Guide to UV Measurement
Lamps: Reflector Design
Typically, UV lamps have an elliptical reflector to focus the bulb energy on a line in front of the lamp face. The printed, coated, or decorated surface is typically passed through the high intensity focal zone of the reflector. This will maximize cure speed. For some specialized purposes, other reflector configurations, such as parabolic reflectors, and hybrid combinations are available. Reflectors made with special, multilayer dielectric coatings (called “cold mirrors” or dichroic reflectors ) can be incorporated in the lamp to absorb much of the infrared energy radiated by the bulb. This can significantly reduce the heating of the surface being processed.
It is important to note that tubular lamps utilize the shape of the reflector (elliptical, parabolic, or other) in one axis only . In the axis along the bulb, the radiant energy is not focused - in that axis, the energy is more isotropically radiated.