US5559638A — Wide-angle lens system #6

Claim 1

Independent Claim 122 words

A wide-angle lens system comprising, in order from the object side: a front unit, a stop and a rear unit; wherein said front unit comprises, in order from the object side, a first lens unit which comprises a plurality of lens components including a positive lens component and has a negative refractive power as a whole, a negative lens component which has a concave surface on the object side as well as air-contact surfaces on the object side and the image side, and a cemented lens component, and wherein said rear unit comprises a negative lens component disposed at a location closest to said stop and at least two positive lens components disposed on the image side of said negative lens component.

Claim 2

Dependent Claim 122 words

A wide-angle lens system comprising, in order from the object side: a front unit, a stop and a rear unit; wherein said front unit comprises, in order from the object side, a first lens unit which comprises a plurality of lens components including a positive lens component and has a negative refractive power as a whole, a negative lens component which has a concave surface on the object side as well as air-contact surfaces on the object side and the image side, and a cemented lens component, and wherein said rear unit comprises a negative lens component disposed at a location closest to said stop and at least two positive lens components disposed on the image side of said negative lens component.

Claim 3

Dependent Claim 38 words

A wide-angle lens system according to claim 1 wherein said front unit comprises at least one aspherical surface having a positive refractive power which is strengthened as portions of said aspherical surface are farther from an optical axis.

Claim 4

Dependent Claim 38 words

A wide-angle lens system according to claim 1 wherein said rear unit comprises at least one aspherical surface having a positive refractive power which is weakened as portions of said aspherical surface are farther from an optical axis.

Claim 5

Dependent Claim 40 words

A wide-angle lens system according to claim 1 wherein said lens system is focused on objects located within a range from an infinite distance to a short distance by varying at least one of airspaces reserved in said lens system.

Claim 6

Dependent Claim 42 words

A wide-angle lens system according to claim 4 wherein said lens system is focused on the objects located within the range from the infinite distance to the short distance by varying airspaces reserved in said first lens unit relatively to each other.

Claim 7

Dependent Claim 34 words

A wide-angle lens system according to claim 5 wherein said airspace is narrowed for focusing said lens system from the object located at the infinite distance onto the object located at the short distance.

Claim 8

Dependent Claim 41 words

A wide-angle lens system according to claim 4 wherein said lens system is focused onto the objects located within the range from the infinite distance to the short distance by varying airspaces reserved in said rear unit relatively to each other.

Claim 9

Dependent Claim 42 words

A wide-angle lens system according to claim 1 wherein said lens system is focused onto the objects located within the range from the infinite distance to the short distance by varying an airspace reserved between said first lens unit and said stop.

Claim 10

Dependent Claim 42 words

A wide-angle lens system according to claim 4 wherein said lens system is focused onto the objects located within the range from the infinite distance to the short distance by varying an airspace reserved between said first lens unit and said stop.

Claim 11

Dependent Claim 56 words

A wide-angle lens system according to claim 1, 2, 3, 4, 5, 6, 7, 8 or 9 satisfying the following condition (1): -2.0<f/f.sub.1 <-0.2 (1) wherein the reference symbol f represents a focal length of said lens system as a whole and the reference symbol f 1 designates a focal length of said first lens unit.

Claim 12

Dependent Claim 55 words

A wide-angle lens system according to claim 1, 2, 3, 4, 5, 6, 7, 8 or 9 satisfying the following condition (2): 0.2<f/f.sub.R <1.0 (2) wherein the reference symbol f represents a focal length of said lens system as a whole and the reference symbol f R designates a focal length of said rear unit.

Claim 13

Dependent Claim 97 words

A wide-angle lens system according to claim 1, 2, 3, 4, 5, 6, 7, 8 or 9 satisfying the following condition (3): -1.0<(R.sub.F +R.sub.R)/(R.sub.F -R.sub.R)<0 (3) wherein the reference symbols R F and R R represent radii of curvature on an object side surface and an image side surface respectively of an air lens formed between: an image side surface of the negative lens component which is comprised in the first lens unit and an object side surface of the negative lens component arranged on the object side of the cemented lens component in the front unit.

Claim 14

Dependent Claim 84 words

A wide-angle lens system according to claim 1, 2, 3, 4, 5, 6, 7, 8 or 9 satisfying the following condition (4): 0<(R.sub.FS +R.sub.RS)/(R.sub.FS -R.sub.RS)<1.0 (4) wherein the reference symbol R FS represents a radius of curvature on a surface which is disposed on the object side of said stop and closest to said stop, and the reference symbol R RS designates a radius of curvature on a surface which is disposed on the image side of said stop and closest to said stop.

Claim 15

Dependent Claim 65 words

A wide-angle lens system according to claim 1, 2, 3, 4, 5, 6, 7, 8 or 9 satisfying the following condition (5): 0.1<D.sub.C /f<1.0 (5) wherein the reference symbol f represents a focal length of said lens system as a whole and the reference symbol D C designates thickness, as measured on the optical axis, of said cemented lens component disposed in said front unit.

Claim 16

Dependent Claim 62 words

A wide-angle lens system according to claim 3 satisfying the following condition (6): 1.0×10.sup.-5 <|Δx|/f<1.0×10.sup.-1( 6) wherein the reference symbol Δx represents a departure from a reference sphere of said aspherical surface at a height at which a marginal ray passes through said aspherical surface and the reference symbol f designates a focal length of said wide-angle lens system as a whole.

Claim 17

Dependent Claim 44 words

A wide-angle lens system according to claim 4, 5, 6, 7, 8 or 9 wherein said front unit comprises at least one aspherical surface having a positive refractive power which is strengthened as portions of said aspherical surface are farther from the optical axis.

Claim 18

Dependent Claim 44 words

A wide-angle lens system according to claim 4, 5, 6, 7, 8 or 9 wherein said rear unit comprises at least one aspherical surface having a positive refractive power which is weakened as portions of said aspherical surface are farther from the optical axis.

Claim 19

Dependent Claim 62 words

A wide-angle lens system according to claim 17 satisfying the following condition (6): 1.0×10.sup.-5 <|Δx|/f<1.0×10.sup.-1( 6) wherein the reference symbol Δx represents a departure from a reference sphere of said aspherical surface at a height at which a marginal ray passes through said aspherical surface and the reference symbol f designates a focal length of said wide-angle lens system as a whole.

Claim 20

Dependent Claim 39 words

A wide-angle lens system according to claim 1, 4, 5, 6 or 7 wherein said rear unit comprises at least one graded refractive index lens component which has a refractive index gradient in a direction along the optical axis.

Claim 21

Dependent Claim 138 words

A wide-angle lens system according to claim 19 wherein said refractive index lens component satisfies the following condition (7): -1<1/(R×N.sub.1)<0 (7) wherein the reference symbol N 1 represents a refractive index distribution coefficient of the first order and the reference symbol R designates a radius of curvature on a surface having a refractive index distribution when said refractive index lens component is made of a homogenous medium within a range from an optional point within this lens component to one surface thereof and another medium having a refractive index distribution within the rest range from said point to the other surface thereof or on a surface whichever has a smaller radius of curvature when a refractive index distribution is imparted over the entire range from one surface to the other surface of said graded refractive index lens component.

Claim 22

Dependent Claim 47 words

A wide-angle lens system according to claim 20 satisfying the following condition (1): -2.0<f/f.sub.1 <-0.2 (1) wherein the reference symbol f represents a focal length of said lens system as a whole and the reference symbol f 1 designates a focal length of said first lens unit.

Claim 23

Dependent Claim 46 words

A wide-angle lens system according to claim 20 satisfying the following condition (2): 0.2<f/f.sub.R <1.0 (2) wherein the reference symbol f represents a focal length of said lens system as a whole and the reference symbol f R designates a focal length of said rear unit.

Claim 24

Dependent Claim 88 words

A wide-angle lens system according to claim 20 satisfying the following condition (3): -1.0<(R.sub.F +R.sub.R)/(R.sub.F -R.sub.R)<0 (3) wherein the reference symbols R F and R R represent radii of curvature on an object side surface and an image side surface respectively of an air lens formed between: an image side surface of the negative lens component which is comprised in the first lens unit and an object side surface of the negative lens component arranged on the object side of the cemented lens component in the front unit.

Claim 25

Dependent Claim 75 words

A wide-angle lens system according to claim 20 satisfying the following condition (4): 0<(R.sub.FS +R.sub.RS)/(R.sub.FS -R.sub.RS)<1.0 (4) wherein the reference symbol R FS represents a radius of curvature on a surface which is disposed on the object side of said stop and closest to said stop, and the reference symbol R RS designates a radius of curvature on a surface which is disposed on the image side of said stop and closest to said stop.

Claim 26

Dependent Claim 56 words

A wide-angle lens system according to claim 20 satisfying the following condition (5): 0.1<D.sub.C /f<1.0 (5) wherein the reference symbol f represents a focal length of said lens system as a whole and the reference symbol D C designates thickness, as measured on the optical axis, of said cemented lens component disposed in said front unit.

Claim 27

Dependent Claim 113 words

A wide-angle lens system comprising, in order from the object side; a front unit comprising a plurality of lens components, a stop and a rear unit having a positive refractive power as a whole; wherein said front unit comprises a lens unit which comprises at least one positive lens component disposed on the object side therein and has a negative refractive power as a whole, and another lens unit which has a positive refractive power, and is disposed between said negative lens unit and said stop, and wherein said rear unit comprises at least one graded refractive index lens component which has a refractive index distribution in a direction along an optical axis.

Claim 28

Dependent Claim 113 words

A wide-angle lens system comprising, in order from the object side; a front unit comprising a plurality of lens components, a stop and a rear unit having a positive refractive power as a whole; wherein said front unit comprises a lens unit which comprises at least one positive lens component disposed on the object side therein and has a negative refractive power as a whole, and another lens unit which has a positive refractive power, and is disposed between said negative lens unit and said stop, and wherein said rear unit comprises at least one graded refractive index lens component which has a refractive index distribution in a direction along an optical axis.

Claim 29

Dependent Claim 46 words

A wide-angle lens system according to claim 26 satisfying the following condition (2): 0.2<f/f.sub.R <1.0 (2) wherein the reference symbol f represents a focal length of said lens system as a whole and the reference symbol f R designates a focal length of said rear unit.

Claim 30

Dependent Claim 88 words

A wide-angle lens system according to claim 26 satisfying the following condition (3): -1.0<(R.sub.F +R.sub.R)/(R.sub.F -R.sub.R)<0 (3) wherein the reference symbols R F and R R represent radii of curvature on an object side surface and an image side surface respectively of an air lens formed between: an image side surface of the negative lens component which is comprised in the first lens unit and an object side surface of the negative lens component arranged on the object side of the cemented lens component in the front unit.

Claim 31

Dependent Claim 75 words

A wide-angle lens system according to claim 26 satisfying the following condition (4): 0<(R.sub.FS +R.sub.RS)/(R.sub.FS -R.sub.RS)<1.0 (4) wherein the reference symbol R FS represents a radius of curvature on a surface which is disposed on the object side of said stop and closest to said stop, and the reference symbol R RS designates a radius of curvature on a surface which is disposed on the image side of said stop and closest to said stop.

Claim 32

Dependent Claim 56 words

A wide-angle lens system according to claim 26 satisfying the following condition (5): 0.1<D.sub.C /f<1.0 (5) wherein the reference symbol f represents a focal length of said lens system as a whole and the reference symbol D C designates thickness, as measured on the optical axis, of said cemented lens component disposed in said front unit.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1999-09-24	2000-03-25	2000-09-24	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2003-09-24	2004-03-25	2004-09-24	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2007-09-24	2008-03-25	2008-09-24	$7700.00	Window Closed / Lapsed

Wide-angle lens system #6

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