Optical system for a fresnel lens light, especially for a spotlight or floodlight

摘要

The optical system for the Fresnel lens light has an ellipsoidal reflector (1), a light source (2) and a Fresnel lens (3). The distance (a) between the Fresnel lens (3) and the reflector (1) is related to the distance (b) between the light source (2) and the reflector (1) and is determined by the selected aperture angle for the propagated light beam, e.g. to provide spotlight or floodlight. The distance (b) is adjusted by moving the light source (2) from a first focal point (F1) in a direction toward or away from the vertex (V) of the reflector (1). The ellipsoidal reflector (1) is made of a metallic material or a transparent material. At least one of the respective surfaces on opposite sides of the reflector has a number of thin layers. Surfaces of the at least one Fresnel lens and/or the reflector can be structured to provide more uniform illumination of a given area. The optical system is useful for lights for film, stage, studio and photography.