Color Production Structure with Uneven Elements for Wide-Angle Viewing

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Color production structures that utilize thin film interference or multilayer film interference exhibit significant changes in hue and brightness when the observation angle changes, limiting their application due to directional dependence of intensified light wavelengths.

Innovation Solution

A color production structure with an uneven structure layer and a conforming optical layer, where the uneven elements have specific dimensions and a gradual height increase from the edge to the center, scattering reflected light in various directions to maintain color visibility across a wide range of angles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If a color production structure utilizes thin film interference or multilayer film interference, then a specific wavelength range of light is intensified by interference, but the hue and brightness change significantly when the observation angle changes

Engineering Contradiction:
Improveintensity of reflected lightVSAvoidvisibility across observation angles
Core Design Contradiction:
Illumination intensityVSAdaptability or versatility

Solution Approach 1:

The invention divides the surface into multiple uneven elements (convex or concave portions) with specific dimensional characteristics. Each uneven element acts as an independent light scattering unit, collectively distributing reflected light across wide angular ranges while maintaining interference-based color intensity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The uneven elements are designed with specific local dimensional properties (longitudinal width 40-50 μm, lateral width 40-50 μm, height ratio 0.1-1.0) that optimize light scattering in specific directions. This local structural quality enables controlled light distribution while preserving interference effects.

Inventive Principle:
Principle #3Local quality

2Manufacturing precision

If the optical path difference is optimized for a specific wavelength range, then light in that wavelength range is intensified by interference, but the color changes when the incidence angle changes

Engineering Contradiction:
Improveoptical path difference controlVSAvoidcolor consistency across angles
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The invention transitions from controlling only the optical path difference (one-dimensional parameter) to incorporating three-dimensional uneven structures with specific dimensional ratios. This adds spatial dimensionality to the interference control, enabling angle-independent color production while maintaining manufacturing precision for the optical path difference.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Illumination intensity

If the light emerges in the specular reflection direction, then the interference effect is maximized, but the color is only visible in a specific direction

Engineering Contradiction:
Improvebrightness of reflected lightVSAvoidobservation angle range
Core Design Contradiction:
Illumination intensityVSEase of operation

Solution Approach 1:

The uneven elements are designed with asymmetric dimensional characteristics (longitudinal width different from lateral width, specific height ratios) that create non-uniform light scattering patterns. This asymmetry distributes light across multiple directions rather than concentrating it in a single specular direction, expanding observation angle range while maintaining brightness.

Inventive Principle:
Principle #4Asymmetry

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 solution effectively suppresses color changes with observation angle, ensuring a specific color is visible across a broad range of angles by scattering reflected light from the optical layer, enhancing the structural color's visibility and design versatility.

Implementation Method 1

Color production structures are known that produce color by utilizing light interference such as thin film interference and multilayer film interference

Methodology Applied
Scientific EffectLight interference: Interference

Implementation Method 2

the optical layer has a surface shaped to conform to the uneven structure of the structure layer, which results in reflected light in a specific wavelength range that has been intensified by interference being scattered and emerging in various directions

Methodology Applied
Scientific EffectLight scattering: Scattering

Data Source

PatentEP3862798B1Coloring structure
Publication Date: 2024.01.24 TOPPAN HOLDINGS INC
  • EP3862798B1 patent drawingFigure 1~2
  • EP3862798B1 patent drawingFigure 3
  • EP3862798B1 patent drawingFigure 4~5

AI summary

A color production structure includes an uneven structure layer and a multilayer film layer. The uneven structure layer has an uneven structure on a surface thereof, the uneven structure including a plurality of uneven elements. The multilayer film layer is a laminated film on the uneven structure and has a surface shaped to conform to the uneven structure, the multilayer film layer configured such that reflected light enhanced by interference emerges from the multilayer film layer. Each of the uneven elements has a longitudinal width and a lateral width in plan view along a thickness direction of the uneven structure layer, each of the longitudinal width and lateral width of the respective uneven elements having a value within a range from 10 µm to 100 µm inclusive. Each of the uneven elements has a dimension in the thickness direction of the uneven structure layer, the dimension of each uneven element continuously increasing from the peripheral edge to the center thereof in the plan view. A ratio of a maximum value of the dimension of each of the uneven elements to the lateral width thereof is set to be within a range from 0.1 to 1.0 inclusive.