P-136 : A Study on the Dynamic Characteristics of Bend Cell for Practical Application of OCB mode LCD

Abstract

We have investigated on the dynamic LC characteristics of bend cells to achieve a high performance optical property and operational reliability in bend state of OCB (optically compensated bend) mode for practical application. Based on the different phase‐transformation features between initial bend transition and bend to splay relaxation, the dynamic LC response of OCB mode could be practically controlled up to a certain degree using specific dynamic driving scheme with consideration of dynamic response characteristics. Consequently, the evaluated optimum driving scheme was applied to proto‐type of 2.03″ LTPS QVGA‐OCB LCD and the obtaining results were evaluated within the framework of practical application for mobile display without deliberation of motion blur.

High-brightness relaxed-bend state in a pi cell stabilized by synchronized polymerization

“…In this paper, the nonpermanent RB state which was reported to have high brightness 9 is observed and stabilized by our proposed technique. This pi cell stabilized in the RB state has the attributes of high intensity operational range ͑an enhancement is obtained by a factor of 1.5 compared with the best case of the conventionally polymerized pi cell͒ and feasibility for full dynamic range optical compensation ͑no twist state occurs during the device operation͒.…”

“…The third category is to use intermittent pulse signals to prevent the recovery from the bend state to the twist state. 9 This method has been reported to maintain a relaxed-bend ͑RB͒ state, which has the highest phase retardation, or say the highest brightness, among the range of the bend states. However, there is still considerable tendency of the cell recovering from the bend state into the twist or splay states.…”

Study of Twisted Optically Compensated Bend Cell Using Patterned Alignment

“…3) To maintain the bend state at a low voltage (V < V cr ), a maintenance bias or pulse voltage (V > V cr ) is necessary. 4,5) The nonbias-bend (NBB) method has been proposed to eliminate the warm-up time and the maintenance bias. 6) However, owing to the high pretilt angle (>50 ), the optical retardation of the NBB cell is usually insufficient.…”