Study Of A Simplified Model Based On Hybriy Aligned Nematic LCD Mode Driven By Fringe-Field Switching (HAN-FFS)

In liquid crystal displays (LCDs), the improvement of image quality becomes more crucial to the extension of their market and competition with other types of displays.Recently, Seung Hee LEE have reported a new type of displays that is hybrid aligned nematic LCD driven by fringe-field switching (HAN-FFS),which shows a good viewing angle, high transmission and low driving.Voltage with a reduced number of manufacturing processes.HAN-FFS mode has attraction for improving image qualituy and showing a much wider viewing angle.The article sets up a simplified model based on HAN-FFS mode Seung Hee LEE proposed liquid crystal cell using a liquid crystal with positive dielectric anisotropy.Because ,in that display mode ,the threshold vertical component of electric field not produces voltage .The horizontal component play a main role.In order to resovle voltage problem .The model supposes:Firstly:the electric field of electrode in liquid crystal cell is even.Secondly:bend elastic constant ,twist elastic constant and splay are equal,namely, K₁₁ = K₂₂ = K₃₃=K.By using liquid crystal elastic theory to analyze the simplified model,we found the approximate threshold voltage expression of HAN-FFS mode.It relates to cell gap ,electrode width , elastic constant andε。To fully understand the switching principle when using the LC ,a simulation was performed using computer based on Jones matrix method for optical calculations.We obtain derector distributon and voltage-dependent transmittance curves.From the result ,we can see the simplified model have threshold voltage at bigger rubbing angle .This result is communicate with the HAN-FFS mode Seung Hee LEE proposed which has threshold voltage.As the rubbing angle becoming smaller,the threshold voltage will become lower and lower . It will disappear at the end.The HAN-FFS mode can resolve viewing angle problem very well.And it improves low transmittance ,response time,narrow viewing angle。We believe this mode will play a important role in LCDs field.