We propose on a novel vertical configuration (VC) for a helix-deformed ferroelectric liquid cryst... more We propose on a novel vertical configuration (VC) for a helix-deformed ferroelectric liquid crystal (HDFLC) display that has fast response, high contrast, analog gray scale capability, and wide-viewing characteristics. In contrast to a conventional HDFLC in a planar geometry, smectic layers arrange themselves parallel to the substrates, and thus, extremely uniform alignment of molecules in large area is naturally achieved
Molecular Crystals and Liquid Crystals Science and Technology. Section A. Molecular Crystals and Liquid Crystals, 2001
We introduce a hybrid double layer for liquid crystal (LC) alignment into a multi-domain vertical... more We introduce a hybrid double layer for liquid crystal (LC) alignment into a multi-domain vertically aligned mode. A blend of polyimide (PI) and poly(vinyl cinnamate) (PVCi) was cast onto a preformed PI layer. After curing, PVCi was extracted by washing to yield a LC alignment layer with homogeneous micro-domains uniformly distributed over the homeotropic layer. The size of homogeneous domains was strongly influenced by the weight content of PVCi as well as the solvent of PVCi. The viewing angle of ±l30° with contrast ratio of 10:1 along the direction of 45° to a polarizer was obtained from hybrid double layer LC cells with no compensation film.
We present a new method of fabricating a vertically aligned liquid crystal display (LCD) using su... more We present a new method of fabricating a vertically aligned liquid crystal display (LCD) using surface relief gratings. A two dimensional surface gratings are produced on a photosensitive polymer by illuminating the UV light through a photomask. A multi-domain structure is obtained on the grating surface with the homeotropic alignment. The LCD configuration with such axially multi-domain structure along the surface relief exhibits excellent viewing characteristics.
We demonstrate a fully continuous liquid crystal (LC) grating device with the alternating semi-ci... more We demonstrate a fully continuous liquid crystal (LC) grating device with the alternating semi-circular alignment which exhibits the switching effect between the diffraction orders independent of the thickness of the LC cell. The continuous phase modulation in the LC grating with the rotational symmetry was achieved on a micro-imprinted surface where the semi-circular alignment of the LC was spontaneously produced. Our LC grating device in the hybrid geometry exhibited the perfect continuity of the phase retardation and the switchable diffraction with the diffraction efficiency of 44% at ±1st orders as a function of an applied voltage. It was found that the symmetry of the input polarization direction with respect to the grating patterns results in the interchange between two symmetric grating configurations.
We propose on a novel vertical configuration (VC) for a helix-deformed ferroelectric liquid cryst... more We propose on a novel vertical configuration (VC) for a helix-deformed ferroelectric liquid crystal (HDFLC) display that has fast response, high contrast, analog gray scale capability, and wide-viewing characteristics. In contrast to a conventional HDFLC in a planar geometry, smectic layers arrange themselves parallel to the substrates, and thus, extremely uniform alignment of molecules in large area is naturally achieved
Molecular Crystals and Liquid Crystals Science and Technology. Section A. Molecular Crystals and Liquid Crystals, 2001
We introduce a hybrid double layer for liquid crystal (LC) alignment into a multi-domain vertical... more We introduce a hybrid double layer for liquid crystal (LC) alignment into a multi-domain vertically aligned mode. A blend of polyimide (PI) and poly(vinyl cinnamate) (PVCi) was cast onto a preformed PI layer. After curing, PVCi was extracted by washing to yield a LC alignment layer with homogeneous micro-domains uniformly distributed over the homeotropic layer. The size of homogeneous domains was strongly influenced by the weight content of PVCi as well as the solvent of PVCi. The viewing angle of ±l30° with contrast ratio of 10:1 along the direction of 45° to a polarizer was obtained from hybrid double layer LC cells with no compensation film.
We present a new method of fabricating a vertically aligned liquid crystal display (LCD) using su... more We present a new method of fabricating a vertically aligned liquid crystal display (LCD) using surface relief gratings. A two dimensional surface gratings are produced on a photosensitive polymer by illuminating the UV light through a photomask. A multi-domain structure is obtained on the grating surface with the homeotropic alignment. The LCD configuration with such axially multi-domain structure along the surface relief exhibits excellent viewing characteristics.
We demonstrate a fully continuous liquid crystal (LC) grating device with the alternating semi-ci... more We demonstrate a fully continuous liquid crystal (LC) grating device with the alternating semi-circular alignment which exhibits the switching effect between the diffraction orders independent of the thickness of the LC cell. The continuous phase modulation in the LC grating with the rotational symmetry was achieved on a micro-imprinted surface where the semi-circular alignment of the LC was spontaneously produced. Our LC grating device in the hybrid geometry exhibited the perfect continuity of the phase retardation and the switchable diffraction with the diffraction efficiency of 44% at ±1st orders as a function of an applied voltage. It was found that the symmetry of the input polarization direction with respect to the grating patterns results in the interchange between two symmetric grating configurations.
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Papers by Sin-Doo Lee