Integrated Electronic Photonic Backplane for Display Panels

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Solution Overview

Problem

Conventional display assemblies face issues with low photon efficiency and bulky designs due to random light scattering by backlight units, leading to inefficient light directionality and high crosstalk between pixels, which complicates fabrication and increases costs.

Innovation Solution

A composite backplane architecture integrating an electronics layer, a photonic integrated circuit (PIC) layer, and an active light modulation (ALM) interface layer on a substrate, which directs and controls light from a light source to an active medium layer, reducing gaps between layers and eliminating the need for post-fabrication alignment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a conventional backlight unit with cover glass is used, then the display assembly is easier to manufacture, but the distance between the backlight unit and LCD panel increases resulting in bulky designs and reduced light efficiency

Engineering Contradiction:

Improveease of manufactureVSAvoiddisplay assembly volume

Core Design Contradiction:

Ease of manufactureVSVolume of moving object

Solution Approach 1:

The patent merges the backlight unit and LCD panel into a single integrated display panel structure, eliminating the need for separate cover glass layers and reducing the distance between light source and display medium. This integration directly reduces the overall volume while maintaining ease of manufacture through unified fabrication processes.

Inventive Principle:

Principle #5Merging (Combining)

2Ease of manufacture

If a conventional backlight unit with random light scattering is used, then the manufacturing process is simpler, but the directionality of light becomes uncontrollable resulting in low photon efficiency

Engineering Contradiction:

Improveease of manufactureVSAvoidphoton efficiency

Core Design Contradiction:

Ease of manufactureVSLoss of energy

Solution Approach 1:

The patent implements local quality control by incorporating a photonic integrated circuit layer with waveguide structures that selectively direct light along specific pathways to individual pixel locations. This enables precise control of light directionality and improves photon efficiency by ensuring light reaches only the intended pixels rather than scattering randomly.

Inventive Principle:

Principle #3Local quality

3Loss of energy

If a PIC-based backlight unit is used to control emission cone, then photon efficiency is improved, but post-fabrication alignment at high precision is required which is costly and time-consuming

Engineering Contradiction:

Improvephoton efficiencyVSAvoidease of manufacture

Core Design Contradiction:

Loss of energyVSEase of manufacture

Solution Approach 1:

The patent applies preliminary action by pre-integrating the photonic integrated circuit layer with the LCD panel layer during the fabrication process itself, rather than requiring post-fabrication alignment. The waveguide structures and light sources are positioned and connected in advance through coordinated lithography processes, eliminating the need for costly and time-consuming alignment steps while maintaining high photon efficiency.

Inventive Principle:

Principle #10Preliminary action

4Ease of manufacture

If cover glass is placed over the LCD panel and backlight unit, then the display assembly is easier to assemble, but the distance between layers increases resulting in bulky designs and increased crosstalk

Engineering Contradiction:

Improveease of manufactureVSAvoidoptical crosstalk

Core Design Contradiction:

Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent merges multiple layers including the backlight unit, photonic integrated circuit, and LCD panel into a single integrated structure without requiring separate cover glass. This eliminates the air gaps and distance between layers that cause optical crosstalk, while the integrated fabrication process maintains ease of manufacture through unified processing steps.

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

The solution enhances light efficiency, reduces optical crosstalk, and achieves a higher fill factor, resulting in a compact, high-pixel-density display panel that supports various light sources and can be fabricated using standard lithographic processes.

Implementation Method 1

a photonics integrated circuit (IC) layer disposed on the electronics layer that causes light from the light source to propagate in a first direction

Methodology Applied

Scientific EffectLight propagation direction control: Waveguide (optics)

Implementation Method 2

an active medium layer disposed on the ALM interface layer comprising sets of pixels including sets of an active media

Methodology Applied

Scientific EffectLight modulation: Liquid Crystals

Data Source

PatentUS11727891B2Integrated electronic and photonic backplane architecture for display panels

Publication Date: 2023.08.15 META PLATFORMS TECHNOLOGIES LLC

AI summary

In various embodiments, an apparatus comprises a composite backplane that modulates light from a light source, where the composite backplane comprises an electronics layer disposed on a substrate, a photonics integrated circuit (IC) layer disposed on the electronics layer that causes light from the light source to propagate in a first direction, and an active light modulation (ALM) interface layer disposed on the photonics IC layer controls an ALM interface layer in order to control the light propagating in the first direction.