Backlight Unit Reflector Design for LCD Luminance Uniformity

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional backlight units for LCDs, particularly those using CCFLs, face issues such as high power consumption, low color reproduction efficiency, and environmental concerns due to mercury usage, while LED-based units are expensive and limited to high-end products due to complex driving mechanisms.

Innovation Solution

A backlight unit design incorporating a first and second reflector with a third reflector between adjacent light sources, optimized for uniform luminance, which includes a light source module with LEDs, a lens, and a reflective structure to enhance light distribution and reduce hot spots, allowing for efficient light emission and reduced power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If CCFLs are used as light sources in backlight units, then high luminance can be achieved, but power consumption increases and environmental pollution occurs due to mercury usage

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 operating parameters including power consumption, lifespan, and environmental impact while maintaining backlight illumination function

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent adopts LED technology which, although having longer lifespan, replaces the expensive and environmentally harmful CCFL system with a more cost-effective and sustainable solution, aligning with the trend of replacing short-lived harmful components with durable eco-friendly alternatives

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

2Illumination intensity

If CCFLs are used as light sources in backlight units, then high luminance can be achieved, but environmental pollution occurs due to mercury usage

Engineering Contradiction:
ImproveluminanceVSAvoidenvironmental pollution
Core Design Contradiction:
Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

The patent eliminates the harmful mercury-containing CCFLs and replaces them with LED technology that produces no harmful emissions, converting the harmful backlight system into an environmentally benign one while maintaining illumination performance

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent replaces environmentally harmful components (mercury-based CCFLs) with eco-friendly LED alternatives, following the principle of eliminating substances that cause environmental pollution

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Use of energy by moving object

If LEDs are used in backlight units, then power consumption is reduced and color reproduction is improved, but device complexity increases due to expensive drivers and PCBs

Engineering Contradiction:
Improvepower consumptionVSAvoiddriving mechanism complexity
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The patent merges the LED chip and lens into a single integrated component, eliminating the need for separate driver circuits and PCBs that were required in conventional LED backlight designs, thereby reducing device complexity

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The integrated LED-lens component performs multiple functions simultaneously: light emission, light shaping, and structural support, replacing what previously required multiple separate components including drivers and mounting structures

Inventive Principle:
Principle #6Universality (Multi-functionality)

4Ease of manufacture

If conventional backlight units without third reflector are used, then manufacturing is simpler, but luminance uniformity deteriorates due to hot spots between adjacent light sources

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidluminance uniformity
Core Design Contradiction:
Ease of manufactureVSStability of the object's composition

Solution Approach 1:

The patent divides the reflective surface into multiple segments: first reflectors adjacent to each light source, second reflectors at the edges, and third reflectors positioned between adjacent light sources. This segmentation allows each reflector to control light distribution in its specific zone, achieving uniform overall luminance

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies different reflector configurations to different spatial zones: third reflectors are specifically positioned in the regions between light sources where hot spots occur, while first and second reflectors handle light distribution in other areas, providing localized correction where needed

Inventive Principle:
Principle #3Local quality

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 design achieves uniform luminance and reduced power consumption, making it suitable for a wider range of LCD applications while being environmentally friendly, and potentially lowering production costs by simplifying the driving mechanism.

Implementation Method 1

a first reflector, a second reflector partially having an inclined surface, a plurality of light sources disposed between the first reflector and the second reflector, and a third reflector disposed between adjacent light sources

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP2458430B1Backlight unit and display apparatus using the same
Publication Date: 2021.04.21 SUZHOU LEKIN SEMICON CO LTD
  • EP2458430B1 patent drawingFigure 1A~1B
  • EP2458430B1 patent drawingFigure 1C
  • EP2458430B1 patent drawingFigure 2A~2B

AI summary

A backlight unit and a display apparatus using the same are disclosed. The backlight unit includes a first reflector, a second reflector partially having an inclined surface, a plurality of light sources disposed between the first reflector and the second reflector, and a third reflector disposed between adjacent light sources.