Two-Line Addressing Technique for SSFLC Displays

A new approach to speed up the addressing of Surface Stabilized Ferroelectric Liquid Crystal (SSFLC) displays by selecting two rows at a time is proposed. It combines the ideas from fast addressing modes of SSFLC with multiline selection of root-mean-square responding devices. The technique has been verified experimentally. switching process has the decisive role. The writing pulse is preceded by a long erase pulse. It ensures that the pixels are in a well-defined and repeatable state of the pixel prior to writing. The time gap between erasing and writing reduces the influence of the erase pulse and speeds up the switching. An additional compensation pulse, placed before the erase pulse, ensures the DC in the entire waveform is zero. The Control Window (CW) consists of four time-slots. These are used to obtain either a high amplitude, high rms signal across the pixel, or a low amplitude, low rms voltage during the CW. In the first situation the switching is held back and the pixel remains in the erased state since the writing pulse is then too weak to move the liquid crystal molecules sufficiently far towards the opposite state. This movement is dominated by the ferroelectric torque. The switching is concluded by the dielectric torque stemming from the ACfield generated by the cross-talk.