Optical Film Side Blocking Layer for Quantum Dot Blue Ring Suppression

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Solution Overview

Problem

Conventional optical films used in display devices suffer from unwanted excitation of quantum dots due to incident blue light entering through side surfaces, leading to undesired light mixture and image quality degradation, manifesting as a blue ring or halo.

Innovation Solution

An optical film with a blocking layer bonded to its side surface to prevent blue light from entering the working layer, combined with a light emitting unit that emits blue light to excite quantum dots, producing white light through the main surfaces, while the blocking layer absorbs or reflects blue light and prevents moisture ingress.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If the optical film uses quantum dots to generate white light through blue light excitation, then the color levels and chromaticity are improved, but blue light entering through the side surface causes unwanted excitation and degrades image quality

Engineering Contradiction:

Improvecolor levelsVSAvoidblue ring or halo

Core Design Contradiction:

Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

The optical film is segmented into distinct functional layers: a working layer containing quantum dots for light conversion, and a blocking layer specifically positioned at the side surface to intercept blue light. This segmentation allows the film to simultaneously achieve wide color gamut through quantum dot excitation while preventing side-surface blue light intrusion that causes blue ring artifacts.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A blocking layer acts as an intermediary element between the external environment and the quantum dot working layer. This blocking layer, positioned at the side surface, selectively intercepts blue light before it can enter the working layer, thereby preventing unwanted excitation of quantum dots and the subsequent blue ring artifact without interfering with the intended light conversion function.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Manufacturing precision

If the blocking layer is added to prevent blue light entry, then image quality is improved, but the device structure becomes more complex

Engineering Contradiction:

Improveimage qualityVSAvoidstructure

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The blocking layer is merged with the side surface of the optical film to form an integrated structure. Rather than being a separate component, the blocking layer is positioned and bonded directly to the side surface, creating a unified optical element that prevents blue light entry while maintaining structural simplicity and avoiding the need for additional separate parts.

Inventive Principle:

Principle #5Merging (Combining)

3Reliability

If the blocking layer is applied to the side surface, then blue light entry is prevented, but the manufacturing process becomes more difficult

Engineering Contradiction:

Improveimage qualityVSAvoidmanufacturing process

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The blocking layer is implemented as a thin film structure that can be conformally applied to the side surface of the optical film. This thin film approach allows for effective blue light blocking while maintaining flexibility in the manufacturing process, enabling the blocking layer to be integrated during standard film lamination or coating operations without requiring complex assembly steps.

Inventive Principle:

Principle #30Flexible shells and thin films

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 minimizes blue ring or halo issues, enhances image quality by preventing unwanted light mixture and maintains module reliability by blocking moisture, thereby improving viewer satisfaction and display performance.

Implementation Method 1

The working layer includes a plurality of quantum dots that are capable of being excited by a first light incident on the light incident surface to emit a second light having a wavelength greater than that of the first light

Methodology Applied

Scientific EffectPhotoluminescence: Photoluminescence

Implementation Method 2

The blocking layer is bonded to the side surface so as to block the first light from entering the working layer through the side surface

Methodology Applied

Scientific EffectAbsorption (EM radiation): Absorption (EM radiation)

Data Source

PatentUS10156343B2Optical film and lighting module including the same

Publication Date: 2018.12.18 EFUN TECH CO LTD

AI summary

An optical film includes a blocking layer, and a main body unit including first and second base layers, a working layer and a side surface. The first base layer has a light incident surface and a first surface opposite to the light incident surface. The second base layer has a second surface facing the first surface and a light exiting surface opposite to the second surface. The working layer is interconnected between the first and second surfaces, and includes a plurality of quantum dots, which can be excited by a first light incident on the light incident surface to emit a second light. The side surface surrounds the light incident, first, second and light exiting surfaces. The blocking layer is bonded to the side surface.