Low-Power Displays With Dye-Doped Bistable Chiral-Tilted Homeotropic Nematic Liquid Crystals

Abstract

Energy-efficient display has been drawing much attention in recent years due to the prevailing of mobile devices as well as the rising environmental concerns. A chiral nematic system with appropriately configured pre-tilted angle and pitch length is capable of switching between the twist-like and homeotropic-like states with the merit of bistability. Introducing dichroic dyes into this system, we demonstrated a bistable scheme of liquid-crystal display without the need of polarizers. Index Terms-Liquid crystals (LCs), reflective displays. 1551-319X

Controlling the Pretilt Angles of Guest–Host Liquid Crystals via a Hydrophilic Polyimide Layer through Oxygen Plasma Treatment

“…When a high-frequency electric field was applied across the cell, the transmittance decreased. In contrast, the transmittance increased as a low-frequency electric field was applied. , These are two different behaviors involving applied frequencies that vary but similar electric field amplitudes, with the pretilt angle at 52.24°.…”

“…In contrast, the transmittance increased as a low-frequency electric field was applied. 37,38 These are two different behaviors involving applied frequencies that vary but similar electric field amplitudes, with the pretilt angle at 52.24°. The analyzed GHLC cell could be applied to GHLC-based smart windows that contain the two modes that are generally available in such windows.…”

Photo-switchable chiral liquid crystal with optical tristability enabled by a photoresponsive azo-chiral dopant

“…The contrast ratio of the dye-doped TCHN is primarily limited by the dichroic ratios of the dyes used and likely imperfect adiabatic following. However, this problem can be solved by simply adding a supplementary retarder based on our previous work [16]. Figure 5(b) delineates the reflective contrast ratios of the tristable device at various applied voltages V across an additional E7 cell as a variable phase retarder (see Ref.…”

“…Figure 5(b) delineates the reflective contrast ratios of the tristable device at various applied voltages V across an additional E7 cell as a variable phase retarder (see Ref. 16 for detailed information about the corresponding electro-optical measurement at λ = 632.8 nm). One can see from Fig.…”

“…The control or extent of light absorption can be realized by an applied electrical field to reorient the LC molecules and, in turn, the axial orientation of main absorption of the dye. White and Taylor suggested that a system of dye-doped, twisted-nematic LC device can absorb light polarized along all axes [15] Recently, Lee et al have devised a polarizer-free display based on a dye-doped bistable chiral-tilted homeotropic nematic (BHN) system [16]. They show that, by introducing dichroic dyes into a BHN host, a bistable display can be realized.…”