ABSTRACT
New polymer-sustained-alignment liquid-crystal-displays (PSA-LCDs) with photo-alignment layers are proposed in this study. The fabrication process of the new PSA-LC cell is followings; a photo-alignment treatment is firstly conducted by exposing polarised UV from oblique direction to the photo-alignment layer. After construction of the LC cell having monomers in a LC layer, unpolarised UV is exposed for forming a polymer layer. During the exposure of the unpolarised UV, application of electric-field is not necessary because the pretilt angle is determined by the photo-alignment treatment. In order to avoid a shift of the pretilt angle during the unpolarised UV exposure, a relatively fast rate constant of polymerisation is important. Furthermore, residual-direct-current-voltage (VrDC), which is one of image sticking parameters, is also affected by the rate constant of the polymerisation, and the VrDC becomes small with increasing the rate constant. In contrast, the shift of the pretilt angle (Δtilt), which is another image sticking parameter, depends on molecular structures of the monomers, and the Δtilt becomes small for the monomers with linear structure between a core unit and polymerisable units. The results indicated that the monomer 2,7-dimethacryloyl-oxy-phenanthrene would be suitable for fabrication and small level of the image sticking of the PSA-LC cells with the photo-alignment layers.
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Disclosure statement
No potential conflict of interest was reported by the author(s).