P‐109: Stress‐Free Folding Hinge for Foldable OLED Display Device

The core technologies for the foldable display device are a flexible OLED panel, a flexible cover window and a folding hinge. Among them a hinge controls folding motion trajectory of an OLED panel. It is very important for an OLED panel not to apply any additional stress during folding motion. We developed the stress‐free folding (SFF) hinge with a virtual axis structure (VAS). Using SFF hinge we can achieved that the stress on OLED panel during folding is almost same as the free folding stress. As a result, there is no issue on an OLED panel in 200k folding reliability test with SFF hinge. Its torque reduction is less than 20% after 200k folding test.