Transparent Optical Coupler Array With Wavelength-Separated Light Paths

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Solution Overview

Problem

Existing optocoupler arrays face challenges in separating control light for actuation from sensing light for imaging or sensing, leading to interference and poor image quality due to the backplane blocking the view.

Innovation Solution

Utilizing orthogonal wavelengths for control and sensing light, with materials transparent to sensing light and absorbing control light, and employing indium tin oxide (ITO) electrodes and dielectric layers to separate the light paths, ensuring the backplane is transparent to sensing light while isolating control light.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If the backplane is made opaque to block control light, then control light isolation is improved, but sensing light transmission is blocked causing poor image quality

Engineering Contradiction:
Improvecontrol light interferenceVSAvoidsensing light transmission
Core Design Contradiction:
Object-affected harmful factorsVSIllumination intensity

Solution Approach 1:

The patent applies wavelength-dependent material properties to achieve selective transparency. The backplane is designed to be opaque at control light wavelengths (e.g., blue/violet) while remaining transparent at sensing light wavelengths (e.g., green), resolving the contradiction through parameter changes in optical properties

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

Different regions of the backplane are designed with different optical properties for different wavelength ranges. The backplane has local quality variations that block control light in specific wavelength bands while allowing sensing light to pass through, enabling simultaneous isolation and transmission

Inventive Principle:
Principle #3Local quality

2Illumination intensity

If the backplane is made transparent for sensing light, then image quality is improved, but control light isolation is reduced causing interference

Engineering Contradiction:
Improvesensing light transmissionVSAvoidcontrol light interference
Core Design Contradiction:
Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

The patent uses wavelength-dependent optical parameters to achieve selective transparency. By designing materials with different absorption characteristics at different wavelengths, the backplane can be transparent to sensing light while blocking control light, resolving the contradiction through parameter changes

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces intermediary layers with specific optical properties that mediate between control light and sensing light. These intermediary layers act as wavelength-selective filters that allow sensing light to pass while blocking control light, enabling simultaneous transmission and isolation

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If single wavelength light is used for both control and sensing, then system simplicity is improved, but light path separation is insufficient causing interference

Engineering Contradiction:
Improvelight path separationVSAvoidlight interference
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

The patent segments the optical spectrum into different wavelength bands for control and sensing functions. By using multiple wavelengths (e.g., blue/violet for control, green for sensing) instead of a single wavelength, the system achieves better light path separation while maintaining reasonable system complexity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent adds the wavelength dimension to the optical system to achieve light path separation. Instead of separating light paths in spatial dimensions only, the system uses wavelength as an additional dimension for separation, allowing simultaneous control and sensing operations without interference

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

Achieves high on/off ratios and improved image quality by effectively separating control and sensing light paths, allowing flexible positioning and enhanced imaging capabilities.

Implementation Method 1

materials transparent to sensing light and absorbing control light

Methodology Applied
Scientific EffectLight absorption: Absorption (EM radiation)

Implementation Method 2

a region of photosensitive material that, when exposed to light, generates a voltage that causes the switch to activate

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Implementation Method 3

employing indium tin oxide (ITO) electrodes and dielectric layers to separate the light paths

Methodology Applied
Scientific EffectLight reflection: Reflection

Data Source

PatentEP3401725B1Transparent optical coupler active matrix array
Publication Date: 2026.01.07 PALO ALTO RESEARCH CENTER INC
  • EP3401725B1 patent drawingFigure 1
  • EP3401725B1 patent drawingFigure 2~3
  • EP3401725B1 patent drawingFigure 4~5

AI summary

A backplane has an array of output terminals arranged on an output surface of the backplane, and an array of solid state optical switches, each optical switch corresponding to one of the output terminals, wherein the solid state optical switches are responsive to light (93) of a control wavelength and are transparent to light (103) of a sensing wavelength, wherein the backplane is of a material transparent to light (103) of the sensing wavelength different from the control wavelength. An optical system (90) includes a backplane having an array of optocouplers, a projector (92) to generate light (93) of a control wavelength to which the optocouplers are responsive, optics (94) to direct the control light (93) onto the array of optocouplers on the backplane, and an imaging system responsive to light (103) of a sensing wavelength, wherein the backplane is at least partially transparent to light (103) of the sensing wavelength.