Optical Laminate Axis Configuration for Asymmetric Vehicle Display Luminance

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Solution Overview

Problem

Existing image display apparatuses struggle to achieve high luminance in the front direction while maintaining asymmetrical luminance in directions tilted from the front, particularly in vehicle applications, where visibility from the passenger seat is desired but glare on the windshield is minimized.

Innovation Solution

An optical laminate comprising specific layers of light absorption anisotropic and retardation layers, with controlled central axis orientations and angles, to manipulate polarized light for enhanced luminance control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If a conventional viewing angle control system is used, then image visibility is controlled, but asymmetrical luminance control in tilted directions cannot be achieved

Engineering Contradiction:

Improveluminance in tilted directionsVSAvoidasymmetrical luminance control capability

Core Design Contradiction:

Illumination intensityVSAdaptability or versatility

Solution Approach 1:

The patent applies asymmetry by configuring the transmittance central axes of the first, second, and third light absorption anisotropic layers at different angles relative to the normal direction of the layers. Specifically, the angle between the transmittance central axis of the first layer and the normal direction differs from the angle between the transmittance central axis of the second layer and the normal direction, creating asymmetrical luminance distribution in tilted directions while maintaining high luminance in the front direction.

Inventive Principle:

Principle #4Asymmetry

2Illumination intensity

If multiple light absorption anisotropic layers are added to achieve asymmetrical luminance, then luminance control is improved, but device complexity increases

Engineering Contradiction:

Improveluminance control precisionVSAvoidnumber of layers

Core Design Contradiction:

Illumination intensityVSDevice complexity

Solution Approach 1:

The patent segments the light absorption function into three distinct light absorption anisotropic layers, each with specifically controlled transmittance central axis orientations. This segmentation allows independent optimization of luminance control in different directions, achieving asymmetrical luminance distribution while maintaining manageable device complexity through systematic layer configuration.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Each light absorption anisotropic layer is assigned a specific local quality in terms of its transmittance central axis orientation angle. The first layer has a different angle configuration compared to the second layer, allowing each layer to contribute differently to the overall luminance distribution, with the third layer completing the asymmetrical pattern. This local quality differentiation enables precise luminance control without requiring excessive layers.

Inventive Principle:

Principle #3Local quality

3Illumination intensity

If the transmittance central axes are oriented at different angles, then asymmetrical luminance is achieved, but manufacturing precision requirements increase

Engineering Contradiction:

Improveasymmetrical luminance distributionVSAvoidangle control precision

Core Design Contradiction:

Illumination intensityVSManufacturing precision

Solution Approach 1:

The patent employs parameter changes by specifying concrete angle ranges for the transmittance central axes of the light absorption anisotropic layers. The angle between the transmittance central axis of the first layer and the normal direction is controlled within a specific range, and the angle for the second layer is controlled within a different specific range. These parameter specifications provide clear manufacturing targets, balancing the achievement of asymmetrical luminance with practical manufacturing precision requirements.

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 optical laminate achieves the highest luminance in the front direction with asymmetrical luminance in tilted directions, reducing glare and enhancing visibility in vehicle displays.

Implementation Method 1

a first light absorption anisotropic layer; a second light absorption anisotropic layer; a third light absorption anisotropic layer

Methodology Applied

Scientific EffectLight absorption anisotropy: Absorption (EM radiation)

Implementation Method 2

an absorbing dichroic substance having an immobilized alignment

Methodology Applied

Scientific EffectDichroism: Dichroic Filter

Implementation Method 3

the first retardation layer has a function of changing a direction of linearly polarized light incident from a normal direction of the first retardation layer to a direction having an angle of 90°±10° with respect to the direction

Methodology Applied

Scientific EffectBirefringence: Birefringence

Data Source

PatentUS20250334729A1Optical laminate and image display apparatus

Publication Date: 2025.10.30 FUJIFILM CORP

AI summary

An optical laminate having the highest luminance in the vicinity of a front direction and having a luminance that is asymmetrical in a direction tilted from the front direction in a case where the optical laminate is applied to a light source, and an image display apparatus. The optical laminate includes a first light absorption anisotropic layer, a first retardation layer or a first liquid crystal cell, a second light absorption anisotropic layer, a second retardation layer or a second liquid crystal cell, and a third light absorption anisotropic layer in this order. Accordingly, various requirements are satisfied.