Lens assembly

Abstract

A lens assembly for producing an image of an object includes a plurality of lenses constructed and arranged to provide a high resolution image, without requiring focusing, of any object within the lens assembly's field of view that is greater than approximately one inch away from the lens assembly, thus providing a constant focus lens assembly. In one embodiment, the plurality of lenses cooperate to provide an effective focal length of approximately 3.53 mm in air, an F number of 11.2 and an angle of view of approximately 34 degrees.

What is claimed is:  
     
         1 . A lens assembly for producing an image of an object, the lens assembly comprising: 
 a plurality of lenses constructed and arranged to produce an optically suitable image of any object, within a field of view of the lens assembly, that is greater than approximately one inch away from the lens assembly without requiring focusing, thereby providing a constant focusing lens assembly.    
     
     
         2 . The lens assembly of  claim 1 , wherein the plurality of lenses cooperate to provide an effective focal length of 3.53 mm in air, an F number of 11.2 and an angle of view of 34 degrees.  
     
     
         3 . The lens assembly of  claim 1 , wherein the plurality of lenses cooperate to provide an effective focal length of 3.53 mm in air.  
     
     
         4 . The lens assembly of  claim 1 , wherein the plurality of lenses cooperate to provide an F number of 11.2.  
     
     
         5 . The lens assembly of  claim 1 , wherein the plurality of lenses cooperate to provide an angle of view of 34 degrees.  
     
     
         6 . The lens assembly of  claim 1  having both a diameter and a length of less than 5 mm.  
     
     
         7 . The lens assembly of  claim 1  having a diameter of less than 5 mm.  
     
     
         8 . The lens assembly of  claim 1  having a length of less than 5 mm.  
     
     
         9 . The lens assembly of  claim 1 , wherein the optically suitable image is a high resolution image.  
     
     
         10 . The lens assembly of  claim 1 , comprising, in order from an object side: 
 a distal lens having a convex surface and a concave surface, the convex surface being proximate the object side;    a doublet lens in optical communication with the distal lens, the doublet lens having a concave surface and a convex surface, the concave surface of the doublet lens being proximate the concave surface of the distal lens; and    a bi-convex proximal lens in optical communication with the doublet lens.    
     
     
         11 . The lens assembly of  claim 10 , wherein the distal lens is a first distal lens, and wherein the lens assembly further comprises a second distal lens in optical communication with the first distal lens between the object side and the first distal lens, the second distal lens having a concave surface proximate the convex surface of the first distal lens.  
     
     
         12 . The lens assembly of  claim 10 , wherein the second distal lens is formed from a polycarbonate material having a thickness of approximately 0.38 mm.  
     
     
         13 . The lens assembly of  claim 10 , wherein: 
 the distal lens has a thickness of approximately 0.53 mm, the convex surface of the distal lens has a radius of curvature of approximately 1.3 mm and the concave surface of the distal lens has a radius of curvature of approximately 2.38 mm;    the doublet lens has a thickness of approximately 1.58 mm, the concave surface of the doublet lens has a radius of curvature of approximately 0.95 mm and the convex surface of the doublet lens has a radius of curvature of approximately 1.72 mm; and    the bi-convex proximal lens has a thickness of approximately 1.5 mm, each convex surface of the bi-convex proximal lens having a radius of curvature of approximately 6.06 mm.    
     
     
         14 . The lens assembly of  claim 10 , wherein an interior surface of the doublet lens has a convex surface having a radius of curvature of approximately 1.05 mm, and the doublet lens includes a first doublet lens having a thickness of 0.92 mm and a second doublet lens having a thickness of 0.66 mm.  
     
     
         15 . The lens assembly of  claim 14 , wherein the distal lens and the second doublet lens each has an index of refraction of approximately 1.785 and a V number of approximately 26.1 and the first doublet lens and the biconvex proximal lens each has an index of refraction of approximately 1.639 and a V number of approximately 55.4.  
     
     
         16 . The lens assembly of  claim 1 , in combination with a charge coupled device, wherein light rays from the object side are directed by the lens assembly so that they are incident upon a surface of the charge coupled device at an angle that is approximately perpendicular to the surface of the charge coupled device.  
     
     
         17 . A camera comprising a lens assembly according to  claim 1 .  
     
     
         18 . An optical imaging system comprising a lens assembly according to  claim 1 .  
     
     
         19 . A videoscope comprising a lens assembly according to  claim 18 .  
     
     
         20 . A surgical/diagnostic imaging device comprising a lens assembly according to  claim 18 .  
     
     
         21 . An aircraft monitoring system comprising an optical imaging system according to  claim 18 , wherein at least the lens assembly is mounted to a surface of an airplane and arranged to view a portion of the airplane.  
     
     
         22 . The lens assembly according to  claim 10 , further comprising an outer lens formed from a polycarbonate material having a radius of curvature of 5 mm, a thickness of 0.381 mm, and a diameter of 10 mm.  
     
     
         23 . The lens assembly of  claim 10 , wherein the outer lens is formed as part of a housing for the lens assembly.  
     
     
         24 . The lens assembly of  claim 1 , wherein the lens assembly is adapted to cooperate with an imaging device.  
     
     
         25 . The lens assembly of  claim 24 , wherein the imaging device is a charge coupled device.  
     
     
         26 . The lens assembly of  claim 1 , wherein the plurality of lenses comprises only four lenses.  
     
     
         27 . The lens assembly of  claim 26 , wherein two of the four lenses are coupled to form a doublet lens.  
     
     
         28 . A lens assembly for producing an image of an object, the lens assembly comprising: 
 a plurality of lenses cooperating to provide an effective focal length of approximately 3.53 mm in air, an F number of approximately 11.2 and an angle of view of approximately 34 degrees.    
     
     
         29 . The lens assembly of  claim 28  having both a diameter and a length of less than 5 mm.  
     
     
         30 . The lens assembly of  claim 28  having a diameter of less than 5 mm.  
     
     
         31 . The lens assembly of  claim 28  having a length of less than 5 mm.  
     
     
         32 . The lens assembly of  claim 28 , comprising, in order from an object side: 
 a distal lens having a convex surface and a concave surface, the convex surface being proximate the object side;    a doublet lens in optical communication with the distal lens, the doublet lens having a concave surface and a convex surface, the concave surface of the doublet lens being proximate the concave surface of the distal lens; and    a bi-convex proximal lens in optical communication with the doublet lens.    
     
     
         33 . The lens assembly of  claim 32 , wherein the distal lens is a first distal lens, and wherein the lens assembly further comprises a second distal lens in optical communication with the first distal lens between the object side and the first distal lens, the second distal lens having a concave surface proximate the convex surface of the first distal lens.  
     
     
         34 . The lens assembly of  claim 32 , wherein the second distal lens is formed from a polycarbonate material having a thickness of approximately 0.38 mm.  
     
     
         35 . The lens assembly of  claim 32 , wherein: 
 the distal lens has a thickness of approximately 0.53 mm, the convex surface of the distal lens has a radius of curvature of approximately 1.3 mm and the concave surface of the distal lens has a radius of curvature of approximately 2.38 mm;    the doublet lens has a thickness of approximately 1.58 mm, the concave surface of the doublet lens has a radius of curvature of approximately 0.95 mm and the convex surface of the doublet lens has a radius of curvature of approximately 1.72 mm; and    the bi-convex proximal lens has a thickness of approximately 1.5 mm, each convex surface of the bi-convex proximal lens having a radius of curvature of approximately 6.06 mm.    
     
     
         36 . The lens assembly of  claim 32 , wherein an interior surface of the doublet lens has a convex surface having a radius of curvature of approximately 1.05 mm, and the doublet lens includes a first doublet lens having a thickness of 0.92 mm and a second doublet lens having a thickness of 0.66 mm.  
     
     
         37 . The lens assembly of  claim 32 , wherein the distal lens and the second doublet lens each has an index of refraction of approximately 1.785 and a V number of approximately 26.1 and the first doublet lens and the biconvex proximal lens each has an index of refraction of approximately 1.639 and a V number of approximately 55.4.  
     
     
         38 . The lens assembly of  claim 28 , in combination with a charge coupled device, wherein light rays from the object side are directed by the lens assembly so that they are incident upon a surface of the charge coupled device at an angle that is approximately perpendicular to the surface of the charge coupled device.  
     
     
         39 . A camera comprising a lens assembly according to  claim 28 .  
     
     
         40 . An optical imaging system comprising a lens assembly according to  claim 28 .  
     
     
         41 . A videoscope comprising a lens assembly according to  claim 40 .  
     
     
         42 . A surgical/diagnostic imaging device comprising a lens assembly according to  claim 40 .  
     
     
         43 . An aircraft monitoring system comprising an optical imaging system according to  claim 40 , wherein at least the lens assembly is mounted to a surface of an airplane and arranged to view a portion of the airplane.  
     
     
         44 . The lens assembly according to  claim 32 , further comprising an outer lens formed from a polycarbonate material having a radius of curvature of 5 mm, a thickness of 0.381 mm, and a diameter of 10 mm.  
     
     
         45 . The lens assembly of  claim 32 , wherein the outer lens is formed as part of a housing for the lens assembly.  
     
     
         46 . The lens assembly of  claim 28 , wherein the lens assembly is adapted to cooperate with an imaging device.  
     
     
         47 . The lens assembly of  claim 46 , wherein the imaging device is a charge coupled device.  
     
     
         48 . The lens assembly of  claim 28 , wherein the plurality of lenses comprises only four lenses.  
     
     
         49 . The lens assembly of  claim 48 , wherein two of the four lenses are coupled to form a doublet lens.