Holographic Display Optics for Ghost Image Suppression

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Solution Overview

Problem

Existing display devices in head-mounted displays suffer from degradation in display quality due to unwanted reflections and inefficiencies in light utilization, leading to ghost images and reduced image clarity.

Innovation Solution

A display device configuration comprising a display panel, first and second holographic optical elements, a polarizer, lens element, and retardation films is employed, where specific angles of incidence and polarization states are managed to ensure efficient light condensation and absorption, minimizing unwanted reflections and enhancing image clarity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional display device configuration is used, then device simplicity is maintained, but display quality degrades due to unwanted reflections and light utilization inefficiencies

Engineering Contradiction:

Improvedisplay qualityVSAvoidoptical system complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The optical system is segmented into multiple functional layers: first and second holographic optical elements for light redirection, multiple retardation films (first, second, and third) for polarization control, and a polarizer for final light filtering. Each segment performs a specific function to collectively eliminate unwanted reflections and improve light utilization efficiency.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Retardation films serve as intermediary elements between the holographic optical elements and the polarizer. These films mediate the polarization state of light passing through the system, ensuring that only desired light paths reach the user's eye while blocking unwanted reflections and ghost images.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Use of energy by moving object

If light utilization efficiency is improved through multiple optical elements, then display quality enhances, but device thickness increases

Engineering Contradiction:

Improvelight utilization efficiencyVSAvoiddevice thickness

Core Design Contradiction:

Use of energy by moving objectVSLength of stationary object

Solution Approach 1:

The optical elements are arranged in a nested configuration where the first and second retardation films are positioned between the holographic optical elements and the polarizer. This nested arrangement allows multiple functional layers to be compactly integrated without proportionally increasing device thickness, as each layer serves multiple purposes (polarization control, reflection suppression, and light guiding).

Inventive Principle:

Principle #7Nested doll (Nesting)

3Measurement precision

If polarization control is enhanced to suppress ghost images, then image clarity improves, but light loss increases

Engineering Contradiction:

Improveimage clarityVSAvoidlight loss

Core Design Contradiction:

Measurement precisionVSLoss of energy

Solution Approach 1:

The system utilizes parameter changes in the polarization state of light as it passes through different retardation films. The first, second, and third retardation films progressively modify the polarization parameters to eliminate ghost images while the holographic optical elements efficiently redirect light to maximize the amount of useful light reaching the user's eye.

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 configuration achieves improved light utilization efficiency, reduces device thickness, and suppresses ghost images, resulting in enhanced display quality and weight reduction.

Implementation Method 1

a first holographic optical element opposed to the display panel; a second holographic optical element opposed to the first holographic optical element

Methodology Applied

Scientific EffectHolographic optical element:

Implementation Method 2

a polarizer opposed to the second holographic optical element, transmitting first linearly polarized light, and absorbing second linearly polarized light orthogonal to the first linearly polarized light

Methodology Applied

Scientific EffectPolarization: Polarisation

Implementation Method 3

a lens element opposed to the polarizer and having a lens action of condensing first circularly polarized light of light transmitted through the second holographic optical element

Methodology Applied

Scientific EffectLens action: Lens

Implementation Method 4

a first retardation film located between the first holographic optical element and the second holographic optical element; a second retardation film located between the polarizer and the lens element; and a third retardation film located between the second holographic optical element and the polarizer

Methodology Applied

Scientific EffectRetardation: Birefringence

Data Source

PatentUS12386182B2Display device that can suppress degradation of display quality

Publication Date: 2025.08.12 MAGNOLIA WHITE CORP

AI summary

According to one embodiment, a display device includes a display panel, a first holographic optical element, a second holographic optical element, a polarizer transmitting first linearly polarized light and absorbing second linearly polarized light orthogonal to the first linearly polarized light, a lens element having a lens action of condensing first circularly polarized light of light transmitted through the second holographic optical element, a first retardation film located between the first holographic optical element and the second holographic optical element, a second retardation film located between the polarizer and the lens element, and a third retardation film located between the second holographic optical element and the polarizer.