Illuminating system for overhead projectors

摘要

The illuminating system for an overhead projector has an illuminating mirror which is constructed in the form of a silvered section (2) of an ellipsoid of rotation. The projection lamp (1) is situated at one focal point of this section (2), and the projection lens (3) is situated at the other focal point. The conventional stepped lens is thus replaced here by an illuminating mirror which can be produced by injection moulding or deep drawing. <IMAGE>