Under-Display Fingerprint Sensor Integration

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing electronic devices face challenges in increasing the display area while maintaining effective fingerprint sensing capabilities, as traditional methods require separate fingerprint sensing areas that reduce screen real estate.

Innovation Solution

The integration of a fingerprint sensor under a window in an electronic device, where the sensor is positioned on a part of the bottom surface of the window, allowing for simultaneous touch and fingerprint detection within the display area, enhancing sensitivity and eliminating the need for a dedicated fingerprint sensing region.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a separate fingerprint sensing area is constructed on the front surface, then fingerprint sensing capability is provided, but the display area is reduced

Engineering Contradiction:
Improvefingerprint sensing capabilityVSAvoiddisplay area
Core Design Contradiction:
Measurement precisionVSArea of stationary object

Solution Approach 1:

The patent combines the fingerprint sensing function with the display area by placing the fingerprint sensor beneath the display screen at a specific position. This merging allows the display area to serve dual purposes: displaying information and sensing fingerprints for authentication, thereby eliminating the need for a separate dedicated fingerprint sensing area while maintaining both functionalities

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent utilizes the vertical dimension by positioning the fingerprint sensor at a specific depth beneath the display surface (on the bottom surface of the window). This spatial arrangement in another dimension enables the fingerprint sensor to operate within the display area without reducing the visible display surface, resolving the contradiction between sensing capability and display area

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

2Area of stationary object

If the fingerprint sensor is placed farther from the finger contact area, then the display area is maximized, but the sensitivity of the fingerprint sensor decreases

Engineering Contradiction:
Improvedisplay areaVSAvoidfingerprint sensing sensitivity
Core Design Contradiction:
Area of stationary objectVSMeasurement precision

Solution Approach 1:

The patent applies local quality by positioning the fingerprint sensor at a specific location on the bottom surface of the window, directly beneath the finger contact area on the display surface. This localized placement ensures that the sensor is optimally positioned to detect fingerprints where users naturally place their fingers, maximizing sensitivity while maintaining full display area coverage

Inventive Principle:
Principle #3Local quality

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 improves fingerprint sensing sensitivity and allows for a larger display area by integrating the fingerprint sensor with the touch sensor, enabling seamless detection within the display area without compromising touch functionality.

Implementation Method 1

Each pixel includes a switch and a pixel electrode for forming a capacitance with a fingertip

Methodology Applied
Scientific EffectCapacitance: Capacitance

Implementation Method 2

a touch sensor disposed under the display area in the space and configured to output a signal in response to contact of a conductive object on the display area

Methodology Applied
Scientific EffectElectrostatic Induction: Electrostatic Induction

Data Source

PatentEP3279778B1Electronic device having fingerprint sensor
Publication Date: 2020.03.18 SAMSUNG ELECTRONICS CO LTD
  • EP3279778B1 patent drawingFigure 1
  • EP3279778B1 patent drawingFigure 2
  • EP3279778B1 patent drawingFigure 3

AI summary

An electronic device is provided, and may comprise a housing, a touch screen module, and a processor. The housing may include a first surface facing a first direction, a second surface facing a second direction opposite the first direction, and a side member including a side surface surrounding at least a part of a space between the first surface and the second surface. The touch screen module may be exposed through at least a part of the first surface. The processor may be located in the housing and electrically coupled to the touch screen module. In the electronic device, at least a part of the first surface may be a display area, and at least a part of the display area may be a fingerprint sensing area.