Liquid-Crystal Display Local Dimming Scanner Light Guide

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Solution Overview

Problem

Conventional liquid-crystal display devices face challenges in achieving precise brightness control through local dimming while minimizing the increase in component count, as subdividing regions for improved control requires more light sources.

Innovation Solution

Incorporating a second light source and a scanner that scans the light emitted from the second source to irradiate specific regions, allowing for localized brightness control without increasing the number of first light sources, and using a reflective portion and light guide member to optimize light distribution and reduce component count.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If divided regions are further subdivided to improve brightness control precision, then brightness control precision is improved, but component count increases

Engineering Contradiction:
Improvebrightness control precisionVSAvoidcomponent count
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent divides the backlight unit into multiple emission units, each capable of independent brightness control. This segmentation allows for local dimming control where different regions of the display can have different brightness levels, improving brightness control precision without requiring to further subdivide each emission unit which would increase component count

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements dynamic brightness control by allowing each emission unit to independently adjust its emission brightness based on display content requirements. This dynamic adjustment capability enables precise brightness control for different regions while maintaining a manageable component count through shared light source infrastructure

Inventive Principle:
Principle #15Dynamics

2Measurement precision

If a second light source and scanner are added to achieve localized brightness control, then brightness control precision is improved, but device complexity increases

Engineering Contradiction:
Improvebrightness control precisionVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent introduces a scanner as an intermediary component that directs light from a second light source to specific regions. This scanner acts as a mediator between the light source and the display panel, enabling localized brightness control by selectively directing light to different emission units without requiring direct connection between each light source and every display region

Inventive Principle:
Principle #24Intermediary (Mediator)

3Adaptability or versatility

If multiple light sources are disposed in each divided region for local dimming control, then local dimming control capability is improved, but device complexity increases

Engineering Contradiction:
Improvelocal dimming control capabilityVSAvoiddevice complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent designs emission units that can serve multiple functions: they can be individually controlled for local dimming, they can collectively provide full-backlight illumination, and they support both laser-diode and LED light source types. This multi-functionality enables versatile local dimming control while avoiding the need for separate dedicated light sources for each function, thereby reducing overall device complexity

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

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 enhances precision in brightness control while maintaining a reduced component count, enabling efficient and precise local dimming without the need for additional first light sources, and improves installation efficiency by allowing simultaneous installation of scanning units.

Implementation Method 1

a scanner that scans a light emitted from the second light source to the face on the opposite side of the display face

Methodology Applied
Scientific EffectLight scanning:

Implementation Method 2

a reflective portion that reflects a light from the first light source to a display side

Methodology Applied
Scientific EffectLight reflection: Reflection

Data Source

PatentEP3407126B1Liquid-crystal display device
Publication Date: 2021.06.09 FUNAI ELECTRIC CO LTD
  • EP3407126B1 patent drawingFigure 1
  • EP3407126B1 patent drawingFigure 2~3
  • EP3407126B1 patent drawingFigure 4~5

AI summary

A liquid-crystal display device has a display (1) that includes a display face (1a), a plurality of first light sources (4), each of which emits a first light to a face (1b) on an opposite side of the display face (1a), a second light source (5a) that differs from the first light source (4) and emits a second light, and a scanner (5b) that scans the second light in the face. The scanner scans the second light in a predetermined region within a region to which the first light is irradiated. The second light overlaps the first lights in the predetermined region.