Light Guide Plate Pillar Structures for Downward Light Diversion

Solution Overview

Problem

Existing front light modules for transflective or reflective displays face inefficiencies in guiding light downward, leading to energy loss and interference with user viewing, along with susceptibility to scratches due to diffusion points or microstructures on the top face of light guide plates.

Innovation Solution

A front light module with pillar structures on the bottom surface of the light guide plate, made of transparent material with a higher refractive index than the light guide plate, which diverts incident light downward and enhances light intensity, implemented using common manufacturing processes to avoid interference and scratching.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If diffusion points are used on the top face of the light guide plate, then the implementation is easy, but the efficiency in guiding light downward is insufficient

Engineering Contradiction:

Improveease of implementationVSAvoidlight guiding efficiency

Core Design Contradiction:

Ease of manufactureVSLoss of energy

Solution Approach 1:

The patent inverts the conventional location of light-guiding structures from the top face to the bottom face of the light guide plate. By placing protrusions and recesses on the bottom face instead of the top face, the design achieves both improved light guiding efficiency and ease of manufacture using standard injection molding processes.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent transitions from two-dimensional diffusion points on the top surface to three-dimensional protrusions and recesses on the bottom surface. This dimensional change enables more effective light scattering and redirection while maintaining compatibility with conventional manufacturing methods.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Loss of energy

If V type microstructures are used on the top face of the light guide plate, then the efficiency in guiding light downward is improved, but the implementation is not easy

Engineering Contradiction:

Improvelight guiding efficiencyVSAvoidease of implementation

Core Design Contradiction:

Loss of energyVSEase of manufacture

Solution Approach 1:

The patent inverts the conventional location of light-guiding structures from the top face to the bottom face of the light guide plate. By placing protrusions and recesses on the bottom face instead of the top face, the design achieves both improved light guiding efficiency and ease of manufacture using standard injection molding processes.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent modifies the geometric parameters of light-guiding structures by changing their location (top to bottom face) and form (V-type to protrusion-recess pairs), enabling achievement of high light guiding efficiency through conventional injection molding rather than complex processes.

Inventive Principle:

Principle #35Parameter changes

3Loss of energy

If diffusion points or microstructures are located on the top face of the light guide plate, then the light guiding function is achieved, but they interfere with user viewing and are subject to scratches

Engineering Contradiction:

Improvelight guiding efficiencyVSAvoidviewing interference and scratch susceptibility

Core Design Contradiction:

Loss of energyVSObject-affected harmful factors

Solution Approach 1:

The patent extracts the light-guiding structures from the top face (visible surface) and relocates them to the bottom face of the light guide plate. This separation removes the harmful effects of viewing interference and scratch susceptibility while preserving the light guiding function.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent transitions from two-dimensional diffusion points on the top surface to three-dimensional protrusions and recesses on the bottom surface. This dimensional change enables more effective light scattering and redirection while maintaining compatibility with conventional manufacturing methods.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

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

Improves the efficiency of guiding light downward, providing uniform illumination while preventing interference with user viewing and reducing the risk of scratches, thus enhancing display quality.

Implementation Method 1

pillar structures on the bottom surface of the light guide plate, made of transparent material with a higher refractive index than the light guide plate, which diverts incident light downward

Methodology Applied

Scientific EffectRefraction: Refraction

Implementation Method 2

the diffused incident light hitting the diffusion points 131 indirectly (after going through a total reflection at the bottom face of the light guide plate 130)

Methodology Applied

Scientific EffectTotal internal reflection: Total Internal Reflection

Data Source

PatentUS9766389B2Display device

Publication Date: 2017.09.19 E INK HLDG INC

AI summary

A display device includes a reflective cover, a light guide plate, and a display device. The reflective cover has an opening confined by a top inner surface, at least one side inner surface, and a bottom inner surface of the reflective cover. The light guide plate has a top surface, a bottom surface, and a side face connected to the top surface and the bottom surface, a part of the top surface is covered by the top inner surface of the reflective cover. The display device is placed under the light guide plate and a partial surface of the display device is covered by the bottom inner surface of the reflective cover. The reflective cover bonds the light guide plate and the display device together.