Zone focusing optical system

Claim 2

An optical system for a photographic camera, said optical system consisting essentially of: an aperture stop having a predetermined diameter; a first positive meniscus lens element having an aspheric rear surface, said first meniscus lens element having a larger diameter than that of said aperture stop and spaced forwardly thereof; a second meniscus lens element having an aspheric front surface, said second meniscus lens element having a diameter substantially equal to that of said aperture stop and being located proximate said aperture stop whereby said optical system is nonsymmetric about said aperture stop, said aspheric surface of said first meniscus lens element being structured to favorably correct said optical system for off-axis aberrations and said aspheric surface of said second meniscus lens element being structured to favorably correct said optical system for residual spherical aberrations.

Claim 3

The optical system of claim 1 wherein said first meniscus lens element is spaced forward of said aperture stop by a distance substantially equal to said diameter of said aperture stop.

Claim 4

The optical system of claim 2 wherein the diameter of said aperture stop is 0.372 inch and wherein said first meniscus lens element is spaced forwardly thereof by 0.369 inch.

Claim 5

A zone focusing optical system for a photographic camera, said optical system consisting essentially of: an aperture stop having a predetermined diameter; a prime positive meniscus lens element having an aspheric rear surface, said prime meniscus lens element having a diameter larger than that of said aperture stop and spaced forwardly thereof; and a rotationally mounted lens disk including a plurality of angularly spaced apart meniscus lens elements which are selectively alignable in registration with and proximate said aperture stop and each of which has a diameter substantially equal to that of said aperture stop whereby said optical system is nonsymmetric with respect to said aperture stop, said lens disk meniscus lenses each being structured to operate in combination with said prime lens to provide said system with a plurality of effective focal lengths, different from one another, for focusing at different photographic subject distances, said aspheric rear surface of said prime meniscus lens element being structured to favorably correct said optical system for off-axis aberrations and each of said lens disk meniscus lenses including as aspheric front surface structured primarily to favorably correct residual spherical aberrations of said optical system for all positions of said lens disk.

Claim 6

A zone focusing optical system for a photographic camera, said optical system consisting essentially of: an aperture stop having a predetermined diameter; a prime positive meniscus lens element having an aspheric rear surface, said prime meniscus lens element having a diameter larger than that of said aperture stop and spaced forwardly thereof; and a rotationally mounted lens disk including a plurality of angularly spaced apart meniscus lens elements which are selectively alignable in registration with and proximate said aperture stop and each of which has a diameter substantially equal to that of said aperture stop whereby said optical system is nonsymmetric with respect to said aperture stop, said lens disk meniscus lenses each being structured to operate in combination with said prime lens to provide said system with a plurality of effective focal lengths, different from one another, for focusing at different photographic subject distances, said aspheric rear surface of said prime meniscus lens element being structured to favorably correct said optical system for off-axis aberrations and each of said lens disk meniscus lenses including as aspheric front surface structured primarily to favorably correct residual spherical aberrations of said optical system for all positions of said lens disk.

Claim 7

A zone focusing optical system for a photographic camera comprising: a prime positive meniscus lens element having an effective focal length of 4.144 inches and including at least one aspheric surface structured primarily to favorably correct said prime lens element for off-axis aberrations; an aperture stop spaced behind said prime lens element by a predetermined distance; and a rotationally mounted lens disk including four angularly spaced apart meniscus lens elements which are selectively alignable in registration with and proximate said aperture stop, said lens disk meniscus lenses each being structured to operate in combination with said prime lens to provide said system with a plurality of effective focal lengths, different from one another, for focusing at different photographic subject distances and each of said lens disk meniscus lenses including at least one aspheric surface structured primarily to favorably correct residual spherical aberrations of said prime positive meniscus lens element, said lens disk meniscus lens elements having effective focal lengths of 29.974 inches, 128.71 inches, -413.9 inches, and -106.7 inches, respectively.

Claim 8

A zone focusing optical system for a photographic camera comprising: a prime positive meniscus lens element having an effective focal length of 4.144 inches and including at least one aspheric surface structured primarily to favorably correct said prime lens element for off-axis aberrations; an aperture stop spaced behind said prime lens element by a predetermined distance; and a rotationally mounted lens disk including four angularly spaced apart meniscus lens elements which are selectively alignable in registration with and proximate said aperture stop, said lens disk meniscus lenses each being structured to operate in combination with said prime lens to provide said system with a plurality of effective focal lengths, different from one another, for focusing at different photographic subject distances and each of said lens disk meniscus lenses including at least one aspheric surface structured primarily to favorably correct residual spherical aberrations of said prime positive meniscus lens element, said lens disk meniscus lens elements having effective focal lengths of 29.974 inches, 128.71 inches, -413.9 inches, and -106.7 inches, respectively.

Claim 9

A zone focusing optical system for a photographic camera comprising: a prime positive meniscus lens element including at least one aspheric surface structured primarily to favorably correct said prime lens element for off-axis aberrations, said positive meniscus lens element has an index, n d , =1.492; and Abbe number, V, =57.2; front and rear surface basic vertex radii of R F =0.775 and R R =1.185 inches, respectively, an axial thickness=0.125 inches and wherein said aspheric surface comprises said rear surface thereof and is described by the following formula: ##EQU5## an aperture stop spaced behind said prime lens element by a predetermined distance; and a rotationally mounted lens disk including four angularly spaced apart meniscus lens elements which are selectively alignable in registration with and proximate said aperture stop, said lens disk meniscus lenses each being structured to operate in combination with said prime lens to provide said system with a plurality of effective focal lengths, different from one another, for focusing at different photographic subject distances and each of said lens disk meniscus lenses including at least one aspheric surface structured primarily to favorably correct residual spherical aberrations of said prime positive meniscus lens element, said lens disk meniscus lenses, I, II, III and IV, respectively, are represented by the following data: ______________________________________ Lens n.sub.d V Radii (in) t (in) S (in) ______________________________________ I 1.592 30.8 R.sub.1 = -2.0 .0562 .4483 R.sub.2 = -1.825 II 1.592 30.8 R.sub.3 = -10.0 .0553 .4402 R.sub.4 = -8.695 III 1.592 30.8 R.sub.5 = -10.0 .0549 .4402 R.sub.6 = -10.506 IV 1.592 30.8 R.sub.7 = -10.0 .0547 .4402 R.sub.8 = -12.016 ______________________________________ wherein n d is the index of refraction, V is the Abbe number, R 1 , R 2 . . . R 8 , represent basic radii of surfaces, t is the axial thickness and S is the axial distance from the rear surface vertex of said positive meniscus lens element to the vertex of a respective element, and wherein the front surface of element I is an aspheric surface described in the formula: ##EQU6## and elements II, III and IV all have aspheric front surfaces described by the formula: Z=-0.05 y.sup.2 -0.151589 y.sup.4 +0.824884 y.sup.6 and Z in all of the foregoing aspheric formulas representing the distance of a point on the aspheric surface measured from a reference plane perpendicular to the system optic axis and through the vertex of a respective optical element and y is the radial distance of the point away from the optic axis.

Claim 10

A zone focusing optical system for a photographic camera comprising: a prime positive meniscus lens element including at least one aspheric surface structured primarily to favorably correct said prime lens element for off-axis aberrations, said positive meniscus lens element has an index, n d , =1.492; and Abbe number, V, =57.2; front and rear surface basic vertex radii of R F =0.775 and R R =1.185 inches, respectively, an axial thickness=0.125 inches and wherein said aspheric surface comprises said rear surface thereof and is described by the following formula: ##EQU5## an aperture stop spaced behind said prime lens element by a predetermined distance; and a rotationally mounted lens disk including four angularly spaced apart meniscus lens elements which are selectively alignable in registration with and proximate said aperture stop, said lens disk meniscus lenses each being structured to operate in combination with said prime lens to provide said system with a plurality of effective focal lengths, different from one another, for focusing at different photographic subject distances and each of said lens disk meniscus lenses including at least one aspheric surface structured primarily to favorably correct residual spherical aberrations of said prime positive meniscus lens element, said lens disk meniscus lenses, I, II, III and IV, respectively, are represented by the following data: ______________________________________ Lens n.sub.d V Radii (in) t (in) S (in) ______________________________________ I 1.592 30.8 R.sub.1 = -2.0 .0562 .4483 R.sub.2 = -1.825 II 1.592 30.8 R.sub.3 = -10.0 .0553 .4402 R.sub.4 = -8.695 III 1.592 30.8 R.sub.5 = -10.0 .0549 .4402 R.sub.6 = -10.506 IV 1.592 30.8 R.sub.7 = -10.0 .0547 .4402 R.sub.8 = -12.016 ______________________________________ wherein n d is the index of refraction, V is the Abbe number, R 1 , R 2 . . . R 8 , represent basic radii of surfaces, t is the axial thickness and S is the axial distance from the rear surface vertex of said positive meniscus lens element to the vertex of a respective element, and wherein the front surface of element I is an aspheric surface described in the formula: ##EQU6## and elements II, III and IV all have aspheric front surfaces described by the formula: Z=-0.05 y.sup.2 -0.151589 y.sup.4 +0.824884 y.sup.6 and Z in all of the foregoing aspheric formulas representing the distance of a point on the aspheric surface measured from a reference plane perpendicular to the system optic axis and through the vertex of a respective optical element and y is the radial distance of the point away from the optic axis.

Claim 11

A zone focusing optical system for a photographic camera comprising: a prime positive meniscus lens element including at least one aspheric surface structured primarily to favorably correct said prime lens element for off-axis aberrations; an aperture stop spaced behind said prime lens element by a predetermined distance; and a rotationally mounted lens disk including a plurality of angularly spaced apart meniscus lens elements which are selectively alignable in registration with an proximate said aperture stop, said lens disk meniscus lenses each being structured to operate in combination with said prime lens to provide said system with a plurality of effective focal lengths, different from one another, for focusing at different photographic subject distances and each of said lens disk meniscus lenses including at least one aspheric surface structure primarily to favorably correct residual spherical aberrations of said prime positive meniscus lens element, said optical system having the following constructional data for a unit focal length, F, wherein said positive meniscus lens element has an index, n d , =1.4917; and Abbe number, V, =57.2; front and rear surface basic vertex radii of R F =0.1809 and R R =0.2758 respectively; an axial thickness=0.0291 and wherein said aspheric surface comprises said rear surface thereof and is described by the following formula: ##EQU7## wherein said plurality of said lens disk meniscus lenses are four in number, I, II, III and IV, respectively, and are represented by the following data: ______________________________________ Lens n.sub.d V Radii t S ______________________________________ I 1.5860 29.9 R.sub.1 = -.4655 .0134 .0278 R.sub.2 = -.4155 II 1.5860 29.9 R.sub.3 = -2.3275 .0129 .0259 R.sub.4 = -1.8327 III 1.5860 29.9 R.sub.5 = -2.3275 .0128 .0259 R.sub.6 = -2.2942 IV 1.5860 29.9 R.sub.7 = -2.3275 .0127 .0259 R.sub.8 = -2.6813 ______________________________________ wherein F is normalized with respect to the effective focal length of the combination of said meniscus lens element and said lens disk lens IV, n d is the index of refraction, V, is the Abbe number, R 1 , R 2 . . . R 8 , represent basic radii of surfaces, t is the axial thickness, and S is the axial distance from the rear surface vertex of said positive meniscus lens element to the vertex of a respective lens disk element; and wherein the front surface of element I is an aspheric surface described in the formula: ##EQU8## and elements II, III and IV all have aspheric front surfaces described by the formula: Z=-0.05 y.sup.2 -12.0288 y.sup.4 +1207.69 y.sup.6 and Z in all of the foregoing aspheric formulas representing the distance of a point on the aspheric surface measured from a reference plane perpendicular to the system optic axis and through the vertex of a respective optical element and y is the radial distance of the point away from the optic axis.

Claim 12

A zone focusing optical system for a photographic camera comprising: a prime positive meniscus lens element including at least one aspheric surface structured primarily to favorably correct said prime lens element for off-axis aberrations; an aperture stop spaced behind said prime lens element by a predetermined distance; and a rotationally mounted lens disk including a plurality of angularly spaced apart meniscus lens elements which are selectively alignable in registration with an proximate said aperture stop, said lens disk meniscus lenses each being structured to operate in combination with said prime lens to provide said system with a plurality of effective focal lengths, different from one another, for focusing at different photographic subject distances and each of said lens disk meniscus lenses including at least one aspheric surface structure primarily to favorably correct residual spherical aberrations of said prime positive meniscus lens element, said optical system having the following constructional data for a unit focal length, F, wherein said positive meniscus lens element has an index, n d , =1.4917; and Abbe number, V, =57.2; front and rear surface basic vertex radii of R F =0.1809 and R R =0.2758 respectively; an axial thickness=0.0291 and wherein said aspheric surface comprises said rear surface thereof and is described by the following formula: ##EQU7## wherein said plurality of said lens disk meniscus lenses are four in number, I, II, III and IV, respectively, and are represented by the following data: ______________________________________ Lens n.sub.d V Radii t S ______________________________________ I 1.5860 29.9 R.sub.1 = -.4655 .0134 .0278 R.sub.2 = -.4155 II 1.5860 29.9 R.sub.3 = -2.3275 .0129 .0259 R.sub.4 = -1.8327 III 1.5860 29.9 R.sub.5 = -2.3275 .0128 .0259 R.sub.6 = -2.2942 IV 1.5860 29.9 R.sub.7 = -2.3275 .0127 .0259 R.sub.8 = -2.6813 ______________________________________ wherein F is normalized with respect to the effective focal length of the combination of said meniscus lens element and said lens disk lens IV, n d is the index of refraction, V, is the Abbe number, R 1 , R 2 . . . R 8 , represent basic radii of surfaces, t is the axial thickness, and S is the axial distance from the rear surface vertex of said positive meniscus lens element to the vertex of a respective lens disk element; and wherein the front surface of element I is an aspheric surface described in the formula: ##EQU8## and elements II, III and IV all have aspheric front surfaces described by the formula: Z=-0.05 y.sup.2 -12.0288 y.sup.4 +1207.69 y.sup.6 and Z in all of the foregoing aspheric formulas representing the distance of a point on the aspheric surface measured from a reference plane perpendicular to the system optic axis and through the vertex of a respective optical element and y is the radial distance of the point away from the optic axis.

Claim 13

The system of claim 7 wherein the effective focal length of the combination of said meniscus lens element and said lens disk meniscus lens IV is 4.2965 inches.