Viewfinder optics with zero power doublet

Claim 2

An optical system of a chromatically neutral viewfinder system, the system having: an aperture stop; positive elements spaced forward of said aperture stop; positive elements spaced rearward of said forward elements and said aperture stop, the rearward elements including an eyepiece element; and every one of the elements forwardly and rearwardly of said aperture stop having convex surfaces, no element forwardly or rearwardly of said aperture stop having a concave surface, a hyperchromatic component which includes a chromatic aberration opposite to the chromatic aberration generated by said positive elements, the component being interposed along the optical axis substantially at the position of said aperture stop between said positive forward elements and said positive rearward elements whereby said component chromatically neutralizes the image.

Claim 3

An optical system of a chromatically neutral viewfinder system incorporating a substantially zero power doublet located near the position of an aperture stop in the system, the system having substantially the following specifications: ______________________________________ Dimensions in Inches Lens Radii Thickness Spacing N.sub.D V ______________________________________ L.sub.1 R.sub.1 =*R(1) T.sub.1 =.1200 1.490 57.4 R.sub.2 =.6940 S.sub.1 =1.4220 L.sub.2 R.sub.3 =2.8570 T.sub.2 =.1400 1.518 59.0 R.sub.4 =1.6140 S.sub.2 =.4500 L.sub.3 R.sub.5 =.8320 T.sub.3 =.1700 1.490 57.4 R.sub.6 =*R(2) S.sub.3 =.6773 L.sub.4 R.sub.7 =4.7230 T.sub.4 =.0300 1.720 29.3 R.sub.8 =-0.1898 S.sub.4 =0 L.sub.5 R.sub.9 =.1898 T.sub.5 =.1000 1.691 54.8 R.sub.10 =INF S.sub.5 =.4430 L.sub.6 R.sub.11 =*R(3) T.sub.6 =.2000 1.490 57.4 R.sub.12 =.5896 S.sub.6 =1.3840 L.sub.7 R.sub.13 =.7000 T.sub.7 =.1850 1.490 57.4 R.sub.14 =*R(4) ______________________________________ wherein the first column lists the lens elements numerically starting at the ray entrance side of the system, the second column lists the respective radii and vertex radii of the aspheric surfaces *R(1) to *R(4), using the convention that the negative (-) values of the radii indicating surfaces which are concave and the positive (+) values of the radii indicating surfaces which are convex; and the third column lists the thicknesses T 1 to T 7 of the respective elements; the fourth column lists the axial spacings S 1 to S 6 between the respective elements, and the fifth and sixth columns list respectively the refractive index N D and the dispersive index V of the respective elements.

Claim 4

An optical system of a chromatically neutral viewfinder system incorporating a substantially zero power doublet located near the position of an aperture stop in the system, the system having substantially the following specifications: ______________________________________ Dimensions in Inches Lens Radii Thickness Spacing N.sub.D V ______________________________________ L.sub.1 R.sub.1 =*R(1) T.sub.1 =.1200 1.490 57.4 R.sub.2 =.6940 S.sub.1 =1.4220 L.sub.2 R.sub.3 =2.8570 T.sub.2 =.1400 1.518 59.0 R.sub.4 =1.6140 S.sub.2 =.4500 L.sub.3 R.sub.5 =.8320 T.sub.3 =.1700 1.490 57.4 R.sub.6 =*R(2) S.sub.3 =.6773 L.sub.4 R.sub.7 =4.7230 T.sub.4 =.0300 1.720 29.3 R.sub.8 =-0.1898 S.sub.4 =0 L.sub.5 R.sub.9 =.1898 T.sub.5 =.1000 1.691 54.8 R.sub.10 =INF S.sub.5 =.4430 L.sub.6 R.sub.11 =*R(3) T.sub.6 =.2000 1.490 57.4 R.sub.12 =.5896 S.sub.6 =1.3840 L.sub.7 R.sub.13 =.7000 T.sub.7 =.1850 1.490 57.4 R.sub.14 =*R(4) ______________________________________ wherein the first column lists the lens elements numerically starting at the ray entrance side of the system, the second column lists the respective radii and vertex radii of the aspheric surfaces *R(1) to *R(4), using the convention that the negative (-) values of the radii indicating surfaces which are concave and the positive (+) values of the radii indicating surfaces which are convex; and the third column lists the thicknesses T 1 to T 7 of the respective elements; the fourth column lists the axial spacings S 1 to S 6 between the respective elements, and the fifth and sixth columns list respectively the refractive index N D and the dispersive index V of the respective elements.

Claim 5

An optical system of a chromatically neutral viewfinder system incorporating a substantially zero power doublet located near the position of an aperture stop in the system, the system having substantially the following specifications: ______________________________________ Dimensions in Inches Lens Radii Thickness Spacing N.sub.D V ______________________________________ L.sub.1 R.sub.1 =*R(1) T.sub.1 =.1200 1.490 57.4 R.sub.2 =.6940 S.sub.1 =1.4220 L.sub.2 R.sub.3 =2.8570 T.sub.2 =.1400 1.518 59.0 R.sub.4 =1.6140 S.sub.2 =.4500 L.sub.3 R.sub.5 =.8320 T.sub.3 =.1700 1.490 57.4 R.sub.6 =*R(2) S.sub.3 =.6673 L.sub.4 R.sub.7 =*R(3) T.sub.4 =.1100 1.490 57.4 R.sub.8 =.1820 S.sub.4 =.0050 L.sub.5 R.sub.9 =.1820 T.sub.5 =.0300 1.592 30.4 R.sub.10 =-1.2821 S.sub.5 =.4430 L.sub.6 R.sub.11 =*R(4) T.sub.6 =.2000 1.490 57.4 R.sub.12 =.5896 S.sub.6 =1.4840 L.sub.7 R.sub.13 =.7000 T.sub.7 =.1850 1.490 57.4 R.sub.14 =*R(5) ______________________________________ wherein the first column lists the lens elements numerically starting at the ray entrance side of the system, the second column lists the respective radii and vertex radii of the aspheric surfaces *R(1) to *R(5), using the convention that the negative (-) values of the radii indicating surfaces which are concave and the positive (+) values of the radii indicating surfaces which are convex; the third column lists the thicknesses T 1 to T 7 of the respective elements; the fourth column lists the axial spacings S 1 to S 6 between the respective elements, and the fifth and sixth columns lists respectively the refractive index N D and the dispersive index V of the respective elements.

Claim 6

An optical system of a chromatically neutral viewfinder system incorporating a substantially zero power doublet located near the position of an aperture stop in the system, the system having substantially the following specifications: ______________________________________ Dimensions in Inches Lens Radii Thickness Spacing N.sub.D V ______________________________________ L.sub.1 R.sub.1 =*R(1) T.sub.1 =.1200 1.490 57.4 R.sub.2 =.6940 S.sub.1 =1.4220 L.sub.2 R.sub.3 =2.8570 T.sub.2 =.1400 1.518 59.0 R.sub.4 =1.6140 S.sub.2 =.4500 L.sub.3 R.sub.5 =.8320 T.sub.3 =.1700 1.490 57.4 R.sub.6 =*R(2) S.sub.3 =.6673 L.sub.4 R.sub.7 =*R(3) T.sub.4 =.1100 1.490 57.4 R.sub.8 =.1820 S.sub.4 =.0050 L.sub.5 R.sub.9 =.1820 T.sub.5 =.0300 1.592 30.4 R.sub.10 =-1.2821 S.sub.5 =.4430 L.sub.6 R.sub.11 =*R(4) T.sub.6 =.2000 1.490 57.4 R.sub.12 =.5896 S.sub.6 =1.4840 L.sub.7 R.sub.13 =.7000 T.sub.7 =.1850 1.490 57.4 R.sub.14 =*R(5) ______________________________________ wherein the first column lists the lens elements numerically starting at the ray entrance side of the system, the second column lists the respective radii and vertex radii of the aspheric surfaces *R(1) to *R(5), using the convention that the negative (-) values of the radii indicating surfaces which are concave and the positive (+) values of the radii indicating surfaces which are convex; the third column lists the thicknesses T 1 to T 7 of the respective elements; the fourth column lists the axial spacings S 1 to S 6 between the respective elements, and the fifth and sixth columns lists respectively the refractive index N D and the dispersive index V of the respective elements.

Claim 7

An optical system of a chromatically neutral viewfinder system incorporating a substantially zero power doublet located near the position of an aperture stop in the system, the system having substantially the following specifications: ______________________________________ Dimensions in Inches Lens Radii Thickness Spacing N.sub.D V ______________________________________ L.sub.1 R.sub.1 =*R(1) T.sub.1 =.1200 1.490 57.4 R.sub.2 =*R(2) S.sub.1 =1.4020 L.sub.2 R.sub.3 =*R(3) T.sub.2 =.1200 1.490 57.4 R.sub.4 =*R(4) S.sub.2 =.7520 L.sub.3 R.sub.5 =5.0000 T.sub.3 =.0300 1.592 30.4 R.sub.6 =-.1763 S.sub.3 =0 L.sub.4 R.sub.7 =.1763 T.sub.4 =.1000 1.490 57.4 R.sub.8 =*R(5) S.sub.4 =.7500 L.sub.5 R.sub.9 =*R(6) T.sub.5 =.1100 1.490 57.4 R.sub.10 =*R(7) S.sub.5 =1.6555 L.sub.6 R.sub.11 =*R(8) T.sub.6 =.1100 1.490 57.4 R.sub.12 =*R(9) ______________________________________ wherein the first column lists the lens elements numerically starting at the ray entrance side of the system, the second column lists the respective radii and vertex radii of the aspheric surfaces *R(1) to *R(9), using the convention that the negative (-) values of the radii indicating surfaces which are concave and the positive (+) values of the radii indicating surfaces which are convex; the third column lists the thicknesses T 1 to T 6 of the respective elements; the fourth column lists the axial spacings S 1 to S 5 between the respective elements, and the fifth and sixth columns list respectively the refractive index N D and the dispersive index V of the respective elements.

Claim 8

An optical system of a chromatically neutral viewfinder system incorporating a substantially zero power doublet located near the position of an aperture stop in the system, the system having substantially the following specifications: ______________________________________ Dimensions in Inches Lens Radii Thickness Spacing N.sub.D V ______________________________________ L.sub.1 R.sub.1 =*R(1) T.sub.1 =.1200 1.490 57.4 R.sub.2 =*R(2) S.sub.1 =1.4020 L.sub.2 R.sub.3 =*R(3) T.sub.2 =.1200 1.490 57.4 R.sub.4 =*R(4) S.sub.2 =.7520 L.sub.3 R.sub.5 =5.0000 T.sub.3 =.0300 1.592 30.4 R.sub.6 =-.1763 S.sub.3 =0 L.sub.4 R.sub.7 =.1763 T.sub.4 =.1000 1.490 57.4 R.sub.8 =*R(5) S.sub.4 =.7500 L.sub.5 R.sub.9 =*R(6) T.sub.5 =.1100 1.490 57.4 R.sub.10 =*R(7) S.sub.5 =1.6555 L.sub.6 R.sub.11 =*R(8) T.sub.6 =.1100 1.490 57.4 R.sub.12 =*R(9) ______________________________________ wherein the first column lists the lens elements numerically starting at the ray entrance side of the system, the second column lists the respective radii and vertex radii of the aspheric surfaces *R(1) to *R(9), using the convention that the negative (-) values of the radii indicating surfaces which are concave and the positive (+) values of the radii indicating surfaces which are convex; the third column lists the thicknesses T 1 to T 6 of the respective elements; the fourth column lists the axial spacings S 1 to S 5 between the respective elements, and the fifth and sixth columns list respectively the refractive index N D and the dispersive index V of the respective elements.

Claim 9

An optical system of a chromatically neutral viewfinder system incorporating a substantially zero power doublet located near the position of an aperture stop in the system, the system having substantially the following specifications: ______________________________________ Dimensions in Inches Lens Radii Thickness Spacing N.sub.D V ______________________________________ L.sub.1 R.sub.1 =*R(1) T.sub.1 =.1200 1.490 57.4 R.sub.2 =*R(2) S.sub.1 =1.4020 L.sub.2 R.sub.3 =*R(3) T.sub.2 =.1200 1.490 57.4 R.sub.4 =*R(4) S.sub.2 =.7520 L.sub.3 R.sub.5 =4.7230 T.sub.3 =.0300 1.720 29.3 R.sub.6 =-.1898 S.sub.3 =0 L.sub.4 R.sub.7 =.1898 T.sub.4 =.1000 1.691 54.8 R.sub.8 =INF S.sub.4 =.7500 L.sub.5 R.sub.9 =*R(5) T.sub.5 =.1100 1.490 57.4 R.sub.10 =*R(6) S.sub.5 =1.6555 L.sub.6 R.sub.11 =*R(7) T.sub.6 =.1100 1.490 57.4 R.sub.12 =*R(8) ______________________________________ wherein the first column lists the lens elements numerically starting at the ray entrance side of the system, the second column lists the respective radii and vertex radii of the aspheric surfaces *R(1) to *R(8), using the convention that the negative (-) values of the radii indicating surfaces which are concave and the positive (+) values of the radii indicating surfaces which are convex; the third column lists the thicknesses T 1 to T 6 of the respective elements; the fourth column lists the axial spacings S 1 to S 5 between the respective elements, and the fifth and sixth columns list respectively the refractive index N D and the dispersive index V of the respective elements.

Claim 10

An optical system of a chromatically neutral viewfinder system incorporating a substantially zero power doublet located near the position of an aperture stop in the system, the system having substantially the following specifications: ______________________________________ Dimensions in Inches Lens Radii Thickness Spacing N.sub.D V ______________________________________ L.sub.1 R.sub.1 =*R(1) T.sub.1 =.1200 1.490 57.4 R.sub.2 =*R(2) S.sub.1 =1.4020 L.sub.2 R.sub.3 =*R(3) T.sub.2 =.1200 1.490 57.4 R.sub.4 =*R(4) S.sub.2 =.7520 L.sub.3 R.sub.5 =4.7230 T.sub.3 =.0300 1.720 29.3 R.sub.6 =-.1898 S.sub.3 =0 L.sub.4 R.sub.7 =.1898 T.sub.4 =.1000 1.691 54.8 R.sub.8 =INF S.sub.4 =.7500 L.sub.5 R.sub.9 =*R(5) T.sub.5 =.1100 1.490 57.4 R.sub.10 =*R(6) S.sub.5 =1.6555 L.sub.6 R.sub.11 =*R(7) T.sub.6 =.1100 1.490 57.4 R.sub.12 =*R(8) ______________________________________ wherein the first column lists the lens elements numerically starting at the ray entrance side of the system, the second column lists the respective radii and vertex radii of the aspheric surfaces *R(1) to *R(8), using the convention that the negative (-) values of the radii indicating surfaces which are concave and the positive (+) values of the radii indicating surfaces which are convex; the third column lists the thicknesses T 1 to T 6 of the respective elements; the fourth column lists the axial spacings S 1 to S 5 between the respective elements, and the fifth and sixth columns list respectively the refractive index N D and the dispersive index V of the respective elements.

Claim 11

An optical system of a chromatically neutral viewfinder system incorporating a substantially zero power doublet located near the position of an aperture stop in the system, the system having substantially the following specifications: ______________________________________ Dimensions in Inches Lens Radii Thickness Spacing N.sub.D V ______________________________________ L.sub.1 R.sub.1 =*R(1) T.sub.1 =.1200 1.490 57.4 R.sub.2 =*R(2) S.sub.1 =1.4020 L.sub.2 R.sub.3 =*R(3) T.sub.2 =.1200 1.490 57.4 R.sub.4 =*R(4) S.sub.2 =.7520 L.sub.3 R.sub.5 =5.0000 T.sub.3 =.0300 1.592 30.4 R.sub.6 =0.1763 S.sub.3 =.0050 L.sub.4 R.sub.7 =.1763 T.sub.4 =.1000 1.490 57.4 R.sub.8 =*R(5) S.sub.4 =.7500 L.sub.5 R.sub.9 =*R(6) T.sub.5 =.1100 1.490 57.4 R.sub.10 =*R(7) S.sub.5 =1.6555 L.sub.6 R.sub.11 =*R(8) T.sub.6 =.1100 1.490 57.4 R.sub.12 =*R(9) ______________________________________ wherein the first column lists the lens elements numerically starting at the ray entrance side of the system, the second column lists the respective radii and vertex radii of the aspheric surfaces *R(1) to *R(9), using the convention that the negative (-) values of the radii indicating surfaces which are concave and the positive (+) values of the radii indicating surfaces which are convex; the third column lists the thicknesses T 1 to T 6 of the respective elements; the fourth column lists the axial spacings S 1 to S 5 between the respective elements, and the fifth and sixth columns list respectively the refractive index N D and the dispersive index V of the respective elements.

Claim 12

An optical system of a chromatically neutral viewfinder system incorporating a substantially zero power doublet located near the position of an aperture stop in the system, the system having substantially the following specifications: ______________________________________ Dimensions in Inches Lens Radii Thickness Spacing N.sub.D V ______________________________________ L.sub.1 R.sub.1 =*R(1) T.sub.1 =.1200 1.490 57.4 R.sub.2 =*R(2) S.sub.1 =1.4020 L.sub.2 R.sub.3 =*R(3) T.sub.2 =.1200 1.490 57.4 R.sub.4 =*R(4) S.sub.2 =.7520 L.sub.3 R.sub.5 =5.0000 T.sub.3 =.0300 1.592 30.4 R.sub.6 =0.1763 S.sub.3 =.0050 L.sub.4 R.sub.7 =.1763 T.sub.4 =.1000 1.490 57.4 R.sub.8 =*R(5) S.sub.4 =.7500 L.sub.5 R.sub.9 =*R(6) T.sub.5 =.1100 1.490 57.4 R.sub.10 =*R(7) S.sub.5 =1.6555 L.sub.6 R.sub.11 =*R(8) T.sub.6 =.1100 1.490 57.4 R.sub.12 =*R(9) ______________________________________ wherein the first column lists the lens elements numerically starting at the ray entrance side of the system, the second column lists the respective radii and vertex radii of the aspheric surfaces *R(1) to *R(9), using the convention that the negative (-) values of the radii indicating surfaces which are concave and the positive (+) values of the radii indicating surfaces which are convex; the third column lists the thicknesses T 1 to T 6 of the respective elements; the fourth column lists the axial spacings S 1 to S 5 between the respective elements, and the fifth and sixth columns list respectively the refractive index N D and the dispersive index V of the respective elements.