Arc lamp with a triplet reflector including a concave parabolic surface, a concave elliptical surface and a convex parabolic surface

摘要

An arc lamp embodiment of the present invention comprises a triplet set of annular reflectors that gather light from an arc created between an anode and a cathode into essentially parallel beams that exit along the longitudinal axis of the generally cylindrical lamp through a sapphire window. A first of the three reflectors has a concave parabolic shape that reflects light out along the lamp axis in one bounce. A second of the three reflectors has a concave elliptical shape with a rear projecting focus and is back to back with the first reflector such that the open bowls of the reflectors face in opposite directions along the axis of the lamp. A third of the three reflectors has a convex parabolic shape that receives light bounced from the second reflector and gives it a second bounce out through an opening in the first reflector and then through the window, parallel to the lamp axis. The third reflector is concentric with the first and second reflectors and its body bows into the bowl of the second reflector.