Varifocal lens

Abstract

A varifocal lens including a first liquid crystal layer; a first electrode portion disposed below the first liquid crystal layer and having a flat shape; a first non-uniform electric field generator which generates a non-uniform electric field in the first liquid crystal layer together with the first electrode portion, and the first non-uniform electric field generator including a second electrode portion having a flat shape.

What is claimed is: 
     
         1 . A varifocal lens comprising:
 a first liquid crystal layer;   a first electrode portion disposed below the first liquid crystal layer and having a flat shape;   a first non-uniform electric field generator which generates a non-uniform electric field in the first liquid crystal layer together with the first electrode portion, the first non-uniform electric field generator comprising a second electrode portion having a flat shape.   
     
     
         2 . The varifocal lens of  claim 1 , wherein the first non-uniform electric field generator further comprises a first resistance layer disposed between the second electrode portion and the first liquid crystal layer. 
     
     
         3 . The varifocal lens of  claim 2 , wherein the first resistance layer is formed of a semiconductor, an insulator, or a conductive polymer. 
     
     
         4 . The varifocal lens of  claim 2 , wherein the first resistance layer is configured to have an inhomogeneous resistivity. 
     
     
         5 . The varifocal lens of  claim 4 , wherein the first electrode portion is shaped so as to face an entire lower surface of the first liquid crystal layer, and
 wherein the second electrode portion is shaped so as to face an entire upper surface of the first liquid crystal layer.   
     
     
         6 . The varifocal lens of  claim 4 , wherein at least one of the first electrode portion and the second electrode portion comprises a structure in which a plurality of electrodes are spaced apart from each other and are arranged to have an overall flat structure. 
     
     
         7 . The varifocal lens of  claim 6 , wherein at least one of the first electrode portion and the second electrode portion comprises a structure in which a plurality of electrodes each having a fan shape are spaced apart from each other to form a circular shape. 
     
     
         8 . The varifocal lens of  claim 4 , wherein the first resistance layer is formed of a semiconductor or an insulator including a plurality of impurities that are conductive carriers, and
 wherein the impurities are irregularly distributed in the semiconductor or the insulator.   
     
     
         9 . The varifocal lens of  claim 4 , wherein the first resistance layer comprises a structure in which a plurality of material layers with different resistivity are perpendicularly stacked or horizontally arranged on an upper surface of the first liquid crystal layer. 
     
     
         10 . The varifocal lens of  claim 1 , wherein the first electrode portion is shaped so as to face an entire lower surface of the first liquid crystal layer, and
 wherein the second electrode portion is shaped such that an opening is formed in a central portion of the second electrode portion and the second electrode portion faces an edge portion of an upper surface of the first liquid crystal layer.   
     
     
         11 . The varifocal lens of  claim 1 , wherein at least one of the first electrode portion and the second electrode portion comprises a structure in which a plurality of electrodes are spaced apart from each other and are arranged to have an overall flat structure. 
     
     
         12 . The varifocal lens of  claim 11 , wherein the first electrode portion comprises a structure in which a plurality of electrodes each having a fan shape are spaced apart from each other to form a circular shape. 
     
     
         13 . The varifocal lens of  claim 11 , wherein the second electrode portion comprises a structure in which a plurality of electrodes that are each shaped like a fan of which an apex portion is cut and are spaced apart from each other to form a ring shape. 
     
     
         14 . The varifocal lens of  claim 10 , wherein the first non-uniform electric field generator further comprises a third electrode portion that is spaced apart from the second electrode portion and has a different flat shape from that of the second electrode portion. 
     
     
         15 . The varifocal lens of  claim 1 , wherein the first non-uniform electric field generator further comprises a first nanostructure layer disposed between the second electrode portion and the first liquid crystal layer and, the first nanostructure layer comprising a plurality of nano structures. 
     
     
         16 . The varifocal lens of  claim 15 , wherein each of the plurality of nano structures comprises any one of carbon nanotube (CNT), gold nanowire, ZnO nanowire, and Si nanowire. 
     
     
         17 . The varifocal lens of  claim 15 , wherein the plurality of nano structures has a non-uniform length distribution. 
     
     
         18 . The varifocal lens of  claim 17 , wherein the first electrode portion is shaped so as to face an entire lower surface of the first liquid crystal layer, and
 wherein the second electrode portion is shaped so as to face an entire upper surface of the first liquid crystal layer.   
     
     
         19 . The varifocal lens of  claim 17 , wherein at least one of the first electrode portion and the second electrode portion comprises a structure in which a plurality of electrodes are spaced apart from each other and are arranged to have an overall flat structure. 
     
     
         20 . The varifocal lens of  claim 19 , wherein at least one of the first electrode portion and the second electrode portion comprises a structure in which a plurality of electrodes each having a fan shape are spaced apart from each other to form a circular shape. 
     
     
         21 . The varifocal lens of  claim 15 , wherein the first electrode portion is shaped so as to face an entire lower surface of the first liquid crystal layer, and
 wherein the second electrode portion is shaped such that an opening is formed in a central portion of the second electrode portion and the second electrode portion faces an edge portion of an upper surface of the first liquid crystal layer.   
     
     
         22 . The varifocal lens of  claim 21 , wherein the plurality of nano structures have a uniform length distribution. 
     
     
         23 . The varifocal lens of  claim 15 , wherein at least one of the first electrode portion and the second electrode portion comprises a structure in which a plurality of electrodes are spaced apart from each other and are arranged to have an overall flat structure. 
     
     
         24 . The varifocal lens of  claim 23 , wherein the first electrode portion comprises a structure in which a plurality of electrodes each having a fan shape are spaced apart from each other to form a circular shape. 
     
     
         25 . The varifocal lens of  claim 24 , wherein the second electrode portion comprises a structure in which a plurality of electrodes that are each shaped like a fan of which an apex portion is cut and are spaced apart from each other to form a ring shape. 
     
     
         26 . The varifocal lens of  claim 1 , further comprising:
 a second liquid crystal layer disposed below the first electrode portion; and   a second non-uniform electric field generator which generates a non-uniform electric field in the second liquid crystal layer together with the first electrode portion, the second non-uniform electric field generator comprising a third electrode portion having a flat shape.   
     
     
         27 . The varifocal lens of  claim 26 , wherein the second non-uniform electric field generator further comprises a second resistance layer disposed between the second liquid crystal layer and the third electrode portion. 
     
     
         28 . The varifocal lens of  claim 26 , wherein the second non-uniform electric field generator further comprises a second nanostructure layer disposed between the second liquid crystal layer and the third electrode, the second nanostructure layer comprising a plurality of nano structures.