Graded refractive index single lens system

Claim 2

A graded refractive index single lens system comprising at least one surface formed spherically, having refractive index n expressed by the formula shown below wherein n 0 represents the refractive index on the optical axis of said lens and r represents the radial distance from the optical axis, and satisfying the conditions (1) and (2) shown below: n.sup.2 =n.sub.0.sup.2 [1-(gr).sup.2 +h.sub.4 (gr).sup.4 +h.sub.6 (gr).sup.6 +h.sub.8 (gr).sup.8 +h.sub.10 (gr).sup.10 ] -1.5<1/h.sub.8 <2 (1) -5<h.sub.10 (2) where g is a parameter representing the degree of the gradient of the refractive index distribuiton, and h 4 , h 6 , h 8 and h 10 respectively represent the higher order coefficients of said refractive index distribution.

Claim 3

A graded refractive index single lens system according to claim 1 wherein said graded refractive index single lens system has the following numerical data: ______________________________________ R.sub.1 = 1.148 R.sub.2 = -2.416 D = 1.44 n.sub.0 = 1.65 g = 0.458 h.sub.4 = 0.051 h.sub.6 = 3.715 h.sub.8 = 25.497 h.sub.10 = 303.03 f = 1.0 NA = 0.7 ______________________________________ where R 1 and R 2 respectively represent the radii of curvatures of said lens surfaces at the long conjugate side and at the short conjugate side, D represents the length of the lens, f represents the focal length of said lens, and NA represents the numerical aperture at the short conjugate side of said lens.

Claim 4

A graded refractive index single lens system according to claim 1 wherein said graded refractive index single lens system has the following numerical data: ______________________________________ R.sub.1 = 1.474 R.sub.2 = -6.146 D = 1.68 n.sub.0 = 1.65 g = 0.542 h.sub.4 = -0.401 h.sub.6 = 0.064 h.sub.8 = 0.725 h.sub.10 = 0.199 × f = 1.0 NA = 0.7 10.sup.-2 ______________________________________ where R 1 and R 2 respectively represent the radii of curvatures of said lens surfaces at the long conjugate side and at the short conjugate side, D represents the length of the lens, f represents the focal length of said lens, and NA represents the numerical aperture at the short conjugate side of said lens.

Claim 5

A graded refractive index single lens system according to claim 1 wherein said graded refractive index single lens system has the following numerical data: ______________________________________ R.sub.1 = 0.920 R.sub.2 = -2.773 D = 1.20 n.sub.0 = 1.65 g = 0.375 h.sub.4 = 4.199 h.sub.6 = 48.472 h.sub.8 = 552.27 h.sub.10 = 9904.7 f = 1.0 NA = 0.6 ______________________________________ where R 1 and R 2 respectively represent the radii of curvatures of said lens surfaces at the long conjugate side and at the short conjugate side, D represents the length of the lens, f represents the focal length of said lens, and NA represents the numerical aperture at the short conjugate side of said lens.

Claim 6

A graded refractive index single lens system according to claim 1 wherein said graded refractive index single lens system has the following numerical data: ______________________________________ R.sub.1 = 1.590 R.sub.2 = -1.332 D = 1.56 n.sub.0 = 1.65 g = 0.458 h.sub.4 = 1.264 h.sub.6 = 6.116 h.sub.8 = 115.36 h.sub.10 = 0.164 f = 1.0 NA = 0.6 ______________________________________ where R 1 and R 2 respectively represent the radii of curvatures of said lens surfaces at the long conjugate side and at the short conjugate side, D represents the length of the lens, f represents the focal length of said lens, and NA represents the numerical aperture at the short conjugate side of said lens.

Claim 7

A graded refractive index single lens system according to claim 1 wherein said graded refractive index single lens system has the following numerical data: ______________________________________ R.sub.1 = 0.917 R.sub.2 = 8.330 D = 1.08 n.sub.0 = 1.65 g = 0.500 h.sub.4 = -0.543 h.sub.6 = 0.528 h.sub.8 = 9.230 h.sub.10 = 0.015 f = 1.0 NA = 0.6 ______________________________________ where R 1 and R 2 respectively represent the radii of curvatures of said lens surfaces at the long conjugate side and at the short conjugate side, D represents the length of the lens, f represents the focal length of said lens, and NA represents the numerical aperture at the short conjugate side of said lens.

Claim 8

A graded refractive index single lens system according to claim 1 wherein said graded refractive index single lens system has the following numerical data: ______________________________________ R.sub.1 = 1.191 R.sub.2 = 1.963 D = 1.44 n.sub.0 = 1.65 g = 0.583 h.sub.4 = -0.742 h.sub.6 = -1.004 h.sub.8 = -1.465 h.sub.10 = -0.341 × f = 1.0 NA = 0.6 10.sup.-2 ______________________________________ where R 1 and R 2 respectively represent the radii of curvatures of said lens surfaces at the long conjugate side and at the short conjugate side, D represents the length of the lens, f represents the focal length of said lens, and NA represents the numerical aperture at the short conjugate side of said lens.

Claim 9

A graded refractive index single lens system according to claim 1 wherein said graded refractive index single lens system has the following numerical data: ______________________________________ R.sub.1 = 0.952 R.sub.2 = -1.343 D = 1.20 n.sub.0 = 1.65 g = 0.250 h.sub.4 = 53.307 h.sub.6 = 1328.3 h.sub.8 = 52358 h.sub.10 = 14.754 f = 1.0 NA = 0.5 ______________________________________ where R 1 and R 2 respectively represent the radii of curvatures of said lens surfaces at the long conjugate side and at the short conjugate side, D represents the length of the lens, f represents the focal length of said lens, and NA represents the numerical aperture at the short conjugate side of said lens.

Claim 10

A graded refractive index single lens system according to claim 1 wherein said graded refractive index single lens system has the following numerical data: ______________________________________ R.sub.1 = 0.831 R.sub.2 = -26.298 D = 0.96 n.sub.0 = 1.65 g = 0.417 h.sub.4 = 2.374 h.sub.6 = 28.892 h.sub.8 = 460.17 h.sub.10 = 0.384 f = 1.0 NA = 0.5 ______________________________________ where R 1 and R 2 respectively represent the radii of curvatures of said lens surfaces at the long conjugate side and at the short conjugate side, D represents the length of the lens, f represents the focal length of said lens, and NA represents the numerical aperture at the short conjugate side of said lens.

Claim 11

A graded refractive index single lens system according to claim 1 wherein said graded refractive index single lens system has the following numerical data: ______________________________________ R.sub.1 = 2.876 R.sub.2 = -1.241 D = 1.80 n.sub.0 = 1.65 g = 0.500 h.sub.4 = 1.232 h.sub.6 = 4.005 h.sub.8 = 15.651 h.sub.10 = 0.017 f = 1.0 NA = 0.5 ______________________________________ where R 1 and R 2 respectively represent the radii of curvatures of said lens surfaces at the long conjugate side and at the short conjugate side, D represents the length of the lens, f represents the focal length of said lens, and NA represents the numerical aperture at the short conjugate side of said lens.

Claim 12

A graded refractive index single lens system according to claim 1 wherein said graded refractive index single lens system has the following numerical data: ______________________________________ R.sub.1 = 0.741 R.sub.2 = 15.040 D = 0.36 n.sub.0 = 1.65 g = 0.542 h.sub.4 = -0.677 h.sub.6 = -0.814 h.sub.8 = -57.893 h.sub.10 = -0.086 f = 1.0 NA = 0.5 ______________________________________ wherein R 1 and R 2 respectively represent the radii of curvatures of said lens surfaces at the long conjugate side and at the short conjugate side, D represents the length of the lens, f represents the focal length of said lens, and NA represents the numerical aperture at the short conjugate side of said lens.

Claim 13

A graded refractive index single lens system according to claim 1 wherein said graded refractive index single lens system has the following numerical data: ______________________________________ R.sub.1 = 1.138 R.sub.2 = 1.216 D = 1.32 n.sub.0 = 1.65 g = 0.625 h.sub.4 = -0.753 h.sub.6 = -1.412 h.sub.8 = 2.649 h.sub.10 = 0.066 f = 1.0 NA = 0.5 ______________________________________ where R 1 and R 2 respectively represent the radii of curvatures of said lens surfaces at the long conjugate side and at the short conjugate side, D represents the length of the lens, f represents the focal length of said lens, and NA represents the numerical aperture at the short conjugate side of said lens.

Claim 14

A graded refractive index single lens system according to claim 1 wherein said graded refractive index single lens system has the following numerical data: ______________________________________ R.sub.1 = 0.923 R.sub.2 = 2.032 D = 0.72 n.sub.0 = 1.65 g = 0.708 h.sub.4 = -0.970 h.sub.6 = -1.778 h.sub.8 = -3.194 h.sub.10 = -0.764 × f = 1.0 NA = 0.5 10.sup.-2 ______________________________________ where R 1 and R 2 respectively represent the radii of curvatures of said lens surfaces at the long conjugate side and at the short conjugate side, D represents the length of the lens, f represents the focal length of said lens, and NA represents the numerical aperture at the short conjugate side of said lens.

Claim 15

A graded refractive index single lens system according to claim 1 wherein said graded refractive index single lens system has the following numerical data: ______________________________________ R.sub.1 = 0.957 R.sub.2 = 1.710 D = 0.72 n.sub.0 = 1.65 g = 0.750 h.sub.4 = -0.842 h.sub.6 = -1.280 h.sub.8 = -1.308 h.sub.10 = -0.319 × f = 1.0 NA = 0.5 10.sup.-2 ______________________________________ where R 1 and R 2 respectively represent the radii of curvatures of said lens surfaces at the long conjugate side and at the short conjugate side, D represents the length of the lens, f represents the focal length of said lens, and NA represents the numerical aperture at the short conjugate side of said lens.

Claim 16

A graded refractive index single lens system according to claim 1 wherein said graded refractive index single lens system has the following numerical data: ______________________________________ R.sub.1 = 1.753 R.sub.2 = -0.982 D = 1.44 n.sub.0 = 1.65 g = 0.375 h.sub.4 = 8.898 h.sub.6 = 70.914 h.sub.8 = 1868.5 h.sub.10 = -2.900 f = 1.0 NA = 0.5 ______________________________________ where R 1 and R 2 respectively represent the radii of curvatures of said lens surfaces at the long conjugate side and at short conjugate side, D represents the length of the lens, f represents the focal length of said lens, and NA represents the numerical aperture at the short conjugate side of said lens.