Integrated Light Sensor in Electroluminescent Device

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Solution Overview

Problem

Existing light-emitting devices with integrated sensors suffer from reduced light power emission and low efficiency due to the incorporation of photodiodes, which also obstruct the luminous flux and are costly to measure separately.

Innovation Solution

A light-emitting device design featuring semiconductor elements like microwires or nanowires with a partially reflective layer, insulating layers, and strategically placed photodiodes to measure radiation without obstructing the light emission, using III-V or II-VI compounds on semiconductor substrates like silicon or GaAs, and conductive tracks to enhance efficiency and integration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a separate light sensor is used to measure radiation emitted by the electroluminescent device, then measurement capability is achieved, but additional cost is incurred and the sensor must block part of the luminous flux

Engineering Contradiction:
Improveradiation measurement capabilityVSAvoidluminous flux obstruction
Core Design Contradiction:
Measurement precisionVSObject-generated harmful factors

Solution Approach 1:

The patent combines the light sensor and electroluminescent device into a single integrated structure where the sensor is positioned within the device body. This merging eliminates the need for separate external sensors that would block light, while maintaining measurement capability through internal photodiode elements that detect radiation without obstructing the luminous flux path.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The light sensor is nested within the electroluminescent device structure, with the photodiode sensor positioned inside the device housing. This nested configuration allows the sensor to measure radiation emitted by the device without being external to it, thereby avoiding luminous flux obstruction while maintaining measurement functionality.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Adaptability or versatility

If semiconductor wires are modified to form light sensors, then integration is achieved, but the wires no longer participate in light emission reducing maximum light power

Engineering Contradiction:
Improveintegration capabilityVSAvoidlight power emission
Core Design Contradiction:
Adaptability or versatilityVSPower

Solution Approach 1:

The patent segments the device into distinct functional zones: light-emitting semiconductor wires in one region and photodiode sensor elements in another region. This segmentation allows certain wires to be dedicated to light emission while other elements handle sensing, preventing the reduction in light power that would occur if all wires were modified for sensing purposes.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the device are assigned different functional properties: the semiconductor wires maintain their light-emitting properties in specific areas, while photodiode elements are positioned in regions optimized for radiation detection. This local differentiation ensures that light-emitting regions are not compromised by sensor integration.

Inventive Principle:
Principle #3Local quality

3Duration of action of moving object

If photodiodes are placed in the emission field for continuous measurement, then continuous measurement is achieved, but part of the luminous flux is blocked

Engineering Contradiction:
Improvecontinuous measurement capabilityVSAvoidluminous flux obstruction
Core Design Contradiction:
Duration of action of moving objectVSObject-generated harmful factors

Solution Approach 1:

The continuous measurement capability is achieved by merging the sensor into the device structure itself, allowing the photodiode to continuously monitor radiation emitted by the electroluminescent elements without being positioned in the external emission field. This integration eliminates luminous flux obstruction while maintaining continuous measurement functionality.

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 allows for continuous, efficient measurement of light emission without reducing the device's power output, improving sensor efficiency and integrating the sensor within the light-emitting device to prevent light obstruction, thus maintaining or enhancing the device's luminous performance.

Implementation Method 1

a light sensor, comprising at least one photodiode

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Implementation Method 2

an at least partially reflective layer covering the semiconductor regions

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 3

light-emitting devices based on semiconductor materials suitable for effecting the conversion of an electrical signal into electromagnetic radiation

Methodology Applied
Scientific EffectElectroluminescence: Electroluminescence

Data Source

PatentEP3347917B1Electroluminescent device with integrated light sensor
Publication Date: 2019.10.30 ALEDIA INC
  • EP3347917B1 patent drawingFigure 1~2
  • EP3347917B1 patent drawingFigure 3~4F
  • EP3347917B1 patent drawingFigure 5~7

AI summary

The invention relates to a light-emitting device (10) comprising: a substrate (14) at least partially doped with a first type of conductivity and comprising a face (18); light-emitting diodes (DEL) each comprising at least one three-dimensional semiconducting element (20) which is undoped or doped with the first type of conductivity and resting on the said face; and semiconducting regions (19) forming photodiodes (PH), at least partially doped with a second type of conductivity opposite to the first type of conductivity and extending in the substrate from the said face between at least some of the three-dimensional semiconducting elements, a portion (32) of the substrate of first type of conductivity extending up to the said face (18) at the level of each three-dimensional semiconducting element.