Backlight Module Ink Layer for Mini LED Brightness Uniformity

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Solution Overview

Problem

Mini LED backlight modules experience uneven brightness due to IR drop from single-sided electric current connection, leading to higher brightness on incoming electricity sides compared to sides away from the incoming electricity sides.

Innovation Solution

A backlight module with a substrate featuring an ink layer composed of a mixture of white ink and metal oxide, where the reflectivity gradually increases from the incoming electricity side to the opposite side, and an optical film with dot structures to enhance light diffusion and concentration, addressing the uneven brightness issue.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If mini LED backlight modules use single-sided electric current connection, then wiring complexity is reduced, but brightness uniformity deteriorates due to IR drop

Engineering Contradiction:

Improvewiring complexityVSAvoidbrightness uniformity

Core Design Contradiction:

Device complexityVSIllumination intensity

Solution Approach 1:

The patent applies local quality by creating an ink layer with spatially varying reflectivity. The reflectivity of the ink layer increases from the first end (near incoming electricity side) to the second end (away from incoming electricity side), compensating for the IR drop effect and achieving uniform brightness across the backlight module while maintaining single-sided wiring

Inventive Principle:

Principle #3Local quality

2Ease of manufacture

If conventional reflection sheets are used, then manufacturing process is simple, but light utilization efficiency is low

Engineering Contradiction:

Improvemanufacturing process simplicityVSAvoidlight utilization efficiency

Core Design Contradiction:

Ease of manufactureVSUse of energy by moving object

Solution Approach 1:

The patent uses a composite ink layer made from white ink and metal oxide particles (such as titanium dioxide or aluminum oxide). This composite material provides both the reflective properties of metal oxide and the processability of ink, achieving high light utilization efficiency while maintaining ease of manufacture through printing or coating processes

Inventive Principle:

Principle #40Composite materials

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 effectively reduces light passing through the ink layer from one end to the other, overcoming uneven brightness and improving light utilization, while potentially replacing conventional reflection sheets to save production costs.

Implementation Method 1

an ink layer disposed on the substrate and having a reflectivity gradually increasing from the first end to the second end

Methodology Applied

Scientific EffectReflection: Reflection

Implementation Method 2

the optical film comprises a plurality of dot structures arranged in an array, and at least one of the light-emitting units corresponds to a center of the dot structures arranged in the array. the dot structures comprise a convex lens structure

Methodology Applied

Scientific EffectRefraction: Refraction

Data Source

PatentUS11828968B2Backlight module including optical film and manufacturing method thereof

Publication Date: 2023.11.28 TCL CHINA STAR OPTOELECTRONICS TECHNOLOGY CO LTD

AI summary

A backlight module and a method of manufacturing the backlight module are disclosed. The backlight module includes a substrate including a first end and a second end opposite to the first end. An ink layer is disposed on the substrate and has a reflectivity gradually increasing from the first end to the second end. At least two of light-emitting units are arranged in an array on the ink layer.