3D Display Light Source Spectral Shaping for Cross-Talk Reduction

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Solution Overview

Problem

Current 3D image display systems, such as 6P laser projectors, face issues with image cross-talk due to overlapping spectral bands of light sources, leading to reduced separation between spectral bands within the same color range, which affects the quality of the 3D image.

Innovation Solution

The implementation of light sources with emitters having narrow spectral distributions and short tails, where each emitter's spectral distribution is carefully positioned and spaced to minimize overlap and enhance separation between spectral bands, reducing cross-talk and speckle effects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional light sources with broad spectral distributions are used, then the light source can provide sufficient brightness and coverage, but spectral bands overlap causing image cross-talk between left and right eye views

Engineering Contradiction:
Improveimage qualityVSAvoidcross-talk between spectral bands
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent divides each color range (red, green, blue) into multiple discrete spectral bands by using separate emitters for each band. For example, the red color range is divided into first red spectral band and second red spectral band with distinct emitters. This segmentation prevents overlap between spectral bands used for left and right eye images, eliminating cross-talk while maintaining sufficient brightness through the combination of multiple narrow bands.

Inventive Principle:
Principle #1Segmentation

2Adaptability or versatility

If spectral bands are spaced closer together to improve color coverage, then the light source can achieve better color rendering, but cross-talk between left and right eye images increases

Engineering Contradiction:
Improvecolor coverageVSAvoidimage cross-talk
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The patent assigns different local spectral characteristics to different emitters within the same color range. Each emitter is optimized with a specific narrow spectral distribution tailored to its function. For instance, the first red emitter has a spectral distribution optimized for left eye red coverage while the second red emitter has a different spectral distribution for right eye red coverage. This local optimization allows precise control over spectral separation to prevent cross-talk while maintaining overall color coverage.

Inventive Principle:
Principle #3Local quality

3Object-affected harmful factors

If narrow spectral distributions are used to reduce cross-talk, then spectral band separation improves, but the light source may have reduced brightness and coverage

Engineering Contradiction:
Improvecross-talk reductionVSAvoidbrightness
Core Design Contradiction:
Object-affected harmful factorsVSIllumination intensity

Solution Approach 1:

The patent combines multiple narrow spectral bands within each color range to achieve sufficient overall brightness and coverage. For example, within the red color range, both the first red spectral band and second red spectral band contribute to the total red light output. By merging these multiple narrow bands, the system maintains high brightness and complete color coverage while each individual narrow band remains spectrally isolated to prevent cross-talk between left and right eye images.

Inventive Principle:
Principle #5Merging (Combining)

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 effectively reduces cross-talk between spectral bands, improving the separation and quality of 3D images by using narrow band emitters to create distinct spectral bands within color ranges, thereby enhancing the overall performance of 3D display systems.

Implementation Method 1

The first emitter emits light having a first spectral distribution within a first color (e.g., red) range

Methodology Applied
Scientific EffectLight emission: Light

Data Source

PatentEP3869261B1Spectral shaping for 3D imaging
Publication Date: 2024.02.14 DOLBY LABORATORIES LICENSING CORP
  • EP3869261B1 patent drawingFigure 1
  • EP3869261B1 patent drawingFigure 2
  • EP3869261B1 patent drawingFigure 3

AI summary

A novel light source for a 3D display system includes a plurality of left eye light emitters and a plurality of right eye light emitters. The left eye emitters include a broad spectral distribution emitter and an overlapping narrow spectral distribution emitter in each of the blue, green, and red color bands. Similarly, the right eye emitters include a broad spectral distribution emitter and an overlapping narrow spectral distribution emitter in each of the blue, green, and red color bands. The combined spectral distributions of each of the broad and narrow emitters provide a primary light for each color and for each eye that has a desirable spectral shape, including wide bandwidth and short tail(s). The invention thus minimizes cross-talk and speckling in left- and right-eye images of 3D display systems.