JP2021043375A - Zoom lens and image capturing device - Google Patents

Abstract

To provide a compact zoom lens with superior optical performance, and an image capturing device.SOLUTION: To solve the above problem, a zoom lens of the present invention consists of a lens group G1 having positive refractive power, a lens group G2 having negative refractive power, a lens group Gp consisting of one or more lens groups and having positive refractive power as a whole, and a lens group Gn consisting of two or more lens groups and having negative refractive power, arranged in order from the object side, the lens group Gn having a lens group Gf with negative refractive power located on the most object side. The zoom lens is configured to zoom by changing distances between adjacent lens groups and satisfy given conditional expressions. An image capturing device of the present invention is equipped with such zoom lens and an image sensor.SELECTED DRAWING: Figure 1

Description

The present invention relates to a zoom lens and an image pickup device, and more particularly to a zoom lens and an image pickup device suitable for an image pickup device using a solid-state image pickup element (CCD, CMOS, etc.) such as a digital still camera and a digital video camera.

Conventionally, an image pickup device using a solid-state image sensor such as a digital still camera or a digital video camera has become widespread. With the progress of increasing the number of pixels of solid-state image pickup devices, further improvement in performance is required for the image pickup optical system used in the image pickup apparatus. Further, with the miniaturization of the image pickup apparatus, the miniaturization of the image pickup optical system is also required. In particular, a telephoto zoom lens capable of magnifying a distant subject at a desired angle of view is required to achieve high magnification, high performance, and miniaturization.

For example, Patent Document 1 proposes a telephoto zoom lens of a type in which the first lens group is moved toward an object when the magnification is changed from the wide-angle end to the telephoto end. In the zoom lens described in Patent Document 1, a lens group having a positive refractive power is arranged on the most object side, a lens group having a negative refractive power is arranged on the image side, and an aperture diaphragm is arranged on the image side. There is. Further, the image side of the aperture diaphragm has a plurality of positive refractive power lens groups and a plurality of negative refractive power lens groups. In the zoom lens, the total length of the lens is achieved while achieving high optical performance over the entire zoom range and the entire object distance by setting the refractive power of each lens group and the movement conditions of each lens group at the time of magnification change. It is said that it is possible to realize a small zoom lens with a short length.

Japanese Unexamined Patent Publication No. 2019-101286

Although the zoom lens described in Patent Document 1 has a short optical total length at the wide-angle end, the effective diameter of the lens group arranged on the image side of the aperture diaphragm is large, and the miniaturization of the zoom lens in the radial direction is not sufficient. There are challenges. Further, in the zoom lens, focusing is performed by moving a lens group arranged on the image side of the aperture diaphragm. In the zoom lens described in Patent Document 1, the effective diameter of the focus group is large and the weight reduction is not sufficient. Therefore, the mechanism for driving the focus group is also large, so that the entire lens unit is also large. There are challenges.

An object of the present invention is to provide a zoom lens and an imaging device that are compact and have high optical performance.

In order to solve the above problems, the zoom lens according to the present invention is composed of a lens group G1 having a positive refractive force, a lens group G2 having a negative refractive force, and one or more lens groups in order from the object side. It is composed of a lens group Gp having a positive refractive force as a whole and a lens group Gn having a negative refractive force as a whole composed of two or more lens groups, and the lens group Gn has the most negative refractive force on the object side. It is characterized in that it has a lens group Gf having a lens group, and changes the magnification by changing the interval of each lens group, and satisfies the following conditional expression.
0.25 <Ft / (Lw × FNOt) <0.50 ・ ・ ・ ・ ・ (1)
2.00 <(Lw-Fw) / (Ft × tan (ωt)) <5.50 ... (2)
0.80 <Lpw / | Fnt | <3.50 ・ ・ ・ ・ ・ (3)
However,
Ft: Focal length at the telephoto end of the zoom lens Lw: Optical total length at the wide-angle end of the zoom lens FNOt: F number at the telephoto end of the zoom lens Fw: Focal length at the wide-angle end of the zoom lens ωt: Of the zoom lens Half angle of view at the telephoto end Lpw: Length on the optical axis from the most object side surface to the most image side surface of the lens group Gp at the wide angle end Fnt: Focal length at the telephoto end of the lens group Gn

In order to solve the above problems, the image pickup apparatus according to the present invention is characterized by including the zoom lens and an image pickup element that converts an optical image formed by the zoom lens into an electrical signal.

According to the present invention, it is possible to provide a zoom lens and an imaging device that are compact and have high optical performance.

The cross-sectional view of the zoom lens of Example 1 of the present invention at the time of focusing at the wide-angle end infinity is shown. The aberrations at the wide-angle end ((a) in the figure) and the telephoto end ((b) in the figure) of the zoom lens of the first embodiment at the time of focusing at infinity are shown. The cross-sectional view of the zoom lens of Example 2 of the present invention at the time of focusing at the wide-angle end infinity is shown. The aberrations at the wide-angle end ((a) in the figure) and the telephoto end ((b) in the figure) of the zoom lens of the second embodiment at the time of focusing at infinity are shown. The cross-sectional view of the zoom lens of Example 3 of the present invention at the time of focusing at the wide-angle end infinity is shown. Aberrations at the wide-angle end ((a) in the figure) and the telephoto end ((b) in the figure) of the zoom lens of Example 3 when in focus at infinity are shown. The cross-sectional view of the zoom lens of Example 4 of the present invention at the time of focusing at the wide-angle end infinity is shown. The aberrations at the wide-angle end ((a) in the figure) and the telephoto end ((b) in the figure) of the zoom lens of the fourth embodiment at the time of focusing at infinity are shown.

Hereinafter, embodiments of the zoom lens and the imaging device according to the present invention will be described. However, the zoom lens and the imaging device described below are one aspect of the zoom lens and the imaging device according to the present invention, and the zoom lens and the imaging device according to the present invention are not limited to the following aspects.

The zoom lens of the present embodiment is composed of a lens group G1 having a positive refractive power, a lens group G2 having a negative refractive power, and one or more lens groups in order from the object side, and has positive refraction as a whole. It is composed of a lens group Gp having a force and a lens group Gn composed of two or more lens groups and having a negative refractive power as a whole.

In this way, by adopting a telephoto type power arrangement in which the lens group G1 arranged on the most object side has a converging action and the lens group placed on the object side has a diverging action, the zoom is concerned. It becomes easy to narrow the angle of view at the telephoto end while suppressing the increase in size of the lens. That is, since the zoom lens of the present embodiment adopts a power arrangement suitable for a telephoto zoom lens, it is suitable for a single-lens reflex camera, a mirrorless camera, etc. while achieving a narrow angle of view at the telephoto end. The back focus can be shortened and the whole can be made compact. However, in the present embodiment, a zoom lens in which the half angle of view (ω) at the wide-angle end is smaller than 25 degrees will be mainly described as an example.

The zoom lens of the present embodiment may be substantially composed of the lens group G1, the lens group G2, the lens group Gp, and the lens group Gn, and each of the lens group G1 on the object side. An optical element having no refractive power or having a very small refractive power between the lens groups or between the lens group Gn and the image plane (hereinafter, "an optical element having substantially no refractive power"). ") May be arranged. Examples of such an optical element include a protective filter for protecting the lens from dirt and scratches, and various filters such as an ND (Neutral Density) filter and a PL (Polarized Light) filter. Hereinafter, a configuration example of each lens group constituting the zoom lens will be described.

1-1 Configuration (1) Lens group G1
The lens group G1 is a lens group having a positive refractive power, and is a lens group arranged on the object side most among a plurality of lens groups substantially constituting the zoom lens. The configuration of the lens group G1 is not particularly limited, but it is preferable that the lens group G1 is composed of two or more lenses in order to suppress the occurrence of various aberrations, particularly spherical aberration, in the lens group G1. For example, it is more preferable that the lens group G1 is composed of at least two positive lenses and at least one negative lens because it is possible to suppress the occurrence of various aberrations, particularly spherical aberration and chromatic aberration.

(2) Lens group G2
The lens group G2 is a lens group having a negative refractive power, and is arranged adjacent to the lens group G1 on the image side of the lens group G1. Since the lens group G2 has a negative refractive power, it has at least one negative lens. The configuration of the lens group G2 is not particularly limited, but it is preferable that the lens group G2 is composed of three or more lenses in order to suppress various aberrations in the lens group G2, particularly the occurrence of curvature of field. For example, it is more preferable that the lens group G2 is composed of at least two negative lenses and at least one positive lens because various aberrations, particularly curvature of field and chromatic aberration can be suppressed.

(3) Lens group Gp
The lens group Gp is composed of one or more lens groups and has a positive refractive power as a whole. The lens group Gp is arranged adjacent to the image side of the lens group G2. As long as the lens group Gp has a positive refractive power as a whole, the number of lens groups constituting the lens group Gp and the sign of the refractive power of each lens group constituting the lens group Gp are not particularly limited. For example, the lens group Gp may be composed of one lens group having a positive refractive power, may be composed of a lens group having two or more positive refractive powers, or may be composed of one or more positive refractive powers. It may be composed of a lens group having a force and a lens group having one or more negative refractive powers. However, in order to reduce the size of the zoom lens, it is more preferable that the number of lens groups constituting the lens group Gp is 3 or less.

Since the lens group Gp has a positive refractive power as a whole, the incident luminous flux with respect to the lens group Gn arranged adjacent to the image side of the lens group Gp can be converged. Therefore, the diameter of the lens group Gn can be reduced.

Further, the lens group Gp preferably has at least one aspherical surface. By arranging at least one aspherical surface on the lens group Gp, it is possible to suppress the occurrence of various aberrations, particularly spherical aberration and coma aberration in the lens group Gp.

(4) Lens group Gn
The lens group Gn is composed of two or more lens groups and has a negative refractive power as a whole. The lens group Gn includes a lens group Gf having a negative refractive power on the most object side thereof, and one or more lens groups on the image side of the lens group Gf. That is, the lens group Gn is composed of a lens group Gf arranged adjacent to the lens group Gp on the image side of the lens group Gp and one or more lens groups arranged on the image side of the lens group Gf. ..

a) Lens group Gf
First, the lens group Gf will be described. As long as the lens group Gf has a negative refractive power, its specific configuration is not particularly limited. The zoom lens employs a refractive power arrangement of a lens group G1 having a positive refractive power, a lens group G2 having a negative refractive power, a lens group Gp having a positive refractive power, and a lens group Gn having a negative refractive power. doing. By arranging the lens group Gf having a negative refractive power on the most object side of the lens group Gn while adopting such a refractive power arrangement, the lens group is compared with other lens groups constituting the zoom lens. The lens diameter of Gf can be reduced. Therefore, by using the lens group Gf as the focus group, it is possible to reduce the size and weight of the focus group and to reduce the size and weight of the mechanism for driving the focus group. Therefore, it becomes easy to reduce the size and weight of the entire zoom lens unit. In this case, it is more preferable that the lens group Gf is composed of two or less lenses. Furthermore, if the lens group Gf is composed of one positive lens and one negative lens, the focus group can be made smaller and lighter, and various aberrations that occur when focusing from infinity to a nearby object, particularly It is more preferable because chromatic aberration can be suppressed.

b) Other lens groups The number of lens groups arranged on the object side of the lens group Gf may be 1 or more. As long as the lens group Gf has a negative refractive power as a whole in a state where the lens group Gf and other lens groups are included, the number of lens groups other than the lens group Gf constituting the lens group Gn, the sign of the refractive power, etc. Is not particularly limited.

The lens group Gn is preferably composed of five or more lenses as a whole. For example, when the lens group Gf is composed of two lenses, it is preferable that the other lens group is composed of three or more lenses. By configuring the lens group Gn with five or more lenses as a whole, it becomes easy to suppress the occurrence of various aberrations, particularly curvature of field and chromatic aberration in the lens group Gn. In particular, it is preferable that the lens group Gn is composed of at least three negative lenses and at least two positive lenses. With this configuration, it is possible to better suppress the occurrence of various aberrations, particularly curvature of field and chromatic aberration.

Further, the lens group Gn preferably has at least one aspherical surface. By arranging at least one aspherical surface on the lens group Gn, it becomes easy to suppress the occurrence of various aberrations, particularly curvature of field, in the lens group Gn. In particular, it is preferable that the lens arranged on the image side of the lens group Gn has an aspherical surface, and it is more preferable that both sides of the lens have an aspherical surface.

(5) Aperture diaphragm The arrangement of the aperture diaphragm in the zoom lens is not particularly limited. However, the aperture diaphragm referred to here means an aperture diaphragm that defines the luminous flux diameter of the zoom lens, that is, an aperture diaphragm that defines the F number of the zoom lens.

However, in the zoom lens, it is preferable to arrange the aperture diaphragm within the lens group Gp. For example, if the lens group Gp is composed of the object side partial group Gpf, the aperture diaphragm, and the image side partial group Gpr in order from the object side, the diameter of the aperture diaphragm can be reduced, and the opening and closing operation of the aperture diaphragm can be performed accordingly. The aperture unit for control can be miniaturized. By arranging the aperture diaphragm in the lens group Gp in this way, the diameter of each lens group constituting the lens group Gn arranged on the image side of the lens group Gp can be reduced. From these facts, it becomes easier to reduce the size and weight of the entire zoom lens unit. When the lens group Gp is composed of two or more lens groups, it is located between any two lens groups constituting the lens group Gp or within any one lens group constituting the lens group Gp. It is preferable to arrange an opening aperture.

1-2 Operation (1) Operation at the time of magnification change In the zoom lens, the magnification is changed by changing the air spacing of the lens groups adjacent to each other. Here, at the time of scaling, at least the air spacing of the lens groups adjacent to each other may change, and all the lens groups constituting the zoom lens may be moved in the optical axis direction, or a part of the lens groups may be moved in the optical axis direction. The lens group may be fixed in the optical axis direction, and other lens groups may be moved in the optical axis direction, and the presence / absence and the direction of movement of the individual lens groups are not particularly limited.

For example, when scaling from the wide-angle end to the telephoto end, the air spacing between the lens groups is increased so as to increase the distance between the lens group G1 and the lens group G2 and decrease the distance between the lens group G2 and the lens group Gp. It is preferable to change. By changing the air spacing in this way, it is possible to obtain a zoom lens having a short optical overall length as compared with the focal length at the telephoto end while achieving a high magnification ratio.

At this time, it is preferable to move the lens group G1 with respect to the image plane at the time of magnification change because a high magnification ratio can be obtained while shortening the optical total length at the wide-angle end. In particular, it is preferable to move the lens group G1 toward the object when the magnification is changed from the wide-angle end to the telephoto end in order to shorten the optical overall length at the wide-angle end.

Further, it is preferable to move the lens group G2 with respect to the image plane at the time of magnification change because a high magnification ratio can be obtained while shortening the optical total length at the wide-angle end.

In the zoom lens, when the lens group Gp is composed of two or more lens groups, the air spacing between the lens groups constituting the lens group Gp also changes at the time of magnification change. Further, it is assumed that the air spacing between the lens groups constituting the lens group Gn also changes at the time of magnification change.

(2) Operation at Focus In the zoom lens, it is preferable that the lens group Gf is configured to be movable on the optical axis when focusing from infinity to a nearby object, and the lens group Gf is set as the focus group. The direction of movement of the lens group Gf during focusing is not particularly limited, but for example, the lens group Gf can be moved toward the image side when focusing from infinity to a nearby object. ..

Further, in the zoom lens, a lens group other than the lens group Gf or a part of the other lens group is set as a focus group, and the lens group Gf and the other focus group are set as the focus group when focusing on a close object from infinity, respectively. It may be moved on the optical axis in different orbits. That is, the floating method may be adopted.

(3) Operation at the time of vibration isolation The zoom lens may be provided with a vibration isolation lens group capable of shifting the image by moving the zoom lens in a direction substantially orthogonal to the optical axis. The arrangement of the anti-vibration lens group is not particularly limited, and may be all or a part of each lens group constituting the zoom lens, and the zoom lens may have a plurality of anti-vibration lens groups. It may be configured to have a lens group.

1-3 Conditional expression It is preferable that the zoom lens adopts the above-described configuration and satisfies one or more conditional expressions described below.

1-3-1. Conditional expression (1)
0.25 <Ft / (Lw × FNOt) <0.50 ・ ・ ・ ・ ・ (1)
However,
Ft: Focal length at the telephoto end of the zoom lens Lw: Optical total length at the wide-angle end of the zoom lens FNOt: F number at the telephoto end of the zoom lens

The conditional expression (1) is an expression that defines the focal length at the telephoto end of the zoom lens and the optical total length at the wide-angle end of the zoom lens. By satisfying the conditional expression (1), it is possible to realize a zoom lens having high optical performance while suppressing an increase in the size of the zoom lens.

On the other hand, when the numerical value of the conditional expression (1) becomes less than the lower limit value, the total optical length at the wide-angle end of the zoom lens becomes too long with respect to the focal length at the telephoto end of the zoom lens, and the zoom lens It becomes difficult to reduce the size of the lens. On the other hand, when the numerical value of the conditional expression (1) becomes equal to or larger than the upper limit value, the optical total length at the wide-angle end of the zoom lens becomes too short with respect to the focal length at the telephoto end of the zoom lens. In this case, it is difficult to correct the aberration because the refractive power of each lens group is large. On the other hand, in order to realize a zoom lens having high optical performance, it is necessary to increase the number of lenses for aberration correction, and it becomes difficult to reduce the size of the zoom lens. That is, it becomes difficult to achieve both miniaturization and high performance of the zoom lens.

In order to obtain these effects, the lower limit of the conditional expression (1) is more preferably 0.27, more preferably 0.28, and even more preferably 0.29. It is more preferably 30. The upper limit of the conditional expression (1) is more preferably 0.45, more preferably 0.42, more preferably 0.40, and even more preferably 0.38. .. When adopting these preferable lower limit values or upper limit values, the inequality sign (<) may be replaced with the equal sign inequality sign (≦) in the conditional expression (1). The same applies to other conditional expressions.

1-3-2. Conditional expression (2)
2.00 <(Lw-Fw) / (Ft × tan (ωt)) <5.50 ... (2)
However,
Fw: Focal length at the wide-angle end of the zoom lens ωt: Half angle of view at the telephoto end of the zoom lens

The conditional expression (2) is an expression that defines the total optical length at the wide-angle end of the zoom lens and the maximum image height at the telephoto end of the zoom lens. By satisfying the conditional expression (2), it becomes easy to narrow the angle of view at the telephoto end while suppressing the enlargement of the zoom lens.

On the other hand, when the numerical value of the conditional expression (2) exceeds the upper limit value, the total optical length at the wide-angle end of the zoom lens becomes too long with respect to the maximum image height of the zoom lens, and the size of the zoom lens becomes small. It becomes difficult to achieve the conversion. On the other hand, when the numerical value of the conditional expression (2) is equal to or less than the lower limit value, the optical total length at the wide-angle end of the zoom lens becomes too short with respect to the maximum image height of the zoom lens. In this case, it is difficult to correct the aberration because the refractive power of each lens group is large. On the other hand, in order to realize a zoom lens having high optical performance, it is necessary to increase the number of lenses for aberration correction, and it becomes difficult to reduce the size of the zoom lens. That is, it becomes difficult to achieve both miniaturization and high performance of the zoom lens.

In order to obtain these effects, the lower limit of the conditional expression (2) is more preferably 2.20, more preferably 2.40, and even more preferably 2.60. It is more preferably 80. The upper limit of the conditional expression (2) is more preferably 5.30, more preferably 5.10, more preferably 4.90, and even more preferably 4.70. ..

1-3-3. Conditional expression (3)
0.80 <Lpw / | Fnt | <3.50 ・ ・ ・ ・ ・ (3)
However,
Lpw: Length on the optical axis from the outermost object side surface to the most image side surface of the lens group Gp at the wide-angle end Fnt: Focal length at the telephoto end of the lens group Gn

The conditional expression (3) is an expression that defines the length of the lens group Gp at the wide-angle end on the optical axis and the focal length of the lens group Gn at the telephoto end. By satisfying the conditional equation (3), the total optical length of the zoom lens at the wide-angle end can be reduced while suppressing an increase in the size of the lens group arranged on the image side of the lens group Gp, particularly the lens group Gf. Can be shortened.

On the other hand, when the numerical value of the conditional expression (3) is equal to or less than the lower limit value, the lens group Gp is composed of a small number of lenses, so that various aberrations generated in the lens group Gp, particularly spherical aberration and chromatic aberration, are suppressed. Becomes difficult. On the other hand, if the value of the conditional expression (3) exceeds the upper limit value, the length of the entire lens group arranged on the image side from the lens group Gp on the optical axis becomes too long, and the zoom lens at the wide-angle end becomes too long. It becomes difficult to shorten the total optical length.

In order to obtain these effects, the lower limit of the conditional expression (3) is more preferably 0.84, more preferably 0.87, more preferably 0.90, and 0. It is more preferably 92. The upper limit of the conditional expression (3) is more preferably 3.20, more preferably 2.80, more preferably 2.40, and even more preferably 2.00. ..

1-3-4. Conditional expression (4)
0.40 << | Fnt | / Fpt <1.60 ... (4)
However,
Fpt: Focal length at the telephoto end of the lens group Gp

The conditional expression (4) is an expression that defines the focal length of the lens group Gp at the telephoto end and the focal length of the lens group Gn at the telephoto end. By satisfying the conditional expression (4), it becomes easy to suppress an increase in the size of the lens group Gn. Therefore, it becomes easier to realize a zoom lens having high optical performance while reducing the size of the zoom lens.

On the other hand, when the numerical value of the conditional expression (4) exceeds the upper limit value, the refractive power of the lens group Gp becomes too large, and it is difficult to suppress various aberrations generated in the lens group Gp, especially spherical aberration and coma. become. On the other hand, when the numerical value of the conditional expression (4) becomes less than the lower limit value, the refractive power of the lens group Gp becomes too small, so that the incident light beam diameter to the lens group Gn arranged on the object side of the lens group Gp is sufficiently small. This makes it difficult to suppress the increase in size of the lens group Gn.

In order to obtain these effects, the lower limit of the conditional expression (4) is more preferably 0.45, more preferably 0.50, and even more preferably 0.55. It is more preferably 60. The upper limit of the conditional expression (4) is more preferably 1.50, more preferably 1.40, more preferably 1.30, and even more preferably 1.25. ..

1-3-5. Conditional expression (5)
1.00 <Fw / | F2 | <4.50 ・ ・ ・ ・ ・ (5)
However,
F2: Focal length of lens group G2

The conditional expression (5) is an expression that defines the focal length of the zoom lens and the focal length of the lens group G2 at the wide-angle end. By satisfying the conditional expression (5), it is possible to realize a zoom lens having high optical performance while shortening the total optical length at the wide-angle end of the zoom lens.

On the other hand, when the numerical value of the conditional expression (5) becomes less than the lower limit value, the refractive power of the lens group G2 becomes too small. Therefore, in order to obtain a predetermined magnification ratio, the scaling from the wide-angle end to the telephoto end is performed. Sometimes it is necessary to increase the distance that the lens group G2 moves on the optical axis. Therefore, for example, since it is necessary to secure an air gap between the lens group G2 and the lens group G3 according to the amount of movement, it becomes difficult to shorten the optical overall length at the wide-angle end of the zoom lens. On the other hand, when the numerical value of the conditional expression (5) becomes equal to or more than the upper limit value, the refractive power of the lens group G2 becomes too large, and it becomes difficult to suppress various errors generated in the lens group G2, particularly curvature of field and distortion. It becomes difficult to realize a zoom lens with high optical performance.

In order to obtain these effects, the lower limit of the conditional expression (5) is more preferably 1.20, more preferably 1.30, and even more preferably 1.40. It is more preferably 50. The upper limit of the conditional expression (5) is more preferably 4.00, more preferably 3.75, more preferably 3.50, and even more preferably 3.25. ..

1-3-6. Conditional expression (6)
0.15 << F2 | / Lw <0.40 ・ ・ ・ ・ ・ (6)
However,
F2: Focal length of lens group G2

The conditional expression (6) is an expression that defines the focal length of the lens group G2 and the optical total length at the wide-angle end of the zoom lens. By satisfying the conditional expression (6), it is possible to realize a zoom lens having high optical performance while widening the angle of view at the wide-angle end of the zoom lens and realizing a high magnification ratio.

On the other hand, when the numerical value of the conditional expression (6) becomes less than the lower limit value, the refractive power of the lens group G2 becomes too large, so that various errors generated in the lens group G2, particularly curvature of field and distortion, are suppressed. It becomes difficult, and it becomes difficult to realize a zoom lens having high optical performance. On the other hand, when the numerical value of the conditional expression (6) becomes equal to or larger than the upper limit value, the refractive power of the lens group G2 becomes too small, and it becomes difficult to widen the angle of view at the wide-angle end of the zoom lens. It becomes difficult to increase the ratio.

In order to obtain these effects, the lower limit of the conditional expression (6) is more preferably 0.16, more preferably 0.17, and even more preferably 0.18. It is more preferably 19. The upper limit of the conditional expression (6) is more preferably 0.36, more preferably 0.34, more preferably 0.32, and even more preferably 0.30. ..

1-3-7. Conditional expression (7)
0.20 <F1 / Ft <1.50 ・ ・ ・ ・ ・ (7)
However,
F1: Focal length of lens group G1

The conditional expression (7) is an expression that defines the focal length of the lens group G1 and the focal length at the telephoto end of the zoom lens. By satisfying the conditional expression (7), it becomes easy to narrow the angle of view at the telephoto end while suppressing the enlargement of the zoom lens. In addition, various aberrations can be corrected with a small number of lenses, and a compact zoom lens with high optical performance can be realized.

On the other hand, when the numerical value of the conditional expression (7) becomes less than the lower limit value, the refractive power of the lens group G1 becomes too large with respect to the focal length at the telephoto end of the zoom lens, and various aberrations in the lens group G1. Will increase, and it will be difficult to correct various aberrations in the lens group on the image side of the lens group G1. Therefore, in order to realize a zoom lens having high optical performance, it is necessary to increase the number of lenses for aberration correction, and it becomes difficult to reduce the size of the zoom lens. On the other hand, when the numerical value of the conditional expression (7) becomes equal to or more than the upper limit value, the refractive power of the lens group G1 becomes too small with respect to the focal length at the wide-angle end of the zoom lens. In this case, in order to obtain a predetermined magnification ratio, it is necessary to increase the distance from the lens group G1 to the lens group on the image side. Therefore, the total optical length of the zoom lens at the wide-angle end becomes too long, and it becomes difficult to reduce the size.

In order to obtain these effects, the lower limit of the conditional expression (7) is more preferably 0.24, more preferably 0.28, and even more preferably 0.32. It is more preferably 35. The upper limit of the conditional expression (7) is more preferably 1.30, more preferably 1.20, more preferably 1.10, and even more preferably 1.00. ..

1-3-8. Conditional expression (8)
1.00 <F1 / Fw <3.00 ・ ・ ・ ・ ・ (8)
The conditional expression (8) is an expression that defines the focal length of the lens group G1 and the focal length at the wide-angle end of the zoom lens. By satisfying the conditional expression (8), it becomes easy to widen the angle of view at the wide-angle end while suppressing the enlargement of the zoom lens. In addition, various aberrations can be corrected with a small number of lenses, and a compact zoom lens with high optical performance can be realized.

On the other hand, when the numerical value of the conditional expression (8) is equal to or less than the lower limit value, the refractive power of the lens group G1 becomes too large with respect to the focal length at the wide-angle end of the zoom lens. In this case, since the amount of various aberrations generated in the lens group G1 becomes large, it becomes difficult to sufficiently correct these various aberrations in the lens group on the image side from the lens group G1. Therefore, in order to realize a zoom lens having high optical performance, it is necessary to increase the number of lenses for aberration correction, and it becomes difficult to reduce the size of the zoom lens. On the other hand, when the numerical value of the conditional expression (8) exceeds the upper limit, the refractive power of the lens group G1 becomes too small with respect to the focal length at the wide-angle end of the zoom lens. In this case, since the incident light flux cannot be sufficiently converged by the lens group G1, it is necessary to increase the diameter of the lens group arranged on the image side of the lens group G1. Therefore, in this case as well, it becomes difficult to reduce the size of the zoom lens.

In order to obtain these effects, the lower limit of the conditional expression (8) is more preferably 1.10, more preferably 1.20, and even more preferably 1.30. It is more preferably 40. The upper limit of the conditional expression (8) is more preferably 2.80, more preferably 2.60, still more preferably 2.40, and even more preferably 2.30. ..

1-3-9. Conditional expression (9)
60 <ν2nmax <110 ・ ・ ・ ・ ・ (9)
However,
ν2nmax: Maximum value of Abbe number in the d line of the negative lens included in the lens group G2

The conditional expression (9) is an expression that defines the maximum value of the Abbe number in the d-line of the negative lens included in the lens group G2. By satisfying the conditional expression (9), it is possible to satisfactorily correct the fluctuation of chromatic aberration due to the scaling from the wide-angle end to the telephoto end.

On the other hand, when the numerical value of the conditional expression (9) is equal to or less than the lower limit value, the chromatic aberration at the telephoto end is overcorrected, while the chromatic aberration at the wide-angle end is insufficiently corrected. Further, when the numerical value of the conditional expression (9) becomes equal to or more than the upper limit, the chromatic aberration at the wide-angle end is overcorrected, while the chromatic aberration at the telephoto end is insufficiently corrected.

In order to obtain these effects, the lower limit of the conditional expression (9) is more preferably 65, more preferably 70, more preferably 74, and even more preferably 77. The upper limit of the conditional expression (9) is more preferably 100, more preferably 96, more preferably 92, and even more preferably 85.

1-3-10. Conditional expression (10)
0.50 <(β2t / β2w) / Z <1.20 ・ ・ ・ ・ ・ (10)
However,
Z = Ft / Fw
β2w: Lateral magnification of lens group G2 at wide-angle end infinity focus β2t: Lateral magnification of lens group G2 at telephoto end infinity focus

The conditional expression (10) is an expression that defines the contribution of the lens group G2 to the magnification change from the wide-angle end to the telephoto end of the zoom lens. By satisfying the conditional expression (10), it is possible to realize a zoom lens having high optical performance while shortening the total optical length at the wide-angle end of the zoom lens.

On the other hand, when the numerical value of the conditional expression (10) becomes equal to or less than the lower limit value, the contribution of the scaling by the lens group arranged on the image side of the lens group G2 is increased in order to obtain a predetermined scaling ratio. There is a need. Therefore, it is necessary to increase the amount of movement of the lens group arranged on the image side of the lens group G2 at the time of magnification change and increase the refractive power. For these reasons, it becomes difficult to shorten the total optical length and suppress the amount of various aberrations generated at the wide-angle end of the zoom lens. On the other hand, when the numerical value of the conditional expression (10) exceeds the upper limit, the contribution of the variable magnification by the lens group G2 becomes too large. In this case, since the refractive power of the lens group G2 becomes too large, it becomes difficult to suppress various aberrations generated in the lens group G2, particularly curvature of field and distortion.

In order to obtain these effects, the lower limit of the conditional expression (10) is more preferably 0.53, more preferably 0.56, and even more preferably 0.60. It is more preferably 63. The upper limit of the conditional expression (10) is more preferably 1.15, more preferably 1.12, more preferably 1.09, and even more preferably 1.06. ..

1-3-11. Conditional expression (11)
0.50 <Fpt / | Ff | <1.50 ・ ・ ・ ・ ・ (11)
However,
Fpt: Focal length at the telephoto end of the lens group Gp Ff: Focal length of the lens group Gf

The conditional expression (11) is an expression that defines the focal length of the lens group Gp and the focal length of the lens group Gf at the telephoto end. By satisfying the conditional expression (11), it is possible to realize a zoom lens having high optical performance while reducing the diameter of the lens group Gf.

On the other hand, when the numerical value of the conditional expression (11) becomes less than the lower limit value, the refractive power of the lens group Gp at the telephoto end becomes too large, so that various aberrations generated in the lens group Gp, particularly spherical aberration and coma, are affected. It becomes difficult to suppress. On the other hand, when the numerical value of the conditional expression (11) becomes equal to or larger than the upper limit value, the refractive power of the lens group Gp becomes too small, so that the incident light beam diameter to the lens group Gf arranged on the image side of the lens group Gp becomes large. It becomes difficult to reduce the diameter of the lens group Gf.

In order to obtain these effects, the lower limit of the conditional expression (11) is more preferably 0.60, more preferably 0.65, and even more preferably 0.70. It is more preferably 75. The upper limit of the conditional expression (11) is more preferably 1.30, more preferably 1.20, more preferably 1.10, and even more preferably 1.00. ..

1-3-12.
0.20 <R1f / Ft <100.00 ・ ・ ・ ・ ・ (12)
However,
R1f: Radius of curvature of the outermost object side surface of the lens group G1 The code for the radius of curvature of the lens surface is such that the center of the spherical surface on the optical axis of the lens surface is the apex of the lens surface (the intersection of the lens surface and the optical axis). The sign of the radius of curvature of the lens surface is positive when it is on the image side, and the sign is negative when it is on the object side.

The conditional expression (12) is an expression that defines the radius of curvature of the side surface of the outermost object of the lens group G1 and the focal length at the telephoto end of the zoom lens. Since the conditional expression (12) takes a positive value, it is shown that the most object side surface of the lens group G1 has a shape or a plane convex toward the object side. By satisfying the conditional equation (12), various aberrations, particularly distortion and curvature of field can be satisfactorily corrected.

On the other hand, when the numerical value of the conditional expression (12) becomes less than the lower limit value, the radius of curvature of the outermost object side surface of the lens group G1 becomes too small with respect to the focal length at the telephoto end of the zoom lens, and various aberrations occur. In particular, it becomes difficult to satisfactorily correct distortion and curvature of field.

On the other hand, when the numerical value of the conditional expression (12) becomes equal to or more than the upper limit value, the radius of curvature of the outermost object side surface of the lens group G1 becomes too large, and ghosts are likely to occur. This is due to the following reasons. The image plane of the zoom lens is flat. Further, a flat surface such as a cover glass may be arranged between the most image side surface of the zoom lens and the image plane. The reflected light reflected on these planes arranged on the image side of the zoom lens is incident on the side surface of the most object of the lens group G1. At this time, if the radius of curvature of the outermost object side surface of the lens group G1 becomes too large, the light rereflected on the outermost object side surface may be incident on the image plane. Further, a plane such as various filters may be arranged at the tip of the zoom lens on the object side. If the radius of curvature of the outermost object side surface of the lens group G1 becomes too large, the light incident on the zoom lens may be reflected on the outermost object side surface, and the light rereflected on a plane such as a filter may be incident on the image plane. Ghosts are created by these re-reflected lights. Further, when the numerical value of the conditional expression (12) becomes equal to or more than the upper limit value, the effective diameter of the side surface of the outermost object also becomes large, which is not preferable in order to reduce the size of the zoom lens.

In order to obtain these effects, the lower limit of the conditional expression (12) is more preferably 0.25, more preferably 0.30, more preferably 0.35, and 0.40. Is more preferable. The upper limit of the conditional expression (12) is more preferably 60.00, more preferably 40.00, more preferably 20.00, and even more preferably 10.00. ..

1-3-13. Conditional expression (13)
0.25 <(Rff + Rfr) / (Rff-Rfr) <2.50 ・ ・ ・ ・ ・ (13)
However,
Rff: Radius of curvature of the most object side surface of the lens group Gf Rfr: Radius of curvature of the most image side surface of the lens group Gf

The conditional expression (13) is an expression that defines the radius of curvature of the outermost object side surface of the lens group Gf and the radius of curvature of the most image side surface of the lens group Gf. By satisfying the conditional expression (13), various aberrations, particularly spherical aberrations, can be satisfactorily corrected, and fluctuations in various aberrations due to focusing from infinity to a nearby object can be satisfactorily corrected.

On the other hand, when the numerical value of the conditional expression (13) is equal to or less than the lower limit value or more than the upper limit value, the amount of various aberrations, especially spherical aberration, generated on the outermost object side surface or the most image side surface of the lens group Gn1 becomes too large. In particular, when focusing on a nearby object from infinity by moving the lens group Gn1 in the optical axis direction, it becomes difficult to satisfactorily correct fluctuations in various aberrations associated therewith.

In order to obtain these effects, the lower limit of the conditional expression (13) is more preferably 0.35, more preferably 0.40, more preferably 0.45, and 0.50. Is more preferable. The upper limit of the conditional expression (13) is more preferably 2.25, more preferably 2.00, more preferably 1.75, and even more preferably 1.50.

1-3-14. Conditional expression (14)
0.25 <D12t / Fw <1.20 ・ ・ ・ ・ ・ (14)
However,
D12t: Length on the optical axis from the most image side surface of the lens group G1 at the telephoto end to the most object side surface of the lens group G2.

The conditional expression (14) is an expression that defines the length on the optical axis from the most image side surface of the lens group G1 at the telephoto end to the most object side surface of the lens group G2 and the focal length of the zoom lens at the wide-angle end. By satisfying the conditional expression (14), it is possible to realize a zoom lens having high optical performance while suppressing an increase in the size of the zoom lens.

On the other hand, when the numerical value of the conditional expression (14) becomes less than the lower limit value, the amount of movement of the lens group G2 at the time of scaling from the wide-angle end to the telephoto end becomes too small, and the aberration fluctuation due to the scaling becomes too small. It becomes difficult to suppress. On the other hand, when the numerical value of the conditional expression (14) exceeds the upper limit, the amount of movement of the lens group G2 at the time of scaling from the wide-angle end to the telephoto end becomes too large, and the total optical length of the zoom lens becomes long. It becomes difficult to miniaturize the zoom lens.

In order to obtain these effects, the lower limit of the conditional expression (14) is more preferably 0.30, more preferably 0.34, and even more preferably 0.37. It is more preferably 40, and even more preferably 0.5. The upper limit of the conditional expression (14) is more preferably 1.10, more preferably 1.00, more preferably 0.95, and even more preferably 0.90. ..

2. Imaging Device Next, the imaging device according to the present invention will be described. The image pickup apparatus according to the present invention is characterized by including the zoom lens according to the present invention and an image pickup element that converts an optical image formed by the zoom lens into an electrical signal. The image sensor is preferably provided on the image side of the zoom lens.

Here, the image sensor or the like is not particularly limited, and a solid-state image sensor such as a CCD (Charge Coupled Device) sensor or a CMOS (Complementary Metal Oxide Semiconductor) sensor can also be used. The image pickup device according to the present invention is suitable for an image pickup device using these solid-state image pickup elements such as a digital camera and a video camera. Further, the image pickup device may be a lens-fixed image pickup device in which the lens is fixed to a housing, or may be an interchangeable lens type image pickup device such as a single-lens reflex camera or a mirrorless single-lens camera. Of course. In particular, the zoom lens according to the present invention can secure a back focus suitable for an interchangeable lens system. Therefore, it is suitable for an imaging device such as a single-lens reflex camera equipped with an optical viewfinder, a phase difference sensor, a reflex mirror for branching light to these, and the like.

Further, the image pickup apparatus includes an image processing unit that electrically processes the captured image data acquired by the image pickup element to change the shape of the captured image, and an image correction used for processing the captured image data in the image processing unit. It is more preferable to have an image correction data holding unit or the like that holds data, an image correction program, or the like. When the zoom lens is miniaturized, distortion (distortion) of the imaged image shape formed on the image plane tends to occur. At that time, the image correction data holding unit holds the distortion correction data for correcting the distortion of the captured image shape in advance, and the image processing unit uses the distortion correction data held in the image correction data holding unit. , It is preferable to correct the distortion of the captured image shape. According to such an imaging device, it is possible to further reduce the size of the zoom lens, obtain a beautiful captured image, and reduce the size of the entire imaging device.

Further, in the image pickup apparatus, the image correction data holding unit holds the Magnification chromatic aberration correction data in advance, and the image processing unit uses the Magnification chromatic aberration correction data held in the image correction data holding unit to perform the imaging. It is preferable to correct the magnification chromatic aberration of the image. By correcting the chromatic aberration of magnification by the image processing unit, the number of lenses constituting the optical system can be reduced. Therefore, according to such an imaging device, it is possible to further reduce the size of the zoom lens, obtain a clear captured image, and reduce the size of the entire imaging device.

Next, the present invention will be specifically described with reference to Examples. However, the present invention is not limited to the following examples.

(1) Optical Configuration of Zoom Lens FIG. 1 shows a cross-sectional view of a relens at infinity focusing at the wide-angle end of the zoom lens of the first embodiment. “IMG” shown in the figure is an imaging surface, and specifically represents an imaging surface of a solid-state image sensor such as a CCD sensor or a CMOS sensor, or a film surface of a silver halide film. Further, a parallel flat plate having no substantial refractive power such as a cover glass "CG" is provided on the object side of the image plane IMG. Since these points are the same in the cross-sectional views of each lens shown in other examples, the description thereof will be omitted below.

The zoom lens of the first embodiment includes a lens group G1 having a positive refractive power, a lens group G2 having a negative refractive power, and a lens group Gp having a positive refractive power as a whole, in order from the object side. It is composed of a lens group Gn having a negative refractive power. Here, the lens group Gp is composed of a lens group G3 having a positive refractive power and a lens group G4 having a positive refractive power in order from the object side, and the lens group Gn is negative in order from the object side. It is composed of a lens group Gf having a refractive power, a lens group G6 having a negative refractive power, and a lens group G7 having a positive refractive power.

Hereinafter, the configuration of each lens group will be described. The lens group G1 is composed of a bonded lens in which a meniscus-shaped negative lens L1 having a convex shape on the object side and a positive lens L2 having a biconvex shape are joined, and a positive lens L3 having a biconvex shape in this order from the object side.

The lens group G2 is a bonded lens in which a negative lens L4 having a concave shape, a negative lens L5 having a concave shape, and a positive lens L6 having a meniscus shape convex on the object side are joined in this order from the object side, and a negative lens having a double concave shape. It is composed of a lens L7.

The lens group G3 is composed of a biconvex positive lens L8. The object side surface of the positive lens L8 is an aspherical surface.

The lens group G4 includes a biconvex positive lens L9, a biconvex positive lens L10, and a biconcave negative lens L11 joined in order from the object side, and an object side planar negative lens L12. It is composed of a bonded lens in which a biconvex positive lens L13 is joined and a biconvex positive lens L14. An aperture diaphragm S is arranged in the lens group G4.

The lens group Gf is composed of a bonded lens in which a biconvex positive lens L15 and a biconcave negative lens L16 are joined in order from the object side.

The lens group G6 is composed of a meniscus-shaped negative lens L17 that is convex on the object side. The object side surface of the negative lens L17 is an aspherical surface.

The lens group G7 is composed of a biconvex positive lens L18 and a meniscus-shaped negative lens L19 concave on the object side in order from the object side. Both sides of the negative lens L19 are aspherical.

In the zoom lens of Example 1, when the magnification is changed from the wide-angle end to the telescopic end, the lens group G1 moves to the object side, the lens group G2 moves to the image side, and the lens group G3 moves to the object side with respect to the image plane. The lens group G4 is fixed in a concave orbit, the lens group Gf is moved to the object side in a concave orbit, the lens group G6 is moved to the image side, and the lens group G7 is fixed.

In the zoom lens of the first embodiment, when focusing from infinity to a nearby object, the lens group Gf moves to the image side and the lens group G6 moves to the object side with respect to the image plane. The other lens groups are fixed to the image plane when in focus.

When the zoom lens vibrates due to camera shake or the like, at least one of the lenses constituting the zoom lens is set as an anti-vibration group, and the anti-vibration group is eccentric to correct image blur. It is preferable to do so.

(2) Numerical Example Next, a numerical example to which a specific numerical value of the zoom lens is applied will be described. Table 1 shows the surface data of the zoom lens of Example 1. In the table, "plane number" is the order of the lens surfaces counted from the object side, "r" is the radius of curvature, "d" is the lens thickness or lens spacing on the optical axis, and "Nd" is the refractive index on the d line. “Νd” indicates the Abbe number on the d line, and “φ” indicates the effective diameter of the lens. Further, "ASP" displayed on the right side of the surface number indicates that the lens surface is an aspherical surface, and "S" indicates an aperture diaphragm. Further, "D ○○ (where the surface number is entered in ○○)" in the lens spacing column is a variable spacing in which the spacing on the optical axis of the lens surface changes when the magnification is changed or when the lens is focused. Means that.

Table 2 shows the specifications of the zoom lens of the first embodiment. 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 image height, and "TL" is the total optical length.

Table 3 shows the variable intervals of the zoom lens of Example 1 at the time of infinity focusing. In the table, "f" indicates the focal length of the entire system, "shooting distance" indicates the distance from the image plane to the object, and "INF" indicates ∞ (infinity).

Table 4 shows the variable intervals of the zoom lens of Example 1 when the close object is in focus. The "shooting distance" in the table indicates the distance from the image plane to the object.

Table 5 shows the aspherical coefficient of each aspherical surface of the zoom lens of Example 1.
“K, A4, A6, A8, A10, A12, A14” in the table are coefficients when each aspherical shape is defined by the following formula.

X (Y) = CY ² / [1 + {1- (1 + Κ) ・ C ² Y ² } ^1/2 ] + A4 ・ Y ⁴ + A6 ・ Y ⁶ + A8 ・ Y ⁸ + A10 ・ Y ¹⁰ + A12 / Y ¹² + A14 / Y ¹⁴
However, in the table, " ^En " indicates "x10-n". Further, in the above equation, "X" is the amount of displacement from the reference plane in the optical axis direction, "C" is the curvature at the surface apex, "Y" is the height from the optical axis in the direction perpendicular to the optical axis, and " “Κ” is the conic coefficient, and “An” is the nth-order aspherical coefficient.

The unit of length in each of the above tables is "mm", and the unit of angle of view is "°". Further, the radius of curvature "0.0000" means that the surface is a flat surface. Since the matters related to the above-mentioned tables are the same in each table shown in other examples, the description thereof will be omitted below.

[Table 1]
Surface number rd Nd νd φ
1 200.0000 1.500 1.80610 33.27 60.500
2 107.6500 5.900 1.43700 95.10 59.951
3-2760.0000 0.200 59.874
4 88.8800 7.000 1.49700 81.61 59.416
5 -5000.0000 D5 58.899
6 -192.1000 1.000 1.69680 55.46 34.600
7 110.4200 2.734 33.647
8-114.0000 1.000 1.49700 81.61 33.585
9 80.7400 3.000 1.92286 20.88 33.791
10 502.6000 1.939 33.723
11 -99.5000 1.000 1.69680 55.46 33.718
12 185.0000 D12 34.124
13 ASP 80.6553 0.250 1.51460 49.96 35.600
14 100.0000 4.900 1.83481 42.72 35.609
15 -100.0000 D15 35.556
16 74.0500 4.400 1.59282 68.62 34.246
17 -176.2000 0.200 33.749
18 92.0000 4.200 1.49700 81.61 32.190
19 -92.0000 1.000 1.85451 25.16 31.423
20 148.3000 2.272 30.320
21 S 0.0000 2.074 29.223
22 0.0000 1.000 1.90366 31.31 28.621
23 29.2400 7.500 1.49700 81.61 27.541
24 -315.0000 0.201 27.441
25 38.5500 5.600 1.60342 38.03 27.200
26 -70.5000 D26 26.983
27 198.0000 1.800 1.92286 20.88 23.008
28 -198.0000 0.800 1.77250 49.62 22.484
29 25.6100 D29 20.800
30 ASP -463.4111 0.150 1.51460 49.96 25.938
31 310.3200 1.000 1.85451 25.16 25.982
32 67.2000 D32 26.257
33 48.4500 6.000 1.91082 35.25 27.973
34 -48.4500 4.762 28.000
35 ASP -20.8842 2.000 1.85108 40.12 26.582
36 ASP -67.1148 29.793 27.875
37 0.0000 2.500 1.51633 64.14 42.044
38 0.0000 1.000 42.802

[Table 2]
f 72.102 101.789 174.600
Fno 2.910 2.910 2.910
ω 17.003 11.811 6.720
Y 21.633 21.633 21.633
TL 163.448 178.948 192.417

[Table 3]
f 72.102 101.789 174.600
Shooting distance INF INF INF
D5 3.247 30.546 62.724
D12 29.248 19.092 1.000
D15 3.329 1.686 1.069
D26 2.115 2.750 1.901
D29 15.413 15.587 15.512
D32 2.419 1.612 2.535

[Table 4]
Shooting distance 850.000 850.000 850.000
D26 3.817 5.978 10.907
D29 12.267 10.495 5.179
D32 3.863 3.475 3.862

[Table 5]
Surface number K A4 A6 A8 A10 A12 A14
13 0.00 -3.6774E-06 2.9970E-10 -9.1982E-13 5.5729E-15 -1.5995E-17 1.6461E-20
30 0.00 1.2249E-05 1.1169E-08 -1.3534E-10 8.8621E-13 -1.9489E-15 0.0000E + 00
35 0.00 5.3883E-05 -2.8626E-07 1.8129E-09 -6.4552E-12 9.8700E-15 1.5279E-18
36 0.00 4.6766E-05 -2.6564E-07 1.4488E-09 -5.0290E-12 8.2960E-15 -2.8195E-18

Further, FIG. 2 shows an aberration diagram of the zoom lens of the first embodiment at infinity focusing. (A) is an aberration diagram at the wide-angle end of the zoom lens, and (b) is an aberration diagram at the telephoto end of the zoom lens. In (a) and (b), spherical aberration [mm], astigmatism [mm], distortion [%], and chromatic aberration of magnification [mm] are shown in order from the left side.

In the spherical aberration diagram, the vertical axis represents the F number (indicated by Fno in the figure), the solid line represents the d line (indicated by d in the figure), the short dashed line represents the C line (indicated by C in the figure), and the long dashed line. Represents the characteristics of the g-line (indicated by g in the figure).

In the astigmatism diagram, the vertical axis represents the image height (indicated by Y in the figure), the solid line represents the characteristics of the sagittal plane (indicated by ΔS in the figure), and the broken line represents the characteristics of the meridional plane (indicated by ΔM in the figure). Represent each.

In the distortion diagram, the vertical axis represents the image height (indicated by Y in the figure).
In the chromatic aberration of magnification diagram, the vertical axis represents the image height (indicated by Y in the figure), the short dashed line represents the chromatic aberration of magnification of the C line in the d-line reference (indicated by C in the figure), and the long dashed line represents g in the d-line reference. The characteristics of the chromatic aberration of magnification of the line (indicated by g in the figure) are shown respectively.

Since the matters related to these aberration diagrams are the same in the aberration diagrams shown in other examples, the description thereof will be omitted below.

(1) Optical Configuration of Zoom Lens FIG. 3 shows a cross-sectional view of the zoom lens of the second embodiment.
The zoom lens has a lens group G1 having a positive refractive power, a lens group G2 having a negative refractive power, a lens group Gp having a positive refractive power, and a negative refractive power as a whole, in order from the object side. It is composed of a lens group Gn having a lens group. Here, the lens group Gp is composed of one lens group, and the lens group Gn is composed of a lens group Gf having a negative refractive power and a lens group G5 having a negative refractive power in order from the object side. Has been done.

Hereinafter, the configuration of each lens group will be described. The lens group G1 is composed of a bonded lens in which a meniscus-shaped negative lens L1 having a convex shape on the object side and a positive lens L2 having a biconvex shape are joined, and a positive lens L3 having a biconvex shape in this order from the object side.

In the lens group G2, a biconvex positive lens L4, a biconcave negative lens L5, a meniscus-shaped positive lens L6 concave on the object side, and a biconcave negative lens L7 are joined in this order from the object side. It is composed of a bonded lens and a biconcave negative lens L8.

In the lens group Gp, in order from the object side, a meniscus-shaped positive lens L9 that is convex on the object side, a biconvex positive lens L10, a biconvex positive lens L11, and a biconcave negative lens L12 are joined. A junction lens in which a junction lens, a meniscus-shaped negative lens L13 with a convex object side, and a positive lens L14 with a biconvex shape are joined, a meniscus-shaped positive lens L15 with a concave object side, and a negative lens L16 with a biconcave shape. It is composed of a bonded lens and a biconvex positive lens L17. The object side surface of the positive lens L17 is an aspherical surface. The aperture diaphragm S is arranged in the lens group Gp.

The lens group Gf is composed of a bonded lens in which a meniscus-shaped positive lens L18 having a concave shape on the object side and a negative lens L19 having a concave shape on the object side are joined in this order from the object side.

The lens group G5 includes a junction lens in which a meniscus-shaped negative lens L20 and a biconvex positive lens L21 are joined in this order from the object side, a biconvex positive lens L22, and a biconcave negative lens. It is composed of a bonded lens to which L23 is bonded and a negative lens L24 having a meniscus shape with a concave on the object side. Both sides of the negative lens L24 are aspherical.

In the zoom lens of the second embodiment, when the magnification is changed from the wide-angle end to the telescopic end, the lens group G1 moves toward the object side and the lens group G2 moves toward the object side in a concave orbit with respect to the image plane. Gp moves to the object side, the lens group Gf moves to the object side, and the lens group G5 moves to the object side.

In the zoom lens of the second embodiment, when focusing from infinity to a nearby object, the lens group Gf moves toward the image side with respect to the image plane, and the other lens groups are fixed.

When the zoom lens vibrates due to camera shake or the like, at least one of the lenses constituting the zoom lens is set as an anti-vibration group, and the anti-vibration group is eccentric to correct image blur. It is preferable to do so. In particular, the image position is corrected by moving the junction lens in which the meniscus-shaped positive lens L15 having a concave shape on the object side and the negative lens L16 having a biconcave shape are joined in the direction perpendicular to the optical axis, and the image blurring due to vibration is caused. Can be corrected.

(2) Numerical Example Next, a numerical example to which a specific numerical value of the zoom lens is applied will be described. Table 6 shows the surface data of the zoom lens of Example 2. Table 7 shows the specifications of the zoom lens of the second embodiment. Table 8 shows the variable intervals of the zoom lens of Example 2 at the time of infinity focusing. Table 9 shows the variable intervals of the zoom lens of Example 2 when the close object is in focus. Table 10 shows the aspherical coefficient of each aspherical surface of the zoom lens of Example 2. Further, FIG. 4 shows an aberration diagram of the zoom lens of the second embodiment at infinity focusing.

[Table 6]
Surface number rd Nd νd φ
1 378.8036 2.200 1.83481 42.72 77.000
2 119.7867 9.047 1.43700 95.10 76.336
3-558.5566 0.200 76.419
4 117.9999 8.819 1.49700 81.61 76.570
5 -763.9338 D5 76.255
6 86.8672 5.988 1.85478 24.80 41.500
7 -207.0552 0.200 40.399
8-1245.8911 1.200 1.49700 81.61 39.295
9 66.5815 3.850 36.733
10 -157.7890 2.489 1.85883 30.00 36.594
11 -80.9803 1.000 1.49700 81.61 36.235
12 64.6768 4.995 33.996
13 -58.3530 1.000 2.00100 29.13 33.923
14 292.5908 D14 34.449
15 58.4287 4.184 1.65844 50.88 37.000
16 523.3761 0.200 36.843
17 53.7893 5.733 1.49700 81.61 36.607
18 -156.9519 0.200 36.209
19 38.6025 6.708 1.49700 81.61 33.488
20 -95.4739 1.000 1.91082 35.25 32.486
21 93.9998 6.777 30.935
22 S 0.0000 3.144 28.191
23 43.1020 1.000 2.00100 29.13 25.823
24 18.7666 5.997 1.53996 59.46 24.015
25 -616.6240 2.476 23.659
26 -155.5428 3.500 1.85478 24.80 23.500
27 -32.4489 1.000 1.85150 40.78 22.618
28 69.9419 2.000 22.376
29 ASP 32.2767 0.200 1.51460 49.96 22.885
30 32.0496 4.300 1.64769 33.84 22.846
31 -215.6784 D31 22.500
32 -218.9023 3.668 1.61340 44.27 20.497
33 -22.0274 1.000 1.59282 68.62 20.152
34 34.9770 D34 19.000
35 131.5626 1.000 1.92286 20.88 24.000
36 39.1472 5.634 1.61340 44.27 24.188
37 -40.8889 0.348 24.598
38 40.3084 6.142 1.69895 30.05 24.510
39 -28.1726 1.000 1.76385 48.49 24.094
40 31.9275 10.333 22.796
41 ASP -30.5135 2.000 1.85108 40.12 23.868
42 ASP -73.9512 D42 25.400
43 0.0000 2.500 1.51680 64.20 42.101
44 0.0000 1.000 42.855

[Table 7]
f 145.551 291.002 484.914
Fno 4.620 5.200 6.540
ω 8.124 4.050 2.466
Y 21.633 21.633 21.633
TL 229.015 275.621 304.009

[Table 8]
f 145.551 291.002 484.914
Shooting distance INF INF INF
D5 23.357 79.865 91.873
D14 31.070 13.868 1.000
D31 1.495 1.500 1.637
D34 21.984 28.192 49.063
D42 28.080 29.167 37.406

[Table 9]
Shooting distance 1500.000 1500.000 1500.000
D31 4.467 12.130 22.001
D34 19.012 17.562 28.699

[Table 10]
Surface number K A4 A6 A8 A10 A12 A14
29 0.00 -5.2292E-06 2.7552E-09 -1.6078E-12 9.3086E-14 -2.6469E-16 0.0000E + 00
41 0.00 -2.4930E-05 2.2640E-07 -9.3082E-10 2.8176E-12 -3.2570E-15 0.0000E + 00
42 0.00 -2.5651E-05 2.0345E-07 -8.7317E-10 2.5744E-12 -3.2515E-15 0.0000E + 00

(1) Optical Configuration of Zoom Lens FIG. 5 shows a cross-sectional view of the zoom lens of the third embodiment.
The zoom lens has a lens group G1 having a positive refractive power, a lens group G2 having a negative refractive power, a lens group Gp having a positive refractive power, and a negative refractive power as a whole, in order from the object side. It is composed of a lens group Gn having a lens group. Here, the lens group Gp is composed of one lens group, and the lens group Gn is composed of a lens group Gf having a negative refractive power and a lens group G5 having a negative refractive power in order from the object side. Has been done.

Hereinafter, the configuration of each lens group will be described. The lens group G1 is composed of a junction lens in which a meniscus-shaped negative lens L1 convex on the object side, a biconvex positive lens L2 are joined, and a biconvex positive lens L3 in order from the object side.

The lens group G2 is composed of a biconvex positive lens L4, a biconcave negative lens L5, a biconcave negative lens L6, and a biconcave negative lens L7 in order from the object side.

In the lens group Gp, in order from the object side, a meniscus-shaped positive lens L8 that is convex on the object side, a biconvex positive lens L9, a biconvex positive lens L10, and a biconcave negative lens L11 are joined. A bonded lens, a negative lens L12 having a convex meniscus shape on the object side, and a positive lens L13 having a biconvex shape are joined, and a positive lens L14 having a concave meniscus shape on the object side and a negative lens L15 having a biconcave shape are joined. It is composed of a bonded lens and a biconvex positive lens L16. The object side surface of the positive lens L16 is an aspherical surface. The aperture diaphragm S is arranged in the lens group Gp.

The lens group Gf is composed of a bonded lens in which a meniscus-shaped positive lens L17 having a concave shape on the object side and a negative lens L18 having a concave shape on the object side are joined in this order from the object side.

The lens group G5 includes a junction lens in which a meniscus-shaped negative lens L19 and a biconvex positive lens L20 are joined in this order from the object side, and a biconvex positive lens L21 and a biconcave negative lens. It is composed of a bonded lens to which L22 is bonded and a negative lens L23 having a meniscus shape with a concave on the object side. The object side surface of the negative lens L24 is an aspherical surface.

In the zoom lens of Example 3, when the magnification is changed from the wide-angle end to the telescopic end, the lens group G1 moves toward the object side and the lens group G2 moves toward the object side in a concave orbit with respect to the image plane. Gp moves to the object side, the lens group Gf moves to the object side, and the lens group G5 moves to the object side.

In the zoom lens of the third embodiment, when focusing from infinity to a nearby object, the lens group Gf moves toward the image side with respect to the image plane, and the other lens groups are fixed.

When the zoom lens vibrates due to camera shake or the like, at least one of the lenses constituting the zoom lens is set as an anti-vibration group, and the anti-vibration group is eccentric to correct image blur. It is preferable to do so. In particular, the image position is corrected by moving the junction lens in which the meniscus-shaped positive lens L14 having a concave shape on the object side and the negative lens L15 having a concave shape on both sides are joined in the direction perpendicular to the optical axis, and the image blurring due to vibration is caused. Can be corrected.

(2) Numerical Example Next, a numerical example to which a specific numerical value of the zoom lens is applied will be described. Table 11 shows the surface data of the zoom lens of Example 3. Table 12 shows the specifications of the zoom lens of Example 3. Table 13 shows the variable intervals of the zoom lens of Example 3 at the time of infinity focusing. Table 14 shows the variable intervals of the zoom lens of Example 3 when the close object is in focus. Table 15 shows the aspherical coefficient of each aspherical surface of the zoom lens of Example 3. Further, FIG. 6 shows an aberration diagram of the zoom lens of the second embodiment at infinity focusing.

[Table 11]
Surface number rd Nd νd φ
1 252.9796 2.000 1.83481 42.72 72.000
2 101.1184 8.000 1.49700 81.61 71.197
3 -28452.1133 0.200 71.199
4 113.0187 8.413 1.43700 95.10 71.202
5 -547.1978 D5 70.901
6 67.3736 4.933 1.85478 24.80 38.500
7 -285.1443 0.960 37.689
8-4239.3734 1.200 1.49700 81.61 35.871
9 49.9262 4.846 33.178
10 -333.4232 1.000 1.49700 81.61 32.143
11 77.0639 3.674 31.019
12 -65.1518 1.000 2.00100 29.13 30.934
13 208.4448 D13 31.177
14 41.5463 4.784 1.60342 38.01 33.500
15 583.0256 0.200 33.210
16 55.2612 4.386 1.49700 81.61 32.540
17 -287.5881 0.200 31.961
18 39.1785 5.584 1.49700 81.61 29.613
19 -86.2582 1.000 1.95375 32.32 28.552
20 72.9439 6.772 27.038
21 S 0.0000 1.500 24.607
22 42.6601 1.000 2.00100 29.13 23.528
23 17.6997 6.896 1.53996 59.46 22.071
24 -234.3377 2.751 21.679
25 -115.6601 3.500 1.85478 24.80 21.500
26 -23.9263 1.000 1.83400 37.21 20.932
27 67.6789 2.500 20.678
28 ASP 31.8233 0.200 1.51460 49.96 21.237
29 31.5462 3.877 1.62004 36.30 21.207
30 -101.4175 D30 21.000
31 -291.9620 3.500 1.61340 44.27 18.758
32 -24.4108 1.000 1.59282 68.62 18.282
33 32.2489 D33 17.500
34 57.1496 1.000 1.92286 20.88 20.500
35 30.3367 4.285 1.61340 44.27 20.555
36 -54.7847 0.200 20.820
37 32.5351 4.423 1.69895 30.05 20.964
38 -45.3585 1.000 1.76385 48.49 20.591
39 20.8008 20.481 19.570
40 ASP -32.8737 0.200 1.51460 49.96 26.684
41 -35.4191 2.000 1.77250 49.62 26.668
42 -73.4135 D42 28.411
43 0.0000 2.500 1.51680 64.20 42.076
44 0.0000 1.000 42.831

[Table 12]
f 146.743 290.947 484.837
Fno 5.190 5.600 6.920
ω 8.063 4.049 2.499
Y 21.633 21.633 21.633
TL 209.014 252.251 284.006

[Table 13]
f 146.743 290.947 484.837
Shooting distance INF INF INF
D5 15.048 75.537 90.869
D13 28.982 9.477 1.000
D30 8.683 7.766 2.003
D33 14.817 17.316 29.389
D42 18.519 19.189 37.779

[Table 14]
Shooting distance 1500.000 1500.000 1500.000
D30 12.104 20.803 22.001
D33 11.396 4.279 9.390

[Table 15]
Surface number K A4 A6 A8 A10 A12 A14
28 0.00 -5.3161E-06 5.2358E-09 -1.2300E-11 2.3331E-13 -6.9119E-16 0.0000E + 00
40 0.00 1.2000E-05 4.4169E-09 8.7723E-11 -3.2876E-13 6.5768E-16 0.0000E + 00

(1) Optical Configuration of Zoom Lens FIG. 7 shows a lens cross-sectional view of the zoom lens of the fourth embodiment.
The zoom lens has a lens group G1 having a positive refractive power, a lens group G2 having a negative refractive power, a lens group Gp having a positive refractive power, and a negative refractive power as a whole, in order from the object side. It is composed of a lens group Gn having a lens group. Here, the lens group Gp is composed of one lens group, and the lens group Gn is composed of a lens group Gf having a negative refractive power and a lens group G5 having a negative refractive power in order from the object side. Has been done.

Hereinafter, the configuration of each lens group will be described. The lens group G1 is composed of a bonded lens in which a meniscus-shaped negative lens L1 having a convex shape on the object side and a positive lens L2 having a biconvex shape are joined, and a positive lens L3 having a biconvex shape in this order from the object side.

In the lens group G2, a biconvex positive lens L4, a biconcave negative lens L5, an object side concave meniscus-shaped positive lens L6, and a biconcave negative lens L7 are joined in this order from the object side. It is composed of a bonded lens and a biconcave negative lens L8.

The lens group Gp includes a biconvex positive lens L9, a biconvex positive lens L10, a biconvex positive lens L11, and a biconcave negative lens L12 joined in order from the object side. , A junction lens in which a negative lens L13 having a convex meniscus shape on the object side and a positive lens L14 having a biconvex shape are joined, and a junction lens in which a positive lens L15 having a meniscus shape on the object side and a negative lens L16 having a biconcave shape are joined. It is composed of a lens and a biconvex positive lens L17. The object side surface of the positive lens L17 is an aspherical surface. The aperture diaphragm S is arranged in the lens group Gp.

The lens group Gf is composed of a bonded lens in which a meniscus-shaped positive lens L18 having a concave shape on the object side and a negative lens L19 having a concave shape on the object side are joined in this order from the object side.

In the lens group G5, a junction lens in which a biconcave negative lens L20 and a biconvex positive lens L21 are joined, and a biconvex positive lens L22 and a biconcave negative lens L23 are joined in order from the object side. It is composed of a bonded lens and a negative lens L24 having a meniscus shape that is concave on the object side. Both sides of the negative lens L24 are aspherical.

In the zoom lens of Example 4, when the magnification is changed from the wide-angle end to the telescopic end, the lens group G1 moves toward the object side and the lens group G2 moves toward the object side in a concave orbit with respect to the image plane. Gp moves to the object side, the lens group Gf moves to the object side, and the lens group G5 moves to the object side.

In the zoom lens of the fourth embodiment, when focusing from infinity to a nearby object, the lens group Gf moves toward the image side with respect to the image plane, and the other lens groups are fixed.

When the zoom lens vibrates due to camera shake or the like, at least one of the lenses constituting the zoom lens is set as an anti-vibration group, and the anti-vibration group is eccentric to correct image blur. It is preferable to do so. In particular, the image position is corrected by moving the junction lens in which the meniscus-shaped positive lens L15 having a concave shape on the object side and the negative lens L16 having a biconcave shape are joined in the direction perpendicular to the optical axis, and the image blurring due to vibration is caused. Can be corrected.

(2) Numerical Example Next, a numerical example to which a specific numerical value of the zoom lens is applied will be described. Table 16 shows the surface data of the zoom lens of Example 4. Table 17 shows the specifications of the zoom lens of Example 4. Table 18 shows the variable intervals of the zoom lens of Example 4 at the time of infinity focusing. Table 19 shows the variable intervals of the zoom lens of Example 4 when the close object is in focus. Table 20 shows the aspherical coefficient of each aspherical surface of the zoom lens of Example 4. FIG. 8 shows an aberration diagram of the zoom lens of the fourth embodiment at infinity focusing.

[Table 16]
Surface number rd Nd νd φ
1 221.4199 1.500 1.83481 42.72 61.000
2 78.1646 8.164 1.49700 81.61 60.256
3 -698.0413 0.200 60.284
4 82.5433 8.349 1.43700 95.10 60.196
5 -366.6570 D5 59.851
6 75.6021 4.903 1.85478 24.80 34.500
7 -152.9987 0.318 33.366
8 -237.3180 1.000 1.49700 81.61 32.302
9 52.9544 3.283 29.866
10 -116.0958 2.086 1.85478 24.80 29.747
11 -70.6858 1.000 1.49700 81.61 29.418
12 50.3883 4.192 27.694
13 -46.8787 1.000 2.00100 29.13 27.645
14 609.8769 D14 28.182
15 39.0992 4.672 1.61772 49.81 30.000
16 -731.2021 0.200 29.730
17 40.6633 4.267 1.49700 81.61 28.974
18 -879.0342 0.200 28.439
19 30.4749 5.442 1.49700 81.61 26.531
20 -89.4878 1.000 1.95375 32.32 25.493
21 75.3913 2.479 24.217
22 S 0.0000 1.500 22.646
23 40.5266 1.000 2.00100 29.13 21.857
24 14.7523 5.312 1.58144 40.89 20.030
25 601.5656 3.340 19.689
26 -122.2241 3.200 1.92286 20.88 19.000
27 -23.5972 0.800 1.90366 31.31 18.501
28 66.0190 2.500 18.122
29 ASP 28.0468 0.200 1.51460 49.96 18.229
30 29.2497 3.341 1.61340 44.27 18.199
31 -103.4552 D31 18.000
32 -254.5123 3.200 1.61340 44.27 16.231
33 -17.8374 0.800 1.59282 68.62 15.841
34 26.8496 D34 15.000
35 -278.5827 1.000 1.92286 20.88 22.000
36 75.4326 4.828 1.61340 44.27 22.447
37 -28.0885 0.200 22.941
38 45.9079 5.752 1.69895 30.05 23.387
39 -25.8278 1.000 1.76385 48.49 23.178
40 42.7801 5.215 22.670
41 ASP -26.6533 2.000 1.85108 40.12 22.719
42 ASP -64.5490 D42 25.087
43 0.0000 2.500 1.51680 64.20 42.039
44 0.0000 1.000 42.801

[Table 17]
f 97.152 193.972 387.840
Fno 4.620 5.200 6.540
ω 12.214 6.062 3.119
Y 21.633 21.633 21.633
TL 174.017 205.594 234.013

[Table 18]
f 97.152 193.972 387.840
Shooting distance INF INF INF
D5 2.000 43.393 58.641
D14 28.752 14.708 1.000
D31 3.365 4.104 2.208
D34 14.635 15.578 33.021
D42 23.323 25.870 37.200

[Table 19]
Shooting distance 950.000 950.000 950.000
D31 5.899 13.358 25.592
D34 12.101 6.324 9.637

[Table 20]
Surface number K A4 A6 A8 A10 A12 A14
29 0.00 -1.1205E-05 1.1668E-08 -1.8828E-11 8.7101E-13 -3.9367E-15 0.0000E + 00
41 0.00 -1.0161E-04 4.9685E-07 -1.5158E-09 2.2903E-12 2.4369E-15 0.0000E + 00
42 0.00 -9.4193E-05 5.2508E-07 -2.1301E-09 5.8930E-12 -7.3197E-15 0.0000E + 00

Table 21 shows the values of the conditional expressions (1) to (14) for the zoom lens in each embodiment. Table 22 shows the values used in the calculations of the conditional expressions (1) to (14) for the zoom lens in each embodiment.

[Table 21]
Example 1 Example 2 Example 3 Example 4
Conditional expression (1) Ft / (Lw × FNOt) 0.365 0.322 0.334 0.339
Conditional expression (2) (Lw-Fw) / (Ft × tan (ωt)) 4.489 4.045 2.990 3.684
Conditional expression (3) Lpw / | Fnt | 0.952 1.619 1.626 1.376
Conditional expression (4) | Fnt | / Fpt 1.173 0.700 0.627 0.815
Conditional expression (5) Fw / | F2 | 1.622 3.047 2.855 2.690
Conditional expression (6) | F2 | / Lw 0.270 0.208 0.245 0.206
Conditional expression (7) F1 / Ft 0.891 0.454 0.446 0.389
Conditional expression (8) F1 / Fw 2.159 1.511 1.475 1.555
Conditional expression (9) ν2nmax 81.607 81.607 81.607 81.607
Conditional expression (10) (β2t / β2w) / Z 1.044 0.668 0.783 0.648
Conditional expression (11) Fpt / | Ff | 0.812 0.809 0.894 0.825
Conditional expression (12) R1f / Ft 1.145 0.781 0.522 0.571
Conditional expression (13) (Rff + Rfr) / (Rff-Rfr) 1.297 0.724 0.801 0.809
Conditional expression (14) D12t / Fw 0.870 0.631 0.619 0.604

[Table 22]
Example 1 Example 2 Example 3 Example 4
Fw 72.102 145.551 146.743 97.152
Ft 174.600 484.914 484.837 387.840
F1 155.650 219.963 216.459 151.042
F2 -44.444 -47.769 -51.390 -36.113
Fpt 33.080 42.696 45.276 35.174
Fnt -38.797 -29.904 -28.381 -28.673
Ff -40.747 -52.801 -50.670 -42.644
Lw 164.448 230.015 210.014 175.017
Lpw 36.926 48.418 46.150 39.453
FNOt 2.910 6.540 6.920 6.540
ωt 6.720 2.466 2.499 3.119
β2w -0.452 -0.384 -0.416 -0.391
β2t -1.142 -0.855 -1.077 -1.012
Z 2.422 3.332 3.304 3.992
R1f 200.000 378.804 252.980 221.420
Rff 198.000 -218.902 -291.962 -254.512
Rfr 25.610 34.977 32.249 26.850
D12t 62.724 91.873 90.869 58.641

According to the present invention, it is possible to provide a zoom lens and an imaging device that are compact and have high optical performance. In particular, it is possible to reduce the size and improve the performance of a telephoto zoom lens having a half angle of view smaller than 25 degrees at the wide-angle end.

G1 ・ ・ ・ Lens group G1
G2 ・ ・ ・ Lens group G2
G3 ・ ・ ・ Lens group G3
G4 ・ ・ ・ Lens group G4
G5 ・ ・ ・ Lens group G5
G6 ・ ・ ・ Lens group G6
G7 ・ ・ ・ Lens group G7
Gp ・ ・ ・ Lens group Gp
Gn ・ ・ ・ Lens group Gn
Gf ・ ・ ・ Lens group Gf
S ・ ・ ・ Aperture aperture

Claims (13)

From the object side,
Lens group G1 with positive refractive power and
Lens group G2 with negative refractive power and
A lens group Gp consisting of one or more lens groups and having a positive refractive power as a whole,
A lens group Gn consisting of two or more lens groups and having a negative refractive power as a whole,
Consists of
The lens group Gn has a lens group Gf having the most negative refractive power on the object side.
The magnification is changed by changing the distance between each lens group.
A zoom lens characterized by satisfying the following conditional expression.
0.25 <Ft / (Lw × FNOt) <0.50 ・ ・ ・ ・ ・ (1)
2.00 <(Lw-Fw) / (Ft × tan (ωt)) <5.50 ... (2)
0.80 <Lpw / | Fnt | <3.50 ・ ・ ・ ・ ・ (3)
However,
Ft: Focal length at the telephoto end of the zoom lens Lw: Optical total length at the wide-angle end of the zoom lens FNOt: F number at the telephoto end of the zoom lens Fw: Focal length at the wide-angle end of the zoom lens ωt: Of the zoom lens Half angle of view at the telephoto end Lpw: Length on the optical axis from the most object side surface to the most image side surface of the lens group Gp at the wide angle end Fnt: Focal length at the telephoto end of the lens group Gn The zoom lens according to claim 1, which satisfies the following conditional expression.
0.40 << | Fnt | / Fpt <1.60 ... (4)
However,
Fpt: Focal length at the telephoto end of the lens group Gp The zoom lens according to claim 1 or 2, which satisfies the following conditional expression.
1.00 <Fw / | F2 | <4.50 ・ ・ ・ ・ ・ (5)
However,
F2: Focal length of the lens group G2 The zoom lens according to any one of claims 1 to 3, which satisfies the following conditional expression.
0.15 << F2 | / Lw <0.40 ・ ・ ・ ・ ・ (6)
However,
F2: Focal length of the lens group G2 The zoom lens according to any one of claims 1 to 4, which satisfies the following conditional expression.
0.20 <F1 / Ft <1.50 ・ ・ ・ ・ ・ (7)
However,
F1: Focal length of the lens group G1 The zoom lens according to any one of claims 1 to 5, which satisfies the following conditional expression.
1.00 <F1 / Fw <3.00 ・ ・ ・ ・ ・ (8)
However,
F1: Focal length of the lens group G1 The zoom lens according to any one of claims 1 to 6, which satisfies the following conditional expression.
60 <ν2nmax <110 ・ ・ ・ ・ ・ (9)
However,
ν2nmax: Maximum value of Abbe number in the d line of the negative lens included in the lens group G2 The zoom lens according to any one of claims 1 to 7, which satisfies the following conditional expression.
0.50 <(β2t / β2w) / Z <1.20 ・ ・ ・ ・ ・ (10)
However,
Z = Ft / Fw
β2w: Lateral magnification of the lens group G2 at wide-angle end infinity focus β2t: Lateral magnification of the lens group G2 at telephoto end infinity focus The zoom lens according to any one of claims 1 to 8, which satisfies the following conditional expression.
0.50 <Fpt / | Ff | <1.50 ・ ・ ・ ・ ・ (11)
However,
Fpt: Focal length at the telephoto end of the lens group Gp Ff: Focal length of the lens group Gf The zoom lens according to any one of claims 1 to 9, which satisfies the following conditional expression.
0.20 <R1f / Ft <100.00 ・ ・ ・ ・ ・ (12)
However,
R1f: Radius of curvature of the outermost object side surface of the lens group G1 The zoom lens according to any one of claims 1 to 10, which satisfies the following conditional expression.
0.25 <(Rff + Rfr) / (Rff-Rfr) <2.50 ・ ・ ・ ・ ・ (13)
However,
Rff: Radius of curvature of the most object side surface of the lens group Gf Rfr: Radius of curvature of the most image side surface of the lens group Gf The zoom lens according to any one of claims 1 to 11, which satisfies the following conditional expression.
0.25 <D12t / Fw <1.20 ・ ・ ・ ・ ・ (14)
However,
D12t: Length on the optical axis from the most image side surface of the lens group G1 at the telephoto end to the most object side surface of the lens group G2. An image pickup apparatus comprising the zoom lens according to any one of claims 1 to 12 and an image pickup element that converts an optical image formed by the zoom lens into an electrical signal.

Images