Illumination device consisting of a point-like light source, an ellipsoid reflector, a lens and a heat absorption filter

摘要

The downstream lens is a multifocal field lens (9) having a negative optical refractive power in the centre and a positive optical refractive power towards the rim. Its application permits the use of halogen ellipsoid reflector lamps with a lens downstream of the lamp and an absorption filter as illuminating system in, for example, miniature slide projectors or microfilm readers, without the attendant need to enlarge the overall volume. IMAGE