Research On Blue Phase Liquid Crystal Display

Polymer-stabilized blue phase liquid crystal(PS-BPLC)is emerging as the promising candidate for next-generation display because it can exhibit several revolutionary features: Its sub-millisecond response time is approximately ten times faster than the present nematic liquid crystal.It does not need alignment layer so that the fabrication process is simplified greatly.With an isotropic voltage-off state,it can achieve a wide and symmetric viewing angle.Its transmittance is insensitive to the cell gap as long as the gap cell exceeds the penetrative depth of the electric field,which can be used to fabricate the large-screen liquid crystal displays.However,two problems,high operating voltage and low transmittance,have restricted the development and implement of the blue phase liquid crystal display(BPLCD).In order to reduce the operating voltage and improve the transmittance,a BPCLD with the high dielectric constant protrusions is proposed,which are fixed on electrodes to replace the conventional protrusion electrodes.The BPLCD can be driven by a low operating voltage(~14V)and gain a high transmittance(~70%)through optimizing the dielectric constants and dimensions of the protrusions.The wider viewing angle can be obtained of the proposed BPLCD with a half-wave biaxial film to suppress the light leakages dramatically,which can satisfy the need of high-end LCDs.The effect of the protrusions alignment on the electrodes for the proposed BPLCD with the high dielectric constant materials is simulated and discussed.Further,a BPCLD with the high dielectric constant insulation layers is proposed,which are used to take the place of normal insulation layers.The BPLCD which is driven by double-side electrodes has a low operating voltage(~16V)and gains a high transmittance(~91%)through optimizing the dielectric constants and electrode dimensions.The wider viewing angle can be obtained of the proposed BPLCD with a half-wave biaxial film to suppress the light leakages dramatically,which can meet the need of high-end LCDs.Finally,a narrow viewing angle liquid crystal display(NVA-LCD)is proposed for BPLCD.Through using three uniaxial films,the BPLCD can exhibit an excellent NVA.Compared with the conventional narrow viewing angle mode,the proposed device does not have the complex electrode structure or a number of compensation films.Moreover,the compensation films have advantage in price than the privacy films produced by 3M company while maintain the excellent narrow viewing angle.