Yasuo Umezu

A Novel Liquid Crystal Display: A Randomly-Oriented Nematic Liquid Crystal Display (RON-LCD)

Abstract A novel liquid crystal display: a Randomly-Oriented Nematic Liquid Crystal Display (RON-LCD) is demonstrated and the electro-optical properties are discussed compared with those of a Polymer Network Liquid Crystal Display (PN-LCD). The Homeotropic-RON-LCD with an 8 μm network layer and a 2 μm no-network layer has sufficient opaqueness at off-state and can be driven by lower voltage than the d = 10 μm PN-LCD. The resistivity of RON-LCD is improved by using a liquid crystal PN-011.

Liquid Crystal Mixtures with Low Birefringence for Active-Matrix LCD

The liquid crystal (LC) mixtures with fused ring systems such as Decahydronaphthalenes and Tetrahydronaphthalenes for reflective or transflective active-matrix liquid crystal display (AM-LCD) have higher durability than LC mixtures with ester-components. These LC mixtures also have some problems such as low nematic-isotropic transition temperature TNI and high driving voltage. The improvement for driving voltage was carried out by using Tetrahydronaphthalene-component with moderate birefringence Δn and large dielectric anisotropy Δ˜. However, It was difficult to obtain LC mixtures with sufficiently low driving voltage, because of low TNI and the comparatively high Δn of tetrahydronaphthalene. We have improved these problems by introducing some newly developed LC components and optimization. We obtained the LC mixtures with low Δn and low driving voltage; less than 0.075 of Δn and about 4 V or less of driving voltage. These LC mixtures have high durability with stable nematic phase at low temperature.

32.1: Properties of Fluorinated Liquid Crystalline Naphthalenes

We have synthesized a new series of fluorinated liquid crystalline napthalenes having fluorinated naphthalene moiety at the end of molecule and compared the properties to the previously presented naphthalenes with a similar chemical structure. The new fluorinated liquid crystalline naphthalene with calculated smaller molecular volume shows lower rotational viscosity. Moreover, the naphthalene with calculated larger dipole moment shows larger dielectric anisotropy.