JPH0749453A - Zoom lens - Google Patents

Abstract

PURPOSE:To provide a small-sized zoom lens with wide image angle which has high optical performance over the full variable power range by providing five lens groups as the whole, and properly setting the moving condition and refractive force of each lens group accompanying variable power. CONSTITUTION:A zoom lens is formed of three lens groups of first, second and third groups L1-L3 in the order from an object side, and has a front group having a positive resultant refractive power on a wide angle end and a rear group consisting of two lens groups of a fourth group L4 having positive refractive power and a fifth group L5 having negative refractive power. The first, second and third groups L1-L3 are moved so that the composed refractive force of the front group is weakened on the telescopic end, compared with the wide angle end at the variable power from the wide angle end to the telescopic end, and the fourth and fifth groups L4, L5 are moved so that the space between them is narrowed. When the focus distance of the i-th group is fi, the focus distance of the whole system in the wide angle end is fW, and the lateral magnification in the wide angle end of the i-th group is betaiW, the condition forming 0.5<1f5/fw1<1.5, 1.1<beta5W<1.7 is satisfied.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compact zoom lens having a high zoom ratio and a wide angle of view, which is suitable for a lens shutter camera, a video camera, etc. The present invention relates to a zoom lens which is excellent in portability and has a shortened distance from one lens surface to an image surface.

[0002]

2. Description of the Related Art Recently, in a lens shutter camera, a video camera, etc., a compact zoom lens having a short total lens length has been demanded as the camera becomes smaller. In particular, lens shutter cameras are becoming smaller and smaller due to the development of peripheral technologies such as zoom driving electric circuits. There is.

Conventionally, a so-called two-group zoom lens composed of two lens groups having positive and negative refracting power has been mainly used as a zoom lens for a lens shutter. Since the two-group zoom lens has a simple lens structure and a moving mechanism at the time of zooming, it has advantages such as downsizing of the camera and relatively low cost. However, since the zooming action must be performed by only one lens group, the zooming ratio is about 1.6 to 2 times, and forcing the zooming ratio to enlarge the lens system. At the same time, it becomes difficult to maintain high optical performance.

On the basis of a two-group zoom lens, the first group is divided into two lens groups having a positive refractive power, and as a whole,
A three-group zoom lens aiming at high zooming as a three-group configuration of positive and negative refracting powers is disclosed in, for example, Japanese Patent Laid-Open Nos. 3-282409, 4-37810, and 4-7651.
It is proposed in Japanese Patent No.

However, if an attempt is made to achieve a wide-angle zoom lens system having a half angle of view of 35 ° or more with this lens group configuration, the change in the entrance pupil position during zooming becomes large. For this reason, it becomes very difficult to suppress aberration variation due to zooming when achieving high zooming.

In addition to this, a zoom lens having a wide angle of view and a high zoom ratio, for example, has a half field angle at the wide-angle end of about 38 ° and a zoom ratio of about 3.5 due to the multi-lens group. Kaihei 2-
72316 and JP-A-3-249614. However, these zoom lens systems have a large front lens diameter and a large overall lens length, and are not always sufficient as photographing lenses for compact cameras.

Particularly when applied to a camera using an external viewfinder, there is a problem that the lens barrel covers the photographing field of view of the viewfinder at the wide-angle end. Further, as a result, there arises a problem that the viewfinder arrangement and the camera form are restricted.

[0008]

Generally, in a zoom lens, if the refractive power of each lens group is strengthened, the amount of movement of each lens group for obtaining a predetermined zoom ratio is reduced, and the total lens length is shortened. High zoom ratio is possible. However, if the refracting power of each lens unit is simply increased, the aberration variation due to zooming becomes large, and particularly when achieving high zooming and widening the angle of view, it is necessary to obtain good optical performance over the entire zooming range. There is a problem that it becomes difficult.

The present invention is composed of five lens groups as a whole, the moving conditions and the refractive power of each lens group during zooming are appropriately set, and the photographing angle of view at the wide angle end is about 64 to 74 °.
It is an object of the present invention to provide a zoom lens having high optical performance over the entire zoom range with a zoom ratio of about 3.5.

[0010]

A zoom lens according to the present invention comprises three lens groups, a first lens group, a second lens group, and a third lens group in order from the object side, and the combined refractive power at the wide-angle end is positive. It has a front lens group and a rear lens group consisting of two lens groups, a fourth lens group having a positive refractive power and a fifth lens group having a negative refractive power, and when zooming from the wide-angle end to the telephoto end, The second and third groups move so that the combined refractive power of the front group becomes weaker at the telephoto end than at the wide-angle end, and the fourth and fifth groups move so that their interval becomes narrower. The focal length of the group is fi, the focal length of the entire system at the wide-angle end is fW, and the lateral magnification at the wide-angle end of the i-th group is βi.
When W is set 0.5 <| f5 / fW | <1.5 (1) 1.1 <β5W <1.7・ It is characterized by satisfying the condition (2).

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1, 2 and 3 are explanatory views of paraxial refractive power arrangements of Examples 1 to 3 of a zoom lens according to the present invention. 1 to 3, (A) shows the wide-angle end and (B) shows the telephoto end. 4 to 15 are numerical examples 1 to 1 of the present invention.
12 is a lens cross-sectional view at the wide-angle end of FIG. 16 to 51 are various aberration diagrams of Numerical Examples 1 to 12 of the present invention.

In the figure, LF is a front lens group having a positive refractive power, LR is a rear lens group, SP is a diaphragm, and IP is an image plane. Li (i = 1 to 1
5) is the i-th group. The arrows indicate the direction of movement of each lens group when zooming from the wide-angle side to the telephoto side.

The front lens group LF is composed of three lens groups, a first lens group L1, a second lens group L2 and a third lens group L3, and the combined refractive power at the wide angle end is positive. The rear lens group LR includes two lens units, that is, a fourth lens unit L4 having a positive refractive power and a fifth lens unit L5 having a negative refractive power.

Upon zooming from the wide-angle end to the telephoto end, the first, second, and third lens groups move so that the combined refractive power of the front lens groups is weaker at the telephoto end than at the wide-angle end. Also, the fourth group and the fifth
The groups are moving so that their distance is narrow. At this time, the focal length of the fifth lens unit and the lateral magnification at the wide-angle end are set as in conditional expressions (1) and (2), thereby effectively achieving a predetermined zoom ratio and widening of the angle of view. We are working to reduce the size of the entire lens system.

Further, in the present invention, at the wide-angle end, the combined refractive power of the first group and the second group is negative, and the third group has a positive refractive power. Then, the fourth group is extended toward the object side to focus from an infinitely distant object to a short-distance object.

In the zoom lens of the present invention, the focal length f of the entire lens system is expressed by the following equation.

F = fA · β4 · β5 (β4> 0, β5> 0) (a) where fA is the composite focal length of the front group, and βi is the lateral magnification of the i-th group. .

In the present invention, as can be understood from the expression (a), when the magnification is changed from the wide-angle end to the telephoto end, the lateral magnifications β4 and β5 are increased, and at the same time, the composite processing distance fA of the front group is lengthened. By (weakening the composite refractive power of the front group), more efficient zooming is performed. In addition, the distance between the fourth lens unit having a positive refractive power and the fifth lens unit having a negative refractive power is made narrower (decreased) at the telephoto end than at the wide-angle end to give a zooming effect to the fifth lens unit. This makes it easy to achieve high zoom ratio.

Particularly, in the present invention, by adopting the paraxial refractive power arrangement as shown in FIGS. 1 to 3, the photographing angle of view is widened so that the focal length at the wide angle end becomes smaller than the diagonal length of the screen. ing.

Specifically, in the first embodiment of FIG. 1, the front group consists of a first group having a negative refractive power, a second group having a positive refractive power, and a third group having a positive refractive power. At the time of zooming to the telephoto end, each lens group is moved so that the distance between the first and second groups decreases and the distance between the second and third groups increases.

In the second embodiment of FIG. 2, the front group consists of a first group of negative refracting power, a second group of negative refracting power, and a third group of positive refracting power, from the wide-angle end to the telephoto end. At the time of zooming, each lens group is moved so that the distance between the first and second groups increases and the distance between the second and third groups decreases.

In the third embodiment of FIG. 3, the front group consists of a first group having a positive refractive power, a second group having a negative refractive power, and a third group having a positive refractive power, from the wide-angle end to the telephoto end. At the time of zooming, each lens group is moved so that the distance between the first and second groups increases and the distance between the second and third groups decreases.

In Embodiments 1 to 3 of FIGS. 1 to 3, the first group and the third group are integrally moved to simplify the mechanism, but as shown in Numerical Example 12 described later. You may move them independently. According to this, the degree of freedom in design can be increased.

In the present invention, in the above lens structure, by satisfying the conditional expressions (1) and (2), the overall size of the lens system is reduced, and high optical performance is obtained over the entire zoom range. .

Next, the technical meanings of the above conditional expressions will be described.

Conditional expression (1) relates to the negative refracting power of the fifth lens group, and is mainly for effectively changing the magnification. If the negative refractive power of the fifth lens unit becomes weaker than the upper limit value of the conditional expression (1), the zooming effect of the lens unit becomes weak at the time of zooming, so that a constant zoom ratio is obtained. Therefore, the amount of movement of each lens group must be increased, which increases the total lens length.

If the lower limit of conditional expression (1) is exceeded, at the wide-angle end, the lens system has positive composite refractive power of the first to fourth groups and negative refractive power of the fifth group. The action as a telephoto type becomes too strong.

As a result, the back focus of the lens system becomes too short, which leads to an increase in the lens outer diameter of the fifth lens unit in order to secure a constant amount of peripheral light, and at the same time, the refractive power of the lens unit is strong. Since it becomes too much, high-order field curvature and astigmatism occur, which makes it difficult to correct them.

Conditional expression (2) relates to the lateral magnification at the wide-angle end of the fifth lens unit.

Now, when the back focus of the lens system at the wide-angle end is BfW, it can be expressed as BfW = f5 (1-β5W).

Therefore, in the present invention, the total length of the lens system and various aberrations are corrected in a well-balanced manner by appropriately setting the values of conditional expression (2) as well as conditional expression (1).

If the upper limit of conditional expression (2) is exceeded, the back focus is unnecessarily extended and the overall lens length is increased, which is not suitable for achieving compactness. On the other hand, if the value goes below the lower limit, it becomes difficult to maintain the back focus at a positive value, which imposes an unreasonable amount on the shape and arrangement of the fifth lens unit and makes it impossible to satisfactorily correct various aberrations.

In the present invention, it is preferable to configure each lens group as follows in order to widen the angle of view while reducing the variation of aberration due to zooming and to secure high optical performance over the entire screen.

(1) The numerical conditions of the conditional expressions (1) and (2) described above are further defined as 0.45 <f5. (1-β5W) / fW <0.2 (3) Good to set. If the upper limit value or the lower limit value is exceeded in the conditional expression (3), the compactness of the lens system and the optical performance cannot be balanced, which is not preferable.

(2) Considering the zoom lens of the present invention as a zoom lens having a front group and a rear group as a two-group configuration, the combined refractive power φ12 and the combined focal length f12 of the front lens system are expressed by the following equations.

Φ12 = 1 / f12 = φ1 + φ2-φ1 · φ2 · e (b) where φi is the refracting power of the i-th group, and e is the principal point spacing between the first and second groups. Is. From the equation (b), when the front lens group and the rear lens group have a certain degree of positive refractive power at the wide-angle end, the principal point interval e may be reduced in order to shorten the focal length f12. However, there is a limit to making the principal point distance e as small as possible because interference occurs between the lens surfaces of the front group and the rear group.

Therefore, in the present invention, at the wide-angle end, the combined refractive power of the first group and the second group in the front group is made negative, and, following these lens groups, the third group having a positive refractive power with a certain distance. Has a lens configuration. As a result, the front group takes the form of retro focus type as a whole,
Thereby, the rear principal point of the front group is arranged on the image plane side. As a result, while reducing the principal point distance e,
The lens system has a wide angle of view while preventing the interference between the lens surfaces.

Further, the front group is a retrofocus type,
By arranging the entrance pupil position on the image plane side so that the entire lens system approaches a symmetrical type, aberrations are well corrected in a wide angle range. Since the third and fourth groups each have a positive refracting power, according to the equation (b), when the magnification is changed from the wide-angle end to the telephoto end, each lens group is moved so as to be separated from each other. This increases the variable power efficiency.

Further, if a high-magnification and compact optical system is desired, it is preferable that each lens group in the front group moves toward the object side at the wide-angle end and at the telephoto end. Thereby, while preventing the interference of each lens group in the front group, the front group,
It is possible to efficiently change the magnification in the rear group.

(3) When the composite refractive power of the front group at the wide-angle end is _φ123W , 0.2 <fW · _φ123W <1.0 (4) 0.6 <f3 / It is preferable that the condition of FW <2.2 (5) is satisfied.

Conditional expression (4) relates to the refractive power of the front lens group. When the upper limit of conditional expression (4) is exceeded, the refractive power of the front lens group becomes too strong at the wide-angle end, and the action of the telephoto system becomes strong. At the same time, it becomes difficult to obtain the back focus, and spherical aberration occurs in the front group in a large amount in the under direction, and it becomes difficult to correct this with other lens groups.
When the value goes below the lower limit, the total lens length increases, and at the same time, the positive refractive power of the rear lens group must be strengthened to maintain the focal length at the wide-angle end. Difficult to take.

Conditional expression (5) relates to the positive refracting power of the third lens unit.
Since the refracting power of the group becomes weak, the amount of movement of the lens group at the time of zooming increases, leading to an increase in the lens system. On the other hand, when the value goes below the lower limit, high-order spherical aberration is strongly generated in the third lens group, which makes it difficult to correct it.

In the present invention, the upper and lower limits of the above conditional expressions (4) and (5) are set in order to satisfactorily correct the optical performance while shortening the total lens length particularly at the wide-angle end. It is better to set as follows.

0.35 <fW · φ _123W <0.85 (4a) 0.8 <f3 / fW <1.9 (5a) Becomes

(4) When the focal length of the i-th group is fi and the lateral magnification of the i-th group at the wide-angle end is βiW, 0.8 <f4 / fW <1.6 ... ( 6) It is preferable that the condition of 0.25 <β4W <0.65 (7) is satisfied.

Conditional expression (6) relates to the refractive power of the fourth lens unit at the wide-angle end. When the upper limit of conditional expression (6) is exceeded and the refractive power of the fourth lens unit becomes weaker, a constant focal length at the wide-angle end is obtained. Therefore, when the refractive power of the negative lens group is weakened, the lens system increases. Further, if the refractive power of the positive lens group in the front group is strengthened, high-order spherical aberration occurs at the telephoto end, and it becomes difficult to correct this. On the other hand, if the lower limit is exceeded and the refractive power of the fourth lens unit becomes too strong, the telephoto type action of the fourth and fifth lens units becomes too strong, making it difficult to obtain a back focus. Many aberrations occur, and it becomes difficult to correct them with other lens groups.

Conditional expression (7) relates to the lateral magnification of the fourth lens unit at the wide-angle end. If the upper limit of conditional expression (7) is exceeded, it becomes difficult to obtain back focus at the wide-angle end, resulting in an increase in the lens outer diameter of the fourth lens unit. On the other hand, when the value goes below the lower limit, the refractive power of the other lens units becomes strong in order to obtain a constant focal length, so that it becomes difficult to correct aberration variation during zooming.

(5) The fourth lens unit having a positive refractive power is at least 1
It has a positive lens and a negative lens one by one, of which the lens surface closest to the object side has a concave surface facing the object side, and the lens surface closest to the image surface has a convex surface facing the image surface side. Is good. Moreover, if an aspherical surface is introduced into the lens surface closest to the image surface,
It is possible to easily correct the aberration variation due to zooming and the aberration correction of the entire screen.

(6) The fifth lens unit having a negative refractive power has at least 1
When the average values of the Abbe numbers of the materials of the positive lens and the negative lens in the fifth lens group are respectively ν5P and ν5N, each having a negative lens and a positive lens with a concave surface facing the object side, 12 <ν5N It is better to satisfy the condition of −ν5P <35 (8). If the value exceeds the upper limit value or the lower limit value of the conditional expression (8), a large amount of chromatic aberration variation occurs during zooming, and it becomes difficult to correct this with other lens groups.

(7) The diaphragm is arranged in the air space existing between the lens surface of the third lens unit closest to the image plane to the lens surface of the fourth lens unit closest to the image plane, and the entrance pupil is located at an appropriate position. It is preferable because it can be disposed in the optical disk and the variation in aberration due to zooming can be suppressed. The diaphragm may be moved independently of the other lens groups during zooming, or may be moved integrally with the other lens groups. This makes it possible to dispose the diaphragm position in the vicinity of the position of the entrance pupil that moves during zooming, which is advantageous in preventing changes in field curvature aberration when the diaphragm is small.

When focusing is performed by the fourth lens unit, when the fourth lens unit includes an aperture stop, moving the focus lens unit with the aperture stop fixed on the optical axis is a drive for moving the aperture stop mechanism during focusing. It is preferable because the torque can be reduced.

(8) If the fourth group is divided into two or more lens groups and the distance between the lens groups is changed during zooming or during focusing, variation in aberration during zooming and focusing is reduced. It is preferable because it can be

(9) In the focus of the present invention, the fourth group is moved to the object side to focus from an object at infinity to a short-distance object, but it is also possible to move other lens groups. . For example, a method of moving the front group to the object side may be used.

If the back focus is sufficient at the wide-angle end, the fifth lens unit may be moved to the image plane side. In this case, it is effective to reduce the lens outer diameter of the first lens unit. Becomes It is also possible to simultaneously move two or more lens groups in the first to fifth groups.

Next, numerical examples of the present invention will be shown. In the numerical examples, 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 and air gap from the object side, and Ni and νi are respectively from the object side in the i-th lens. The refractive index of glass and the Abbe number.

Table 1 shows the relationship between the above-mentioned conditional expressions and various numerical values in the numerical examples.

The aspherical shape has an X axis in the optical axis direction, an H axis in a direction perpendicular to the optical axis, a positive light traveling direction, and R as a paraxial radius of curvature,
When A, B, C, D and E are aspherical coefficients,

[0058]

[Equation 1] It is expressed by

Numerical Example 1 F = 28.84 to 101.48 fNO = 1: 3.6 to 8.2 2ω = 73.8 ° to 24.1 ° R 1 = -107.63 D 1 = 1.30 N 1 = 1.80400 ν 1 = 46.6 R 2 = 29.11 D 2 = 3.50 N 2 = 1.80518 ν 2 = 25.4 R 3 = 188.37 D 3 = 0.38 R 4 = 248.08 D 4 = 1.10 N 3 = 1.60342 ν 3 = 38.0 R 5 = 33.55 D 5 = variable R 6 = 33.40 D 6 = 1.00 N 4 = 1.84666 ν 4 = 23.8 R 7 = 19.67 D 7 = 2.70 N 5 = 1.48749 ν 5 = 70.2 R 8 = -176.19 D 8 = Variable R 9 = 29.75 D 9 = 2.80 N 6 = 1.56873 ν 6 = 63.2 R10 = -53.64 D10 = Variable R11 = -19.54 D11 = 0.87 N 7 = 1.64769 ν 7 = 33.8 R12 = -93.56 D12 = 1.00 R13 = ∞ (Aperture) D13 = 1.00 R14 = -57.06 D14 = 0.78 N 8 = 1.48749 ν 8 = 70.2 R15 = 36.54 D15 = 2.10 N 9 = 1.84666 ν 9 = 23.8 R16 = -45.52 D16 = 4.85 R17 = 34.65 D17 = 1.10 N10 = 1.84666 ν10 = 23.8 R18 = 12.82 D18 = 5.50 N11 = 1.58313 ν11 = 59.4 R19 = -23.25 D19 = Variable R20 = -33.52 D20 = 3.00 N12 = 1.84666 ν12 = 23.8 R21 = -17.94 D21 = 0.15 R22 = -20.79 D22 = 1.30 N13 = 1.83481 ν13 = 42.7 R23 = -171.17 D23 = 4.39 R24 = -17.91 D24 = 1.50 N14 = 1.78590 ν14 = 44.2 R25 = -73.32 Aspheric coefficient R19 K = -3.37 × 10 ^-1 A = 0 B = 1.15 × 10 ^-5 C = -2.60 × 10 ^-8 D = -2.60 × 10 ^-10 E = 0

[0060]

[Table 1] (Numerical Example 2) F = 29.25 to 101.00 fNO = 1: 3.6 to 8.2 2ω = 73.0 ° to 24.2 ° R 1 = -136.48 D 1 = 1.30 N 1 = 1.80400 ν 1 = 46.6 R 2 = 44.39 D 2 = 0.41 R 3 = 53.68 D 3 = 3.00 N 2 = 1.80518 ν 2 = 25.4 R 4 = -226.68 D 4 = 1.10 N 3 = 1.66998 ν 3 = 39.3 R 5 = 35.15 D 5 = variable R 6 = 36.05 D 6 = 1.00 N 4 = 1.84666 ν 4 = 23.8 R 7 = 22.91 D 7 = 2.70 N 5 = 1.48749 ν 5 = 70.2 R 8 = -148.68 D 8 = Variable R 9 = 29.98 D 9 = 2.80 N 6 = 1.56873 ν 6 = 63.2 R10 = -61.97 D10 = Variable R11 = -20.25 D11 = 0.87 N 7 = 1.64769 ν 7 = 33.8 R12 = -96.09 D12 = 1.00 R13 = ∞ (Aperture) D13 = 1.00 R14 = -49.89 D14 = 0.78 N 8 = 1.48749 ν 8 = 70.2 R15 = 41.40 D15 = 2.10 N 9 = 1.84666 ν 9 = 23.8 R16 = -42.55 D16 = 5.60 R17 = 31.32 D17 = 1.10 N10 = 1.84666 ν10 = 23.8 R18 = 12.25 D18 = 5.50 N11 = 1.58313 ν11 = 59.4 R19 = -25.47 D19 = Variable R20 = -31.70 D20 = 3.50 N12 = 1.84666 ν12 = 23.8 R21 = -17.94 D21 = 0.20 R22 = -22.10 D22 = 1.30 N13 = 1.80610 ν13 = 41.0 R23 = -317.84 D23 = 4.89 R24 = -18.10 D24 = 1.50 N14 = 1.78590 ν14 = 44.2 R25 = -63.65 Aspheric coefficient R19 K = -1.81 × 10 ^-1 A = 0 B = 8.60 × 10 ^-6 C = 9.07 × 10 ^-8 D = -1.91 × 10 ^-9 E = 0

[0061]

[Table 2] (Numerical Example 3) F = 35.00 to 110.00 fNO = 1: 3.7 to 8.2 2ω = 63.4 ° to 22.3 ° R 1 = -112.16 D 1 = 1.30 N 1 = 1.80400 ν 1 = 46.6 R 2 = 139.61 D 2 = 0.41 R 3 = 163.84 D 3 = 3.00 N 2 = 1.80518 ν 2 = 25.4 R 4 = -107.84 D 4 = 1.10 N 3 = 1.66998 ν 3 = 39.3 R 5 = 76.56 D 5 = variable R 6 = 36.05 D 6 = 1.00 N 4 = 1.84666 ν 4 = 23.8 R 7 = 25.55 D 7 = 3.80 N 5 = 1.48749 ν 5 = 70.2 R 8 = -389.95 D 8 = Variable R 9 = 45.54 D 9 = 3.20 N 6 = 1.56873 ν 6 = 63.2 R10 = -160.77 D10 = Variable R11 = ∞ (Aperture) D11 = 1.30 R12 = -20.88 D12 = 0.87 N 7 = 1.64769 ν 7 = 33.8 R13 = -233.98 D13 = 2.00 R14 = -159.29 D14 = 0.78 N 8 = 1.48749 ν 8 = 70.2 R15 = 46.64 D15 = 2.10 N 9 = 1.84666 ν 9 = 23.8 R16 = -49.54 D16 = 5.60 R17 = 35.02 D17 = 1.10 N10 = 1.84666 ν10 = 23.8 R18 = 14.70 D18 = 5.50 N11 = 1.58313 ν11 = 59.4 R19 = -28.48 D19 = Variable R20 = -19.90 D20 = 3.50 N12 = 1.84666 ν12 = 23.8 R21 = -17.24 D21 = 4.50 R22 = -16.95 D22 = 1.50 N13 = 1.77250 ν13 = 49.6 R23 = 483.96 Aspherical coefficient R19 K = 8.88 × 10 ^-1 A = 0 B = 1.21 × 10 ^-5 C = 1.06 × 10 ^-7 D = -1.47 × 10 ^-9 E = 0 Aspheric coefficient R22 K = 0 A = 0 B = 8.13 × 10 ^-6 C = 2.25 × 10 ^-8 D = -1.09 × 10 ^-11 E = 0

[0062]

[Table 3] (Numerical Example 4) F = 35.00 to 110.12 fNO = 1: 3.7 to 8.2 2ω = 63.4 ° to 22.2 ° R 1 = -209.03 D 1 = 1.30 N 1 = 1.80400 ν 1 = 46.6 R 2 = 127.91 D 2 = 0.41 R 3 = 143.81 D 3 = 3.00 N 2 = 1.80518 ν 2 = 25.4 R 4 = -90.07 D 4 = 1.10 N 3 = 1.66998 ν 3 = 39.3 R 5 = 50.47 D 5 = variable R 6 = 36.53 D 6 = 1.00 N 4 = 1.84666 ν 4 = 23.8 R 7 = 25.31 D 7 = 3.80 N 5 = 1.48749 ν 5 = 70.2 R 8 = -1105.62 D 8 = Variable R 9 = 36.04 D 9 = 3.20 N 6 = 1.56873 ν 6 = 63.2 R10 = -160.41 D10 = Variable R11 = ∞ (Aperture) D11 = 1.30 R12 = -21.36 D12 = 0.87 N 7 = 1.64769 ν 7 = 33.8 R13 = -289.38 D13 = 2.00 R14 = -78.97 D14 = 0.78 N 8 = 1.48749 ν 8 = 70.2 R15 = 46.97 D15 = 2.10 N 9 = 1.84666 ν 9 = 23.8 R16 = -48.67 D16 = 5.60 R17 = 32.95 D17 = 1.10 N10 = 1.84666 ν10 = 23.8 R18 = 14.36 D18 = 5.50 N11 = 1.58313 ν11 = 59.4 R19 = -27.03 D19 = Variable R20 = -30.81 D20 = 3.50 N12 = 1.84666 ν12 = 23.8 R21 = -19.27 D21 = 0.20 R22 = -30.53 D22 = 1.30 N13 = 1.80610 ν13 = 41.0 R23 = -115.65 D23 = 4.89 R24 = -18.03 D24 = 1.50 N14 = 1.78590 ν14 = 44.2 R25 = -118.71 aspheric coefficients ^{R19 K = 3.77 × 10 -1 A} = 0 B = 1.57 ^{10 -5 C = 3.17 × 10 -8} D = -8.36 × 10 -10 E = 0

[0063]

[Table 4] (Numerical Example 5) F = 28.84 to 89.41 fNO = 1: 3.8 to 8.2 2ω = 73.8 ° to 27.2 ° R 1 = -217.48 D 1 = 2.00 N 1 = 1.80518 ν 1 = 25.4 R 2 = -103.00 D 2 = 1.20 N 2 = 1.69680 ν 2 = 55.5 R 3 = 48.69 D 3 = Variable R 4 = 154.19 D 4 = 1.30 N 3 = 1.65844 ν 3 = 50.9 R 5 = 37.47 D 5 = Variable R 6 = 29.87 D 6 = 1.00 N 4 = 1.84666 ν 4 = 23.8 R 7 = 23.19 D 7 = 2.90 N 5 = 1.48749 ν 5 = 70.2 R 8 = -101.43 D 8 = 0.30 R 9 = 33.35 D 9 = 2.30 N 6 = 1.60311 ν 6 = 60.7 R10 = -173.29 D10 = Variable R11 = -17.33 D11 = 0.87 N 7 = 1.64769 ν 7 = 33.8 R12 = -64.01 D12 = 1.00 R13 = ∞ (Aperture) D13 = 1.00 R14 = -1012.52 D14 = 0.70 N 8 = 1.48749 ν 8 = 70.2 R15 = 39.15 D15 = 1.80 N 9 = 1.84666 ν 9 = 23.8 R16 = -37.96 D16 = 5.17 R17 = 40.91 D17 = 1.10 N10 = 1.84666 ν10 = 23.8 R18 = 11.63 D18 = 5.60 N11 = 1.58313 ν11 = 59.4 R19 = -23.69 D19 = Variable R20 = -29.78 D20 = 3.60 N12 = 1.84666 ν12 = 23.8 R21 = -18.07 D21 = 0.20 R22 = -22.10 D22 = 1.30 N13 = 1.74320 ν13 = 49.3 R23 = 634.28 D23 = 4.38 R24 = -22.75 D24 = 1.50 N14 = 1.72916 ν14 = 54.7 R25 = -113.54 Aspheric coefficient R19 K = -1.96 × 10 ^-1 A = 0 B = 1.09 × 1 0 ^-5 C = 8.05 × 10 ^-8 D = -2.53 × 10 ^-9 E = 0

[0064]

[Table 5] (Numerical Example 6) F = 30.43 to 100.00 fNO = 1: 3.7 to 8.2 2ω = 70.8 ° to 24.4 ° R 1 = -677.46 D 1 = 2.00 N 1 = 1.80518 ν 1 = 25.4 R 2 = -69.17 D 2 = 1.20 N 2 = 1.69680 ν 2 = 55.5 R 3 = 63.43 D 3 = Variable R 4 = 3704.92 D 4 = 1.30 N 3 = 1.65844 ν 3 = 50.9 R 5 = 45.60 D 5 = Variable R 6 = 32.60 D 6 = 1.00 N 4 = 1.84666 ν 4 = 23.8 R 7 = 22.08 D 7 = 3.20 N 5 = 1.48749 ν 5 = 70.2 R 8 = -224.31 D 8 = 0.30 R 9 = 36.51 D 9 = 2.70 N 6 = 1.60311 ν 6 = 60.7 R10 = -122.67 D10 = Variable R11 = ∞ (Aperture) D11 = Variable R12 = -17.93 D12 = 0.87 N 7 = 1.64769 ν 7 = 33.8 R13 = -71.56 D13 = 2.00 R14 = -228.00 D14 = 0.70 N 8 = 1.48749 ν 8 = 70.2 R15 = 44.17 D15 = 1.80 N 9 = 1.84666 ν 9 = 23.8 R16 = -46.21 D16 = 5.17 R17 = 39.16 D17 = 1.10 N10 = 1.84666 ν10 = 23.8 R18 = 13.54 D18 = 5.60 N11 = 1.58313 ν11 = 59.4 R19 = -22.09 D19 = Variable R20 = -36.36 D20 = 3.60 N12 = 1.84666 ν12 = 23.8 R21 = -18.73 D21 = 0.20 R22 = -22.97 D22 = 1.30 N13 = 1.78590 ν13 = 44.2 R23 = -161.56 D23 = 4.50 R24 = -18.57 D24 = 1.50 N14 = 1.72916 ν14 = 54.7 R25 = -232.78 Aspheric coefficient R19 K = -3.97 × 10 ^-1 A = 0 B = 1.18 × 10 ^-5 C = 7.44 × 10 ^-8 D = -1.47 × 10 ^-9 E = 0

[0065]

[Table 6] (Numerical Example 7) F = 30.00 to 100.00 fNO = 1: 3.6 to 8.2 2ω = 71.6 ° to 24.4 ° R 1 = -228.47 D 1 = 2.00 N 1 = 1.80518 ν 1 = 25.4 R 2 = -61.62 D 2 = 1.20 N 2 = 1.69680 ν 2 = 55.5 R 3 = 60.27 D 3 = Variable R 4 = 300.46 D 4 = 1.30 N 3 = 1.65844 ν 3 = 50.9 R 5 = 47.91 D 5 = Variable R 6 = 32.90 D 6 = 1.00 N 4 = 1.84666 ν 4 = 23.8 R 7 = 22.76 D 7 = 3.20 N 5 = 1.48749 ν 5 = 70.2 R 8 = -264.26 D 8 = 0.30 R 9 = 34.66 D 9 = 2.50 N 6 = 1.60311 ν 6 = 60.7 R10 = -148.49 D10 = Variable R11 = ∞ (Aperture) D11 = 1.70 R12 = -18.05 D12 = 0.87 N 7 = 1.64769 ν 7 = 33.8 R13 = -63.03 D13 = 2.00 R14 = -167.30 D14 = 0.70 N 8 = 1.48749 ν 8 = 70.2 R15 = 46.92 D15 = 1.80 N 9 = 1.84666 ν 9 = 23.8 R16 = -49.81 D16 = 5.17 R17 = 36.08 D17 = 1.10 N10 = 1.84666 ν10 = 23.8 R18 = 14.30 D18 = 5.60 N11 = 1.58313 ν11 = 59.4 R19 = -24.31 D19 = variable R20 = -19.49 D20 = 3.60 N12 = 1.84666 ν12 = 23.8 R21 = -16.47 D21 = 4.50 R22 = -16.05 D22 = 1.50 N13 = 1.77250 ν13 = 49.6 R23 = 185.92 aspheric coefficients R19 K = -6.76 × 10 ^{- 1} A = 0 B = 1.7138 × 10 ^-8 C = 7.38 × 10 ^-8 D = -1.15 × 10 ^-9 E = 0 Aspheric coefficient R22 K = 0 A = 0 B = 1.69 × 10 ^-5 C = 3.53 × 10 ^-8 D = -1.80 × 10 ^-8 E = 0

[0066]

[Table 7] (Numerical Example 8) F = 35.00 to 115.28 fNO = 1: 3.9 to 7.9 2ω = 63.4 ° to 21.3 ° R 1 = -118.09 D 1 = 3.00 N 1 = 1.48749 ν 1 = 70.2 R 2 = -60.06 D 2 = Variable R 3 = -58.51 D 3 = 2.40 N 2 = 1.74077 ν 2 = 27.8 R 4 = -61.41 D 4 = 1.50 N 3 = 1.60311 ν 3 = 60.7 R 5 = 38.15 D 5 = Variable R 6 = 34.34 D 6 = 1.20 N 4 = 1.84666 ν 4 = 23.8 R 7 = 27.04 D 7 = 3.20 N 5 = 1.48749 ν 5 = 70.2 R 8 = -319.69 D 8 = 0.15 R 9 = 45.60 D 9 = 2.80 N 6 = 1.65160 ν 6 = 58.5 R10 = -166.18 D10 = Variable R11 = -20.70 D11 = 1.00 N 7 = 1.64769 ν 7 = 33.8 R12 = -62.94 D12 = 1.10 R13 = ∞ (Aperture) D13 = 1.10 R14 = 6539.41 D14 = 0.85 N 8 = 1.48749 ν 8 = 70.2 R15 = 48.84 D15 = 2.18 N 9 = 1.84666 ν 9 = 23.8 R16 = -45.73 D16 = 6.59 R17 = 51.35 D17 = 1.10 N10 = 1.84666 ν10 = 23.8 R18 = 13.56 D18 = 6.00 N11 = 1.58313 ν11 = 59.4 R19 =- 31.86 D19 = Variable R20 = -39.44 D20 = 3.80 N12 = 1.84666 ν12 = 23.8 R21 = -20.59 D21 = 0.15 R22 = -26.82 D22 = 1.40 N13 = 1.74320 ν13 = 49.3 R23 = -184.23 D23 = 3.83 R24 = -25.14 D24 = 1.60 N14 = 1.72000 ν14 = 50.3 R25 = 3454.63 aspheric coefficients ^{R19 K = -1.96 × 10 -1 A} = 0 B = 5.69 ^{10 -6 C = 2.67 × 10 -8} D = -6.80 × 10 -10 E = 0

[0067]

[Table 8] (Numerical Example 9) F = 35.0 to 106.00 fNO = 1: 3.9 to 7.6 2 ω = 63.4 ° to 23.1 ° R 1 = -79.23 D 1 = 2.50 N 1 = 1.48749 ν 1 = 70.2 R 2 = -53.54 D 2 = Variable R 3 = -62.78 D 3 = 2.00 N 2 = 1.76182 ν 2 = 26.5 R 4 = -39.42 D 4 = 1.30 N 3 = 1.63854 ν 3 = 55.4 R 5 = 36.74 D 5 = Variable R 6 = 30.48 D 6 = 1.00 N 4 = 1.84666 ν 4 = 23.8 R 7 = 22.22 D 7 = 3.80 N 5 = 1.48749 ν 5 = 70.2 R 8 = -240.21 D 8 = 0.30 R 9 = 36.74 D 9 = 2.80 N 6 = 1.60311 ν 6 = 60.7 R10 = -166.62 D10 = Variable R11 = -18.91 D11 = 0.87 N 7 = 1.64769 ν 7 = 33.8 R12 = -123.06 D12 = 1.00 R13 = ∞ (Aperture) D13 = 1.00 R14 = -156.26 D14 = 0.70 N 8 = 1.48749 ν 8 = 70.2 R15 = 42.83 D15 = 1.80 N 9 = 1.84666 ν 9 = 23.8 R16 = -36.50 D16 = 4.97 R17 = 46.04 D17 = 1.10 N10 = 1.84666 ν10 = 23.8 R18 = 13.31 D18 = 5.90 N11 = 1.58313 ν11 = 59.4 R19 = -27.43 D19 = Variable R20 = -33.93 D20 = 3.20 N12 = 1.84666 ν12 = 23.8 R21 = -19.80 D21 = 0.20 R22 = -23.32 D22 = 1.30 N13 = 1.74320 ν13 = 49.3 R23 = -249.42 D23 = 3.90 R24 = -24.35 D24 = 1.50 N14 = 1.72000 ν14 = 50.3 R25 = -128.73 Aspheric coefficient R19 K = 5.69 × 10 ^-1 A = 0 B = 1.26 × 10 ^-5 C = 1.04 × 10 ^-9 D = -1.93 × 10 ^-9 E = 0

[0068]

[Table 9] (Numerical Example 10) F = 30.00 to 100.01 fNO = 1: 3.8 to 8.2 2ω = 71.6 ° to 24.4 ° R 1 = -75.51 D 1 = 2.50 N 1 = 1.48749 ν 1 = 70.2 R 2 = -60.06 D 2 = Variable R 3 = -86.13 D 3 = 2.00 N 2 = 1.76182 ν 2 = 26.5 R 4 = -46.48 D 4 = 1.30 N 3 = 1.63854 ν 3 = 55.4 R 5 = 37.68 D 5 = Variable R 6 = 28.74 D 6 = 1.00 N 4 = 1.84666 ν 4 = 23.8 R 7 = 20.87 D 7 = 3.80 N 5 = 1.48749 ν 5 = 70.2 R 8 = -2684.27 D 8 = 0.30 R 9 = 36.29 D 9 = 2.80 N 6 = 1.60311 ν 6 = 60.7 R10 = -217.74 D10 = Variable R11 = ∞ (Aperture) D11 = 1.50 R12 = -18.69 D12 = 0.87 N 7 = 1.64769 ν 7 = 33.8 R13 = -126.83 D13 = 2.00 R14 = -485.52 D14 = 0.70 N 8 = 1.48749 ν 8 = 70.2 R15 = 45.24 D15 = 1.80 N 9 = 1.84666 ν 9 = 23.8 R16 = -40.48 D16 = 4.97 R17 = 40.96 D17 = 1.10 N10 = 1.84666 ν10 = 23.8 R18 = 13.82 D18 = 5.90 N11 = 1.58313 ν11 = 59.4 R19 = -23.92 D19 = Variable R20 = -31.77 D20 = 3.20 N12 = 1.84666 ν12 = 23.8 R21 = -19.52 D21 = 0.20 R22 = -23.46 D22 = 1.30 N13 = 1.74320 ν13 = 49.3 R23 = -245.47 D23 = 3.90 R24 = -23.35 D24 = 1.50 N14 = 1.72000 ν14 = 50.3 R25 = -226.34 Aspheric coefficient R19 K = 2.79 A = 0 B = 4.36 × 10 ^-5 C = 3.06 × 10 ^-8 D = 7.74 × 10 ^-10 E = 0

[0069]

[Table 10] (Numerical Example 11) F = 30.00 to 100.00 fNO = 1: 3.7 to 8.2 2ω = 71.6 ° to 24.4 ° R 1 = -156.75 D 1 = 2.50 N 1 = 1.48749 ν 1 = 70.2 R 2 = -61.45 D 2 = Variable R 3 = -76.43 D 3 = 2.00 N 2 = 1.76182 ν 2 = 26.5 R 4 = -43.96 D 4 = 1.30 N 3 = 1.63854 ν 3 = 55.4 R 5 = 36.02 D 5 = Variable R 6 = 28.46 D 6 = 1.00 N 4 = 1.84666 ν 4 = 23.8 R 7 = 20.87 D 7 = 2.80 N 5 = 1.48749 ν 5 = 70.2 R 8 = 2361.46 D 8 = 0.30 R 9 = 34.03 D 9 = 2.00 N 6 = 1.60311 ν 6 = 60.7 R10 = 699.53 D10 = Variable R11 = ∞ (Aperture) D11 = 1.50 R12 = -17.52 D12 = 0.87 N 7 = 1.64769 ν 7 = 33.8 R13 = -114.73 D13 = 2.00 R14 = -358.48 D14 = 0.70 N 8 = 1.48749 ν 8 = 70.2 R15 = 50.31 D15 = 1.80 N 9 = 1.84666 ν 9 = 23.8 R16 = -38.06 D16 = 4.97 R17 = 37.70 D17 = 1.10 N10 = 1.84666 ν10 = 23.8 R18 = 14.09 D18 = 5.90 N11 = 1.58313 ν11 = 59.4 R19 = -23.75 D19 = Variable R20 = -20.64 D20 = 3.20 N12 = 1.84666 ν12 = 23.8 R21 = -17.20 D21 = 4.00 R22 = -16.56 D22 = 1.70 N13 = 1.77250 ν13 = 49.6 R23 = 253.94 Aspherical coefficient R19 K = 3.13 × 10 ^-1 A = 0 B = 4.79 × 10 ^-5 C = 2.18 × 10 ^-7 D = 1.05 × 10 ^-10 E = 0 Aspheric coefficient R22 K = 0 A = 0 B = 1.69 × 10 ^-5 C = 7.54 × 10 ^-8 D = -9.87 × 10 ^-11 E = 0

[0070]

[Table 11] (Numerical Example 12) F = 28.85 to 101.00 fNO = 1: 3.3 to 9.0 2 ω = 73.7 ° to 24.2 ° R 1 = 424.11 D 1 = 2.40 N 1 = 1.51633 ν 1 = 64.2 R 2 = -60.06 D 2 = variable R 3 = -38.54 D 3 = 1.20 N 2 = 1.80400 ν 2 = 46.6 R 4 = 19.56 D 4 = 1.35 R 5 = 21.49 D 5 = 2.90 N 3 = 1.84666 ν 3 = 23.8 R 6 = 176.01 D 6 = Variable R 7 = 15.65 D 7 = 0.90 N 4 = 1.84666 ν 4 = 23.8 R 8 = 11.27 D 8 = 4.50 N 5 = 1.48749 ν 5 = 70.2 R 9 = -21.44 D 9 = 0.90 N 6 = 1.84666 ν 6 = 23.8 R10 = -29.88 D10 = Variable R11 = ∞ (Aperture) D11 = 3.00 R12 = -24.67 D12 = 2.55 N 7 = 1.80518 ν 7 = 25.4 R13 = -47.29 D13 = 0.50 R14 = -36.54 D14 = 1.00 N 8 = 1.65160 ν 8 = 58.5 R15 = 155.75 D15 = 5.80 N 9 = 1.77250 ν 9 = 49.6 R16 = -14.23 D16 = variable R17 = -28.76 D17 = 2.30 N10 = 1.84666 ν10 = 23.8 R18 = -20.20 D18 = 0.30 R19 = -25.76 D19 = 1.30 N11 = 1.69680 ν11 = 55.5 R20 = -80.69 D20 = 3.51 R21 = -18.83 D21 = 1.50 N12 = 1.77250 ν12 = 49.6 R22 = 431.90 Aspheric coefficient R12 K = 4.96 A = 0 B = -6.07 × 10 ^-5 C = 3.60 × 10 ^-7 D = 3.33 × 10 ^-9 E = 0 Aspheric coefficient R16 K = -2.66 A = 0 B = -1.12 × 10 ^-4 C = 1.63 × 10 ^-7 D = -1.37 × 1 0 ^-9 E = 0

[0071]

[Table 12]

[0072]

As described above, according to the present invention, as a whole, it is composed of five lens groups, and by appropriately setting the moving conditions and the refractive power of each lens group during zooming, photographing at the wide-angle end is possible. It is possible to achieve a zoom lens having a high optical performance over the entire zoom range with an angle of view of about 64 to 74 degrees and a zoom ratio of about 3.5.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a paraxial refractive power arrangement of Example 1 of the zoom lens of the present invention.

FIG. 2 is an explanatory diagram of a paraxial refractive power arrangement according to a second embodiment of the zoom lens of the present invention.

FIG. 3 is an explanatory diagram of a paraxial refractive power arrangement of Example 3 of the zoom lens of the present invention.

FIG. 4 is a lens cross-sectional view at a wide-angle end according to Numerical Example 1 of the present invention.

FIG. 5 is a lens cross-sectional view at a wide-angle end according to Numerical Example 2 of the present invention.

FIG. 6 is a lens cross-sectional view at a wide-angle end according to Numerical Example 3 of the present invention.

FIG. 7 is a lens cross-sectional view at a wide-angle end according to Numerical Example 4 of the present invention.

FIG. 8 is a lens cross-sectional view at a wide-angle end according to Numerical Example 5 of the present invention.

FIG. 9 is a lens cross-sectional view at a wide-angle end according to Numerical Example 6 of the present invention.

FIG. 10 is a lens cross-sectional view at a wide-angle end according to Numerical Embodiment 7 of the present invention.

FIG. 11 is a lens cross-sectional view at a wide-angle end according to Numerical Example 8 of the present invention.

FIG. 12 is a lens cross-sectional view at a wide-angle end according to Numerical Embodiment 9 of the present invention.

FIG. 13 is a lens cross-sectional view at a wide-angle end according to Numerical Example 10 of the present invention.

FIG. 14 is a lens cross-sectional view at a wide-angle end according to Numerical Example 11 of the present invention.

FIG. 15 is a lens cross-sectional view at a wide-angle end according to Numerical Example 12 of the present invention.

FIG. 16 is an aberration diagram at the wide-angle end according to Numerical Example 1 of the present invention.

FIG. 17 is an intermediate aberration diagram of Numerical example 1 of the present invention.

FIG. 18 is an aberration diagram at a telephoto end according to Numerical Example 1 of the present invention.

FIG. 19 is an aberration diagram at a wide-angle end according to Numerical Example 2 of the present invention.

FIG. 20 is an intermediate aberration diagram of Numerical example 2 of the present invention.

FIG. 21 is an aberration diagram at a telephoto end according to Numerical Example 2 of the present invention.

FIG. 22 is an aberration diagram at a wide-angle end according to Numerical Example 3 of the present invention.

FIG. 23 is an intermediate aberration diagram of Numerical Example 3 of the present invention.

FIG. 24 is an aberration diagram at a telephoto end according to Numerical Example 3 of the present invention.

FIG. 25 is an aberration diagram at a wide-angle end according to Numerical Example 4 of the present invention.

FIG. 26 is an intermediate aberration diagram of Numerical Example 4 of the present invention.

FIG. 27 is an aberration diagram at a telephoto end according to Numerical Example 4 of the present invention.

FIG. 28 is an aberration diagram at a wide-angle end according to Numerical Example 5 of the present invention.

FIG. 29 is an intermediate aberration diagram of Numerical example 5 of the present invention.

FIG. 30 is an aberration diagram at a telephoto end according to Numerical Example 5 of the present invention.

FIG. 31 is an aberration diagram at a wide-angle end according to Numerical Example 6 of the present invention.

FIG. 32 is an intermediate aberration diagram of Numerical Example 6 of the present invention.

FIG. 33 is an aberration diagram at a telephoto end according to Numerical Example 6 of the present invention.

FIG. 34 is an aberration diagram at the wide-angle end according to Numerical Example 7 of the present invention.

FIG. 35 is an intermediate aberration diagram of Numerical Example 7 of the present invention.

FIG. 36 is an aberration diagram at a telephoto end according to Numerical Example 7 of the present invention.

FIG. 37 is an aberration diagram at a wide-angle end according to Numerical Example 8 of the present invention.

38 is an intermediate aberration diagram of Numerical Example 8 of the present invention. FIG.

FIG. 39 is an aberration diagram at a telephoto end according to Numerical Example 8 of the present invention.

FIG. 40 is an aberration diagram at a wide-angle end according to Numerical Example 9 of the present invention.

FIG. 41 is an intermediate aberration diagram of Numerical Example 9 of the present invention.

FIG. 42 is an aberration diagram at a telephoto end according to Numerical Example 9 of the present invention.

FIG. 43 is an aberration diagram at the wide-angle end according to Numerical Example 10 of the present invention.

FIG. 44 is an intermediate aberration diagram of Numerical Example 10 of the present invention.

FIG. 45 is an aberration diagram at a telephoto end according to Numerical Example 10 of the present invention.

FIG. 46 is an aberration diagram at the wide-angle end according to Numerical Example 11 of the present invention.

FIG. 47 is an intermediate aberration diagram of Numerical Example 11 of the present invention.

FIG. 48 is an aberration diagram at a telephoto end according to Numerical Example 11 of the present invention.

FIG. 49 is an aberration diagram at a wide-angle end according to Numerical Example 12 of the present invention.

FIG. 50 is an intermediate aberration diagram of Numerical Example 12 of the present invention.

FIG. 51 is an aberration diagram at a telephoto end according to Numerical Example 12 of the present invention.

[Explanation of symbols]

 L1 1st group L2 2nd group L3 3rd group L4 4th group L5 5th group SP diaphragm IP image surface d d line g g line S. C Sine condition ΔS Sagittal image plane ΔM Meridional image plane

Claims (7)

[Claims] 1. The first, second and third groups of 3 in order from the object side.
The first lens group is composed of two lens groups, and the composite power at the wide-angle end is a front lens group having a positive power, and the fourth lens group having a positive power and a rear lens group having a second lens group having a negative power. Upon zooming from the wide-angle end to the telephoto end, the first, second, and third groups move so that the combined refractive power of the front group weakens at the telephoto end as compared with the wide-angle end, The fifth group is moved so that the interval between them becomes narrow, the focal length of the i-th group is fi, the focal length of the entire system at the wide-angle end is fW, and the lateral magnification of the i-th group at the wide-angle end is βiW. A zoom lens characterized by satisfying the following conditions: 0.5 <| f5 / fW | <1.5 1.1 <β5W <1.7. 2. The zoom lens according to claim 1, wherein at the wide-angle end, the combined refractive power of the first group and the second group is negative, and the third group has a positive refractive power. 3. When the combined refractive power of the front group at the wide-angle end is φ _123W , the condition of 0.2 <fW · φ _123W <1.0 0.6 <f3 / fW <2.2 must be satisfied. The zoom lens according to claim 2, wherein 4. The front group is composed of a first group having a negative refractive power, a second group having a positive refractive power, and a third group having a positive refractive power, and in zooming from the wide-angle end to the telephoto end, 4. The zoom lens according to claim 3, wherein each lens group is moved so that a distance between the first group and the second group decreases and a distance between the second group and the third group increases. 5. The front group is composed of a first group having a negative refractive power, a second group having a negative refractive power, and a third group having a positive refractive power. 4. The zoom lens according to claim 3, wherein each lens group is moved so that a distance between the first group and the second group increases and a distance between the second group and the third group decreases. 6. The front group is composed of a first group having a positive refractive power, a second group having a negative refractive power, and a third group having a positive refractive power, and in zooming from the wide-angle end to the telephoto end, 4. The zoom lens according to claim 3, wherein each lens group is moved so that the distance between the first group and the second group increases and the distance between the second group and the third group decreases. 7. The zoom lens according to claim 2, wherein the first lens unit and the third lens unit move integrally during zooming.