title: Liquid-crystal variable-focus lenses with a spatially-distributed tilt angles.
abstract: A pretilt angle controlling method by the density of rubbings using a tiny stylus is proposed. The control of the surface pretilt angle is achieved by rubbing a side-chain type polyimide film for a homeotropic alignment. Smooth liquid crystal (LC) director distribution in the bulk layer is successfully obtained even though the rough surface orientation. This approach is applied to LC cylindrical and rectangular lenses with a variable-focusing function. The distribution profile of the rubbing pitch (the reciprocal of the rubbing density) for small aberration is determined to be quadratic. The variable focusing function is successfully achieved in the LC rectangular lens, and the voltage dependence of the focal length is tried to be explained by the LC molecular reorientation behavior.
authors: Department of Electronics and Information Systems, Faculty of Systems Science and Technology, Akita Prefectural University, Yurihonjo, Akita, Japan. mhonma@akita-pu.ac.jp
authors: Michinori
authors: M
authors: Honma
authors: Toshiaki
authors: T
authors: Nose
authors: Satoshi
authors: S
authors: Yanase
authors: Rumiko
authors: R
authors: Yamaguchi
authors: Susumu
authors: S
authors: Sato
mesh_terms: D004867:Equipment Design; D007909:Lenses; D008027:Light; D050866:Liquid Crystals; D008853:Microscopy / Q000379:methods; D018625:Microscopy, Atomic Force; D055095:Optics and Photonics; D012031:Refractometry / Q000379:methods