Patent ID: 8016451

Claim:
An optical system, comprising: a light source, a lens optically coupled to the light source for receiving light therefrom, said lens and the light source being movable relative to one another along an optical axis of the lens between a narrow beam position and a wide beam position, said lens having a lens body disposed about an optical axis and characterized by an anterior surface and a posterior surface, at least a portion of the anterior surface being adapted for receiving light from a light source, said posterior surface having a central portion and a peripheral portion, wherein for said narrow beam position the light received from the light source exits the lens primarily via refraction from said central portion of the posterior surface and for said wide beam position the light received from the light source exits the lens via refraction from said central portion and via refraction from said peripheral portion of the posterior surface following successive reflections from said peripheral portion of the posterior surface and a peripheral portion of the anterior surface.