Optical viewing system

Claim 2

An optical system arranged along an optical axis, said optical system comprising, from object to image space: a first lens group consisting of at least one element of negative power including at least one aspheric surface; a second lens group consisting of at least one element of positive power, the powers of said first and second groups, and the spacing therebetween being such that said groups in combination are convergent, forming a real image in a predetermined plane located behind said second group; a third lens group consisting of at least one element of positive power; and a fourth lens group consisting of at least one element of positive power, the powers of said third and fourth groups and the spacing therebetween being such that said third and fourth groups form a substantially collimated image of said real image formed by said first and second groups.

Claim 3

The optical system of claim 1 wherein said element of said first lens group is a meniscus of convexo-concave form.

Claim 4

An optical system arranged along an optical axis, said optical system comprising, from object to image space: a first lens group consisting of at least one element of negative power; a second lens group consisting of at least one element of positive power, the powers of said first and second groups, and the spacing therebetween being such that said groups in combination are convergent, forming a real image in a predetermined plane located behind said second group; a third lens group consisting of at least one element of positive power; and a fourth lens group consisting of at least one element of positive power, the powers of said third and fourth groups and the spacing therebetween being such that said third and fourth groups form a substantially collimated image of said real image formed by said first and second groups, said optical system's optical path being folded four times.

Claim 5

An optical system arranged along an optical axis, said optical system comprising, from object to image space: a first lens group consisting of at least one element of negative power; a second lens group consisting of at least one element of positive power, the powers of said first and second groups, and the spacing therebetween being such that said groups in combination are convergent, forming a real image in a predetermined plane located behind said second group; a third lens group consisting of at least one element of positive power; and a fourth lens group consisting of at least one element of positive power, the powers of said third and fourth groups and the spacing therebetween being such that said third and fourth groups form a substantially collimated image of said real image formed by said first and second groups, said optical system's optical path being folded four times.

Claim 6

The system of claim 3 wherein said optical system further includes four plano mirrors, one each for each of said folds in said optical path.

Claim 7

The optical system of claim 4 wherein said mirrors are arranged with respect to said lens groups to fold said optical path, when viewed from image space, first up, then to the left, then down, and finally rearwardly and downwardly so that the final leg of said optical path is offset and skewed with respect to its initial leg.

Claim 8

The optical system of claim 5 wherein said fourth lens group further includes a prism to compensate for the skew in said final leg of said optical path.

Claim 9

The optical system of claim 4 wherein said four mirrors are arranged around said second lens group.

Claim 10

A multi-element optical system arranged along an optical axis and having constructional data substantially as follows: ______________________________________ Ele- Sur- Separation ment face Radius Medium Air N.sub.d V.sub.d ______________________________________ I 1 3.5959 .0854 1.4917 59.2 2* .5463 .2136 II 3 1.2433 .0854 1.4917 59.2 4* .7212 2.0962 III 5* -3.2708 .0854 1.4917 59.2 6 -2.1673 .0142 IV 7 -891.8444 .0854 1.4917 59.2 8 -.9827 4.3788 V 9 plano .2534 1.4917 59.2 10* -2.079 1.237 VI 11* 1.6637 .3080 1.4917 59.2 12 -4.5623 ______________________________________ *aspheric in which said surfaces are numbered in their order from object to image space, said radii and separations are normalized with respect to the combined focal length, f o , of said first through said fourth element, N d is the index of refraction, V d is the Abbe dispersion number and wherein surfaces 2, 4, 5, 10 and 11 are aspheric in shape and have the general formula: ##EQU3## where C is the reciprocal of the surface apex radius, Z represents the distance of a point on the aspheric surface measured from the surface vertex and parallel to the Z-axis, S is the radial distance of the point measured perpendicular to the Z-axis and wherein the coefficients, β through ε, and the conic constant K, normalized to fo are: ______________________________________ Surface 2 4 6 10 11 ______________________________________ K -2.0596 0.0 0.0 0.0 beta 0.0 1.3122 -1.6966 × 0.0 -4.3989 × 10.sup.-1 10.sup.-2 gamma 0.0 0.0 -3.3069 × 0.0 -3.0754 × 10.sup.-2 10.sup.-3 delta 0.0 0.0 0.0 0.0 0.0 epsilon 0.0 0.0 0.0 -9.3215 × 0.0 10.sup.-2 ______________________________________

Claim 11

A multi-element optical system arranged along an optical axis and having constructional data substantially as follows: ______________________________________ Ele- Sur- Separation ment face Radius Medium Air N.sub.d V.sub.d ______________________________________ I 1 3.5959 .0854 1.4917 59.2 2* .5463 .2136 II 3 1.2433 .0854 1.4917 59.2 4* .7212 2.0962 III 5* -3.2708 .0854 1.4917 59.2 6 -2.1673 .0142 IV 7 -891.8444 .0854 1.4917 59.2 8 -.9827 4.3788 V 9 plano .2534 1.4917 59.2 10* -2.079 1.237 VI 11* 1.6637 .3080 1.4917 59.2 12 -4.5623 ______________________________________ *aspheric in which said surfaces are numbered in their order from object to image space, said radii and separations are normalized with respect to the combined focal length, f o , of said first through said fourth element, N d is the index of refraction, V d is the Abbe dispersion number and wherein surfaces 2, 4, 5, 10 and 11 are aspheric in shape and have the general formula: ##EQU3## where C is the reciprocal of the surface apex radius, Z represents the distance of a point on the aspheric surface measured from the surface vertex and parallel to the Z-axis, S is the radial distance of the point measured perpendicular to the Z-axis and wherein the coefficients, β through ε, and the conic constant K, normalized to fo are: ______________________________________ Surface 2 4 6 10 11 ______________________________________ K -2.0596 0.0 0.0 0.0 beta 0.0 1.3122 -1.6966 × 0.0 -4.3989 × 10.sup.-1 10.sup.-2 gamma 0.0 0.0 -3.3069 × 0.0 -3.0754 × 10.sup.-2 10.sup.-3 delta 0.0 0.0 0.0 0.0 0.0 epsilon 0.0 0.0 0.0 -9.3215 × 0.0 10.sup.-2 ______________________________________

Claim 12

A multi-element optical system arranged along an optical axis and having constructional data substantially as follows: ______________________________________ Ele- Sur- Separation ment face Radius Medium Air N.sub.d V.sub.d ______________________________________ I 1 3.2650 .0608 1.4917 59.2 2* 0.4697 .1825 II 3 1.1289 .0608 1.4917 59.2 4* 0.6263 1.7779 III 5* -2.7873 .1216 1.4917 59.2 6 -0.6143 3.8863 IV 7* plano .2311 1.4917 59.2 8 -1.5206 1.6469 V 9 1.2165 .1825 1.4917 59.2 10* -9.1068 ______________________________________ *aspheric in which said surfaces are numbered in their order from object to image space, said radii and separations are normalized with respect to the combined focal length, fo, of said first through said fourth element, N d is the index of refraction, V d is the Abbe dispersion number and wherein surfaces 2, 4, 5, 7 and 10 are aspheric in shape and have the general formula: ##EQU4## where C is the reciprocal of the surface apex radius, Z represents the distance of a point on the aspheric surface measured from the surface vertex and parallel to the Z-axis, S is the radial distance of the point measured perpendicular to the Z-axis and wherein three coefficients, β through ε, and the conic constant K, normalized to fo are: ______________________________________ Surface 2 4 5 7 10 ______________________________________ K -2.3073 0.0 -4.2598 × 0.0 0.0 10.sup.-1 beta 0.0 1.8387 -5.4764 × -3.9491 × 9.0058 × 10.sup.-1 10.sup.-2 10.sup.-2 gamma 0.0 0.0 -1.4393 × 9.7311 × -5.4472 × 10.sup.-1 10.sup.-3 10.sup.-2 delta 0.0 0.0 9.8715 × 0.0 0.0 10.sup.-1 epsilon 0.0 0.0 0.0 0.0 0.0 ______________________________________

Claim 13

A multi-element optical system arranged along an optical axis and having constructional data substantially as follows: ______________________________________ Ele- Sur- Separation ment face Radius Medium Air N.sub.d V.sub.d ______________________________________ I 1 3.2650 .0608 1.4917 59.2 2* 0.4697 .1825 II 3 1.1289 .0608 1.4917 59.2 4* 0.6263 1.7779 III 5* -2.7873 .1216 1.4917 59.2 6 -0.6143 3.8863 IV 7* plano .2311 1.4917 59.2 8 -1.5206 1.6469 V 9 1.2165 .1825 1.4917 59.2 10* -9.1068 ______________________________________ *aspheric in which said surfaces are numbered in their order from object to image space, said radii and separations are normalized with respect to the combined focal length, fo, of said first through said fourth element, N d is the index of refraction, V d is the Abbe dispersion number and wherein surfaces 2, 4, 5, 7 and 10 are aspheric in shape and have the general formula: ##EQU4## where C is the reciprocal of the surface apex radius, Z represents the distance of a point on the aspheric surface measured from the surface vertex and parallel to the Z-axis, S is the radial distance of the point measured perpendicular to the Z-axis and wherein three coefficients, β through ε, and the conic constant K, normalized to fo are: ______________________________________ Surface 2 4 5 7 10 ______________________________________ K -2.3073 0.0 -4.2598 × 0.0 0.0 10.sup.-1 beta 0.0 1.8387 -5.4764 × -3.9491 × 9.0058 × 10.sup.-1 10.sup.-2 10.sup.-2 gamma 0.0 0.0 -1.4393 × 9.7311 × -5.4472 × 10.sup.-1 10.sup.-3 10.sup.-2 delta 0.0 0.0 9.8715 × 0.0 0.0 10.sup.-1 epsilon 0.0 0.0 0.0 0.0 0.0 ______________________________________

Claim 14

An optical system arranged along an optical axis, said optical system comprising, from object to image space: a first lens group consisting of at least one element of negative power; a second lens group consisting of at least one element of positive power including at least one aspheric surface, the powers of said first and second groups, and the spacing therebetween being such that said groups in combination are convergent, forming a real image in a predetermined plane located behind said second group; a third lens group consisting of at least one element of positive power; and a fourth lens group consisting of at least one element of positive power, the powers of said third and fourth groups and the spacing therebetween being such that said third and fourth groups form a substantially collimated image of said real image formed by said first and second groups.

Claim 15

An optical system arranged along an optical axis, said optical system comprising, from object to image space: a first lens group consisting of at least one element of negative power; a second lens group consisting of at least one element of positive power including at least one aspheric surface, the powers of said first and second groups, and the spacing therebetween being such that said groups in combination are convergent, forming a real image in a predetermined plane located behind said second group; a third lens group consisting of at least one element of positive power; and a fourth lens group consisting of at least one element of positive power, the powers of said third and fourth groups and the spacing therebetween being such that said third and fourth groups form a substantially collimated image of said real image formed by said first and second groups.

Claim 16

An optical system arranged along an optical axis, said optical system comprising, from object to image space: a first lens group consisting of at least one element of negative power; a second lens group consisting of at least two elements of positive power, the powers of said first and second groups, and the spacing therebetween being such that said groups in combination are convergent, forming a real image in a predetermined plane located behind said second group; a third lens group consisting of at least one element of positive power; and a fourth lens group consisting of at least one element of positive power, the powers of said third and fourth groups and the spacing therebetween being such that said third and fourth groups form a substantially collimated image of said real image formed by said first and second groups.

Claim 17

An optical system arranged along an optical axis, said optical system comprising, from object to image space: a first lens group consisting of at least one element of negative power; a second lens group consisting of at least two elements of positive power, the powers of said first and second groups, and the spacing therebetween being such that said groups in combination are convergent, forming a real image in a predetermined plane located behind said second group; a third lens group consisting of at least one element of positive power; and a fourth lens group consisting of at least one element of positive power, the powers of said third and fourth groups and the spacing therebetween being such that said third and fourth groups form a substantially collimated image of said real image formed by said first and second groups.

Claim 18

An optical system arranged along an optical axis, said optical system comprising, from object to image space: a first lens group consisting of at least two elements of negative power, both of which are meniscii of convexo-concave form; a second lens group consisting of at least one element of positive power, the powers of said first and second groups, and the spacing therebetween being such that said groups in combination are convergent, forming a real image in a predetermined plane located behind said second group; a third lens group consisting of at least one element of positive power; and a fourth lens group consisting of at least one element of positive power, the powers of said third and fourth groups and the spacing therebetween being such that said third and fourth groups form a substantially collimated image of said real image formed by said first and second groups.

Claim 19

An optical system arranged along an optical axis, said optical system comprising, from object to image space: a first lens group consisting of at least two elements of negative power, both of which are meniscii of convexo-concave form; a second lens group consisting of at least one element of positive power, the powers of said first and second groups, and the spacing therebetween being such that said groups in combination are convergent, forming a real image in a predetermined plane located behind said second group; a third lens group consisting of at least one element of positive power; and a fourth lens group consisting of at least one element of positive power, the powers of said third and fourth groups and the spacing therebetween being such that said third and fourth groups form a substantially collimated image of said real image formed by said first and second groups.

Claim 20

An optical system arranged along an optical axis, said optical system comprising, from object to image space: a first lens group consisting of at least one element of negative power; a second lens group consisting of at least one element of positive power, the powers of said first and second groups, and the spacing therebetween being such that said groups in combination are convergent, forming a real image in a predetermined plane located behind said second group; a third lens group consisting of at least one element of positive power; and a fourth lens group consisting of at least one element of positive power, the powers of said third and fourth groups and the spacing therebetween being such that said third and fourth groups form a substantially collimated image of said real image formed by said first and second groups, one element of each lens group of said optical system having at least one aspheric surface.

Claim 21

An optical system arranged along an optical axis, said optical system comprising, from object to image space: a first lens group consisting of at least one element of negative power; a second lens group consisting of at least one element of positive power, the powers of said first and second groups, and the spacing therebetween being such that said groups in combination are convergent, forming a real image in a predetermined plane located behind said second group; a third lens group consisting of at least one element of positive power; and a fourth lens group consisting of at least one element of positive power, the powers of said third and fourth groups and the spacing therebetween being such that said third and fourth groups form a substantially collimated image of said real image formed by said first and second groups, one element of each lens group of said optical system having at least one aspheric surface.

Claim 22

An optical system arranged along an optical axis, said optical system comprising, from object to image space: a first lens group consisting of at least one element of negative power; a second lens group consisting of at least one element of positive power, the powers of said first and second groups, and the spacing therebetween being such that said groups in combination are convergent, forming a real image in a predetermined plane located behind said second group; a third lens group consisting of at least one element of positive power; and a fourth lens group consisting of at least one element of positive power, the powers of said third and fourth groups and the spacing therebetween being such that said third and fourth groups form a substantially collimated image of said real image formed by said first and second groups, said optical system's aperture stop being between said first and second lens groups.

Claim 23

An optical system arranged along an optical axis, said optical system comprising, from object to image space: a first lens group consisting of at least one element of negative power; a second lens group consisting of at least one element of positive power, the powers of said first and second groups, and the spacing therebetween being such that said groups in combination are convergent, forming a real image in a predetermined plane located behind said second group; a third lens group consisting of at least one element of positive power; and a fourth lens group consisting of at least one element of positive power, the powers of said third and fourth groups and the spacing therebetween being such that said third and fourth groups form a substantially collimated image of said real image formed by said first and second groups, said optical system's aperture stop being between said first and second lens groups.

Claim 24

The optical system of claim 14 wherein said aperture stop is located ahead of said second lens group by a distance which does not exceed one third of the distance separating said first and second lens groups.

Claim 25

An optical system arranged along an optical axis, said optical system comprising, from object to image space: a first lens group consisting of at least two elements of negative power, each of which is aspheric; a second lens group consisting of at least one element of positive power, the powers of said first and second groups, and the spacing therebetween being such that said groups in combination are convergent, forming a real image in a predetermined plane located behind said second group; a third lens group consisting of at least one element of positive power; and a fourth lens group consisting of at least one element of positive power, the powers of said third and fourth groups and the spacing therebetween being such that said third and fourth groups form a substantially collimated image of said real image formed by said first and second groups.

Claim 26

An optical system arranged along an optical axis, said optical system comprising, from object to image space: a first lens group consisting of at least two elements of negative power, each of which is aspheric; a second lens group consisting of at least one element of positive power, the powers of said first and second groups, and the spacing therebetween being such that said groups in combination are convergent, forming a real image in a predetermined plane located behind said second group; a third lens group consisting of at least one element of positive power; and a fourth lens group consisting of at least one element of positive power, the powers of said third and fourth groups and the spacing therebetween being such that said third and fourth groups form a substantially collimated image of said real image formed by said first and second groups.