Photographic lens system for endoscopes

Claim 2

A photographic lens system for endoscopes comprising an eyepiece having a positive refracting power and an adapter lens to be arranged on the rear of said eyepiece for photographing, said adapter lens comprising a positive lens component, a negative lens component and a positive lens component and having positive refractive power as a whole, said photographic lens systems being so designed as to satisfy the following conditions (1) and (2): (1) 0.9≦|R 1 /R 2 |≦1.2 (2) 0.2≦|f n /f|≦0.3 wherein the reference symbols R 1 and R 2 represent radii of curvature on the first and last surfaces of said negative lens component, the reference symbol f n designates focal length of said negative lens component and the reference symbol f denotes focal length of said photographic lens system as a whole.

Claim 3

A photographic lens system for endoscopes according to claim 1 comprising a positive lens component, a negative lens component and a positive lens component, and having the following numerical data: ______________________________________ f = 49.393, NA = -0.0023 β = -0.051, PS = 0.227 ______________________________________ r.sub.1 = ∞ d.sub.1 = 1.00 n.sub.1 = 1.51633 ν.sub.1 = 64.15 r.sub.2 = ∞ d.sub.2 = 7.8 r.sub.3 = 16.863 d.sub.3 = 2.5 n.sub.2 = 1.80610 ν.sub.2 = 40.95 r.sub.4 = 150.104 d.sub.4 = 1.5351 r.sub.5 = -16.237 d.sub.5 = 1.5 n.sub.3 = 1.64769 ν.sub.3 = 33.80 r.sub.6 = 16.237 d.sub.6 = 2.7702 r.sub.7 = -242.654 d.sub.7 = 3.0 n.sub.4 = 1.58913 ν.sub.4 = 60.97 r.sub.8 = -11.942 d.sub.8 = 12.4047 r.sub.9 = ∞ d.sub.9 = 14.0 n.sub.5 = 1.51633 ν.sub.5 = 64.15 r.sub.10 = ∞ ______________________________________ ##STR7## ##STR8## wherein the reference symbols r.sub.1 through r.sub.10 represent radii of curvature on the surfaces of the respective lens elements including the cover glass and prism, the reference symbols d.sub.1 through d.sub.9 designate thicknesses of the respective lens elements including the cover glass and prism, and airspaces reserved therebetween, the reference symbols n.sub.1 through n.sub.5 denote refractive indices of the respective lens elements including the cover glass and prism, the reference symbols ν.sub.1 through ν.sub.5 represent Abbe's numbers of the respective lens elements including the cover glass and prism the reference symbol f denotes a focal length of the photographic lens system as a whole; the reference symbol NA represents a numerical aperture of the photographic lens system; the reference symbol β denotes a magnification of the photographic lens system; and the reference symbol PS represents Petzval's sum of the photographic lens system.

Claim 4

A photographic lens system for endoscopes according to claim 1 comprising a positive lens component, a negative cemented doublet and a positive lens component, and having the following numerical data: ______________________________________ f = 45.308, NA = -0.0023 β = -0.046, PS = 0.164 ______________________________________ r.sub.1 = ∞ d.sub.1 = 1.0 n.sub.1 = 1.51633 ν.sub.1 = 64.15 r.sub.2 = ∞ d.sub.2 = 7.8 r.sub.3 = 22.5328 d.sub.3 = 2.5 n.sub.2 = 1.80610 ν.sub.2 = 40.95 r.sub.4 = 223.065 d.sub.4 = 1.5351 r.sub.5 = -14.3327 d.sub.5 = 0.7 n.sub.3 = 1.64769 ν.sub.3 = 33.80 r.sub.6 = 50.1736 d.sub.6 = 0.8 n.sub.4 = 1.60729 ν.sub.4 = 49.19 r.sub.7 = 13.7584 d.sub.7 = 2.7702 r.sub.8 = 39.213 d.sub.8 = 3.0 n.sub.5 = 1.58913 ν .sub.5 = 60.97 r.sub.9 = -11.7492 d.sub.9 = 12.4047 r.sub.10 = ∞ d.sub.10 = 14.0 n.sub.6 = 1.51633 ν.sub.6 = 64.15 r.sub.11 = ∞ ______________________________________ ##STR9## ##STR10## wherein the reference symbols r.sub.1 through r.sub.11 represent radii of curvature on the surfaces of the respective lens elements including the cover glass and prism, the reference symbols d.sub.1 through d.sub.10 designate thicknesses of the respective lens elements including the cover glass and prism, and airspaces reserved therebetween, the reference symbols n.sub.1 through n.sub.6 denote refractive indices of the respective lens elements including the cover glass and prism, the reference symbols ν.sub.1 through ν.sub.5 represent Abbe's numbers of the respective lens elements including the cover glass and prism the reference symbol f denotes a focal length of the photographic lens system as a whole; the reference symbol NA represents a numerical aperture of the photographic lens system; the reference symbol β denotes a magnification of the photographic lens system; and the reference symbol PS represents Petzval's sum of the photographic lens system.

Claim 5

A photographic lens system for endoscopes according to claim 1 comprising a positive lens component, a negative lens component and a positive lens component, photographic lens system having the following numerical data: ______________________________________ f = 48.283, NA = -0.0026 β = -0.050, PS = 0.222 ______________________________________ r.sub.1 = ∞ d.sub.1 = 1.00 n.sub.1 - 1.51633 ν.sub.1 = 64.15 r.sub.2 = ∞ d.sub.2 = 4.4451 r.sub.3 = 17.8279 d.sub.3 = 2.5 n.sub.2 = 1.8061 ν.sub.2 = 40.95 r.sub.4 = 152.9169 d.sub.4 = 2.5351 r.sub.5 = -16.0188 d.sub.5 = 1.5 n.sub.3 = 1.64769 ν.sub.3 = 33.80 r.sub.6 = 16.2539 d.sub.6 = 2.7702 r.sub.7 = ∞ d.sub.7 = 3 n.sub.4 = 1.58913 ν.sub.4 = 60.97 r.sub.8 = -11.8785 d.sub.8 = 12.4047 r.sub.9 = ∞ d.sub.1 = 14.0 n.sub.5 = 1.51633 ν.sub.5 = 64.15 r.sub.10 = ∞ ______________________________________ ##STR11## ##STR12## wherein the reference symbols r.sub.1 through r.sub.10 represent radii of curvature on the surfaces of the respective lens elements including the cover glass and prism, the reference symbols d.sub.1 through d.sub.9 designate thicknesses of the respective lens elements including the cover glass and prism, and airspaces reserved therebetween, the reference symbols n.sub.1 through n.sub.5 denote refractive indices of the respective lens elements including the cover glass and prism, the reference symbols ν.sub.1 through ν.sub.5 represent Abbe's numbers of the respective lens elements including the cover glass and prism the reference symbol f denotes a focal length of the photographic lens system as a whole; the reference symbol NA represents a numerical aperture of the photographic lens system; the reference symbol β denotes a magnification of the photographic lens system; and the reference symbol PS represents Petzval's sum of the photographic lens system.