Holographic Optical Element Alignment Mark Integration

Solution Overview

Problem

Existing optical element manufacturing techniques require larger holographic materials due to alignment marks being outside the interference fringe formation region, leading to increased exposure device size.

Innovation Solution

An optical element with a holographic material layer forming diffraction grating and discontinuous interference fringes within the optically effective area, allowing alignment marks to be formed within the diffraction region, reducing the need for larger holographic materials and enabling precise alignment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If alignment marks are provided outside of the interference fringe formation region, then alignment can be performed, but the holographic material size must be larger than the optically effective area and the exposure device size increases

Engineering Contradiction:

Improvealignment precisionVSAvoidholographic material area

Core Design Contradiction:

Measurement precisionVSArea of stationary object

Solution Approach 1:

The patent merges the alignment mark function with the optically effective area by forming discontinuous interference fringes within the diffraction region. This integration eliminates the need for separate alignment mark areas, allowing alignment marks to be formed within the optically effective area where the holographic material diffracts incident light, thereby reducing the overall holographic material size while maintaining alignment capability.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent applies local quality by creating specific regions with discontinuous interference fringes within the optically effective area. These localized marking areas have different optical properties (discontinuous fringes) compared to the surrounding continuous fringe regions, enabling alignment functionality to be embedded within the diffraction region without affecting the overall optical performance.

Inventive Principle:

Principle #3Local quality

2Measurement precision

If alignment marks are provided outside of the interference fringe formation region, then alignment can be performed, but the exposure device size increases

Engineering Contradiction:

Improvealignment precisionVSAvoidexposure device length

Core Design Contradiction:

Measurement precisionVSLength of stationary object

Solution Approach 1:

The patent merges the alignment mark function with the optically effective area by forming discontinuous interference fringes within the diffraction region. This integration eliminates the need for separate alignment mark areas, allowing alignment marks to be formed within the optically effective area where the holographic material diffracts incident light, thereby reducing the overall holographic material size while maintaining alignment capability.

Inventive Principle:

Principle #5Merging (Combining)

3Area of stationary object

If discontinuous interference fringes are formed within the optically effective area, then alignment marks are formed within the diffraction region reducing holographic material size, but the interference fringes must be discontinuous which may affect diffraction uniformity

Engineering Contradiction:

Improveholographic material areaVSAvoidinterference fringe continuity

Core Design Contradiction:

Area of stationary objectVSStability of the object's composition

Solution Approach 1:

The patent applies local quality by creating specific regions with discontinuous interference fringes within the optically effective area. These localized marking areas have different optical properties (discontinuous fringes) compared to the surrounding continuous fringe regions, enabling alignment functionality to be embedded within the diffraction region without affecting the overall optical performance.

Inventive Principle:

Principle #3Local quality

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 allows for accurate alignment and reduces the size of the exposure device, as alignment marks are formed within the optically effective area, facilitating efficient light diffraction and minimizing the holographic material required.

Implementation Method 1

an optical element diffracting incident light, the optical element including a substrate having translucency, and a holographic material layer disposed so as to overlap the substrate, the holographic material layer being formed with a diffraction grating composed of interference fringes

Methodology Applied

Scientific EffectDiffraction: Diffraction

Implementation Method 2

the holographic material layer being formed with a diffraction grating composed of interference fringes

Methodology Applied

Scientific EffectInterference: Interference

Data Source

PatentUS11269192B2Optical element, having holographic material layer, display device, and method for manufacturing optical element

Publication Date: 2022.03.08 SEIKO EPSON CORP

AI summary

A deflection optical element, which diffracts incident light, includes a substrate having translucency, and a holographic material layer disposed so as to overlap the substrate, the holographic material layer being formed with a diffraction grating composed of interference fringes, wherein the holographic material layer is formed with an alignment mark where the interference fringes are discontinuous, and the alignment mark is located in an optically effective area where the holographic material layer diffracts the incident light.