Liquid crystal fresnel lens

Abstract

The present invention is directed to the provision of a liquid crystal Fresnel lens that achieves high focusing performance. The liquid crystal Fresnel lens according to the present invention includes a concentrically segmented ring-shaped electrode group, a common electrode disposed opposite the ring-shaped electrode group, a liquid crystal layer provided between the ring-shaped electrode group and the common electrode, a first lens segment region which includes a first plurality of ring-shaped electrodes from the ring-shaped electrode group, and which forms a first retardation distribution by utilizing the first plurality of ring-shaped electrodes, and a second lens segment region which includes a second plurality of ring-shaped electrodes from the ring-shaped electrode group, the second plurality of ring-shaped electrodes being located outwardly of the first plurality of ring-shaped electrodes, and which forms a second retardation distribution by utilizing the second plurality of ring-shaped electrodes, wherein a Fresnel lens-like retardation distribution is formed across the first and second lens segment regions, and the number of the second plurality of ring-shaped electrodes is made smaller than the number of the first plurality of ring-shaped electrodes.