JP2020106681A - High-magnification zoom lens and image capturing device - Google Patents

Abstract

To provide a high-magnification zoom lens comprising multiple lens groups, which features sufficient consideration given to simplification of the mechanical structure by appropriately setting power distribution and displacement of the lens groups, is extremely compact, and offers high optical performance, and to provide an image capturing device having the same.SOLUTION: A zoom lens provided herein comprises at least a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, a fourth lens group having negative refractive power, a fifth lens group having positive refractive power, a sixth lens group having negative refractive power, and a seventh lens group having negative refractive power, in order from the object side, and is configured such that distances between adjacent lens groups change while zooming, The zoom lens satisfies predetermined conditional expressions. An image capturing device having such zoom lens is also provided herein.SELECTED DRAWING: Figure 1

Description

The present invention relates to a high magnification zoom lens and an image pickup apparatus, and more particularly to a high magnification zoom lens and an image pickup apparatus suitable for an image pickup apparatus such as a digital still camera or a digital video camera using a solid-state image pickup element such as CCD or CMOS. ..

2. Description of the Related Art Conventionally, image pickup apparatuses using solid-state image pickup devices such as digital still cameras and digital video cameras have been widely used. As such an image pickup device, there are various types such as a digital still camera, a digital video camera, a broadcast camera/film camera, a surveillance camera, and a vehicle-mounted camera.
Along with the high integration of the light-receiving element that constitutes the solid-state imaging device, the functionalization and miniaturization of any imaging device have been advanced. On the other hand, due to high integration of light receiving elements, the light receiving area of each light receiving element is becoming smaller. Therefore, higher performance is required for the image pickup optical system of the image pickup apparatus. Along with high performance of the imaging optical system, downsizing and high zoom ratio are also strongly demanded.

Conventionally, a multi-group zoom lens including seven or more lens groups is known as a so-called positive-leading type zoom lens including a lens group having a positive power on the most object side (for example, Patent Document 1). See 1.). Since such a zoom lens has a high degree of freedom in moving each lens group during zooming, it is easy to achieve high zooming, and it is easy to suppress variation in aberrations over the entire zoom range. A high zoom lens can be obtained.

On the other hand, in a multi-group zoom lens, the cam structure is likely to be complicated, so it is necessary to appropriately set the movement amount of each lens group by appropriately setting the power arrangement of each lens group. Particularly, in the positive-leading type zoom lens, mainly the second lens group has a large zoom ratio. However, if the variable magnification load of the second lens group is too large, the amount of movement of the first lens group becomes large, and a structure is required in which the cam barrel is divided into two stages and extended. Therefore, it becomes difficult to reduce the size of the lens barrel.
In order to achieve both miniaturization and high performance in a zoom lens having a high zoom ratio, it is necessary to appropriately set the imaging magnification, lens configuration, etc. in addition to the power arrangement of each lens group.

JP, 2016-080877, A JP, 2005-215438, A JP, 2018-022058, A

The zoom lens of Example 1 of Patent Document 1 is composed of seven groups of positive, negative, positive, negative, positive, negative, and negative having the same structure as the present invention, and provides a zoom lens with a zoom ratio of about 4 times. ing.
However, since the zoom lens has a large zooming load on the second lens group and a large amount of movement of the first lens group with respect to the zoom ratio, it is difficult to reduce the size of the lens barrel in response to further high zooming. is there.

The zoom lens of Example 1 of Patent Document 2 is composed of seven groups of positive, negative, positive, negative, positive, negative, and negative having the same structure as the present invention, and provides a zoom lens with a zoom ratio of about 7 times. ing.
However, since the negative combined refractive power of the rear group (the sixth lens group and the seventh lens group) is weak,
Telephoto ratio = total optical length at telephoto end/focal length of entire system at telephoto end is large, and miniaturization has not been achieved. Further, during focusing, since the three lenses of the fifth lens group and the three lenses of the sixth lens group are driven by the floating system, the focus weight is heavy and it is difficult to downsize the AF drive unit.

The zoom lenses of Example 3 and Example 4 of Patent Document 3 are composed of 8 groups of positive, negative, positive, negative, positive, negative, negative, and positive, and each have a zoom ratio of 7.1 times (Example 3 ), 8.6 times (Example 4) zoom lens.
However, the zoom lens of Patent Document 3, like the zoom lens of Patent Document 2, has a weak negative composite refractive power of the rear group (the sixth lens group to the eighth lens group), and therefore has a large telephoto ratio and is small in size. Is insufficient. Further, since the positive refractive power of the fifth lens group located on the objective side of the sixth lens group, which is the focus lens group, is weak, downsizing of the focus group is insufficient.

(Purpose of the invention)
The present invention has been made in view of the above-mentioned problems of the conventional high-variability zoom lens, and by appropriately setting the power distribution and the movement amount of each lens group even though the zoom lens has a multi-group configuration. It is an object of the present invention to provide a zoom lens having a high zoom ratio, which is extremely small in size and has high optical performance, with due consideration given to simplification of a mechanical structure, and an imaging device having the zoom lens.

The zoom lens according to the present invention,
In order from the object side, the first lens group having a positive refractive power, the second lens group having a negative refractive power, the third lens group having a positive refractive power, the fourth lens group having a negative refractive power, and the positive lens group Is a zoom lens which has at least a fifth lens group having a refractive power of, a sixth lens group having a negative refractive power, and a seventh lens group having a negative refractive power, and in which a distance between adjacent lens groups changes during zooming. In addition, the zoom lens is characterized by satisfying the following conditional expression.
0.3 ≤ f5 / fw ≤ 1.1 (1)
1.7 ≤ f1 / fw ≤ 8.0 (2)
However,
f1: focal length of the first lens group f5: focal length of the fifth lens group fw: focal length of the entire zoom lens system at the wide-angle end

The imaging device according to the present invention is
An image pickup apparatus comprising: the zoom lens; and an image pickup device that converts an optical image formed by the zoom lens into an electric signal on an image plane side of the zoom lens.

According to the present invention, even though the zoom lens has a multi-group structure, the power distribution and movement amount of each lens group are appropriately set, so that the mechanical structure is sufficiently simplified, and the size and size are very high. It is possible to configure a zoom lens having a high zoom ratio having optical performance and an imaging device having the zoom lens.

1 is a lens optical diagram of a zoom lens according to Example 1 of the present invention in a wide-angle end state. FIG. 6 is a spherical aberration diagram, an astigmatism diagram, and a distortion diagram at the time of focusing at infinity in the wide-angle end state of the first example of the zoom lens according to the present invention. FIG. 5 is a spherical aberration diagram, an astigmatism diagram, and a distortion diagram when focusing on infinity in the intermediate focal length state of the first example of the zoom lens according to the present invention. 2 is a lens configuration diagram of an optical system according to FIG. FIG. 5 is a spherical aberration diagram, an astigmatism diagram, and a distortion diagram when focusing on infinity in the telephoto end state of the first example of the zoom lens according to the present invention. FIG. 6 is a lens optical diagram in a wide-angle end state of a second example of the zoom lens according to the present invention. FIG. 9 is a spherical aberration diagram, an astigmatism diagram, and a distortion diagram at the time of focusing at infinity in the wide-angle end state of the second example of the zoom lens according to the present invention. FIG. 16 is a spherical aberration diagram, an astigmatism diagram, and a distortion diagram when focusing on infinity in the intermediate focal length state of the second example of the zoom lens according to the present invention. 2 is a lens configuration diagram of an optical system according to FIG. FIG. 9 is a spherical aberration diagram, an astigmatism diagram, and a distortion diagram at the time of focusing at infinity in the telephoto end state of the second example of the zoom lens according to the present invention. FIG. 9 is a lens optical diagram in a wide-angle end state of a third example of the zoom lens according to the present invention. FIG. 16 is a spherical aberration diagram, an astigmatism diagram, and a distortion diagram at the time of focusing at infinity in the wide-angle end state of the third example of the zoom lens of the present invention. FIG. 16 is a spherical aberration diagram, an astigmatism diagram, and a distortion diagram at the time of focusing at infinity in the intermediate focal length state of the third example of the zoom lens of the present invention. 2 is a lens configuration diagram of an optical system according to FIG. FIG. 13 is a spherical aberration diagram, an astigmatism diagram, and a distortion diagram when focusing on infinity in the telephoto end state of the third example of the zoom lens according to the present invention; FIG. 13 is a lens optical diagram in a wide-angle end state of a fourth example of the zoom lens according to the present invention. FIG. 17 is a spherical aberration diagram, an astigmatism diagram, and a distortion diagram at the time of focusing at infinity in the wide-angle end state of the fourth example of the zoom lens according to the present invention. FIG. 19 is a spherical aberration diagram, an astigmatism diagram, and a distortion diagram at the time of focusing at infinity in the intermediate focal length state of the fourth example of the zoom lens according to the present invention. 2 is a lens configuration diagram of an optical system according to FIG. FIG. 16 is a spherical aberration diagram, an astigmatism diagram, and a distortion diagram at the time of focusing at infinity in the telephoto end state of the fourth example of the zoom lens according to the present invention. It is a lens optical figure in the wide-angle end state of Example 5 of the zoom lens of the present invention. FIG. 16 is a spherical aberration diagram, an astigmatism diagram, and a distortion diagram when focusing on infinity in a wide-angle end state of a fifth example of the zoom lens according to the present invention. FIG. 19 is a spherical aberration diagram, an astigmatism diagram, and a distortion diagram at the time of focusing at infinity in the intermediate focal length state of the fifth example of the zoom lens of the present invention. 2 is a lens configuration diagram of an optical system according to FIG. FIG. 19 is a spherical aberration diagram, an astigmatism diagram, and a distortion diagram at the time of focusing at infinity in the telephoto end state of the fifth example of the zoom lens according to the present invention. It is a block diagram of the imaging device of the Example of this invention.

The zoom lens according to the present invention preferably satisfies at least one of the following conditional expressions or conditions.
Hereinafter, preferred embodiments of the present invention will be described.

The zoom lens according to the present invention,
In order from the object side, the first lens group having a positive refractive power, the second lens group having a negative refractive power, the third lens group having a positive refractive power, the fourth lens group having a negative refractive power, and the positive lens group At least a fifth lens group having a refracting power, a sixth lens group having a negative refracting power, and a seventh lens group having a negative refracting power, and are configured so that an interval between adjacent lens groups changes during zooming. It
In the zoom lens according to the present invention having such a configuration, by changing the distance between the adjacent lens groups during zooming, the degree of freedom during zooming is increased, high zooming is facilitated, and zooming is facilitated. It is possible to obtain a high-performance zoom lens with little aberration variation over time.

It should be noted that the zoom lens according to the present invention is not limited to the configuration including seven lens groups, and other components such as an eighth lens group having a positive or negative refractive power on the image side of the seventh lens group. The lens group may be included. By increasing the number of lens groups constituting the zoom lens according to the required performance, it is possible to increase the degree of freedom of aberration correction and obtain a higher performance zoom lens. However, if the number of lens groups that make up the zoom lens increases, it becomes difficult to reduce the size.
Further, from the viewpoint of reducing the telephoto ratio, it is preferable that the lens group arranged on the image side of the seventh lens group is a lens group having a positive refracting power as a whole. With such a configuration, it becomes easy to increase the negative combined refractive power of the sixth lens group and the seventh lens group, the amount of movement of each lens group can be reduced, and the total length at the telephoto end can be shortened. Can be realized.
Further, in order to avoid complication of the cam structure, it is preferable that the lens unit provided on the image side of the seventh lens unit is fixed during zooming.

In the present invention, it is preferable that the first lens group moves toward the object side during zooming from the wide-angle end to the telephoto end. With such a configuration, it becomes easy to reduce the overall length of the wide-angle end.

Further, it is more preferable that all the lens groups from the first lens group to the seventh lens group are located on the object side at the telephoto end with respect to the position at the wide angle end. When all the lens groups move in the same direction, the cam structure can be simplified. Specifically, when all the lens groups move in the same direction, it becomes easy to arrange the cam grooves of the plurality of lens groups in one cam barrel, and the zoom lens having the multi-group configuration as in the present invention is Since the number of cam barrels can be reduced, the lens barrel can be downsized.
However, only the second lens group may be configured to move to the image side and then to the object side in zooming from the wide-angle end. With such a configuration, it becomes easy to favorably correct astigmatism and coma over the entire zoom range.

Further, in zooming from the wide-angle end to the telephoto end, the distance between the first lens group and the second lens group becomes large, the distance between the second lens group and the third lens group becomes small, and the third lens group and the fourth lens group. It is desirable that the distance between the fourth lens group and the fifth lens group becomes small and the distance between the fourth lens group and the fifth lens group becomes small. With such a configuration, it is possible to arrange the lens units so that the zooming action of each lens unit does not easily occur, and it is possible to achieve both high magnification and high performance.

The zoom lens according to the present invention preferably satisfies the following conditional expression (1).
0.3 ≤ f5 / fw ≤ 1.1 (1)
However,
f5: focal length of fifth lens group fw: focal length of the entire zoom lens system at the wide-angle end

Conditional expression (1) is a conditional expression for appropriately setting the ratio of the focal length of the zoom lens entire system to the focal length of the fifth lens group at the wide-angle end.

By satisfying the conditional expression (1), it is possible to reduce the overall length, achieve both optical performance, and simplify the mechanical structure.
If the lower limit of conditional expression (1) is exceeded, it becomes easy to reduce the overall length, but it becomes difficult to satisfactorily correct spherical aberration and coma.
If the upper limit of conditional expression (1) is exceeded, spherical aberration and coma will be easily corrected, but it will be difficult to shorten the back focus, and it will be difficult to reduce the overall length. Further, when focusing is performed with the sixth lens group, it is difficult to reduce the size of the focus group. Furthermore, the negative combined refracting power of the sixth lens group and the seventh lens group becomes relatively weak, and the amount of movement of each lens group increases, which makes it difficult to dispose the cam barrel and complicates the cam structure.

In order to further secure the effect of the invention, the upper limit of conditional expression (1) is preferably 1.05, more preferably 1.00, and even more preferably 0.95. The lower limit of conditional expression (1) is preferably 0.40, more preferably 0.45, and even more preferably 0.50.

The zoom lens according to the present invention preferably satisfies the following conditional expression (2).
1.7 ≤ f1 / fw ≤ 8.0 (2)
However,
f1: focal length of the first lens group

Conditional expression (2) is a conditional expression for appropriately setting the ratio of the focal length of the entire zoom lens system to the focal length of the first lens group at the wide-angle end.

By satisfying the conditional expression (2), it is possible to achieve both downsizing and widening of the zoom lens.
When the value goes below the lower limit of the conditional expression (2), the amount of movement of the first lens group can be reduced, so that the lens barrel can be downsized, but it becomes difficult to obtain a predetermined angle of view on the wide-angle side. Therefore, it becomes difficult to realize a zoom lens having a high zoom ratio. In order to obtain a predetermined angle of view at the wide-angle end, it is necessary to increase the negative refractive power of the second lens group, which makes it difficult to correct the field curvature.
If the upper limit of conditional expression (2) is exceeded, the amount of movement of the first lens group becomes large, which complicates the cam structure and makes it difficult to downsize the lens barrel.

In order to further secure the effect of the invention, the upper limit of conditional expression (2) is preferably 7.0, more preferably 6.5, and further preferably 6.0. The lower limit of conditional expression (2) is preferably 2.0, more preferably 2.5, and even more preferably 3.0.

The zoom lens according to the present invention desirably satisfies the following conditional expression (3).
-0.24 ≤ f6it / ft ≤ -0.02 (3)
However,
f6it: Composite focal length from the sixth lens group to the most image side lens group at the telephoto end ft: Focal length of the entire zoom lens system at the telephoto end

Conditional expression (3) is a conditional expression for appropriately setting the ratio of the combined focal length from the sixth lens unit at the telephoto end to the lens unit closest to the image side and the focal length of the entire zoom lens system at the telephoto end. is there.

By satisfying conditional expression (3), the zoom lens according to the present invention can achieve both miniaturization and high performance of the lens barrel of the zoom lens and simplification of the cam structure.
If the lower limit of conditional expression (3) is exceeded, the negative combined refracting power of the lens unit closest to the image side from the sixth lens unit becomes relatively weak. Since the load is reduced and the variable power contribution to the second lens group is increased, the moving amount of the first lens group is increased and it becomes difficult to reduce the total length at the telephoto end. Further, since the moving amount of the first lens group increases, the cam structure becomes complicated and it becomes difficult to downsize the lens barrel.
If the upper limit of conditional expression (3) is exceeded, as the negative combined refractive power of the sixth lens group to the most image-side lens group becomes relatively strong, the positive power of the third lens group to the fifth lens group increases. The refractive power becomes strong, and it becomes difficult to correct various aberrations with a small number of lenses.

In order to further secure the effect of the present invention, the upper limit of conditional expression (3) is preferably −0.05, more preferably −0.07, and even more preferably −0.10. The lower limit value of conditional expression (3) is preferably −0.22, and more preferably −0.20.

In the zoom lens according to the present invention, it is desirable that the fourth lens group or the sixth lens group be the focus group.
Since both the fourth lens group and the sixth lens group are lens groups in which the lens groups adjacent to the object side have a positive refractive power, it is easy to reduce the diameter of the focus group. Further, both the fourth lens group and the sixth lens group are composed of one single lens or one lens component, whereby the AF drive unit can be downsized and high-speed AF operation can be realized. At this time, one lens component includes a cemented lens and a compound aspherical lens having no air gap therebetween.

The zoom lens according to the present invention preferably satisfies the following conditional expression (4).
0.2 ≤ M1 / (Z x Y) ≤ 0.6 (4)
However,
M1: amount of movement of the first lens unit during zooming Z: zoom ratio (=ft/fw)
Y: Maximum image height

By satisfying the conditional expression (4), the amount of movement of the first lens unit during zooming can be optimized, and the cam structure can be simplified. Therefore, the size of the lens barrel can be reduced. At this time, the movement amount refers to the distance on the optical axis between the position at the wide-angle end and the position at the telephoto end.
If the lower limit of conditional expression (4) is exceeded, the amount of movement of the first lens group will be too small, and the zooming load of the image side lens group will be greater than that of the second lens group, making it difficult to correct aberrations with a small number of lenses. become.
If the upper limit of conditional expression (4) is exceeded, the amount of movement of the first lens group becomes too large, which complicates the cam structure and makes it difficult to downsize the lens barrel.

In order to further secure the effect of the present invention, the upper limit of conditional expression (4) is preferably 0.55, more preferably 0.50, and even more preferably 0.45.
The lower limit of conditional expression (4) is preferably 0.22, and more preferably 0.25.

The zoom lens according to the present invention desirably satisfies the following conditional expression (5).
3.1 ≦ oalw / fw ≦ 7.0 (5)
However,
oalw: Distance from the lens surface closest to the object to the image plane at the wide-angle end

The zoom lens according to the present invention can realize a zoom lens having a short overall length at the wide-angle end by satisfying the conditional expression (5).
If the lower limit of conditional expression (5) is exceeded, the overall length at the wide-angle end becomes too short, making it difficult to arrange a cam structure for moving out each lens group. Further, it becomes difficult to correct coma and chromatic aberration, especially at the wide-angle end, and it becomes difficult to secure desired optical performance.
If the upper limit of conditional expression (5) is exceeded, the overall length at the wide-angle end becomes long, which is contrary to the object of the present invention to reduce the overall length.

In order to further secure the effect of the present invention, the upper limit of conditional expression (5) is preferably 6.0, more preferably 5.4, and even more preferably 5.2.
The lower limit value of conditional expression (5) is preferably 3.3, more preferably 3.5, and further preferably 3.8.

The zoom lens according to the present invention desirably satisfies the following conditional expression (6).
0.3 ≤ f5 / f3 ≤ 1.2 (6)
However,
f3: focal length of the third lens group

Conditional expression (6) is a conditional expression for appropriately setting the ratio of the focal length of the fifth lens group to the focal length of the third lens group.

By satisfying the conditional expression (6), it becomes easy to downsize the lens barrel and to secure the peripheral light amount especially at the wide-angle end.
When the lower limit of conditional expression (6) is exceeded, the aperture diameter becomes small, and the aperture unit can be easily downsized, which contributes to downsizing of the lens barrel. On the other hand, at the wide-angle end, the rear lens group, that is, the lens group arranged on the image side from the fifth lens group, has a large diameter, so that it becomes difficult to secure the peripheral light amount.
If the upper limit of conditional expression (6) is exceeded, it becomes easier to secure the amount of peripheral light at the wide-angle end, but since the diaphragm diameter becomes large, the diaphragm unit becomes large in diameter, making it difficult to downsize the lens barrel.

In order to further secure the effect of the invention, the upper limit of conditional expression (6) is preferably 1.1, more preferably 1.0, and further preferably 0.9.
The lower limit of conditional expression (6) is preferably 0.4, and more preferably 0.5.

The zoom lens according to the present invention preferably satisfies the following conditional expression (7).
0.6 ≤ f35w / fw ≤ 1.5 (7)
However,
f35w: Composite focal length from the third lens group to the fifth lens group at the wide-angle end

Conditional expression (7) is a conditional expression for appropriately setting the ratio of the combined focal length from the third lens group to the fifth lens group at the wide-angle end and the focal length of the entire zoom lens system at the wide-angle end.

By satisfying conditional expression (7), it is possible to reduce the total length and achieve optical performance at the same time.
If the lower limit of conditional expression (7) is exceeded, it becomes easy to reduce the overall length, but it becomes difficult to satisfactorily correct various aberrations (spherical aberration, coma, field curvature) over the entire zoom range.
If the upper limit of conditional expression (7) is exceeded, the total length at the wide-angle end becomes long and the amount of movement of each lens group also increases, making it difficult to downsize the lens barrel.

In order to further secure the effect of the present invention, the upper limit of conditional expression (7) is preferably 1.3, more preferably 1.1, and even more preferably 1.0.
The lower limit of conditional expression (7) is preferably 0.70, more preferably 0.75, and even more preferably 0.80.

The zoom lens according to the present invention preferably satisfies the following conditional expression.
1.3 ≤ β6it / β6iw ≤ 2.2 (8)
However,
β6it: Composite lateral magnification from the sixth lens group at the telephoto end to the lens group closest to the image side β6iw: Combined lateral magnification from the sixth lens group at the wide angle end to the lens group closest to the image side

The conditional expression (8) is a conditional expression for appropriately setting the zoom ratio from the sixth lens group to the lens group closest to the image side.

By satisfying the conditional expression (8), the zooming load of the second lens group can be reduced, so that the amount of movement of each lens group during zooming can be reduced and the lens barrel can be downsized.

If the lower limit of conditional expression (8) is exceeded, the variable magnification load from the sixth lens group to the lens group closest to the image side will decrease, so it is necessary to earn a variable magnification ratio mainly with the second lens group. It will be difficult to reduce the total length.
If the upper limit of conditional expression (8) is exceeded, it is advantageous for downsizing the entire length, but the telephoto ratio becomes too small, and it becomes difficult to correct aberrations with a small number of lenses.

In order to further secure the effect of the present invention, the upper limit of conditional expression (8) is preferably 2.0, more preferably 1.9, and even more preferably 1.8.
The lower limit of conditional expression (8) is preferably 1.4, and more preferably 1.5.

The zoom lens according to the present invention preferably satisfies the following conditional expression (9).
-1.6 ≤ f6iw / fw ≤ -0.4 (9)
However,
f6iw: Composite focal length from the sixth lens unit at the wide-angle end to the lens unit closest to the image side

Conditional expression (9) is a conditional expression for appropriately setting the ratio of the combined focal length from the sixth lens unit at the wide-angle end to the lens unit closest to the image side and the focal length of the entire zoom lens system at the wide-angle end. is there.

By satisfying conditional expression (9), it is possible to achieve both miniaturization and high performance of the lens barrel of the zoom lens and simplification of the cam structure.
If the lower limit of conditional expression (9) is exceeded, the negative combined refracting power of the lens unit closest to the image side from the sixth lens unit becomes relatively weak. The double load is reduced, and the variable power contribution to the second lens group is increased. As a result, the amount of movement of the first lens group increases, making it difficult to reduce the overall length at the telephoto end. Further, since the moving amount of the first lens group increases, the cam structure becomes complicated and it becomes difficult to downsize the lens barrel.
If the upper limit of conditional expression (9) is exceeded, the negative combined refractive power of the sixth lens group to the most image-side lens group becomes relatively strong, and the lens groups from the third lens group to the fifth lens group. The positive refracting power of becomes strong, and it becomes difficult to correct various aberrations with a small number of lenses.

In order to further secure the effect of the present invention, the upper limit of conditional expression (9) is preferably −0.50, more preferably −0.55, and even more preferably −0.60.
The lower limit of conditional expression (9) is preferably −1.5, more preferably −1.4, and even more preferably −1.3.

In the zoom lens according to the present invention, it is preferable that the third lens group, the fifth lens group, and the seventh lens group each move along the same locus during zooming. By making the movement loci of the third lens group, the fifth lens group, and the seventh lens group equal, the mechanical structure for moving the third lens group, the fifth lens group, and the seventh lens group is made into an integral structure. You can With this integrated structure, the cam structure can be simplified, so that the lens barrel can be easily downsized. In addition, since relative decentering of the third lens group, the fifth lens group, and the seventh lens group that may occur during zooming can be suppressed to a small level, it is possible to suppress deterioration of optical performance due to manufacturing errors as much as possible.
The lens groups that move along the same movement locus may be only the third lens group and the fifth lens group or only the fifth lens group and the seventh lens group, and in those cases, the same as above. The effect of is obtained.

In the zoom lens according to the present invention, it is desirable that the aperture stop be arranged adjacent to the objective side of the third lens group.
By arranging the aperture stop in this way, it becomes easy to arrange the diaphragm unit and the AF drive unit without interfering with each other, and it is possible to avoid complication of the mechanical structure.

In the zoom lens according to the present invention, it is preferable that the most object-side lens of the fifth lens group have at least one aspherical surface. With such a configuration, it is possible to satisfactorily correct the balance between the coma aberration on the wide angle side and the spherical aberration on the telephoto side.

An image pickup apparatus according to the present invention includes the zoom lens described above, and an image pickup element that converts an optical image formed by the zoom lens into an electric signal on the image plane side of the zoom lens.
In the image pickup device of the image pickup apparatus according to the present invention, an image having a high degree of optical performance is converted into an electrical signal, and the image formation light beam is made incident on the light receiving surface substantially vertically not only at the center of the field of view but also at the peripheral part of the field of view. By doing so, it is possible to suppress a decrease in photoelectric conversion efficiency in the peripheral portion of the visual field and form a preferable image formation signal.

(Example)
Hereinafter, a zoom lens according to the present invention and an image pickup apparatus including the same will be described with reference to numerical examples and attached drawings.

Numerical examples to which specific numerical values of the optical system according to the present invention are applied will be described. In the table, f is the focal length of the entire system, FNo. is the F number, ω is the half angle of view (°), Y is the maximum image height, r is the radius of curvature, d is the lens thickness or lens interval, and nd is at the d line. Refractive index, vd indicates the Abbe number at the d-line. The surface described as S beside each surface number represents an aperture stop, and the surface described as ASPH represents a surface having an aspherical shape.
Further, each aspherical shape has a height H perpendicular to the optical axis, a displacement amount in the optical axis direction at the height H when the surface apex is the origin X(H), and a curvature at the surface apex C, When the conical coefficient is K, the 4th order, the 6th order, the 8th order, the 10th order, and the 12th order aspherical surface coefficients are A4, A6, A8, A10, and A12, respectively, they are expressed by the following aspherical expressions.
※ aspheric expression ^{X (H) = CH 2 /} [1+ {1- (1 + Κ) · C 2 H 2} 1/2] + A4 · H 4 + A6 · H 6 + A8 · H 8 + A10 · H 10 + A12 · H 12

In the longitudinal aberration diagrams (FIGS. 2 to 4, FIG. 6 to FIG. 8, FIG. 10 to FIG. 12, FIG. 14 to FIG. 16 and FIG. 18 to FIG. 20) of the respective examples, spherical aberration (SA( mm)), astigmatism (AST (mm)), and distortion (DIS (%)). In the spherical aberration diagram, the vertical axis represents the F number (indicated by FNo. in the figure), the solid line is the d line (587.56 nm), the broken line is the C line (656.28 nm), and the alternate long and short dash line is the g line (435. 84 nm). In the astigmatism diagram, the vertical axis represents the angle of view (indicated by ω in the figure), the solid line represents the sagittal image plane (indicated by ds in the figure), and the broken line represents the meridional image plane (indicated by dm in the figure). It is a characteristic. In the distortion diagram, the vertical axis represents the half angle of view (indicated by ω in the figure).

(First embodiment)
The first embodiment of the zoom lens according to the present invention includes, as shown in FIG. 1, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a positive refractive power in order from the object side. Third lens group G3 having a power, fourth lens group G4 having a negative refractive power, fifth lens group G5 having a positive refractive power, sixth lens group G6 having a negative refractive power, seventh lens group having a negative refractive power It is composed of G7. A cover glass CG is arranged on the object plane side of the image plane IP.
In zooming from the wide-angle end to the telephoto end, as shown in FIG. 1, the first lens group G1 moves to the object side, and the second lens group G2 first moves to the image side and then to the object side. The third lens group G3 moves to the object side, the fourth lens group G4 moves to the object side, the fifth lens group G5 moves to the object side, the sixth lens group G6 moves to the object side, and the seventh lens The group G7 moves to the object side. In zooming, the third lens group G3, the fifth lens group G5, and the seventh lens group G7 move on the same trajectory.
In focusing from an object at infinity to an object at a short distance, the sixth lens group G6 moves to the image side.

The aperture stop S is arranged adjacent to the object side of the third lens group G3.

The first lens group G1 is composed of, in order from the object side, a negative meniscus lens L1 having a convex surface facing the object side, a cemented lens with a biconvex lens L2, and a positive meniscus lens L3 having a convex surface facing the object side.
The second lens group G2 includes, in order from the object side, a negative meniscus lens L4 having a convex surface directed toward the object side, a biconcave lens L5, a biconvex lens L6, and a negative meniscus lens L7 having a convex surface directed toward the image side. Composed. The negative meniscus lens L4 is a glass mold type aspherical lens having an aspherical surface on the object side.
The third lens group G3 is composed of, in order from the object side, a positive meniscus lens L8 having a convex surface directed toward the object side, a biconvex lens L9, and a cemented lens composed of a negative meniscus lens L10 having a convex surface directed toward the object side and a biconvex lens L11. It
The fourth lens group G4 is composed of a biconcave lens L12. The biconcave lens L12 is a composite resin type aspherical lens in which a composite resin film molded in an aspherical shape is attached to the object side surface.
The fifth lens group G5 is composed of, in order from the object side, a biconvex lens L13, and a cemented lens of a negative meniscus lens L14 having a convex surface facing the object side and a biconvex lens L15. The biconvex lens L13 is a glass mold type aspherical lens whose both surfaces are aspherical.
The sixth lens group G6 is composed of a negative meniscus lens L16 having a convex surface directed toward the object side. The negative meniscus lens L16 is a glass mold type aspherical lens whose both surfaces are aspherical.
The seventh lens group G7 is composed of, in order from the object side, a biconvex lens L17, a biconcave lens L18, and a negative meniscus lens L19 having a convex surface directed toward the image side.

When the zoom lens vibrates due to camera shake or the like, at least one of the lenses forming the zoom lens is set as an image stabilization group, and the image stabilization is performed by decentering the image stabilization group. It is preferable to carry out. In particular, by moving any of the biconcave lens L12, the negative meniscus lens L16, or the biconcave lens L18 in the direction perpendicular to the optical axis, the image position can be corrected and the image blur caused by the vibration can be corrected.

The optical data of the first example is shown below.
Table 1 shows a specification table of the first embodiment.
(Table 1)
Wide-angle end Mid-telephoto end
f 28.7936 75.0289 193.9307
FNo. 2.8965 4.1889 5.7781
ω 37.6195 15.3512 6.1472
Y 21.6330 21.6330 21.6330

Table 2 shows the lens data of the first example.
(Table 2)
Surface number rd nd νd
Object plane ∞ d( 0)
1 126.8033 1.2000 1.85478 24.80
2 73.1163 6.5498 1.49700 81.61
3 -619.9628 0.2000
4 57.8673 4.7502 1.59349 67.00
5 168.1327 d( 5)
6 ASPH 73.0270 1.1000 1.87070 40.73
7 20.1788 6.5245
8 -59.9309 0.8000 1.87070 40.73
9 32.6271 6.1879 1.84666 23.78
10 -33.8219 0.9000 1.80420 46.50
11 -633.2189 d(11)
12 S ∞ 1.2000
13 34.8967 2.5748 1.85478 24.80
14 105.2664 0.2143
15 48.7916 2.8950 1.72916 54.67
16 -207.3456 0.2000
17 101.3163 0.9000 1.80809 22.76
18 29.9068 3.5853 1.49700 81.61
19 -132.7415 d(19)
20 ASPH -23.7077 0.2468 1.51460 49.96
21 -25.7724 0.8000 1.85150 40.78
22 65.2251 d(22)
23 ASPH 23.0080 6.3068 1.69350 53.18
24 ASPH -48.1474 0.2000
25 37.0746 0.8000 1.91082 35.25
26 16.3655 6.4374 1.49700 81.61
27 -35.1960 d(27)
28 ASPH 79.0659 0.9000 1.59201 67.02
29 ASPH 19.9423 d(29)
30 36.6023 6.3766 1.67270 32.10
31 -45.2 833 0.2000
32 -303.8734 0.9000 1.85 150 40.78
33 40.0745 6.5841
34 -21.0548 1.0000 1.72916 54.68
35 -52.1735 d(35)
36 ∞ 2.5000 1.51680 64.20
37 ∞ 1.0000
Image plane ∞

Table 3 shows the lens interval data of the first example.
(Table 3)
Variable interval
Wide-angle mid-telephoto Wide-angle mid-telephoto
d(0) ∞ ∞ ∞ 165.7499 340.7231 610.7499
d(5) 0.8000 24.6717 48.0431 0.8000 24.6717 48.0431
d(11) 24.4154 10.1212 2.1272 24.4154 10.1212 2.1272
d(19) 2.2954 4.0353 6.4036 2.2954 4.0353 6.4036
d(22) 5.2082 3.4678 1.1000 5.2082 3.4678 1.1000
d(27) 1.3034 2.3598 1.4441 2.8006 5.0953 8.0146
d(29) 12.6942 11.6380 12.5536 11.1970 8.9024 5.9831
d(35) 13.4999 28.9498 43.5451 13.4999 28.9498 43.5451

Table 4 shows the focal lengths of the lens groups of the first example.
(Table 4)
Group number focal length
G1 106.0065
G2 -21.9002
G3 28.3494
G4 -20.7806
G5 19.0830
G6 -45.3040
G7 -144.1356

Table 5 shows the aspherical surface coefficients of the first embodiment.
(Table 5)
Aspheric coefficient (Aspheric coefficient not shown is 0.00000.)
Surface number K A4 A6 A8 A10 A12
6 0.0000 -9.86089E-07 -9.19169E-10 -2.48794E-12 1.49982E-15 0.00000E+00
20 -0.1591 3.73272E-05 -9.02045E-08 9.87967E-10 -7.53595E-12 2.38762E-14
23 0.3924 -2.16911E-05 8.68108E-09 1.11227E-09 -1.16883E-11 4.79637E-14
24 0.0000 3.27128E-05 -1.04498E-07 2.33175E-09 -2.01761E-11 7.62655E-14
28 0.0000 -2.55954E-05 3.56502E-07 -1.70180E-09 -6.24255E-12 6.45296E-14
29 0.0000 -3.14993E-05 4.15457E-07 -2.60403E-09 -9.27673E-13 5.04098E-14

(Second embodiment)
The second embodiment of the zoom lens according to the present invention is, as shown in FIG. 5, 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 positive refractive power. Third lens group G3, fourth lens group G4 with negative refractive power, fifth lens group G5 with positive refractive power, sixth lens group G6 with negative refractive power, seventh lens group G7 with negative refractive power Composed of. A cover glass CG is arranged on the object plane side of the image plane IP.

In zooming from the wide-angle end to the telephoto end, as shown in FIG. 5, the first lens group G1 moves to the object side, and the second lens group G22 first moves to the image side and then to the object side. The third lens group G3 moves to the object side, the fourth lens group G4 moves to the object side, the fifth lens group G5 moves to the object side, the sixth lens group G6 moves to the object side, and the seventh lens The group G7 moves to the object side. In zooming, the third lens group G3, the fifth lens group G5, and the seventh lens group G7 move on the same orbit.
In focusing from an object at infinity to a near object, the fourth lens group G4 moves to the object side.

The aperture stop S is arranged adjacent to the object side of the third lens group G3.

The first lens group G1 is composed of, in order from the object side, a negative meniscus lens L1 having a convex surface facing the object side, a cemented lens with a biconvex lens L2, and a positive meniscus lens L3 having a convex surface facing the object side.
The second lens group G2 is composed of, in order from the object side, a negative meniscus lens L4 having a convex surface facing the object side, a cemented lens of a biconcave lens L5 and a biconvex lens L6, and a negative meniscus lens L7 having a convex surface facing the image side. It The negative meniscus lens L4 is a composite resin type aspherical lens in which a composite resin film molded in an aspherical shape is attached to the object side surface.
The third lens group G3 is composed of, in order from the object side, a biconvex lens L8, a biconvex lens L9, and a cemented lens of a negative meniscus lens L10 having a convex surface directed toward the image side.
The fourth lens group G4 is composed of a biconcave lens L11. The biconcave lens L11 is a composite resin type aspherical lens in which a composite resin film molded in an aspherical shape is attached to the object side surface.
The fifth lens group G5 is composed of, in order from the object side, a biconvex lens L12, and a cemented lens of a negative meniscus lens L13 having a convex surface directed toward the object side and a biconvex lens L14. The biconvex lens L12 is a glass mold type aspherical lens whose both surfaces are aspherical.
The sixth lens group G6 is composed of a negative meniscus lens L15 having a convex surface directed toward the object side. The negative meniscus lens L15 is a glass mold type aspherical lens whose both surfaces are aspherical.
The seventh lens group G7 is composed of, in order from the object side, a biconvex lens L16, a biconcave lens L17, and a negative meniscus lens L18 having a convex surface directed toward the image side.

When the zoom lens vibrates due to camera shake or the like, at least one of the lenses forming the zoom lens is set as an image stabilization group, and the image stabilization is performed by decentering the image stabilization group. It is preferable to carry out. In particular, by moving any of the biconcave lens L11, the negative meniscus lens L15, or the biconcave lens L17 in the direction perpendicular to the optical axis, the image position can be corrected and the image blur caused by the vibration can be corrected.

The optical data of the second embodiment are shown below.
Table 6 shows a specification table of the second embodiment.
(Table 6)
Wide-angle end Mid-telephoto end
f 28.8088 74.9934 193.9843
FNo. 3.5613 4.4997 5.7497
ω 38.9265 15.4642 6.1181
Y 21.6330 21.6330 21.6330

Table 7 shows the lens data of the second example.
(Table 7)
Surface number rd nd νd
Object plane ∞ d( 0)
1 149.3109 1.2000 1.85478 24.80
2 76.0948 7.1171 1.49700 81.61
3 -1072.3665 0.2000
4 66.0148 5.5600 1.59349 67.00
5 283.4193 d( 5)
6 ASPH 131.1407 0.1500 1.51460 49.96
7 117.0450 1.1000 1.90366 31.31
8 22.8085 5.5879
9 -107.5361 0.8000 1.83481 42.72
10 24.0970 5.5879 1.84666 23.78
11 -64.4752 0.6867
12 -39.5818 0.9000 1.80420 46.50
13 -185.3667 d(13)
14 S ∞ 1.2000
15 33.8846 3.2667 1.80000 29.84
16 -332.6257 0.2000
17 5000.0000 3.7611 1.57501 41.50
18 -24.4679 0.9000 1.83400 37.21
19 -43.8545 d(19)
20 ASPH -22.9591 0.1500 1.51460 49.96
21 -26.0428 0.8000 1.87070 40.73
22 53.6491 d(22)
23 ASPH 28.6779 4.6565 1.69350 53.18
24 ASPH -36.5598 0.2000
25 34.5392 0.8000 1.92119 23.96
26 19.3565 7.5164 1.49700 81.61
27 -48.5874 d(27)
28 ASPH 57.6247 0.9000 1.68893 31.16
29 ASPH 25.8168 d(29)
30 40.1744 9.5000 1.64769 33.79
31 -25.7354 0.2000
32 -28.7174 0.9000 1.87070 40.73
33 120.1990 5.7951
34 -16.0000 1.0000 1.72916 54.67
35 -26.9906 d(35)
36 ∞ 2.5000 1.51680 64.20
37 ∞ 1.0000
Image plane ∞

Table 8 shows the lens spacing of the second embodiment.
(Table 8)
Variable interval
Wide-angle mid-telephoto Wide-angle mid-telephoto
d(0) ∞ ∞ ∞ 365.0001 336.8530 605.0002
d(5) 1.1522 30.8984 55.1293 1.1522 30.8984 55.1293
d(13) 22.1323 7.0681 1.6849 22.1323 7.0681 1.6849
d(19) 2.4416 3.6056 7.1001 1.4943 1.8713 4.1187
d(22) 5.3399 4.1757 0.6812 6.2872 5.9101 3.6627
d(27) 1.2932 4.9795 8.9510 1.2932 4.9795 8.9510
d(29) 12.8482 9.1620 5.1904 12.8482 9.1620 5.1904
d(35) 15.6570 29.1223 42.1273 15.6570 29.1223 42.1273

Table 9 shows the focal lengths of the lens groups of the second example.
(Table 9)
Group number focal length
G1 118.8991
G2 -22.4091
G3 29.9675
G4 -18.9990
G5 18.6329
G6 -68.6819
G7 -97.2914

Table 10 shows the aspherical surface coefficients of the second embodiment.
(Table 10)
Aspheric coefficient (Aspheric coefficient not shown is 0.00000.)
Surface number K A4 A6 A8 A10 A12
6 0.0000 8.87003E-07 2.06774E-09 -1.18068E-11 2.04323E-14 0.00000E+00
20 1.7375 4.27377E-05 5.59066E-08 5.40110E-10 -1.90435E-12 1.76795E-14
23 0.3977 -1.92166E-05 -8.94668E-09 5.51734E-10 -5.49188E-12 1.83133E-14
24 0.0000 9.06050E-06 -2.84346E-08 5.73029E-10 -4.90970E-12 1.56700E-14
28 0.0000 -2.00094E-05 1.97916E-07 -1.34790E-09 2.09962E-12 2.13721E-14
29 0.0000 -1.78331E-05 2.09037E-07 -1.29736E-09 5.07192E-13 3.57901E-14

(Third embodiment)
The third embodiment of the zoom lens according to the present invention, as shown in FIG. 9, has a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a positive refractive power in order from the object side. Third lens group G3 having a power, fourth lens group G4 having a negative refractive power, fifth lens group G5 having a positive refractive power, sixth lens group G6 having a negative refractive power, seventh lens group having a negative refractive power It is composed of G7. A cover glass CG is arranged on the object plane side of the image plane IP.

In zooming from the wide-angle end to the telephoto end, as shown in FIG. 9, the first lens group G1 moves to the object side, the second lens group G2 first moves to the image side, and then to the object side, The lens group G3 moves to the object side, the fourth lens group G4 moves to the object side, the fifth lens group G5 moves to the object side, the sixth lens group G6 moves to the object side, and the seventh lens group G7 moves to the object side. In zooming, the third lens group G3, the fifth lens group G5, and the seventh lens group G7 move on the same orbit.
Focusing from an object at infinity to a near object is performed by moving the sixth lens group G6 to the image side.

The aperture stop S is arranged adjacent to the object side of the third lens group G3.

The first lens group G1 is composed of, in order from the object side, a negative meniscus lens L1 having a convex surface facing the object side, a cemented lens with a biconvex lens L2, and a positive meniscus lens L3 having a convex surface facing the object side.
The second lens group G2 is composed of, in order from the object side, a negative meniscus lens L4 having a convex surface facing the object side, a biconcave lens L5, a biconvex lens L6, and a negative meniscus lens L7 having a convex surface facing the image side. The negative meniscus lens L4 is a glass mold type aspherical lens having an aspherical surface on the object side.
The third lens group G3 includes, in order from the object side, a positive meniscus lens L8 having a convex surface directed toward the object side, a positive meniscus lens L9 having a convex surface directed toward the object side, a negative meniscus lens L10 having a convex surface directed toward the object side, and a biconvex lens. It is composed of a cemented lens with L11. The positive meniscus lens L8 is a glass mold type aspherical lens whose both surfaces are aspherical.
The fourth lens group G4 is composed of, in order from the object side, a cemented lens of a biconcave lens L12 and a positive meniscus lens L13 having a convex surface facing the object side.
The fifth lens group G5 is composed of, in order from the object side, a cemented lens of a negative meniscus lens L14 having a convex surface facing the object side and a positive meniscus lens L15 having a convex surface facing the object side, and a biconvex lens L16. The biconvex lens L16 is a glass mold type aspherical lens whose both surfaces are aspherical.
The sixth lens group G6 is composed of a negative meniscus lens L17 having a convex surface directed toward the object side. The negative meniscus lens L17 is a glass mold type aspherical lens having an aspherical surface on the image side.
The seventh lens group G7 is composed of, in order from the object side, a biconvex lens L18, a biconcave lens L19, and a negative meniscus lens L20 having a convex surface directed toward the image side.
When the zoom lens vibrates due to camera shake or the like, at least one of the lenses forming the zoom lens is set as an image stabilization group, and the image stabilization is performed by decentering the image stabilization group. It is preferable to carry out. In particular, the image position is corrected by moving either the cemented lens of the biconcave lens L12 and the positive meniscus lens L13, the negative meniscus lens L17, or the biconcave lens L19 in the direction perpendicular to the optical axis, and the image accompanying the vibration is corrected. Blur can be corrected.

The optical data of the third example is shown below.
Table 11 shows a specification table of the third embodiment.
(Table 11)
Wide-angle end Mid-telephoto end
f 28.8003 75.0027 193.9288
FNo. 2.8982 4.5018 5.7528
ω 37.0367 15.3644 6.1210
Y 21.6330 21.6330 21.6330

Table 12 shows the lens data of the third example.
(Table 12)
Surface number rd nd νd
Object plane ∞ d( 0)
1 72.7418 1.2000 1.85478 24.80
2 55.0925 7.1178 1.49700 81.61
3 -2576.0254 0.2000
4 67.9905 3.3979 1.59349 67.00
5 131.2902 d( 5)
6 ASPH 81.8222 1.1000 1.87070 40.73
7 17.3549 7.3619
8 -46.9936 0.8000 1.87070 40.73
9 55.3112 0.1500
10 37.6438 6.1652 1.85478 24.80
11 -32.9640 0.9561
12 -26.2287 0.9000 1.83481 42.72
13 -101.7927 d(13)
14 S ∞ 1.2000
15 ASPH 37.1604 2.7113 1.69350 53.18
16 ASPH 132.8507 0.2000
17 38.9190 3.0811 1.60311 60.69
18 682.8 260 0.2000
19 42.5438 0.8000 1.80000 29.84
20 17.2829 5.3715 1.59282 68.62
21 -174.6671 d(21)
22 -85.1322 0.8000 1.78800 47.37
23 21.4134 2.9687 1.85478 24.80
24 58.4808 d(24)
25 51.7474 0.8000 1.90366 31.31
26 17.9175 2.8921 1.49700 81.61
27 43.1221 0.2000
28 ASPH 20.7365 5.6905 1.59201 67.02
29 ASPH -28.6011 d(29)
30 190.9486 0.9000 1.59201 67.02
31 ASPH 20.2337 d(31)
32 36.8017 7.0403 1.60342 38.03
33 -31.9447 0.2000
34 -58.6191 0.9000 1.88300 40.80
35 340.8507 4.3067
36 -24.4531 1.0000 1.80420 46.50
37 -104.9522 d(37)
38 ∞ 2.5000 1.51680 64.20
39 ∞ 1.0000
Image plane ∞

Table 13 shows the lens intervals of the third example.
(Table 13)
Variable interval
Wide-angle mid-telephoto Wide-angle mid-telephoto
d(0) ∞ ∞ ∞ 165.0002 341.3593 610.0000
d(5) 0.8000 21.8724 50.6988 0.8000 21.8724 50.6988
d(13) 24.8447 9.6041 1.7762 24.8447 9.6041 1.7762
d(21) 1.4907 4.5549 7.0064 1.4907 4.5549 7.0064
d(24) 6.6157 3.5515 1.1000 6.6157 3.5515 1.1000
d(29) 4.6632 4.9482 1.3034 6.2596 7.5604 7.6792
d(31) 8.9747 8.6898 12.3345 7.3783 6.0775 5.9587
d(37) 13.4998 31.3089 41.6697 13.4998 31.3089 41.6697

Table 14 shows the focal lengths of the lens groups of the third example.
(Table 14)
Group number focal length
G1 103.1709
G2 -19.9223
G3 27.1565
G4 -47.7441
G5 31.2329
G6 -38.3038
G7 -298.9440

Table 15 shows the aspherical surface coefficients of the third embodiment.
(Table 15)
Aspheric coefficient (Aspheric coefficient not shown is 0.00000.)
Surface number K A4 A6 A8 A10 A12
6 0.0000 1.11737E-06 7.19073E-10 -1.04952E-11 3.44628E-14 0.00000E+00
15 0.8177 -6.08206E-06 2.68573E-08 3.62072E-11 -1.38597E-13 5.64966E-15
16 0.0000 -1.55722E-06 3.17267E-08 1.05195E-10 -6.46114E-13 7.81993E-15
28 -0.4515 -1.96769E-05 3.02593E-09 1.65183E-10 -2.06130E-12 4.64386E-15
29 -1.4863 2.82074E-06 -4.69572E-08 1.82020E-10 -1.21460E-12 -4.72267E-16
31 0.0000 -9.57691E-06 7.26474E-09 2.57523E-10 -2.29565E-12 1.06894E-14

The fourth embodiment of the zoom lens according to the present invention, as shown in FIG. 13, sequentially from the object side, the first lens group G1 having a positive refractive power, the second lens group G2 having a negative refractive power, and the positive refractive power. Third lens group G3, fourth lens group G4 with negative refractive power, fifth lens group G5 with positive refractive power, sixth lens group G6 with negative refractive power, seventh lens group G7 with negative refractive power Composed of. A cover glass CG is arranged on the object plane side of the image plane IP.

In zooming from the wide-angle end to the telephoto end, the first lens group G1 moves to the object side, the second lens group G2 first moves to the image side and then to the object side, and the third lens group G3 moves to the object side. The fourth lens group G4 moves to the object side, the fifth lens group G5 moves to the object side, the sixth lens group G6 moves to the object side, and the seventh lens group G7 moves to the object side. ..
Focusing from an object at infinity to a near object is performed by moving the sixth lens group G6 to the image side.

The aperture stop S is arranged adjacent to the object side of the third lens group G3.

The first lens group G1 includes, in order from the object side, a negative meniscus lens L1 having a convex surface directed toward the object side, a cemented lens with a biconvex lens L2, and a biconvex lens L3.
The second lens group G2 is composed of, in order from the object side, a negative meniscus lens L4 having a convex surface directed toward the object side, a biconcave lens L5, a biconvex lens L6, and a negative meniscus lens L7 having a convex surface directed toward the image side. It The negative meniscus lens L4 is a glass mold type aspherical lens whose both surfaces are aspherical.
The third lens group G3 is composed of, in order from the object side, a biconvex lens L8, a positive meniscus lens L9 having a convex surface facing the object side, and a cemented lens of a biconvex lens L10 and a biconcave lens L11.
The fourth lens group G4 is composed of, in order from the object side, a cemented lens of a biconcave lens L12 and a positive meniscus lens L13 having a convex surface facing the object side. The biconcave lens L14 is a glass mold type aspherical lens having an aspherical surface on the object side.
The fifth lens group G5 is composed of, in order from the object side, a biconvex lens L14, and a cemented lens of a negative meniscus lens L15 having a convex surface directed toward the object side and a biconvex lens L16. The biconvex lens L14 is a glass mold type aspherical lens whose both surfaces are aspherical.
The sixth lens group G6 is composed of, in order from the object side, a cemented lens made up of a biconvex lens L17 and a biconcave lens L18. The biconcave lens L18 is a glass mold type aspherical lens having an aspherical surface on the image side.
The seventh lens group G7 includes, in order from the object side, a cemented lens of a biconcave lens L19 and a biconvex lens L20, a biconvex lens L21, a negative meniscus lens L22 having a convex surface directed toward the image side, and a negative meniscus lens having a convex surface directed toward the image side. It is composed of L23. The biconcave lens L19 is a composite resin type aspherical lens in which a composite resin film molded into an aspherical shape is attached to the object side surface.

When the zoom lens vibrates due to camera shake or the like, at least one of the lenses forming the zoom lens is set as an image stabilization group, and the image stabilization is performed by decentering the image stabilization group. It is preferable to carry out. Particularly, by moving either the cemented lens of the biconcave lens L12 and the positive meniscus lens L13, the cemented lens of the biconvex lens L17 and the biconcave lens L18, or the negative meniscus lens L22 in the direction perpendicular to the optical axis, the image position It is possible to correct the image blur caused by the vibration.

The optical data of the fourth example is shown below.
Table 16 shows a specification table of the fourth embodiment.
(Table 16)
Wide-angle end Mid-telephoto end
f 28.8049 130.0083 387.8306
FNo. 3.6008 6.2008 6.4916
ω 38.5769 9.0404 3.0410
Y 21.6330 21.6330 21.6330

Table 17 shows the lens data of the fourth example.
(Table 17)
Surface number rd nd νd
Object plane ∞ d( 0)
1 192.6617 1.3000 1.87070 40.73
2 95.9244 7.4083 1.43700 95.10
3 -554.2655 0.2000
4 94.2764 6.5301 1.49700 81.61
5 -7370.9991 d( 5)
6 ASPH 679.0773 1.3000 1.88202 37.22
7 ASPH 27.5984 6.8641
8 -73.8932 1.0000 1.88300 40.80
9 79.6776 0.1500
10 57.8945 7.0811 1.85478 24.80
11 -34.0424 1.0000 1.78590 44.20
12 -1463.4181 d(12)
13 S ∞ 1.0000
14 45.4512 3.4975 1.64850 53.02
15 -4514.9247 0.2825
16 44.0199 3.4681 1.60342 38.03
17 1022.8033 0.2000
18 68.1589 3.3302 1.49700 81.61
19 -132.0158 1.0000 1.92286 20.88
20 99.2304 d(20)
21 ASPH -71.0569 1.2000 1.77377 47.17
22 36.5603 2.6661 1.92119 23.96
23 92.3328 d(23)
24 ASPH 25.1199 4.9010 1.69350 53.18
25 ASPH -98.8550 0.1500
26 98.6246 1.0000 1.91082 35.25
27 17.1392 6.6649 1.59282 68.62
28 -64.0599 d(28)
29 204.9516 2.8807 1.62004 36.26
30 -53.7779 1.0000 1.59201 67.02
31 ASPH 29.8860 d(31)
32 ASPH -162.6004 0.2500 1.51460 49.96
33 -101.8172 1.0000 2.00100 29.13
34 20.1279 5.5899 1.59551 39.24
35 -486.2883 0.9292
36 40.1305 7.8732 1.76182 26.61
37 -36.3556 0.4110
38 -55.1244 1.0000 1.88300 40.80
39 -352.6208 3.1126
40 -32.6941 1.0000 1.69680 55.53
41 -459.9848 d(41)
42 ∞ 2.5000 1.51680 64.20
43 ∞ 1.0000
Image plane ∞

Table 18 shows the lens spacing of the fourth example.
(Table 18)
Variable interval
Wide-angle mid-telephoto Wide-angle mid-telephoto
d(0) ∞ ∞ ∞ 325.0000 480.3873 930.6798
d(5) 1.7332 50.3141 101.6060 1.7332 50.3141 101.6060
d(12) 46.5713 11.2573 1.8737 46.5713 11.2573 1.8737
d(20) 2.3437 3.9857 7.4130 2.3437 3.9857 7.4130
d(23) 10.3197 4.8164 1.2000 10.3197 4.8164 1.2000
d(28) 4.7875 8.3835 1.6036 5.8711 12.8913 14.9238
d(31) 5.0042 8.1145 16.2964 3.9206 3.6067 2.9762
d(41) 13.5000 42.0009 49.2670 13.5000 42.0009 49.2670

Table 19 shows the focal lengths of the lens groups of Example 4.
(Table 19)
Group number focal length
G1 163.4646
G2 -27.1555
G3 42.5800
G4 -58.9198
G5 30.1155
G6 -62.0549
G7 -52.1550

Table 20 shows the aspherical coefficients of the fourth embodiment.
(Table 20)
Aspheric coefficient (Aspheric coefficient not shown is 0.00000.)
Surface number K A4 A6 A8 A10 A12
6 0.0000 -6.33623E-07 5.25166E-09 -1.15628E-11 7.27254E-15 0.00000E+00
7 0.0000 2.74174E-07 1.99347E-09 2.62210E-11 -6.48205E-14 0.00000E+00
21 0.0000 2.01736E-06 1.91949E-09 -4.73234E-11 2.29474E-13 -2.05133E-16
24 0.0000 -7.39076E-06 -2.71133E-10 9.34250E-11 -4.95710E-13 2.17971E-15
25 0.0000 1.02751E-05 -7.03604E-09 4.20959E-11 -1.66847E-14 8.26127E-16
31 0.0000 -5.59575E-06 3.76510E-08 -5.94358E-10 3.17506E-12 0.00000E+00
32 0.0000 -8.92299E-06 4.32413E-08 -6.83984E-10 4.61131E-12 -1.71298E-15

(Fifth embodiment)
The fifth embodiment of the zoom lens according to the present invention, as shown in FIG. 17, includes, 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 positive refractive power. Third lens group G3 having power, negative fourth lens group G4, fifth lens group G5 having positive refractive power, sixth lens group G3 having negative refractive power, seventh lens group having negative refractive power G7, an eighth lens group G8 having a positive refractive power. A cover glass CG is arranged on the object plane side of the image plane IP.

In zooming from the wide-angle end to the telephoto end, the first lens group G1 moves to the object side, the second lens group G2 first moves to the image side and then to the object side, and the third lens group G3 moves to the object side. The fourth lens group G4 moves to the object side, the fifth lens group G5 moves to the object side, the sixth lens group G6 moves to the object side, and the seventh lens group G7 moves to the object side. , The eighth lens group G8 is fixed.

In zooming, the third lens group G3, the fifth lens group G5, and the seventh lens group G7 move on the same trajectory.
In focusing from an object at infinity to a near object, the sixth lens group G6 moves to the image side.

The aperture stop S is arranged adjacent to the object side of the third lens group G3.

The first lens group G1 is composed of, in order from the object side, a negative meniscus lens L1 having a convex surface facing the object side, a cemented lens with a biconvex lens L2, and a positive meniscus lens L3 having a convex surface facing the object side.
The second lens group G2 includes, in order from the object side, a negative meniscus lens L4 having a convex surface directed toward the object side, a biconcave lens L5, a biconvex lens L6, and a negative meniscus lens L7 having a convex surface directed toward the image side. Composed. The negative meniscus lens L4 is a glass mold type aspherical lens having an aspherical surface on the object side.
The third lens group G3 includes, in order from the object side, a positive meniscus lens L8 having a convex surface directed toward the object side, a positive meniscus lens L9 having a convex surface directed toward the object side, a negative meniscus lens L10 having a convex surface directed toward the object side, and a biconvex lens. It is composed of a cemented lens with L11.
The fourth lens group G4 is composed of a biconcave lens L12. The biconcave lens L12 is a composite resin type aspherical lens in which a composite resin film molded in an aspherical shape is attached to the object side surface.
The fifth lens group G5 is composed of, in order from the object side, a biconvex lens L13, and a cemented lens of a negative meniscus lens L14 having a convex surface facing the object side and a biconvex lens L15. The biconvex lens L13 is a glass mold type aspherical lens whose both surfaces are aspherical.
The sixth lens group G6 is composed of a negative meniscus lens L16 having a convex surface directed toward the object side. The negative meniscus lens L16 is a glass mold type aspherical lens whose both surfaces are aspherical.
The seventh lens group G7 is composed of, in order from the object side, a biconvex lens L17, a negative meniscus lens L18 having a convex surface facing the object side, and a negative meniscus lens L19 having a convex surface facing the image side.
The eighth lens group G8 is composed of a positive meniscus lens L20 having a convex surface directed toward the image side.

When the zoom lens vibrates due to camera shake or the like, at least one of the lenses forming the zoom lens is set as an image stabilization group, and the image stabilization is performed by decentering the image stabilization group. It is preferable to carry out. In particular, by moving any of the biconcave lens L12, the negative meniscus lens L16, or the negative meniscus lens L18 in the direction perpendicular to the optical axis, the image position can be corrected and the image blur caused by the vibration can be corrected.

The optical data of the fifth example is shown below.
Table 21 shows a specification table of the fifth embodiment.
(Table 21)
Wide-angle end Mid-telephoto end
f 28.7987 75.0047 193.9457
FNo. 2.8953 4.4488 5.7491
ω 37.9376 15.3537 6.1284
Y 21.6330 21.6330 21.6330

Table 22 shows the lens data of the fifth example.
(Table 22)
Surface number rd nd νd
Object plane ∞ d( 0)
1 118.0033 1.2000 1.85478 24.80
2 69.4123 7.4792 1.49700 81.61
3 -670.7371 0.2000
4 57.7559 5.2351 1.59349 67.00
5 170.5 119 d( 5)
6 ASPH 133.8594 1.1000 1.87070 40.73
7 20.9595 6.3434
8 -55.1909 0.8000 1.87070 40.73
9 31.8430 5.9831 1.84666 23.78
10 -39.0257 0.9000 1.80420 46.50
11 -143.7393 d(11)
12 S ∞ 1.2000
13 39.5525 2.4086 1.85478 24.80
14 121.6866 0.2000
15 47.5845 2.5435 1.72916 54.67
16 905.4101 0.2000
17 80.2627 0.9000 1.80809 22.76
18 34.7818 3.6239 1.49700 81.61
19 -69.5 512 d(19)
20 ASPH -25.0439 0.1502 1.51460 49.96
21 -28.8307 0.8000 1.85150 40.78
22 57.0750 d(22)
23 ASPH 23.1801 5.6114 1.69350 53.18
24 ASPH -51.2066 0.2000
25 32.4379 0.8000 1.91082 35.25
26 15.0371 6.2642 1.49700 81.61
27 -39.7892 d(27)
28 ASPH 125.0287 0.9000 1.59201 67.02
29 ASPH 19.7491 d(29)
30 41.7158 5.9160 1.67300 38.26
31 -37.8422 0.2000
32 98.4652 0.9000 1.77250 49.62
33 33.5680 6.2950
34 -20.1071 1.0000 1.88300 40.80
35 -115.7044 d(35)
36 -123.4320 3.0857 1.89190 37.13
37 -57.9987 d(37)
38 ∞ 2.5000 1.51680 64.20
39 ∞ 1.0000
Image plane ∞

Table 23 shows the lens intervals in the fifth example.
(Table 23)
Variable interval
Wide-angle mid-telephoto Wide-angle mid-telephoto
d(0) ∞ ∞ ∞ 163.0000 335.8143 613.0001
d(5) 0.8000 25.7813 49.5223 0.8000 25.7813 49.5223
d(11) 24.8039 11.5415 1.9078 24.8039 11.5415 1.9078
d(19) 1.9556 3.5631 6.3917 1.9556 3.5631 6.3917
d(22) 5.5363 3.9283 1.1000 5.5363 3.9283 1.1000
d(27) 1.3007 1.9879 1.3037 2.5777 4.2704 7.7360
d(29) 11.4698 10.7826 11.4668 10.1927 8.5002 5.0345
d(35) 0.8000 16.2673 24.9737 0.8000 16.2673 24.9737
d(37) 14.3945 14.3945 14.3945 14.3945 14.3945 14.3945

Table 24 shows the focal lengths of the lens groups according to the fifth example.
(Table 24)
Group number focal length
G1 103.3163
G2 -22.0310
G3 27.7736
G4 -21.0906
G5 19.2607
G6 -39.7433
G7 -103.9497
G8 120.0000

Table 25 shows the aspherical surface coefficients of the fifth embodiment.
(Table 25)
Aspheric coefficient (Aspheric coefficient not shown is 0.00000.)
Surface number K A4 A6 A8 A10 A12
6 0.0000 4.68825E-07 -8.27835E-10 -4.57198E-12 7.67646E-15 0.00000E+00
20 0.3504 3.73891E-05 -5.18836E-08 3.66348E-10 -1.59539E-12 5.19729E-15
23 0.5888 -2.02669E-05 -3.33921E-08 1.40579E-09 -1.30292E-11 4.62234E-14
24 0.0000 2.88003E-05 -1.09776E-07 2.13330E-09 -1.70982E-11 5.84447E-14
28 0.0000 -2.59801E-05 2.68797E-07 -1.40070E-09 -2.94779E-12 3.63924E-14
29 0.0000 -3.06852E-05 3.05237E-07 -2.43342E-09 4.13289E-12 1.23929E-14

(Imaging device)
As shown in FIG. 21, the image pickup apparatus 100 of the embodiment is configured by mounting the zoom lens 102 on the image pickup apparatus housing 104. The image pickup element IS of the image plane IP of the zoom lens 102 is arranged.

Table 26 shows the corresponding values of the conditional expressions of the examples.
(Table 26)
Value corresponding to conditional expression
Example 1 Example 2 Example 3 Example 4 Example 5
Conditional expression (1) f5/fw 0.663 0.647 1.084 1.045 0.669
Conditional expression (2) f1/fw 3.682 4.127 3.582 5.675 3.588
Conditional expression (3) f6it/ft -0.140 -0.173 -0.141 -0.062 -0.205
Conditional expression (4) M1/(Z×Y) 0.377 0.412 0.378 0.326 0.343
Conditional expression (5) oalw/fw 4.662 4.686 4.687 6.075 4.757
Conditional expression (6) f5/f3 0.673 0.622 1.150 0.707 0.693
Conditional expression (7) f35w/fw 0.914 0.915 0.987 1.136 0.886
Conditional expression (8) β6it/β6iw 1.568 1.370 1.589 1.852 1.487
Conditional expression (9) f6iw/fw -0.940 -1.122 -0.959 -0.909 -1.003
Example 1 Example 2 Example 3 Example 4 Example 5
f6it -27.082 -33.568 -27.390 -23.984 -39.804
M1 55.000 60.000 55.000 95.000 50.000
Z 6.735 6.734 6.734 13.464 6.735
Y 21.633 21.633 21.633 21.633 21.633
oalw 134.250 135.000 135.000 175.000 137.000
f35w 26.311 26.360 28.421 32.731 25.510
β6it 3.061 2.478 2.991 3.817 3.028
β6iw 1.952 1.808 1.883 2.061 2.036
f6iw -27.066 -32.324 -27.612 -26.175 -28.896

IP image forming surface IS image sensor S aperture stop CG cover glass G1 first lens group G2 second lens group G3 third lens group G4 fourth lens group G5 fifth lens group G6 sixth lens group G7 seventh lens group G8 8 lens group 100 imaging device 102 zoom lens 104 imaging device housing

Claims (15)

In order from the object side, the first lens group having a positive refractive power, the second lens group having a negative refractive power, the third lens group having a positive refractive power, the fourth lens group having a negative refractive power, and the positive lens group Is a zoom lens which has at least a fifth lens group having a refractive power of, a sixth lens group having a negative refractive power, and a seventh lens group having a negative refractive power, and in which a distance between adjacent lens groups changes during zooming. And a zoom lens that satisfies the following conditional expression.
0.3 ≤ f5 / fw ≤ 1.1 (1)
1.7 ≤ f1 / fw ≤ 8.0 (2)
However,
f1: focal length of the first lens group f5: focal length of the fifth lens group fw: focal length of the entire zoom lens system at the wide-angle end The zoom lens according to claim 1, wherein the first lens unit moves toward the object side during zooming from the wide-angle end to the telephoto end. The zoom lens according to claim 1, which satisfies the following conditional expression.
-0.24 ≤ f6it / ft ≤ -0.02 (3)
However,
f6it: Composite focal length from the sixth lens group to the most image side lens group at the telephoto end ft: Focal length of the entire zoom lens system at the telephoto end 4. The zoom lens according to claim 1, wherein the sixth lens group moves toward the image side when focusing from infinity to a short distance. The zoom lens according to any one of claims 1 to 4, which satisfies the following conditional expression.
0.2 ≤ M1 / (Z x Y) ≤ 0.6 (4)
However,
M1: amount of movement of the first lens unit during zooming Z: zoom ratio (=ft/fw)
Y: Maximum image height The zoom lens according to any one of claims 1 to 5, which satisfies the following conditional expression.
3.1 ≦ oalw / fw ≦ 7.0 (5)
However,
oalw: Distance from the lens surface closest to the object to the image plane at the wide-angle end The zoom lens according to any one of claims 1 to 6, which satisfies the following conditional expression.
0.3 ≤ f5 / f3 ≤ 1.2 (6)
However,
f3: focal length of the third lens group The zoom lens according to any one of claims 1 to 7, which satisfies the following conditional expression.
0.6 ≤ f35w / fw ≤ 1.5 (7)
However,
f35w: Composite focal length from the third lens group to the fifth lens group at the wide-angle end The zoom lens according to any one of claims 1 to 8, which satisfies the following conditional expression.
1.3 ≤ β6it / β6iw ≤ 2.2 (8)
However,
β6it: Composite lateral magnification from the sixth lens group at the telephoto end to the lens group closest to the image side β6iw: Combined lateral magnification from the sixth lens group at the wide angle end to the lens group closest to the image side The zoom lens according to any one of claims 1 to 9, which satisfies the following conditional expression.
-1.6 ≤ f6iw / fw ≤ -0.4 (9)
However,
f6iw: Composite focal length from the sixth lens group at the wide-angle end to the most image-side lens group The zoom lens according to any one of claims 1 to 10, wherein the third lens group and the fifth lens group move along the same movement locus during zooming. The zoom lens according to any one of claims 1 to 11, wherein the fifth lens group and the seventh lens group move along the same movement locus during zooming. 13. The third lens group, the fifth lens group, and the seventh lens group move along the same movement locus during zooming, according to any one of claims 1 to 12. Zoom lens. The zoom lens according to any one of claims 1 to 13, wherein the zoom lens comprises seven lens groups. A zoom lens according to any one of claims 1 to 14, and an image sensor for converting an optical image formed by the zoom lens into an electric signal on an image plane side of the zoom lens. An imaging device characterized by.

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