Fisheye projection lens system for 35mm motion pictures
AssigneeUniversity of Arizona Foundation
InventorRichard A. Buchroeder
Life of this patent
Estimating the term…
Abstract
A 180.degree. high resolution fisheye projection lens suitable for projecting images onto a hemispherical dome, such as a planetarium dome, includes a nine-element projection lens and a six-element relay lens. The relay lens serves to increase the distance between the film plane and the lens and eliminates the need for modifying the projector to provide clearance between the lens and the projector shutter mechanism. In addition, the relay lens may be modified to make the fisheye lens compatible with various film sizes without modifying the fisheye lens. A focused iris is used to mask portions of the projected image, and a nonuniformly acting fader is used to reduce back scatter and to stop down the lens to adjust the brightness of the projected image.
Claims10
A fisheye lens system having the design parameters, normalized for an 8mm focal length, F.sub.8, represented in the following table:
- ______________________________________ ELE- THICK- SEPAR- MENT n.sub.d .nu. RADIUS NESS ATION ______________________________________ I 1.607 56.7 R.sub.1 = 8.853 t.sub.1 = .220 S.sub.1 = 1.037 R.sub.2 = 1.181 II 1.607 56.7 R.sub.3 = 4.463 t.sub.2 = .150 S.sub.2 = 1.486 R.sub.4 = 1.181 III 1.620 36.4 R.sub.5 = 5.798 t.sub.3 = .300 S.sub.3 = 1.062 R.sub.6 = 3.308 IV 1.620 36.4 R.sub.7 = 6.869 t.sub.4 = .150 S.sub.4 = .100 R.sub.8 = 2.536 V 1.607 56.7 R.sub.9 = 2.018 t.sub.5 = .500 S.sub.5 = .100 R.sub.10 = 2.638 VI 1.607 56.7 R.sub.11 = 6.440 t.sub.6 = .550 S.sub.6 = .100 R.sub.12 = 1.309 VII 1.755 27.6 R.sub.13 = 1.113 t.sub.7 = .150 R.sub.14 = 4.728 ______________________________________
- wherein the Roman numerals I-VII identify the respective lens element from the long conjugate side to the short conjugate side, n.sub.d is the refractive index;
- .nu..sub.d is the dispersion number, R.sub.1 -R.sub.14 represent the radii of successive surfaces from the long conjugate side to the short conjugate side, and t.sub.1 -t.sub.7 and S.sub.1 -S.sub.6 represent the thicknesses of lens element and air spaces, respectively, from the long conjugate side to the short conjugate side, with all dimensions being expressed in inches, and wherein the design parameters may be renormalized to any other focal length, F.sub.n, by multiplying each of the surface radii, thicknesses and air spaces by the ratio F.sub.n /F.sub.8.
Dependencies are inferred from the claim text.