WO2013183787A1

WO2013183787A1 - Zoom lens

Info

Publication number: WO2013183787A1
Application number: PCT/JP2013/066000
Authority: WO
Inventors: 安達　宣幸
Original assignee: 株式会社タムロン
Priority date: 2012-06-08
Filing date: 2013-06-10
Publication date: 2013-12-12
Also published as: JP5885166B2; JP2013254160A

Abstract

The purpose of the present invention is to provide a compact zoom lens capable of acquiring high imaging performance even with high magnification. The zoom lens comprises, sequentially from an object, a first lens group with positive power, a second lens group with negative power and a third lens group with positive power. When zooming from a wide angle end to a telescopic end, the distance between the first lens group and the second lens group increases and the distance between the second lens group and the third lens group decreases so that all the lens groups constituting the zoom lens move. The first lens group comprises, sequentially from the object, a single negative lens and three positive lenses. The zoom lens satisfies the following expressions: (1) Nd1 > 1.84 vd1 < 35. (2) Nd2 < 1.60 vd2 > 60, (3) Nd3 < 1.65 vd3 > 60 and (4) Nd4 - Nd3 >0.02 Nd4 > Nd3 >Nd2. Where, Ndi is the refractive index of an i-th glass material from the object and Vdi is Abbe's number of an i-th glass material from the object.

Description

Zoom lens

The present invention relates to a zoom lens, more specifically, a compact, at least three-group configuration, including a positive first lens group, a negative second lens group, and a positive third lens group in order from the object side, and a zoom ratio. The present invention relates to a zoom lens having a high magnification of about 10 times.

As the conventional high-power zoom lens described above, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a third lens having a positive refractive power. It has at least a fourth lens group G4 having a negative refractive power and a fifth lens group G5 having a positive refractive power at the telephoto end, and the first lens group G1 and the second lens group G3. The air gap between the lens group G2 increases, the air gap between the second lens group G2 and the third lens group G3 decreases, and the third lens group G3 and the fourth lens group G4 The distance between the first lens group G1 and the second lens group G1 at the telephoto end is changed by expanding the air distance between the fourth lens group G4 and the fifth lens group G5. The distance between the lens groups G2 is D1T, and the first lens group G1 at the wide-angle end is The interval between the second lens group G2 and D1W, the focal length of the entire system at the wide angle end fw, the focal length of the first lens group G1 f1, the focal length of the second lens group G2 and the f2,
(1) 2.3 <(D1T−D1W) / fw <10
(2) 6.6 <f1 / | f2 | <15
A zoom lens satisfying the above has been proposed (see, for example, Patent Document 1).

As another conventional high-power zoom lens, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, and a negative refraction. A fourth lens group having a positive refractive power and a fifth lens group having a positive refractive power, and the distance between the first lens group and the second lens group increases upon zooming from the wide-angle end to the telephoto end. At least the first lens group, so that the distance between the third lens group and the third lens group decreases, the distance between the third lens group and the fourth lens group increases, and the distance between the fourth lens group and the fifth lens group decreases. A zoom lens for moving the third lens group and the fifth lens group to the object side, wherein the focal lengths of the first lens group and the third lens group are f1, f3, and the focal points of the entire system at the wide-angle end and the telephoto end, respectively. The distances are fW and fT, respectively (paraxial lateral magnification at the telephoto end) / (paraxial lateral magnification at the wide-angle end). When the variable magnification sharing values of the second lens group and the third lens group defined are Z2 and Z3, respectively, 0.3 <f1 / fT <0.8, 1.2 <Z2 / Z3 <3.0 , 0.5 <f3 / fW <0.8 has been proposed (for example, see Patent Document 2).

As a conventional higher magnification zoom lens, in order from the object side, a first lens unit having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, and a fourth lens having a negative refractive power. And a fifth lens group having positive refractive power, and at the time of zooming from the wide angle end to the telephoto end, the distance between the first lens group and the second lens group, and the third lens group and the fourth lens group. The zoom lens is characterized in that the distance between the second lens group and the third lens group and the distance between the fourth lens group and the fifth lens group are reduced, and the following conditional expression is satisfied.
2.0 <f1 / fW ≦ 4.8424 (1)
0.4 <| f2 / fW | <1.0 (2)
0.3 <f3 / fT345 ≦ 0.8217 (3)
0.6 <| f4 | / fT345 <5.0 (4)
0.9154 ≦ f5 / fT345 <4.0 (5)
However,
fW is the focal length f1 of the entire system at the wide angle end, the focal length f2 of the first lens group, the focal length f3 of the second lens group, and the focal length f4 of the third lens group is the focal point of the fourth lens group. A zoom lens has been proposed in which the distance f5 is the focal length fT345 of the fifth lens group, and the focal length is from the third lens group to the fifth lens group at the telephoto end (see Patent Document 3, for example).

Japanese Patent No. 4051731 Japanese Patent No. 3236037 Japanese Patent No. 3807712

In the zoom lens disclosed in Patent Document 1 or the like, with the same lens group configuration as that of the present invention, the air distance between the first lens group and the second lens group is narrowed, and the focal length between the first lens group and the second lens group is further reduced. We have proposed an optical system that is made compact by shortening it. However, the zoom lens of Patent Document 1 does not reach the target size of the present invention, and is not compact enough. Furthermore, the lens type disclosed in Patent Document 1 has a limit in improving the deterioration of the spherical aberration and the longitudinal chromatic aberration at the telephoto end due to compactification.

In the zoom lens disclosed in Patent Document 2 and the like, an optical system having the same power distribution as those in Embodiments 4 to 12 of the five lens group of the present invention is proposed. It is not. In particular, correction of spherical aberration and axial chromatic aberration at the telephoto end is insufficient. Compactness is also insufficient.

In the zoom lens disclosed in Patent Document 3 and the like, an optical system having the same power distribution as in Embodiments 4 to 12 of the five lens group of the present invention is proposed. However, since the number of constituent lenses is small, it is difficult to satisfy the imaging performance. In particular, the correction of chromatic aberration at the telephoto end is insufficient, and the compactness is also insufficient.

(Object of invention)
The present invention has been made in view of the above-described problems of conventional zoom lenses, and an object of the present invention is to provide a compact zoom lens that can obtain high imaging performance while having a high magnification.

In general, the high-power zoom lens is made compact to make it difficult to ensure the imaging performance at the telephoto end. This is because the axial chromatic aberration and the lateral chromatic aberration at the telephoto end are significantly deteriorated by shortening the focal length of the first lens group. In order to solve this problem, conventionally, each lens group has an appropriate focal length, a material with high anomalous dispersion is incorporated, and chromatic aberration is improved to produce a product. However, in order to realize attractive compactness, there is a limit in the configuration of the first lens group having three lenses which is a conventional lens type.

It is well known that the first lens group has a four-lens configuration and is suitable for chromatic aberration correction. However, a zoom lens suitable for downsizing, which is a lens type in which a plurality of lens groups move, has a four-lens first lens group as in the present invention, has a short overall length, and a small outer diameter of the first lens group, has been proposed. Not. SUMMARY OF THE INVENTION An object of the present invention is to provide a zoom lens in which the first lens group is composed of four lenses to correct chromatic aberration and realize a compact size.

(First invention)
In order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens group having a positive refractive power,
At the time of zooming from the wide-angle end to the telephoto end, the distance between the first lens group and the second lens group increases, the distance between the second lens group and the third lens group decreases, and all the lens groups constituting the lens group A moving zoom lens,
The first lens group includes one negative lens and three positive lenses in order from the object side, and satisfies the following conditional expression.
(1) Nd1> 1.84 vd1 <35
(2) Nd2 <1.60 vd2> 60
(3) Nd3 <1.65 vd3> 60
(4) Nd4-Nd3> 0.02 Nd4>Nd3> Nd2
Ndi: Refractive index of the i-th glass material from the object side
Vdi: Abbe number of the i-th glass material from the object side

(Embodiment of the first invention)
In the first invention, the following conditional expression is satisfied.
(5) 0.24 <f1 / ft <0.42
(6) 0.03 <| f2 / ft | <0.06
(7) 0.05 <f3 / ft <0.23
(8) 3.1 <Z2 <5.8
f1: focal length of the first lens group f2: focal length of the second lens group f3: focal length of the third lens group ft: focal length at the telephoto end Z2: paraxial imaging magnification at the telephoto end of the second lens group To the paraxial magnification at the wide-angle end

(Second invention)
In order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, a fourth lens group having a negative refractive power, and a positive refractive power Of the fifth lens group,
At the time of zooming from the wide-angle end to the telephoto end, the distance between the first lens group and the second lens group is increased, the distance between the second lens group and the third lens group is decreased, and the third lens group and the second lens group are The first lens group, the third lens group, the fourth lens group, and the fifth lens group are placed on the object side so that the distance between the four lens groups changes and the distance between the fourth lens group and the fifth lens group decreases. A zoom lens to be moved to
The first lens group includes one negative lens and three positive lenses in order from the object side, and satisfies the following conditional expression.
(1) Nd1> 1.84 vd1 <35
(2) Nd2 <1.60 vd2> 60
(3) Nd3 <1.65 vd3> 60
(4) Nd4-Nd3> 0.02 Nd4>Nd3> Nd2
Ndi: Refractive index of the i-th glass material from the object side
Vdi: Abbe number of the i-th glass material from the object side

(Embodiment of the second invention)
In the second invention, the following conditional expression is satisfied.
(5) 0.24 <f1 / ft <0.42
(6) 0.03 <| f2 / ft | <0.06
(9) 0.39 <f345t / f3 <1.39
f1: Focal length of the first lens group f2: Focal length of the second lens group f3: Focal length of the third lens group ft: Focal length at the telephoto end f345t: From the third lens group to the fifth lens group at the telephoto end Composite focal length

(Third invention)
In order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, a fourth lens group having a negative refractive power, and a positive refractive power Of the fifth lens group,
At the time of zooming from the wide-angle end to the telephoto end, the distance between the first lens group and the second lens group is increased, the distance between the second lens group and the third lens group is decreased, and the third lens group and the second lens group are The first lens group, the third lens group, the fourth lens group, and the fifth lens group are placed on the object side so that the distance between the four lens groups changes and the distance between the fourth lens group and the fifth lens group decreases. A zoom lens to be moved to
The first lens group is composed of one negative lens and three positive lenses in order from the object side, and a part or the whole of the fourth lens group moves during camera shake correction, and satisfies the following conditional expression: Zoom lens characterized by.
(1) Nd1> 1.84 vd1 <35
(2) Nd2 <1.60 vd2> 60
(3) Nd3 <1.65 vd3> 60
(4) Nd4-Nd3> 0.02 Nd4>Nd3> Nd2
Ndi: Refractive index of the i-th glass material from the object side
Vdi: Abbe number of the i-th glass material from the object side

(Embodiment of the third invention)
In the third invention, the following conditional expression is satisfied.
(5) 0.24 <f1 / ft <0.42
(6) 0.03 <| f2 / ft | <0.06
(10) -2.0 <f4 / f345t <2.3
f1: Focal length of the first lens group f2: Focal length of the second lens group f4: Focal length of the fourth lens group ft: Focal length at the telephoto end f345t: From the third lens group to the fifth lens group at the telephoto end Composite focal length

(Embodiments of the second and third inventions)
In the second and third inventions, the following conditional expressions are satisfied.
(11) -17.8 <Z5 <9.5
Z5: (Magnification of the fifth lens unit at the telephoto end) / (Magnification of the fifth lens unit at the wide-angle end)

(Embodiment 1 of the first to third inventions)
In the first to third inventions, the third lens group is composed of three convex lenses and one concave lens in order from the object side.

(Embodiment 2 of the first to third inventions)
In the first to third inventions, all the lens groups except the first lens group have an aspherical surface.

(Embodiment 3 of the first to third inventions)
In the first to third inventions, the aperture stop is disposed between the second lens group and the third lens group, and moves integrally with the third lens group.

According to the zoom lens of the present invention, it is possible to construct a compact zoom lens that can obtain a high imaging performance while having a high magnification with the first lens group having four lenses.

(Explanation of conditional expressions)
In general, a lens system having four first lens groups is not preferable because the first lens group becomes large. Further, the addition of one lens to the first lens group in the three-lens configuration increases the overall length of the zoom lens. In addition, the first lens diameter increases as the entrance pupil position becomes deeper. The present invention reasonably solves the above-described problems with the following conditional expressions.

It is desirable to reduce the refractive index of the convex lens of the first lens group from the fourth side to the second lens in order from the object side in order to make the front lens diameter compact while improving the imaging performance. .

In the present invention, the refractive index of the glass material of the lens closest to the object side in the first lens group is set in the range of the conditional expression (1), and the refractive index of the glass material of the second lens is set in the range of the conditional expression (2). Then, the refractive index of the glass material of the third lens is set in the range of the conditional expression (3), the refractive index of the fourth lens and the third lens is set in the range of the condition (4), and the first lens group We are trying to make it more compact.

That is,
(1) Nd1> 1.84 vd1 <36
However,
Ndi: Refractive index of the i-th glass material from the object side
Vdi: Abbe number of the i-th glass material counted from the object side If a glass material having a small refractive index exceeding the range of conditional expression (1) is selected, the first lens unit cannot be made compact.

The glass material of the second convex lens counted from the object side must satisfy the following conditions.
(2) Nd2 <1.60 vd2> 60
Selecting a glass material having a large refractive index that exceeds the range of conditional expression (2) is not desirable because it becomes difficult to correct chromatic aberration.

Further, the glass material of the third convex lens counted from the object side needs to satisfy the following conditions.
(3) Nd3 <1.65 vd3> 60
Selecting a glass material having a large refractive index that exceeds conditional expression (3) is not desirable because it becomes difficult to optimize spherical aberration and chromatic aberration at the telephoto end.

Further, the glass materials of the third and fourth convex lenses counted from the object side need to satisfy the following conditions.
(4) Nd4-Nd3> 0.02 Nd4>Nd3> Nd2
Increasing the refractive index of the glass material of the fourth convex lens relative to the third convex lens is preferable in order to optimize the spherical aberration chromatic aberration at the telephoto end while reducing the size of the first lens group. In order to efficiently reduce the effective diameter of the first lens group, it is preferable to sequentially reduce the refractive index from the image side to the object side in the three convex lenses constituting the first lens group.

Conditional expression (5) shortens the total lens length, particularly the total length at the telephoto end, while shortening the focal length of the first lens group. Further, it is also a condition that the diameter of the lens barrel is reduced by reducing the diameter of the light beam incident on the image side from the second lens group and reducing the diameter of the aperture, thereby avoiding the enlargement of the aperture unit.
If the focal length of the first lens group is shortened beyond the lower limit value, the spherical aberration on the telephoto side that occurs in this group becomes remarkably large, and it is difficult to correct this mutually in the lens groups after the second lens group. It becomes.
If the upper limit is exceeded, in addition to the purpose of downsizing, the lens movement amount for obtaining the desired zoom ratio must be given, and when the lens barrel is composed of a cam barrel or the like, The holding structure of the connecting portion becomes complicated and its design becomes difficult.
Conditional expression (5) preferably satisfies 0.26 <f1 / ft <0.38. With this condition, the imaging performance in the telephoto state can be further enhanced.

Conditional expression (6) is a condition for setting an appropriate power arrangement range of the second lens group. For example, when trying to achieve a zoom lens having an angle of view of 70 ° or more and a zoom ratio of 10 times or more by downsizing and reducing the diameter, the power balance between the first lens group and the second lens group becomes important. In particular, in the present invention, since a strong retrofocus power arrangement is used at the wide-angle end, in order to achieve good aberration correction, the power balance of the second lens group is appropriately set in combination with the conditional expression (1). Conditional expression (6) is necessary.
If the upper limit of conditional expression (6) is exceeded, the focal length of the second lens group has a relatively large absolute value, that is, the power of the second lens group is set to a relatively loose value. In this case, the amount of movement at the time of zooming increases, leading to an increase in the size of the entire system and an increase in the total length. Further, since the power of the first lens group becomes relatively strong, the incident height of the chief ray at the wide-angle end increases, resulting in an increase in filter size, which is not preferable.
When falling below the lower limit of conditional expression (6), the focal length of the second lens group has a relatively small absolute value, that is, the power of the second lens group is set to a relatively strong value. In this case, the distortion on the wide-angle side increases, the astigmatism increases due to the deterioration of the Petzval sum, the fluctuation due to the zooming of the lower coma aberration, the increase of the spherical aberration on the telephoto side, etc., which is not preferable.
By setting the lower limit of conditional expression (6) to a value larger than 0.04, it is possible to make the filter size smaller. Furthermore, the effect of the present invention can be maximized by setting the upper limit of conditional expression (6) to a value smaller than 0.05.

Conditional expression (7) defines the focal length of the third lens group. Although it is inevitable that the focal length of the third lens group is shortened in order to reduce the overall length, if an optical system having a compact and high imaging performance is to be obtained, the residual aberration generated in the third lens group is appropriately suppressed. I have to. Conditional expression (7) is a condition that gives a good balance between the amount of aberration and the total length by appropriately giving the focal length.
If the focal length is shortened beyond the lower limit of the conditional expression (7), it is difficult to correct the aberration generation by the third lens group, which is not preferable.
Exceeding the upper limit of conditional expression (7) is not preferable because the back focus becomes long and it becomes difficult to make the entire length compact.
Regarding conditional expression (7), it is preferable that 0.06 <f3 / ft <0.21. The imaging performance from wide to tele, especially the difference in spherical aberration can be reduced.

Conditional expression (8) is a conditional expression that defines the ratio of paraxial imaging magnification between the telephoto end and the wide-angle end of the second lens group. In order to make the optical system compact, it is necessary to devise a method for reducing the diameter of the first lens group. In order to reduce the outer diameter of the first lens group in the zoom lens of the present invention, it is essential to appropriately set the zoom ratio of the front and rear lens groups that greatly contribute to zooming. If the zoom ratio of the lens unit on the object side is smaller than that of the stop and the zoom ratio of the lens group on the image side is increased, the stop position can be arranged on the object side, so the entrance pupil position is shallow. Thus, the outer diameter of the first lens group can be reduced.
If the zoom ratio is reduced beyond the lower limit of conditional expression (8), the outer diameter of the object-side lens of the first lens group can be reduced, but the focal length of the second lens group is reduced and the image plane at the wide-angle end is reduced. Overcurvation is caused and desired imaging performance cannot be obtained. Further, the subsequent lens group is enlarged, which is not preferable.
If the zoom ratio of the second group increases beyond the lower limit of conditional expression (8), the outer diameter of the object side lens of the first lens group increases, which is not preferable.
Regarding conditional expression (8), it is preferable that 3.4 <Z2 <5.2. The imaging performance from wide to tele, especially the difference in field curvature can be reduced.

Conditional expression (9) defines the combined focal length of the third lens group to the fifth lens group. In order to reduce the overall length, it is inevitable to shorten the combined focal length of the third lens unit to the fifth lens unit. However, if an optical system having a compact and high imaging performance is to be obtained, the third lens unit is changed from the third lens unit to the fifth lens unit. Residual aberrations generated in the five lens groups must be appropriately suppressed. Conditional expression (9) is a condition for giving a good balance between the amount of aberration and the total length by appropriately giving the focal length.
If the focal length is shortened beyond the lower limit of the conditional expression (9), it is difficult to correct the aberrations caused by the third lens group to the fifth lens group, which is not preferable.
Exceeding the upper limit of conditional expression (9) is not preferable because the back focus becomes long and it becomes difficult to make the entire length compact.
In the present invention, the third lens group includes three convex lenses and a concave lens in order from the object side. This arrangement is particularly preferable for correcting coma on the lower ray side of off-axis rays at the wide-angle end.
Furthermore, the spherical aberration correction on the tele side can be corrected simultaneously.
Regarding conditional expression (9), 0.43 <f345t / f3 <1.25 is preferable. The imaging performance from wide to tele, especially the difference in spherical aberration can be reduced.

Conditional expression (10) defines the focal length of the fourth lens group. The fourth lens group is a group that contributes to the correction of the spherical aberration at the intermediate focal length, and is an important lens group for improving the imaging performance in the entire zoom range from the wide-angle end to the telephoto end. In addition, when the fourth lens group is set as a camera shake correction group, it is necessary to set an appropriate focal length in order to prevent deterioration in image forming performance during camera shake correction.
If the lower limit of conditional expression (10) is exceeded and the focal length of the fourth lens group becomes shorter, the spherical aberration at the intermediate focal length becomes under and it becomes impossible to ensure a flat image surface property. Furthermore, the off-axis light beam passing through the fifth lens group becomes high, and the peripheral light amount decreases. It is not preferable.
If the focal length of the fourth lens unit is increased beyond the upper limit of the conditional expression (10), the spherical aberration at the intermediate focal length is over, and it becomes impossible to ensure flat image surface property. The total length of is increased, which is not preferable.
Regarding conditional expression (10), it is preferable that −2.0 <f4 / f345t <2.3. The imaging performance from wide to tele, especially the difference in spherical aberration can be reduced.

It is preferable that the aspherical surface in the second lens group be arranged closest to the object side. This is for maintaining good distortion. An aspherical surface can be disposed closest to the image side in the second lens group, and the curvature of field at the intermediate focal length from the wide angle end can be maintained well.

The aspherical surface that can be placed in the third lens group is preferably arranged on the surface closer to the image side. Since the third lens group is a lens group through which Fno rays pass thickly, there is a great influence on the imaging performance due to local deformation and surface waviness on all lens surfaces. Among them, the present invention obtains high imaging performance while maintaining high magnification by lowering the Fno ray toward the image side to make the light beam narrower and selecting an aspherical surface in the image side direction. The problem can be realized. More preferably, the second to fourth lenses from the object side are provided with aspheric surfaces.
The aspherical surface in the fourth lens group is effective in enhancing the imaging performance by the camera shake correction when the fourth lens group is a camera shake correction lens group.

It is an optical sectional view at the wide-angle end of the lens configuration according to the first embodiment of the zoom lens of the present invention. FIG. 6 is a spherical aberration diagram, an astigmatism diagram, and a distortion diagram when the zoom lens according to the first embodiment of the present invention is in focus at infinity in the wide-angle end state. FIG. 6 is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram at the time of focusing on infinity in the intermediate focal length state of the lens according to the first embodiment of the zoom lens of the present invention. FIG. 3 is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram at the time of focusing on infinity in the telephoto end state of the zoom lens according to the first embodiment of the present invention. It is an optical sectional view at the wide angle end of a lens configuration concerning a 2nd embodiment of a zoom lens of the present invention. FIG. 6 is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram at the time of focusing on infinity in the wide-angle end state of the lens according to the second embodiment of the zoom lens of the present invention. FIG. 7 is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram at the time of focusing on infinity in the intermediate focal length state of the lens according to the second embodiment of the zoom lens of the present invention. FIG. 6 is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram at the time of focusing on infinity in the telephoto end state of the lens according to the second embodiment of the zoom lens of the present invention. It is an optical sectional view in the wide angle end of a lens composition concerning a 3rd embodiment of a zoom lens of the present invention. It is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram at the time of focusing on infinity in the wide-angle end state of the zoom lens according to the third embodiment of the present invention. It is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram at the time of focusing on infinity in the intermediate focal length state of the lens according to the third embodiment of the zoom lens of the present invention. FIG. 10 is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram at the time of focusing on infinity in the telephoto end state of the zoom lens according to the third embodiment of the present invention. It is an optical sectional view in the wide angle end of a lens composition concerning a 4th embodiment of a zoom lens of the present invention. FIG. 10 is a spherical aberration diagram, an astigmatism diagram, and a distortion diagram when the zoom lens according to the fourth embodiment of the present invention is focused on infinity in the wide-angle end state. FIG. 10 is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram at the time of focusing on infinity in the intermediate focal length state of the lens according to the fourth embodiment of the zoom lens of the present invention. It is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram at the time of focusing on infinity in the telephoto end state of the lens according to Embodiment 4 of the zoom lens of the present invention. It is an optical sectional view in the wide angle end of a lens composition concerning a 5th embodiment of a zoom lens of the present invention. It is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram at the time of focusing on infinity in the wide-angle end state of the zoom lens according to the fifth embodiment of the present invention. It is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram at the time of focusing on infinity in the intermediate focal length state of the lens according to the fifth embodiment of the zoom lens of the present invention. It is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram at the time of focusing on infinity in the telephoto end state of the zoom lens according to the fifth embodiment of the present invention. It is an optical sectional view at the wide-angle end of a lens configuration concerning a 6th embodiment of a zoom lens according to the present invention. It is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram at the time of focusing on infinity in the wide-angle end state of the zoom lens according to the sixth embodiment of the present invention. It is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram at the time of focusing on infinity in the intermediate focal length state of the lens according to Sixth Embodiment of the zoom lens of the present invention. It is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram at the time of focusing on infinity in the telephoto end state of the zoom lens according to the sixth embodiment of the present invention. It is an optical sectional view in the wide-angle end of a lens composition concerning a 7th embodiment of a zoom lens of the present invention. It is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram at the time of focusing on infinity in the wide angle end state of the zoom lens according to the seventh embodiment of the present invention. It is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram at the time of focusing on infinity in the intermediate focal length state of the lens according to the seventh embodiment of the zoom lens of the present invention. It is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram at the time of focusing on infinity in the telephoto end state of the zoom lens according to the seventh embodiment of the present invention. It is an optical sectional view at the wide-angle end of a lens configuration concerning an eighth embodiment of a zoom lens according to the present invention. It is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram at the time of focusing on infinity in the wide-angle end state of the zoom lens according to the eighth embodiment of the present invention. It is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram at the time of focusing on infinity in the intermediate focal length state of the lens according to the eighth embodiment of the zoom lens of the present invention. It is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram at the time of focusing on infinity in the telephoto end state of the lens according to Embodiment 8 of the zoom lens of the present invention. It is an optical sectional view at the wide-angle end of a lens configuration concerning a 9th embodiment of a zoom lens according to the present invention. It is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram at the time of focusing on infinity in the wide angle end state of the zoom lens according to the ninth embodiment of the present invention. It is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram at the time of focusing on infinity in the intermediate focal length state of the lens according to the ninth embodiment of the zoom lens of the present invention. It is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram at the time of focusing on infinity in the telephoto end state of the zoom lens according to the ninth embodiment of the present invention. It is an optical sectional view in the wide angle end of a lens composition concerning a 10th embodiment of a zoom lens of the present invention. It is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram at the time of focusing on infinity in the wide-angle end state of the zoom lens according to the tenth embodiment of the present invention. It is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram at the time of focusing on infinity in the intermediate focal length state of the lens according to the tenth embodiment of the zoom lens of the present invention. It is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram at the time of focusing on infinity in the telephoto end state of the zoom lens according to the tenth embodiment of the present invention. It is an optical sectional view at the wide-angle end of a lens configuration concerning an eleventh embodiment of the zoom lens according to the present invention. It is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram at the time of focusing on infinity in the wide-angle end state of the zoom lens according to the eleventh embodiment of the present invention. It is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram at the time of focusing on infinity in the intermediate focal length state of the lens according to Embodiment 11 of the zoom lens of the present invention. It is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram at the time of focusing on infinity in the telephoto end state of the zoom lens according to the eleventh embodiment of the present invention. It is an optical sectional view in the wide-angle end of a lens configuration concerning a 12th embodiment of a zoom lens according to the present invention. It is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram at the time of focusing on infinity in the wide-angle end state of the zoom lens according to the twelfth embodiment of the present invention. It is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram at the time of focusing on infinity in the intermediate focal length state of the lens according to the twelfth embodiment of the zoom lens of the present invention. It is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram at the time of focusing on infinity in the telephoto end state of the zoom lens according to the twelfth embodiment of the present invention.

In the embodiment shown below, the surface number NS in the specification optical data is the order of the lens surface counted from the object side, R is the radius of curvature of the lens surface (mm), and D is the distance on the optical axis of the lens surface (mm). , Nd represents the refractive index for the d-line (wavelength λ = 587.6 nm), and νd represents the Abbe number for the d-line (wavelength λ = 587.6 nm). Also, the surface number with STOP attached to the rear side indicates a stop. The surface number with ASPH on the back side indicates an aspheric surface, and the column of the radius of curvature R indicates the paraxial radius of curvature (mm) of the aspheric surface.

In the above table, an aspherical surface with ASPH on the back side of the surface number is represented by the following equation.
X (y) = (y ² / R) / [1+ (1−ε · y ² / R ² ) ^1/2 ] + A 4 · y ⁴ + A 6 · y ⁶ + A 8 · y ⁸ + A 10 · y ¹⁰
Here, X (y) is the distance (sag amount) along the optical axis direction from the apex of each aspheric surface at the height y in the vertical direction from the optical axis, R is the curvature radius (paraxial curvature radius) of the reference spherical surface, ε is a conical coefficient, and A4, A6, A8, and A10 are aspherical coefficients.

In the following, changes in the surface interval in zoom operation, that is, the surface interval in the wide-angle end state (f = 28.5457 mm), the intermediate focal length state (f = 91.5008 mm), and the telephoto end state (f = 291.2659 mm) are shown.
f 28.5457 91.5008 291.2659
D (7) 1.8099 30.7948 53.6750
D (15) 20.3407 10.3361 0.9800
D (23) 7.4741 3.1732 0.6809
D (34) 42.6549 76.0270 96.6281

In the following, changes in the surface interval during zoom operation, that is, the surface intervals in the wide-angle end state (f = 28.8400 mm), the intermediate focal length state (f = 91.5017 mm), and the telephoto end state (f = 291.2648 mm) are shown.
f 28.8400 91.5017 291.2648
D (7) 1.4914 29.9944 53.3812
D (15) 17.3679 9.1947 1.3409
D (27) 9.5335 3.0114 0.6797
D (37) 39.9998 75.8619 89.9911

In the following, changes in the surface interval during zoom operation, that is, the surface interval in the wide-angle end state (f = 28.8400 mm), the intermediate focal length state (f = 91.4998 mm), and the telephoto end state (f = 291.2621 mm) are shown.
f 28.8400 91.4998 291.2621
D (7) 1.0567 30.9510 53.0979
D (15) 16.8921 8.8481 0.8134
D (35) 40.0000 73.7383 94.0183

In the following, changes in the surface interval during zoom operation, that is, the surface intervals in the wide-angle end state (f = 28.8400 mm), the intermediate focal length state (f = 91.4978 mm), and the telephoto end state (f = 291.9106 mm) are shown.
f 28.8400 91.4978 291.9106
D (7) 1.5848 29.3804 53.3355
D (15) 17.4488 8.8591 1.3179
D (23) 2.1872 3.9166 3.6301
D (27) 9.5117 3.2729 0.6567
D (37) 41.2269 74.4210 89.8828

In the following, changes in the surface interval in zoom operation, that is, the surface interval in the wide-angle end state (f = 28.7690 mm), the intermediate focal length state (f = 91.4978 mm), and the telephoto end state (f = 291.9106 mm) are shown.
f 28.7960 91.5003 291.2646
D (7) 1.8099 34.1120 54.2662
D (15) 18.7574 10.2822 0.9800
D (23) 11.1754 5.4379 1.0000
D (26) 5.6467 4.7725 1.5783
D (34) 40.3618 66.1272 89.8230

In the following, changes in the surface interval in zoom operation, that is, the surface interval in the wide-angle end state (f = 28.8400 mm), the intermediate focal length state (f = 91.4986 mm), and the telephoto end state (f = 291.2633 mm) are shown.
f 28.8400 91.4986 291.2633
D (7) 1.7000 38.0000 62.6908
D (15) 17.6703 9.4203 0.9800
D (23) 9.5131 3.3814 1.0000
D (26) 3.9394 3.1524 0.5000
D (34) 40.8665 69.0556 93.9552

In the following, changes in the surface interval during zoom operation, that is, the surface intervals in the wide-angle end state (f = 28.7760 mm), the intermediate focal length state (f = 91.5000 mm), and the telephoto end state (f = 291.2621 mm) are shown.
f 28.7760 91.5000 291.2621
D (7) 1.7749 29.8104 55.2778
D (15) 18.7563 9.2121 1.3652
D (23) 1.9370 3.9682 3.7576
D (27) 9.9943 3.2110 0.4000
D (37) 40.1487 73.8282 89.5105

In the following, changes in the surface interval in zoom operation, that is, the surface interval in the wide-angle end state (f = 28.8400 mm), the intermediate focal length state (f = 91.5019 mm), and the telephoto end state (f = 291.2621 mm) are shown.
f 28.8400 91.5019 291.2621
D (7) 1.5646 28.7572 54.8326
D (16) 19.1273 9.4444 1.3000
D (24) 1.8201 3.2665 2.5548
D (28) 9.6480 3.0416 0.4000
D (38) 39.0434 74.3198 88.5154

In the following, changes in the surface interval in zoom operation, that is, the surface interval in the wide-angle end state (f = 28.7442 mm), the intermediate focal length state (f = 91.4991 mm), and the telephoto end state (f = 291.5990 mm) are shown.
F 28.7442 91.4991 291.5990
D (7) 5.4575 29.6109 54.8055
D (16) 18.0576 8.8108 1.3295
D (24) 0.1636 1.9296 5.0546
D (28) 9.5223 2.8824 0.1500
D (37) 40.0643 76.7149 88.7267

In the following, the change in the surface interval in zoom operation, that is, the surface interval in the wide-angle end state (f = 28.7959 mm), the intermediate focal length state (f = 91.5116 mm), and the telephoto end state (f = 291.2621 mm) will be shown.
F 28.7959 91.5116 291.2621
D (7) 2.1321 27.3283 55.4292
D (15) 18.9992 9.4912 1.6641
D (23) 1.0524 4.2277 4.0844
D (27) 7.1106 2.0361 0.1500
D (36) 40.0020 75.5249 84.8693

In the following, changes in the surface interval in zoom operation, that is, the surface intervals in the wide-angle end state (f = 28.5215 mm), the intermediate focal length state (f = 91.4992 mm), and the telephoto end state (f = 291.2621 mm) are shown.
f 28.5215 91.4992 291.2621
D (7) 0.5999 34.2348 56.7829
D (16) 19.2430 9.4166 1.1174
D (24) 1.0976 4.4620 2.3121
D (28) 9.9078 3.6736 0.1500
D (37) 40.2236 64.2124 91.7096

In the following, changes in the surface interval during zoom operation, that is, the surface intervals in the wide-angle end state (f = 28.8400 mm), the intermediate focal length state (f = 91.5003 mm), and the telephoto end state (f = 291.2621 mm) are shown.
f 28.8400 91.5003 291.2621
D (7) 0.5119 34.3502 58.9247
D (16) 19.9354 9.7842 1.1474
D (24) 1.0011 4.0400 2.6181
D (28) 9.4599 3.2931 0.1500
D (36) 40.0089 65.6117 89.0771

The value of the conditional expression of each embodiment is shown below.

STOP diaphragm G1 first lens group G2 second lens group G3 third lens group G4 fourth lens group G5 fifth lens group

Claims

In order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens group having a positive refractive power,
At the time of zooming from the wide-angle end to the telephoto end, the distance between the first lens group and the second lens group increases, the distance between the second lens group and the third lens group decreases, and all the lens groups constituting the lens group A moving zoom lens,
The first lens group includes one negative lens and three positive lenses in order from the object side, and satisfies the following conditional expression.
(1) Nd1> 1.84 vd1 <35
(2) Nd2 <1.60 vd2> 60
(3) Nd3 <1.65 vd3> 60
(4) Nd4-Nd3> 0.02 Nd4>Nd3> Nd2
Ndi: Refractive index of the i-th glass material from the object side
Vdi: Abbe number of the i-th glass material from the object side
The zoom lens (5) according to claim 1, wherein the following conditional expression is satisfied: 0.24 <f1 / ft <0.42.
(6) 0.03 <| f2 / ft | <0.06
(7) 0.05 <f3 / ft <0.23
(8) 3.1 <Z2 <5.8
f1: focal length of the first lens group f2: focal length of the second lens group f3: focal length of the third lens group ft: focal length at the telephoto end Z2: paraxial imaging magnification at the telephoto end of the second lens group To the paraxial magnification at the wide-angle end
In order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, a fourth lens group having a negative refractive power, and a positive refractive power Of the fifth lens group,
At the time of zooming from the wide-angle end to the telephoto end, the distance between the first lens group and the second lens group is increased, the distance between the second lens group and the third lens group is decreased, and the third lens group and the second lens group are At least the first lens group, the third lens group, the fourth lens group, and the fifth lens group are objects so that the distance between the four lens groups changes and the distance between the fourth lens group and the fifth lens group decreases. A zoom lens that moves to the side,
The first lens group includes one negative lens and three positive lenses in order from the object side, and satisfies the following conditional expression.
(1) Nd1> 1.84 vd1 <35
(2) Nd2 <1.60 vd2> 60
(3) Nd3 <1.65 vd3> 60
(4) Nd4-Nd3> 0.02 Nd4>Nd3> Nd2
Ndi: Refractive index of the i-th glass material from the object side
Vdi: Abbe number of the i-th glass material from the object side
4. The zoom lens according to claim 3, wherein the following conditional expression is satisfied: 0.24 <f1 / ft <0.42.
(6) 0.03 <| f2 / ft | <0.06
(9) 0.39 <f345t / f3 <1.39
f1: Focal length of the first lens group f2: Focal length of the second lens group f3: Focal length of the third lens group ft: Focal length at the telephoto end f345t: From the third lens group to the fifth lens group at the telephoto end Composite focal length
In order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, a fourth lens group having a negative refractive power, and a positive refractive power Of the fifth lens group,
At the time of zooming from the wide-angle end to the telephoto end, the distance between the first lens group and the second lens group is increased, the distance between the second lens group and the third lens group is decreased, and the third lens group and the second lens group are At least the first lens group, the third lens group, the fourth lens group, and the fifth lens group are objects so that the distance between the four lens groups changes and the distance between the fourth lens group and the fifth lens group decreases. A zoom lens that moves to the side,
The first lens group is composed of one negative lens and three positive lenses in order from the object side, and a part or the whole of the fourth lens group moves during camera shake correction, and satisfies the following conditional expression: Zoom lens characterized by.
(1) Nd1> 1.84 vd1 <35
(2) Nd2 <1.60 vd2> 60
(3) Nd3 <1.65 vd3> 60
(4) Nd4-Nd3> 0.02 Nd4>Nd3> Nd2
Ndi: Refractive index of the i-th glass material from the object side
Vdi: Abbe number of the i-th glass material from the object side
The zoom lens according to claim 5, wherein the following conditional expression is satisfied: 0.24 <f1 / ft <0.42
(6) 0.03 <| f2 / ft | <0.06
(10) -2.0 <f4 / f345t <2.3
f1: Focal length of the first lens group f2: Focal length of the second lens group f4: Focal length of the fourth lens group ft: Focal length at the telephoto end f345t: From the third lens group to the fifth lens group at the telephoto end Composite focal length
The zoom lens (11) -17.8 <Z5 <9.5 according to claim 3 or 5, wherein the following conditional expression is satisfied:
Z5: (Magnification of the fifth lens unit at the telephoto end) / (Magnification of the fifth lens unit at the wide-angle end)
The zoom lens according to one of claims 1 to 7, wherein the third lens group includes three convex lenses and a concave lens in order from the object side.
9. The zoom lens according to claim 1, wherein all lens groups except the first lens group have aspheric surfaces.
10. The zoom lens according to claim 1, wherein an aperture stop is disposed between the second lens group and the third lens group and moves integrally with the third lens group. 11. .