LED Lens with Segmented Lateral Surface for Backlight Uniformity

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Solution Overview

Problem

Conventional backlight units for LCDs, particularly those using cold cathode fluorescent lamps (CCFLs), face issues with high power consumption, limited color gamut, and environmental pollution due to mercury content, necessitating a more efficient and cost-effective alternative.

Innovation Solution

A light emitting apparatus with a lens having a lateral surface comprising multiple segments with varying angles and RMS roughness patterns, which increases the number of optical paths for light distribution, reducing manufacturing costs, power consumption, and enabling a slimmer design for the backlight unit by using LEDs as light sources.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If CCFL is used as light source in backlight unit, then high luminance is achieved, but power consumption is high and environmental pollution occurs

Engineering Contradiction:
ImproveluminanceVSAvoidpower consumption
Core Design Contradiction:
Illumination intensityVSUse of energy by moving object

Solution Approach 1:

The patent changes the light source from CCFL to LED, fundamentally altering the energy conversion mechanism from gas discharge to electroluminescence. This parameter change achieves high luminance with significantly reduced power consumption and eliminates mercury pollution, directly resolving the technical contradiction between illumination intensity and power consumption

Inventive Principle:
Principle #35Parameter changes

2Illumination intensity

If multiple light sources are used in direct type backlight unit, then high luminance is achieved, but manufacturing cost and device complexity increase

Engineering Contradiction:
ImproveluminanceVSAvoidnumber of light sources
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

The patent merges multiple light sources into a single LED that incorporates an integrated lens with multiple optical paths. This consolidation achieves the same light distribution effect as multiple separate light sources while reducing the number of components, thereby lowering manufacturing cost and device complexity while maintaining high luminance

Inventive Principle:
Principle #5Merging (Combining)

3Illumination intensity

If conventional lens structure is used, then light distribution is provided, but manufacturing cost is high and uniformity is insufficient

Engineering Contradiction:
Improvelight distributionVSAvoidmanufacturing cost
Core Design Contradiction:
Illumination intensityVSEase of manufacture

Solution Approach 1:

The patent segments the lens into multiple distinct optical paths (first optical path, second optical path, third optical path) with different functions. This segmentation allows each path to be optimized for specific light distribution tasks while maintaining overall uniformity, and the modular structure simplifies manufacturing processes and reduces costs

Inventive Principle:
Principle #1Segmentation

4Length of moving object

If backlight unit is designed to be slim, then thickness is reduced, but light distribution uniformity and luminance may be compromised

Engineering Contradiction:
ImprovethicknessVSAvoidlight distribution uniformity
Core Design Contradiction:
Length of moving objectVSIllumination intensity

Solution Approach 1:

The patent transitions from a conventional single-direction light path to a three-dimensional multi-path optical system within the lens. By utilizing multiple optical paths that diverge in different directions (first path to first area, second path to second area, third path to third area), the lens achieves uniform light distribution across the display surface while maintaining a slim overall thickness

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 provides uniform illumination, reduces manufacturing costs, minimizes power consumption, and achieves a slimmer backlight unit design while maintaining high luminance, effectively addressing the limitations of traditional CCFL-based systems.

Implementation Method 1

a first optical path and a second optical path are provided by the lens

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 2

a first optical path and a second optical path are provided by the lens

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 3

backlight unit using light emitting diodes (LEDs)

Methodology Applied
Scientific EffectElectroluminescence: Electroluminescence

Data Source

PatentEP3015884B1Light emitting apparatus including a lens, and backlight unit including the apparatus
Publication Date: 2021.01.06 SUZHOU LEKIN SEMICON CO LTD
  • EP3015884B1 patent drawingFigure 1~2
  • EP3015884B1 patent drawingFigure 3~4A
  • EP3015884B1 patent drawingFigure 4B~4C

AI summary

A light emitting apparatus is disclosed. The light emitting apparatus includes a light source and a lens located on the light source, wherein the lens includes an upper surface, a lower surface located under the upper surface such that the lower surface is opposite to the light source, and a lateral surface connected between the upper surface and the lower surface, and wherein the lateral surface includes a plurality of segments inclined at different angles, at least one of the segments having a pattern, the pattern having root mean square (RMS) roughness including holes and rods.