Research On Reflective Blue Phase Liquid Crystal Display

Liquid crystal display(LCD)because of its lightweight,high quality,easy to large and other advantages,occupies a dominant position in the current display field.Response time is the main issue hinders the development of LCD technology.Compared with nematic liquid crystal,blue phase liquid crystal(BPLC)has the advantage of no orientation layer,sub-millisecond ultrafast response speed,making it one of the hotspots in the field of LCD.But the high operation voltage and hysteresis effects still hinders its widespread applications.Therefore,in this paper,the reflective structure is used to achieve low voltage,high reflectance and fast response reflective BPLCD.The electro-optical properties of the transmissive and reflective BPLCD are compared by simulation,and the operation voltage of the reflective BPLCD reaches 28.5V when it achieves the peak reflectance,which is 43%lower than that of the transmissive mode.By increasing the electrode height of the device can further reduce its operation voltage,which voltage can be reduced to 7.2V for the reflective BPLCD with electrode height of 3?m.The use of more sharp bump electrodes can increase the reflectance of reflective BPLCD,the reflective BPLCD with 3?m Rev-Ellipse shape electrodes reaches the maximum reflectance,which increases by 44%compared with conventional IPS reflective BPLCD,which lays the foundation of the reflective silicon-based devices.On this basis,the electro-optical properties of the reflective BPLCD with concave electrodes and double-side electrodes are studied by simulation.The concave electrodes can improve the reflectance,and the double-side electrodes can effectively reduce the operation voltage compared with the traditional IPS reflective BPLCD.Finally,the reflective BPLCD with double-side concave electrodes is proposed.The reflective BPLCD with double-side concave electrodes reaches the maximum reflectance when the operation voltage is 20V,the reflectance is increased by 25%and the operation voltage is reduced by about 30%compared with traditional IPS reflective BPLCD.The polymer stabilized blue phase liquid crystals(PS-BPLC)with different content of chiral agent is prepared.The effect of chiral agent on the PS-BPLC is studied.The phase transition temperature from the isotropic state to the blue phase state increases with the increase of chiral agent content.A transmissive and reflective IPS structure BPLCD are fabricated.The operation voltage of the reflective device is 65V,which is 28%lower than that of the transmissive mode.Compared with the fitting results,it is verified that the double optical path difference of the reflective mode can reduce the operation voltage of reflective BPLCD.The rise time is 0.6ms and the fall time is 1.8ms,meeting the requirements of field sequence display.