Variable spot size lenses and lighting systems

Abstract

Improved lighting devices and methods are provided. In many embodiments, the devices and methods provide the capability to change a spot of light projected onto a target surface. In other embodiments, the devices and methods are fixed-focus. In one embodiment a lens can have a lens body with anterior and posterior surfaces. The anterior surface can be adapted to receive light from a light source. The posterior surface can have a central portion and a peripheral portion. Some of the light from the light source can pass through the lens body and exit the central portion of the posterior surface via refraction. Some of the light from the light source can pass through the lens body and exit the peripheral portion of the posterior surface via both refraction and reflection at various surfaces of the lens.

1 - 75 . (canceled) 
     
     
         76 . A lens, comprising:
 a lens body disposed about an optical axis and characterized by a central segment and a peripheral segment, said central segment comprising a diffractive lens,   wherein for at least one position of the light source along the optical axis, at least a portion of light generated by the light source entering said peripheral segment through an anterior surface thereof exits the lens body via refraction through a posterior surface of said peripheral segment following successive reflections at said posterior and anterior surfaces of the peripheral segment.   
     
     
         77 . The lens of  claim 76 , wherein said central segment comprises an anterior surface adapted to receive light from the light source and a posterior surface through which light exits the lens body. 
     
     
         78 . The lens of  claim 77 , wherein said anterior surface of the central segment is configured to refract light from said light source incident thereon for entry into said lens body. 
     
     
         79 . The lens of  claim 78 , wherein said posterior surface of the central segment comprises said diffractive lens. 
     
     
         80 . The lens of  claim 76 , wherein said reflection at the posterior surface of the peripheral segment comprises total internal reflection. 
     
     
         81 . The lens of  claim 76 , wherein said central segment of the lens body provides a converging optical power. 
     
     
         82 . The lens of  claim 76 , wherein said posterior surface of the peripheral segment has a flat profile. 
     
     
         83 . The lens of  claim 76 , wherein said anterior surface of the peripheral segment has any of a substantially cup-shaped, parabolic, and elliptical profile. 
     
     
         84 . The lens of  claim 76 , wherein for said at least one position of the light source, said posterior surface of the peripheral segment reflects at least about 90% of the light incident thereon via a single passage through the lens body. 
     
     
         85 . A lens, comprising:
 a lens body disposed about an optical axis and characterized by a central segment and a peripheral segment, said central segment comprising a Fresnel lens,   wherein for at least one position of the light source along the optical axis, at least a portion of light generated by the light source entering said peripheral segment through an anterior surface thereof exits the lens body via refraction through a posterior surface of said peripheral segment following successive reflections at said posterior and anterior surfaces of the peripheral segment.   
     
     
         86 . The lens of  claim 85 , wherein said central segment comprises an anterior surface adapted to receive light from the light source and a posterior surface through which light exits the lens body. 
     
     
         87 . The lens of  claim 86 , wherein said anterior surface of the central segment is configured to refract light from said light source incident thereon for entry into said lens body. 
     
     
         88 . The lens of  claim 85 , wherein said posterior surface of the central segment comprises said Fresnel lens. 
     
     
         89 . The lens of  claim 85 , wherein said reflection at the posterior surface of the peripheral segment comprises total internal reflection. 
     
     
         90 . The lens of  claim 85 , wherein said central segment of the lens body provides a converging optical power. 
     
     
         91 . The lens of  claim 85 , wherein for said at least one position of the light source, said posterior surface of the peripheral segment reflects at least about 90% of the light incident thereon via a single passage through the lens body. 
     
     
         92 . A lens, comprising:
 a lens body disposed about an optical axis and characterized by a central segment and a peripheral segment, said central segment comprising a kinoform,   wherein for at least one position of the light source along the optical axis, at least a portion of light generated by the light source entering said peripheral segment through an anterior surface thereof exits the lens body via refraction through a posterior surface of said peripheral segment following successive reflections at said posterior and anterior surfaces of the peripheral segment.   
     
     
         93 . The lens of  claim 92 , wherein said central segment comprises an anterior surface adapted to receive light from the light source and a posterior surface through which light exits the lens body. 
     
     
         94 . The lens of  claim 93 , wherein said anterior surface of the central segment is configured to refract light from said light source incident thereon for entry into said lens body. 
     
     
         95 . The lens of  claim 92 , wherein said posterior surface of the central segment comprises said kinoform. 
     
     
         96 . The lens of  claim 92 , wherein said reflection at the posterior surface of the peripheral segment comprises total internal reflection. 
     
     
         97 . The lens of  claim 92 , wherein said central segment of the lens body provides a converging optical power. 
     
     
         98 . The lens of  claim 92 , wherein for said at least one position of the light source, said posterior surface of the peripheral segment reflects at least about 90% of the light incident thereon via a single passage through the lens body.