Fingerprint Sensor Mounting on Foldable Display Metal Layer

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Solution Overview

Problem

Foldable display devices face issues with deformation and reduced fingerprint sensor sensitivity due to pressure applied in the folding region, leading to potential appearance degradation and sensitivity loss over repeated use.

Innovation Solution

Incorporating a metal layer and buffer members in the folding region, with a light blocking pattern and adhesive members, to distribute pressure and maintain sensor integrity, while allowing for flexible bending and reduced indentation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a fingerprint sensor is integrated in the folding region of a foldable display device, then the device can provide a larger screen and integrated functionality, but deformation and sensitivity loss occur due to repeated pressure during folding and unfolding

Engineering Contradiction:
Improveintegrated fingerprint sensor functionalityVSAvoidfingerprint sensor sensitivity
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The metal layer is divided into multiple portions (first metal portion in the first non-folding region, second metal portion in the second non-folding region, and third metal portion in the folding region). This segmentation allows each portion to be optimized for its specific location, with the third metal portion specifically designed to support the fingerprint sensor while the other portions provide structural support in non-folding regions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies different structural characteristics to different regions: the third metal portion is positioned closer to the display panel in the folding region to provide localized support for the fingerprint sensor, while the first and second metal portions are positioned farther away in non-folding regions. This local differentiation ensures the fingerprint sensor receives adequate support without compromising the overall flexibility of the folding region.

Inventive Principle:
Principle #3Local quality

2Adaptability or versatility

If buffer members are separated in the folding region to allow bending, then flexibility is improved, but structural support and pressure distribution are reduced

Engineering Contradiction:
Improvefolding flexibilityVSAvoidstructural support
Core Design Contradiction:
Adaptability or versatilityVSStrength

Solution Approach 1:

The patent combines multiple functions into the metal layer structure. The metal layer serves both as a structural support element and as a platform for mounting the fingerprint sensor. By integrating these functions into a single continuous structure that spans across the folding region, the patent achieves both flexibility and structural support without requiring separate buffer members in the folding region.

Inventive Principle:
Principle #5Merging (Combining)

3Ease of manufacture

If the fingerprint sensor is attached directly to the display panel in the folding region, then sensor integration is simplified, but deformation under pressure degrades appearance and performance

Engineering Contradiction:
Improvesensor attachment simplicityVSAvoiddisplay panel deformation
Core Design Contradiction:
Ease of manufactureVSShape

Solution Approach 1:

The third metal portion acts as an intermediary element between the display panel and the fingerprint sensor. It is disposed closer to the display panel than other metal portions, providing a stable mounting surface for the fingerprint sensor while being positioned to minimize interference with the folding action. This intermediary structure prevents direct attachment to the flexible display panel, thereby reducing deformation under pressure.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3761151B1Display device
Publication Date: 2023.04.26 SAMSUNG DISPLAY CO LTD
  • EP3761151B1 patent drawingFigure 1
  • EP3761151B1 patent drawingFigure 2
  • EP3761151B1 patent drawingFigure 3

AI summary

A display device includes a display panel disposed in a first non-folding region, a second non-folding region, and a folding region located between the first and second non-folding regions. The display device further includes first and second buffer members disposed on one surface of the display panel in the first and second non-folding regions, respectively, and a metal layer disposed in the first non-folding region, the second non-folding region, and the folding region on one surface of the first buffer member and one surface of the second buffer member. The display device further includes a fingerprint sensor disposed on the metal layer. The first and second buffer members are separated with the folding region therebetween. The metal layer includes first, second, and third metal portions located in the first non-folding region, the second non-folding region, and the folding region, respectively. The fingerprint sensor is attached to the third metal portion.