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A new fabrication technique and mixed monomers for a polymer-sustained-alignment liquid-crystal (PSA-LC) cell were proposed in this study. The proposed process for formation of the PSA layer is exposing visible light for polymerization instead of exposing ultraviolet (UV) light. The backlight consisted of light emitting diode (LED) for the LC display (LCD) was used as the source of the visible light, and the mixed monomers were 2,7-dimethacryloyl-oxy-phenanthrene (2,7-DMAPhen) and 4,4'-dimethacryloyl-oxy-benzil (4,4'-DMABzl). Since the monomer 4,4'-DMABzl could generate radicals by a hydrogen abstraction reaction under exposure of the visible light, the PSA layer was formed under the LED-backlight exposure through an intermediary of a polarizer. The fabricated PSA-LC cell showed equal level of voltage holding ratio, residual direct current voltage, and difference in pretilt angle before and after application of an alternate current voltage to the PSA-LC cell fabricated by the UV light exposure. Therefore, we expect that future PSA-LCD would be fabricated without exposure of the UV light. [ABSTRACT FROM AUTHOR]

A new fabrication method and its monomer for a polymer-sustained-alignment liquid-crystal (PSA-LC) cell was proposed in this study. The proposed process for formation of a polymer layer is a method to expose visible light for polymerisation of the monomers. As the visible light, a LED-backlight of a LC display (LCD) was used through the intermediary of a polariser. Therefore, the polymer layer was formed by the exposure of the LED-backlight after construction of the LCD. The proposed monomer is 4,4ʹ-dimethacryloyl-oxy-benzil, which can generate a radical by a hydrogen abstraction reaction for an initiation of the polymerisation under exposure of the visible light. The fabricated PSA-LC cell with the proposed method showed high voltage holding ratio, low residual direct current voltage, and comparably small difference in pretilt angle before and after application of an alternate current voltage. Therefore, we can expect that the PSA-LCD would be fabricated without the exposure process of the UV light. Moreover, the PSA-LCD fabricated by the proposed method would be a small level of image sticking. [ABSTRACT FROM AUTHOR]

We propose a novel method to fabricate a vertical alignment (VA) of liquid crystal (LC) molecules without using a conventional alignment layer such as polyimide film. The method produces the vertical alignment polymer layer (VAPL) by polymerisation of a monomer or mixed monomers including in the LC layer aboveTNIof the LC material. The VA mode LC cell with the VAPL (VAPL-LC cell) produced from the mixed monomers of acrylic acid 4-(4ʹ-octyloxy-biphenyl-4-yloxy)-butyl ester and 1,2-bis-(4-methacryloxy-phenyl)-2,2-dimethoxy-ethane-1-one exhibited enough level of alignment state and electro-optical property with high voltage holding ratio. We can expect that the VAPL-LC cell is useful for next-generation displays such as flexible liquid crystal displays because the method does not need the process including high temperature over 200°C. [ABSTRACT FROM AUTHOR]

Liquid crystal cells having polymer layers produced from copolymers of 4,4′-dimethacryloyl-oxy-biphenyl (4,4′-DMABiph) and anthracene-carrying monomers, 2,7-dimethacryloyl-oxy-anthracene (2,7-DMAAnth) and 2-methacryloyl-oxy-anthracene (2-MAAnth), were fabricated, and generation mechanism of residual direct current voltage (VrDC) was clarified. TheVrDCwas improved with the LC cells having the polymer layers produced from the copolymers of 4,4′-DMABiph and 2,7-DMAAnth due to large rate constant of polymerisation. In contrast, theVrDCwas increased with the LC cells having the polymer layers produced from the copolymer of 4,4′-DMABiph and 2-MAAnth. The increase in theVrDCwas derived from the increase in the concentration of polymerised- or unpolymerised-terminally radical and ion generated from 2-MAAnth. The results suggest that the monomers should show large rate constant of polymerisation with plural number of polymerised groups for improving theVrDC. [ABSTRACT FROM AUTHOR]

As a model of polymer-sustained-alignment liquid crystal display (PSA-LCD), the liquid crystal (LC) cells having the polymer layers produced from monomers of phenanthrene (Phen)-carrying monomers, 2,7-, 3,8-, 1,8- and 3,6-dimethacryloyl-oxy-phenanthrene (DMAPhen), were prepared and investigated image sticking phenomenon with evaluations of residual direct current voltage (VrDC) and difference in pretilt angle before and after application of alternate current voltage (Δtilt). TheVrDCvalues were small for the LC cells with the polymer layers produced from the Phen-carrying monomers used in this study. On the other hand, Δtilt depends on the molecular structure of the Phen-carrying monomer. The Δtilt values became small with increasing the linearity of the monomer structure for the Phen-carrying monomers. The findings would be useful for obtaining the small level of image sticking in the PSA-LCDs produced from the Phen-carrying monomers. [ABSTRACT FROM AUTHOR]