JP6212264B2 - Zoom lens - Google Patents

Description

  The present invention relates to a zoom lens.

  Conventionally, as a large-diameter telephoto zoom lens of F2.8 class, for example, a zoom lens as disclosed in Patent Document 1 or Patent Document 2 has been proposed.

  Patent Document 1 discloses a four-group zoom lens in which the refractive power of each lens group is positive, negative, positive, and positive from the object side. In this type of zoom lens, zooming is performed by moving the second lens group having a negative refractive power and the third lens group having a positive refractive power. The first lens unit having positive refractive power is divided into a front group and a rear group, and focusing is performed by moving the rear group. With this configuration, a telephoto zoom lens for an interchangeable lens having a zoom ratio of 3 times is obtained.

  Patent Document 2 discloses a 5-group zoom lens in which the refractive power of each lens group is positive, negative, positive, negative, and positive from the object side. In this type of zoom lens, zooming is performed by moving a second lens group having a negative refractive power, a third lens group having a positive refractive power, and a fourth lens group having a negative refractive power. Then, focusing is performed by moving the third lens unit having positive refractive power. With this configuration, a telephoto zoom lens for an interchangeable lens having a zoom ratio of 3 times is obtained.

  On the other hand, in recent years, there is an increasing need for not only still images but also moving image shooting, and a lens system that is optimized for moving image shooting functions is also required for lens-integrated cameras and interchangeable lens digital cameras.

  Generally, in moving image shooting, it is necessary to keep an in-focus state by always operating an autofocus function. As one of the methods, there is known a system in which the focusing lens group is always moved by a minute amount before and after the in-focus position (called wobbling). When the change in contrast of the image on the imaging surface is measured by wobbling and it is determined that the in-focus state has changed, the focusing lens group is appropriately moved so as to re-focus. With such a wobbling function, even if the distance between the zoom lens and the subject changes, the in-focus state is always maintained, but a very high-speed operation is required according to the frame rate of the camera body. In order to perform appropriate drive control, the focusing lens group is required to be light in weight and move little. In addition, a reduction in sound accompanying wobbling is also required for reducing noise during moving image shooting. Normally, the focusing lens group and the wobbling lens group are often the same, but they may be configured as separate lens groups.

  There is also known a method of performing focusing by detecting a phase difference of a subject image on the imaging surface from light rays that have passed through different pupil positions and calculating a subject distance.

JP 2007-212830 A JP 2010-191336 A

  In zoom lenses, optimization such as securing a zoom ratio, ensuring brightness, and miniaturization is required. The present invention has been made in view of the above-mentioned problems, and provides a zoom lens that is advantageous for ensuring both a zoom ratio and a brightness.

The zoom lens according to the first aspect of the present invention for solving the above-mentioned problem is, in order from the object side to the image side, in order, substantially a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having positive refractive power, a fourth lens unit having a negative refractive power, a fifth lens group composed of one negative lens, the sixth lens unit having a positive refractive power and a first lens group and the second lens The distance between the second lens group and the third lens group is wider at the telephoto end than at the wide-angle end, and the distance between the second lens group and the third lens group is narrower at the telephoto end than at the wide-angle end. The distance between the lens group changes during zooming from the wide-angle end to the telephoto end, and the distance between the fourth lens group and the fifth lens group varies during zooming from the wide-angle end to the telephoto end. The distance between the fifth lens group and the sixth lens group changes during zooming from the wide-angle end to the telephoto end, and the first lens group and the third lens The distance between the groups, Ri Semama at the telephoto end than at the wide angle end is characterized that you satisfy the following condition (6-1).
0 <(r51−r52) / (r51 + r52) <4 (6-1)
However,
r51 is a paraxial radius of curvature of the object side surface of the negative lens in the fifth lens group,
r52 is a paraxial radius of curvature of the image side surface of the negative lens in the fifth lens group,
It is.

The zoom lens according to the second aspect of the present invention for solving the above-described problem is, in order from the object side to the image side, substantially, a first lens group having a positive refractive power, a second lens group having a negative refractive power, The third lens group having positive refracting power, the fourth lens group having negative refracting power, the fifth lens group comprising one negative lens, and the sixth lens group having positive refracting power, the first lens group having a wide angle end The position of the second lens group, the third lens group, the fourth lens group, and the fifth lens group move during zooming from the wide-angle end to the telephoto end, and the first lens group The distance between the second lens group and the second lens group is wider at the telephoto end than at the wide-angle end, and the distance between the second lens group and the third lens group is narrower at the telephoto end than at the wide-angle end. The distance between the first lens group and the fourth lens group changes during zooming from the wide-angle end to the telephoto end, and the fourth lens group and the fifth lens group. The distance between changes during zooming to the telephoto end from the wide-angle end, the distance between the fifth lens group and the sixth lens group changes upon zooming to the telephoto end from the wide angle end The following conditional expression (6-1) is satisfied .
0 <(r51−r52) / (r51 + r52) <4 (6-1)
However,
r51 is a paraxial radius of curvature of the object side surface of the negative lens in the fifth lens group,
r52 is a paraxial radius of curvature of the image side surface of the negative lens in the fifth lens group,
It is.
The zoom lens according to the third aspect of the present invention includes, in order from the object side to the image side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens having a positive refractive power. A fourth lens group having a negative refractive power, a fifth lens group including one positive lens, and a sixth lens group having a positive refractive power, and the distance between the first lens group and the second lens group is The distance between the second lens group and the third lens group is narrower at the telephoto end than at the wide-angle end, and the distance between the third lens group and the fourth lens group is wider at the telephoto end than at the wide-angle end. The distance changes during zooming from the wide-angle end to the telephoto end, and the distance between the fourth lens group and the fifth lens group changes during zooming from the wide-angle end to the telephoto end. The distance between the first lens group and the sixth lens group changes during zooming from the wide-angle end to the telephoto end, and the distance between the first lens group and the third lens group varies at the wide-angle end. Narrowing at remote telephoto end, and characterized by satisfying the following conditional expression (6-2).
-1 <(r51-r52) / (r51 + r52) <0 (6-2)
However,
r51 is a paraxial radius of curvature of the object side surface of the positive lens in the fifth lens group,
r52 is a paraxial radius of curvature of the image side surface of the positive lens in the fifth lens group,
It is.
The zoom lens according to the fourth aspect of the present invention includes, in order from the object side to the image side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens having a positive refractive power. Group, a fourth lens group having negative refracting power, a fifth lens group comprising one positive lens, and a sixth lens group having positive refracting power. The first lens group has a zoom ratio from the wide angle end to the telephoto end. Sometimes the position is stationary, and the second lens group, the third lens group, the fourth lens group, and the fifth lens group move during zooming from the wide-angle end to the telephoto end, and the first lens group and the second lens group The distance between the second lens group and the third lens group is wider at the telephoto end than at the wide-angle end, and the distance between the second lens group and the third lens group is narrower at the telephoto end than at the wide-angle end. The distance between the fourth lens group and the fifth lens group changes during zooming from the wide-angle end to the telephoto end. The distance between the fifth lens group and the sixth lens group changes during zooming from the wide-angle end to the telephoto end, and the following conditional expression (6- It is characterized by satisfying 2).
-1 <(r51-r52) / (r51 + r52) <0 (6-2)
However,
r51 is a paraxial radius of curvature of the object side surface of the positive lens in the fifth lens group,
r52 is a paraxial radius of curvature of the image side surface of the positive lens in the fifth lens group,
It is.

  According to the present invention, it is possible to provide a zoom lens that is advantageous for improving the performance of a zoom lens including six lens groups.

1 is a cross-sectional view of a lens at a wide-angle end, an intermediate focal length state, and a telephoto end, and a wide-angle end, an intermediate focal length state, an intermediate focal length state, and a telephoto end when focusing on an object point at infinity according to Embodiment 1 of the zoom lens of the present invention. It is a figure showing the focusing system in the displacement direction of each lens group of an end, a wide angle end, an intermediate focal length state, and a telephoto end. It is the same figure as FIG. 1 of Example 2 of the zoom lens of this invention. It is the same figure as FIG. 1 of Example 3 of the zoom lens of this invention. It is the same figure as FIG. 1 of Example 4 of the zoom lens of this invention. It is the same figure as FIG. 1 of Example 5 of the zoom lens of this invention. It is the same figure as FIG. 1 of Example 6 of the zoom lens of this invention. It is the same figure as FIG. 1 of Example 7 of the zoom lens of this invention. FIG. 6 is an aberration diagram for Example 1 upon focusing on an infinite distance. FIG. 6 is an aberration diagram for focusing on a close range where the distance between object images of Example 1 is 0.7 m. FIG. 6 is an aberration diagram for Example 2 upon focusing on an infinite distance. FIG. 10 is an aberration diagram for focusing on a close range where the distance between object images of Example 2 is 0.7 m. FIG. 10 is an aberration diagram for Example 3 upon focusing on an infinite distance. FIG. 12 is an aberration diagram for focusing on a close range where the distance between object images of Example 3 is 0.7 m. FIG. 10 is an aberration diagram for Example 4 upon focusing on an infinite distance. FIG. 12 is an aberration diagram for Example 4 when focusing on a close distance where the distance between object images is 0.7 m. FIG. 10 is an aberration diagram for Example 5 upon focusing on an infinite distance. FIG. 10 is an aberration diagram for Example 5 when focusing on a very close distance at which the distance between object images is 0.7 m. FIG. 10 is an aberration diagram for Example 6 upon focusing on an infinite distance. FIG. 10 is an aberration diagram for Example 6 when focusing on a close range where the distance between object images is 0.7 m. FIG. 10 is an aberration diagram for Example 7 upon focusing on an infinite distance. FIG. 12 is an aberration diagram for focusing on a close range where the distance between object images of Example 7 is 0.7 m. It is sectional drawing of the imaging device which used the zoom lens of one Embodiment as an interchangeable lens. It is a front perspective view which shows the external appearance of the digital camera of one Embodiment. It is a back perspective view showing the appearance of the digital camera of one embodiment. It is a front perspective view which shows the external appearance of the digital camera of other embodiment. It is a rear view which shows the external appearance of the digital camera of other embodiment. It is a typical cross-sectional view which shows the structure of the digital camera of other embodiment. It is a block diagram which shows the control structure of the digital camera of this embodiment.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

  FIGS. 1 to 7 are cross-sectional views taken along the optical axis of the zoom lenses of Examples 1 to 7 of the present invention. In each figure, (a) shows the wide-angle end (WE), (b) shows the intermediate focal length state (ST), and (c) shows the telephoto end (TE).

  The zoom lens according to the embodiment of the present invention includes, in order from the object side to the image 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, and a negative refraction. It has a fourth lens group G4 having power, a fifth lens group G5 including lenses, and a sixth lens group G6 having positive refractive power.

  The distance between the first lens group G1 and the second lens group G2 is wider at the telephoto end than at the wide angle end, and the distance between the second lens group G2 and the third lens group G3 is at the wide angle end. The distance between the third lens group G3 and the fourth lens group G4 changes at the time of zooming from the wide-angle end to the telephoto end, and the fourth lens group G4 and the fifth lens group. The distance to G5 changes during zooming from the wide-angle end to the telephoto end, and the distance between the fifth lens group G5 and the sixth lens group G6 is zooming from the wide-angle end to the telephoto end. Change when.

  In this way, the first lens group having positive refractive power, the second lens group having negative refractive power, the third lens group having positive refractive power, and the fourth lens group having negative refractive power are arranged, and the mutual distance is changed. Therefore, the overall length is shortened and the zoom ratio is secured.

  The sixth lens group G6 has a positive refractive power and has an effect of separating the exit pupil from the image plane. Shading is reduced by the oblique incidence characteristics of the image sensor.

  The fifth lens group G5 is disposed between the fourth lens group G4 and the sixth lens group G6. The fifth lens group G5 suppresses aberration fluctuations associated with zooming.

  With this configuration, in the embodiment, the distance between the first lens group G1 and the third lens group G3 is narrower at the telephoto end than at the wide angle end.

  The distance between the first lens group and the third lens group is smaller at the telephoto end than at the wide-angle end, so that the entrance pupil position is not too far from the first lens group at the telephoto end. . Therefore, it is possible to secure the entrance pupil diameter at the telephoto end while reducing the effective diameter of the first lens group.

  In the embodiment, the first lens group G1 is stationary at the time of zooming from the wide angle end to the telephoto end.

  This is advantageous for reducing dust intrusion into the lens system, suppressing sound leakage when moving the lens group, and reducing fluctuations in weight balance due to zooming of the lens system.

The fourth lens group G4 and the fifth lens group G5 move during zooming from the wide angle end to the telephoto end.
This is advantageous in achieving both reduction of aberration and securing of a zoom ratio.

  Furthermore, the second lens group G2 and the third lens group G3 move during zooming from the wide-angle end to the telephoto end.

  The second lens group, the third lens group, the fourth lens group, and the fifth lens group move during zooming from the wide-angle end to the telephoto end, thereby performing zooming with reduced aberration.

Regarding the movement of the third lens group G3, the third lens group G3 satisfies the following conditional expression (1).
0.2 <ΔG3 / f3 <1 (1)
However,
ΔG3 is a displacement amount of the position of the third lens group at the telephoto end with respect to the wide-angle end, and the displacement toward the object side is positive,
f3 is the focal length of the third lens group,
It is.

   The amount of movement of the third lens group is suppressed so as not to exceed the upper limit, and the increase in the total lens length is suppressed. In addition, the refractive power of the third lens group is suppressed, which leads to a reduction in aberrations and a reduction in the number of lenses.

  The first lens group is reduced in size in the radial direction so as not to fall below the lower limit.

  The zoom lens has an aperture stop S that is disposed between the second lens group G2 and the fourth lens group G4 and moves toward the object side at the telephoto end with respect to the wide angle end. More specifically, the aperture stop S is disposed between the second lens group G2 and the third lens group G3.

  With this configuration, both the reduction of the diameter of the entire zoom lens system and the reduction of aberration are achieved.

  The aperture stop S is configured such that the aperture size at the minimum F number is larger at the telephoto end than at the wide angle end.

Near the wide-angle end, the difference in the amount of light between the center of the image plane and the periphery of the image plane due to vignetting can be suppressed, and both an improvement in image quality and a reduction in diameter near the wide-angle end are achieved.

The fourth lens group G4 and the fifth lens group G5 are moved during the focusing operation.

  The fourth lens group is a lens group that tends to reduce the radial direction. The fifth lens group is a lens group that can be easily reduced in weight. By making these lens groups into focusing lens groups, the driving burden (power burden, etc.) during focusing is reduced. Here, since a plurality of lens groups are lens groups that move during focusing, it is possible to reduce aberrations and shorten the shortest shooting distance at the time of focusing both at a long distance and at a close distance.

  In Examples 1 to 5 and 7, in which the fifth lens group G5 has a negative refractive power, the moving direction during focusing to a short distance at the wide angle end and the moving direction during focusing to a short distance at the telephoto end are the first. The fourth lens group G4 is different from the fifth lens group G5.

  With this configuration, aberrations are suppressed both when focusing at infinity and when focusing close to the object.

  In the zoom lenses of Examples 1 to 5 and 7, the fifth lens group G5 has a negative refractive power.

  In the zoom lens of Embodiment 6, the fifth lens group G5 has a positive refractive power.

In either case, by changing the air space before and after the fourth lens group, both the securing of the zoom ratio and the reduction of aberrations are achieved.

The sixth lens group G6 is stationary at the time of zooming from the wide-angle end to the telephoto end.

With this configuration, dust intrusion into the zoom lens system is reduced and sound leakage during lens driving is reduced.

The second lens group G2 has three cemented lens components of a positive lens, a negative lens, and a positive lens in order from the object side to the image side.

  Here, the lens component is a lens block in which there are only two refracting surfaces in contact with air in the optical path, the object side surface and the image side surface.

  It is easy to suppress the occurrence of distortion and astigmatism at the wide-angle end, spherical aberration and coma at the telephoto end, and chromatic aberration of magnification, so that the zooming function of the second lens group is sufficiently secured.

  In particular, the negative lens in the three-piece cemented lens component satisfies the following conditional expression (2).

1 <(r21−r22) / (r21 + r22) <5 (2)
However,
r21 is the paraxial radius of curvature of the object side surface of the negative lens in the triplet cemented lens component,
r22 is the paraxial radius of curvature of the image side surface of the negative lens in the triplet cemented lens component,
It is.

  In the embodiment, by satisfying conditional expression (2), the aberration can be reduced more easily.

  The third lens group G3 that receives the axial light beam that diverges from the second lens group G2 is likely to have a large radial direction. In the case of the bright zoom lens as in the embodiment, the axial light beam diameter is particularly large in the third lens group G3. The third lens group G3 includes a negative lens and a plurality of positive lenses, and corrects spherical aberration that occurs on the telephoto side.

  Furthermore, the following conditional expressions (3) and (4) are satisfied.

75 <νd3p <100 (3)
1.4 <f31p / f3 <3.7 (4)
However,
νd3p is the maximum value among the Abbe numbers on the d-line basis of all the positive lenses in the third lens group,
f31p is the focal length of the positive lens closest to the object side in the third lens group,
f3 is the focal length of the third lens group,
It is.

  Since the zoom lens of the embodiment maintains a bright F number even at the telephoto end, correction of chromatic aberration is very important. In particular, high performance is achieved by improving the correction of axial chromatic aberration on the telephoto side.

On-axis chromatic aberration correction is performed so as not to fall below the lower limit of conditional expression (3).
The material cost is reduced by not exceeding the upper limit.

  Keeping the lower limit of conditional expression (4) below, moderately reducing the refractive power of the positive lens to suppress aberrations, and not exceeding the upper limit to ensure sufficient convergence of the positive lens closest to the object side, The subsequent lens is downsized.

  Further, the most object side lens in the third lens group G3 is a positive lens, a negative lens is disposed on the image side, and a positive lens is disposed on the image side. More specifically, the third lens group G3 includes five lenses in order from the object side: a positive lens, a positive lens, a negative lens, a positive lens, and a positive lens.

  This is advantageous for downsizing the third lens group in the radial direction and reducing aberrations such as spherical aberration, coma, and astigmatism.

  The fourth lens group G4 is composed of one negative lens, and reduces the weight of the fourth lens group. In the embodiment, since the fourth lens group G4 is a focusing lens group, the burden on the focusing drive mechanism is reduced.

  The fourth lens group G4 is a wobbling lens group. The weight of the wobbling lens group is being reduced at the same time.

  The fourth lens group G4 satisfies the following conditional expression (5).

0.6 <(r41−r42) / (r41 + r42) <2 (5)
However,
r41 is a paraxial radius of curvature of the object side surface of the negative lens in the fourth lens group,
r42 is the paraxial radius of curvature of the image side surface of the negative lens in the fourth lens group,
It is.

  When the fourth lens group satisfies the conditional expression (5), spherical aberration is reduced at the telephoto end. Variations in spherical aberration of the fourth lens group due to focusing are also suppressed.

The fifth lens group G5 includes one lens, and the fifth lens group is reduced in weight. In the embodiment, since the fifth lens group is a focusing lens group, the burden on the focusing drive mechanism is reduced.
The fifth lens group G5 satisfies the following conditional expression (6).

-1 <(r51-r52) / (r51 + r52) <4 (6)
However,
r51 is the paraxial radius of curvature of the object side surface of the lens in the fifth lens group,
r52 is a paraxial radius of curvature of the image side surface of the lens in the fifth lens group,
It is.

  The distortion aberration at the wide-angle end and the lateral chromatic aberration at the telephoto end are reduced.

  In the zoom lenses of Examples 1 to 5 and 7, the fifth lens group G5 is composed of one negative lens.

  And the following conditional expression (6-1) is satisfied.

0 <(r51−r52) / (r51 + r52) <4 (6-1)
The distortion aberration at the wide-angle end and the lateral chromatic aberration at the telephoto end are reduced.

In Example 6, the fifth lens group G5 is composed of one positive lens.
And the following conditional expression (6-2) is satisfied.

-1 <(r51-r52) / (r51 + r52) <0 (6-2)
The distortion aberration at the wide-angle end and the lateral chromatic aberration at the telephoto end are reduced.

  At the telephoto end, the fourth lens group G4 and the fifth lens group G5 move while satisfying the following conditional expression (7) during focusing from the infinite focus state to the close focus state.

0.2 <| ΔG5 (T) / ΔG4 (T) | <2 (7)
However,
ΔG4 (T) is the amount of movement of the fourth lens group at the telephoto end during focusing from the infinitely focused state to the closest focused state,
ΔG5 (T) is the amount of movement of the fifth lens group at the telephoto end during focusing from the infinitely focused state to the closest focused state,
It is.

  The amount of movement of the fifth lens group is secured so as not to fall below the lower limit, and the effect of aberration correction is sufficiently secured.

  In order not to exceed the upper limit, the amount of movement of the fifth lens unit is moderately suppressed, and the lateral chromatic aberration at the telephoto end is reduced.

  The following conditional expressions (8) and (9) are satisfied.

3.2 <ft / fw <6 (8)
1.4 <FNO (T) <3.0 (9)
However,
ft is the focal length at the telephoto end of the zoom lens,
fw is the focal length at the wide angle end of the zoom lens,
FNO (T) is an F number at the telephoto end of the zoom lens.

  While making it easy to change the angle of view as a zoom ratio that does not fall below the lower limit of conditional expression (8), the zoom lens can be made more compact so as not to exceed the upper limit.

  The brightness at the telephoto end is ensured so as not to exceed the upper limit while reducing the lens radial direction so as not to fall below the lower limit of conditional expression (9).

  Examples will be described later, but any one of the zoom lenses described above and an image pickup device that is disposed on the image side thereof and has an image pickup surface for picking up an image formed by the zoom lens, and converts the image into an electric signal. It can be used as an imaging device having

  It is more preferable that the above-described configurations and conditional expressions satisfy a plurality of them simultaneously.

  When the zoom lens includes a focusing mechanism, the above-described configurations and conditional expressions are configured in a state where the zoom lens is focused on the farthest distance.

  In addition, if the following conditional expressions are further set as follows, the effect can be ensured.

Regarding conditional expression (1), it is more preferable to set the lower limit value to 0.3, and further to 0.35.
More preferably, the upper limit value is 0.65, more preferably 0.61.

For conditional expression (2), it is more preferable to set the lower limit value to 2, further 2.5.
Set the upper limit to 4 . More preferably, it is set to 5.

For conditional expression (3), it is more preferable to set the lower limit value to 80.
More preferably, the upper limit value is 96.

For conditional expression (4), it is more preferable to set the lower limit to 1.8.
More preferably, the upper limit is 2.7.

For conditional expression (5), it is more preferable to set the lower limit value to 1, more preferably 1.1.
More preferably, the upper limit is 1.8, and more preferably 1.6.

For conditional expression (6-1), it is more preferable to let the lower limit value to be 0.2.
More preferably, the upper limit value is 3.

Regarding conditional expression (6-2), it is more preferable to let the lower limit value to be −0.5.
More preferably, the upper limit value is -0.1.

For conditional expression (7), it is more preferable to set the lower limit value to 0.4, more preferably 0.45.
More preferably, the upper limit value is 1.6, more preferably 1.5.

For conditional expression (8), it is more preferable to set the lower limit value to 3.4.
More preferably, the upper limit value is 5.

For conditional expression (9), it is more preferable to let the lower limit value to be 2.0.
More preferably, the upper limit value is 3.0.

  The zoom lenses according to the first to seventh embodiments of the present invention will be described with reference to the drawings.

  In any of the first to seventh embodiments, in order from the object side, the first lens group G1 having a positive refractive power, the second lens group G2 having a negative refractive power, the third lens group G3 having a positive refractive power, and a negative refractive power. 4th lens group G4, 5th lens group G5 which has a lens, and 6th lens group G6 of positive refractive power. During zooming from the wide-angle end to the telephoto end, the first lens group is fixed, the second lens group moves only to the image side, the third lens group moves only to the object side, and the fourth lens group moves to the object side. The fifth lens group reciprocates along the optical axis, and the sixth lens group is fixed with respect to the image plane.

  The aperture stop S is disposed immediately before the object side of the third lens group G3, and moves together with the third lens group.

  The maximum diameter of the aperture of the aperture stop S increases from the wide-angle end to the telephoto end, and the F-number is almost constant (2.88) regardless of the focal length in the infinite focus state. Yes.

  On the image side of the zoom lens, a parallel plate C that represents a filter or a cover glass of the image sensor as an optically equivalent member and an image pickup surface I of the image sensor are located.

  The fifth lens group G5 of Examples 1 to 5 and 7 has a negative refractive power, and when moving from the wide angle end to the telephoto end, it first moves to the object side and then moves to the image side. At the time of focusing from a long distance to a short distance, the fourth lens group G4 and the fifth lens group G5 move independently to the image side at the wide angle end. At the telephoto end, the fourth lens group G4 moves to the image side, and the fifth lens group G5 moves to the object side. The fourth lens group G4 also performs a wobbling operation.

  The fifth lens group G5 of Example 6 has a positive refractive power, and first moves to the image side and then moves to the object side upon zooming from the wide-angle end to the telephoto end. During focusing from a long distance to a short distance, the fourth lens group G4 and the fifth lens group G5 independently move toward the image side from the wide-angle end to the telephoto end. The fourth lens group G4 also performs a wobbling operation.

  Each of the embodiments is a telephoto zoom lens having a large aperture and high performance that is optimal for use as an interchangeable lens system.

  FIG. 1 is a cross-sectional view of the zoom lens according to the first exemplary embodiment.

  The first lens group G1 includes four lenses, a positive lens L11, a positive lens L12, a negative lens L13, and a positive lens L14.

  The second lens group G2 is composed of four lenses including a cemented lens component including a positive lens L21, a negative lens L22, and a positive lens L23, and a negative lens L24.

  The third lens group G3 includes five lenses: a double-sided aspherical positive lens L31, a positive lens L32, a negative lens L33, a positive lens L34, and a double-sided aspherical positive lens L35.

  The fourth lens group G4 includes one negative lens L41 having an aspheric image side surface.

  The fifth lens group G5 is composed of one negative lens L51.

  The sixth lens group G6 is composed of a single positive lens L61.

  FIG. 2 is a cross-sectional view of the zoom lens according to the second embodiment.

  The first lens group G1, the second lens group G2, and the sixth lens group G6 are the same as those in the first embodiment.

  The third lens group G3 is composed of five lenses: a positive lens L31, a positive lens L32, a negative lens L33, a positive lens L34, and a double-sided aspheric positive lens L35.

  The fourth lens group G4 includes one negative aspherical lens L41.

  The fifth lens group G5 includes one negative aspherical lens L51.

  FIG. 3 is a sectional view of the zoom lens according to the third embodiment.

  The second lens group G2 and the sixth lens group G6 are the same as those described in the first embodiment, and the third lens group G3, the fourth lens group G4, and the fifth lens group G5 are the same as those described in the second embodiment.

  The first lens group G1 includes three lenses, that is, a positive lens L11, a negative lens L12, and a positive lens L13.

  FIG. 4 is a cross-sectional view of the zoom lens of Example 4.

  The second lens group G2, the fifth lens group G5, and the sixth lens group G6 are described in Example 1, the fourth lens group G4 is described in Example 2, and the first lens group G1 is described in Example 3. It is the same as the explanation of.

  The third lens group includes a positive lens L31, a cemented negative lens component of the positive lens L32 and the negative lens L33, a positive lens L34, and a double-sided aspheric positive lens L35.

  FIG. 5 is a cross-sectional view of the zoom lens of Example 5.

  The second lens group G2, the fourth lens group G4, and the sixth lens group G6 are described in Example 1, the fifth lens group G5 is described in Example 2, and the third lens group G3 is described in Example 4. It is the same as the explanation of.

  The first lens group G1 includes three lenses, that is, a cemented positive lens component of a negative lens L11 and a positive lens L12, and a positive lens L13.

  FIG. 6 is a cross-sectional view of the zoom lens according to the sixth embodiment.

  The second lens group G2 and the fourth lens group G4 are the same as in the description of Example 1, and the third lens group G3 is the same as in the description of Example 2.

  The first lens group G1 includes three lenses, that is, a negative lens L11, a positive lens L12, and a positive lens L13.

  The fifth lens group G5 is composed of one positive lens L51.

  The sixth lens group G6 includes a single positive lens L61 having an aspheric image side surface.

  FIG. 7 is a sectional view of the zoom lens according to the seventh embodiment.

    The second lens group G2 and the fifth lens group G5 are described in the first embodiment, the fourth lens group G4 is described in the second embodiment, and the first lens group G1 is described in the third embodiment. The lens group G6 is the same as that described in the fifth embodiment.

  The third lens group G3 is composed of five lenses: a positive lens L31, a three-piece negative lens component of a positive lens L32, a negative lens L33, and a positive lens L34, and a double-sided aspheric positive lens L35.

  In any of the embodiments, since the first lens group G1 and the sixth lens group G6 are fixed with respect to the image plane, the lens barrel structure can be simplified. In addition, the center of gravity at the time of zooming from the wide-angle end (WE) to the telephoto end (TE) is small and stable holding is possible. Further, it is advantageous for reducing sound generated during zooming or focusing from the wide-angle end (WE) to the telephoto end (TE).

  Various numerical data of Examples 1 to 7 are shown below.

  The surface data includes, for each surface number, the radius of curvature r of each lens surface (optical surface), the surface interval d, the refractive index nd of each lens (optical medium) with respect to the d-line (587.6 nm), and each lens (optical medium). The Abbe number νd of the d line is shown. The unit of the radius of curvature r and the surface interval d is millimeters (mm). In the surface data, “∞” described in the radius of curvature indicates infinite.

  Surfaces marked with * in the surface number are aspherical. The aspheric coefficient indicates data related to a lens surface having an aspheric shape in the surface data. The aspherical shape is expressed by the following equation, where x is an optical axis with the light traveling direction being positive, and y is a direction orthogonal to the optical axis.

z = (y ² / r) / [1+ {1− (1 + K) · (y / r) ² } ^1/2 ]
^{+ A4y 4 + A6y 6 + A8y} 8 + A10y 10 ...
Here, r is a paraxial radius of curvature, K is a conical coefficient, and A4, A6, A8, and A10 are fourth-order, sixth-order, eighth-order, and tenth-order aspheric coefficients, respectively. The symbol “E” indicates that the subsequent numerical value is a power exponent with 10 as the base. For example, “1.0E-5” means “1.0 × 10 ⁻⁵ ”.

  In the zoom data, a focal length, an F number (Fno), an angle of view 2ω (°), a variable surface distance D, an air-converted back focus (BF), a total lens length, and an image height are shown. The unit is millimeters (mm), except for the F number and the angle of view.

  Further, WE indicates a wide angle end, ST indicates an intermediate focal length state, and TE indicates a telephoto end.

  Each group focal length data indicates focal lengths f1 to f6 in each lens group. All units are millimeters (mm).

Numerical example 1
Surface data surface number r d nd νd
1 161.8625 4.385 1.48749 70.23
2 -939.1645 0.150
3 73.7720 5.204 1.49700 81.54
4 252.3629 0.150
5 76.4145 2.500 1.80000 29.84
6 47.9471 1.555
7 49.2297 6.796 1.49700 81.54
8 315.6860 D8 (variable)
9 208.6397 5.191 1.91082 35.25
10 -42.8331 1.600 1.69700 48.52
11 25.0886 2.709 1.92286 18.90
12 32.7854 4.591
13 -36.2846 1.500 1.83481 42.71
14 135.2384 D14 (variable)
15 Brightness stop ∞ 1.250
16 * 29.9169 4.096 1.74320 49.29
17 * -9370.4409 3.777
18 39.8922 5.573 1.43875 94.93
19 -32.6290 0.150
20 84.7715 1.400 1.90366 31.32
21 18.6481 3.264
22 48.7115 3.498 1.49700 81.54
23 -63.3717 0.150
24 * 24.4196 3.565 1.58313 59.38
25 * 536.4898 D25 (variable)
26 -128.6809 1.200 1.74320 49.29
27 * 16.0684 D27 (variable)
28 -137.3219 1.200 1.48749 70.23
29 63.8881 D29 (variable)
30 56.6262 4.565 1.76200 40.10
31 -41.8597 25.763
32 ∞ 4.000 1.51633 64.14
33 ∞ 0.800
Image plane (imaging plane)
Aspheric coefficient 16th surface
K = 0, A4 = 9.1265E-06, A6 = 4.0231E−08, A8 = 1.1599E-10, A10 = 0.0000E + 00
17th page
K = 0, A4 = 3.2233E-05, A6 = 5.2116E-08, A8 = 1.5473E-10, A10 = 0.0000E + 00
24th page
K = 0, A4 = 6.4394E-06, A6 = 1.5321E-08, A8 = 0.0000E + 00, A10 = 0.0000E + 00
25th page
K = 0, A4 = -1.0054E-05, A6 = -3.1844E-09, A8 = 0.0000E + 00, A10 = 0.0000E + 00
27th page
K = -0.8643, A4 = 8.3394E-06, A6 = -5.1963E-09, A8 = 0.0000E + 00, A10 = 0.0000E + 00
Zoom data
WE ST TE
Focal length 40.80 77.50 147.00
Fno 2.88 2.88 2.88
Angle of view (2ω) 29.55 ° 15.53 ° 8.24 °
Image height 10.82 10.82 10.82
BF 29.20 29.20 29.20 Total length in air 151.88 151.88 151.88 〃
Group spacing (infinite)
WE ST TE
D 8 1.000 17.531 30.023
D14 39.858 19.827 1.716
D25 2.500 3.760 2.667
D27 6.127 6.403 16.258
D29 3.179 5.143 2.000
Group spacing (distance between objects 0.7m)
WE ST TE
D 0 546.080 546.080 546.080
D 8 1.000 17.531 30.023
D14 39.858 19.827 1.716
D25 3.072 5.863 9.475
D27 6.734 3.868 3.321
D29 2.000 5.575 8.129
Each group focal length f1 92.809
f2 -26.387
f3 23.823
f4 -19.153
f5 -89.268
f6 32.231

Numerical example 2
Surface data surface number r d nd νd
1 224.1379 4.079 1.48749 70.23
2 -385.1974 0.150
3 57.8744 5.093 1.49700 81.54
4 133.2050 0.150
5 67.9609 2.500 1.90366 31.32
6 44.2704 1.949
7 45.7334 6.628 1.49700 81.54
8 263.9719 D8 (variable)
9 128.2550 5.588 1.91082 35.25
10 -47.3000 1.600 1.69700 48.52
11 23.9824 2.664 1.92286 18.90
12 30.5465 5.390
13 -36.0447 1.500 1.83481 42.71
14 119.3580 D14 (variable)
15 Brightness stop ∞ 1.250
16 26.4663 3.984 1.77250 49.60
17 85.0893 2.668
18 22.5884 5.730 1.43875 94.93
19 -213.4986 0.538
20 1058.5517 1.400 1.90366 31.32
21 23.7500 3.082
22 18.1277 4.245 1.49700 81.54
23 43.4126 0.150
24 * 18.1696 3.319 1.58313 59.38
25 * -1988.2486 D25 (variable)
26 * -178.1930 1.200 1.74320 49.29
27 * 15.3626 D27 (variable)
28 * 217.1212 1.200 1.58313 59.38
29 * 37.0521 D29 (variable)
30 43.3556 4.912 1.80610 40.88
31 -51.7168 25.308
32 ∞ 4.000 1.51633 64.14
33 ∞ 0.800
Image plane (imaging plane)
Aspheric coefficient 24th surface
K = -0.1539, A4 = -1.7974E-05, A6 = 9.7260E-08, A8 = -5.2928E-10, A10 = 8.7249E-12
25th page
K = 0, A4 = 4.5095E-05, A6 = 3.7225E-08, A8 = 8.2034E-10, A10 = 2.7708E-12
26th page
K = 0, A4 = -1.1341E-05, A6 = -6.1677E-08, A8 = 3.5886E-09, A10 = -2.9499E-11
27th page
K = -1.0873, A4 = 3.0008E-06, A6 = 7.9340E-08, A8 = 8.4760E-10, A10 = -1.0821E-11
28th page
K = 0, A4 = 1.2835E-05, A6 = -5.6280E-09, A8 = 0.0000E + 00, A10 = 0.0000E + 00
29th page
K = 1.5494, A4 = 4.4391E-06, A6 = -1.9963E-08, A8 = 0.0000E + 00, A10 = 0.0000E + 00
Zoom data
WE ST TE
Focal length 40.80 77.96 147.00
Fno 2.88 2.88 2.88
Angle of view (2ω) 29.53 ° 15.53 ° 8.26 °
Image height 10.82 10.82 10.82
BF 28.75 28.75 28.75 Total length in air 151.88 151.88 151.88 〃
Group spacing (infinite)
WE ST TE
D 8 0.845 17.800 29.252
D14 40.030 19.950 1.500
D25 2.006 3.060 2.163
D27 5.835 6.396 17.752
D29 3.451 4.961 1.500
Group spacing (distance between objects 0.7m)
WE ST TE
D 0 546.700 546.700 546.700
D 8 0.845 17.800 29.252
D14 40.030 19.950 1.500
D25 2.616 5.188 8.818
D27 5.718 4.865 7.919
D29 2.958 4.364 4.678
Each group focal length f1 94.630
f2 -26.657
f3 23.388
f4 -18.980
f5 -76.804
f6 29.948

Numerical example 3
Surface data surface number r d nd νd
1 78.3067 6.287 1.48749 70.23
2 ∞ 0.150
3 58.3004 2.357 1.80518 25.42
4 41.5439 1.972
5 42.9221 7.667 1.49700 81.54
6 300.3014 D6 (variable)
7 133.8679 5.450 1.91082 35.25
8 -52.8170 1.600 1.69700 48.52
9 23.0332 2.938 1.92286 18.90
10 29.6919 6.656
11 -36.1478 1.500 1.83481 42.71
12 139.4883 D12 (variable)
13 Brightness stop ∞ 1.250
14 25.3033 3.844 1.77250 49.60
15 62.4416 3.670
16 22.6985 5.048 1.43875 94.93
17 -176.8538 0.150
18 318.8681 1.400 1.90366 31.32
19 23.7626 1.958
20 21.4425 3.394 1.49700 81.54
21 54.1793 0.150
22 * 17.0527 4.140 1.58313 59.38
23 * -1542.0344 D23 (variable)
24 * -135.3978 1.200 1.74320 49.29
25 * 15.9244 D25 (variable)
26 * 206.7566 1.200 1.58313 59.38
27 * 34.7332 D27 (variable)
28 44.1850 4.638 1.80610 40.88
29 -51.0153 28.038
30 ∞ 4.000 1.51633 64.14
31 ∞ 0.800
Image plane (imaging plane)
Aspheric coefficient 22nd surface
K = 0.1748, A4 = -1.5676E-05, A6 = 8.9000E-08, A8 = -6.2366E-10, A10 = 8.8579E-12
23rd page
K = 0, A4 = 5.1798E-05, A6 = 9.5847E-08, A8 = 2.9579E-10, A10 = 5.2940E-12
24th page
K = 0, A4 = -1.0232E-05, A6 = 2.2180E-07, A8 = -2.2239E-09, A10 = 9.2648E-12
25th page
K = -1.1692, A4 = 7.5244E-06, A6 = 3.2729E-07, A8 = -5.0891E-09, A10 = 3.2451E-11
26th page
K = 0, A4 = 2.1885E-05, A6 = -6.5454E-08, A8 = 0.0000E + 00, A10 = 0.0000E + 00
27th page
K = 2.2748, A4 = 8.2210E-06, A6 = -8.2973E-08, A8 = 0.0000E + 00, A10 = 0.0000E + 00
Zoom data
WE ST TE
Focal length 40.80 75.66 147.00
Fno 2.88 2.88 2.88
Angle of view (2ω) 29.67 ° 16.05 ° 8.26 °
Image height 10.82 10.82 10.82
BF 31.48 31.48 31.48 Total length in air 151.88 151.88 151.88 〃
Group spacing (infinite)
WE ST TE
D 6 1.070 17.004 29.366
D12 39.214 20.413 1.500
D23 2.000 2.976 2.000
D25 5.476 6.525 17.422
D27 4.028 4.870 1.500
Group spacing (distance between objects 0.7m)
WE ST TE
D 0 546.700 546.700 546.700
D 6 1.070 17.004 29.366
D12 39.214 20.413 1.500
D23 2.579 4.862 8.283
D25 5.333 5.334 7.903
D27 3.592 4.175 4.736
Each group focal length f1 92.7530
f2 -26.2412
f3 22.7291
f4 -19.1074
f5 -71.7747
f6 30.0259

Numerical example 4
Surface data surface number r d nd νd
1 69.3745 6.700 1.48749 70.23
2 785.6394 0.150
3 48.6755 2.300 1.90366 31.32
4 34.6475 1.860
5 34.8467 9.880 1.43875 94.93
6 1099.2010 D6 (variable)
7 127.3560 5.350 1.91082 35.25
8 -47.2895 1.600 1.73400 51.47
9 20.9985 3.050 1.92286 20.88
10 29.4558 5.310
11 -37.3953 1.500 1.83400 37.16
12 84.4109 D12 (variable)
13 Brightness stop ∞ 1.250
14 24.9309 4.500 1.74400 44.78
15 129.7204 0.150
16 21.1517 4.210 1.43875 94.93
17 58.6483 1.400 1.90366 31.32
18 16.9308 1.230
19 17.1435 4.540 1.49700 81.54
20 96.2764 0.150
21 * 22.1865 3.870 1.59201 67.02
22 * -161.5787 D22 (variable)
23 * -77.5338 1.200 1.72903 54.04
24 * 15.3397 D24 (variable)
25 138.5435 1.200 1.74077 27.79
26 59.4845 D26 (variable)
27 59.3614 5.140 1.70154 41.24
28 -36.9207 30.495
29 ∞ 4.000 1.51633 64.14
30 ∞ 0.800
Image plane (imaging plane)
Aspheric coefficient 21st surface
K = 1.2214, A4 = -3.5419E-05, A6 = -5.2461E-08, A8 = -6.2408E-10, A10 = 6.4572E-12
22nd page
K = 0, A4 = 2.0286E-05, A6 = 5.8252E-08, A8 = -3.9011E-10, A10 = 8.5884E-12
23rd page
K = 0, A4 = -2.7251E-05, A6 = 8.4374E-07, A8 = -1.2333E-08, A10 = 6.9429E-11
24th page
K = -1.5489, A4 = -1.2515E-06, A6 = 8.8028E-07, A8 = -1.5441E-08, A10 = 1.0150E-10
Zoom data
WE ST TE
Focal length 40.80 76.12 147.00
Fno 2.88 2.88 2.88
Angle of view (2ω) 29.67 ° 15.90 ° 8.27 °
Image height 10.82 10.82 10.82
BF 33.93 33.93 33.93 Total length in air 151.88 151.88 151.88 〃
Group spacing (infinite)
WE ST TE
D 6 0.800 15.955 26.474
D12 38.742 21.234 2.214
D22 2.000 3.098 3.063
D24 5.824 4.714 18.159
D26 4.044 6.409 1.500
Group spacing (distance between objects 0.7m)
WE ST TE
D 0 546.700 546.700 546.700
D 6 0.800 15.955 26.474
D12 38.742 21.234 2.214
D22 2.530 4.909 9.527
D24 6.391 3.344 5.111
D26 2.947 5.968 8.084
Each group focal length f1 87.7817
f2 -23.7840
f3 21.2976
f4 -17.4707
f5 -141.6348
f6 33.1775

Numerical example 5
Surface data surface number r d nd νd
1 101.0042 3.000 2.00069 25.46
2 70.9827 7.100 1.49700 81.54
3 -380.7077 0.150
4 57.8570 6.400 1.49700 81.54
5 430.3072 D5 (variable)
6 195.2492 4.600 2.00100 29.13
7 -53.3154 1.600 1.70154 41.24
8 25.5454 2.700 1.92286 18.90
9 33.9351 5.370
10 -40.0762 1.500 1.80610 40.92
11 71.8286 D11 (variable)
12 Brightness stop ∞ 1.250
13 23.9404 4.940 1.73077 40.50
14 82.8711 0.580
15 23.2683 5.000 1.49700 81.54
16 152.1455 1.400 1.90366 31.32
17 17.4316 1.220
18 17.2959 5.350 1.49700 81.54
19 243.7126 0.150
20 * 21.5646 4.000 1.58313 59.38
21 * -441.2009 D21 (variable)
22 -112.2889 1.200 1.72903 54.04
23 * 17.4561 D23 (variable)
24 * 49.0253 1.200 1.63930 44.87
25 * 24.3386 D25 (variable)
26 44.0591 5.100 1.76200 40.10
27 -55.1131 31.586
28 ∞ 4.000 1.51633 64.14
29 ∞ 0.800
Image plane (imaging plane)
Aspheric coefficient 20th surface
K = 0.4266, A4 = -2.9932E-05, A6 = -1.1345E-07, A8 = -5.3515E-10, A10 = 0.0000E + 00
21st page
K = 0, A4 = 1.5155E-05, A6 = -8.0327E-08, A8 = 7.3673E-11, A10 = 0.0000E + 00
23rd page
K = -1.0346, A4 = 1.2152E-05, A6 = -2.2375E-08, A8 = -1.6219E-11, A10 = 0.0000E + 00
24th page
K = 0, A4 = -3.3317E-07, A6 = 0.0000E + 00, A8 = 0.0000E + 00, A10 = 0.0000E + 00
25th page
K = -0.9997, A4 = -2.8738E-06, A6 = 0.0000E + 00, A8 = 0.0000E + 00, A10 = 0.0000E + 00
Zoom data
WE ST TE
Focal length 40.80 75.77 147.00
Fno 2.88 2.88 2.88
Angle of view (2ω) 29.55 ° 15.99 ° 8.26 °
Image height 10.82 10.82 10.82
BF 35.02 35.02 35.02 Total length in air 151.88 151.88 151.88 〃
Group spacing (infinite)
WE ST TE
D 5 1.159 17.060 27.773
D11 42.677 22.885 2.034
D21 1.743 2.890 2.747
D23 4.860 5.078 17.645
D25 2.608 5.134 2.848
Group spacing (distance between objects 0.7m)
WE ST TE
D 0 546.700 546.700 546.700
D 5 1.159 17.060 27.773
D11 42.677 22.885 2.034
D21 2.306 4.775 9.253
D23 4.689 4.688 7.627
D25 2.216 3.639 6.360
Each group focal length f1 87.231
f2 -26.381
f3 23.304
f4 -20.642
f5 -77.066
f6 32.863

Numerical example 6
Surface data surface number r d nd νd
1 80.1028 2.300 1.90366 31.32
2 50.5589 0.770
3 50.2860 9.560 1.49700 81.54
4 -268.1012 0.150
5 50.9358 7.090 1.49700 81.54
6 435.6754 D6 (variable)
7 135.7187 4.830 1.91082 35.25
8 -44.3532 1.600 1.69680 55.53
9 22.0220 2.510 1.92286 18.90
10 27.5103 4.810
11 -33.5645 1.500 1.91082 35.25
12 96.0071 D12 (variable)
13 Brightness stop ∞ 1.250
14 25.2663 4.020 1.72000 41.98
15 63.0228 4.620
16 21.6993 5.140 1.49700 81.54
17 917.3736 0.210
18 150.9604 1.300 1.90366 31.32
19 21.4446 0.720
20 22.8790 3.300 1.49700 81.54
21 43.6271 0.770
22 * 16.1524 4.840 1.58313 59.38
23 * -150.0281 D23 (variable)
24 -89.8561 1.200 1.80610 40.92
25 * 16.2721 D25 (variable)
26 47.5311 2.070 1.92286 20.88
27 96.4449 D27 (variable)
28 198.8617 3.430 1.74320 49.34
29 * -54.0459 29.525
30 ∞ 4.000 1.51633 64.14
31 ∞ 0.800
Image plane (imaging plane)
Aspheric coefficient 22nd surface
K = 0.6222, A4 = -3.8497E-05, A6 = 1.9927E-09, A8 = -1.5528E-09, A10 = 7.7231E-12
23rd page
K = 0, A4 = 4.4637E-05, A6 = 1.4329E-07, A8 = -1.6623E-09, A10 = 1.9521E-11
25th page
K = -1.0646, A4 = 4.2772E-06, A6 = -9.2262E-09, A8 = -1.0765E-10, A10 = 0.0000E + 00
29th page
K = 4.7637, A4 = 3.1439E-06, A6 = 7.8968E-09, A8 = 0.0000E + 00, A10 = 0.0000E + 00
Zoom data
WE ST TE
Focal length 40.80 78.17 147.00
Fno 2.88 2.88 2.88
Angle of view (2ω) 29.56 ° 15.47 ° 8.30 °
Image height 10.82 10.82 10.82
BF 32.96 32.96 32.96 Total length in air 151.88 151.88 151.88 〃
Group spacing (infinite)
WE ST TE
D 6 1.000 15.086 23.724
D12 36.772 19.853 2.161
D23 2.324 3.517 2.825
D25 3.341 8.317 9.890
D27 7.492 4.156 12.329
Group spacing (distance between objects 0.7m)
WE ST TE
D 0 546.700 546.700 546.700
D 6 1.000 15.086 23.724
D12 36.772 19.853 2.161
D23 2.860 5.494 9.546
D25 3.000 7.582 11.985
D27 7.297 2.914 3.513
Each group focal length f1 73.156
f2 -21.320
f3 22.948
f4 -17.005
f5 99.531
f6 57.513

Numerical example 7
Surface data surface number r d nd νd
1 69.4893 6.860 1.48749 70.23
2 565.7563 0.150
3 49.6451 2.000 1.90366 31.32
4 35.4454 1.840
5 35.6044 10.250 1.43875 94.93
6 1710.8247 D6 (variable)
7 120.4454 5.550 1.91082 35.25
8 -44.7712 1.600 1.73400 51.47
9 21.0744 3.070 1.92286 20.88
10 29.6069 4.910
11 -36.2415 1.500 1.83400 37.16
12 86.6417 D12 (variable)
13 Brightness stop ∞ 1.250
14 27.7712 4.350 1.74400 44.78
15 223.0077 1.100
16 22.9349 3.890 1.43875 94.93
17 57.3117 1.400 1.90366 31.32
18 17.2397 4.250 1.49700 81.54
19 62.1173 0.150
20 * 20.4824 4.280 1.59201 67.02
21 * -106.2208 D21 (variable)
22 * -125.2693 1.200 1.72903 54.04
23 * 16.2033 D23 (variable)
24 87.2011 1.200 1.78472 25.68
25 41.6649 D25 (variable)
26 77.9370 4.430 1.83400 37.16
27 * -42.7999 30.335
28 ∞ 4.000 1.51633 64.14
29 ∞ 0.800
Image plane (imaging plane)
Aspheric coefficient 20th surface
K = 1.2982, A4 = -3.2411E-05, A6 = -4.4282E-08, A8 = -8.3773E-10, A10 = 5.0168E-12
21st page
K = 0, A4 = 2.4624E-05, A6 = 6.0342E-08, A8 = -7.2514E-10, A10 = 9.1331E-12
22nd page
K = 0, A4 = -3.2217E-05, A6 = 9.1917E-07, A8 = -1.2951E-08, A10 = 7.1111E-11
23rd page
K = -1.6218, A4 = -2.7136E-06, A6 = 1.0068E-06, A8 = -1.6727E-08, A10 = 1.0766E-10
27th page
K = 1.0102, A4 = -7.9365E-07, A6 = -1.8224E-09, A8 = 0.0000E + 00, A10 = 0.0000E + 00
Zoom data
WE ST TE
Focal length 40.80 77.80 147.00
Fno 2.88 2.88 2.88
Angle of view (2ω) 29.80 ° 15.58 ° 8.27 °
Image height 10.82 10.82 10.82
BF 33.77 33.77 33.77 Total length in air 151.88 151.88 151.88 〃
Group spacing (infinite)
WE ST TE
D 6 1.000 17.244 27.378
D12 38.494 20.553 2.196
D21 1.826 2.949 2.808
D23 6.757 5.448 16.499
D25 4.804 6.687 4.000
Group spacing (distance between objects 0.7m)
WE ST TE
D 0 546.700 546.700 546.700
D 6 1.000 17.244 27.378
D12 38.494 20.553 2.196
D21 2.387 4.989 9.772
D23 6.978 3.527 4.962
D25 4.022 6.568 8.573
Each group focal length f1 89.618
f2 -24.217
f3 21.418
f4 -19.610
f5 -102.868
f6 33.689

  FIGS. 8 to 21 are graphs showing various aberrations in the first to seventh embodiments at (a) the wide angle end (WE), (b) the intermediate focal length state (ST), and (c) the telephoto end (TE). . FIGS. 8, 10, 12, 14, 16, 18, and 20 are aberration diagrams at the infinite object point of the zoom lens of each example. FIGS. 9, 11, 13, 15, 17, 19, and 21 are aberration diagrams of the zoom lens of each example at an object-image distance of 0.7 m (closest state).

  In these various aberration diagrams, SA represents spherical aberration, AS represents astigmatism, DT represents distortion, and CC represents lateral chromatic aberration. The spherical aberration SA is shown for each wavelength of 587.6 nm (d line: solid line), 435.8 nm (g line: long broken line), and 656.3 nm (C line: short broken line). The lateral chromatic aberration CC is shown for each wavelength of 435.8 nm (g line: long broken line) and 656.3 nm (C line: short broken line) with respect to the d line. In the astigmatism AS, a solid line indicates a sagittal image plane and a broken line indicates a meridional image plane. FNO indicates an F number. FIY indicates the image height.

About the said Examples 1-7, the value of each component and the value of each conditional expression (1)-(9) are shown below.

Example 1 Example 2 Example 3 Example 4
Conditional expression (1) 0.383 0.433 0.414 0.510
Conditional expression (2) 3.828 3.057 2.547 2.597
Conditional expression (3) 94.93 94.93 94.93 94.93
Conditional expression (4) 1.685 2.065 2.318 1.913
Conditional expression (5) 1.285 1.189 1.267 1.493
Conditional expression (6) 2.740 0.708 0.712 0.399
Conditional expression (6-1) 2.740 0.708 0.712 0.399
Conditional expression (6-2)
Conditional expression (7) 0.900 0.478 0.515 1.019
Conditional expression (8) 3.603 3.603 3.603 3.603
Conditional expression (9) 2.88 2.88 2.88 2.88

Example 5 Example 6 Example 7
Conditional expression (1) 0.602 0.518 0.463
Conditional expression (2) 2.840 2.972 2.779
Conditional expression (3) 81.54 81.54 94.93
Conditional expression (4) 1.909 2.444 1.972
Conditional expression (5) 1.368 1.442 1.297
Conditional expression (6) 0.336 -0.340 0.353
Conditional expression (6-1) 0.336 0.353
Conditional expression (6-2) -0.340
Conditional expression (7) 0.540 1.312 0.657
Conditional expression (8) 3.603 3.603 3.603
Conditional expression (9) 2.88 2.88 2.88

  Each embodiment achieves a large-diameter and high-performance telephoto zoom lens that can be used as an interchangeable lens and is suitable for moving image shooting.

  FIG. 22 is a cross-sectional view of a single-lens mirrorless camera as an image pickup apparatus using the zoom lens of the present embodiment and using a small CCD or CMOS as an image pickup device. In FIG. 22, 1 is a single-lens mirrorless camera, 2 is an imaging lens system disposed in the lens barrel, 3 is a lens barrel mounting portion that allows the imaging lens system 2 to be attached to and detached from the single-lens mirrorless camera 1, and a screw A mount of type or bayonet type is used. In this example, a bayonet type mount is used. Reference numeral 4 denotes an image sensor surface, and 5 denotes a back monitor.

 As the imaging lens system 2 of the single-lens mirrorless camera 1 having such a configuration, for example, the zoom lens of the present embodiment shown in Examples 1 to 7 is used.

  23 and 24 are conceptual diagrams of the configuration of the imaging apparatus according to the present embodiment in which the zoom lens is incorporated in the photographing optical system 41. FIG. FIG. 23 is a front perspective view showing an appearance of a digital camera 40 as an image pickup apparatus, and FIG. 24 is a rear perspective view of the same.

  The digital camera 40 of this embodiment includes a photographing optical system 41 positioned on the photographing optical path 42, a shutter button 45, a liquid crystal display monitor 47, and the like. When the shutter button 45 disposed on the upper part of the digital camera 40 is pressed, In conjunction with this, photographing is performed through the photographing optical system 41, for example, the lens system of the first embodiment. An object image formed by the photographing optical system 41 is formed on an image sensor (photoelectric conversion surface) provided in the vicinity of the imaging surface. The object image received by the image sensor is displayed on the liquid crystal display monitor 47 provided on the back of the camera as an electronic image by the processing means. In addition, the photographed electronic image can be recorded in a recording unit.

  FIG. 25 to FIG. 27 are conceptual diagrams of configurations of other imaging apparatuses in which the zoom lens is incorporated in the photographing optical system 41. 25 is a front perspective view showing the appearance of the digital camera 40, FIG. 26 is a rear view thereof, and FIG. 27 is a schematic cross-sectional view showing the configuration of the digital camera 40.

  In this example, the digital camera 40 includes a photographic optical system 41 positioned on the photographic optical path 42, a finder optical system 43 positioned on the finder optical path 44, a shutter button 45, a pop-up flash 46, a liquid crystal display monitor 47, and the like. In addition, when a shutter button 45 disposed on the upper portion of the camera 40 is pressed, photographing is performed through the photographing optical system 41, for example, the lens of the first embodiment, in conjunction therewith. The object image formed by the photographing optical system 41 is formed on the image pickup surface (photoelectric conversion surface) of the CCD 49 as an image pickup element provided in the vicinity of the image forming surface. The object image received by the CCD 49 is displayed as an electronic image on the liquid crystal display monitor 47 provided on the back of the camera or the finder image display element 54 via the processing means 51. Further, the processing means 51 is connected to a recording means 52 so that a photographed electronic image can be recorded.

  The recording unit 52 may be provided separately from the processing unit 51, or may be configured to perform recording and writing electronically using a flexible disk, a memory card, an MO, or the like.

  Further, a finder eyepiece lens 59 is disposed on the finder optical path 44. The object image displayed on the finder image display element 54 is magnified by the finder eyepiece lens 59 and adjusted to a diopter that is easy for the observer to see, and is guided to the observer eyeball E. A cover member 50 is disposed on the exit side of the finder eyepiece lens 59.

  FIG. 28 is a block diagram showing an internal circuit of a main part of the digital camera 40 of the present embodiment. In the following description, the processing unit 51 described above is configured by, for example, the CDS / ADC unit 24, the temporary storage memory 17, the image processing unit 18, and the like, and the storage unit 52 is configured by a storage medium unit or the like.

  As shown in FIG. 28, the digital camera 40 is connected to the operation unit 12, the control unit 13 connected to the operation unit 12, and the control signal output port of the control unit 13 via buses 14 and 15. The imaging drive circuit 16, the temporary storage memory 17, the image processing unit 18, the storage medium unit 19, the display unit 20, and the setting information storage memory unit 21 are provided.

  The temporary storage memory 17, the image processing unit 18, the storage medium unit 19, the display unit 20, and the setting information storage memory unit 21 can mutually input and output data via the bus 22. In addition, a CCD 49 and a CDS / ADC unit 24 are connected to the imaging drive circuit 16.

  The operation unit 12 includes various input buttons and switches, and notifies the control unit of event information input from the outside (camera user) via these buttons. The control unit 13 is a central processing unit composed of, for example, a CPU, and has a built-in program memory (not shown) and controls the entire digital camera 40 according to a program stored in the program memory.

  The CCD 49 is an image pickup device that is driven and controlled by the image pickup drive circuit 16, converts the light amount of each pixel of the object image formed via the image pickup optical system 41 into an electric signal, and outputs the electric signal to the CDS / ADC unit 24.

  The CDS / ADC unit 24 amplifies the electric signal input from the CCD 49, performs analog / digital conversion, and performs raw video data (Bayer data, hereinafter referred to as RAW data) obtained by performing the amplification and digital conversion. ) To the temporary memory 17.

  The temporary storage memory 17 is a buffer made of, for example, SDRAM, and is a memory device that temporarily stores RAW data output from the CDS / ADC unit 24. The image processing unit 18 reads out the RAW data stored in the temporary storage memory 17 or the RAW data stored in the storage medium unit 19 and performs various image processing based on the image quality parameter designated by the control unit 13. It is a circuit that performs it automatically.

  The storage medium unit 19 is detachably mounted with a card-type or stick-type storage medium made of, for example, a flash memory, and the RAW data transferred from the temporary storage memory 17 and the image processing unit 18 to these flash memories. Image-processed image data is recorded and held.

  The display unit 20 includes a liquid crystal display monitor 47 and the like, and displays captured RAW data, image data, an operation menu, and the like. The setting information storage memory unit 21 includes a ROM unit that stores various image quality parameters in advance, and a RAM unit that stores image quality parameters read from the ROM unit by an input operation of the operation unit 12.

  By adopting the zoom lens of the present invention as the imaging optical system 41, the digital camera 40 configured as described above can be a bright and high-performance imaging apparatus suitable for capturing moving images.

  Although various embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and embodiments configured by appropriately combining the configurations of the respective embodiments also fall within the scope of the present invention. Is.

DESCRIPTION OF SYMBOLS 1 ... Lens interchangeable camera 2 ... Imaging lens system 3 ... Mount part 4 ... Image pick-up element surface 5 ... Back monitor 12 ... Operation part 13 ... Control part 14, 15 ... Bus | bath 16 ... Imaging drive circuit 17 ... Temporary memory 18 ... Image Processing unit 19 ... Storage medium unit 20 ... Display unit 21 ... Setting information storage memory unit 22 ... Bus 24 ... CDS / ADC unit 40 ... Digital camera 41 ... Shooting optical system 42 ... Shooting optical path 45 ... Shutter button 47 ... Liquid crystal display monitor

Claims (20)

In order from the object side to the image side,
A first lens unit having positive refractive power,
A second lens unit having negative refractive power,
A third lens unit having positive refractive power,
A fourth lens unit having a negative refractive power,
A fifth lens group comprising one negative lens;
A sixth lens group having positive refractive power,
The distance between the first lens group and the second lens group is wider at the telephoto end than at the wide angle end,
The distance between the second lens group and the third lens group is narrower at the telephoto end than at the wide-angle end,
The distance between the third lens group and the fourth lens group changes during zooming from the wide-angle end to the telephoto end,
The distance between the fourth lens group and the fifth lens group changes during zooming from the wide-angle end to the telephoto end,
The distance between the fifth lens group and the sixth lens group changes during zooming from the wide-angle end to the telephoto end,
The distance between the third lens group and the first lens group, Ri Semama at the telephoto end than at the wide angle end,
Zoom lens characterized that you satisfy the following condition (6-1).
0 <(r51−r52) / (r51 + r52) <4 (6-1)
However,
r51 is a paraxial radius of curvature of the object side surface of the negative lens in the fifth lens group;
r52 is a paraxial radius of curvature of the image side surface of the negative lens in the fifth lens group;
It is. In order from the object side to the image side,
A first lens unit having positive refractive power,
A second lens unit having negative refractive power,
A third lens unit having positive refractive power,
A fourth lens unit having a negative refractive power,
A fifth lens group comprising one negative lens;
A sixth lens group having positive refractive power,
The first lens group is stationary at the time of zooming from the wide-angle end to the telephoto end,
The second lens group, the third lens group, the fourth lens group, and the fifth lens group move during zooming from the wide-angle end to the telephoto end,
The distance between the first lens group and the second lens group is wider at the telephoto end than at the wide angle end,
The distance between the second lens group and the third lens group is narrower at the telephoto end than at the wide-angle end,
The distance between the third lens group and the fourth lens group changes during zooming from the wide-angle end to the telephoto end,
The distance between the fourth lens group and the fifth lens group changes during zooming from the wide-angle end to the telephoto end,
The distance between the fifth lens group and the sixth lens group changes during zooming from the wide-angle end to the telephoto end ,
A zoom lens satisfying the following conditional expression (6-1):
0 <(r51−r52) / (r51 + r52) <4 (6-1)
However,
r51 is a paraxial radius of curvature of the object side surface of the negative lens in the fifth lens group;
r52 is a paraxial radius of curvature of the image side surface of the negative lens in the fifth lens group;
It is. In order from the object side to the image side,
A first lens unit having positive refractive power,
A second lens unit having negative refractive power,
A third lens unit having positive refractive power,
A fourth lens unit having a negative refractive power,
A fifth lens group comprising one positive lens;
A sixth lens group having positive refractive power,
The distance between the first lens group and the second lens group is wider at the telephoto end than at the wide angle end,
The distance between the second lens group and the third lens group is narrower at the telephoto end than at the wide-angle end,
The distance between the third lens group and the fourth lens group changes during zooming from the wide-angle end to the telephoto end,
The distance between the fourth lens group and the fifth lens group changes during zooming from the wide-angle end to the telephoto end,
The distance between the fifth lens group and the sixth lens group changes during zooming from the wide-angle end to the telephoto end,
The distance between the first lens group and the third lens group is narrower at the telephoto end than at the wide angle end,
Satisfies the following conditional expression (6-2)
A zoom lens characterized by that.
-1 <(r51-r52) / (r51 + r52) <0 (6-2)
However,
r51 is a paraxial radius of curvature of the object side surface of the positive lens in the fifth lens group;
r52 is a paraxial radius of curvature of the image side surface of the positive lens in the fifth lens group;
It is. In order from the object side to the image side,
A first lens unit having positive refractive power,
A second lens unit having negative refractive power,
A third lens unit having positive refractive power,
A fourth lens unit having a negative refractive power,
A fifth lens group comprising one positive lens;
A sixth lens group having positive refractive power,
The first lens group is stationary at the time of zooming from the wide-angle end to the telephoto end,
The second lens group, the third lens group, the fourth lens group, and the fifth lens group move during zooming from the wide-angle end to the telephoto end,
The distance between the first lens group and the second lens group is wider at the telephoto end than at the wide angle end,
The distance between the second lens group and the third lens group is narrower at the telephoto end than at the wide-angle end,
The distance between the third lens group and the fourth lens group changes during zooming from the wide-angle end to the telephoto end,
The distance between the fourth lens group and the fifth lens group changes during zooming from the wide-angle end to the telephoto end,
The distance between the fifth lens group and the sixth lens group changes during zooming from the wide-angle end to the telephoto end,
Satisfies the following conditional expression (6-2)
A zoom lens characterized by that.
-1 <(r51-r52) / (r51 + r52) <0 (6-2)
However,
r51 is a paraxial radius of curvature of the object side surface of the positive lens in the fifth lens group;
r52 is a paraxial radius of curvature of the image side surface of the positive lens in the fifth lens group;
It is. The first lens group is stationary when zooming from the wide-angle end to the telephoto end.
The zoom lens according to claim 1 or 3, wherein: The third lens group is located on the object side at the telephoto end with respect to the wide angle end.
The zoom lens according to claim 1, wherein: The third lens group satisfies the following conditional expression (1):
The zoom lens according to claim 6.
0.2 <ΔG3 / f3 <1 (1)
However,
ΔG3 is a displacement amount of the position of the third lens group at the telephoto end with respect to the wide angle end, and the displacement toward the object side is positive,
f3 is a focal length of the third lens group,
It is. An aperture stop disposed between the second lens group and the fourth lens group and moving toward the object side at the telephoto end with respect to the wide angle end.
The zoom lens according to claim 6 or 7, wherein: The aperture stop is disposed between the second lens group and the third lens group.
The zoom lens according to claim 8. The aperture stop has a larger aperture size at the minimum F-number at the telephoto end than at the wide-angle end.
The zoom lens according to claim 8 or 9, wherein: The fourth lens group and the fifth lens group move during zooming from the wide-angle end to the telephoto end.
The zoom lens according to claim 1, wherein the zoom lens is a zoom lens. The fourth lens group and the fifth lens group move during the focusing operation.
The zoom lens according to claim 1, wherein the zoom lens is a zoom lens. The fourth lens group and the fifth lens group move during the focusing operation, and the movement direction during focusing to a short distance at the wide-angle end and the movement direction during focusing to a short distance at the telephoto end are Different between the fourth lens group and the fifth lens group
The zoom lens according to claim 1, wherein the zoom lens is a zoom lens. The zoom lens according to any one of claims 1 to 13, wherein the sixth lens group is stationary at the time of zooming from the wide-angle end to the telephoto end. 15. The zoom lens according to claim 1, wherein the second lens group includes a three-piece cemented lens component of a positive lens, a negative lens, and a positive lens in order from the object side to the image side.
Here, the lens component is a lens block in which there are only two refracting surfaces in contact with air in the optical path, the object side surface and the image side surface. The zoom lens according to claim 15 , wherein the three-piece cemented lens component satisfies the following conditional expression (2).
1 <(r21−r22) / (r21 + r22) <5 (2)
However,
r21 is a paraxial radius of curvature of the object side surface of the negative lens in the three-piece cemented lens component;
r22 is a paraxial radius of curvature of the image side surface of the negative lens in the three-piece cemented lens component;
It is. The zoom lens according to any one of claims 1 to 16, wherein the third lens group includes a negative lens and a plurality of positive lenses, and satisfies the following conditional expressions (3) and (4). .
75 <νd3p <100 (3)
1.4 <f31p / f3 <3.7 (4)
However,
νd3p is the maximum value among the Abbe numbers on the d-line basis of all the positive lenses in the third lens group,
f31p is a focal length of a positive lens closest to the object side in the third lens group,
f3 is a focal length of the third lens group,
It is. The fourth lens group consists of one negative lens,
The zoom lens according to claim 1, wherein the following conditional expression (5) is satisfied.
0.6 <(r41−r42) / (r41 + r42) <2 (5)
However,
r41 is a paraxial radius of curvature of the object side surface of the negative lens in the fourth lens group;
r42 is a paraxial radius of curvature of the image side surface of the negative lens in the fourth lens group;
It is. At the telephoto end, the fourth lens group and the fifth lens group move while satisfying the following conditional expression (7) during focusing from the infinite focus state to the close focus state.
The zoom lens according to claim 1, wherein the zoom lens is a zoom lens.
0.2 <| ΔG5 (T) / ΔG4 (T) | <2 (7)
However,
ΔG4 (T) is the amount of movement of the fourth lens group at the telephoto end during focusing from the infinitely focused state to the closest focused state,
ΔG5 (T) is the amount of movement of the fifth lens group at the telephoto end during focusing from the infinitely focused state to the closest focused state,
It is. The following conditional expressions (8) and (9) are satisfied
The zoom lens according to claim 1, wherein the zoom lens is a zoom lens.
3.2 <ft / fw <6 (8)
1.4 <FNO (T) <3.2 (9)
However,
ft is the focal length at the telephoto end of the zoom lens,
fw is the focal length at the wide-angle end of the zoom lens,
FNO (T) is the F number at the telephoto end of the zoom lens.
It is.

Images