Rollable Display Pad Glass Segmentation for Stress Reduction
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Solution Overview
Problem
Rollable display devices face damage and stress issues due to repeated winding and unwinding, which can lead to damage of flexible films and printed circuit boards, and excessive stress on the display panel during winding.
Innovation Solution
A display device design featuring a display panel with a first back cover, pad glass, flexible films, and side lines that minimize stress transmission by using pads on the pad glass with increased rigidity, allowing the display panel to maintain a flat pad area and reduce tension during winding and unwinding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the display panel is wound around the roller, then the display device can be rolled up for portability, but excessive stress is applied to the display panel and flexible films causing damage
Solution Approach 1:
The pad area is segmented from the main display panel structure by using a separate pad glass substrate. This segmentation allows the pad glass to remain flat and rigid while the display panel can be wound, preventing stress concentration at the pad area during rolling operations.
Solution Approach 2:
The pad glass acts as an intermediary component between the flexible display panel and the rigid back cover. It provides a stable mounting surface for pads and flexible films while allowing the display panel to be wound without transmitting excessive stress to these components.
2Reliability
If flexible films are bonded directly to the display panel, then electrical connection is achieved, but repeated winding and unwinding causes damage to the flexible films
Solution Approach 1:
The flexible films are segmented from the display panel by bonding them to the pad glass instead. This separation allows the flexible films to be repaired or replaced independently without damaging the display panel, extending their service life.
Solution Approach 2:
The pad glass provides a rigid, stable foundation for the flexible films before winding occurs. This pre-established stable base cushions the flexible films from stress during winding and unwinding operations, preventing premature failure.
3Strength
If the pad area is made rigid to reduce stress, then stress transmission is minimized, but the display panel cannot be wound
Solution Approach 1:
The pad area is segmented into a separate rigid pad glass component that remains stationary while the display panel is wound. This segmentation resolves the contradiction by allowing the pad area to be rigid for stress resistance while the display panel maintains its flexibility for rolling.
Solution Approach 2:
The pad glass is positioned in a different spatial dimension (on the back cover rather than on the display panel itself), allowing it to maintain rigidity without interfering with the winding of the display panel. This dimensional separation enables both rigidity and rollability.
Data Source
AI summary
According to an aspect of the present disclosure, a display device includes a display panel, a first back cover supporting the display panel on a rear surface of the display panel, a roller around which the display panel and the first back cover are wound, a pad glass disposed on the rear surface of the first back cover and including a plurality of pads disposed thereon, a plurality of flexible films bonded to the pad glass, and a plurality of side lines electrically connecting the plurality of pads of the pad glass and the display panel. Accordingly, the plurality of pads is separately formed from the display panel so that any stress which may be transmitted to the plurality of pads and the plurality of flexible films when the display device is wound or unwound can be minimized.