Copier lens of reflex design

An optical system of a reflex copier lens including a combination of glass and plastic elements, at least one of the elements being plastic and having aspheric surfaces, the system having substantially the following specifications:

• Efl = 7.4388 inches (188.94mm)
• Half Angle of Field = 25.92 degrees
• Aperture = f/5.02 (All dimensions in Inches)
• ______________________________________ Lens Radii Thickness Spacing N.sub.D V ______________________________________ L.sub.1 R.sub.1 = INF. T.sub.1 = .2350 1.522 59.5 R.sub.2 = INF. S.sub.1 = .0100 L.sub.2 R.sub.3 = +13.3610 T.sub.2 = .3090 1.755 27.6 R.sub.4 = - 8.0685 S.sub.2 = .0230 L.sub.3 *R.sub.5 = + 4.10036 T.sub.3 = .3240 1.490 57.4 *R.sub.6 = - 4.01434 S.sub.3 = .8560 L.sub.4 R.sub.7 = + 9.4050 T.sub.4 = .1660 1.589 61.3 R.sub.8 = +39.1650 -- L.sub.4R R.sub.9 = +39.1650 T.sub.5 = .1660 1.589 61.3 R.sub.10 = + 9.4050 S.sub.4 = .8560 L.sub.3R *R.sub.11 = -4.01434 T.sub.6 = .3240 1.490 57.4 *R.sub.12 = +4.10036 S.sub.5 = .0230 L.sub.2R R.sub.13 = - 8.0685 T.sub.7 = .3090 1.755 27.6 R.sub.14 = +13.3610 S.sub.6 = 13.5345 ______________________________________
• wherein the first column lists the lens elements numerically, the second column lists the respective radii and vertex radii of the aspheric surfaces *R.sub.5, *R.sub.6, *R.sub.11, and *R.sub.12 of the elements, using the convention that convex surfaces have positive radii and concave surfaces have negative radii, the third column lists the respective thicknesses of the elements, the fourth column lists the axial spacings between adjacent elements and the film plane, and the fifth and sixth columns list respectively the refractive and dispersive indices of the optical materials of the lens system.