Reflector Array Layout for Mid-Air Images Without False Display

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Solution Overview

Problem

Existing reflective image-forming elements using dihedral corner reflectors and corner cube reflectors face issues with false image display and complex device structures.

Innovation Solution

An image-forming element with a base member and a reflector array featuring multiple dihedral corner reflector rows, where the angles between the reflecting surfaces and a virtual plane are carefully set to minimize false images, using a transparent resin base member and light-reflective metal surfaces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If dihedral corner reflectors are used for image formation, then the device structure is simplified, but false images are displayed at unintended locations

Engineering Contradiction:
Improvedevice structureVSAvoidfalse image display
Core Design Contradiction:
Device complexityVSObject-generated harmful factors

Solution Approach 1:

The patent applies local quality by varying the angle between adjacent reflector rows in different regions of the reflector array. Specifically, the angle between reflector rows changes from the center toward the edges, with each row having a unique angle optimized for its local position. This local variation ensures that reflected light from each row contributes to the intended image formation without creating false images at unintended locations, while maintaining a relatively simple overall device structure based on dihedral corner reflectors.

Inventive Principle:
Principle #3Local quality

2Object-generated harmful factors

If corner cube reflectors are used for image formation, then false image display is avoided, but the device structure becomes larger and more complex

Engineering Contradiction:
Improvefalse image displayVSAvoiddevice structure
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The patent applies segmentation by dividing the reflector array into multiple independent reflector rows, where each row consists of multiple dihedral corner reflectors arranged at specific angles. This segmentation allows each row to be optimized independently for its specific function in image formation, avoiding the need to use complete corner cube reflectors for all positions. The segmented structure achieves false image elimination through angular variation while maintaining a more compact and simpler overall device structure compared to traditional corner cube reflector arrangements.

Inventive Principle:
Principle #1Segmentation

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 provides an image-forming element with simple structures that effectively display images in mid-air without false images, utilizing a transparent resin base and reflective metal surfaces to enhance image clarity.

Implementation Method 1

the first reflecting surface is arranged to reflect light from the first surface side

Methodology Applied
Scientific EffectLight reflection: Reflection

Implementation Method 2

the second reflecting surface is arranged to be orthogonal to the first reflecting surface and arranged to reflect a reflected light from the first reflecting surface toward the first surface side

Methodology Applied
Scientific EffectLight reflection: Reflection

Data Source

PatentEP4365666B1Image-forming element and image display device
Publication Date: 2026.03.25 NICHIA CORP
  • EP4365666B1 patent drawingFigure 1
  • EP4365666B1 patent drawingFigure 2
  • EP4365666B1 patent drawingFigure 3

AI summary

An image-forming element according to one embodiment comprises a base material having a first surface, and a reflector array provided on the base material. The reflector array includes a plurality of reflector rows having a plurality of two-surface orthogonal reflectors provided along a first direction. The plurality of reflector rows are arranged in parallel with gaps therebetween in a second direction intersecting the first direction. The plurality of two-surface orthogonal reflectors each include a first reflective surface provided so as to reflect light from the first surface side, and a second reflective surface provided so as to be orthogonal to the first reflective surface and provided so as to reflect reflected light from the first reflective surface to the first surface side. The tilt of the second orthogonal reflectors is set such that an image is formed on the first surface side as referenced to the base material.