Light Guide Plate Assembly Prism Optical Coupling

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Solution Overview

Problem

Edge-type backlight illumination in liquid crystal display apparatuses suffers from low light distribution and depolarization issues due to the limitations of existing light guide plates, such as scattering dot and refractive micro groove types.

Innovation Solution

A light guide plate assembly comprising a light guide plate and an optical coupling member with prism parts that utilize total reflection to enhance light distribution and polarization efficiency, eliminating the need for additional brightness enhancement films and complex nanometer grating materials.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If scattering dot type light guide plate is used, then light can be scattered in different directions, but depolarization phenomenon occurs

Engineering Contradiction:

Improvelight distributionVSAvoidpolarization efficiency

Core Design Contradiction:

Illumination intensityVSReliability

Solution Approach 1:

The patent replaces the scattering dot mechanism with a prism-based optical coupling member that uses total internal reflection instead of scattering. This substitution maintains light distribution capability while preserving polarization efficiency by eliminating the random scattering process that causes depolarization.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the optical mechanism from scattering to total internal reflection by introducing prism parts with specific geometric parameters. This parameter change allows light to be redirected while maintaining coherent polarization, resolving the contradiction between light distribution and polarization efficiency.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If refractive micro groove type light guide plate is used, then polarization efficiency is slightly higher, but depolarization problem still exists due to deviated light paths

Engineering Contradiction:

Improvepolarization efficiencyVSAvoidlight distribution uniformity

Core Design Contradiction:

ReliabilityVSIllumination intensity

Solution Approach 1:

The patent divides the optical coupling into multiple prism parts arranged in parallel, each handling specific light paths. This segmentation allows precise control over light redirection while maintaining polarization, improving both uniformity and polarization efficiency simultaneously.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent replaces the micro groove refraction mechanism with prism-based total internal reflection. This substitution eliminates the polarization rotation effect caused by groove refraction while providing superior light distribution uniformity through controlled reflection paths.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Device complexity

If edge-type backlight illumination is used, then cost is low and panel is thin, but light distribution effect is poor

Engineering Contradiction:

Improvepanel structureVSAvoidlight distribution

Core Design Contradiction:

Device complexityVSIllumination intensity

Solution Approach 1:

The patent integrates the optical coupling member with the light guide plate into a unified assembly, nesting functional elements within each other. This nested structure achieves superior light distribution while maintaining the thin profile and low cost characteristics of edge-type backlight illumination.

Inventive Principle:

Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent changes the optical parameters of the light guide system by introducing prism parts with specific angles and refractive index characteristics. This parameter optimization improves light distribution effect while preserving the structural simplicity and cost-effectiveness of the edge-type configuration.

Inventive Principle:

Principle #35Parameter changes

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 increases light utilization and brightness uniformity, avoids depolarization, and provides more complex light paths, resulting in improved backlight illumination without additional components.

Implementation Method 1

each of the plurality of prism parts has a reflective side surface which is configured to reflect incident light incoming from the top surface towards a light exiting surface of the optical coupling member through total reflection

Methodology Applied

Scientific EffectTotal reflection: Total Internal Reflection

Data Source

PatentUS10126483B2Light guide plate assembly and display apparatus

Publication Date: 2018.11.13 BOE TECHNOLOGY GROUP CO LTD

AI summary

Embodiments of the present invention disclose a light guide plate assembly. The light guide plate assembly includes a light guide plate and an optical coupling member attached to the light guide plate. The optical coupling member includes a plate-like part and a plurality of prism parts formed on the plate-like part. Each of the plurality of prism parts has a planar top surface, the top surface engaging with a light exiting surface of the light guide plate, and each of the plurality of prism parts has a reflective side surface which is configured to reflect incident light towards a light exiting surface of the optical coupling member through total reflection. The present disclosure further discloses a display apparatus including the said light guide plate assembly.