Light Guide with Asymmetric Light Source Positioning for Uniform Luminance

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Solution Overview

Problem

Conventional light emitting modules for display devices often suffer from non-uniform light luminance distribution, particularly at rounded corners, making it difficult to achieve consistent illumination.

Innovation Solution

The design incorporates a light guide with specific angular and perpendicular orientations of light-emitting surfaces and light sources, where the distance from the center of second light sources to the boundary is greater than that of first light sources, allowing for reduced light overlap and easier adjustment of luminance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If light sources are positioned at standard distances from light guide boundaries, then the structure is simple and easy to manufacture, but non-uniform light luminance distribution occurs particularly at rounded corners

Engineering Contradiction:
Improvelight luminance distribution uniformityVSAvoidlight source positioning complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies local quality by differentiating the positioning requirements for different light sources based on their locations. First light sources positioned away from rounded corners use a first distance from the boundary, while second light sources positioned near rounded corners use a second distance greater than the first distance. This localized adjustment of positioning parameters ensures uniform light luminance distribution at critical rounded corner areas without requiring complex restructuring of the entire light guide system.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent implements parameter changes by modifying the distance parameter between light sources and light guide boundaries based on position. The key parameter adjustment is setting the second distance (for light sources near rounded corners) to be greater than the first distance (for other light sources). This parameter differentiation compensates for the optical non-uniformity at rounded corners, achieving uniform light luminance distribution across the entire display area while maintaining a relatively simple overall structure.

Inventive Principle:
Principle #35Parameter changes

2Volume of moving object

If light sources are positioned closer to boundaries, then the light guide structure is more compact, but light overlap increases making luminance adjustment difficult

Engineering Contradiction:
Improvelight guide compactnessVSAvoidluminance adjustment ease
Core Design Contradiction:
Volume of moving objectVSEase of operation

Solution Approach 1:

The patent applies local quality by implementing different positioning strategies for different light sources. Light sources positioned near rounded corners (second light sources) are placed at a greater distance from the boundary compared to other light sources (first light sources). This localized positioning adjustment prevents excessive light overlap at rounded corners, enabling independent luminance control and adjustment for different regions of the display, thereby improving ease of operation for luminance adjustment.

Inventive Principle:
Principle #3Local quality

3Manufacturing precision

If light sources are positioned to achieve uniform luminance distribution, then illumination quality improves, but the positioning requirements become more stringent and complex

Engineering Contradiction:
Improvelight luminance distribution uniformityVSAvoidlight source positioning precision
Core Design Contradiction:
Manufacturing precisionVSMeasurement precision

Solution Approach 1:

The patent implements parameter changes by establishing a differentiated distance parameter system. Instead of requiring all light sources to be positioned at the same distance from boundaries, the patent specifies that second light sources near rounded corners should be positioned at a second distance that is greater than the first distance used for other light sources. This parameter differentiation simplifies the positioning precision requirements compared to more complex optimization methods, as it provides clear design guidelines that can be easily implemented and verified during manufacturing.

Inventive Principle:
Principle #35Parameter changes

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 results in substantially uniform light luminance distribution across the display device, facilitating easier adjustment and improved illumination at corners.

Implementation Method 1

a light guide, which includes a light-emitting surface, an opposite surface, a first face, a second face, and a third face

Methodology Applied
Scientific EffectLight transmission: Light

Implementation Method 2

a reflective sheet disposed in the bottom chassis to reflect light transmitted from the light guide toward the display panel

Methodology Applied
Scientific EffectLight reflection: Reflection

Data Source

PatentEP3290784A1Light emitting module and display device including light emitting module
Publication Date: 2018.03.07 SAMSUNG DISPLAY CO LTD
  • EP3290784A1 patent drawingFigure 1
  • EP3290784A1 patent drawingFigure 2
  • EP3290784A1 patent drawingFigure 3

AI summary

A light emitting module includes a light guide, a first light source, and a second light source. The light guide includes a first face, a second face oriented not parallel to the first face, a third face connected between the first face and the second face, and a light-emitting surface larger than each of the first face, the second face, and the third face. The first light source faces the first face. No light source is positioned between the first light source and an edge of the first face. The second light source faces the third face. No light source is positioned between the second light source and an edge of the third face. A distance from the second light source to the edge of the third face is greater than a distance from the first light source to the edge of the first face.