Lens system for micro film

Claim 2

A lens system for micro film comprising a first negative cemented doublet lens component, a second positive lens component, a third positive lens component, a fourth positive lens component, a fifth positive lens component, a sixth negative cemented doublet lens component, a seventh negative meniscus lens component, an eighth cemented doublet meniscus lens component and a ninth positive meniscus lens component, and said lens system satisfying the following conditions: (1) -14f<r 7 <-11f (2) 0.31f<r 14 <0.35f (3) -1.2f<r 15 <-0.8f (4) -2.1f<r 16 <-2.0f wherein the reference symbols r 7 , r 14 , r 15 and r 16 represent radii of curvature on the image side surface of the third lens component, the image side surface of the sixth lens component, the object side surface and the image side surface of the seventh lens component, and the reference symbol f designates focal length of the entire lens system as a whole.

Claim 3

A lens system for micro film according to claim 1 having the following numerical data: ______________________________________ f = 1.0 β = 1/10 N.A = 0.30 ______________________________________ r.sub.1 = -1.6918 d.sub.1 = 0.3359 n.sub.1 = 1.50405 ν.sub.1 = 70.15 r.sub.2 = -2.5058 d.sub.2 = 0.1679 n.sub.2 = 1.67357 ν.sub.2 = 35.70 r.sub.3 = 7.4793 d.sub.3 = 1.3684 r.sub.4 = 34.4297 d.sub.4 = 0.2749 n.sub.3 = 1.64083 ν.sub.3 = 56.36 r.sub.5 = -2.9883 d.sub.5 = 0.0084 r.sub.6 = 2.5689 d.sub.6 = 0.3594 n.sub.4 = 1.64083 ν.sub.4 = 56.36 r.sub.7 = -13.5736 d.sub.7 = 0.0041 r.sub.8 = 1.2594 d.sub.8 = 0.2603 n.sub.5 = 1.64083 ν.sub.5 = 56.36 r.sub.9 = 2.4748 d.sub.9 = 0.0041 r.sub.10 = 0.9243 d.sub.10 = 0.2314 n.sub.6 = 1.64083 ν.sub.6 = 56.36 r.sub.11 = 1.1089 d.sub.11 = 0.0041 r.sub.12 = 0.7576 d.sub.12 = 0.2939 n.sub.7 = 1.58016 ν.sub.7 = 58.62 r.sub.13 = 4.9475 d.sub.13 = 0.1259 n.sub.8 = 1.67357 ν.sub.8 = 35.70 r.sub.14 = 0.3169 d.sub.14 = 0.3421 r.sub.15 = -0.8299 d.sub.15 = 0.1446 n.sub.9 = 1.67357 ν.sub.9 = 35.70 r.sub.16 = -2.0211 d.sub.16 = 0.0330 r.sub.17 = -2.4178 d.sub.17 = 0.0715 n.sub.10 = 1.54930 ν.sub.10 = 50.84 r.sub.18 = 0.4300 d.sub.18 = 0.1572 n.sub.11 = 1.66596 ν.sub.11 = 60.25 r.sub.19 = -0.8009 d.sub. 19 = 0.0278 r.sub.20 = 0.4379 d.sub.20 = 0.2079 n.sub.12 = 1.50405 ν.sub.12 = 70.15 r.sub.21 = 0.8048 ______________________________________ wherein the reference symbol f represents focal length of the entire lens system as a whole, the reference symbols r 1 through r 21 designate radii of curvature on the surfaces of the respective lens elements, the reference symbols d 1 through d 20 denote thicknesses of the respective lens elements and the airspaces therebetween, the reference symbols n 1 through n 12 represent refractive indices of the respective lens element for a line at a wavelength of 3650 A and the reference symbols ν 1 through ν 12 represent Abbe's numbers of the respective lens elements for the d line.

Claim 4

A lens system for micro film according to claim 1 having the following numerical data: ______________________________________ f = 1.0 β = 1/10 N.A = 0.30 ______________________________________ r.sub.1 = -1.7856 d.sub.1 = 0.2148 n.sub.1 = 1.64089 ν.sub.1 = 42.32 r.sub.2 = 1.2886 d.sub.2 = 0.3436 n.sub.2 = 1.64083 ν.sub.2 = 56.36 r.sub.3 = -38.9024 d.sub.3 = 1.3916 r.sub.4 = 41.5498 d.sub.4 = 0.2792 n.sub.3 = 1.64083 ν.sub.3 = 56.36 r.sub.5 = -3.4487 d.sub.5 = 0.0086 r.sub.6 = 2.5150 d.sub.6 = 0.3651 n.sub.4 = 1.64083 ν.sub.4 = 56.36 r.sub.7 = -11.3553 d.sub.7 = 0.0041 r.sub.8 = 1.4984 d.sub.8 = 0.2645 n.sub.5 = 1.64083 ν.sub.5 = 56.36 r.sub.9 = 2.7450 d.sub.9 = 0.0041 r.sub.10 = 1.0711 d.sub.10 = 0.2350 n.sub.6 = 1.64083 ν.sub.6 = 56.36 r.sub.11 = 1.3387 d.sub.11 = 0.0041 r.sub.12 = 0.8123 d.sub.12 = 0.3942 n.sub.7 = 1.58016 ν.sub.7 = 58.62 r.sub.13 = -3.4653 d.sub.13 = 0.0828 n.sub.8 = 1.67357 ν.sub.8 = 35.70 r.sub.14 = 0.3485 d.sub.14 = 0.2898 r.sub.15 = -1.1694 d.sub.15 = 0.1469 n.sub.9 = 1.67357 ν.sub.9 = 35.70 r.sub.16 = -2.0685 d.sub.16 = 0.0335 r.sub.17 = -1.9939 d.sub.17 = 0.0726 n.sub.10 = 1.54930 ν.sub.10 = 50.84 r.sub.18 = 0.4560 d.sub.18 = 0.1597 n.sub.11 = 1.66596 ν.sub.11 = 60.25 r.sub.19 = - 0.8228 d.sub.19 = 0.0282 r.sub.20 = 0.4608 d.sub.20 = 0.2804 n.sub.12 = 1.50405 ν.sub.12 = 70.15 r.sub.21 = 0.6119 ______________________________________ wherein the reference symbol f represents focal length of the entire lens system as a whole, the reference symbols r 1 through r 21 designate radii of curvature on the surfaces of the respective lens elements, the reference symbols d 1 through d 20 denote thicknesses of the respective lens elements and the airspaces therebetween, the reference symbols n 1 through n 12 represent refractive indices of the respective lens element for a line at a wavelength of 3650 A and the reference symbols ν 1 through ν 12 represent Abbe's numbers of the respective lens elements for the d line.