Multi-Focal Plane Display Using Transparent Emissive Layers

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Solution Overview

Problem

Portable computing devices like PDAs face challenges in providing an enlarged display area without compromising display brightness due to power constraints and the need for additional display layers, which lead to intrinsic attenuation of light and impractical backlighting luminance increases.

Innovation Solution

A method involving the addition of at least partially transparent emissive layers between display screens in distinct focal planes, utilizing a polarized transparent organic light-emitting diode (TOLED) and a wire grid polarizer to maintain uniform light intensity and prevent contrast degradation, allowing for multi-focal plane displays without additional powered illumination.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If additional transparent display screens are added to enlarge display area, then display area is increased, but light intensity is attenuated and brightness is reduced

Engineering Contradiction:
Improvedisplay areaVSAvoidbrightness
Core Design Contradiction:
Area of stationary objectVSIllumination intensity

Solution Approach 1:

The transparent display screen incorporates an emissive layer that generates its own light, making the display self-illuminating. This eliminates dependence on external backlighting and prevents light attenuation through multiple layers, as each layer contributes its own light output rather than merely transmitting light from another source.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The display employs a composite structure combining transparent substrates with emissive materials (such as OLED or TOLED layers). This composite construction allows the display to simultaneously achieve transparency for enlarged display area and self-emission for maintained brightness, resolving the contradiction between these two parameters.

Inventive Principle:
Principle #40Composite materials

2Illumination intensity

If backlighting luminance is increased to compensate for light attenuation, then brightness is maintained, but power consumption increases

Engineering Contradiction:
ImprovebrightnessVSAvoidpower consumption
Core Design Contradiction:
Illumination intensityVSUse of energy by moving object

Solution Approach 1:

The emissive layer serves dual functions: it provides the necessary illumination for display visibility and simultaneously acts as the display medium itself. This self-service approach eliminates the need for separate, high-power backlighting systems, as the emissive materials (OLED/TOLED) can be driven at lower power levels while still providing adequate brightness.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The invention transitions from a reflective/transmissive display model requiring strong backlighting to a self-emissive model where the display elements themselves generate light. This parameter change in the illumination mechanism allows for lower overall power consumption while maintaining brightness, as emissive materials can be efficiently controlled at the pixel level.

Inventive Principle:
Principle #35Parameter changes

3Area of stationary object

If multiple display layers are added to create multi-focal plane display, then display area and depth are enhanced, but device complexity increases

Engineering Contradiction:
Improvedisplay areaVSAvoiddisplay structure complexity
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The invention merges the functions of multiple display layers into a single integrated structure where transparent screens with emissive layers are stacked at different focal planes. This combining approach creates a multi-focal plane display that enhances display area and provides depth perception while managing complexity through functional integration rather than separate components.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The display extends into the third dimension by positioning transparent screens with emissive layers at different focal planes, creating a multi-focal plane structure. This dimensional extension increases display area and provides depth cues without requiring lateral expansion, and the layered emissive structure manages complexity by organizing display elements along the optical axis.

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

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 enables a practical multi-focal plane visual display unit with retained transflective display constructions, providing enhanced display area without sacrificing brightness, and allows for low-power illumination in high ambient light conditions.

Implementation Method 1

utilizing a polarized transparent organic light-emitting diode (TOLED)

Methodology Applied
Scientific EffectLight-emitting diode: Light Emitting Diode

Implementation Method 2

A method involving the addition of at least partially transparent emissive layers between display screens

Methodology Applied
Scientific EffectElectroluminescence: Electroluminescence

Implementation Method 3

utilizing a polarized transparent organic light-emitting diode (TOLED) and a wire grid polarizer to maintain uniform light intensity

Methodology Applied
Scientific EffectPolarisation: Polarisation

Implementation Method 4

The function of the fluorescent light tubes is to produce and direct incoherent light into the interior of the light guiding panel within which the light is typically bounded by the well known principle of 'total internal reflection'

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Implementation Method 5

Typical PDA transflective displays consist of a birefringent liquid with a chiral additive

Methodology Applied
Scientific EffectBirefringence: Birefringence

Implementation Method 6

The birefringence of the liquid crystal may be switched to zero by applying an electric field perpendicular to the alignment layers

Methodology Applied
Scientific EffectLiquid crystal: Liquid Crystals

Data Source

PatentEP3111424B1A display interposing a physical object within a three-dimensional volumetric space
Publication Date: 2020.12.30 APTIV TECHNOLOGIES LTD
  • EP3111424B1 patent drawingFigure 1~2
  • EP3111424B1 patent drawingFigure 3
  • EP3111424B1 patent drawingFigure 4~5

AI summary

A visual display unit creating a three-dimensional volumetric space. The display includes a first screen in a first focal plane, wherein the first screen displays a first image. The display includes a second screen in a second focal plane distinct from the first focal plane, wherein the second screen displays a second image, and wherein the second screen at least partially overlaps the first screen. The display includes a physical object located between the first screen and said second screen, wherein at least one of the first and second images is displayed in response to a placement of the physical object.