Light Guide Plate with Integrated Shielding Member

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Solution Overview

Problem

Liquid crystal display screens suffer from poor brightness and contrast due to edge light leakage and bright lines caused by light reflection from gaps between the light guide plate and plastic frame, leading to increased production costs and ineffective light shielding.

Innovation Solution

A light guide plate with a transparent substrate and a non-transparent light shielding member, integrally connected to the non-light incoming side, manufactured using injection-moulding of thermoplastic elastomeric materials, which effectively shields light leakage and improves light utilization by reflecting and reusing edge light.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a printed black edge of a diffuser is used to shield light, then light shielding is attempted, but light leakage still occurs due to gaps between the diffuser and plastic frame

Engineering Contradiction:

Improvelight leakageVSAvoidlight shielding effectiveness

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The light shielding function is extracted from the diffuser component and implemented as a separate light guide plate with an integrated light shielding layer. This separates the light diffusion function from the light shielding function, allowing the light shielding layer to directly contact the plastic frame and eliminate gaps that cause light leakage.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The light shielding layer is integrally combined with the light guide plate through injection molding, creating a unified structure. This integration ensures that the light shielding layer maintains proper positioning and contact with the plastic frame, eliminating gaps and achieving reliable light shielding without compromising the diffuser's light diffusion function.

Inventive Principle:

Principle #5Merging (Combining)

2Object-affected harmful factors

If a light guide plate with light shielding structure is used, then light leakage is prevented, but production cost increases

Engineering Contradiction:

Improveedge light leakageVSAvoidproduction cost

Core Design Contradiction:

Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

The light shielding layer and light guide plate are manufactured as an integrated single component through injection molding, eliminating the need for separate assembly steps. This integration reduces production complexity and cost while achieving effective light shielding and preventing edge light leakage.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The light shielding layer uses a non-transparent material with different optical properties than the transparent light guide plate. This parameter change in material transparency allows the same component to perform both light guiding and light shielding functions, simplifying manufacturing and reducing costs.

Inventive Principle:

Principle #35Parameter changes

3Illumination intensity

If light is reflected from the edge gap, then brightness is reduced, but contrast is also affected

Engineering Contradiction:

ImprovebrightnessVSAvoidcontrast

Core Design Contradiction:

Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

The light shielding layer converts potentially harmful edge light that would cause leakage into beneficial reflected light that is redirected back into the light guide plate. This converts what would be a loss (light leakage) into a benefit (increased light utilization and improved contrast) by reflecting edge light back into the useful light path.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

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 provides an apparent light shielding effect, preventing edge light leakage and bright lines, enhancing light utilization, and reducing production costs by ensuring total light shielding without leakage.

Implementation Method 1

the light shielding member is used to shield the light outgoing from the edge of the light guide plate

Methodology Applied

Scientific EffectLight shielding: Absorption (EM radiation)

Implementation Method 2

the light outgoing from the side edge of the light guide plate will be reflected by the edge of the plastic frame

Methodology Applied

Scientific EffectLight reflection: Reflection

Data Source

PatentUS9335461B2Light guide plate and forming mould thereof, and backlight module

Publication Date: 2016.05.10 BOE TECHNOLOGY GROUP CO LTD

AI summary

The present invention relates to the field of display technologies, and in particular, to a light guide plate, a forming mould and a backlight module. The light guide plate comprises a transparent substrate and a light shielding member, wherein the transparent substrate comprises a light outgoing surface, a bottom surface opposite to the light outgoing surface, a light incoming side and a non-light incoming side, and the light shielding member is integrally connected with the non-light incoming side of the transparent substrate. The light at the edge of the light guide plate is shielded by the non-transparent light shielding member, so that the reflection between the light and a plastic frame may be prevented effectively, and the problem may be avoided that light leakage and bright line appear at the edge of the light guide plate.