Patent ID: 6351058
Filing Date: 2002-02-26
Classification: H01J

Abstract:
An improved xenon arc lamp with a cathode and anode electrode in a xenon atmosphere, the improvements comprising:an envelope comprising a bowled lower metal body joined at its outer circumference to an oppositely bowled upper ceramic body at its outer circumference, and a sapphire window disposed in the middle of the ceramic body, and all symmetrically disposed around a central lamp axis; a lower concave mirror fully included in the lower metal body and coaxially disposed around an anode electrode and facing toward a window; an upper concave mirror fully included in the upper ceramic body and coaxially disposed around a cathode electrode and facing both the lower concave mirror and an inter-electrode gap; a convex apron mirror coaxially mounted on a stem of said cathode electrode between said inter-electrode gap and any cathode stem support, and facing said sapphire window away from said inter-electrode gap; and an interface between the upper and lower concave mirrors and which is disposed at a constant elevation angle relative to said inter-electrode gap; wherein, light rays emitted from said inter-electrode gap below said constant elevation angle will be reflected only off the lower concave mirror before exiting through said window to an external focus; and wherein, all light rays emitted from said inter-electrode gap above said constant elevation angle and that are emitted out said window to said focus are reflected only by the upper concave mirror to only the convex apron mirror.