CN110412755B - Zoom lens and imaging device - Google Patents

Zoom lens and imaging device Download PDF

Info

Publication number
CN110412755B
CN110412755B CN201811403960.7A CN201811403960A CN110412755B CN 110412755 B CN110412755 B CN 110412755B CN 201811403960 A CN201811403960 A CN 201811403960A CN 110412755 B CN110412755 B CN 110412755B
Authority
CN
China
Prior art keywords
lens group
lens
zoom
refractive power
object side
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN201811403960.7A
Other languages
Chinese (zh)
Other versions
CN110412755A (en
Inventor
山中久幸
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Tamron Co Ltd
Original Assignee
Tamron Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Tamron Co Ltd filed Critical Tamron Co Ltd
Priority to CN202211244499.1A priority Critical patent/CN115657281A/en
Publication of CN110412755A publication Critical patent/CN110412755A/en
Application granted granted Critical
Publication of CN110412755B publication Critical patent/CN110412755B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B15/00—Optical objectives with means for varying the magnification
    • G02B15/14—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B15/00—Optical objectives with means for varying the magnification
    • G02B15/14—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective
    • G02B15/16—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective with interdependent non-linearly related movements between one lens or lens group, and another lens or lens group

Abstract

The invention provides a zoom lens with abundant peripheral light quantity, high optical performance and high zoom ratio and an imaging device with the zoom lens. In order to solve the above problems, a zoom lens provided is characterized by comprising, in order from an object side: a positive first lens group (G1), a negative second lens group (G2), a positive third lens group (G3), a positive fourth lens group (G4), a negative fifth lens group (G5) and a sixth lens group are arranged so that the distance between adjacent lens groups on the optical axis varies during zooming and a predetermined conditional expression is satisfied. Further, an imaging device is provided with the zoom lens.

Description

Zoom lens and imaging device
Technical Field
The present invention relates to a zoom lens and an imaging device, and more particularly to a zoom lens and an imaging device suitable for an imaging device using a solid-state imaging element (CCD, CMOS, or the like) such as a digital still camera or a digital video camera.
Background
Conventionally, imaging devices using solid-state imaging elements, such as digital cameras and digital video cameras, have been widely used. Examples of such an imaging device include various video cameras such as a digital still camera, a digital video camera, a broadcasting video camera, a movie video camera, a surveillance video camera, and a vehicle-mounted video camera. With the high integration of the light receiving element constituting the solid-state imaging device, all imaging apparatuses have been made to have higher functions and smaller sizes, and further higher performance and smaller sizes have been demanded for the imaging optical system of the imaging apparatus.
As an imaging optical system, a zoom lens has been widely used. In addition to high performance and miniaturization, zoom lenses are required to have a wide angle of view and high zoom ratio. For example, patent document 1 discloses a zoom lens composed of five lens groups of positive-negative-positive. In addition, patent document 2 discloses a zoom lens composed of six lens groups of positive-negative-positive-negative-positive. Such a so-called positive-lead type zoom lens is easy to realize high magnification, and has high degrees of freedom in the amount of movement and the direction of movement when moving each lens group during magnification change. Therefore, it is easy to realize a desired zoom ratio and suppress variation in aberration, and it is easy to realize a zoom lens having high optical performance over the entire zoom range.
[ Prior art documents ]
[ patent document ]
Patent document 1: japanese patent laid-open No. Hei 8-179213
Patent document 2: japanese patent laid-open publication No. 2017-151240
Disclosure of Invention
However, the zoom lens disclosed in patent document 1 has a small combined refractive power from the first lens group to the fourth lens group, the composite focal length indicates a negative value. In this zoom lens, the half angle of view at the wide-angle end is 41 degrees, achieving a wide angle, but the height of peripheral rays passing through the fifth lens group in the wide-angle end is high. Therefore, due to the inner diameter limitation of the camera mounting portion and the lens mounting portion, a dark angle of the peripheral light beam is generated, and it is difficult to secure a rich peripheral light amount. In addition, since the diameter of the final lens group, that is, the fifth lens group becomes large, it is also difficult to downsize the zoom lens in the radial direction. Further, the zoom lens disclosed in patent document 1 has a zoom ratio of about 4, and in order to achieve high zoom ratio, it is necessary to increase the amount of movement of each lens group during zooming. In order to achieve good imaging performance, the number of constituent lenses used for aberration correction needs to be increased. Thus, if a high magnification is desired, the total optical length becomes long, and it becomes difficult to secure the amount of peripheral light.
The zoom lens disclosed in patent document 2 realizes a high zoom ratio of about 12 times. However, in this zoom lens, since the combined refractive power from the first lens group to the fifth lens group is weak, the height of the peripheral light flux passing through the final lens group, that is, the sixth lens group is high, and it is difficult to secure the peripheral light amount and to downsize the lens in the radial direction.
The invention provides a zoom lens which has abundant peripheral light quantity, high optical performance and high zoom ratio and is small, and an imaging device with the zoom lens.
In order to solve the above problem, a zoom lens according to the present invention includes, in order from an object side: the zoom lens includes 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 positive refractive power, a fifth lens group having negative refractive power, and a sixth lens group, and an interval on an optical axis of adjacent lens groups changes when zooming, and the zoom lens satisfies the following conditional expression.
0.10≤f34w/|f5|≤0.75……(1)
-0.5≤fw/f5iw≤0.2……(2)
Wherein the content of the first and second substances,
f34w: a combined focal length of the third lens group and the fourth lens group at a wide-angle end;
f5: a focal length of the fifth lens group;
fw: a focal length of the zoom lens at a wide-angle end;
f5iw: a combined focal length from the fifth lens group at the wide-angle end to a lens group disposed on the most image side of the zoom lens.
In order to solve the above problem, an imaging device according to the present invention includes the zoom lens according to the present invention and an imaging element that converts an optical image formed by the zoom lens into an electric signal on an image side of the zoom lens.
The invention has the following beneficial effects:
according to the present invention, a zoom lens having a large amount of peripheral light, high optical performance, and a high zoom ratio, and being small in size, and an image pickup apparatus including the zoom lens can be provided.
Drawings
Fig. 1 shows a lens cross-sectional view at infinity focusing at the wide-angle end of a zoom lens according to embodiment 1 of the present invention.
Fig. 2 is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram at the wide-angle end in infinity focusing in example 1.
Fig. 3 is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram in infinity focusing at the first intermediate focal length position in example 1.
Fig. 4 is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram in infinity focusing at the second intermediate focal length position in example 1.
Fig. 5 is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram in infinity focusing at the telephoto end in example 1.
Fig. 6 shows a lens cross-sectional view at infinity focusing at the wide-angle end of a zoom lens according to embodiment 2 of the present invention.
Fig. 7 is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram at the wide-angle end in infinity focusing in example 2.
Fig. 8 is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram in infinity focusing at the first intermediate focal length position in example 2.
Fig. 9 is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram in infinity focusing at the second intermediate focal length position in example 2.
Fig. 10 is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram in infinity focusing at the telephoto end in example 2.
Fig. 11 shows a lens cross-sectional view at infinity focusing at the wide-angle end of a zoom lens according to embodiment 3 of the present invention.
Fig. 12 is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram at the wide-angle end in infinity focusing in example 3.
Fig. 13 is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram in infinity focusing at the first intermediate focal length position in example 3.
Fig. 14 is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram in infinity focusing at the second intermediate focal length position in example 3.
Fig. 15 is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram in infinity focusing at the telephoto end in example 3.
Fig. 16 shows a lens cross-sectional view in infinity focusing at the wide-angle end of a zoom lens according to embodiment 4 of the present invention.
Fig. 17 is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram at the wide-angle end in infinity focusing in example 4.
Fig. 18 is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram in infinity focusing at the first intermediate focal length position in example 4.
Fig. 19 is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram in infinity focusing at the second intermediate focal length position in example 4.
Fig. 20 is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram in infinity focusing at the telephoto end in example 4.
Fig. 21 shows a lens cross-sectional view at infinity focusing at the wide-angle end of a zoom lens according to embodiment 5 of the present invention.
Fig. 22 is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram at the wide-angle end in infinity focusing in example 5.
Fig. 23 is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram in infinity focusing at the first intermediate focal length position in example 5.
Fig. 24 is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram in infinity focusing at the second intermediate focal length position in example 5.
Fig. 25 is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram in infinity focusing at the telephoto end in example 5.
Fig. 26 shows a lens cross-sectional view at infinity focusing at the wide-angle end of a zoom lens according to embodiment 6 of the present invention.
Fig. 27 is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram at the wide-angle end in infinity focusing in example 6.
Fig. 28 is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram in infinity focusing at the first intermediate focal length position in example 6.
Fig. 29 is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram in infinity focusing at the second intermediate focal length position in example 6.
Fig. 30 is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram in infinity focusing at the telephoto end in example 6.
Fig. 31 shows a lens cross-sectional view at infinity focusing at the wide-angle end of a zoom lens according to embodiment 7 of the present invention.
Fig. 32 is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram at the wide-angle end in infinity focusing in example 7.
Fig. 33 is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram in infinity focusing at the first intermediate focal length position in example 7.
Fig. 34 is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram in infinity focusing at the second intermediate focal length position in example 7.
Fig. 35 is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram in infinity focusing at the telephoto end in example 7.
Fig. 36 shows a lens cross-sectional view at infinity focusing at the wide-angle end of a zoom lens according to embodiment 8 of the present invention.
Fig. 37 is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram at the wide-angle end in infinity focusing in example 8.
Fig. 38 is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram in infinity focusing at the first intermediate focal length position in embodiment 8.
Fig. 39 is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram in infinity focusing at the second intermediate focal length position in example 8.
Fig. 40 is a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram in infinity focusing at the telephoto end in example 8.
Description of the symbols
G1 … first lens group
G2 … second lens group
G3 … third lens group
G4 … fourth lens group
G5 … fifth lens group
G5A … fifth A lens group
G5B … fifth B lens group
G6 … sixth lens group
G7 … seventh lens group
S … aperture diaphragm
IP … image plane
Detailed Description
Embodiments of the zoom lens and the imaging apparatus according to the present invention will be described below. However, the zoom lens and the imaging device described below are one embodiment 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 embodiment.
1. Zoom lens
1-1. Constitution
First, an embodiment of the zoom lens according to the present invention will be described. The zoom lens of the present embodiment includes, in order from an object side: the zoom lens includes 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 positive refractive power, a fifth lens group having negative refractive power, and a sixth lens group, and intervals of adjacent lens groups on an optical axis vary upon zooming.
The zoom lens having the above configuration changes the interval between adjacent lens groups during zooming to thereby perform magnification change. Since the zoom lens includes at least six lens groups, the degree of freedom in the amount and direction of movement of each lens group during zooming is high. Therefore, by adopting the above configuration, it is easy to realize a high zoom ratio, and variation in aberrations in the entire zoom range is suppressed, so that a high-performance zoom lens can be obtained.
(1) First lens group
The specific lens configuration of the first lens group is not particularly limited as long as it has positive refractive power. For example, by adopting a configuration including two positive lenses and disposing a strong positive refractive power in the first lens group, a zoom lens that realizes a high zoom ratio and has a short optical total length at the telephoto end can be easily obtained. Further, it is preferable to adopt a configuration including at least one negative lens because spherical aberration can be easily corrected.
(2) Second lens group
The specific lens configuration of the second lens group is not particularly limited as long as it has negative refractive power. For example, by adopting a configuration including two or more negative lenses and disposing a strong negative refractive power in the second lens group, a zoom lens that realizes a high zoom ratio and has a short optical total length at the telephoto end can be easily obtained.
Preferably, at least one surface of the lens disposed closest to the image side in the second lens group is an aspherical surface. With such a configuration, the coma aberration on the wide angle side and the spherical aberration on the telephoto side can be corrected well in balance.
(3) Third lens group and fourth lens group
The third lens group and the fourth lens group are not particularly limited in specific lens configurations as long as they have positive refractive powers, respectively. However, it is preferable that, for example, at least any one of the third lens group and the fourth lens group has a positive lens on the most object side thereof. By disposing a positive lens on the most object side of at least one of the third lens group and the fourth lens group, it is easy to form lens groups disposed after the third lens group by lenses having a small diameter, and it is easy to downsize the zoom lens in the radial direction. At the same time, with this configuration, the exit pupil position can be easily brought close to the image plane side, and the peripheral light amount can be easily secured. In order to obtain this effect, it is preferable that positive lenses are disposed on the most object side of the two lens groups of the third lens group and the fourth lens group, respectively. The shape of the positive lens is not particularly limited, but from the viewpoint of obtaining the above-described effects, the positive lens more preferably has a convex surface on the object side. In addition, from the viewpoint of aberration correction, it is preferable that each lens group has at least one negative lens.
(4) Fifth lens group
The fifth lens group is not particularly limited as long as it has negative refractive power, and its specific lens configuration is, for example, preferably a fifth a lens group having negative refractive power and a fifth B lens group having positive refractive power or negative refractive power in order from the object side. In this case, the fifth a lens group can be used as an anti-shake group by being movable in a direction perpendicular to the optical axis. That is, when the zoom lens vibrates due to hand shake or the like, the image shake caused by the vibration can be corrected by moving the fifth a lens group in the direction perpendicular to the optical axis.
In the zoom lens, the third lens group and the fourth lens group each have positive refractive power, and therefore, the light fluxes converged in the third lens group and the fourth lens group enter the fifth a lens group. Therefore, the fifth a lens group can be constituted by a lens having a small diameter. Therefore, by using the fifth a lens group as the anti-shake group, it is easy to reduce the size and weight of the anti-shake group, and further, it is possible to reduce the size and weight of the drive mechanism for moving the anti-shake group in the direction perpendicular to the optical axis. This makes it possible to reduce the size and weight of the entire zoom lens unit.
Preferably, the fifth lens group has at least two positive lenses. By disposing at least two positive lenses in the fifth lens group having negative refractive power, the diameter of the lens group disposed on the image side of the fifth lens group can be reduced, and the amount of peripheral light can be more easily secured. From the viewpoint of obtaining this effect, it is preferable to dispose a positive lens on the image side of the fifth lens group, and it is more preferable to dispose a positive lens on the most image side of the fifth lens group. In the case where the fifth lens group is composed of the fifth a lens group and the fifth B lens group, it is preferable that, for example, the fifth a lens group and the fifth B lens group each have one positive lens, and from the viewpoint of obtaining the above-described effects, it is more preferable that the positive lens is disposed on the most image side of the fifth B lens group.
(5) Sixth lens group
The refractive power of the sixth lens group may be positive or negative, but preferably satisfies conditional expression (2) and conditional expression (5) described later. In the case where the sixth lens group has positive refractive power, negative distortion aberration generated in the second lens group can be eliminated by causing the sixth lens group to generate positive distortion aberration. From this viewpoint, it is more preferable that the sixth lens group has positive refractive power.
(6) Other lens group
The zoom lens may include another lens group such as a seventh lens group on the image side of the sixth lens group. That is, the zoom lens is not limited to the six-group structure of positive-negative-positive-negative-positive or positive-negative-positive-negative, and may be a lens group having one or more positive refractive powers or negative refractive powers on the image side of the sixth lens group.
However, when the number of lens groups constituting the zoom lens increases, it is difficult to achieve miniaturization and weight reduction of the zoom lens. In addition, when the number of lens groups constituting the zoom lens increases, a zoom mechanism for moving each lens group at the time of zooming becomes complicated, and the entire zoom lens unit is likely to be large-sized. From these viewpoints, the number of lens groups constituting the zoom lens is preferably 6 to 8, and preferably 6 or 7.
In addition, from the viewpoint of ensuring the peripheral light amount and correcting distortion aberration well, it is preferable that the lens group disposed on the image side of the sixth lens group has positive refractive power.
(7) Aperture diaphragm
In the zoom lens of the present embodiment, for example, an aperture stop is preferably disposed on the object side or image side of the third lens group, or within the third lens group, and particularly preferably disposed on the object side of the third lens group. When an aperture stop is disposed on the object side of the third lens group, the effective diameter of the first lens group at the wide-angle end is easily reduced, and the securing of the peripheral light quantity and the reduction of the filter diameter can be achieved at the same time.
1-2. Actions
(1) Zoom lens
In this zoom lens, as described above, the distance on the optical axis between the lens groups is changed to change the magnification. The interval on the optical axis between the lens groups may be changed during zooming, and all the lens groups may be moved in the optical axis direction, or a part of the lens groups may be fixed in the optical axis direction. The amount and direction of movement of each lens group are not particularly limited as long as a desired zoom ratio can be achieved, but are preferably set as follows, for example.
In zooming from the wide-angle end to the telephoto end, the first lens group, the third lens group, the fourth lens group, the fifth lens group, and the sixth lens group are preferably moved on the optical axis such that the lens groups are located on the object side at the telephoto end with respect to the position on the optical axis at the wide-angle end. By moving each lens group in this manner, miniaturization in the optical overall length direction at the wide-angle end is easily achieved. Further, by shortening the optical total length at the wide-angle end, it is easy to secure the peripheral light amount at the wide-angle end. Further, the movement locus of the first lens group, the third lens group, the fourth lens group, the fifth lens group, and the sixth lens group may be linear during zooming, or may be moved in the opposite direction after being moved to the image side or the object side. That is, the movement may be performed such that a convex locus is drawn on the image side or the object side. Further, the movement may be performed so as to draw a locus in an S-shape or an inverted S-shape. That is, the movement locus of each lens group (the first lens group, the third lens group, the fourth lens group, the fifth lens group, and the sixth lens group) is not particularly limited as long as the position of each lens group is on the object side at the telephoto end from the wide-angle end, and may be moved in any manner.
In order to achieve high zoom ratio of the zoom lens and suppress aberration variation in the entire zoom range, it is preferable to move the second lens group toward the image side to a predetermined intermediate focal length position and then move the second lens group from the predetermined intermediate focal length position toward the telephoto end to the object side upon zooming from the wide-angle end to the telephoto end. In this way, by moving the second lens group toward the image side from the wide-angle end to a prescribed intermediate focal length position, the composite zoom ratio from the third lens group to the final lens group can be enhanced in the zoom range on the wide-angle side. That is, in the zoom range on the wide angle side, it is possible to vary the magnification from the wide angle end to a prescribed intermediate focal length position while suppressing the moving amount of the lens groups after the third lens group. Further, by moving the second lens group from the predetermined intermediate focal length position toward the object side, it is possible to perform magnification variation while appropriately maintaining the magnification variation action of the second lens group. Therefore, it is difficult to generate an excessive magnification-varying load on each lens group, and it is possible to suppress aberration variation and realize high magnification variation.
Further, in zooming, the second lens group may be moved to the object side from the predetermined intermediate focal length position toward the telephoto end, and then moved to the image side again. That is, upon zooming from the wide-angle end to the telephoto end, the second lens group may be moved from the wide-angle end to the first intermediate focal length position toward the image side, moved from the first intermediate focal length position to the second intermediate focal length position toward the object side, and moved from the second intermediate focal length position toward the telephoto end again toward the image side. By moving the second lens group between the wide-angle end and the telephoto end in such an S shape, the total optical length of the zoom lens at the telephoto end can be suppressed, a high magnification ratio can be easily achieved, and the zoom lens can be miniaturized.
It is preferable that the following relationship is satisfied when a focal length of the zoom lens at the wide-angle end is fw, a focal length of the zoom lens at the telephoto end is ft, a focal length at the first intermediate focal length position is fm1, and a focal length at the second intermediate focal length position is fm 2.
fw＜fm1≤(fw×ft) 1/2
(fw×ft) 1/2 ＜fm2＜ft
In addition, in zooming from the wide-angle end to the telephoto end, the third lens group and the fourth lens group are preferably moved so that an interval between the third lens group and the fourth lens group on the optical axis is narrowed. At the wide-angle end, by enlarging the interval on the optical axis between the third lens group and the fourth lens group, divergent light emitted from the second lens group can be more effectively converged by the third lens group and the fourth lens group having positive refractive power, and therefore the effective diameters of the lens groups after the third lens group can be suppressed to be small, and the peripheral light amount can be easily secured.
Further, in zooming from the wide-angle end to the telephoto end, it is preferable that the lens groups are moved such that an interval on the optical axis between the first lens group and the second lens group becomes large, an interval on the optical axis between the second lens group and the third lens group becomes small, an interval on the optical axis between the fourth lens group and the fifth lens group becomes large, and an interval on the optical axis between the fifth lens group and the sixth lens group becomes small. By moving each lens group in this manner during zooming, it is difficult to cause a burden on the variable magnification action of each group, and high magnification and high performance can be achieved at the same time.
Further, in zooming from the wide-angle end to the telephoto end, the fourth lens group and the sixth lens group are preferably moved along the same locus. By moving the fourth lens group and the sixth lens group along the same trajectory, the fourth lens group and the sixth lens group can be configured as an integral structure. In a zoom lens, generally, a lens barrel is configured to have a double or multiple nested structure, and the position of each lens group is changed by rotating an inner cylinder or an outer cylinder in a state where a pin is engaged with a cam groove provided on a side surface of the inner cylinder or the outer cylinder. By integrating the fourth lens group and the sixth lens group, the cam structure can be simplified, and the lens barrel can be easily downsized. Further, by integrating the fourth lens group and the sixth lens group, relative decentering of the fourth lens group and the sixth lens group that may occur during zooming can be suppressed to be small, and thus deterioration of optical performance due to manufacturing errors can be suppressed. Further, moving along the same trajectory means: the interval on the optical axis between the fourth lens group and the sixth lens group does not change upon zooming, and is the same interval at any zooming position.
(2) Focusing
In the zoom lens of the present embodiment, it is preferable that the second lens group is moved on the optical axis when focusing from an infinity object to a close object. By setting the second lens group in which strong negative refractive power is arranged as the focus group, the amount of movement of the second lens group at the time of focusing can be reduced, and miniaturization of the total optical length can be easily achieved.
1-3. Conditional formula
The zoom lens preferably has the above-described configuration and satisfies at least one or more of the conditional expressions described below.
1-3-1. Conditional expression (1)
0.10≤f34w/|f5|≤0.75……(1)
Wherein the content of the first and second substances,
f34w: a composite focal length from the third lens group to the fourth lens group at the wide-angle end,
f5: focal length of the fifth lens group.
Conditional expression (1) is a conditional expression for specifying a ratio of a combined focal length of the third lens group and the fourth lens group at the wide-angle end to a focal length of the fifth lens group. By satisfying the conditional expression (1), it is easy to secure the peripheral light amount also at the wide-angle end, and a zoom lens having high optical performance can be obtained.
On the other hand, when the numerical value of the conditional expression (1) is equal to or less than the lower limit, it is easy to secure the peripheral light amount at the wide-angle end, but it is difficult to correct each aberration generated in the third lens group to the fifth lens group, particularly, spherical aberration at the telephoto end, satisfactorily. In this case, the back focal length of the zoom lens at the wide-angle end becomes short. Therefore, when the zoom lens is applied to an interchangeable lens for a single inverter, it is difficult to secure an appropriate back focus. If the upper limit of conditional expression (1) is exceeded, the positive combined refractive power from the third lens group to the fifth lens group becomes weak, and therefore, it is difficult to bring the exit pupil position closer to the image plane side, and it is difficult to secure the peripheral light amount.
From the viewpoint of obtaining the above-described effects, the upper limit value of the conditional expression (1) is preferably 0.70, more preferably 0.65, and still more preferably 0.60. The lower limit of conditional expression (1) is preferably 0.15, and more preferably 0.20.
1-3-2. Conditional expression (2)
-0.5≤fw/f5iw≤0.2……(2)
Wherein the content of the first and second substances,
fw: a focal length of the zoom lens at a wide-angle end,
f5iw: a combined focal length from the fifth lens group at the wide-angle end to a lens group disposed on the most image side of the zoom lens.
The conditional expression (2) is a conditional expression for specifying a ratio of a focal length of the zoom lens at the wide-angle end to a combined focal length from the fifth lens group at the wide-angle end to the most image side lens group. By satisfying the conditional expression (2), the zoom lens can be downsized in the overall length direction and can be corrected to have a good field curvature even at the wide-angle end.
On the other hand, when the numerical value of conditional expression (2) is equal to or less than the lower limit value, the zoom lens has a strong tendency to be telephoto. That is, the telescopic ratio becomes too small. In this case, since the amount of movement of each lens group during zooming can be suppressed, it is preferable to achieve downsizing in the overall length direction. However, since a large overcorrected field curvature occurs at the wide-angle end, a large number of lenses are required for aberration correction. When the numerical value of conditional expression (2) is equal to or greater than the upper limit value, the length Jiao Qingxiang decreases, and therefore the amount of movement of each lens group during zooming increases, making it difficult to achieve miniaturization in the overall length direction. In addition, since a large under-corrected field curvature occurs at the wide-angle end, a large number of lenses are required for aberration correction.
From the viewpoint of obtaining the above-described effects, the upper limit value of the conditional expression (2) is preferably 0.1, and more preferably 0.0. The lower limit of conditional formula (2) is preferably-0.40, more preferably-0.35, and still more preferably-0.30.
1-3-3. Conditional expression (3)
2.5≤f1/fw≤9.0……(3)
Wherein the content of the first and second substances,
f1: the focal length of the first lens group,
fw: a focal length of the zoom lens at a wide-angle end,
the conditional expression (3) is a conditional expression for specifying a ratio of a focal length of the first lens group to a focal length of the zoom lens at the wide-angle end. By satisfying the conditional expression (3), the zoom lens can be miniaturized and can have a wide angle of view (for example, a half angle of view of 40 degrees or more).
On the other hand, when the numerical value of conditional expression (3) is equal to or less than the lower limit value, the amount of movement of the first lens group during zooming can be reduced due to the high refractive power of the first lens group, which is advantageous for achieving downsizing of the zoom lens in the overall length direction. However, it is difficult to achieve a prescribed angle of view in the wide-angle end. In the case where it is necessary to enhance the negative refractive power of the second lens group to achieve a prescribed angle of view at the wide-angle end, correction of curvature of field becomes difficult. On the other hand, when the numerical value of conditional expression (3) is equal to or greater than the upper limit value, the refractive power of the first lens group is weak, and therefore, the moving amount of the first lens group upon zooming for achieving a high magnification ratio becomes large. Further, since the aperture diameter of the stop and the lens groups subsequent to the third lens group are also increased in diameter, it is difficult to reduce the size of the zoom lens.
From the viewpoint of obtaining the above-described effects, the upper limit value of conditional expression (3) is preferably 8.0, more preferably 7.0, and still more preferably 6.0. The lower limit of conditional expression (3) is preferably 3.5, more preferably 4.0, and still more preferably 4.5.
1-3-4. Conditional expression (4)
4.0≤T3w/Y≤8.0……(4)
Wherein the content of the first and second substances,
t3w: a distance on an optical axis from a most object side surface of the third lens group at the wide-angle end to an image forming surface,
y: maximum image height at the wide-angle end.
By satisfying the conditional expression (4), it is possible to suppress aberration variation in the entire zoom range and to realize a wide angle and high magnification at the wide angle end of the zoom lens. On the other hand, when the numerical value of conditional expression (4) is equal to or less than the lower limit, the wide angle is easily achieved, but it is difficult to suppress aberration variation during zooming and to achieve high zoom ratio. On the other hand, when the value of conditional expression (4) is equal to or greater than the upper limit value, the total optical length of the zoom lens at the wide-angle end becomes long, and it is therefore difficult to secure the peripheral light amount.
From the viewpoint of obtaining the above-described effects, the upper limit value of conditional expression (4) is preferably 7.0, more preferably 6.5, and still more preferably 6.0. The lower limit of conditional expression (4) is preferably 4.3, and more preferably 4.5.
1-3-5 conditional expression (5)
-0.10≤f345w/f6iw≤0.70……(5)
Wherein the content of the first and second substances,
f345w: a composite focal length from the third lens group to the fifth lens group at the wide-angle end,
f6iw: a combined focal length from the sixth lens group at the wide-angle end to the lens group disposed closest to the image side of the zoom lens.
The conditional expression (5) is a conditional expression for specifying a ratio of a combined focal length from the third lens group to the fifth lens group at the wide-angle end to a combined focal length from the sixth lens group to a lens group disposed closest to the image side among the zoom lenses. By satisfying the conditional expression (5), the peripheral light amount can be easily secured even at the wide-angle end. Here, in general, in the case where a wide angle is achieved at the wide angle end of the zoom lens, it is difficult to correct distortion aberration. In order to correct distortion aberration at the wide-angle end satisfactorily, it is necessary to generate positive distortion aberration in lens groups disposed after the third lens group, thereby eliminating negative distortion aberration generated in the second lens group. In particular, in the zoom lens, the lens groups disposed in the sixth lens group and subsequent lens groups on the image side are most likely to generate positive distortion aberration compared with other lens groups. Therefore, by setting the range satisfying the conditional expression (5), the ratio of the combined refractive power from the third lens group to the fifth lens group to the combined refractive power of the lens groups subsequent to the sixth lens group becomes appropriate, and distortion aberration can be corrected favorably even at the wide-angle end, and a zoom lens having high optical performance over the entire zoom range can be obtained.
On the other hand, when the numerical value of the conditional expression (5) is equal to or less than the lower limit value, the amount of generation of positive distortion aberration in the lens groups subsequent to the third lens group becomes small, and it becomes difficult to correct distortion aberration of the zoom lens at the wide-angle end satisfactorily. On the other hand, when the numerical value of conditional expression (5) is equal to or greater than the upper limit value, the positive combined refractive power from the third lens group to the fifth lens group becomes weak, and it becomes difficult to bring the exit pupil position closer to the image plane side, and it becomes difficult to secure the peripheral light amount.
From the viewpoint of obtaining the above-described effects, the upper limit value of conditional expression (5) is preferably 0.65, more preferably 0.60, and still more preferably 0.55. The lower limit of conditional expression (5) is preferably 0.0, and more preferably 0.10.
1-3-6. Conditional expression (6)
0.04≤|f2|/ft≤0.21……(6)
Wherein the content of the first and second substances,
f2: the focal length of the second lens group,
ft: the focal length of the zoom lens at the telephoto end.
The conditional expression (6) is a conditional expression for specifying a ratio of the focal length of the second lens group to the focal length of the zoom lens at the telephoto end. Satisfying the conditional expression (6) can obtain good optical performance and ensure a predetermined zoom ratio.
On the other hand, if the value of conditional expression (6) is equal to or less than the lower limit, the negative refractive power of the second lens group becomes too strong to exceed an appropriate range, and it becomes difficult to correct distortion aberration and field curvature. On the other hand, when the numerical value of conditional expression (6) is equal to or greater than the upper limit value, it is difficult to achieve a predetermined magnification ratio. In order to obtain a predetermined zoom ratio, the refractive power of the first lens group needs to be reduced, and along with this, the moving amount of the first lens group during zooming increases, and it is therefore difficult to shorten the total length of the zoom lens.
From the viewpoint of obtaining the above-described effects, the upper limit value of conditional expression (6) is preferably 0.20, and more preferably 0.19. The lower limit of conditional expression (6) is preferably 0.06, and more preferably 0.07.
1-3-7. Conditional expression (7)
-6.0≤Cr2r/fw≤-0.9……(7)
Wherein the content of the first and second substances,
cr2r: the curvature radius of the surface of the second lens group closest to the image side,
fw: a focal length of the zoom lens at a wide-angle end,
the conditional expression (7) is a conditional expression for specifying a ratio of a radius of curvature of a most image-side surface of the second lens group to a focal length of the zoom lens at the wide-angle end. By satisfying the conditional expression (7), spherical aberration and coma aberration can be corrected in balance over the entire zoom range.
When the numerical value of conditional expression (7) is less than or equal to the lower limit value, it is difficult to correct coma aberration at the wide-angle side of the zoom range. When the numerical value of conditional expression (7) is equal to or greater than the upper limit value, it is difficult to correct spherical aberration on the telephoto side of the zoom range.
The upper limit of the conditional expression (7) is preferably-1.0, more preferably-1.1, and still more preferably-1.2. The lower limit of conditional formula (7) is preferably-5.5, more preferably-5.0.
1-3-8. Conditional expression (8)
1.45≤BFw/Y……(8)
Wherein the content of the first and second substances,
BFw: a back focal length of the zoom lens at a wide-angle end,
y: the maximum image height at the wide-angle end.
The conditional expression (8) is a conditional expression for specifying a ratio of a back focal length of the zoom lens at the wide-angle end to a maximum image height at the wide-angle end of the zoom lens. By satisfying the conditional expression (7), an appropriate back focus required for an interchangeable lens for a single inverter can be ensured. If the conditional expression (8) is not satisfied, it is difficult to apply the zoom lens to an interchangeable lens for a single-lens reflex camera. However, in the case where the zoom lens is used as an imaging optical system of various imaging apparatuses such as a micro-single camera which does not include a mirror box, it is preferable to reduce the size of the zoom lens in the overall length direction at the wide-angle end.
1-3-9. Conditional expression (9)
1.0≤(ft/fw)/Fnom≤5.0……(9)
Wherein, the first and the second end of the pipe are connected with each other,
ft: the focal length of the zoom lens at the telephoto end,
fw: a focal length of the zoom lens at a wide-angle end,
Fnom＝(Fnot×Fnow) 1/2 ，
fnot: the F-number of the zoom lens at the telephoto end,
fnow: an F-number of the zoom lens at the wide-angle end.
The conditional expression (9) is a conditional expression for specifying a ratio between the magnification ratio of the zoom lens and the F value at the intermediate focal length position. By satisfying the conditional expression (9), a wide angle and high magnification are easily achieved, and a zoom lens having a large amount of peripheral light and high optical performance is easily obtained.
On the other hand, when the numerical value of conditional expression (9) is equal to or less than the lower limit, the zoom ratio is small or the F value is dim, so that the total length can be easily reduced in size, and the peripheral light amount can be easily ensured regardless of the present invention. On the other hand, when the numerical value of conditional expression (9) is equal to or greater than the upper limit value, the total length is likely to be increased in size because the magnification ratio is high or the F value is bright. Therefore, it is difficult to secure a sufficient amount of peripheral light.
2. Image pickup apparatus
Next, an imaging apparatus according to the present invention will be described. An imaging device according to the present invention is characterized by comprising: the zoom lens according to the present invention described above 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.
Here, the imaging element and the like are not particularly limited, and a solid-state imaging element such as a CCD (Charge Coupled device) sensor or a CMOS (Complementary Metal Oxide semiconductor) sensor may be used. The imaging device according to the present invention is suitable for imaging devices using these solid-state imaging elements, such as digital cameras and video cameras. The imaging device may be a lens-fixed type in which a lens is fixed to a housing, or may be a lens-replaceable type such as a single lens reflex camera or a micro single camera. In particular, the present invention relates to a zoom lens capable of securing a back focal length suitable for an interchangeable lens system. Therefore, the present invention is suitable for an imaging apparatus such as a single lens reflex camera including an optical viewfinder, a phase difference sensor, a mirror for branching light among these components, and the like.
Next, the present invention will be specifically described with reference to examples. However, the present invention is not limited to the following examples.
[ example 1] A method for producing a polycarbonate
(1) Optical structure of zoom lens
Fig. 1 is a lens cross-sectional view at infinity focusing at the wide-angle end of a zoom lens according to embodiment 1 of the present invention. The zoom lens includes, in order from an object side: a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, a third lens group G3 having positive refractive power, a fourth lens group G4 having positive refractive power, a fifth lens group G5 having negative refractive power, and a sixth lens group G6 having positive refractive power. The aperture stop S is disposed adjacent to the third lens group G3 on the object side of the third lens group G3. Zooming is performed by changing the interval on the optical axis between the lens groups as described later.
The structure of each lens group will be explained below. The first lens group G1 includes, in order from the object side, a cemented lens formed by a negative meniscus lens L1 with the convex surface facing the object side cemented with a double convex lens L2, and a positive meniscus lens L3 with the convex surface facing the object side.
The second lens group G2 includes, in order from the object side: a negative meniscus lens L4 with the convex surface facing the object side, a biconcave lens L5, a biconvex lens L6, and a negative meniscus lens L7 with the convex surface facing the image side. The negative meniscus lens L4 and the negative meniscus lens L7 are both glass molded type aspherical lenses having aspherical surfaces on both sides.
The third lens group G3 includes, in order from the object side, a biconvex lens L8 and a cemented lens formed by a biconvex lens L9 and a biconcave lens L10 cemented together. The lenticular lens L8 is a glass molded aspherical lens having aspherical surfaces on both sides.
The fourth lens group G4 includes, in order from the object side, a double convex lens L11, and a cemented lens formed by a negative meniscus lens L12 having a convex surface facing the object side cemented with a double convex lens L13. The lenticular lens L11 is a glass molded aspherical lens having aspherical surfaces on both sides.
The fifth lens group G5 is composed of a fifth a lens group G5A having negative refractive power, and a fifth B lens group G5B having positive refractive power. The fifth a lens group G5A is configured to be movable in a direction perpendicular to the optical axis. In the case where the zoom lens vibrates due to hand shake or the like, the fifth a lens group is moved in a direction perpendicular to the optical axis to correct the image position, whereby image shake caused by the vibration can be corrected.
The fifth a lens group G5A is composed of a cemented lens in which a positive meniscus lens L14 having a convex surface facing the image side and a biconcave lens L15 are cemented in this order from the object side. The fifth B lens group G5B includes, in order from the object side, a negative meniscus lens L16 with the convex surface facing the image side, and a positive meniscus lens L17 with the convex surface facing the object side.
The sixth lens group G6 includes, in order from the object side, a double convex lens L18, a cemented lens formed by a negative meniscus lens L19 with the convex surface facing the object side and a positive meniscus lens L20 with the convex surface facing the object side cemented together. The lenticular lens L18 is a glass molded aspherical lens having aspherical surfaces on both sides.
Upon zooming from the wide-angle end to the telephoto end, the first lens group G1 moves toward the object side, the second lens group G2 moves toward the image side first and then moves toward the object side, the third lens group G3 moves toward the object side, the fourth lens group G4 moves toward the object side, the fifth lens group G5 moves toward the object side, and the sixth lens group G6 moves toward the object side. Upon zooming, the fourth lens group G4 and the sixth lens group G6 move along the same trajectory.
Focusing from an infinity object toward a close object is performed by moving the second lens group G2 toward the object side.
The "IP" shown in fig. 1 is an image forming surface, and specifically indicates an image pickup surface of a solid-state image pickup device such as a CCD sensor or a CMOS sensor, a film surface of a silver halide film, or the like. Although not shown, a parallel flat plate having no substantial refractive power, such as a glass cover plate, may be provided on the object side of the image forming surface IP. These points are the same in the cross-sectional views of the lenses shown in the other embodiments, and therefore the description thereof will be omitted below.
(2) Numerical example
Next, a numerical example to which specific numerical values of the zoom lens are applied will be described. Table 1 shows surface data of the zoom lens. In table 1, "surface number" indicates the order of lens surfaces from the object side, "R" indicates the radius of curvature of the lens surfaces, "D" indicates the interval on the optical axis of the lens surfaces, "Nd" indicates the refractive index with respect to the D-line (wavelength λ =587.6 nm), and "ABV" indicates the abbe number with respect to the D-line. In addition, "ASPH" shown in the column following the surface number indicates that the lens surface is an aspherical surface, and "STOP" indicates an aperture STOP. Further, the columns of the intervals on the optical axis of the lens surface are indicated as "D (0)", "D (5)", and the like, which means that the intervals on the optical axis of the lens surface are variable intervals that change upon zooming. In each table, all units of length are "mm", and all units of angle of view are "°". In addition, "0" and "∞ (infinity)" of the curvature radius indicate planes.
Table 2 is a specification table of the zoom lens. The specification table shows a focal length "F", an F value "Fno", a half angle of view "ω", and an image height "Y" of the zoom lens at infinity focusing. Table 2 shows values of the wide-angle end, the first intermediate focal length position, the second intermediate focal length position, and the telephoto end in this order from the left side. The first intermediate focal length position and the second intermediate focal length position correspond to "fm1" and "fm2" described in the above embodiments.
The variable intervals on the optical axis of the zoom lens at infinity focusing are shown in table 3. In table 3, values at the wide angle end, the first intermediate focal length position, the second intermediate focal length position, and the telephoto end are shown in this order from the left side. In addition, "INF" in the table represents "∞ (infinity)".
Table 4 shows the variable intervals on the optical axis of the zoom lens when focusing on an approaching object whose shooting distance (imaging distance) is 1 m. Table 4 shows respective values of the wide angle end, the first intermediate focal length position, the second intermediate focal length position, and the telephoto end. In addition, "INF" in the table represents "∞ (infinity)".
Table 5 shows the focal lengths of the respective lens groups constituting the zoom lens.
Table 6 shows aspheric coefficients of the respective aspheric surfaces. The aspherical surface coefficient is a value when each aspherical surface shape is defined by the following equation. Table 49 shows the values of conditional expressions (1) to (9). Table 51 shows values of variables necessary for obtaining the values of conditional expressions (1) to (9).
X(Y)＝CY 2 /[1+{1-(1+K)·C 2 Y 2 } 1/2 ]+A4·Y 4 +A6·Y 6 +A8·Y 8 +A10·Y 10 +A12·Y 12
Wherein, in Table 6, "E-a" represents ". Times.10 -a ". In the above formula, "X" is a displacement amount from a reference plane in the optical axis direction, "C" is a curvature at a vertex of the plane (C =1/R, "R" is a curvature radius of the lens surface), "Y" is a height from the optical axis in a direction perpendicular to the optical axis, "K" is a conical coefficient, and "An" is An aspheric coefficient of n times.
The matters related to these tables are the same for the tables shown in the other embodiments, and therefore, the description thereof will be omitted below.
[ Table 1]
Figure BDA0001876899920000181
Figure BDA0001876899920000191
[ Table 2]
Figure BDA0001876899920000192
[ Table 3]
Variable spacing [ in infinity focusing ]
Figure BDA0001876899920000193
[ Table 4]
Variable spacing [ when shooting distance 1m is focused ]
Figure BDA0001876899920000194
[ Table 5]
Figure BDA0001876899920000195
Figure BDA0001876899920000201
[ Table 6]
Coefficient of aspheric surface
Figure BDA0001876899920000202
Fig. 2 to 5 are longitudinal aberration diagrams in infinity focusing at the wide angle end, the first intermediate focal length position, the second intermediate focal length position, and the telephoto end of the zoom lens according to example 1. The longitudinal aberration diagrams shown in the respective diagrams are spherical aberration (mm), astigmatism (mm), and distortion aberration (%) in order from the left side toward the drawing plane. In the graph showing the spherical aberration, the ordinate represents the ratio to the open F value, the abscissa represents defocus, the solid line represents the spherical aberration of the d-line (wavelength 587.56 nm), and the broken line represents the spherical aberration of the g-line (wavelength 435.84 nm). In the graph showing astigmatism, the vertical axis represents a half view angle, the horizontal axis represents defocus, the solid line represents sagittal image plane (ds) with respect to d-line, and the broken line represents meridional image plane (dm) with respect to d-line. In the figure showing the distortion aberration, the vertical axis represents the half angle of view, and the horizontal axis represents the distortion aberration. The matters related to these longitudinal aberration diagrams are the same as those in the longitudinal aberration diagrams shown in other embodiments, and therefore, the description thereof will be omitted below.
[ example 2]
(1) Optical structure of zoom lens
Fig. 6 is a lens cross-sectional view at infinity focusing at the wide-angle end of a zoom lens according to embodiment 2 of the present invention. The zoom lens includes, in order from an object side: a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, a third lens group G3 having a positive refractive power, a fourth lens group G4 having a positive refractive power, a fifth lens group G5 having a negative refractive power, and a sixth lens group G6 having a negative refractive power. The aperture stop S is disposed on the object side of the third lens group G3 adjacent to the third lens group G3. Zooming is performed by changing the interval on the optical axis between the lens groups as described later.
The structure of each lens group will be explained below. The first lens group G1 includes, in order from the object side, a cemented lens formed by a negative meniscus lens L1 with the convex surface facing the object side cemented with a double convex lens L2, and a positive meniscus lens L3 with the convex surface facing the object side.
The second lens group G2 includes, in order from the object side, a biconcave lens L4, a biconcave lens L5, a biconvex lens L6, and a negative meniscus lens L7 with the convex surface facing the image side. The biconcave lens L4 and the negative meniscus lens L7 are both glass-molded aspherical lenses having aspherical surfaces on both sides.
The third lens group G3 includes, in order from the object side, a biconvex lens L8 and a cemented lens formed by a biconvex lens L9 and a biconcave lens L10 cemented together. The lenticular lens L8 is a glass molded aspherical lens having aspherical surfaces on both sides.
The fourth lens group G4 includes, in order from the object side, a double convex lens L11, and a cemented lens formed by a negative meniscus lens L12 having a convex surface facing the object side cemented with a double convex lens L13. The lenticular lens L11 is a glass molded aspherical lens having aspherical surfaces on both sides.
The fifth lens group G5 is composed of a fifth a lens group G5A having negative refractive power, and a fifth B lens group G5B having positive refractive power. The fifth a lens group G5A is configured to be movable in a direction perpendicular to the optical axis. When the zoom lens vibrates due to hand shake or the like, the fifth a lens group is moved in a direction perpendicular to the optical axis to correct the image position, and image shake caused by the vibration can be corrected.
The fifth a lens group G5A is composed of a cemented lens in which a positive meniscus lens L14 having a convex surface facing the image side and a biconcave lens L15 are cemented in this order from the object side. The fifth B lens group G5B includes, in order from the object side, a biconcave lens L16 and a positive meniscus lens L17 with the convex surface facing the object side.
The sixth lens group G6 includes, in order from the object side, a double convex lens L18, a cemented lens formed by a negative meniscus lens L19 with the convex surface facing the object side and a positive meniscus lens L20 with the convex surface facing the object side cemented together. The lenticular lens L18 is a glass molded aspherical lens having aspherical surfaces on both sides.
When zooming from the wide-angle end to the telephoto end, the first lens group G1 moves toward the object side, the second lens group G2 moves toward the image side first, then moves toward the object side, and then moves toward the image side again, the third lens group G3 moves toward the object side, the fourth lens group G4 moves toward the object side, the fifth lens group G5 moves toward the object side, and the sixth lens group G6 moves toward the object side. Upon zooming, the fourth lens group G4 and the sixth lens group G6 move along the same trajectory.
Focusing from an infinity object toward a close object is performed by moving the second lens group G2 toward the object side.
(2) Numerical examples
Next, a numerical example to which specific numerical values of the zoom lens are applied will be described. The surface data of the zoom lens are shown in table 7, and the specification table of the zoom lens is shown in table 8. Table 9 shows the variable interval on the optical axis of the zoom lens at the time of infinity focusing, and table 10 shows the variable interval on the optical axis of the zoom lens at the time of focusing toward an approaching object having a shooting distance (image pickup distance) of 1 m. Table 11 shows the focal lengths of the respective lens groups constituting the zoom lens. Table 12 shows aspheric coefficients of the respective aspheric surfaces. Table 49 shows the values of conditional expressions (1) to (9). Table 51 shows values of variables necessary for obtaining the values of conditional expressions (1) to (9). Fig. 7 to 10 show longitudinal aberration diagrams in infinity focusing at the wide-angle end, the first intermediate focal length position, the second intermediate focal length position, and the telephoto end of the zoom lens according to example 2, respectively.
[ Table 7]
Figure BDA0001876899920000221
Figure BDA0001876899920000231
[ Table 8]
Figure BDA0001876899920000232
[ Table 9]
Variable spacing [ in infinity focusing ]
Figure BDA0001876899920000233
[ Table 10]
Variable interval [ when focusing at shooting distance 1m ]
Figure BDA0001876899920000234
[ Table 11]
Figure BDA0001876899920000241
[ Table 12]
Coefficient of aspheric surface
Figure BDA0001876899920000242
[ example 3]
(1) Optical structure of zoom lens
Fig. 11 is a lens cross-sectional view at infinity focusing at the wide-angle end of a zoom lens according to embodiment 3 of the present invention. The zoom lens includes, in order from an object side: a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, a third lens group G3 having positive refractive power a fourth lens group G4 having positive refractive power, a fifth lens group G5 having negative refractive power, and a sixth lens group G6 having positive refractive power. The aperture stop S is disposed adjacent to the third lens group G3 on the object side of the third lens group G3.
The structure of each lens group will be described below. The first lens group G1 includes, in order from the object side, a cemented lens formed by a negative meniscus lens L1 with the convex surface facing the object side cemented with a double convex lens L2, and a positive meniscus lens L3 with the convex surface facing the object side.
The second lens group G2 includes, in order from the object side, a biconcave lens L4, a biconcave lens L5, a biconvex lens L6, and a negative meniscus lens L7 with the convex surface facing the image side. The biconcave lens L4 and the negative meniscus lens L7 are both glass-molded aspherical lenses having aspherical surfaces on both sides.
The third lens group G3 includes, in order from the object side, a biconvex lens L8 and a cemented lens formed by a biconvex lens L9 and a biconcave lens L10 cemented together. The lenticular lens L8 is a glass molded aspherical lens having aspherical surfaces on both sides.
The fourth lens group G4 includes, in order from the object side, a double convex lens L11, and a cemented lens formed by a negative meniscus lens L12 having a convex surface facing the object side cemented with a double convex lens L13. The lenticular lens L11 is a glass molded aspherical lens having aspherical surfaces on both sides.
The fifth lens group G5 is composed of a fifth a lens group G5A having negative refractive power, and a fifth B lens group G5B having positive refractive power. The fifth a lens group G5A is configured to be movable in a direction perpendicular to the optical axis. When the zoom lens vibrates due to hand shake or the like, the fifth a lens group is moved in a direction perpendicular to the optical axis to correct the image position, and image shake caused by the vibration can be corrected.
The fifth a lens group G5A is composed of a cemented lens in which a positive meniscus lens L14 having a convex surface facing the image side and a biconcave lens L15 are cemented in this order from the object side. The fifth B lens group G5B includes, in order from the object side, a negative meniscus lens L16 with the convex surface facing the object side, and a positive meniscus lens L17 with the convex surface facing the object side.
The sixth lens group G6 includes, in order from the object side, a cemented lens formed by a double convex lens L18, a negative meniscus lens L19 with the convex surface facing the object side, and a positive meniscus lens L20 with the convex surface facing the object side cemented together. The lenticular lens L18 is a glass molded aspherical lens having aspherical surfaces on both sides.
Upon zooming from the wide-angle end to the telephoto end, the first lens group G1 moves toward the object side, the second lens group G2 moves toward the image side first, then moves toward the object side, and then moves toward the image side again, the third lens group G3 moves toward the object side, the fourth lens group G4 moves toward the object side, the fifth lens group G5 moves toward the object side, and the sixth lens group G6 moves toward the object side. Upon zooming, the fourth lens group G4 and the sixth lens group G6 move along the same trajectory.
Focusing from an infinity object toward a close object is performed by moving the second lens group G2 toward the object.
(2) Numerical example
Next, a numerical example to which specific numerical values of the zoom lens are applied will be described. The surface data of the zoom lens are shown in table 13, and the specification table of the zoom lens is shown in table 14. Table 15 shows the variable intervals on the optical axis of the zoom lens in infinity focus, and table 16 shows the variable intervals on the optical axis of the zoom lens in focus toward an approaching object whose shooting distance (image pickup distance) is 1 m. Table 17 shows the focal lengths of the respective lens groups constituting the zoom lens. Table 18 shows aspheric coefficients of the respective aspheric surfaces. Table 49 shows the values of conditional expressions (1) to (9). Table 51 shows values of variables necessary for obtaining the values of conditional expressions (1) to (9). Fig. 12 to 15 show longitudinal aberration diagrams in infinity focusing at the wide angle end, the first intermediate focal length position, the second intermediate focal length position, and the telephoto end of the zoom lens according to example 3.
[ Table 13]
Figure BDA0001876899920000261
Figure BDA0001876899920000271
[ Table 14]
Figure BDA0001876899920000272
[ Table 15]
Variable spacing [ in infinity focusing ]
Figure BDA0001876899920000273
[ Table 16]
Variable spacing [ when shooting distance 1m is focused ]
Figure BDA0001876899920000274
[ Table 17]
Figure BDA0001876899920000275
Figure BDA0001876899920000281
[ Table 18]
Coefficient of aspheric surface
Figure BDA0001876899920000282
[ example 4]
(1) Optical structure of zoom lens
Fig. 16 is a lens cross-sectional view at infinity focusing at the wide-angle end of a zoom lens according to embodiment 4 of the present invention. The zoom lens includes, in order from an object side: a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, a third lens group G3 having positive refractive power, a fourth lens group G4 having positive refractive power, a fifth lens group G5 having negative refractive power, and a sixth lens group G6 having positive refractive power. The aperture stop S is disposed on the object side of the third lens group G3 adjacent to the third lens group G3.
The structure of each lens group will be explained below. The first lens group G1 includes, in order from the object side, a cemented lens formed by a negative meniscus lens L1 with the convex surface facing the object side cemented with a double convex lens L2, and a positive meniscus lens L3 with the convex surface facing the object side.
The second lens group G2 includes, in order from the object side, a biconcave lens L4, a biconcave lens L5, a biconvex lens L6, and a negative meniscus lens L7 with the convex surface facing the image side. The biconcave lens L4 and the negative meniscus lens L7 are both glass-molded aspherical lenses having aspherical surfaces on both sides.
The third lens group G3 includes, in order from the object side, a biconvex lens L8 and a cemented lens formed by a biconvex lens L9 and a biconcave lens L10 cemented together. The lenticular lens L8 is a glass molded aspherical lens having aspherical surfaces on both sides.
The fourth lens group G4 includes, in order from the object side, a cemented lens formed by a double convex lens L11, a negative meniscus lens L12 having a convex surface facing the object side, and a double convex lens L13 cemented together. The lenticular lens L11 is a glass molded aspherical lens having aspherical surfaces on both sides.
The fifth lens group G5 is composed of a fifth a lens group G5A having negative refractive power, and a fifth B lens group G5B having positive refractive power. The fifth a lens group G5A is configured to be movable in a direction perpendicular to the optical axis. When the zoom lens vibrates due to hand shake or the like, the fifth a lens group is moved in a direction perpendicular to the optical axis to correct the image position, and image shake caused by the vibration can be corrected.
The fifth a lens group G5A is composed of a cemented lens in which a positive meniscus lens L14 having a convex surface facing the image side and a biconcave lens L15 are cemented in this order from the object side. The fifth B lens group G5B includes, in order from the object side, a biconcave lens L16 and a positive meniscus lens L17 with the convex surface facing the object side.
The sixth lens group G6 includes, in order from the object side, a cemented lens formed by a double convex lens L18, a negative meniscus lens L19 with the convex surface facing the object side, and a positive meniscus lens L20 with the convex surface facing the object side cemented together. The lenticular lens L18 is a glass molded aspherical lens having aspherical surfaces on both sides.
Upon zooming from the wide-angle end to the telephoto end, the first lens group G1 moves toward the object side, the second lens group G2 moves toward the image side first, then moves toward the object side, and then moves toward the image side again, the third lens group G3 moves toward the object side, the fourth lens group G4 moves toward the object side, the fifth lens group G5 moves toward the object side, and the sixth lens group G6 moves toward the object side. Upon zooming, the fourth lens group G4 and the sixth lens group G6 move along the same trajectory.
Focusing from an infinity object toward a close object is performed by moving the second lens group G2 toward the object side.
(2) Numerical example
Next, a numerical example to which specific numerical values of the zoom lens are applied will be described. Table 19 shows surface data of the zoom lens, and table 20 shows a specification table of the zoom lens. Table 21 shows the variable intervals on the optical axis of the zoom lens in infinity focus, and table 22 shows the variable intervals on the optical axis of the zoom lens in focus toward an approaching object whose shooting distance (image pickup distance) is 1 m. Table 23 shows the focal lengths of the respective lens groups constituting the zoom lens. Table 24 shows aspheric coefficients of the respective aspheric surfaces. Table 49 shows the values of conditional expressions (1) to (9). Table 51 shows values of variables necessary for obtaining the values of conditional expressions (1) to (9). Fig. 17 to 20 show longitudinal aberration diagrams in infinity focusing at the wide angle end, the first intermediate focal length position, the second intermediate focal length position, and the telephoto end of the zoom lens according to example 4, respectively.
[ Table 19]
Figure BDA0001876899920000291
Figure BDA0001876899920000301
[ Table 20]
Figure BDA0001876899920000311
[ Table 21]
Variable spacing [ in infinity focusing ]
Figure BDA0001876899920000312
[ Table 22]
Variable spacing [ when shooting distance 1m is focused ]
Figure BDA0001876899920000313
[ Table 23]
Figure BDA0001876899920000314
[ Table 24]
Coefficient of aspheric surface
Figure BDA0001876899920000321
[ example 5]
(1) Optical structure of zoom lens
Fig. 21 is a lens cross-sectional view at infinity focusing at the wide-angle end of a zoom lens according to embodiment 5 of the present invention. The zoom lens includes, in order from an object side: a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, a third lens group G3 having positive refractive power, a fourth lens group G4 having positive refractive power, a fifth lens group G5 having negative refractive power, and a sixth lens group G6 having positive refractive power. The aperture stop S is disposed adjacent to the third lens group G3 on the object side of the third lens group G3.
The structure of each lens group will be explained below. The first lens group G1 includes, in order from the object side, a cemented lens formed by a negative meniscus lens L1 having a convex surface facing the object side cemented with a double convex 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 biconcave lens L4, a biconcave lens L5, a biconvex lens L6, and a negative meniscus lens L7 with the convex surface facing the image side. The biconcave lens L4 and the negative meniscus lens L7 are both glass-molded aspherical lenses having aspherical surfaces on both sides.
The third lens group G3 includes, in order from the object side, a biconvex lens L8 and a cemented lens formed by a biconvex lens L9 and a biconcave lens L10 cemented together. The lenticular lens L8 is a glass molded aspherical lens having aspherical surfaces on both sides.
The fourth lens group G4 includes, in order from the object side, a double convex lens L11, and a cemented lens formed by a negative meniscus lens L12 having a convex surface facing the object side cemented with a double convex lens L13. The lenticular lens L11 is a glass molded aspherical lens having aspherical surfaces on both sides.
The fifth lens group G5 is composed of a fifth a lens group G5A having a negative refractive power, and a fifth B lens group G5B having a negative refractive power. The fifth a lens group G5A is configured to be movable in a direction perpendicular to the optical axis. When the zoom lens vibrates due to hand shake or the like, the fifth a lens group is moved in a direction perpendicular to the optical axis to correct the image position, and image shake caused by the vibration can be corrected.
The fifth a lens group G5A is composed of a cemented lens in which a positive meniscus lens L14 having a convex surface facing the image side and a biconcave lens L15 are cemented in this order from the object side. The fifth B lens group G5B includes, in order from the object side, a biconcave lens L16 and a positive meniscus lens L17 with the convex surface facing the object side.
The sixth lens group G6 includes, in order from the object side, a cemented lens formed by a double convex lens L18, a negative meniscus lens L19 with the convex surface facing the object side, and a positive meniscus lens L20 with the convex surface facing the object side cemented together. The lenticular lens L18 is a glass molded aspherical lens having aspherical surfaces on both sides.
Upon zooming from the wide-angle end to the telephoto end, the first lens group G1 moves toward the object side, the second lens group G2 moves toward the image side first and then moves toward the object side, the third lens group G3 moves toward the object side, the fourth lens group G4 moves toward the object side, the fifth lens group G5 moves toward the object side, and the sixth lens group G6 moves toward the object side. Upon zooming, the fourth lens group G4 and the sixth lens group G6 move along the same trajectory.
Focusing from an infinity object toward a close object is performed by moving the second lens group G2 toward the object side.
(2) Numerical example
Next, a numerical example to which specific numerical values of the zoom lens are applied will be described. Table 25 shows surface data of the zoom lens, and table 26 shows a specification table of the zoom lens. Table 27 shows the variable intervals on the optical axis of the zoom lens in infinity focus, and table 28 shows the variable intervals on the optical axis of the zoom lens in focus toward an approaching object whose shooting distance (image pickup distance) is 1 m. Table 29 shows the focal lengths of the respective lens groups constituting the zoom lens. Table 30 shows aspheric coefficients of the respective aspheric surfaces. Table 50 shows the values of conditional expressions (1) to (9). Table 52 shows values of variables necessary for obtaining the values of conditional expressions (1) to (9). Fig. 22 to 25 show longitudinal aberration diagrams in infinity focusing at the wide-angle end, the first intermediate focal length position, the second intermediate focal length position, and the telephoto end of the zoom lens according to example 5.
[ Table 25]
Figure BDA0001876899920000331
Figure BDA0001876899920000341
[ Table 26]
Figure BDA0001876899920000342
[ Table 27]
Variable spacing [ in infinity focusing ]
Figure BDA0001876899920000351
[ Table 28]
Variable spacing [ when shooting distance 1m is focused ]
Figure BDA0001876899920000352
[ Table 29]
Figure BDA0001876899920000353
[ Table 30]
Coefficient of aspheric surface
Figure BDA0001876899920000354
Figure BDA0001876899920000361
[ example 6]
(1) Optical structure of zoom lens
Fig. 26 is a lens cross-sectional view in infinity focusing at the wide-angle end of a zoom lens according to embodiment 6 of the present invention. The zoom lens includes, in order from an object side: a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, a third lens group G3 having positive refractive power, a fourth lens group G4 having positive refractive power, a fifth lens group G5 having negative refractive power, a sixth lens group G6 having positive refractive power, and a seventh lens group G7 having positive refractive power. The aperture stop S is disposed on the object side of the third lens group G3 adjacent to the third lens group G3.
The structure of each lens group will be explained below. The first lens group G1 includes, in order from the object side, a cemented lens formed by a negative meniscus lens L1 having a convex surface facing the object side cemented with a double convex 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 with the convex surface facing the object side, a biconcave lens L5, a biconvex lens L6, and a negative meniscus lens L7 with the convex surface facing the image side. The negative meniscus lens L4 and the negative meniscus lens L7 are both glass molded type aspherical lenses having aspherical surfaces on both sides.
The third lens group G3 includes, in order from the object side, a biconvex lens L8 and a cemented lens formed by a biconvex lens L9 and a biconcave lens L10 cemented together. The lenticular lens L8 is a glass molded aspherical lens having aspherical surfaces on both sides.
The fourth lens group G4 includes, in order from the object side, a double convex lens L11, and a cemented lens formed by a negative meniscus lens L12 having a convex surface facing the object side cemented with a double convex lens L13. The lenticular lens L11 is a glass molded aspherical lens having aspherical surfaces on both sides.
The fifth lens group G5 is composed of a fifth a lens group G5A having a negative refractive power, and a fifth B lens group G5B having a negative refractive power. The fifth a lens group G5A is configured to be movable in a direction perpendicular to the optical axis. When the zoom lens vibrates due to hand shake or the like, the fifth a lens group is moved in a direction perpendicular to the optical axis to correct the image position, and image shake caused by the vibration can be corrected.
The fifth a lens group G5A is composed of a cemented lens in which a positive meniscus lens L14 having a convex surface facing the image side and a biconcave lens L15 are cemented in this order from the object side. The fifth B lens group G5B includes, in order from the object side, a negative meniscus lens L16 with the convex surface facing the image side, and a positive meniscus lens L17 with the convex surface facing the object side.
The sixth lens group G6 includes, in order from the object side, a double convex lens L18, a cemented lens formed by a negative meniscus lens L19 with the convex surface facing the object side and a positive meniscus lens L20 with the convex surface facing the object side cemented together. The lenticular lens L18 is a glass molded aspherical lens having aspherical surfaces on both sides.
The seventh lens group G7 includes, in order from the object side, a positive meniscus lens having a convex surface facing the image side.
Upon zooming from the wide-angle end to the telephoto end, the first lens group G1 moves toward the object side, the second lens group G2 moves toward the image side first and then moves toward the object side, the third lens group G3 moves toward the object side, the fourth lens group G4 moves toward the object side, the fifth lens group G5 moves toward the object side, the sixth lens group G6 moves toward the object side, and the seventh lens group G7 is fixed on the optical axis. Upon zooming, the fourth lens group G4 and the sixth lens group G6 move along the same trajectory.
Focusing from an infinity object toward a close object is performed by moving the second lens group G2 toward the object side.
(2) Numerical examples
Next, a numerical example to which specific numerical values of the zoom lens are applied will be described. The surface data of the zoom lens are shown in table 31, and the specification table of the zoom lens is shown in table 32. Table 33 shows the variable intervals on the optical axis of the zoom lens in infinity focus, and table 34 shows the variable intervals on the optical axis of the zoom lens in focus toward an approaching object whose shooting distance (image pickup distance) is 1 m. Table 35 shows the focal lengths of the respective lens groups constituting the zoom lens. Table 36 shows aspheric coefficients of the respective aspheric surfaces. Table 50 shows the values of conditional expressions (1) to (9). Table 52 shows values of variables necessary for obtaining the values of conditional expressions (1) to (9). Fig. 27 to 30 show longitudinal aberration diagrams in infinity focusing at the wide-angle end, the first intermediate focal length position, the second intermediate focal length position, and the telephoto end of the zoom lens according to example 6, respectively.
[ Table 31]
Figure BDA0001876899920000371
Figure BDA0001876899920000381
[ Table 32]
Figure BDA0001876899920000382
[ Table 33]
Variable spacing [ in infinity focusing ]
Figure BDA0001876899920000391
[ Table 34]
Variable interval [ when focusing at shooting distance 1m ]
Figure BDA0001876899920000392
[ Table 35]
Figure BDA0001876899920000393
[ Table 36]
Coefficient of aspheric surface
Figure BDA0001876899920000394
Figure BDA0001876899920000401
[ example 7] A method for producing a polycarbonate
(1) Optical structure of zoom lens
Fig. 31 is a lens cross-sectional view at infinity focusing at the wide-angle end of a zoom lens according to embodiment 7 of the present invention. The zoom lens includes, in order from an object side: a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, a third lens group G3 having positive refractive power, a fourth lens group G4 having positive refractive power, a fifth lens group G5 having negative refractive power, a sixth lens group G6 having positive refractive power, and a seventh lens group G7 having negative refractive power. The aperture stop S is disposed adjacent to the third lens group G3 on the object side of the third lens group G3.
The structure of each lens group will be described below. The first lens group G1 includes, in order from the object side, a cemented lens formed by a negative meniscus lens L1 having a convex surface facing the object side cemented with a double convex 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 with the convex surface facing the object side, a biconcave lens L5, a biconvex lens L6, and a negative meniscus lens L7 with the convex surface facing the image side. The negative meniscus lens L4 and the negative meniscus lens L7 are both glass molded type aspherical lenses having aspherical surfaces on both sides.
The third lens group G3 includes, in order from the object side, a biconvex lens L8 and a cemented lens formed by a biconvex lens L9 and a biconcave lens L10 cemented together. The lenticular lens L8 is a glass molded aspherical lens having aspherical surfaces on both sides.
The fourth lens group G4 includes, in order from the object side, a double convex lens L11, and a cemented lens formed by a negative meniscus lens L12 having a convex surface facing the object side cemented with a double convex lens L13. The lenticular lens L11 is a glass molded aspherical lens having aspherical surfaces on both sides.
The fifth lens group G5 is composed of a fifth a lens group G5A having negative refractive power, and a fifth B lens group G5B having positive refractive power. The fifth a lens group G5A is configured to be movable in a direction perpendicular to the optical axis. When the zoom lens vibrates due to hand shake or the like, the fifth a lens group is moved in a direction perpendicular to the optical axis to correct the image position, and image shake caused by the vibration can be corrected.
The fifth a lens group G5A is composed of a cemented lens in which a positive meniscus lens L14 having a convex surface facing the image side and a biconcave lens L15 are cemented in this order from the object side. The fifth B lens group G5B includes, in order from the object side, a biconcave lens L16 and a positive meniscus lens L17 with the convex surface facing the object side.
The sixth lens group G6 includes, in order from the object side, a cemented lens formed by a double convex lens L18, a negative meniscus lens L19 with the convex surface facing the object side, and a positive meniscus lens L20 with the convex surface facing the object side cemented together. The lenticular lens L18 is a glass molded aspherical lens having aspherical surfaces on both sides.
The seventh lens group G7 includes, in order from the object side, a negative meniscus lens having a convex surface facing the object side.
Upon zooming from the wide-angle end to the telephoto end, the first lens group G1 moves toward the object side, the second lens group G2 moves toward the object side after moving toward the image side first, and moves again toward the image side, the third lens group G3 moves toward the object side, the fourth lens group G4 moves toward the object side, the fifth lens group G5 moves toward the object side, the sixth lens group G6 moves toward the object side, and the seventh lens group G7 moves toward the object side. Upon zooming, the fourth lens group G4 and the sixth lens group G6 move along the same trajectory.
Focusing from an infinity object toward a close object is performed by moving the second lens group G2 toward the object side.
(2) Numerical example
Next, a numerical example to which specific numerical values of the zoom lens are applied will be described. Table 37 shows surface data of the zoom lens, and table 38 shows a specification table of the zoom lens. Table 39 shows the variable intervals on the optical axis of the zoom lens in infinity focus, and table 40 shows the variable intervals on the optical axis of the zoom lens in focus toward an approaching object whose shooting distance (image pickup distance) is 1 m. Table 41 shows the focal lengths of the respective lens groups constituting the zoom lens. Table 42 shows aspheric coefficients of the respective aspheric surfaces. Table 50 shows the values of conditional expressions (1) to (9). Table 52 shows values of variables necessary for obtaining the values of conditional expressions (1) to (9). Fig. 32 to 35 are longitudinal aberration diagrams in infinity focusing at the wide angle end, the first intermediate focal length position, the second intermediate focal length position, and the telephoto end of the zoom lens according to example 7.
[ Table 37]
Figure BDA0001876899920000411
Figure BDA0001876899920000421
[ Table 38]
Figure BDA0001876899920000422
[ Table 39]
Variable spacing [ in infinity focusing ]
Figure BDA0001876899920000431
[ Table 40]
Variable interval [ when focusing at shooting distance 1m ]
Figure BDA0001876899920000432
[ Table 41]
Figure BDA0001876899920000433
[ Table 42]
Figure BDA0001876899920000434
Figure BDA0001876899920000441
[ example 8]
(1) Optical structure of zoom lens
Fig. 36 is a lens cross-sectional view at infinity focusing at the wide-angle end of a zoom lens according to embodiment 8 of the present invention. The zoom lens includes, in order from an object side: a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, a third lens group G3 having positive refractive power, a fourth lens group G4 having positive refractive power, a fifth lens group G5 having negative refractive power, and a sixth lens group G6 having positive refractive power. The aperture stop is disposed adjacent to the object side of the third lens group G3.
The structure of each lens group will be explained below. The first lens group G1 includes, in order from the object side, a cemented lens formed by a negative meniscus lens L1 with the convex surface facing the object side cemented with a positive meniscus lens L2 with the convex surface facing the object side, and a positive meniscus lens L3 with the convex surface facing the object side.
The second lens group G2 includes, in order from the object side: a negative meniscus lens L4 with the convex surface facing the object side, a cemented lens cemented by a biconcave lens L5 and a biconvex lens L6, and a negative meniscus lens L7 with the convex surface facing the image side. The negative meniscus lens L4 is a composite resin type aspherical lens in which a composite resin film molded into an aspherical shape is bonded to the object side surface. The negative meniscus lens L7 is a glass molded aspherical lens having aspherical surfaces on both sides.
The third lens group G3 includes, in order from the object side, a biconvex lens L8 and a negative meniscus lens L9 with the convex surface facing the object side. The lenticular lens L8 is a glass molded aspherical lens having aspherical surfaces on both sides.
The fourth lens group G4 includes, in order from the object side: a cemented lens formed by a negative meniscus lens L10 with the convex surface facing the object side cemented with a double convex lens L11, and a positive meniscus lens L12 with the convex surface facing the image side. The positive meniscus lens L12 is a composite resin type aspherical lens formed by laminating a composite resin film molded into an aspherical shape on the object side.
The fifth lens group G5 is composed of a fifth a lens group G5A having a negative refractive power, and a fifth B lens group G5B having a negative refractive power. The fifth a lens group G5A is configured to be movable in a direction perpendicular to the optical axis. When the zoom lens vibrates due to hand shake or the like, the fifth a lens group is moved in a direction perpendicular to the optical axis to correct the image position, and image shake caused by the vibration can be corrected.
The fifth a lens group G5A is composed of a cemented lens in which a positive meniscus lens L13 having a convex surface facing the image side and a biconcave lens L14 are cemented in this order from the object side. The fifth B lens group G5B includes, in order from the object side, a biconcave lens L15 and a positive meniscus lens L16 with the convex surface facing the object side.
The sixth lens group G6 includes, in order from the object side, a biconvex lens L17 and a cemented lens formed by a biconcave lens L18 and a biconvex lens L19 cemented together. The lenticular lens L17 is a glass molded aspherical lens having an aspherical image side surface.
Upon zooming from the wide-angle end to the telephoto end, the first lens group G1 moves toward the object side, the second lens group G2 moves toward the image side first and then moves toward the object side, the third lens group G3 moves toward the object side, the fourth lens group G4 moves toward the object side, the fifth lens group G5 moves toward the object side, and the sixth lens group G6 moves toward the object side. Upon zooming, the fourth lens group G4 and the sixth lens group G6 move along the same trajectory.
Focusing from an infinity object toward a close object is performed by moving the second lens group G2 toward the object side.
(2) Numerical example
Next, a numerical example to which specific numerical values of the zoom lens are applied will be described. Table 43 shows surface data of the zoom lens, and table 44 shows a specification table of the zoom lens. Table 45 shows the variable intervals on the optical axis of the zoom lens in infinity focus, and table 46 shows the variable intervals on the optical axis of the zoom lens in focus toward an approaching object whose shooting distance (image pickup distance) is 1 m. Table 47 shows the focal lengths of the respective lens groups constituting the zoom lens. Table 48 shows aspheric coefficients of the respective aspheric surfaces. Table 50 shows the values of conditional expressions (1) to (9). Table 52 shows values of variables necessary for obtaining the values of conditional expressions (1) to (9). Fig. 37 to 40 show longitudinal aberration diagrams in infinity focusing at the wide-angle end, the first intermediate focal length position, the second intermediate focal length position, and the telephoto end of the zoom lens according to example 8, respectively.
[ Table 43]
Figure BDA0001876899920000451
Figure BDA0001876899920000461
[ Table 44]
Figure BDA0001876899920000462
[ Table 45]
Variable spacing [ in infinity focusing ]
Figure BDA0001876899920000471
[ Table 46]
Variable interval [ when focusing at shooting distance 1m ]
Figure BDA0001876899920000472
[ Table 47]
Figure BDA0001876899920000473
[ Table 48]
Coefficient of aspheric surface
Figure BDA0001876899920000474
[ Table 49]
Figure BDA0001876899920000481
[ Table 50]
Figure BDA0001876899920000482
[ Table 51]
Figure BDA0001876899920000483
Figure BDA0001876899920000491
[ Table 52]
Figure BDA0001876899920000492
(availability in industry)
According to the present invention, a zoom lens having a large amount of peripheral light, high optical performance, and a high magnification ratio, and an image pickup apparatus including the zoom lens can be provided. The zoom lens is suitable for interchangeable lenses of image pickup apparatuses using an interchangeable lens system, such as single lens reflex cameras and micro single cameras. The zoom lens realizes a wide angle of view, for example, a half angle of view of about 40 degrees, and also has a prescribed back focal length in the wide angle end, and is therefore particularly suitable for an interchangeable lens of a single lens reflex camera.

Claims (12)

1. A zoom lens includes, in order from an object side: 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 positive refractive power, a fifth lens group having negative refractive power, and a sixth lens group, and intervals on optical axes of adjacent lens groups change upon zooming,
the zoom lens is characterized by satisfying the following conditional expression;
0.10≤f34w/|f5|≤0.75……(1)
-0.5≤fw/f5iw≤0.2……(2)
0.04≤|f2|/ft≤0.21……(6)
-6.0≤Cr2r/fw≤-0.9……(7)
wherein the content of the first and second substances,
f34w: a combined focal length of the third lens group and the fourth lens group at a wide-angle end;
f5: a focal length of the fifth lens group;
fw: a focal length of the zoom lens at a wide-angle end;
f5iw: a composite focal length from the fifth lens group at the wide-angle end to a lens group disposed on the most image side of the zoom lens;
f2: a focal length of the second lens group;
ft: the focal length of the zoom lens at the telephoto end;
cr2r: a radius of curvature of a surface of the second lens group closest to the image side.
2. A zoom lens includes, in order from an object side: 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 positive refractive power, a fifth lens group having negative refractive power, and a sixth lens group, and intervals on optical axes of adjacent lens groups change upon zooming,
the zoom lens is characterized in that the fourth lens group and the sixth lens group move along the same track during zooming and satisfy the following conditional expression;
0.10≤f34w/|f5|≤0.75……(1)
-0.5≤fw/f5iw≤0.2……(2)
-6.0≤Cr2r/fw≤-0.9……(7)
wherein the content of the first and second substances,
f34w: a combined focal length of the third lens group and the fourth lens group at a wide-angle end;
f5: a focal length of the fifth lens group;
fw: a focal length of the zoom lens at a wide-angle end;
f5iw: a composite focal length from the fifth lens group at the wide-angle end to a lens group disposed closest to the image side of the zoom lens;
cr2r: a radius of curvature of a surface of the second lens group closest to the image side.
3. A zoom lens includes, in order from an object side: 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 positive refractive power, a fifth lens group having negative refractive power, and a sixth lens group, and intervals on optical axes of adjacent lens groups change upon zooming,
the zoom lens is characterized in that the fourth lens group and the sixth lens group move along the same track during zooming and satisfy the following conditional expression;
0.10≤f34w/|f5|≤0.75……(1)
-0.35≤fw/f5iw≤0.2……(2)
wherein the content of the first and second substances,
f34w: a combined focal length of the third lens group and the fourth lens group at a wide-angle end;
f5: a focal length of the fifth lens group;
fw: a focal length of the zoom lens at a wide-angle end;
f5iw: a combined focal length from the fifth lens group at the wide-angle end to a lens group disposed on the most image side of the zoom lens.
4. Zoom lens according to any one of claims 1-3, characterized in that the following conditional expression is satisfied;
2.5≤f1/fw≤9.0……(3)
wherein, the first and the second end of the pipe are connected with each other,
f1: a focal length of the first lens group.
5. A zoom lens according to any one of claims 1-3, characterized in that the following conditional expression is satisfied;
4.0≤T3w/Y≤8.0……(4)
wherein the content of the first and second substances,
t3w: a distance on an optical axis from a most object side surface of the third lens group at a wide angle end to an image forming surface;
y: maximum image height at the wide-angle end.
6. A zoom lens according to any one of claims 1-3, characterized in that the following conditional expression is satisfied;
-0.10≤f345w/f6iw≤0.70……(5)
wherein the content of the first and second substances,
f345w: a composite focal length from the third lens group to the fifth lens group at a wide-angle end;
f6iw: and a combined focal length from the six lens groups at the wide-angle end to a lens group disposed closest to the image side among the zoom lenses.
7. Zoom lens according to any of claims 1-3,
the sixth lens group has positive refractive power.
8. Zoom lens according to any of claims 1-3,
and moving at least one of the third lens group and the fourth lens group on an optical axis so as to narrow an interval on the optical axis between the third lens group and the fourth lens group upon zooming from a wide-angle end to a telephoto end.
9. Zoom lens according to any of claims 1-3,
the fifth lens group includes, in order from the object side: a fifth A lens group having negative refractive power, a fifth B lens group having positive refractive power or negative refractive power;
the fifth a lens group is configured to be movable in a direction perpendicular to an optical axis.
10. Zoom lens according to any of claims 1-3,
the fifth lens group has at least two positive lenses.
11. Zoom lens according to any of claims 1-3,
at least any one of the third lens group and the fourth lens group has a positive lens on the most object side.
12. An imaging device is characterized by comprising:
a variable focus lens as claimed in any one of claims 1 to 11; and
and an image pickup element that converts an optical image formed by the zoom lens into an electric signal on an image side of the zoom lens.
CN201811403960.7A 2018-04-27 2018-11-23 Zoom lens and imaging device Active CN110412755B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202211244499.1A CN115657281A (en) 2018-04-27 2018-11-23 Zoom lens and imaging device

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2018085968A JP7032226B2 (en) 2018-04-27 2018-04-27 Zoom lens and image pickup device
JP2018-085968 2018-04-27

Related Child Applications (1)

Application Number Title Priority Date Filing Date
CN202211244499.1A Division CN115657281A (en) 2018-04-27 2018-11-23 Zoom lens and imaging device

Publications (2)

Publication Number Publication Date
CN110412755A CN110412755A (en) 2019-11-05
CN110412755B true CN110412755B (en) 2022-11-04

Family

ID=68358123

Family Applications (2)

Application Number Title Priority Date Filing Date
CN202211244499.1A Pending CN115657281A (en) 2018-04-27 2018-11-23 Zoom lens and imaging device
CN201811403960.7A Active CN110412755B (en) 2018-04-27 2018-11-23 Zoom lens and imaging device

Family Applications Before (1)

Application Number Title Priority Date Filing Date
CN202211244499.1A Pending CN115657281A (en) 2018-04-27 2018-11-23 Zoom lens and imaging device

Country Status (2)

Country Link
JP (1) JP7032226B2 (en)
CN (2) CN115657281A (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109298515B (en) * 2018-12-11 2023-11-21 浙江舜宇光学有限公司 Image pickup lens

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2014228711A (en) * 2013-05-22 2014-12-08 株式会社タムロン Zoom lens and imaging apparatus
CN106066530A (en) * 2015-04-22 2016-11-02 株式会社腾龙 Zoom lens and camera head

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4496460B2 (en) 2004-01-05 2010-07-07 ソニー株式会社 Zoom lens and imaging device
US7719773B2 (en) * 2007-11-12 2010-05-18 Ricoh Company, Ltd. Zoom lens unit and imaging apparatus
JP5052581B2 (en) 2008-12-24 2012-10-17 オリンパス株式会社 Zoom optical system and electronic imaging apparatus using the same
JP2012015593A (en) * 2010-06-29 2012-01-19 Nec Corp Telephone and auto-redial method
WO2012026088A1 (en) 2010-08-24 2012-03-01 パナソニック株式会社 Zoom lens system, interchangeable lens device, and camera system
KR101890304B1 (en) * 2011-11-04 2018-08-22 삼성전자주식회사 Zoom lens and photographing apparatus
JP5890065B2 (en) * 2013-03-27 2016-03-22 富士フイルム株式会社 Zoom lens and imaging device
WO2015146067A1 (en) 2014-03-28 2015-10-01 パナソニックＩｐマネジメント株式会社 Zoom-lens system, interchangeable-lens device, and camera system
JP6436656B2 (en) * 2014-06-11 2018-12-12 キヤノン株式会社 Zoom lens and imaging apparatus having the same
CN111880295B (en) * 2014-08-29 2022-12-09 株式会社尼康 Variable magnification optical system and optical apparatus

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2014228711A (en) * 2013-05-22 2014-12-08 株式会社タムロン Zoom lens and imaging apparatus
CN106066530A (en) * 2015-04-22 2016-11-02 株式会社腾龙 Zoom lens and camera head

Also Published As

Publication number Publication date
CN115657281A (en) 2023-01-31
JP7032226B2 (en) 2022-03-08
JP2019191445A (en) 2019-10-31
CN110412755A (en) 2019-11-05

Similar Documents

Publication Publication Date Title
US10976530B2 (en) Zoom lens and imaging apparatus
JP6577191B2 (en) Zoom lens and imaging device
JP6877212B2 (en) Zoom lens and imaging device
JP6377319B2 (en) Zoom lens and imaging device
JP6220555B2 (en) Zoom lens and imaging device
CN110832376B (en) Variable magnification optical system and optical device
CN110058391B (en) Variable magnification optical system and optical apparatus
CN107544129B (en) Zoom lens and imaging device
JP2014228807A5 (en)
JP6377320B2 (en) Zoom lens and imaging device
JP2014228812A5 (en)
JP2014228808A5 (en)
CN108369329B (en) Zoom lens and optical apparatus
CN109254389B (en) Zoom lens and image pickup apparatus
JP6299261B2 (en) Optical system and optical apparatus
CN107884917B (en) Variable magnification optical system and optical device
CN109387929B (en) Zoom lens and image pickup apparatus
CN110412755B (en) Zoom lens and imaging device
JP6268792B2 (en) Zoom lens, optical device, and zoom lens manufacturing method
US20180267278A1 (en) Variable magnification optical system, optical device, and method for producing variable magnification
US20180113285A1 (en) Variable magnification optical system, optical device, and production method for variable magnification optical system
US20170075093A1 (en) Variable power optical system, optical device, and method of manufacturing variable power optical system
US9453993B2 (en) Variable magnification optical system, optical device, and production method for variable magnification optical system
CN111580256B (en) Zoom lens and image pickup apparatus
CN115598809A (en) Zoom lens and imaging device

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant