Biometric Sensor Embedded in Display via Waveguide

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Solution Overview

Problem

Conventional electronic devices with fingerprint recognition sensors require separate space on the surface, which is not desirable due to the trend of slim bezels in mobile devices.

Innovation Solution

Incorporating a biometric sensor within the display of an electronic device, utilizing a waveguide to propagate light or sound waves for fingerprint recognition, allowing the sensor to be integrated into the display area without additional surface space.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If a fingerprint recognition sensor is placed separately on the device surface, then the sensor can effectively recognize fingerprints, but it requires additional surface space that increases bezel size

Engineering Contradiction:
Improvesurface spaceVSAvoidfingerprint recognition functionality
Core Design Contradiction:
Area of stationary objectVSEase of operation

Solution Approach 1:

The patent integrates the fingerprint sensor with the display structure by merging the sensor layer with the display's touch panel or protective glass layer. The sensor is positioned between the display layers, allowing it to share the same surface area without requiring additional bezel space. This combining approach enables the fingerprint sensor to function effectively while maintaining a compact device design with minimized bezels.

Inventive Principle:
Principle #5Merging (Combining)

2Device complexity

If the biometric sensor is integrated within the display, then the device can achieve thinner bezels and more compact design, but the sensor must share space with display pixels

Engineering Contradiction:
Improveintegration structureVSAvoidsensor area
Core Design Contradiction:
Device complexityVSArea of stationary object

Solution Approach 1:

The patent resolves the space conflict by transitioning from a two-dimensional surface layout to a three-dimensional layered structure. The fingerprint sensor is positioned in the Z-dimension (thickness direction) between display layers, while the display pixels occupy the X-Y plane. This dimensional separation allows both the sensor and display to coexist without competing for surface area, enabling full display coverage with integrated biometric functionality.

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

Solution Approach 2:

The patent divides the display structure into multiple functional layers, with the fingerprint sensor occupying a specific layer or region between the protective glass and the active display elements. This segmentation allows independent optimization of each layer - the display layers for visual output and the sensor layer for biometric detection - while maintaining their spatial relationship within the integrated structure.

Inventive Principle:
Principle #1Segmentation

3Ease of operation

If a waveguide is added to transmit light to the biometric sensor, then the sensor can function within the display, but the structural complexity of the display increases

Engineering Contradiction:
Improvelight transmission for sensorVSAvoiddisplay structure
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent makes the display structure multi-functional by enabling it to serve both visual display and biometric sensing purposes. The same display layers and optical paths that transmit light to the display elements also transmit light to the fingerprint sensor. The waveguide structure is designed to fulfill dual roles: displaying visual content while simultaneously guiding light to the integrated sensor, thereby reducing overall device complexity despite the added functionality.

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

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 integration enables fingerprint sensing within the display, minimizing the need for extra space and allowing for thinner device designs while maintaining effective biometric functionality.

Implementation Method 1

a waveguide perpendicular to the biometric sensor and extending from the biometric sensor to the second portion

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Implementation Method 2

the biometric sensor being configured to sense a user's fingerprint

Methodology Applied
Scientific EffectLight reflection: Reflection

Data Source

PatentEP3523712B1Electronic device including biometric sensor
Publication Date: 2020.09.30 SAMSUNG ELECTRONICS CO LTD
  • EP3523712B1 patent drawingFigure 1
  • EP3523712B1 patent drawingFigure 2a
  • EP3523712B1 patent drawingFigure 2b

AI summary

According to an embodiment of the present disclosure, an electronic device may comprise a housing forming a first portion of an outer surface of the electronic device and a display received in the housing and forming a second portion of the outer surface. The display may include a biometric sensor formed between a first pixel and a second pixel and a waveguide substantially perpendicular to the biometric sensor and extending from the biometric sensor to the second portion. In an electronic device according to an embodiment of the present disclosure, light or ultrasonic waves may be put to use in sensing the user's biometric information (e.g., fingerprint information) using a biometric sensor positioned in a portion of the display, presenting better performance.