US Patent 8371710 Focusing lens system

A lens for a flashlight or other lighting unit provides for focusing light from a source, such as an LED, to provide a light beam adjustable between a spot beam and a wide beam. The lens includes a lens body with a front face, a rear LED-receiving well, and a side surface extending between the front face and the rear well. The front face includes a central surface surrounded by an annular concave surface. The rear well includes a space for the LED to be adjusted in position. The rear well space is defined by a concavely-curved sidewall and a concavely-curved base. The concave curvature of the sidewall and base may be Bezier curves.