Stacked Light-Guiding Plates for Thin Backlight Partial Driving

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Solution Overview

Problem

Existing display apparatuses using edge light method backlights face challenges in reducing thickness while maintaining effective partial driving and image quality.

Innovation Solution

The use of a backlight unit with multiple light-guiding plates and a bent light source substrate configuration allows for finer segmentation of light emission areas and efficient heat dissipation, reducing thickness and enhancing image quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If direct backlight is used for partial driving, then effective segmentation of light emission region is achieved, but thickness increases

Engineering Contradiction:
Improvepartial driving capabilityVSAvoidbacklight thickness
Core Design Contradiction:
Adaptability or versatilityVSLength of stationary object

Solution Approach 1:

The backlight is divided into multiple independent light emission regions by using multiple light-guiding plates, each capable of independent control. This allows partial driving functionality while maintaining a thin profile, as each plate can be selectively activated without requiring a thick direct backlight structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from a planar direct backlight approach to a stacked multi-layer configuration with light-guiding plates arranged in the thickness direction. This dimensional change enables partial driving control while reducing the overall backlight thickness by utilizing the vertical space for light guidance rather than requiring horizontal expansion.

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

2Adaptability or versatility

If multiple light-guiding plates are used for partial driving, then effective light emission segmentation is achieved, but device complexity increases

Engineering Contradiction:
Improvepartial driving capabilityVSAvoidbacklight structure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

Each light-guiding plate serves multiple functions: it guides light, enables partial driving control, and can be independently adjusted for different emission regions. This multi-functionality reduces the need for additional separate components, thereby managing complexity while achieving effective partial driving.

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

Solution Approach 2:

Multiple light-guiding plates are stacked in a nested configuration where each plate is positioned between light sources and the display panel. This nested arrangement allows multiple functional layers to be integrated within a compact vertical space, reducing overall device complexity by eliminating the need for separate control mechanisms for each region.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Length of stationary object

If light sources are positioned close to light-guiding plates, then thickness is reduced, but heat dissipation becomes difficult

Engineering Contradiction:
Improvebacklight thicknessVSAvoidheat dissipation efficiency
Core Design Contradiction:
Length of stationary objectVSTemperature

Solution Approach 1:

Heat dissipation structures such as heat sinks or thermal conductive materials are introduced as intermediary elements between the light sources and the light-guiding plates. These intermediaries conduct heat away from the closely positioned light sources without increasing the overall backlight thickness, thus maintaining both thin profile and effective heat dissipation.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces purely mechanical heat dissipation solutions (which would increase thickness) with thermally conductive material layers or integrated heat dissipation structures that utilize thermal conduction principles. This allows efficient heat management in a thin configuration by substituting mechanical spacing requirements with material-based thermal management.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 enables a thinner display apparatus with improved image contrast and quality through precise light emission control and efficient heat management.

Implementation Method 1

a light-guiding plate which guides light in a light-guiding manner

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Implementation Method 2

a wavelength conversion member that converts a wavelength of light from the light-emitting element to a displayable wavelength

Methodology Applied
Scientific EffectWavelength conversion: Fluorescence

Data Source

PatentEP3282174B1Lighting device and display device
Publication Date: 2023.10.25 SONY GROUP CORP
  • EP3282174B1 patent drawingFigure 1~2
  • EP3282174B1 patent drawingFigure 3A~3B
  • EP3282174B1 patent drawingFigure 4A~4B

AI summary

An illuminating unit includes: a light-guiding section including a plurality of light-guiding plates, in which the light-guiding plates are stacked in a thickness direction and each have a light entrance section and a light output surface; a plurality of light sources that output light toward the light entrance sections of the respective light-guiding plates of the light-guiding section; and a substrate that supports the plurality of light sources and on which a circuit section is disposed, in which the circuit section drives each of the light sources. A first portion, on which the circuit section is disposed, of the substrate is disposed in opposition to a back surface of the light-guiding section.