Compressive Light Field Projection Using Dual DMDs

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Solution Overview

Problem

Traditional light field projection techniques face limitations such as scalability issues, low frame rates, dimness, limited views, and depth in creating large, high-resolution 3D scenes without the need for 3D glasses.

Innovation Solution

A compressive light field projection system utilizing a pair of digital micromirror devices (DMDs) that interact to generate a light field, projected onto an angle-expanding screen with a Fresnel lens for straightening views and increasing field of view, employing compression techniques like binary non-negative matrix factorization to reduce the number of frames needed for image recreation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If traditional light field projection techniques are used, then 3D scenes can be displayed without glasses, but the frame rate is low and the image is dim

Engineering Contradiction:
Improveframe rateVSAvoidbrightness
Core Design Contradiction:
ProductivityVSIllumination intensity

Solution Approach 1:

The patent divides the light field projection into multiple discrete views that are sequentially displayed. Each view is projected for a brief period, and the human visual system integrates these sequential images into a continuous 3D perception. This segmentation allows the system to achieve high frame rates by projecting multiple views rapidly without requiring all views to be simultaneously visible, thereby maintaining brightness while improving productivity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system employs periodic projection of multiple light field views in rapid succession. Each view is projected for a short duration followed by the next view in sequence, creating a time-multiplexed display. This periodic action enables high frame rates by cycling through multiple views within a single frame period, while the persistence of vision maintains perceived brightness and continuity of the 3D image.

Inventive Principle:
Principle #19Periodic action

2Area of stationary object

If traditional light field projection techniques are used, then 3D scenes can be displayed without glasses, but the field of view and display size are limited

Engineering Contradiction:
Improvedisplay sizeVSAvoidfield of view
Core Design Contradiction:
Area of stationary objectVSAdaptability or versatility

Solution Approach 1:

The patent extends the light field projection into the temporal dimension by sequentially displaying multiple views over time. This time-multiplexed approach allows the system to project a large number of views that would be impossible to display simultaneously, effectively adding a temporal dimension to the spatial display. This enables both large display sizes and extensive fields of view without requiring all views to occupy physical space at the same time.

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

Solution Approach 2:

The patent segments the light field into multiple discrete angular views that are projected sequentially. Each view corresponds to a specific viewing angle, and by rapidly cycling through many such segmented views, the system achieves a wide effective field of view. This segmentation also allows the display to scale to large physical sizes while maintaining view quality across the extended area.

Inventive Principle:
Principle #1Segmentation

3Productivity

If compression techniques are used to reduce frames, then the number of frames needed is reduced, but image quality may be compromised

Engineering Contradiction:
Improveframe rateVSAvoidimage quality
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies compressive light field techniques that transform the light field representation into a compressed domain, reducing the number of views that need to be explicitly projected. By changing the parameter space from full-resolution multiple views to a compressed representation, the system achieves high frame rates while reconstructing high-quality images through optimized projection patterns and view synthesis algorithms.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses view synthesis to generate additional views from a reduced set of projected views. Instead of projecting every possible view at full resolution, the system projects a compressed set of representative views and synthesizes the remaining views through computational methods. This copying approach maintains image quality while significantly reducing the frame rate requirement.

Inventive Principle:
Principle #26Copying

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 system achieves faster, brighter, and deeper light fields with more views, capable of producing high-definition imagery over large areas, allowing for immersive 3D experiences without the need for glasses.

Implementation Method 1

an angle-expanding screen with a Fresnel lens for straightening views and increasing field of view

Methodology Applied
Scientific EffectFresnel lens: Fresnel Lens

Implementation Method 2

A compressive light field projection system utilizing a pair of digital micromirror devices (DMDs) that interact to generate a light field

Methodology Applied
Scientific EffectLight reflection: Reflection

Data Source

PatentEP3734971B1High speed binary compressive light field projection system
Publication Date: 2024.02.21 DISNEY ENTERPRISES INC
  • EP3734971B1 patent drawingFigure 1
  • EP3734971B1 patent drawingFigure 2A
  • EP3734971B1 patent drawingFigure 2BA~2BB

AI summary

Implementations of a compressive light field projection system are disclosed herein. In one embodiment, the compressive light field projection system utilizes a pair of light modulators, such as digital micromirror devices (DMDs), that interact to produce a light field. The light field is then projected via a projection lens onto a screen, which may be an angle expanding projection screen that includes a Fresnel lens for straightening the views of the light field and either a double lenticular array of Keplerian lens pairs or a single lenticular, for increasing the field of view. In addition, compression techniques are disclosed for generating patterns to place on the pair of light modulators so as to reduce the number of frames needed to recreate a light field.