Flexible Electrophoretic Display utilizing LTPS-TFT Circuitry Transfer Technology (SUFTLA^TM)

Abstract

Aiming at electronic paper applications, we are pursuing flexible elctrophoretic displays by combining two key technologies:microencapsulated electrophoretic (MEP) and SUFTLA^TM, LTPS-TFT circuitry transfer technology. MEP possesses such ideal features as printed-material-like image quality and intrinsic flexibility. On the other hand, however, it requires active-matrix driving scheme because of its slow response and lack of threshold property. We chose LTPS, which has much higher electrical performances than a-Si, in order to achieve high-resolution display panels. Moreover we developed a novel process called SUFTLA^TM, which is a technology to transfer TFT circuitry from an original glass plate onto a film. Comparing with directly forming TFTs on a plastic, transferring method is superior in taking full advantages of LTPS-TFT's high performances. By integrating a film TFT substrate utilizing SUFTLA^TM with a MEP sheet provided by E-Ink Co. (E Ink Imaging Film^TM), we successfully developed a 7.1-in. QVGA (397ppi) flexible AM-EPD panel and confirmed its operation even while bent.