Abstract

The problem is to project a 715 line TV raster onto a concave screen subtending 160° and to present to the viewing eye uniform illumination and resolution that matches visual acuity vs angle. The resolution requirement dictates that mapping of linear dimension into angle be about fifty times greater peripheral than central. The projection system includes a final fisheye that gives uniform linear-to-angle mapping and a relay lens that provides 50× increase of linear mapping from center to edge. The numerical aperture on the object side must similarly increase by the 50-to-1 ratio to fill the fisheye aperture and hence provide uniform illumination. The relay contains two pairs of spline surfaces; one pair surrounds a virtual object, the other a virtual image. Each of these four surfaces provides axial demagnification, but off-axis their curvatures change sign so that each provides peripheral magnification. This relay has a central A-stop, is telecentric on the object side, and nearly so on the other. Achromatization is provided by three splines buried between SK16 and F2 glasses.

© 1986 Optical Society of America