Liquid Crystal Lens Prepared Using Molecular Orientation Effects at the Alignment Layers

摘要

Several types of liquid crystal (LC) lenses with variable focusing functions by applying an external electric field have been reported. We propose a new type of LC lens using the molecular orientation effects and resulting elastic force of LC director. The hole-patterned alignment area is treated for LC molecules to align parallel or perpendicular to the substrate coated with transparent electrodes, and outside area is treated to be an inverse alignment state. The surface of another substrate is coated with a homeotropic alignment layer. When the diameter of the hole pattern is nearly equal or less than the LC thickness, the distribution of the refractive index becomes bell-shaped and the LC cell behaves like an optical lens in the absence of the applied voltage. The focal length can also be varied by applying a voltage across the transparent electrodes.