Wide angle lens

Claim 2

A wide angle lens comprising, in the order from the object side; a divergent first component consisting of a negative meniscus lens element having its convex surface facing the object side, a compositely convergent second component consisting of three lens elements cemented together and which are in the order from the object side, a biconvex lens element, biconcave lens element and a positive lens element, the center thickness of said biconvex lens element of said second component being greater than the separation between said first and said second components, a compositely convergent third component consisting of two lens elements and which are in the order from the object side, a positive lens element and a positive meniscus lens element having its convex surface facing the image side, and a divergent fourth component consisting of a negative meniscus lens element having its convex surface facing the image side, the separation between said fourth and said third components being less than that between said first and said second components.

Claim 3

A wide angle lens as defined in claim 1, wherein the refractive index of the biconvex lens element of said second component is greater than that of the biconcave lens of the same component.

Claim 4

A wide angle lens as defined in claim 2, satisfying the following conditions: |r.sub.4 |<r.sub.3, where r 3 represents the curvature radius of the object side surface of said biconvex lens element of said second component, and r 4 the curvature radius of the image side surface of said biconvex lens element.

Claim 5

A wide angle lens as defined in claim 2, wherein numerical data are as follows: ______________________________________ total focal length: f = 100 aperture ratio 1:4.5 back focal distance: Bf = 69.673 r1 = 106.395 dl = 1.76 ndl = 1.57250 νdl = 57.5 r2 = 26.461 d2 = 17.86 r3 = 35.943 d3 = 27.23 nd2 = 1.80218 νd2 = 44.4 r4 = -31.610 d4 = 0.88 nd3 = 1.67163 νd3 = 38.8 r5 = 45.204 d5 = 3.31 nd4 = 1.52000 νd4 = 70.1 r6 = 2425.579 d6 = 3.64 r7 = -254.686 d7 = 9.37 nd5 = 1.60717 νd5 = 40.2 r8 = -16.406 d8 = 17.31 nd6 = 1.71736 νd6 = 29.5 r9 = -45.424 d9 = 11.03 r10 = -25.391 d10 = 1.65 nd7 = 1.73350 νd7 = 51.0 r11 = -44.543 Σd = 94.04 ______________________________________

Claim 6

A wide angle lens as defined in claim 2, wherein numerical data are as follows: ______________________________________ total focal length: f = 100 aperture ratio 1:4.5 back focal distance: Bf = 69.238 r1 = 108.684 dl = 1.97 ndl = 1.57250 νdl = 57.5 r2 = 26.711 d2 = 17.50 r3 = 35.921 d3 = 26.97 nd2 = 1.80218 νd2 = 44.4 r4 = -32.868 d4 = 0.92 nd3 = 1.67163 νd3 = 38.8 r5 = 45.132 d5 = 3.42 nd4 = 1.52000 νd4 = 70.1 r6 = 1644.737 d6 = 4.21 r7 = -271.053 d7 = 9.21 nd5 = 1.60717 νd5 = 40.2 r8 = -16.487 d8 = 17.37 nd6 = 1.71736 νd6 = 29.5 r9 = -46.184 d9 = 11.05 r10 = -25.645 d10 = 1.97 nd7 = 1.73350 νd7 = 51.0 r11 = -43.786 Σd = 94.57 ______________________________________

Claim 7

A wide angle lens as defined in claim 2, wherein numerical data are as follows: ______________________________________ total focal length: f = 100 aperture ratio 1:4.0 back focal distance: Bf = 70.197 r1 = 114.091 dl = 2.42 ndl = 1.56883 νdl = 56.0 r2 = 28.333 d2 = 19.09 r3 = 37.348 d3 = 28.03 nd2 = 1.80218 νd2 = 44.4 r4 = -35.515 d4 = 1.06 nd3 = 1.67163 νd3 = 38.8 r5 = 45.455 d5 = 3.79 nd4 = 1.52000 νd4 = 70.1 r6 = 939.394 d6 = 4.70 r7 = -351.515 d7 = 7.58 nd5 = 1.56732 νd5 = 42.8 r8 = -18.121 d8 = 18.33 nd6 = 1.69895 νd6 = 30.0 r9 = -46.061 d9 = 10.53 r10 = -25.348 d10 = 2.27 nd7 = 1.58267 νd7 = 46.5 r11 = -46.874 Σd = 97.8 ______________________________________