Light Field Image Engine With DMD Mirror Scanning for Compact 3D Display

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Solution Overview

Problem

Current 3D display technologies face challenges such as low resolution, large physical size, high manufacturing costs, and the lack of suitable Spatial Light Modulator components for creating detailed wavefronts, leading to suboptimal 3D experiences with issues like vergence-accommodation conflict and limited angular resolution.

Innovation Solution

A Light Field Image Engine (LFIE) system utilizing a digital micromirror device (DMD) and a rotating mirror to project multiple images in various angular directions, synchronized with a light engine, enabling correct retinal focus cues and smooth transitions between views.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If volumetric display techniques are used to provide correct focus cues, then natural 3D perception is improved, but the device becomes large, expensive, and low resolution

Engineering Contradiction:
Improvefocus cues accuracyVSAvoidphysical size
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent creates a light field copy of the original scene by capturing light rays from multiple angles and reconstructing them in a controlled manner. Instead of using volumetric physical objects, the system captures and reproduces the light field properties (intensity, direction, position) to create virtual images that provide correct focus cues, thereby achieving natural 3D perception without the physical constraints of volumetric displays

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent transitions from controlling only spatial domain (conventional displays) to controlling both spatial and angular domains (light field displays). By adding angular dimension control through microlens arrays and multiple views, the system provides depth information and focus cues without requiring large physical volumes, effectively solving the contradiction between focus accuracy and device size

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

2Reliability

If holographic display is used to reconstruct light wavefronts, then correct retinal focus cues are provided, but suitable Spatial Light Modulator components are lacking

Engineering Contradiction:
Improveretinal focus cuesVSAvoidcomponent availability
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent introduces microlens arrays as an intermediary component between the display and the viewer's eye. These microlens arrays act as optical mediators that manipulate light rays to create multiple virtual images at different depths, providing correct retinal focus cues without requiring complex holographic spatial light modulators. The microlens arrays are commercially available and easier to manufacture, thus resolving the component availability issue

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent segments the light field into multiple discrete views by using microlens arrays to create separate optical paths for different viewing angles. Instead of attempting to reconstruct the entire continuous wavefront (which requires complex holographic SLMs), the system divides the light field into manageable angular segments that can be displayed using conventional display technologies combined with microlens optics, making the system more manufacturable

Inventive Principle:
Principle #1Segmentation

3Reliability

If super multi view techniques with 512 views are used to reduce view transitions, then 3D perception quality is improved, but the system complexity and manufacturing cost increase

Engineering Contradiction:
Improve3D perception qualityVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements dynamic view selection based on eye tracking technology. Instead of statically providing all 512 views simultaneously (which would require extremely high pixel densities and complex hardware), the system dynamically determines the viewer's eye position and adjusts the light field rendering to provide only the necessary views. This dynamic adaptation maintains high 3D perception quality while significantly reducing the required hardware complexity and manufacturing cost

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of view density from a fixed high value (512 views) to a dynamically adjusted value based on actual viewing conditions. By using eye tracking to monitor viewer position and adjusting the number of views rendered accordingly, the system maintains smooth transitions and high 3D quality when needed while reducing computational and hardware requirements during normal operation, thereby lowering overall system complexity and cost

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

The LFIE system provides high-resolution, compact, and cost-effective 3D displays with natural retinal focus cues, reducing eye strain and improving the 3D perception by accurately projecting images to different focal planes, allowing for shared experiences without headgear.

Implementation Method 1

outputting light from a light engine onto a digital micromirror device (DMD); operating the DMD as a pixelated spatial light modulator, to reflect at least some of the output light from the light engine as images to a rotating mirror

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 2

rotating the rotating mirror at a cycle rate to scan images represented by light reflected from the DMD through an angular viewing range

Methodology Applied
Scientific EffectRotation:

Data Source

PatentEP4030753B1Light field image engine method and apparatus for generating projected 3D light fields
Publication Date: 2026.02.25 INTERDIGITAL MADISON PATENT HLDG
  • EP4030753B1 patent drawingFigure 1A
  • EP4030753B1 patent drawingFigure 1B
  • EP4030753B1 patent drawingFigure 2A~2D

AI summary

Systems and methods are described for providing a three-dimensional display. In an example, a display device includes a light engine, a spatial light modulator, one or more directable mirrors, and a projection lens. Light from the light engine is modulated by the spatial light modulator, reflected by the directable mirror(s) toward the projection lens, and projected by the projection lens (e.g. onto a screen). The directable mirror(s) may include a rotatable mirror or a digital micromirror device. The spatial light modulator may be a digital micromirror device. The spatial light modulator and the directable mirror(s) are synchronized so as to generate different modulated light patterns for different positions of the directable mirror(s). The projection of different modulated light patterns in different directions may generate different views that are visible from different user perspectives.