Projection lens for retroprojection apparatus, has auxiliary lenses that emit diverging light beam towards plane screen, and hyperbolic mirror that is oriented such that it receives light from lenses on its convex surface

摘要

The projection lens has auxiliary lenses (L1) that emit a diverging light beam towards a plane screen (EC). A hyperbolic mirror (M1) is oriented such that it receives a light coming from the auxiliary lenses, on its convex surface. The hyperbolic mirror is situated completely on a side of a plane passing via a hyperbolic symmetric axis. The hyperbolic mirror is oriented to receive the beam reflected by a different mirror. An independent claim is also included for a retroprojection apparatus.