Backlight Module Indent Design for Hotspot Elimination

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Solution Overview

Problem

Conventional side-illuminating liquid crystal display devices experience hotspot effects due to uneven light distribution from LEDs in the backlight module, leading to poor display quality and requiring lengthy and ineffective adjustments to the light-guide plate grid design.

Innovation Solution

The method involves creating indents on the optical film of the backlight module based on simulated hotspot effects to ensure even light distribution, with the indents being strategically positioned and shaped to minimize hotspots without affecting the display area.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If the grid point design of the light-guide plate is regulated to eliminate hotspots, then the hotspot effect is reduced, but the adjustment period is long and the regulated effect is not good

Engineering Contradiction:
Improvehotspot effectVSAvoidadjustment period
Core Design Contradiction:
Object-affected harmful factorsVSLoss of time

Solution Approach 1:

The patent applies local quality by creating indents at specific locations on the optical film corresponding to the positions of individual LEDs. Instead of uniformly modifying the entire optical film or light-guide plate, the solution targets only the local areas where hotspots occur, making precise local adjustments to eliminate the harmful effect efficiently

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent employs preliminary action by using optical simulation to predict and identify hotspot locations before actual product assembly. The indents are designed and positioned in advance based on simulation results, allowing the hotspot issue to be resolved during the design phase rather than requiring lengthy field adjustments

Inventive Principle:
Principle #10Preliminary action

2Object-affected harmful factors

If the grid point design of the light-guide plate is regulated to eliminate hotspots, then the hotspot effect is reduced, but the regulated effect is not good

Engineering Contradiction:
Improvehotspot effectVSAvoidregulated effect
Core Design Contradiction:
Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

The patent applies local quality by creating indents at specific locations on the optical film corresponding to the positions of individual LEDs. Instead of uniformly modifying the entire optical film or light-guide plate, the solution targets only the local areas where hotspots occur, making precise local adjustments to eliminate the harmful effect efficiently

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent uses optical simulation as a virtual copy or model of the actual backlight module to predict hotspot locations and test different indent configurations. This allows precise optimization of the indent design before manufacturing, ensuring high manufacturing precision without requiring multiple physical prototypes and adjustments

Inventive Principle:
Principle #26Copying

3Illumination intensity

If indents are provided on the optical film to distribute incident light evenly, then light distribution is improved, but the optical film structure becomes more complex

Engineering Contradiction:
Improvelight distribution uniformityVSAvoidoptical film structure
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

The patent applies local quality by creating indents at specific locations on the optical film corresponding to the positions of individual LEDs. Instead of uniformly modifying the entire optical film or light-guide plate, the solution targets only the local areas where hotspots occur, making precise local adjustments to eliminate the harmful effect efficiently

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent segments the optical film modification into discrete, localized indents rather than applying a continuous complex structure across the entire film. Each indent is a simple geometric feature positioned at specific locations, which simplifies manufacturing while achieving the desired light distribution effect

Inventive Principle:
Principle #1Segmentation

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 approach effectively reduces or eliminates hotspots, improving display quality by distributing light evenly and maintaining the display's integrity without the need for lengthy adjustments to the light-guide plate.

Implementation Method 1

an optical film (203) attached to a side of a light emitting face (202b) of the light-guide plate (202)

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 2

making the incident light distributed evenly by providing indents for the optical film (203)

Methodology Applied
Scientific EffectScattering: Scattering

Data Source

PatentEP2881656B1Method for reducing bright spot phenomenon in a backlight module
Publication Date: 2021.04.14 BOE TECHNOLOGY GROUP CO LTD
  • EP2881656B1 patent drawingFigure 1~2
  • EP2881656B1 patent drawingFigure 3
  • EP2881656B1 patent drawingFigure 4~5

AI summary

Embodiments of the present invention disclose a backlight module and a display device and method using the same, the backlight module comprises light-guide plate, an optical film attaching to a side of a light emitting face of the light-guide plate, and a strip-like assembly of point light source disposed at the side of the light incident face of the light-guide plate, the strip-like assembly of point light source comprises point light sources toward the light incident face of the light-guide plate thereon, an edge of one side of the optical film corresponding to the light incident face of the light-guide plate is provided with indents. The backlight module could quickly and effectively eliminate hotspot effect of the backlight module.