Tomoki Gunjima
Asahi Glass Co.
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Publication
Featured researches published by Tomoki Gunjima.
Liquid Crystal Displays and Applications | 1990
Yoshinori Hirai; Satoshi Niiyama; Hiroshi Kumai; Tomoki Gunjima
A new method to obtain liquid crystal and polymer composite(LCPC) material is reported. This material is a new electro-optic material which can control scattering and transparent states in an electric field. e obtained this material by the photo-polymerization-induced phase separation from liquid crystal and prepolymer mixture where both monomer and oligonier are used as prepolymer. We have found new type of phase diagram in this mixture which has a nematicisotropic line in addition to binodal and spinodal lines. Electro-optic properties of this material are strongly affected by the point on the phase diagram at which the polymerization-induced phase separation starts. This method enables us to control these properties such as voltage-transmittance characteristics. Typical devices using these materials are also shown. They have high contrast ratio and high transmittance in ON state and are suitable for display devices. Drive voltage can be reduced by optimizing this material and the device with high contrast ratio about 200:1 in low drive voltage below 6Vrms was obtained.
Japanese Journal of Applied Physics | 1997
Hiromasa Sato; Hiroki Hotaka; Tomoki Gunjima; Yuzuru Tanabe; Masahiro Hirano
A grating polarizing beam-splitter was developed using a newly synthesized UV curable liquid crystal. The fabricated device shows high diffraction efficiency (+1st order: 35.5%, -1st order: 31.9%) and transmittance (83.8%). The temperature dependence of diffraction efficiency variation was suppressed by about 5% within temperature range from 20 to 80°C because these device parameters become less sensitive to temperature variation as a result of photopolymerization.
Liquid Crystal Materials, Devices, and Applications IV | 1996
Hiroshi Kumai; Satoshi Niiyama; Yoshiharu Ooi; Shinya Tahara; Yoshinori Hirai; Tsuneo Wakabashi; Tomoki Gunjima
A phase separation under an applied electric field (PSUF treatment) in LCPC relaxes the energetic stress for dynamic operation of its device. Both higher dynamic response time and less hysteresis in dark gray scales which are significant issues in LCPC are achieved, since its treatment can control the interface between liquid crystal and matrix polymer without the damage to scattering in off state and contrast ratio. It is based on the morphological characteristic which is caused by the first step: a segregation of liquid crystal and ordering process of the liquid crystal under an applied field, and the second step: polymer/pre-polymer precipitation to maintain the early ordering of segregated liquid crystal. The essential structure of LCPC caused by the characteristic phase separation process, is characterized with confocal fluorescence microcopy, which also supports its process mechanism.
Archive | 1995
Tomoki Gunjima; Yoshiharu Ooi; Masao Ozeki; Hiroaki Ito; Hiroshi Hasebe; Tetsuro Matsumoto; Yutaka Nakagawa
Archive | 1987
Tomoki Gunjima; Hiroshi Kumai; Shoichi Tsuchiya; Kaoriko Masuda
Archive | 1988
Tomoki Gunjima; Hiroshi Kumai; Minoru Akatsuka; Shoichi Tsuchiya
Archive | 1976
Hiroshi Ukihashi; Tatsuro Asawa; Masaaki Yamabe; Tomoki Gunjima; Haruhisa Miyake
Archive | 1991
Yoshiharu Ooi; Tomoki Gunjima; Yoshinori Hirai
Archive | 1992
Yoshinori Hirai; Satoshi Niiyama; Hiroshi Kumai; Tomoki Gunjima
Archive | 1989
Tomoki Gunjima; Masanori Yuki; Masaya Kunigita; Yoshinori Hirai; Yukio Yoshikawa; Eiji Shidoji