十一、研究計畫中英文摘要：
請就本計畫要點作一概述，並依本計畫性質自訂關鍵詞。ASIA University Compurter Science Engineering
Title：The research of improving the characteristics of OCB mode liquid crystal by applying excimer laser technology
Principal Investigator： Chao-Nan Chen Sponsor：National Science Council
Keywords：Excimer laser technology; liquid crystal display, OCB mode liquid crystal, nucleation points, pretilt angle.
The purpose of this program is, by using excimer laser technology, to allocate PI (Poly-Imide) to the surfaces for producing different microstructures so to increase nucleation points of OCB (Optically Compensated Bend) mode liquid crystal and the control of pretilt angle, and thereby improve the convert issues of OCB mode liquid crystal.
OCB mode, having a wide viewing angle and high-speed response, etc., can solve the needs of the response time required for all the LCD(Liquid Crystal Display). However the main technical problem for the OCB mode is that the arrangement of liquid crystal molecules from splay to bend is not continuous, and the operation takes a long warm-up time; this problem can be solved by increasing the production of nucleation points to reduce the convert time, and improved by reducing the convert energy through controlling the pretilt angle.
Due to the Excimer laser technology processing advantages such as a simple, stable and high variability, which pattern design can be just changed by the mask, in recent years, it has been widely used in high-quality liquid crystal displays and the relevant process.
The current OCB mode liquid crystal display focuses on the increase of nucleation points production, and is mainly based on the Spacer- or Rubbing- oriented method to manufacture defects and produce nucleation points; however these methods are not easy to control generated nucleation point position, and the production amount of nucleation points by the random emergence is not much.The use of excimer laser technology combined with design of the laser mask will be able to precisely control the location and the number of nucleation points in the PI surface so to increase the number of OCB nucleation points and the speed of transform significantly, and reduce the convert time.The research of pretilt angle control at present mainly focuses on the mixture of alignment layers, but this method is not easy to control the production of pretilt angle. So we take advantage of excimer laser technology which is used to produce the PI surface of rough alignments by micro-processing, and it is expected that the sample of high pretilt angle can be produced, and the issues for OCB state transform can be solved.
The parameters to complete laser processes includes laser energy density, Shot Number, and different mask designs. By using the optimum parameters obtained by the control of nucleation point production and pretilt angle, the production of OCB mode liquid crystal cells and optical characteristics can be further analyzed to confirm the impact of the laser generated nucleation point and the pretilt angle on OCB mode transform, and solve the drawbacks of OCB mode transform to achieve the best optimization process of OCB mode liquid crystal sample.
