Premium
P‐153: High Performance Photo‐aligned Surface of Vertical Alignment Liquid Crystal Displays for Mass Production
Author(s) -
Tseng Man-Chun,
Chiu Hon-Wah,
Tang Shu-Tuen,
Yeung Fion Sze-Yan,
Kwok Hoi-Sing
Publication year - 2020
Publication title -
sid symposium digest of technical papers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.351
H-Index - 44
eISSN - 2168-0159
pISSN - 0097-966X
DOI - 10.1002/sdtp.14296
Subject(s) - liquid crystal display , polyimide , materials science , rubbing , irradiation , optoelectronics , yield (engineering) , liquid crystal , liquid crystal on silicon , optics , layer (electronics) , viewing angle , computer science , composite material , physics , nuclear physics
Photoalignment technology has been proven useful in the patterned alignment display industry. For large area display, most of the available in‐plane switching (IPS) mode TVs or panels use photoalignment technology. Not only it allows free pattern alignment direction to the liquid crystal compared to the conventional rubbed polyimide, but also it provides high yield and stability. However, the cost of the photoalignment technology could be very high. The materials often require polarized deep UV irradiation with a finite dosage to generate pretilt angles. Due to the improper control of rubbing on the alignment layer, the low yield rate problem still exists in the passive LCD world, especially for vertical photoalignment LCDs. It would be ineffective to improve the yield rate problem with this technology. Furthermore, the required materials are not common in the market. In view of the situation, a Vertical Alignment (VA) surface by non‐polarized LED light irradiation with a large wavelength is proposed and demonstrated in this paper. The cost of the LED exposure equipment is relatively more affordable. In a series of factory pilot runs on the proposed alignment characteristics, it shows comparable result to conventional polyimides in terms of performance. It achieves a stable and uniform pretilt angle, with high anchoring energy and fast response time. To conclude, the proposed robust alignment layer could benefit the industry with a better performance at low cost.