Light Control Layer Structure for Windshield-Reflection Display Glare

Solution Overview

Problem

Existing display devices in vehicles face the issue of reflected light from the display device obstructing the driver's vision when light is reflected by the windshield.

Innovation Solution

A display device with a light control layer that includes transmission portions with reduced thickness and light blocking portions with reduced width, where the thickness and width of the transmission portions are determined by a function of the refractive index and exit angle of the light, effectively limiting the exit angle of light and reducing obstruction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a light control film is used to limit the exit angle of light, then driver's vision obstruction is prevented, but the display device structure becomes more complex and transmittance is reduced

Engineering Contradiction:

Improvedriver's vision obstructionVSAvoiddisplay device structure

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The light control layer is divided into multiple transmission portions and light blocking portions arranged in a specific pattern. This segmentation allows the structure to control light exit angles effectively while maintaining overall transmittance, as the transmission portions allow light passage while the light blocking portions restrict light at specific angles.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different portions of the light control layer have different optical properties - transmission portions with specific thickness and refractive index for light passage, and light blocking portions for angle restriction. This local differentiation enables precise control of light behavior at different locations within the same layer.

Inventive Principle:

Principle #3Local quality

2Object-affected harmful factors

If a light control film is used to limit the exit angle of light, then driver's vision obstruction is prevented, but light transmittance is reduced

Engineering Contradiction:

Improvedriver's vision obstructionVSAvoidlight transmittance

Core Design Contradiction:

Object-affected harmful factorsVSIllumination intensity

Solution Approach 1:

The light control layer is divided into multiple transmission portions and light blocking portions arranged in a specific pattern. This segmentation allows the structure to control light exit angles effectively while maintaining overall transmittance, as the transmission portions allow light passage while the light blocking portions restrict light at specific angles.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The thickness of transmission portions is precisely controlled within the range of 0-30 μm, and the refractive index is optimized between 1.4-1.7. These parameter optimizations enable the transmission portions to maintain high light transmittance while the light blocking portions effectively limit exit angles, achieving a balance between transmittance and angle control.

Inventive Principle:

Principle #35Parameter changes

3Illumination intensity

If the thickness of transmission portions is reduced to improve transmittance, then light transmittance is improved, but manufacturing precision requirements increase

Engineering Contradiction:

Improvelight transmittanceVSAvoidthickness control precision

Core Design Contradiction:

Illumination intensityVSManufacturing precision

Solution Approach 1:

The thickness of transmission portions is precisely controlled within the range of 0-30 μm, and the refractive index is optimized between 1.4-1.7. These parameter optimizations enable the transmission portions to maintain high light transmittance while the light blocking portions effectively limit exit angles, achieving a balance between transmittance and angle control.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The light control layer is implemented as a thin film structure with transmission portions having thickness of 0-30 μm. This thin film approach enables high light transmittance while the precise thickness control within this range ensures adequate angle control performance without requiring excessive manufacturing precision.

Inventive Principle:

Principle #30Flexible shells and thin films

4Illumination intensity

If the width of light blocking portions is reduced to improve transmittance, then light transmittance is improved, but the ability to limit exit angle deteriorates

Engineering Contradiction:

Improvelight transmittanceVSAvoidexit angle control

Core Design Contradiction:

Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

The light control layer is divided into multiple transmission portions and light blocking portions arranged in a specific pattern. This segmentation allows the structure to control light exit angles effectively while maintaining overall transmittance, as the transmission portions allow light passage while the light blocking portions restrict light at specific angles.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The thickness of transmission portions is precisely controlled within the range of 0-30 μm, and the refractive index is optimized between 1.4-1.7. These parameter optimizations enable the transmission portions to maintain high light transmittance while the light blocking portions effectively limit exit angles, achieving a balance between transmittance and angle control.

Inventive Principle:

Principle #35Parameter changes

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 display device achieves improved transmittance and reduced obstruction of the driver's vision by effectively limiting the exit angle of light, resulting in a thinner and more transparent display device.

Implementation Method 1

A thickness (T0) of each of the transmission portions and a width (S0) of each of the transmission portions in a cross-section are determined by a function of sin θ=T0/S0, wherein n is a refractive index of the transmission portions, and θ is an exit angle of a light emitted from the display panel and propagating through the light control layer

Methodology Applied

Scientific EffectRefraction: Refraction

Implementation Method 2

a light control layer that includes a transmission portion with reduced thickness and a light blocking portion with reduced width... effectively limiting the exit angle of light

Methodology Applied

Scientific EffectTotal internal reflection: Total Internal Reflection

Data Source

PatentUS12302735B2Display device and method of manufacturing the same

Publication Date: 2025.05.13 SAMSUNG DISPLAY CO LTD

AI summary

A display device includes a display panel, an optical layer disposed on the display panel, a window disposed on the optical layer, and a light control layer. The light control layer is disposed between the display panel and the optical layer or between the optical layer and the window. The light control layer includes a plurality of transmission portions spaced apart from each other and a light blocking portion filled between the transmission portions. A thickness of each of the transmission portions and a width of each of the transmission portions in a cross-section are determined by a function of a refractive index of the transmission portions, and an exit angle of light emitted from the display panel and propagating through the light control layer.