Short-Wavelength Absorption Layer for UV Protection in Display Panels

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Solution Overview

Problem

In liquid-crystal display devices with a light-transmitting area, external light, particularly ultraviolet light, can degrade the liquid-crystal material, leading to reduced image quality and voltage retention ratios, especially near the imaging area where the light-transmitting area is integrated within the display area.

Innovation Solution

A short-wavelength-light absorption layer is disposed on the external light entering side of the display panel, covering the entire light-transmitting area to absorb ultraviolet light before it reaches the electrooptical substance, thereby reducing material degradation and maintaining image quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a light-transmitting area is formed in the display area to allow imaging means to receive external light, then imaging function is improved, but external light (particularly ultraviolet light) directly reaches the electrooptical substance layer causing material degradation and image quality deterioration

Engineering Contradiction:

Improveimaging functionVSAvoidelectrooptical substance stability

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

A short-wavelength-light absorption layer is introduced as an intermediary component between the light-transmitting area and the electrooptical substance layer. This intermediate layer selectively absorbs ultraviolet and short-wavelength visible light while allowing imaging functions to operate, thereby preventing direct exposure of the electrooptical substance to harmful radiation without compromising the imaging capability

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The harmful ultraviolet and short-wavelength light that would otherwise degrade the electrooptical substance is converted into a beneficial filtering mechanism. The short-wavelength-light absorption layer transforms potentially damaging radiation into absorbed energy, protecting the underlying electrooptical material while maintaining the light-transmitting function for imaging purposes

Inventive Principle:

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

2Device complexity

If the light-transmitting area is positioned inward in the display area, then device integration is improved, but the periphery display area becomes susceptible to degradation from transmitted external light

Engineering Contradiction:

Improveintegration structureVSAvoiddisplay quality uniformity

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

The light absorption function is segmented from the imaging function by introducing a dedicated short-wavelength-light absorption layer. This segmentation allows the light-transmitting area to serve dual purposes: enabling imaging while simultaneously protecting surrounding display areas through selective wavelength absorption, thus maintaining display quality uniformity across the periphery

Inventive Principle:

Principle #1Segmentation

3Device complexity

If no protective layer is added to absorb short-wavelength light, then device structure remains simple, but electrooptical substance degrades leading to stain formation and voltage retention ratio decrease

Engineering Contradiction:

Improvestructure simplicityVSAvoidultraviolet light damage

Core Design Contradiction:

Device complexityVSObject-affected harmful factors

Solution Approach 1:

Rather than applying a protective layer across the entire display area, the short-wavelength-light absorption layer is strategically positioned only in the light-transmitting area where imaging means are located. This localized approach provides targeted protection against ultraviolet damage while maintaining overall structural simplicity and avoiding unnecessary complexity in non-critical regions

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 effectively reduces the degradation of the electrooptical substance, preventing image quality deterioration and allowing for a more reliable display device with increased design flexibility, including a narrower non-display area and reduced risk of stains or burns.

Implementation Method 1

a short-wavelength-light absorption layer capable of absorbing light having a wavelength shorter than visible light is disposed on the external light entering side with respect to the electrooptical substance layer

Methodology Applied

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

Data Source

PatentUS10564479B2Display device

Publication Date: 2020.02.18 SHARP KK

AI summary

A display device includes a display panel and imaging means. The display panel includes a first substrate, a second substrate, and an electrooptical substance layer between the first and second substrates. The display panel has a first substrate side as an external light entering side and is partitioned into a display area and a non-display area. The non-display area includes a light-transmitting area through which the external light entering the display panel is transmitted toward a second substrate side of the display panel. The imaging means is disposed on the second substrate side so as to receive the external light transmitting through the light-transmitting area, and a short-wavelength-light absorption layer capable of absorbing light having a wavelength shorter than visible light is disposed on the external light entering side with respect to the electrooptical substance layer and the short-wavelength-light absorption layer extends over an entire area of the light-transmitting area.