Autostereoscopic Display Light Guide Funnels Reduce Crosstalk

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Solution Overview

Problem

Autostereoscopic 3D displays using emissive and reflective technologies face challenges with light efficiency and crosstalk due to the diffuse emission of light, which is not effectively addressed by solutions designed for 2D displays, leading to reduced contrast and increased crosstalk when using lenticular lenses.

Innovation Solution

The implementation of a light guiding arrangement with tapered funnels over display pixels, combined with an autostereoscopic lens arrangement, to control the angular spread of light and reduce crosstalk, specifically optimizing the aperture ratio and collimation of light to improve performance in 3D autostereoscopic displays.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If emissive displays (OLED) are used to improve light efficiency and eliminate polarizers, then light emission efficiency is improved, but diffuse emission causes light to be recycled inside organic layers reducing light output and increasing crosstalk in 3D displays

Engineering Contradiction:
Improvelight emission efficiencyVSAvoidlight output
Core Design Contradiction:
Use of energy by moving objectVSLoss of energy

Solution Approach 1:

The display is divided into multiple sub-pixels (red, green, blue) arranged in a specific pattern, with each sub-pixel emitting light independently. This segmentation allows precise control of light emission from each color channel, improving overall light efficiency while managing the diffuse emission characteristic of OLEDs.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the display have different optical properties. The patent uses view-dependent rendering where the content and optical characteristics vary based on the viewer's position. This allows optimization of light emission and reduction of crosstalk in different spatial zones, addressing the diffuse emission issue locally rather than uniformly across the entire display.

Inventive Principle:
Principle #3Local quality

2Adaptability or versatility

If lenticular lenses are used in autostereoscopic displays to direct light to different views, then 3D imaging capability is improved, but light from one lenticular lens is reflected to neighboring lenses reducing contrast and increasing crosstalk

Engineering Contradiction:
Improve3D imaging capabilityVSAvoidcrosstalk
Core Design Contradiction:
Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

The patent employs asymmetric optical designs in the lenticular lens array and corresponding pixel arrangements. The lens shapes, sizes, and positions are asymmetrically configured to direct light from specific pixel groups to specific viewing zones. This asymmetry prevents symmetric reflection patterns that would cause crosstalk between adjacent lenses, while maintaining the autostereoscopic 3D imaging capability.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The patent introduces intermediate optical elements and structures between the OLED display and the lenticular lenses. These intermediates include specific pixel arrangements, optical films, and lens designs that act as mediators to control light paths, reduce reflections, and minimize crosstalk while preserving the 3D imaging function.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of manufacture

If LCD displays are used to generate images, then image display capability is achieved, but polarizers are required and light efficiency is reduced compared to emissive displays

Engineering Contradiction:
Improveimage display capabilityVSAvoidlight efficiency
Core Design Contradiction:
Ease of manufactureVSUse of energy by moving object

Solution Approach 1:

The patent extracts and eliminates the polarizer components from the display structure by transitioning from LCD to emissive display technology. This removal of unnecessary optical layers simplifies the manufacturing process, improves light efficiency by eliminating light absorption in polarizers, and enables the use of OLED pixels that emit light directly without requiring polarization filtering.

Inventive Principle:
Principle #2Taking out (Extraction)

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 solution enhances light extraction and reduces crosstalk, improving the overall performance and efficiency of autostereoscopic displays by directing light in a manner that minimizes waveguiding and maximizes emission perpendicular to the display surface, thereby enhancing image quality and viewer experience.

Implementation Method 1

the light guide columns comprise a side wall which tapers outwardly to define a funnel shape with the pixel or pixels at the smaller base of the funnel

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Implementation Method 2

an array of elongate lenticular elements can be provided extending parallel to one another and overlying the display pixel array, and the display pixels are observed through these lenticular elements

Methodology Applied
Scientific EffectRefraction: Refraction

Data Source

PatentEP2724543B1Autostereoscopic display device
Publication Date: 2015.10.07 KONINKLIJKE PHILIPS NV
  • EP2724543B1 patent drawingFigure 1
  • EP2724543B1 patent drawingFigure 2
  • EP2724543B1 patent drawingFigure 3~4

AI summary

An autostereoscopic display device comprises a display arrangement such as an emissive display arrangement or an reflective dispplay arrangement, with an array of spaced pixels. A light guiding arrangement has an array of light guide columns, with one column over each display pixel or over a group (such as a column) of pixels. The light guide columns comprise aside wall which tapers outwardly to define a funnel shape with the pixel at the smaller base of the funnel. The funnel provides collimation to reduce cross talk in the display, which is particularly problematic for 3D autostereoscopic displays.