Integrally focused low ozone illuminator

Abstract

A high pressure xenon arc illuminator bulb having a sapphire window generates a broad band of ultraviolet, visible and infrared radiation extending from about 180 nanometers to about 2000 nanometers. The emitted radiation in the range from about 180 to about 200 nanometers, in passing through the oxygen in the air, causes the molecules of oxygen in the form O.sub.2 to recombine to produce ozone, O.sub.3. Ozone is toxic. In the invention, a lens barrel, which holds a sapphire condensing lens, is joined to the xenon arc illuminator bulb with a lighttight and also hermetic connection. Thus, the condensing lens is optically rigid with the illuminator bulb and the ozone formed within the lens barrel is not released to the ambient environment, even though its local concentration within the lens barrel becomes high. Furthermore, the ozone confined within the lens barrel acts as an absorption filter for all of the wavelengths in the 180 to 200 nanometer band which are capable of producing ozone. The ultraviolet and other radiation leaving the sapphire condensing lens therefore does not produce toxic ozone in the ambient environment.

Dependencies are inferred from the claim text.