Display Device Light Blocking Layer for Biometric Sensing

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing display devices face challenges in achieving improved sensing performance for biometric information recognition, particularly in accurately detecting and processing external inputs such as fingerprints.

Innovation Solution

The display device incorporates an enhanced input sensing layer with a specific configuration of conductive and insulation layers, along with a color filter layer and a light blocking layer, to improve the detection of biometric information by reducing unwanted light reflection and enhancing sensitivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a conventional sensing layer configuration is used, then the device structure remains simple, but the sensing performance for biometric information recognition is insufficient

Engineering Contradiction:
Improvesensing performanceVSAvoidlayer configuration
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The sensing layer is divided into multiple distinct layers including a first sensing layer with first conductive layers and a second sensing layer with second conductive layers. Each layer performs specific sensing functions, allowing the system to achieve improved biometric recognition performance through specialized sub-components rather than a single undifferentiated structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the sensing structure are assigned different properties and functions. The first and second conductive layers are positioned at different locations with different orientations, creating local variations in electrical properties that enhance the detection of specific biometric features while maintaining overall structural coherence.

Inventive Principle:
Principle #3Local quality

2Measurement precision

If light blocking layers are added to reduce reflection, then sensing performance improves, but the device structure becomes more complex

Engineering Contradiction:
Improvedetection accuracyVSAvoidlayer structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The light blocking layers are integrated into the existing multi-layer sensing structure rather than being added as separate external components. The blocking layers are positioned between the sensing layers and the display elements, merging the light management function with the sensing function in a unified structure that reduces reflected light interference while maintaining detection accuracy.

Inventive Principle:
Principle #5Merging (Combining)

3Measurement precision

If multiple conductive layers are used to enhance sensitivity, then biometric recognition accuracy improves, but manufacturing complexity increases

Engineering Contradiction:
Improvebiometric recognition accuracyVSAvoidmanufacturing complexity
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The first and second conductive layers are pre-positioned and configured during the manufacturing process before final assembly. The layers are arranged in specific patterns and orientations during fabrication, allowing for optimized sensing performance to be built into the structure from the outset rather than requiring complex post-manufacturing adjustments or alignments.

Inventive Principle:
Principle #10Preliminary action

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 enhances the display device's ability to accurately recognize biometric information, such as fingerprints, by minimizing interference from reflected light and improving the overall sensitivity of the sensing mechanism.

Implementation Method 1

a light receiving sensor FX disposed between two corresponding pixels PX that are adjacent to each other in the second direction DR2

Methodology Applied
Scientific EffectLight detection: Photoelectric Effect

Implementation Method 2

a color filter layer CFL and a window WM disposed on the input sensing layer ISP

Methodology Applied
Scientific EffectLight absorption and blocking: Absorption (EM radiation)

Data Source

PatentEP4227914B1Display device
Publication Date: 2025.04.02 SAMSUNG DISPLAY CO LTD
  • EP4227914B1 patent drawingFigure 1
  • EP4227914B1 patent drawingFigure 2
  • EP4227914B1 patent drawingFigure 3~4

AI summary

A display device includes: a display panel to display an image; and a light blocking layer over the display panel. The display panel includes: a base layer; and an element layer over the base layer, the element layer including a light emitting element, a light receiving element, and an element defining film between the light emitting element and the light receiving element. The light blocking layer includes: a light blocking portion overlapping with the element defining film in a plan view, the light blocking portion having a first light blocking opening overlapping with the light emitting element, and a second light blocking opening overlapping with the light receiving element; and a protrusion protruding from the light blocking portion toward the element defining film.