Improvement of the Surface Anchoring Energy of the Photo-Alignment Layer in a Liquid Crystal Display using the Two-Band UV Exposure Method

Abstract

In this paper, we proposed the photo-alignment method with the strong surface anchoring energy by applying the two band UV exposure method on the photosensitive PI layer embedded with reactive mesogens (RMs) for achieving the fast response time properties of the in-plane switching (IPS) LC mode. We first enhanced the interconnection between a RM polymer and a photo-alignment layer through high band ultra-violet (UV) exposure on the long pass UV filter over 340 nm and then established the alignment of LCs through low band linear polarized UV exposure at 254 nm after eliminating the UV filter. As results, we measured the surface anchoring energy and response time of the proposed photo-alignment method and also confirmed that the optical response time was reduced by approximately 22.3 % compared to that of the IPS-LC cell of pure photo-alignment layer.