Under-Display Micro-LED Sensor Region for ToF Transparency

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Solution Overview

Problem

Conventional displays limit the transparency required for optical sensors like ToF sensors, which are often located under the display, as they need to pass through the display, leading to reduced display quality in terms of brightness and resolution.

Innovation Solution

An electronic device design featuring a first display region with higher transmissivity for infrared light, using micro LEDs, and a second region with lower transmissivity, utilizing different display technologies to optimize light guidance and sensor performance, with the ToF sensor positioned behind the high-transmissivity region to enhance infrared light reception.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If optical sensors are located under the display, then the display can occupy the complete front side of the device, but the sensor performance is impaired due to limited display transparency

Engineering Contradiction:
Improvedisplay areaVSAvoidsensor measurement
Core Design Contradiction:
Area of stationary objectVSMeasurement precision

Solution Approach 1:

The display device implements different display technologies in different regions: a first display region with higher infrared transmissivity (using micro-LEDs) where the ToF sensor is located, and a second display region with lower transmissivity (using OLEDs) for normal display content. This local differentiation allows the sensor area to have optimized optical properties without compromising the overall display quality.

Inventive Principle:
Principle #3Local quality

2Measurement precision

If display transparency is increased for sensor performance, then sensor measurement improves, but display quality (brightness and resolution) is sacrificed

Engineering Contradiction:
Improvesensor measurementVSAvoiddisplay brightness
Core Design Contradiction:
Measurement precisionVSIllumination intensity

Solution Approach 1:

The display device implements different display technologies in different regions: a first display region with higher infrared transmissivity (using micro-LEDs) where the ToF sensor is located, and a second display region with lower transmissivity (using OLEDs) for normal display content. This local differentiation allows the sensor area to have optimized optical properties without compromising the overall display quality.

Inventive Principle:
Principle #3Local quality

3Measurement precision

If a single display technology is used throughout, then device complexity is reduced, but it is impossible to optimize both sensor transmissivity and display quality simultaneously

Engineering Contradiction:
Improvesensor measurementVSAvoiddisplay structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The display surface is divided into two distinct regions: a first display region using micro-LED technology for sensor area with higher infrared transmissivity, and a second display region using OLED technology for normal display content. This segmentation allows each region to be optimized for its specific function while working together as a unified display system.

Inventive Principle:
Principle #1Segmentation

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 significantly reduces impairment of the ToF sensor by the display, allowing a higher fraction of infrared light to reach the sensor while maintaining display quality, reducing power consumption for emitters, and enabling improved sensor performance.

Implementation Method 1

a first display region using a first display technology and exhibiting a first transmissivity for electromagnetic radiation... The first display region comprises at least one light-emitting element configured to emit the infrared light for illuminating the scene

Methodology Applied
Scientific EffectLight Emitting Diode: Light Emitting Diode

Data Source

PatentEP4002813B1Sensor positioned behind a micro-led area within an OLED display
Publication Date: 2024.10.09 INFINEON TECHNOLOGIES AG
  • EP4002813B1 patent drawingFigure 1~2
  • EP4002813B1 patent drawingFigure 3

AI summary

An electronic device (100) is provided. The electronic device (100) includes a display device (110) configured to display an optical image on a front side of the display device (110). Further, the electronic device (100) includes at least one sensor (120) configured to measure electromagnetic radiation received from a scene in front of the front side of the display device (110). The display device (110) includes a first display region (111) using a first display technology and exhibiting a first transmissivity for the electromagnetic radiation. The display device (110) further includes a second display region using a second display technology (112) and exhibiting a second transmissivity for the electromagnetic radiation. The first transmissivity is higher than the second transmissivity. The at least one sensor (120) is arranged on a back side of the display device (110) and faces the first display region (111).