Light Guide Plate Micro-Structure Sets for Normal Light Emission

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Solution Overview

Problem

Conventional light source modules with light guide plates (LGP) face challenges in efficiently directing light to the normal direction due to total reflection issues, requiring additional components like prism sheets that increase costs and energy consumption.

Innovation Solution

The introduction of micro-structure sets with protrusive and recessive structures on the LGP, which are non-continuous and have specific inclined angles, effectively guide light to the normal direction without the need for prism sheets or reflective films, allowing for efficient light emission and improved brightness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If etching points or screen printed points are configured on the LGP surface to disrupt total reflection, then light can be emitted from the front surface, but the light direction deviates from the normal line requiring additional prism sheets

Engineering Contradiction:

Improvelight emission from front surfaceVSAvoidrequirement for prism sheet

Core Design Contradiction:

Illumination intensityVSDevice complexity

Solution Approach 1:

The patent applies local quality by creating micro-structures (protrusions and recesses) at specific locations on the LGP surface. These localized structural variations disrupt total reflection at precise points while maintaining smooth surfaces elsewhere, enabling light extraction without requiring additional prism sheets throughout the entire device.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent transitions from two-dimensional surface modifications (etching points, screen printed points) to three-dimensional micro-structures (protrusions and recesses with height variations). This dimensional change allows the micro-structures to effectively control light direction through their geometric configuration, eliminating the need for separate prism sheets.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Ease of operation

If prism sheets are added to correct light direction, then light can be directed to the normal line, but costs and optical energy consumption increase

Engineering Contradiction:

Improvelight direction controlVSAvoidoptical energy consumption

Core Design Contradiction:

Ease of operationVSLoss of energy

Solution Approach 1:

The patent extracts the light direction control function from a separate component (prism sheet) and integrates it directly into the LGP structure through micro-structures. By taking out the need for additional optical components and embedding the light guiding functionality within the LGP itself, the patent reduces both cost and optical energy loss.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent merges the light extraction and light direction control functions into a single integrated structure. The micro-structures on the LGP simultaneously perform both functions that were previously separated into distinct components, thereby eliminating the need for additional prism sheets and reducing overall system complexity.

Inventive Principle:

Principle #5Merging (Combining)

3Reliability

If smooth surfaces are used on the LGP, then total reflection occurs, but light cannot be emitted from the front surface

Engineering Contradiction:

Improvetotal reflection efficiencyVSAvoidlight emission from front surface

Core Design Contradiction:

ReliabilityVSIllumination intensity

Solution Approach 1:

Inventive Principle:

Principle #3Local quality

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 solution enables efficient light guidance to the normal direction, reducing the need for additional components and minimizing light loss, thus lowering costs and enhancing optical efficiency while maintaining favorable brightness.

Implementation Method 1

The micro-structure sets are separately disposed on the second surface... Each of the micro-structure sets includes at least one protrusive structure that protrudes from the second surface and at least one recessive structure that is recessed in the second surface... An inclined direction of the first micro-surface is different from an inclined direction of the second micro-surface

Methodology Applied

Scientific EffectRefraction: Refraction

Implementation Method 2

Given the surfaces of the LGP are smooth, the light entering the side of the LGP is totally reflected by the surfaces of the LGP

Methodology Applied

Scientific EffectTotal internal reflection: Total Internal Reflection

Data Source

PatentUS8764269B2Light guide plate and light source module

Publication Date: 2014.07.01 CORETRONIC CORPORATION

AI summary

A light guide plate (LGP) includes a first surface, a second surface, at least one light incident surface, and a plurality of micro-structure sets. The second surface is opposite to the first surface. The light incident surface connects the first surface to the second surface. The micro-structure sets are separately disposed on the second surface, and the micro-structure sets are not continuous in any direction parallel to the first surface. Each of the micro-structure sets includes at least one protrusive structure that protrudes from the second surface and at least one recessive structure that is recessed in the second surface. A light source module is also provided.