality of discrete features are disposed in spaces between the extended features
Implementation Method 2
A lightguide can be used in a backlight of a display to receive light from a light source proximate an edge of the lightguide and direct at least a portion of the received light along an output direction of the display
Data Source
AI summary
A lightguide having opposing first and second major surfaces where the first major surface includes a plurality of extended features and a plurality of discrete features is described. The lightguide has a viewable area having a length at least 100 times a thickness of the lightguide. The extended features extend in a first in-plane direction across at least 90 percent of the length L of the viewable area. The discrete features are spaced apart along the length and width of the viewable area. The discrete features may be disposed in spaces between the extended features. The discrete features may have faces extending between and connecting adjacent extended features.