Critical Field for a Hysteresis-Free BPLC Device

A low voltage and submillisecond-response polymer-stabilized blue phase liquid crystal

“…21 In addition, the hysteresis is about 6% because of the strong peak electric field near the IPS electrode edges. 25 A delicate balance between operating voltage, response time, and hysteresis has to be taken into consideration.…”

“…Above E c , hysteresis will gradually grow and response time becomes slower. 25,39 Therefore, the cell gap of a VFS cell plays an important role affecting the on-state voltage and hysteresis.…”

The optical threshold and saturation voltage of blue-phase liquid crystal display with uniform operating electric field

“…[1] In general, BPLCD needs a strong electric field to obtain large induced birefringence because of the small pitch double-twist structure of blue phase liquid crystal. [2] In conventional in-plane-switching BPLCD (IPS-BPLCD), the strong in-plane electric field generated by electrodes are mainly confined near the substrate, so the induced birefringence only appears in a thin LC layer close to substrate.…”

“…[4] The protrusion electrode is proposed to reduce the driven voltage, but the electric field intensity is nonuniform and the peak electric filed intensity is also high enough, so that the hysteresis effect is difficult to reduce, only the elliptical electrode has low electric filed intensity and shows good hysteresis effect. [1,[5][6][7][8][9][10][11] In BPLCD with protrusion electrodes, the operating voltage is also reduced to 10 V, but the hysteresis effect cannot be reduced because the peak electric field intensity is large enough near the break angle of the protrusion electrodes. [1] Recently, BPLCD with optimised wall-shaped electrodes was proposed, and no memory effect and hysteresis were obtained because of the curved wall-shaped electrode in the experimental cell.…”

“…[1,[5][6][7][8][9][10][11] In BPLCD with protrusion electrodes, the operating voltage is also reduced to 10 V, but the hysteresis effect cannot be reduced because the peak electric field intensity is large enough near the break angle of the protrusion electrodes. [1] Recently, BPLCD with optimised wall-shaped electrodes was proposed, and no memory effect and hysteresis were obtained because of the curved wall-shaped electrode in the experimental cell. [12] In vertical field switching (VFS) mode BPLCD, [13][14][15] the electric field between the two substrates is regarded as uniform, and the induced birefringence is perpendicular to the substrate, so the light must be set as oblique incidence to obtain the change of phase retardation, and the operating voltage is related to the oblique incidence angle.…”