Compact high performance zoom lens system
View Patent ↗A compact high performance objective zoom lens system is disclosed that provides optimum optical performance over the entire zoom focal length range at focus distances from close to infinity. The system comprises, from object space to image space, one focusing objective lens group (comprising a focus lens group and a stationary lens group) and three zoom lens groups aligned on the optical axis. The focus lens group and the zoom lens groups are axially movable along the optical axis for focusing and zooming. In one embodiment, the system has a focal length zoom region from about 19 mm to 90 mm, an aperture of F/2.7 and substantially the same optical performance as high quality fixed objective lenses of the same range. The performance characteristics of this system makes it suitable for use with both film and electronic detector cameras.
1. A high performance zoom lens system comprised of a single focusing objective lens group and multiple zoom lens groups aligned in that order on a common optical axis and arranged to collect radiation emanating from an object space and deliver said radiation to an axially stationary image space as a real image, said single focusing objective lens group comprising a focus lens group of negative optical power and a stationary lens group of positive optical power, said multiple zoom lens groups comprising a first zoom lens group of negative optical power, a second zoom lens group of positive optical power and a third zoom lens group of positive optical power and containing an optical stop of said zoom lens system, each of said focus lens group and said first, second and third zoom lens groups being axially movable, and said stationary lens group being axially stationary.
2. The high performance zoom lens system recited in claim 1 , wherein said focus lens group and said stationary lens group have a combined positive optical power.
3. The high performance zoom lens system of claim 1 , wherein said first, second and third zoom lens groups are axially movable in a monotonic manner over a full range of focal lengths between a minimum focal length and a maximum focal length of the zoom lens system.
4. The high performance zoom lens system of claim 1 , wherein said focus lens group includes a non-spherical, non-plano, optically refractive surface.
5. The high performance zoom lens system of claim 4 , wherein said third zoom lens group includes a non-spherical, non-plano, optically refractive surface.
6. The high performance zoom lens system of claim 5 , wherein said zoom lens system has all remaining optically refractive surfaces that are substantially at least one of either spherical or plano.
7. The high performance zoom lens system of claim 1 , wherein said third zoom lens group includes an adjustable iris.
8. The high performance zoom lens system of claim 1 , wherein said focus lens group and said stationary lens group include lens elements for minimizing changes in a size of objects appearing in the real image during changes in focus distance from close to distant objects by axial movement of said focus lens group.
9. The high performance zoom lens system of claim 1 , wherein said focus lens group is comprised of at least three optically refractive lens elements and includes at least one aspherical lens surface.
10. The high performance zoom lens system of claim 1 , wherein said stationary lens group is comprised of at least four optically refractive lens elements.
11. The high performance zoom lens system of claim 1 , wherein said first zoom lens group is comprised of at least four optically refractive lens elements of which one pair of doublet lens elements are included.
12. The high performance zoom lens system of claim 1 , wherein said second zoom lens group is comprised of at least one optically refractive lens element.
13. The high performance zoom lens system of claim 1 , wherein said third zoom lens group is comprised of at least eight optically refractive lens elements and includes at least one aspherical lens surface.
14. The high performance zoom lens system of claim 1 , wherein the zoom lens system includes a lens element having an aspherical lens surface with a profile governed by the following equation and coefficients:
Z
=
(
CURV
)
Y
2
1
+
(
1
-
(
1
+
K
)
(
CURV
)
2
Y
2
)
1
/
2
+
(
A
)
Y
4
+
(
B
)
Y
6
+
(
C
)
Y
8
(
D
)
Y
10
;
wherein
CURV=1/(Radius of Curvature),
Y=Aperture height, measured perpendicular to optical axis,
K, A, B, C, D=Coefficients, and
Z=Position of surface profile for a given Y value, as measured along the optical axis from the pole (i.e. axial vertex) of the surface; and
wherein the coefficients for the surface S 3 of lens 1 are
K=−1.0493E+00,
A=4.1484E−07,
B=1.0025E−11,
C=2.9558E−14, and
D=−7.0724E−18.
15. The high performance zoom lens system of claim 14 , wherein said aspherical lens surface is included in said focus lens group.
16. The high performance zoom lens system of claim 1 , wherein the zoom lens system includes a lens element having an aspherical lens surface with a profile governed by the following equation and coefficients:
Z
=
(
CURV
)
Y
2
1
+
(
1
-
(
1
+
K
)
(
CURV
)
2
Y
2
)
1
/
2
+
(
A
)
Y
4
+
(
B
)
Y
6
+
(
C
)
Y
8
(
D
)
Y
10
;
wherein
CURV=1/(Radius of Curvature),
Y=Aperture height, measured perpendicular to optical axis,
K, A, B, C, D=Coefficients, and
Z=Position of surface profile for a given Y value, as measured along the optical axis from the pole (i.e. axial vertex) of the surface; and
wherein the coefficients for the surface S 26 of lens 13 are
K=0.0000E+00,
A=9.4858E−06,
B=6.2385E−09,
C=5.7827E−12, and
D=1.0431E−14.
17. The high performance zoom lens system of claim 16 , wherein said aspherical lens surface is included in said third zoom lens group.
18. A high performance zoom lens system comprised of a single focusing objective lens group and multiple zoom lens groups aligned in that order on a common optical axis, said single focusing objective lens group having a focus lens group of negative optical power and a stationary lens group of positive optical power, said focus lens group being separately axially moveable along the optical axis and said stationary lens group being axially stationary, said multiple zoom lens groups comprising a first zoom lens group, a second zoom lens group and a third zoom lens group, said first zoom lens group being axially movable in a non-monotonic manner over a full range between minimum and maximum focal lengths, said second zoom lens group being axially movable in a monotonic manner over the full range between minimum and maximum focal lengths, and said third zoom lens group having an optical stop and being axially movable in a monotonic manner over the full range between minimum and maximum focal lengths.
19. The high performance zoom lens system of claim 18 , wherein said focus lens group and said stationary lens group have a combined positive optical power.
20. The high performance zoom lens system of claim 18 , wherein said focus lens group includes a non-spherical, non-plano, optically refractive surface.
21. The high performance zoom lens system of claim 18 , wherein said third zoom lens group includes a non-spherical, non-plano, optically refractive surface.
22. The high performance zoom lens system of claim 18 , wherein said third zoom lens group includes an adjustable iris.
23. The high performance zoom lens system of claim 18 , wherein said focus lens group and said stationary lens group include lens elements for minimizing changes in a size of objects appearing in the real image during changes in focus distance from close to distant objects by axial movement of said focus lens group.
24. A high performance zoom lens system comprised of a single focusing objective lens group and multiple zoom lens groups aligned in that order on a common optical axis and arranged to collect radiation emanating from an object space and deliver said radiation to an axially stationary image space as a real image, said single focusing objective lens group comprising a focus lens group and a stationary lens group, said focus lens group of negative optical power and being axially movable with at least one non-spherical, non-plano, optically refractive surface, said stationary lens group of positive optical power and being axially stationary, said multiple zoom lens groups comprising first, second and third zoom lens groups, said first zoom lens group of negative optical power and being axially movable, said second zoom lens group of positive optical power and being axially movable, and said third zoom lens group being of positive optical power and axially movable with at least one non-spherical, non-plano optically refractive surface and an adjustable optical stop, said zoom lens system having remaining optically refractive surfaces that are substantially at least one of either spherical or plano, and said zoom lens system via axial positioning of said focus lens group and said multiple zoom lens groups providing a high level of optical performance through focusing and zooming ranges at the real image.
25. The high performance zoom lens system of claim 24 , wherein each said non-spherical, non-plano optically refractive surface is an aspherical lens surface.
26. The high performance zoom lens system of claim 24 , wherein said single objective focusing lens group has a combined positive optical power.
27. A high performance zoom lens system comprised of glass lens elements ( 1 ) through ( 20 ) aligned in that order on a common optical axis and arranged to collect radiation emanating from an object space and deliver said radiation to an axially stationary image space as a real image;
said lens elements forming a single objective focusing lens group ( 51 ) comprising a focus lens group ( 52 ), and a stationary lens group ( 53 ), a zoom lens group ( 54 ) comprising a first zoom lens group ( 55 ), a second zoom lens group ( 56 ), and third zoom lens group ( 57 ), said focus lens group and said first, second and third zoom lens groups each being axially movable;
said focus lens group comprising lens elements ( 1 ), ( 2 ) and ( 3 ), said stationary lens group comprising lens elements ( 4 ), ( 5 ), ( 6 ) and ( 7 ), said first zoom lens group comprising lens elements ( 8 ) through ( 11 ), said second zoom lens group comprising lens element ( 12 ), and said third zoom lens group having an optical stop and comprising lens elements ( 13 ) through ( 20 ); and
wherein lens element surfaces, dummy surfaces, an iris at an optical stop, an object plane and an image plane are identified as (O) and (S 1 ) through (S 41 ), said lens element surfaces (S 3 ) and (S 26 ) are aspheric, and said lens elements, lens element surfaces, dummy surfaces, iris at the optical stop, object plane and image plane have the following order, relationships and characteristics:
Thickness
Radius of
or
Sub-
Sur-
Curvature
Separation
Glass
Item
Group
Group
face
(mm)
(mm)
Code
Object
S1
Flat
Infinite
Plane
810.000
352.000
1
51
52
S2
1063.066
3.000
SLAH59
S3
51.696*
20.347
2
51
52
S4
−211.395
2.800
SFPL53
S5
2053.522
0.150
3
51
52
S6
110.458
8.881
STIH6
S7
658.340
1.750
12.972
24.482
4
51
53
S8
123.797
10.542
SPHM53
S9
−169.812
0.125
5
51
53
S10
116.511
2.350
STIH53
6
51
53
S11
45.106
10.911
SFPL51
S12
873.710
0.125
7
51
53
S13
66.583
6.872
SLAH59
S14
973.939
0.764
10.680
16.206
20.264
29.240
8
54
55
S15
151.327
1.450
SLAM3
S16
28.614
6.213
9
54
55
S17
−115.404
1.450
SBSM18
10
54
55
S18
33.001
4.664
STIH53
S19
−11785.600
2.861
11
54
55
S20
−40.025
1.450
SBSM9
S21
140.781
38.107
25.754
17.977
9.877
1.000
12
54
56
S22
49.273
2.549
SLAH58
S23
110.396
18.211
14.155
10.973
6.594
1.637
Stop
54
57
S24
Flat
0.518
13
54
57
S25
43.816
3.253
SFPL51
S26
873.710*
4.116
14
54
57
S27
−35.604
1.450
SNSL36
S28
100.434
1.681
15
54
57
S29
82.308
7.242
SFPL51
S30
−35.982
0.100
16
54
57
S31
41.224
7.435
SFPL53
17
S32
−63.519
0.100
17
54
57
S33
82.450
3.224
SNPH1
18
54
57
S34
−190.474
1.450
SLAH79
S35
26.399
7.305
19
54
57
S36
201.165
1.886
SNPH1
S37
−910.736
0.100
20
54
57
S38
35.778
5.071
SFPL53
S39
−576.303
4.000
10.491
15.926
24.345
29.204
Dummy
S40
Flat
38.500
Surface
Image
S41
Flat
0.000
Plane
28. The high performance zoom lens system of claim 27 , wherein the maximum aperture diameters (mm) at each surface (S 1 ) through (S 41 ), excluding said dummy surfaces, are as follows; 93.00 at (S 2 ), 78.92 at (S 3 ), 78.87 at (S 4 ), 79.21 at (S 5 ), 79.86 at (S 6 ), 79.10 at (S 7 ), 67.85 at (S 8 ), 66.64 at (S 9 ), 58.43 at (S 10 ), 53.56 at (S 11 ), 52.37 at (S 12 ), 50.66 at (S 13 ), 49.49 at (S 14 ), 38.09 at (S 15 ), 32.00 at (S 16 ), 31.76 at (S 17 ), 29.00 at (S 18 ), 28.32 at (S 19 ), 27.96 at (S 20 ), 27.36 at (S 21 ), 28.68 at (S 22 ), 28.65 at (S 23 ), 28.78 at (S 24 ), 29.40 at (S 25 ), 29.26 at (S 26 ), 29.26 at (S 27 ), 31.11 at (S 28 ), 32.60 at (S 29 ), 33.08 at (S 30 ), 32.71 at (S 31 ), 32.14 at (S 32 ), 29.68 at (S 33 ), 28.96 at (S 34 ), 26.42 at (S 35 ), 28.89 at (S 36 ), 29.20 at (S 37 ), 30.77 at (S 38 ), 30.75 at (S 39 ), and 27.80 at (S 41 ).
29. The high performance zoom lens system of claim 27 , wherein said aspheric lens surface S 3 has a profile governed by the following equation and coefficients:
Z
=
(
CURV
)
Y
2
1
+
(
1
-
(
1
+
K
)
(
CURV
)
2
Y
2
)
1
/
2
+
(
A
)
Y
4
+
(
B
)
Y
6
+
(
C
)
Y
8
(
D
)
Y
10
;
wherein
CURV=1/(Radius of Curvature),
Y=Aperture height, measured perpendicular to optical axis,
K, A, B, C, D=Coefficients, and
Z=Position of surface profile for a given Y value, as measured along the optical axis from the pole (i.e. axial vertex) of the surface; and
wherein the coefficients for the surface S 3 of lens 1 are
K=−1.0493E+00,
A=4.1484E−07,
B=1.0025E−11,
C=2.9558E−14, and
D=−7.0724E−18.
30. The high performance zoom lens system of claim 27 , wherein said aspheric lens surface S 26 has a profile governed by the following equation and coefficients:
Z
=
(
CURV
)
Y
2
1
+
(
1
-
(
1
+
K
)
(
CURV
)
2
Y
2
)
1
/
2
+
(
A
)
Y
4
+
(
B
)
Y
6
+
(
C
)
Y
8
(
D
)
Y
10
;
wherein
CURV=1/(Radius of Curvature),
Y=Aperture height, measured perpendicular to optical axis,
K, A, B, C, D=Coefficients, and
Z=Position of surface profile for a given Y value, as measured along the optical axis from the pole (i.e. axial vertex) of the surface; and
wherein the coefficients for the surface S 26 of lens 13 are
K=0.0000E+00,
A=9.4858E−06,
B=6.2385E−09,
C=5.7827E−12, and
D=1.0431E−14.