JP2015028556A - Thin high-magnification zoom lens - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a zoom lens which offers high magnification, a wide view angle, and high performance and which is suitable for full-flat cameras.SOLUTION: A zoom lens includes, in order from the object side, a first group L1 having positive refractive power, a second group L2 having negative refractive power, a third group L3 having positive refractive power, and a succeeding lens group, where the succeeding lens group has a group L5 having positive refractive power on the most image side therein and the first group has a reflective member. The first group is stationary while the second and third groups move while zooming. The first group has a negative lens on the object side of the reflective member and two positive lenses on the image side of the reflective member, and the group on the most image side has two positive lenses and one negative lens. The zoom lens satisfies the following conditional expressions: 0.2<f1/ft<0.4...(1), (image)...(2), 0.15<fa/ft<0.4...(3).

Description

  The present invention relates to a digital camera, a digital single-lens reflex camera, a digital video camera, and the like, and more particularly to a zoom lens suitable for a digital camera.

  In recent years, waterproof and dustproof digital cameras have been demanded. That is, a digital camera is a precision device, and if water or dust enters inside, it becomes a cause of failure. For this reason, it is necessary to devise a method for reducing the water and dust entry paths as much as possible. As an example, there is known a full flat camera in which the lens barrel does not jump out of the camera body at the time of shooting and water or dust is difficult to enter from the lens barrel (the lens barrel does not jump out of the camera body at the time of shooting). In addition, in order to respond to various uses of users, there is a demand for further thinner cameras, wider angle of view, and higher magnification.

  However, wide lens zoom lenses tend to increase the front lens diameter. In addition, a high-power zoom lens generally has a long photographing length, which increases the thickness of the camera and impairs portability. As a high-power zoom lens, a type having a positive group, a negative group, and a positive group in order from the object is known. However, the overall length of the lens generally increases as the magnification increases, and the front increases as the field angle increases. The problem is that the ball diameter increases. For this reason, a full flat camera with a wide field angle and a high magnification generally arranges a reflecting member in one group of zoom lenses to bend the optical path inside the camera and reduce the camera thickness.

  However, as the field of view increases, the effective diameter of the reflecting member arranged in one group of zoom lenses also increases, which obstructs the thinning of the camera in order to increase the size.

  For example, Patent Documents 1 and 2 disclose a zoom lens having one group having positive refracting power, two groups having negative refracting power, and three groups having positive refracting power, each having a reflecting member. ing.

JP 2007-248952 A JP 2009-236973 A

  However, in order to dispose the reflecting member in the zoom lens, a space for it is necessary, and in order to reduce the camera thickness after bending, the reflecting member must be inserted further in front of the lens. For this reason, the entrance pupil position becomes deep, and the front lens diameter becomes larger than before the reflection member is inserted. Further, when the power of one group is increased to achieve a wide angle of view, the axial chromatic aberration at the telephoto end is particularly reduced. In order to reduce the thickness of the camera, it is desirable to dispose the reflecting member closest to the object side. However, in order to increase the effective diameter of the reflecting member and increase the size, a negative lens is disposed on the object side of the reflecting member. Is common. In general, the positive lens group is disposed on the image side of the reflecting member.

  Further, since the distance between the negative lens and the positive lens in one group increases, it is difficult to simultaneously correct axial chromatic aberration and lateral chromatic aberration generated in one group.

  Patent Document 1 has a half angle of view of about 30 ° at the wide angle end, which is smaller than the target of about 37 ° of the present application, and has not achieved a sufficiently wide angle of view.

  Although Patent Document 2 achieves a wide angle of view, the size reduction is not sufficient. In order to reduce the size, it is necessary to increase the power of each group, but in order to correct axial chromatic aberration and lateral chromatic aberration that occur in one group, two groups use low dispersion anomalous dispersion glass. In general, low-dispersion glass has a low refractive index. Therefore, when the power is increased, the radius of curvature becomes too small, making it difficult to correct aberrations.

  Conventionally, regarding a zoom lens used in a full-flat camera with a high magnification in view of this point, a technique for maintaining optical performance while widening the angle of view while arranging a reflecting member in one group has not been proposed.

  An object of the present invention is to provide a zoom lens suitable for a full flat camera having a wide angle of view, high magnification, and high performance while having a reflecting member.

  In the present application, the focal length of one group is reduced in order to widen the angle of view. The lateral chromatic aberration that occurs at that time is corrected by overcorrecting the lateral chromatic aberration with the positive group closest to the image side. Also, by reducing the focal length of the positive group closest to the object side, the lateral magnification is reduced and a wide angle of view is achieved.

In order from the object side, there are 1 group of positive refracting power, 2 groups of negative refracting power, 3 groups of positive refracting power, and subsequent lens group, and the most image side group among the following lens groups is positive It has refractive power, has a reflecting member in one group, 1 group is fixed at zooming, 2 groups, 3 groups move, 1 group has a negative lens closer to the object side than the reflecting member, and the reflecting member A zoom lens having two positive lenses closer to the image side, the most image side group having two positive lenses and one negative lens, satisfying the following conditional expression:

       0.2 <f1 / ft <0.4 (1)

0.15 <fa / ft <0.4 (3)
However,
f1: 1 group focal length
fa: Focal length of the most image side group
ft: focal length of the entire system at the telephoto end νai: Abbe number of the lens in the most image side group φai: power of the lens in the most image side group φw: total system power at the wide angle end

  According to the present invention, it is possible to provide a zoom lens suitable for a full flat camera with a high magnification, a wide angle of view, and chromatic aberration correction.

Schematic diagram of a zoom lens using a reflective member Sectional view at the wide-angle end of Numerical Example 1 Aberration diagram at the wide-angle end in Numerical Example 1 Aberration diagram at the telephoto end in Numerical Example 1 Sectional view at the wide-angle end of Numerical Example 2 Aberration diagram at the wide-angle end in Numerical Example 2 Aberration diagram at the telephoto end in Numerical Example 2 Sectional view at the wide-angle end of Numerical Example 3 Aberration diagram at the wide-angle end in Numerical Example 3 Aberration diagram at the telephoto end in Numerical Example 3 Sectional view at the wide-angle end of Numerical Example 4 Aberration diagram at the wide-angle end in Numerical Example 4 Aberration diagram at the telephoto end in Numerical Example 4 Sectional view at the wide-angle end of Numerical Example 5 Aberration diagram at the wide-angle end in Numerical Example 5 Aberration diagram at the telephoto end in Numerical Example 5

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a schematic diagram of a zoom lens using a reflecting member. 2, 5, 8, 11, and 14 are cross-sectional views at the wide-angle end of Numerical Examples 1 to 5 according to the embodiment of the present invention. 3, 6, 9, 12, and 15 are aberration diagrams at the wide-angle end of Numerical Examples 1 to 5 according to the embodiment of the present invention. 4, 7, 10, 13, and 16 are aberration diagrams at the telephoto end of Numerical Examples 1 to 5 according to the embodiment of the present invention.

  With the structure shown in FIG. 1, the optical path is bent in the vertical direction to reduce the camera thickness. Although numerical examples 1 to 5 are not described in FIGS. 2, 5, 8, 11, and 14 as if the optical path is actually bent, the structure is the same as that in FIG. The thickness is shortened.

  In each lens cross-sectional view, PR represents a prism as a reflecting member, GB represents a glass block, SP represents a diaphragm, and IP represents an image plane.

  In each aberration diagram, d and g represent d-line and g-line, respectively, and ΔM and ΔS represent a meridional image plane and a sagittal image plane. The lateral chromatic aberration is represented by the g-line.

  Examples 1 to 5 are composed of a positive group, a negative group, a positive group, a negative group, and a positive group in order from the object side. The reflecting member is used in one group, and is more negative on the object side than the first group of reflecting members. A lens is placed.

  In the present application, the focal length of one group is reduced in order to widen the angle of view. Further, the effective diameter of the reflecting member is reduced by disposing a negative lens on the object side of the reflecting member in the first group. The lateral chromatic aberration that occurs at that time is corrected by overcorrecting the lateral chromatic aberration with the positive group closest to the image side.

  In addition, by reducing the focal length of the positive group closest to the image side, the lateral magnification is reduced and the wide angle is achieved. A zoom lens suitable for a full flat camera with high magnification, wide angle of view, and chromatic aberration is achieved.

  Hereinafter, each embodiment will be described one by one.

[Example 1]
Hereinafter, a lens configuration according to the first embodiment of the present invention will be described with reference to FIG. In Example 1 shown in FIG. 1, in order from the object side, the first positive lens unit L1, the second negative lens unit L2, the stop SP, the third positive lens unit L3, the fourth negative lens unit L4, and the fifth positive lens unit. L5 and glass block GB.

  The focal length of one group and the total focal length at the telephoto end satisfy the following conditional expression.

0.2 <f1 / ft <0.4 (1)
Conditional expression (1) defines the ratio of the focal length of one group to the focal length at the telephoto end. This power arrangement contributes to a wider angle of view.

  Exceeding the upper limit is not preferable because the focal length of one group becomes too large and it becomes difficult to widen the angle of view.

  If the lower limit is exceeded, the focal length of the first group becomes small, the power of the positive lens in the first group becomes too strong, and it becomes difficult to correct axial chromatic aberration and spherical aberration that occur in the first group. It is not preferable.

  More preferably, when the conditional expression (1a) is satisfied, the wide angle of view and the lateral chromatic aberration can be corrected more satisfactorily.

0.25 <f1 / ft <0.4 (1a)
The lens in the most image side group satisfies the following conditional expression.

Conditional expression (2) defines the achromatic condition of the most image side group. The most image side group is a positive group, and normally the value of the expression (2) is a positive sign. If it is attempted to correct the lateral chromatic aberration at the wide-angle end generated by the negative lens in the first group by using the positive lens in the first group, it is difficult to correct the longitudinal chromatic aberration. Therefore, in the state where axial chromatic aberration is corrected, lateral chromatic aberration is corrected by overcorrecting the most image side positive group on the image side of the stop.

  Exceeding the upper limit is not preferable because the achromatic power of the group closest to the image side becomes small and it becomes difficult to correct lateral chromatic aberration generated in one group.

  Exceeding the lower limit is not preferable because the achromatic power of the group closest to the image side becomes large and correction of lateral chromatic aberration occurring in one group becomes excessive.

  More preferably, when the conditional expression (2a) is satisfied, the lateral chromatic aberration can be corrected more satisfactorily.

The focal length of the most image side group and the telephoto end satisfies the following conditional expression.
0.15 <fa / ft <0.4 (3)
Conditional expression (3) defines the ratio of the focal distance between the most image side group and the telephoto end. By reducing the focal length of the positive group closest to the image side, the lateral magnification is reduced, which contributes to a wider angle of view.
Exceeding the upper limit is not preferable because the focal length of the group closest to the image side becomes large and it becomes difficult to widen the angle of view.

Exceeding the lower limit is not preferable because the focal length of the group closest to the image side becomes small, and it becomes difficult to overcorrect the achromatism in the group closest to the image side. Thus, the object of the present invention can be achieved.
More preferably, when the conditional expression (3a) is satisfied, the wide angle of view and the lateral chromatic aberration can be corrected more satisfactorily.
0.18 <fa / ft <0.4 (3a)
Thus, the object of the present invention can be achieved. Desirably, the following conditional expression is satisfied because the lateral chromatic aberration can be satisfactorily corrected.

However, the power of the strongest negative lens of φn1: 1 group
vn1: The Abbe number of the strongest negative lens in the 1 group.
Conditional expression (4) regulates the balance between the achromatic lens of the first lens group and the most achromatic group. Exceeding the upper limit is not preferable because the lateral chromatic aberration generated in the negative lens of one group becomes larger than the lateral chromatic aberration of the most image side group and it becomes difficult to correct.

  Exceeding the lower limit is not preferable because the achromaticity of the group closest to the image side is excessively corrected and it becomes difficult to correct lateral chromatic aberration.

  More preferably, when the conditional expression (4a) is satisfied, the lateral chromatic aberration can be corrected more satisfactorily.

  So far, the method for correcting the lateral chromatic aberration generated in one group by overcorrecting the positive group closest to the image side has been described. Since correction can be made by increasing the achromatic action of the negative lens on the image side relative to the stop, correction of chromatic aberration of magnification may be shared not only by the most image side group but also by the negative lens in the object side group. In this embodiment, the lateral chromatic aberration correction is shared by the negative group closest to the image side.

Desirably, the following conditional expression is satisfied because the lateral chromatic aberration can be satisfactorily corrected.
30 <vnb <50 (5)
However,
vnb: Abbe number of the most powerful negative lens in the negative group closest to the image side.

Conditional expression (5) defines an appropriate Abbe number range to enhance the achromatic action of the negative lens.
Exceeding the upper limit is not preferable because the achromatic action of the negative lens is reduced and the contribution to the lateral chromatic aberration correction is reduced.

  Exceeding the lower limit is not preferable because the achromatic action of the negative lens increases and overcorrection occurs.

More preferably, when the conditional expression (5a) is satisfied, the lateral chromatic aberration can be corrected more satisfactorily.
32 <vnb <48 (5a)
Desirably, the following conditional expression is satisfied because the lateral chromatic aberration can be satisfactorily corrected.
-0.3 <fb / ft <-0.1 (6)
However,
fb: The focal length of the negative group closest to the image side If the upper limit is exceeded, the focal length of the negative group increases, the achromatic power of the negative group decreases, and it becomes difficult to correct lateral chromatic aberration. It is not preferable.

  Exceeding the lower limit is not preferable because the focal length of the negative group becomes small, the achromatic power of the negative group becomes excessive, and it becomes difficult to correct lateral chromatic aberration.

More preferably, when the conditional expression (6a) is satisfied, the lateral chromatic aberration can be corrected more satisfactorily.
-0.3 <fb / ft <-0.12 (6a)
In order from the object side, it consists of 1 group with positive refractive power, 2 groups with negative refractive power, 3 groups with positive refractive power, 4 groups with negative refractive power, and 5 groups with positive refractive power By doing so, the power arrangement of each group can be set appropriately.

[Example 2]
Hereinafter, a lens configuration according to the second embodiment of the present invention will be described with reference to FIG. In Example 2 shown in FIG. 4, in order from the object side, the first positive lens unit L1, the second negative lens unit L2, the stop, the third positive lens unit L3, the fourth negative lens unit L4, and the fifth positive lens unit L5. It consists of a glass block, GB.

  In Example 2, compared with Example 1, the F value at the telephoto end is darkened to 5.6. In this numerical example, the effective diameter of the positive lens in one group is determined by the F value at the telephoto end. By making it dark, the effective diameter is reduced to achieve miniaturization. In addition, the power of L1, L4, and L5 is reduced.

[Example 3]
Hereinafter, the lens configuration according to the third embodiment of the present invention will be described with reference to FIG. In Example 3 shown in FIG. 7, in order from the object side, the first positive lens unit L1, the second negative lens unit L2, the stop, the third positive lens unit L3, the fourth negative lens unit L4, and the fifth positive lens unit L5. It consists of a glass block, GB.

  In the third embodiment, the powers of L1 and L5 are made stronger than in the first embodiment. While increasing the power of L5, the achromatic effect of L5 is enhanced.

[Example 4]
Hereinafter, the lens configuration according to the fourth embodiment of the present invention will be described with reference to FIG. In Example 4 shown in FIG. 10, in order from the object side, the first positive lens unit L1, the second negative lens unit L2, the stop, the third positive lens unit L3, the fourth negative lens unit L4, and the fifth positive lens unit L5. It consists of a glass block, GB.

  The power of L5 is stronger in Example 4 than in Example 1. The lateral chromatic aberration is corrected by L5, which is the most image side group.

[Example 5]
Hereinafter, the lens configuration according to the fifth example of the present invention will be described with reference to FIG. In Example 5 shown in FIG. 13, in order from the object side, the first positive lens unit L1, the second negative lens unit L2, the stop, the third positive lens unit L3, the fourth negative lens unit L4, and the fifth positive lens unit L5. It consists of a glass block, GB.

  In Example 5, compared with Example 1, the power of L1 is small. The numerical value of the conditional expression (3) is the smallest among the numerical examples, and the power of L5, which is the most image side group, is strong. In addition, the numerical value of conditional expression (6) is small, and the power of L4, which is the object side group of the most image side group, is strong. However, the numerical value of conditional expression (2) is small in the numerical examples. As described above, the power of L1 is strengthened and the power of L4 and L5 is strengthened, and while the chromatic aberration of magnification is L1 at L5, the achromatic share is also assigned to L4.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

  Next, numerical examples of the present invention will be shown.

In the numerical example, ri is the radius of curvature of the i-th lens surface in order from the object side, di is the i-th lens thickness or air spacing, and ndi and vdi are the refractive indices of the d-line of the i-th lens material. And the Abbe number. The aspherical shape has a radius of curvature at the center of the lens surface as R, the optical axis direction as the X-axis, the direction perpendicular to the optical axis as the Y-axis, and the aspheric coefficient as Ai (i = 1, 2, 3... )
X = (1 / R) Y2
1+ {1- (K + 1) (Y / R) 2} 1/2
+ A4Y4 + A6Y6 + A8Y8 + A10Y10 + ...
It shall be represented by

  Table 1 shows the relationship between the above-described conditional expressions of the present invention and numerical examples.

Numerical example 1
Unit mm

Surface data surface number rd nd vd Effective diameter
1 79.161 1.01 1.92286 20.9 18.05
2 15.900 2.50 15.84
3 ∞ 15.00 1.90366 31.3 15.62
4 ∞ 0.19 14.84
5 36.978 3.04 1.59282 68.6 15.37
6 -25.494 0.19 15.53
7 * 25.555 1.95 1.69350 53.2 15.19
8 * -345.688 (variable) 14.97
9 -26.381 0.44 1.85400 40.4 7.05
10 * 10.355 1.36 6.82
11 -10.317 0.44 1.72916 54.7 6.87
12 42.257 0.16 7.37
13 41.585 1.18 1.92286 18.9 7.53
14 -27.078 (variable) 7.79
15 (Aperture) ∞ (Variable) 8.12
16 * 10.690 1.95 1.69350 53.2 8.57
17 * 58.487 1.60 8.46
18 20.722 0.50 1.83481 42.7 8.48
19 8.251 2.61 1.49700 81.5 8.26
20 -11.103 (variable) 8.28
21 16.067 0.44 1.88300 40.8 5.64
22 6.325 (variable) 5.47
23 10.645 2.21 1.51742 52.4 8.86
24 -22.123 0.55 1.92286 20.9 8.78
25 18.121 0.16 8.79
26 * 17.453 2.45 1.58313 59.4 8.89
27 -12.712 (variable) 9.06
28 ∞ 1.29 1.51633 64.2 20.00
29 ∞ (variable) 20.00
Image plane ∞

Aspheric data 7th surface
K = 0.00000e + 000 A 4 = 3.71143e-006 A 6 = -2.44162e-008 A 8 = -3.73467e-009 A10 = 1.91671e-011

8th page
K = 0.00000e + 000 A 4 = 9.06789e-006 A 6 = -1.13302e-007 A 8 = -3.27643e-009 A10 = 2.51291e-011

10th page
K = 0.00000e + 000 A 4 = -1.40586e-004 A 6 = 2.14541e-006 A 8 = 1.11525e-008 A10 = -4.75224e-009

16th page
K = 0.00000e + 000 A 4 = 5.95526e-005 A 6 = -6.68120e-006 A 8 = 2.64364e-007 A10 = -1.32680e-008

17th page
K = 0.00000e + 000 A 4 = 3.53464e-004 A 6 = -6.43741e-006 A 8 = 1.90601e-007 A10 = -1.28089e-008

26th page
K = 0.00000e + 000 A 4 = -3.74153e-005 A 6 = 5.69321e-006 A 8 = -2.71745e-007 A10 = 4.25627e-009

Various data Zoom ratio 9.97
Wide angle Medium telephoto focal length 5.01 10.35 50.00
F number 3.61 4.50 5.00
Angle of view 34.29 20.53 4.43
Image height 3.42 3.88 3.88
Total lens length 82.00 82.00 82.00
BF 1.36 1.36 1.36

d 8 0.38 6.72 13.35
d14 13.47 7.13 0.50
d15 8.45 6.70 0.19
d20 4.91 6.66 13.17
d22 7.08 6.35 10.73
d27 5.15 5.88 1.50
d29 1.36 1.36 1.36

Entrance pupil position 12.38 18.18 28.25
Exit pupil position 138.57 1407.68 141.62
Front principal point position 17.58 28.60 96.07
Rear principal point position -3.65 -8.99 -48.64

Zoom lens group data group Start surface Focal length Lens configuration length Front principal point position Rear principal point position
1 1 17.45 23.88 14.64 7.99
2 9 -6.92 3.57 0.18 -2.54
Aperture 15 ∞ 0.00 0.00 -0.00
3 16 11.55 6.66 2.19 -3.23
4 21 -12.07 0.44 0.39 0.15
5 23 17.62 5.37 1.97 -1.79
GB 28 ∞ 1.29 0.42 -0.42

Single lens Data lens Start surface Focal length
1 1 -21.72
2 3 0.00
3 5 25.92
4 7 34.39
5 9 -8.66
6 11 -11.33
7 13 17.92
8 16 18.55
9 18 -16.73
10 19 9.97
11 21 -12.07
12 23 14.22
13 24 -10.72
14 26 13.00
15 28 0.00

Numerical example 2
Unit mm

Surface data surface number rd nd vd Effective diameter
1 108.061 1.01 1.92286 20.9 17.96
2 16.952 2.34 15.89
3 ∞ 15.00 1.90366 31.3 15.68
4 ∞ 0.19 13.70
5 38.395 2.84 1.59282 68.6 13.67
6 -26.903 0.19 13.46
7 * 26.259 1.68 1.69350 53.2 13.21
8 * -168.801 (variable) 13.02
9 -25.990 0.44 1.85400 40.4 6.98
10 * 10.752 1.18 6.35
11 -10.072 0.44 1.72916 54.7 6.24
12 43.073 0.15 6.46
13 40.393 1.08 1.92286 18.9 6.59
14 -27.104 (variable) 6.82
15 (Aperture) ∞ (Variable) 7.27
16 * 10.300 2.19 1.69350 53.2 7.94
17 * 58.367 1.91 7.74
18 23.527 0.50 1.83481 42.7 7.65
19 8.127 2.23 1.49700 81.5 7.46
20 -11.452 (variable) 7.47
21 15.025 0.44 1.88300 40.8 5.89
22 6.426 (variable) 5.70
23 11.956 2.09 1.51742 52.4 8.78
24 -22.421 0.55 1.92286 20.9 8.79
25 19.760 0.19 8.92
26 * 18.249 2.50 1.58313 59.4 9.09
27 -12.783 (variable) 9.28
28 ∞ 1.29 1.51633 64.2 20.00
29 ∞ (variable) 20.00
Image plane ∞

Aspheric data 7th surface
K = 0.00000e + 000 A 4 = 8.15995e-006 A 6 = -8.14762e-008 A 8 = -2.19361e-009 A10 = -1.18258e-012

8th page
K = 0.00000e + 000 A 4 = 1.46986e-005 A 6 = -1.56358e-007 A 8 = -2.51962e-009 A10 = 1.32712e-011

10th page
K = 0.00000e + 000 A 4 = -1.36094e-004 A 6 = 2.30129e-006 A 8 = 6.92089e-008 A10 = -8.74253e-009

16th page
K = 0.00000e + 000 A 4 = 4.24228e-005 A 6 = -3.63882e-006 A 8 = 2.12998e-007 A10 = -1.01398e-008

17th page
K = 0.00000e + 000 A 4 = 3.30095e-004 A 6 = -3.82480e-006 A 8 = 2.13981e-007 A10 = -1.21624e-008

26th page
K = 0.00000e + 000 A 4 = -5.19504e-006 A 6 = 4.87132e-006 A 8 = -2.15386e-007 A10 = 3.06326e-009

Various data Zoom ratio 9.51
Wide angle Medium Telephoto focal length 5.15 10.35 49.00
F number 3.61 4.50 5.60
Angle of view 33.59 20.53 4.52
Image height 3.42 3.88 3.88
Total lens length 83.50 83.50 83.50
BF 1.36 1.36 1.36

d 8 0.80 6.98 13.56
d14 13.76 7.58 1.00
d15 9.54 7.76 1.00
d20 4.95 6.73 13.49
d22 7.36 6.76 11.16
d27 5.30 5.90 1.50
d29 1.36 1.36 1.36

Entrance pupil position 12.52 18.29 28.45
Exit pupil position 106.26 286.67 130.80
Front principal point position 17.92 29.01 96.00
Rear principal point position -3.79 -8.99 -47.64

Zoom lens group data group Start surface Focal length Lens configuration length Front principal point position Rear principal point position
1 1 17.78 23.26 14.58 8.18
2 9 -7.02 3.28 0.16 -2.30
Aperture 15 ∞ 0.00 0.00 -0.00
3 16 12.04 6.83 2.09 -3.57
4 21 -13.02 0.44 0.41 0.18
5 23 18.38 5.33 2.17 -1.54
GB 28 ∞ 1.29 0.42 -0.42

Single lens Data lens Start surface Focal length
1 1 -21.90
2 3 0.00
3 5 27.12
4 7 32.88
5 9 -8.86
6 11 -11.16
7 13 17.71
8 16 17.70
9 18 -15.09
10 19 9.94
11 21 -13.02
12 23 15.39
13 24 -11.31
14 26 13.29
15 28 0.00


Numerical example 3
Unit mm

Surface data surface number rd nd vd Effective diameter
1 41.055 1.00 1.92286 20.9 18.98
2 13.504 3.12 16.31
3 ∞ 15.00 1.90366 31.3 16.08
4 ∞ 0.20 13.87
5 99.600 2.38 1.59282 68.6 13.87
6 -24.727 0.20 13.80
7 * 29.215 1.91 1.69350 53.2 12.94
8 * -64.855 (variable) 12.58
9 -17.579 0.45 1.85400 40.4 7.42
10 * 13.946 1.09 6.84
11 -11.057 0.45 1.72916 54.7 6.78
12 78.292 0.07 6.80
13 52.976 1.02 1.92286 18.9 6.82
14 -23.992 (variable) 6.81
15 (Aperture) ∞ (Variable) 6.84
16 * 9.329 2.12 1.69350 53.2 8.20
17 * 112.351 2.00 7.92
18 94.827 0.50 1.88300 40.8 7.71
19 8.037 2.47 1.49700 81.5 7.58
20 -10.788 (variable) 7.71
21 20.179 0.45 1.91082 35.3 6.59
22 5.170 1.23 1.80809 22.8 6.34
23 7.765 (variable) 6.25
24 7.778 2.50 1.49700 81.6 8.27
25 -17.911 0.00 8.16
26 -17.911 0.50 1.92286 18.9 8.16
27 36.822 0.66 8.16
28 * 98.028 1.07 1.58313 59.4 8.28
29 -18.442 (variable) 8.31
30 ∞ 1.29 1.51633 64.2 20.00
31 ∞ (variable) 20.00
Image plane ∞

Aspheric data 7th surface
K = 0.00000e + 000 A 4 = -1.30581e-005 A 6 = -6.50977e-009 A 8 = -3.65803e-009 A10 = 3.26510e-011

8th page
K = 0.00000e + 000 A 4 = -2.08951e-005 A 6 = -3.41374e-008 A 8 = -3.15099e-009 A10 = 3.43401e-011

10th page
K = 0.00000e + 000 A 4 = -1.37868e-004 A 6 = 7.78210e-006 A 8 = -7.54029e-007 A10 = 2.70248e-008

16th page
K = 0.00000e + 000 A 4 = 9.37161e-005 A 6 = 5.32058e-006 A 8 = -1.28408e-007 A10 = 1.19439e-008

17th page
K = 0.00000e + 000 A 4 = 3.86335e-004 A 6 = 5.74722e-006 A 8 = -1.16724e-007 A10 = 1.61236e-008

28th page
K = 0.00000e + 000 A 4 = -3.59684e-005 A 6 = 2.34096e-005 A 8 = -1.76175e-006 A10 = 4.53994e-008

Various data Zoom ratio 9.79
Wide angle Medium Telephoto focal length 5.01 10.56 49.00
F number 3.61 4.50 6.00
Angle of view 33.35 20.16 4.52
Image height 3.29 3.88 3.88
Total lens length 84.96 84.96 84.96
BF 1.36 1.36 1.36

d 8 0.75 7.68 14.70
d14 14.89 7.97 0.94
d15 12.44 10.07 0.97
d20 6.87 9.24 18.34
d23 2.28 2.01 5.50
d29 4.67 4.95 1.45
d31 1.36 1.36 1.36

Entrance pupil position 12.85 18.83 28.46
Exit pupil position -98.03 -56.89 -69.32
Front principal point position 17.60 27.47 43.49
Rear principal point position -3.64 -9.19 -47.64

Zoom lens group data group Start surface Focal length Lens configuration length Front principal point position Rear principal point position
1 1 18.62 23.82 15.57 9.39
2 9 -7.94 3.08 0.01 -2.28
Aperture 15 ∞ 0.00 0.00 -0.00
3 16 14.00 7.09 1.44 -4.43
4 21 -13.21 1.68 1.32 0.37
5 24 19.00 4.73 0.65 -2.83
GB 30 ∞ 1.29 0.42 -0.42

Single lens Data lens Start surface Focal length
1 1 -22.19
2 3 0.00
3 5 33.66
4 7 29.29
5 9 -9.05
6 11 -13.26
7 13 18.01
8 16 14.55
9 18 -9.97
10 19 9.69
11 21 -7.74
12 22 15.80
13 24 11.28
14 26 -13.00
15 28 26.71
16 30 0.00


Example 4
Unit mm

Surface data surface number rd nd vd Effective diameter
1 135.231 1.00 1.92286 20.9 16.11
2 13.929 2.05 14.02
3 ∞ 15.00 1.90366 31.3 13.95
4 ∞ 0.20 13.12
5 55.472 2.63 1.59282 68.6 13.45
6 -22.564 0.20 13.73
7 * 22.403 2.19 1.69350 53.2 13.74
8 * -46.701 (variable) 13.61
9 -17.167 0.45 1.85400 40.4 6.82
10 * 12.765 1.12 6.65
11 -10.093 0.45 1.72916 54.7 6.67
12 40.788 0.14 7.10
13 122.610 1.03 1.92286 18.9 7.13
14 -19.464 (variable) 7.36
15 (Aperture) ∞ (Variable) 7.80
16 * 9.388 2.75 1.69350 53.2 9.39
17 * 1307.979 1.79 8.96
18 208.244 0.50 1.88300 40.8 8.63
19 7.967 2.81 1.49700 81.5 8.43
20 -10.577 (variable) 8.55
21 257.987 0.45 1.81600 46.6 7.12
22 5.684 1.29 1.80809 22.8 6.94
23 8.786 (variable) 6.86
24 8.809 2.50 1.49700 81.6 9.29
25 -26.729 0.00 9.19
26 -45.591 0.50 1.92286 18.9 9.13
27 14.027 0.13 8.99
28 * 11.323 2.53 1.58313 59.4 9.11
29 -16.855 (variable) 9.21
30 ∞ 1.29 1.51633 64.2 20.00
31 ∞ (variable) 20.00
Image plane ∞

Aspheric data 7th surface
K = 0.00000e + 000 A 4 = -2.35437e-005 A 6 = 8.27235e-008 A 8 = -5.97621e-009 A10 = 1.55168e-012

8th page
K = 0.00000e + 000 A 4 = -1.12927e-005 A 6 = 7.27507e-008 A 8 = -5.14446e-009 A10 = 6.41552e-012

10th page
K = 0.00000e + 000 A 4 = -2.80141e-004 A 6 = 2.99815e-006 A 8 = -6.48903e-007 A10 = 3.03380e-008

16th page
K = 0.00000e + 000 A 4 = 2.67281e-005 A 6 = 3.00213e-006 A 8 = -1.43809e-007 A10 = 7.78290e-009

17th page
K = 0.00000e + 000 A 4 = 3.11904e-004 A 6 = 5.20903e-006 A 8 = -3.20149e-007 A10 = 1.51599e-008

28th page
K = 0.00000e + 000 A 4 = -2.01453e-004 A 6 = 4.31874e-006 A 8 = -3.48339e-007 A10 = 6.85234e-009

Various data Zoom ratio 9.78
Wide angle Medium Telephoto focal length 5.01 10.36 49.00
F number 3.61 4.50 6.00
Angle of view 33.31 20.50 4.52
Image height 3.29 3.88 3.88
Total lens length 84.96 84.96 84.96
BF 1.36 1.36 1.36

d 8 0.77 5.61 10.17
d14 10.29 5.45 0.88
d15 13.49 10.87 0.84
d20 6.83 9.44 19.48
d23 2.67 3.03 7.60
d29 6.56 6.20 1.63
d31 1.36 1.36 1.36

Entrance pupil position 10.83 14.70 20.23
Exit pupil position 111.61 338.95 78.17
Front principal point position 16.07 25.38 100.49
Rear principal point position -3.65 -9.00 -47.64

Zoom lens group data group Start surface Focal length Lens configuration length Front principal point position Rear principal point position
1 1 13.00 23.28 12.93 7.76
2 9 -6.72 3.18 0.11 -2.28
Aperture 15 ∞ 0.00 0.00 -0.00
3 16 13.91 7.86 1.55 -4.86
4 21 -11.11 1.74 0.98 0.02
5 24 14.14 5.66 1.49 -2.48
GB 30 ∞ 1.29 0.42 -0.42

Single lens Data lens Start surface Focal length
1 1 -16.89
2 3 0.00
3 5 27.40
4 7 22.12
5 9 -8.51
6 11 -11.05
7 13 18.27
8 16 13.62
9 18 -9.39
10 19 9.63
11 21 -7.13
12 22 16.81
13 24 13.65
14 26 -11.58
15 28 12.01
16 30 0.00


Example 5
Unit mm

Surface data surface number rd nd vd Effective diameter
1 101.743 1.00 1.92286 20.9 16.34
2 13.934 2.15 14.23
3 ∞ 15.00 1.90366 31.3 14.14
4 ∞ 0.20 12.95
5 55.359 2.03 1.59282 68.6 13.26
6 -23.845 0.20 13.41
7 * 22.252 2.62 1.69350 53.2 13.45
8 * -43.391 (variable) 13.24
9 -14.960 0.45 1.85400 40.4 6.59
10 * 13.989 1.13 6.46
11 -10.928 0.45 1.72916 54.7 6.49
12 27.029 0.20 6.86
13 93.542 0.97 1.92286 18.9 6.90
14 -19.302 (variable) 7.10
15 (Aperture) ∞ (Variable) 7.52
16 * 9.485 2.73 1.69350 53.2 9.80
17 * 126.747 1.35 9.34
18 72.753 0.50 1.88300 40.8 9.12
19 7.901 3.65 1.49700 81.5 8.86
20 -11.568 (variable) 9.08
21 -33.706 0.45 1.88300 40.8 6.89
22 6.786 1.54 1.80809 22.8 6.92
23 9.685 (variable) 7.04
24 8.630 2.50 1.49700 81.6 9.08
25 -20.565 0.00 9.10
26 -21.231 0.50 1.94595 18.0 9.09
27 26.989 -0.00 9.25
28 * 10.287 2.41 1.65160 58.5 9.61
29 -14.664 (variable) 9.62
30 ∞ 1.29 1.51633 64.2 20.00
31 ∞ (variable) 20.00
Image plane ∞

Aspheric data 7th surface
K = 0.00000e + 000 A 4 = -2.40130e-005 A 6 = -4.17236e-008 A 8 = -9.34210e-009 A10 = 2.05758e-011

8th page
K = 0.00000e + 000 A 4 = -1.14644e-005 A 6 = -1.93832e-007 A 8 = -5.73500e-009 A10 = 1.71049e-011

10th page
K = 0.00000e + 000 A 4 = -3.56628e-004 A 6 = 5.28447e-006 A 8 = -8.58656e-007 A10 = 3.47701e-008

16th page
K = 0.00000e + 000 A 4 = 1.38639e-005 A 6 = 3.80827e-006 A 8 = -1.86125e-007 A10 = 7.70178e-009

17th page
K = 0.00000e + 000 A 4 = 2.60588e-004 A 6 = 6.33381e-006 A 8 = -3.75373e-007 A10 = 1.48541e-008

28th page
K = 0.00000e + 000 A 4 = -3.91934e-004 A 6 = 1.09886e-005 A 8 = -5.38232e-007 A10 = 7.94789e-009

Various data Zoom ratio 9.51
Wide angle Medium Telephoto focal length 5.15 10.35 49.00
F number 3.61 4.50 6.00
Angle of View 32.59 20.53 4.52
Image height 3.29 3.88 3.88
Total lens length 84.96 84.96 84.96
BF 1.36 1.36 1.36

d 8 0.77 5.17 10.05
d14 10.17 5.77 0.89
d15 13.94 10.99 0.80
d20 10.84 13.78 23.97
d23 0.60 1.03 3.26
d29 3.96 3.53 1.30
d31 1.36 1.36 1.36

Entrance pupil position 11.14 14.85 21.24
Exit pupil position 93.23 159.34 63.33
Front principal point position 16.58 25.87 108.98
Rear principal point position -3.79 -8.99 -47.64

Zoom lens group data group Start surface Focal length Lens configuration length Front principal point position Rear principal point position
1 1 13.16 23.20 12.89 7.22
2 9 -6.62 3.19 0.11 -2.33
Aperture 15 ∞ 0.00 0.00 -0.00
3 16 14.47 8.23 1.83 -4.76
4 21 -8.07 1.99 0.76 -0.31
5 24 10.00 5.41 1.70 -2.01
GB 30 ∞ 1.29 0.42 -0.42

Single lens Data lens Start surface Focal length
1 1 -17.59
2 3 0.00
3 5 28.38
4 7 21.56
5 9 -8.41
6 11 -10.62
7 13 17.41
8 16 14.64
9 18 -10.07
10 19 10.07
11 21 -6.36
12 22 22.67
13 24 12.59
14 26 -12.50
15 28 9.65
16 30 0.00

1 L1 1 group
2 L2 2 groups
3 L3 3 groups
4 L4 4 groups
5 L5 5 groups
6 GB glass block
7 SP Aperture
8 IP image plane
9 PR prism
10 d d line
11g g line
12 ΔS Sagittal image plane
13 ΔM Meridional image plane
14 Fno F number
15 ω half angle of view

Claims (5)

From the object side,
It has 1 group of positive refractive power, 2 groups of negative refractive power, 3 groups of positive refractive power, and subsequent lens group,
Among the following lens groups, the most image side group has a positive refractive power,
One group has a reflective member,
When zooming, 1 group is fixed, 2 groups, 3 groups move,
The first group has a negative lens on the object side of the reflecting member,
Has two positive lenses on the image side of the reflecting member,
The most image side group has two positive lenses and one negative lens,
A zoom lens satisfying the following conditional expression:
0.2 <f1 / ft <0.4 (1)

0.15 <fa / ft <0.4 (3)
However,
f1: 1 group focal length
fa: Focal length of the most image side group
ft: focal length of the entire system at the telephoto end νai: Abbe number of the lens in the most image side group φai: power of the lens in the most image side group φw: total system power at the wide angle end 2. The zoom lens according to claim 1, wherein the following conditional expression is satisfied.

However, the power of the strongest negative lens of φn1: 1 group
vn1: Abbe number of the most powerful negative lens in 1 group
2. The zoom lens according to claim 1, wherein the following conditional expression is satisfied.
30 <vnb <50 (5)
However,
vnb: Abbe number of the most powerful negative lens in the negative group closest to the image side. 2. The zoom lens according to claim 1, wherein the following conditional expression is satisfied.
-0.3 <fb / ft <-0.1 (6)
However,
fb: The focal length of the negative group closest to the image side. In order from the object side, it consists of 1 group with positive refractive power, 2 groups with negative refractive power, 3 groups with positive refractive power, 4 groups with negative refractive power, and 5 groups with positive refractive power 2. The zoom lens according to claim 1, wherein: