Optical System Thickness Reduction via Spacer Elimination

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Solution Overview

Problem

Existing optical systems for presenting synthetic images require an optical spacer to maintain focal distance, leading to increased thickness and potential tampering risks, as well as reduced image clarity and contrast due to light scattering and birefringence.

Innovation Solution

The system eliminates the need for an optical spacer by tailoring the focal length of focusing elements, allowing structured image icons to intersect the depth of focus without one, resulting in a thinner, more tamper-resistant, and higher contrast image presentation system.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of stationary object

If an optical spacer is used to maintain focal distance between focusing elements and image icons, then the focal distance is maintained, but the system thickness increases and tamper resistance decreases

Engineering Contradiction:
Improvesystem thicknessVSAvoidtamper resistance
Core Design Contradiction:
Length of stationary objectVSReliability

Solution Approach 1:

The patent removes the optical spacer component from the system entirely. By tailoring the focal length of the focusing elements to work without a spacer, the invention eliminates this component that caused increased thickness and potential tampering risks, directly resolving the technical contradiction between maintaining focal distance and reducing system vulnerability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention changes the focal length parameter of the focusing elements to be optimized for direct contact or near-contact with the image icons. This parameter adjustment allows the system to achieve proper focus without requiring the optical spacer, thereby reducing thickness and improving tamper resistance while maintaining optical performance.

Inventive Principle:
Principle #35Parameter changes

2Length of stationary object

If an optical spacer is used to maintain focal distance, then the focal distance is maintained, but image clarity and contrast decrease due to light scattering and birefringence

Engineering Contradiction:
Improvesystem thicknessVSAvoidimage clarity and contrast
Core Design Contradiction:
Length of stationary objectVSManufacturing precision

Solution Approach 1:

By removing the optical spacer from the system, the invention eliminates the source of light scattering and birefringence effects. This extraction of the problematic component directly improves image clarity and contrast while also reducing system thickness, simultaneously addressing both aspects of the technical contradiction.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention adjusts the focal length parameter of the focusing elements to compensate for the removal of the optical spacer. This parameter change enables the system to achieve sharp focus and high contrast images directly at the image icon plane without the degrading effects of light scattering and birefringence that would occur with a spacer.

Inventive Principle:
Principle #35Parameter changes

3Length of stationary object

If the focal length of focusing elements is tailored to eliminate the optical spacer, then system thickness is reduced and tamper resistance is improved, but the focal distance maintenance becomes more challenging

Engineering Contradiction:
Improvesystem thicknessVSAvoidfocal distance maintenance
Core Design Contradiction:
Length of stationary objectVSEase of manufacture

Solution Approach 1:

The invention precisely controls the focal length parameter of the focusing elements during manufacturing to match the specific geometry of the image icons. This parameter optimization ensures that the system achieves proper focus without a spacer, making the manufacturing process more precise but eliminating the need for complex spacer assembly and alignment procedures.

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

This approach reduces system thickness, enhances image clarity and contrast, and increases tamper resistance by eliminating the optical spacer, making the system more suitable for surface-applied security features and allowing for transfer without a carrier substrate, while maintaining sharp and detailed projected images.

Implementation Method 1

Focusing elements contemplated for use in the present invention include refractive, reflective (e.g., concave reflective, convex reflective), hybrid refractive/reflective, and diffractive focusing elements

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 2

Focusing elements contemplated for use in the present invention include refractive, reflective (e.g., concave reflective, convex reflective), hybrid refractive/reflective, and diffractive focusing elements

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP3970957A1Method of manufacturing a transferable optical system with a reduced thickness
Publication Date: 2022.03.23 VISUAL PHYSICS LLC
  • EP3970957A1 patent drawingFigure 1~2
  • EP3970957A1 patent drawingFigure 3~4
  • EP3970957A1 patent drawingFigure 5~7

AI summary

An optionally transferable optical system with a reduced thickness is provided. The inventive optical system is basically made up of a synthetic image presentation system in which one or more arrangements of structured image icons are substantially in contact with, but not completely embedded within, one or more arrangements of focusing elements. The focusing element and image icon arrangements cooperate to form at least one synthetic image. By way of the subject invention, the requirement for an optical spacer to provide the necessary focal distance between the focusing elements and their associated image icons(s) is removed. As a result, overall system thicknesses are reduced, suitability as a surface, applied authentication system is enabled, and tamper resistance is improved.