Flexible Input Sensor Layout for Rollable Display Reliability

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Solution Overview

Problem

Existing flexible display devices face challenges in maintaining rolling characteristics and reliability due to stress applied during rolling.

Innovation Solution

The display device incorporates a design with alternating areas of inorganic and organic insulating layers, featuring openings in certain areas to relieve stress, and includes a sensing electrode on the encapsulation layer to enhance input sensing capabilities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a continuous inorganic insulating layer is used in the input sensor, then the sensing performance and structural integrity are maintained, but stress concentration occurs during rolling causing poor rolling characteristics and reduced reliability

Engineering Contradiction:

Improverolling characteristicsVSAvoidstress concentration

Core Design Contradiction:

ReliabilityVSStress or pressure

Solution Approach 1:

The continuous inorganic insulating layer is divided into separate inorganic insulating layers spaced apart by openings. This segmentation allows the layer to flex during rolling without stress concentration, improving rolling characteristics while maintaining sensing functionality through the distributed sensing electrodes.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The inorganic insulating layer is designed with openings creating a porous structure. This porous configuration reduces stress during rolling by providing flexibility and stress relief paths, while the inorganic material maintains its protective and insulating functions in the sensing areas.

Inventive Principle:

Principle #31Porous materials

2Reliability

If openings are created in the inorganic insulating layer to relieve stress, then rolling characteristics improve, but the sensing area and input sensing capability are reduced

Engineering Contradiction:

Improverolling characteristicsVSAvoidsensing area

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

The inorganic insulating layer is selectively disposed in first areas while openings are provided in second areas, creating local variations in structure. The sensing electrodes are positioned to overlap with the inorganic insulating layer in the first areas, ensuring sensing capability is maintained where needed while stress relief is provided in the second areas.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The pattern of first and second areas is extended in the first direction to create a repeating structure. This dimensional extension allows the sensing function to be maintained across the entire sensor area through the distributed arrangement of sensing electrodes and inorganic insulating layers, compensating for the reduced local sensing area.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Data Source

PatentUS12535920B2Display device

Publication Date: 2026.01.27 SAMSUNG DISPLAY CO LTD

AI summary

A display device includes a display panel and an input sensor disposed on the display panel. The input sensor includes a plurality of first areas repeatedly arranged in a first direction, a plurality of second areas repeatedly arranged in the first direction, an inorganic insulating layer disposed in the first areas, an organic insulating layer disposed in the first areas and the second areas, and a sensing electrode disposed on the organic insulating layer. The first areas are alternately arranged in the first direction with the second areas, and the input sensor includes openings in the second areas that are formed by removing portions of the inorganic insulating layer from the second areas.