Optical image-magnifying element, information-display unit comprising such an element, and information-display panel comprising a plurality of such units

摘要

An image-magnifying element is desribed for use in a large-screen panel for assembling constituent pictures displayed on separate picture tubes (2) to form a new unitary picture (30) without discontinuities. The element comprises a Fresnel lens (6) whose surface (7, 8) has a curvature which is concentric with that of the faceplate (5) of the picture tube. The Fresnel lens is provided with curved upright side walls (11, 12) of a transparent material, whose outer surfaces (15) are reflecting and whose edges (13, 14) have a curvature corresponding to that of the picture tube.