Stacked Display Panel Pixels for Under-Display Biometric Sensing

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Solution Overview

Problem

Existing display devices face challenges in implementing biometric recognition sensors that maintain high sensitivity while ensuring display quality, whether the sensor is embedded under the display panel or manufactured as a separate module, due to performance degradation and design limitations.

Innovation Solution

A display panel design incorporating first, second, and third light emitting diodes emitting different wavelength spectra, each overlapped by corresponding organic photoelectric conversion diodes that selectively absorb and convert light into electrical signals, with the diodes and photoelectric conversion diodes arranged in parallel and sharing a common electrode, allowing for high-sensitivity biometric sensing without compromising display quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the sensor is embedded under the display panel, then the design integration is improved, but the recognition performance degrades due to light absorption by various films and parts

Engineering Contradiction:
Improvedesign integrationVSAvoidrecognition performance
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent transitions from a planar arrangement to a three-dimensional stacked configuration, placing the photoelectric conversion diode directly on the light emitting diode in the thickness direction. This vertical stacking eliminates the light path through multiple films and parts, resolving the contradiction between integrated design and recognition performance.

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

Solution Approach 2:

The photoelectric conversion diode is nested within the display panel structure by positioning it on the light emitting diode, creating a compact integrated unit. This nesting approach allows the sensor to be embedded while maintaining optimal light detection capability.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Reliability

If the sensor is manufactured as a separate module, then the recognition performance is maintained, but the design flexibility and usability are limited

Engineering Contradiction:
Improverecognition performanceVSAvoiddesign flexibility
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent merges the display function (light emitting diode) and sensing function (photoelectric conversion diode) into a single integrated pixel structure. This combination provides both design flexibility and maintained recognition performance, eliminating the need for separate modules.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The integrated pixel structure serves dual purposes: displaying visual information through the light emitting diode and detecting light for biometric recognition through the photoelectric conversion diode. This multi-functionality resolves the contradiction between performance maintenance and design flexibility.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Measurement precision

If the photoelectric conversion diode area is increased, then the sensitivity is improved, but the display aperture ratio decreases

Engineering Contradiction:
Improvesensor sensitivityVSAvoiddisplay aperture ratio
Core Design Contradiction:
Measurement precisionVSArea of stationary object

Solution Approach 1:

By stacking the photoelectric conversion diode on the light emitting diode in the thickness direction rather than expanding it laterally, the patent increases sensor sensitivity without reducing the display aperture ratio. The vertical arrangement allows both diodes to occupy the same planar footprint while maintaining optimal light detection area.

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

The solution enables high-sensitivity biometric recognition while maintaining display quality by optimizing the arrangement and absorption properties of light emitting diodes and photoelectric conversion diodes, enhancing both performance and usability.

Implementation Method 1

an organic photoelectric conversion diode overlapping the first light emitting diode along a thickness direction of the substrate and configured to selectively absorb light of the second and third wavelength spectra and convert the light of the second and third wavelength spectra into an electrical signal

Methodology Applied
Scientific EffectPhotoelectric conversion: Photoelectric Effect

Implementation Method 2

first, second, and third light emitting diodes on the substrate and configured to emit light of first, second, and third wavelength spectra belonging to a visible light wavelength spectrum, respectively

Methodology Applied
Scientific EffectLight emission: Light Emitting Diode

Data Source

PatentEP4440285B1Display panel and electronic device
Publication Date: 2025.11.19 SAMSUNG DISPLAY CO LTD
  • EP4440285B1 patent drawingFigure 1
  • EP4440285B1 patent drawingFigure 2
  • EP4440285B1 patent drawingFigure 3

AI summary

Disclosed are a display panel and an electronic device. The display panel may include a substrate, first, second, and third light emitting diodes on the substrate and configured to emit light of first, second, and third wavelength spectra in a visible light wavelength spectrum, respectively, and first, second, third organic photoelectric conversion diodes overlapping the first, second, and third light emitting diode along a thickness direction of the substrate, respectively, may be provided. Each of first, second, third organic photoelectric conversion diodes may be configured to selectively absorb a portion of the visible light wavelength spectrum and convert the absorbed light into an electrical signal.