ES313378A3 - An elevated projector of slides. (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

An overhead slide projector apparatus, suitable for use in the front of a classroom for projecting on a vertical screen a luminous image of a slide held horizontally and which, when in position for said projection, comprises: A case similar to a box, a light source mounted in said case, a transparent member mounted in said case to provide a substantially horizontal projection platform, a condenser lens located below and adjacent said transparent member and above said light source to collect light from said source and directing it upwards through said transparent member in a cone of light having an incident axial ray, a projection head consisting essentially of a pair of converging meniscus lenses, which are small relative to said condenser lens, and a means reflectors that provides a single planar reflective surface located between said s meniscus lenses and in a triangular arrangement with them, whose concave surfaces face the said reflecting surface, and means that locate said projection head above said projection platform, so that said axial incident ray passes through one of said meniscus lenses generally radial to the medial curvature thereof and directly to said reflecting surface so that it is reflected by it directly towards and substantially through the center of the other of said meniscus lens, and at a height such that the Actual image of said light source produced by said condenser lens is substantially between said pair of meniscus lenses. (Machine-translation by Google Translate, not legally binding)