Patent ID: 8451408

Claim:
An electrically tunable liquid crystal lens set comprising: a plurality of liquid crystal lenses, each of the liquid crystal lenses comprising: a planar liquid crystal layer supported between an opposed pair of transparent, insulating, alignment layers; a first planar electrode formed of a transparent conductive material supported adjacent to one of the alignment layers on the opposite side of the liquid crystal layer; a second transparent conductive electrode disposed on the second alignment layer on the side opposite to the liquid crystal layer, the second electrode comprising only one central tip electrode, wherein the liquid crystal layer, the first electrode, and the second electrode are stacked along a vertical projective direction; and a variable voltage power supply connected to the first and second electrodes so as to impose a nonhomogeneous electric field on the liquid crystal layer, the field having a maximum intensity at a center of the electrodes and decreasing toward the edges of the electrodes, so that the refractive index of the liquid crystal layer is adjusted in a nonhomogeneous manner to provide a lens effect to light passing through the liquid crystal lens, the focal length of the lens being a function of the applied voltage between the first and the second electrodes; wherein the liquid crystal lenses overlap to each other along the vertical projective direction.