Enhancement of the Electrooptical Performance of NTN-LCD Embedded with Nanoparticles Exhibiting An Excellent Dispersion in the Host NLC
S. Kobayashi,1,* M. Akimoto,1 K.Takatoh,1 K.Takeishi,2 K.Kotani,2 H.Takatsu2 and Y. Yamashita3
1 Institute of Liquid Crystal and Department of Electrical Engineering, Sanyo-Onoda, Yamaguchi, Japan
2 DIC Corp., Ina, Kita-adachi, Saitama, Japan
3 Nippon Aerosil Co., Ltd., Yokkaichi, Mie, Japan
We have established a technique for getting a long term stable dispersion of the nanoparticles of AEROSIL®812 and 300 (EVONIK)[1] in an NLC, NTN-02 (DIC) kept in a bottle by making a coexisting of a chiral agent AH-01 (DIC) with these NPs. And we get the saturated sedimentation height (SSH) of 80% of the whole height of the NLC by choosing the value of the pitch of the chiral agent to be 12mm. We obtained the reduction of the response time, τoff by -40% in our NTN-LCD both at 25℃ and 0℃ by doping NPs and chiral agent, where we chose the pitch p, over cell gap d to be p/d=4. A stable dispersion of NPs is also obtained in the host NLC of NTN-cell even with the pure NLC, NTN-02 especially when we use alignment PI films of SE-8292(Nissan Chem. Ind.) and this NTN-cell exhibits the reduction of its threshold voltage by -7%; this corresponds to the reduction of order parameter by -14% and this shift of the Vth is reproduced by raising temperature by 10℃ and the temperature is called Kobayashi temperature.
We also conducted a research of field sequential color (FSC) LCD using an NLC, NTN-03(DIC) doped with the nanoparticles of AEROSIL®812(0.5wt%) and we got a tremendous enlargement of the color gamut in this FSC-LCD due to the increase of the response speed of our NTN-FSC-LCD embedded with NPs even at low temperature as shown in Fig.1. At room temperature the color gamut increases up to 139% of that of NTSC and even at -15℃ the color gamut is the equivalent that of LCD-TV using color filter.
Figure 1 Color gamut of LCDs
References:
[1] www.evonik.com
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* presenting author; E-mail: