Patent ID: 8243251

Claim:
A liquid crystal Fresnel lens comprising: a concentrically segmented ring-shaped electrode group, which includes a first plurality of ring-shaped electrodes and a second plurality of ring-shaped electrodes; a common electrode disposed opposite said ring-shaped electrode group; a liquid crystal layer provided between said ring-shaped electrode group and said common electrode; a first lens segment region which includes said first plurality of ring-shaped electrodes from said ring-shaped electrode group, and which forms a first retardation distribution by utilizing said first plurality of ring-shaped electrodes; and a second lens segment region which includes said second plurality of ring-shaped electrodes from said ring-shaped electrode group, said second plurality of ring-shaped electrodes being located outwardly of said first plurality of ring-shaped electrodes, and which forms a second retardation distribution by utilizing said second plurality of ring-shaped electrodes, wherein each retardation level in said first and second retardation distributions is formed by a single ring-shaped electrode, a Fresnel lens-like retardation distribution is formed across said first and second lens segment regions, and the number of retardation levels in said second retardation distribution formed in said second lens segment region is smaller than that in said first retardation distribution formed in said first lens segment region.