JP2009175324A - Zoom lens and imaging apparatus having the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a zoom lens having an image stabilization function capable of effectively performing image stabilization and generating a good image with little occurrence of decentration aberration during image stabilization.
A first lens group having a positive refractive power, a second lens group having a negative refractive power, and a subsequent lens group having a positive refractive power as a whole including a plurality of lens groups in order from the object side to the image side. A zoom lens in which the distance between the lens groups varies, and the subsequent lens group moves so as to have a component in a direction perpendicular to the optical axis and displaces the image, and has a negative refractive power A lens group Gn including Gis, a lens group Gpf having a positive refractive power on the object side of the lens group Gn, and a lens group Gpr having a positive refractive power on the image side of the lens group Gn. A negative lens NGis and a positive lens PGis are provided in order from the image side to the image side.
[Selection] Figure 1

Description

  The present invention relates to a zoom lens having an anti-vibration function used in an imaging apparatus such as a single-lens reflex camera, a digital camera, a video camera, or a film camera.

  When vibration is accidentally transmitted to the photographing system, image blur occurs. Conventionally, various zoom lenses having a mechanism (anti-vibration mechanism) for compensating for an image blur due to this accidental vibration have been proposed. For example, a zoom lens that compensates for image blur due to vibration by moving a part of a lens group constituting an optical system (zoom lens) in a direction perpendicular to the optical axis is known.

  As a zoom lens, 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, a third lens group having a positive refractive power, and a fourth lens group having a positive refractive power A 5-group zoom lens composed of a fifth lens group having a positive refractive power is known.

  In this 5-group zoom lens, the fifth lens group is composed of a negative refractive power lens group and a positive refractive power lens group, and the negative refractive power lens group is moved in a direction perpendicular to the optical axis. A zoom lens that compensates for image blur is known (Patent Document 1).

  Further, as a zoom lens, 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, a third lens group having a positive refractive power, and a fourth lens having a positive refractive power. A four-group zoom lens composed of lens groups is known. A zoom lens that compensates for image blur by moving the second lens group in a direction perpendicular to the optical axis in this four-group zoom lens is known (Patent Document 2).

  Further, as a zoom lens, 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, a third lens group having a positive refractive power, a fourth lens group, and a negative lens group. There is known a 6-group zoom lens including a fifth lens group having a refractive power and a sixth lens group having a positive refractive power. In this 6-group zoom lens, a zoom lens is known that compensates for image blur by moving the fifth lens group in a direction substantially perpendicular to the optical axis (Patent Documents 3 and 4).

  Further, the zoom lens includes, in order from the object side to the image side, first and second lens groups having positive refractive power, a third lens group having negative refractive power, and fourth and fifth lens groups having positive refractive power. A five-group zoom lens is known. In this 5-group zoom lens, the fifth lens group is composed of a positive refractive power lens group, a negative refractive power lens group, and a positive refractive power lens group, and the negative refractive power lens group is perpendicular to the optical axis. There is known a zoom lens that compensates for image blur by moving in a proper direction (Patent Document 5).

  Further, as a zoom lens, in order from the object side to the image side, a first lens unit having a positive refractive power that is fixed at the time of zooming, a second lens unit having a negative refractive power, a third lens group having a positive or negative refractive power, There is known a four-unit zoom lens composed of a fourth lens unit having a positive refractive power fixed at the time of zooming.

  In this four-group zoom lens, a zoom lens that compensates for image blur by moving a lens unit having a negative refractive power arranged in the fourth lens group in a direction perpendicular to the optical axis is known (Patent Document 6). 7).

  Further, as a zoom lens, 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, a third lens group having a positive refractive power, and a fourth lens having a negative refractive power. There is known a five-group zoom lens including a lens group and a fifth lens group having a positive refractive power. In this 5-group zoom lens, a zoom lens for a single-lens reflex camera is known that compensates for image blur by moving the fourth lens group in a direction perpendicular to the optical axis (Patent Document 8).

  Further, as a zoom lens, 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, a third lens group having a positive refractive power, and a fourth lens having a positive refractive power. A four-group zoom lens composed of lens groups is known. In this four-group zoom lens, the third lens group is composed of a positive refractive power lens group and a negative refractive power lens group, and the negative refractive power lens group is moved in a direction perpendicular to the optical axis. Zoom lenses that compensate for blurring are known (Patent Documents 9 and 10).

  Further, the zoom lens 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 group having a positive refractive power. A zoom lens that performs zooming by changing the interval between the lens groups is known.

Among these zoom lenses, zoom lenses that correct image blur by moving all or part of the second lens group in a direction perpendicular to the optical axis are known (Patent Documents 11 and 12).
JP-A-5-224160 JP-A-8-136862 JP-A-10-133113 JP-A-10-282413 JP 2002-162564 A JP 2001-100099 A JP 2004-126631 A JP-A-10-90601 JP 2006-106191 A JP 2006-284863 A JP 2005-106925 A JP 07-325272 A

  In general, various mechanisms are desired for obtaining a still image by vibrating a part of a lens group of a zoom lens in a direction perpendicular to the optical axis to eliminate blurring of a captured image.

  In a zoom lens having an anti-vibration function, it is important that the amount of decentration aberration is small when the anti-vibration lens group is moved in a direction orthogonal to the light beam to be in an eccentric state.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a zoom lens having an anti-vibration function capable of effectively preventing vibrations and generating less decentration aberrations during vibration prevention and maintaining a good image.

The zoom lens 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 plurality of lens groups. A subsequent lens group,
A zoom lens in which the distance between the first lens group and the second lens group increases and the distance between the second lens group and the subsequent lens group decreases during zooming from the wide-angle end to the telephoto end. There,
The succeeding lens group moves so as to have a component in a direction perpendicular to the optical axis, and a lens group Gn including a lens group Gis having a negative refractive power that displaces an image, and positive refraction on the object side of the lens group Gn. A lens group Gpf having a power, a lens group Gpr having a positive refractive power on the image side of the lens group Gn,
The lens group Gpf has an aspheric surface in which the positive refractive power decreases from the lens center to the lens periphery,
The lens group Gis has a negative lens NGis and a positive lens PGis in order from the object side to the image side.

  According to the present invention, it is possible to obtain a zoom lens having an anti-vibration function capable of effectively performing anti-vibration and generating less decentration aberration during anti-vibration and maintaining a good image.

  Embodiments of the zoom lens of the present invention and an image pickup apparatus having the same will be described below.

  In general, a mechanism for obtaining a still image by vibrating a part of a lens group of a zoom lens in a direction perpendicular to the optical axis to obtain a still image is desired as follows.

  For example, there is a demand for a large amount of image blur correction, a small amount of movement and rotation of the lens group (anti-vibration lens group) that vibrates for image blur correction, and a small overall device. ing.

  Also, if a large amount of decentration aberration, for example, decentration chromatic aberration, occurs when the anti-vibration lens group is decentered, color blurring increases due to the occurrence of decentration aberration when image blur is corrected, and the image is blurred and the image quality deteriorates. come. Therefore, in a zoom lens having an anti-vibration function, it is important that the amount of decentration aberration is small when the anti-vibration lens group is moved in a direction orthogonal to the light beam to be in an eccentric state.

  Further, if the image stabilization sensitivity (ratio ΔX / ΔH of the image blur correction amount ΔX with respect to the unit movement amount ΔH of the image stabilization lens group) is not set appropriately, the image blur is not detected when the image stabilization lens group is moved. It becomes difficult to correct effectively. For this reason, it is also important to set the anti-vibration sensitivity appropriately.

  Furthermore, it is also important that the vibration-proof lens group is lightweight and the lens outer diameter is small in order to improve the image blur correction responsiveness during image stabilization.

  Therefore, in this embodiment described below, a zoom lens capable of solving these problems will be described.

  In order to solve the above problems, a zoom lens 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 plurality of lens groups. And a subsequent lens group having a positive refractive power as a whole.

  During zooming from the wide-angle end to the telephoto end, the distance between the first lens group and the second lens group increases, and the distance between the second lens group and the subsequent lens group decreases.

  The following lens group moves so as to have a component in the direction perpendicular to the optical axis, and includes a lens group Gn including a lens group Gis having a negative refractive power that displaces the image, and positive refraction on the object side of the lens group Gn. The lens unit Gpf is composed of a lens group Gpf having a positive refractive power on the image side of the lens group Gpf.

  FIG. 1 is a lens cross-sectional view of Example 1 of the present invention. 2A, 2B, and 2C are longitudinal aberration diagrams of the first embodiment of the present invention at the wide-angle end (short focal length end), the intermediate zoom position, and the telephoto end (long focal length end). . FIGS. 3A, 3B, and 3C are lateral aberration diagrams of the first embodiment of the present invention at an image height of 10 mm at the wide-angle end, the intermediate zoom position, and the telephoto end. 4A, 4B, and 4C are lateral aberration diagrams at the time of image stabilization in which the tilt of 0.3 ° is corrected at the wide-angle end, the intermediate zoom position, and the telephoto end according to the first embodiment of the present invention. .

  FIG. 5 is a lens cross-sectional view of Example 2 of the present invention. 6A, 6B, and 6C are longitudinal aberration diagrams of the second embodiment of the present invention at the wide-angle end, the intermediate zoom position, and the telephoto end, respectively. FIGS. 7A, 7B, and 7C are lateral aberration diagrams of the image height of 10 mm at the wide-angle end, the intermediate zoom position, and the telephoto end of Example 2 of the present invention. FIGS. 8A, 8B, and 8C are lateral aberration diagrams at the time of image stabilization in which the tilt of 0.3 ° is corrected at the wide-angle end, the intermediate zoom position, and the telephoto end according to the second embodiment of the present invention. is there.

  FIG. 9 is a lens sectional view of Example 3 of the present invention. FIGS. 10A, 10B, and 10C are longitudinal aberration diagrams of the third embodiment of the present invention at the wide-angle end, the intermediate zoom position, and the telephoto end. 11A, 11B, and 11C are lateral aberration diagrams of the image height of 10 mm at the wide-angle end, the intermediate zoom position, and the telephoto end according to the third embodiment of the present invention. 12A, 12B, and 12C are lateral aberration diagrams at the time of image stabilization in which the tilt of 0.3 ° is corrected at the wide-angle end, the intermediate zoom position, and the telephoto end according to the third embodiment of the present invention. is there.

  FIG. 13 is a schematic diagram of a main part of a single-lens reflex camera (imaging device) including the zoom lens of the present invention. In the lens cross-sectional view, (a) shows the wide-angle end, (b) shows the intermediate focal length, and (c) shows the telephoto end.

  In the lens cross-sectional view, the left side is the object side (front), and the right side is the image side (rear). Each embodiment is a photographic lens used in an imaging apparatus. In the lens cross-sectional view, L1 is a first lens group having a positive refractive power, L2 is a second lens group having a negative refractive power, and LR includes a plurality of lens groups, and is a subsequent lens group having a positive refractive power as a whole. .

  The succeeding lens unit LR moves so as to have a component in a direction perpendicular to the optical axis, and includes a lens unit Gn including a lens unit Gis having a negative refractive power that displaces an image, and a positive refractive power on the object side of the lens unit Gn. Lens group Gpf and a lens group Gpr having a positive refractive power on the image side of the lens group Gn.

  IP is an image plane, and when used as an imaging optical system for a video camera or a digital still camera, a solid-state imaging element (photoelectric conversion element) for receiving an image formed by an imaging optical system such as a CCD sensor or a CMOS sensor. ). Or in the case of a camera for a silver salt film, it corresponds to a photosensitive surface such as a film surface. SP is an aperture stop. The wide-angle end and the telephoto end are zoom positions when the zoom lens unit is positioned at both ends of a range in which the zoom lens group can move on the optical axis in the mechanism.

The arrow indicates the movement locus of each lens unit during zooming from the wide-angle end to the telephoto end.
During zooming from the wide-angle end to the telephoto end, the distance between the first lens group L1 and the second lens group L2 increases, and the distance between the second lens group L2 and the subsequent lens group LR decreases. Has moved.

  More specifically, the relationship between the second lens unit L2 and each lens unit constituting the subsequent lens unit LR during zooming from the wide-angle end to the telephoto end is as follows.

  Each lens group is configured such that the distance between the second lens group L2 and the lens group Gpf decreases, the distance between the lens group Gpf and the lens group Gn increases, and the distance between the lens group Gn and the lens group Gpr decreases. Is moving.

  The lens group Gpf and the lens group Gpr are moved integrally during zooming, but may be moved independently.

  In the specification, the lens group includes a case where the lens group is composed of a plurality of lenses and a case where the lens group is composed of a single lens.

  The lens group is a group of lenses that are displaced in an inseparable relationship during zooming, focusing, vibration isolation, and the like.

  In the aberration diagrams, d and g are d-line and g-line, ΔM and ΔS are meridional image surface, sagittal image surface, and lateral chromatic aberration are represented by g-line. S. C is a sine condition. Y is the image height. Fno is an F number. ω is a half angle of view.

  The zoom lens of each embodiment has a so-called positive lead type refractive power arrangement preceded by a lens unit having a positive refractive power (located on the object side). This makes it easy to increase the focal length at the telephoto end.

  The subsequent lens group LR is composed of a lens group Gpf having a positive refractive power, a lens group Gn having a negative refractive power, and a lens group Gpr having a positive refractive power in order from the object side to the image side. The lens group Gn includes a lens unit Gis having a negative refractive power that moves in a direction having a component substantially perpendicular to the optical axis and displaces the image position (perpendicular to the optical axis), that is, performs image stabilization. is doing.

  The lens group Gis is composed of a negative lens NGis and a positive lens PGis arranged in order from the object side to the image side, and these lenses are cemented. However, the negative lens NGis and the positive lens PGis may be provided as a single lens without being joined, and the lens group Gis may include other lenses.

  By converging the incident light beam to the lens group Gis by the lens group Gpf, the effective diameter of the lens group Gis can be easily reduced. In addition, by making the refractive power of the lens group Gis different from the refractive power of the subsequent lens group LR, it is easy to ensure sufficient negative refractive power of the lens group Gis, and the vibration proof sensitivity of the lens group Gis is high. It is trying to become.

  Furthermore, by arranging the lens unit Gpr having a positive refractive power on the most image side of the subsequent lens unit LR, the back focus at the wide-angle end becomes long, and as a result, the focal length at the wide-angle end tends to be short. Yes.

  In general, in order to reduce deterioration in image forming performance during image stabilization, it is preferable to reduce various aberrations of each lens unit closer to the object side than the image stabilization lens unit.

  In each embodiment, an aspherical surface having a positive refractive power that weakens from the lens center toward the lens periphery is disposed in the object-side lens group Gpf of the lens group Gis that is the anti-vibration lens group.

  As a result, spherical aberration is corrected well at the telephoto end, and deterioration of imaging performance during image stabilization is suppressed. Furthermore, in each embodiment, in order to satisfactorily correct coma at the telephoto end during image stabilization, the lens group Gis is composed of a negative lens NGis and a positive lens PGis in order from the object side to the image side.

  In order from the object side to the image side, the lens group Gpr includes a lens group Gpr1 composed of a positive lens and a lens group Gpr2 composed of a cemented lens of a positive lens and a negative lens.

  Among the lens groups Gpr, an aspherical surface in which the positive refractive power is weakened from the lens center toward the lens periphery is disposed in the lens group Gpr2 where the off-axis light beam passes through a position away from the optical axis. Thereby, the distortion aberration at the wide-angle end is corrected well.

  As described above, according to each embodiment, it is possible to maintain good optical performance over the entire zoom range while having a high zoom ratio including the standard zoom range.

  Even when a mechanism for vibration compensation (anti-vibration) is provided, the entire apparatus can be easily downsized. Furthermore, a zoom lens having an anti-vibration function capable of obtaining a good image even during vibration compensation can be obtained.

  In each embodiment, it is preferable to configure so as to satisfy one or more of the following conditions.

The lens group Gpr1 includes a positive lens PGpr1 and is set to an Abbe number νPGpr1 of the material of the positive lens PGpr1. At this time, 72 <νPGpr1 <97 (1)
It is good to satisfy the condition.

  Conditional expression (1) is for satisfactorily correcting axial chromatic aberration at the telephoto end by appropriately setting the Abbe number of the material of the positive lens PGpr1 in the lens group Gpr1 in which the beam diameter is increased.

  If the conditional expression (1) is not satisfied, it will be difficult to correct longitudinal chromatic aberration at the telephoto end. More preferably, the numerical range of conditional expression (1) is set to the following range.

80 <νPGpr1 <97 (1a)
The negative lens NGis and the positive lens PGis are cemented, and the cemented surface is preferably convex toward the object side.

  By using the negative lens NGis and the positive lens PGis as a cemented lens, the lens barrel structure that holds the lens group Gis is simplified. In addition, the weight of the lens barrel can be easily reduced, and the actuator for driving the lens group Gis during vibration isolation can be downsized. Further, by making the cemented lens surface of the cemented lens convex toward the object side, it becomes easy to obtain negative refractive power by the negative lens NGis and the positive lens PGis.

  The lens group Gpf includes, in order from the object side to the image side, a lens configuration in which a negative lens NGpf having a convex surface on the object side and a meniscus shape and a positive lens PGpf having a convex surface on the object side are sequentially arranged. Good to do.

  This makes it easier to correct spherical aberration more satisfactorily on the object side than the anti-vibration lens group Gis, particularly at the telephoto end.

The refractive indexes of the materials of the negative lens NGpf and the positive lens PGpf are NNGpf and NPGpf, respectively. At this time, 0.1 <NNGpf-NPGpf (2)
It is good to satisfy the condition.

  If the conditional expression (2) is not satisfied, it will be difficult to satisfactorily correct spherical aberration at the telephoto end. More preferably, the numerical range of conditional expression (2) is set as follows.

0.2 <NNGpf-NPGpf (2a)
It is preferable that the negative lens NGpf and the positive lens PGpf constituting the lens group Gpf are cemented.

  According to this, since the eccentric error at the time of assembly can be reduced, it becomes easy to suppress the manufacturing variation in optical performance.

  During zooming from the wide-angle end to the telephoto end, it is preferable to move the lens group Gn and the lens group Gpr so that the distance between them decreases.

  According to this, it becomes easy to ensure a large zoom ratio and anti-vibration sensitivity.

  The lens group Gn preferably includes a lens group Gisr having a negative refractive power whose distance from the lens group Gis is unchanged during zooming on the image side of the lens group Gis. The lens group Gis is an anti-vibration lens group, and the lens group Gis and the lens group Gisr are integrated into a lens group GN for zooming.

  As a result, even if the lens group Gis has an optimum refractive power for image stabilization, the lens group Gisr can correct the lens group Gis to an optimum refractive power as a variable power lens group. For this reason, it becomes easy to perform high zoom ratio (high zoom ratio) and good image stabilization.

  Further, since the distance between the lens group Gis and the lens group Gisr is not changed, the lens barrel structure does not become complicated.

  During zooming from the wide-angle end to the telephoto end, it is preferable to move the lens group Gpf and the lens group Gn so that the distance between them increases. According to this, since the axial light beam emitted from the lens group Gpf can be well converged and incident on the lens group Gn at the telephoto end where the axial light beam diameter becomes large, the lens group Gn can be easily downsized. .

  The focal lengths of the first and second lens units L1 and L2 are f1 and f2, respectively. The focal lengths of the lens group Gpf, the lens group Gis, the lens group Gpr, and the lens group Gisr are sequentially set as fGpf, fGis, fGpr, and fGisr. Let ft be the focal length of the entire system at the telephoto end.

  At this time, it is preferable to satisfy any one of the following conditions.

0.27 <f1 / ft <0.75 (3)
0.04 <| f2 | / ft <0.11 (4)
0.06 <fGpf / ft <0.19 (5)
0.05 <| fGis | / ft <0.48 (6)
0.11 <fGpr / ft <0.45 (7)
0.69 <fGis / fGisr <1.14 (8)
Conditional expression (3) defines the focal length of the first lens unit L1. If it is within the upper limit value of conditional expression (3), it becomes easy to secure a bright F number at the telephoto end. Further, if it is within the lower limit, it becomes easy to correct spherical aberration at the telephoto end.

  Desirably, the numerical range of conditional expression (3) should be set to the following range.

0.33 <f1 / ft <0.69 (3a)
Conditional expression (4) defines the focal length of the second lens unit L2. If it is within the upper limit value of conditional expression (4), it is easy to ensure a high zoom ratio. Also, if it is within the lower limit value, it becomes easy to suppress the variation in field curvature due to zooming. Desirably, the numerical range of conditional expression (4) should be set to the following range.

0.05 <| f2 | / ft <0.10 (4a)
Conditional expression (5) defines the focal length of the lens group Gpf. If it is within the upper limit value of the conditional expression (5), the lens group Gis can be easily downsized. Also, if it is within the lower limit, it becomes easy to suppress the variation of spherical aberration due to zooming. Desirably, the numerical range of conditional expression (5) should be set to the following range.

0.08 <fGpf / ft <0.17 (5a)
Conditional expression (6) defines the focal length of the lens group Gis. If it is within the upper limit value of the conditional expression (6), it is easy to ensure high anti-vibration sensitivity. Further, if it is within the lower limit value, it becomes easy to correct coma generated during image stabilization. Desirably, the numerical range of conditional expression (6) is set to the following range.

0.10 <| fGis | / ft <0.43 (6a)
Conditional expression (7) defines the focal length of the lens group Gpr. If it is within the upper limit value of conditional expression (7), it is easy to ensure a high zoom ratio. Also, if it is within the lower limit value, it becomes easy to suppress the variation in field curvature due to zooming. Desirably, the numerical range of conditional expression (7) is set to the following range.

0.12 <fGpr / ft <0.40 (7a)
More preferably,
0.134 <fGpr / ft <0.250 (7b)
Conditional expression (8) defines the focal length of the lens group Gisr. If it is within the upper limit value of conditional expression (8), it is easy to ensure a high zoom ratio. Further, if it is within the lower limit value, it becomes easy to correct coma at the telephoto end. Desirably, the numerical range of conditional expression (8) is set to the following range.

0.75 <fGis / fGisr <1.09 (8a)
In each embodiment, focusing from an infinitely distant object to a close object may be performed by moving the entire optical system or a part of a lens group. Preferably, the second lens unit L2 is moved to the object side.

  In the zoom lens of each embodiment, the distance between the lens group Gpf and the lens group Gn and the distance between the lens group Gn and the lens group Gpr change in the subsequent lens group LR during zooming.

  Therefore, the lens group Gpf is regarded as the third lens group, the lens group Gn is regarded as the fourth lens group, the lens group Gpr is regarded as the fifth lens group, and the zoom lens of each embodiment as a whole is composed of five lens groups. It can also be handled as a lens.

  As described above, according to each embodiment, it is possible to maintain good optical performance over the entire zoom range while having a high zoom ratio, and to obtain a good image for vibration compensation (anti-vibration).

  In particular, it is possible to obtain a zoom lens suitable for a photographic camera, a video camera, an electronic still camera, a digital camera, a 3-CCD compatible electronic camera, and the like that stabilize a captured image.

  Next, an embodiment of a single-lens reflex camera system (imaging device) using the zoom lens of the present invention will be described with reference to FIG.

  In FIG. 13, 10 is a single-lens reflex camera body, and 11 is an interchangeable lens equipped with a zoom lens according to the present invention. Reference numeral 12 denotes a recording unit such as a film or an image sensor for recording a subject image obtained through the interchangeable lens 11. Reference numeral 13 denotes a finder optical system for observing a subject image from the interchangeable lens 11, and reference numeral 14 denotes a rotating quick return mirror for switching and transmitting the subject image from the interchangeable lens 11 to the recording means 12 and the finder optical system 13. When observing the subject image with the finder, the subject image formed on the focusing plate 15 via the quick return mirror 14 is made into an erect image with the pentaprism 16 and then magnified and observed with the eyepiece optical system 17.

  At the time of shooting, the quick return mirror 14 rotates in the direction of the arrow, and the subject image is formed and recorded on the recording means 12. Reference numeral 18 denotes a submirror, and 19 denotes a focus detection device.

  Thus, by applying the zoom lens of the present invention to an imaging device such as an interchangeable lens such as a single-lens reflex camera, an imaging device having high optical performance can be realized.

  It should be noted that the present invention can be similarly applied to a single-lens reflex camera without a quick return mirror. Further, the present invention can be similarly applied to a projection lens for a projector.

  Next, numerical examples 1 to 3 corresponding to the first to third embodiments of the present invention will be described. In each numerical example, i indicates the order of the optical surfaces from the object side, Ri is the radius of curvature of the i-th optical surface (i-th surface), Di is the distance between the i-th surface and the i + 1-th surface, Ni And νi represent the refractive index and Abbe number of the material of the i-th optical member with respect to the d-line, respectively.

  When A, B, C, D, and E are aspheric coefficients, and X is the displacement in the optical axis direction at the position of the height H from the optical axis, the aspheric shape is

Is displayed. Where R is the paraxial radius of curvature.

Further, for example, the display of “e-Z” means “10 ^−Z ”. Table 1 shows the correspondence with the above-described conditional expressions in each numerical example. f represents a focal length, Fno represents an F number, and ω represents a half angle of view.

Numerical example 1
f = 18.60-193.23 Fno = 3.60-5.88 2ω = 72.6-8.1
R 1 = 137.336 D 1 = 2.00 N 1 = 1.806100 ν 1 = 33.3
R 2 = 54.813 D 2 = 9.35 N 2 = 1.496999 ν 2 = 81.5
R 3 = -433.462 D 3 = 0.15
R 4 = 54.024 D 4 = 6.20 N 3 = 1.603112 ν 3 = 60.6
R 5 = 383.450 D 5 = Variable
R 6 = 80.126 D 6 = 1.20 N 4 = 1.834807 ν 4 = 42.7
R 7 = 13.369 D 7 = 5.98
R 8 = -31.496 D 8 = 0.90 N 5 = 1.772499 ν 5 = 49.6
R 9 = 72.963 D 9 = 0.15
R10 = 26.229 D10 = 5.60 N 6 = 1.805181 ν 6 = 25.4
R11 = -26.229 D11 = 0.38
R12 = -22.000 D12 = 0.85 N 7 = 1.772499 ν 7 = 49.6
R13 = 91.549 D13 = variable
R14 = Aperture D14 = 0.57
R15 = 32.210 D15 = 3.10 N 8 = 1.583126 ν 8 = 59.4
* R16 = -83.830 D16 = 0.15
R17 = 25.667 D17 = 0.90 N 9 = 1.805181 ν 9 = 25.4
R18 = 14.762 D18 = 4.90 N10 = 1.487490 ν10 = 70.2
R19 = -40.116 D19 = variable
R20 = -81.012 D20 = 0.70 N11 = 1.712995 ν11 = 53.9
R21 = 13.552 D21 = 2.20 N12 = 1.806100 ν12 = 33.3
R22 = 34.802 D22 = 3.05
R23 = -20.347 D23 = 1.10 N13 = 1.834807 ν13 = 42.7
R24 = -49.082 D24 = variable
R25 = 38.032 D25 = 6.25 N14 = 1.496999 ν14 = 81.5
R26 = -23.501 D26 = 3.41
* R27 = 160.167 D27 = 8.70 N15 = 1.583126 ν15 = 59.4
R28 = -14.217 D28 = 2.01 N16 = 1.834807 ν16 = 42.7
R29 = -51.096

Focal length 18.60 49.94 193.23
Variable interval
D 5 2.16 27.19 54.51
D13 24.99 13.41 2.85
D19 2.63 5.84 7.99
D24 6.00 2.79 0.64

Aspheric coefficient
16th: A = 0.00000e + 00 B = 9.19247e-06 C = 5.07959e-09 D = 0.00000e + 00
E = 0.00000e + 00 F = 0.00000e + 00
27th: A = 0.00000e + 00 B = -1.00175e-05 C = -6.53404e-09 D = -1.88855e-12
E = 4.62133e-13 F = 0.00000e + 00

Focal length L1 of each lens group: 90.986
L2: −13.133
Gpf: 22.315
Gis: -39.673
Gisr: -42.371
Gpr: 28.750

Numerical example 2
f = 17.60 to 120.97 Fno = 3.60 to 5.88 2ω = 75.6 to 12.9
R 1 = 113.052 D 1 = 2.00 N 1 = 1.806100 ν 1 = 33.3
R 2 = 45.538 D 2 = 9.60 N 2 = 1.496999 ν 2 = 81.5
R 3 = -469.111 D 3 = 0.15
R 4 = 43.257 D 4 = 6.20 N 3 = 1.603112 ν 3 = 60.6
R 5 = 260.146 D 5 = Variable
R 6 = 58.188 D 6 = 1.20 N 4 = 1.834807 ν 4 = 42.7
R 7 = 11.683 D 7 = 5.40
R 8 = -26.237 D 8 = 0.90 N 5 = 1.772499 ν 5 = 49.6
R 9 = 44.092 D 9 = 0.15
R10 = 22.602 D10 = 5.30 N 6 = 1.805181 ν 6 = 25.4
R11 = -22.602 D11 = 0.55
R12 = -17.931 D12 = 0.85 N 7 = 1.772499 ν 7 = 49.6
R13 = 119.093 D13 = Variable
R14 = Aperture D14 = 0.75
R15 = 26.731 D15 = 2.80 N 8 = 1.583126 ν 8 = 59.4
* R16 = -66.210 D16 = 0.15
R17 = 23.977 D17 = 0.90 N 9 = 1.805181 ν 9 = 25.4
R18 = 13.309 D18 = 4.00 N10 = 1.487490 ν10 = 70.2
R19 = -33.670 D19 = variable
R20 = -116.501 D20 = 0.70 N11 = 1.712995 ν11 = 53.9
R21 = 13.751 D21 = 2.15 N12 = 1.806100 ν12 = 33.3
R22 = 35.332 D22 = 2.74
R23 = -19.371 D23 = 1.10 N13 = 1.834807 ν13 = 42.7
R24 = -42.284 D24 = variable
R25 = 43.323 D25 = 5.70 N14 = 1.496999 ν14 = 81.5
R26 = -18.948 D26 = 0.14
* R27 = 158.542 D27 = 8.00 N15 = 1.583126 ν15 = 59.4
R28 = -13.343 D28 = 1.33 N16 = 1.834807 ν16 = 42.7
R29 = -62.959

Focal length 17.60 35.00 120.97
Variable interval
D 5 1.86 15.35 39.44
D13 16.64 9.81 2.67
D19 1.07 3.74 6.30
D24 5.89 3.22 0.65

Aspheric coefficient
16 sides: A = 0.00000e + 00 B = 1.70018e-05 C = 3.78059e-08 D = 0.00000e + 00
E = 0.00000e + 00 F = 0.00000e + 00
27th surface: A = 0.00000e + 00 B = -1.45576e-05 C = 1.23575e-08 D = -1.64913e-10
E = 5.18922e-13 F = 0.00000e + 00

Focal length L1 of each lens group: 76.443
L2: -10.858
Gpf: 19.175
Gis: -45.074
Gisr: −43.776
Gpr: 28.082

Numerical Example 3
f = 18.60 ~ 241.39 Fno = 3.52 ~ 5.88 2ω = 72.6 ~ 6.5
R 1 = 121.934 D 1 = 2.00 N 1 = 1.806100 ν 1 = 33.3
R 2 = 55.596 D 2 = 9.80 N 2 = 1.438750 ν 2 = 95.0
R 3 = -453.298 D 3 = 0.15
R 4 = 56.576 D 4 = 6.20 N 3 = 1.603112 ν 3 = 60.6
R 5 = 573.295 D 5 = variable
* R 6 = 83.423 D 6 = 1.20 N 4 = 1.834807 ν 4 = 42.7
R 7 = 14.382 D 7 = 6.49
R 8 = -28.585 D 8 = 0.90 N 5 = 1.772499 ν 5 = 49.6
R 9 = 91.593 D 9 = 0.15
R10 = 31.426 D10 = 5.80 N 6 = 1.805181 ν 6 = 25.4
R11 = -25.522 D11 = 0.31
R12 = -22.104 D12 = 0.85 N 7 = 1.772499 ν 7 = 49.6
R13 = 147.713 D13 = variable
R14 = Aperture D14 = 0.36
R15 = 37.621 D15 = 3.65 N 8 = 1.583126 ν 8 = 59.4
* R16 = -56.395 D16 = 0.15
R17 = 25.674 D17 = 0.90 N 9 = 1.805181 ν 9 = 25.4
R18 = 15.075 D18 = 6.10 N10 = 1.487490 ν10 = 70.2
R19 = -45.412 D19 = variable
* R20 = -61.946 D20 = 0.70 N11 = 1.712995 ν11 = 53.9
R21 = 13.489 D21 = 2.60 N12 = 1.806100 ν12 = 33.3
R22 = 36.833 D22 = 2.69
R23 = -31.753 D23 = 1.10 N13 = 1.834807 ν13 = 42.7
R24 = -177.760 D24 = variable
R25 = 30.165 D25 = 6.28 N14 = 1.438750 ν14 = 95.0
R26 = -30.077 D26 = 7.12
* R27 = 129.268 D27 = 8.70 N15 = 1.583126 ν15 = 59.4
R28 = -16.209 D28 = 2.51 N16 = 1.834807 ν16 = 42.7
R29 = -58.384

Focal length 18.60 50.00 241.39
Variable interval
D 6 2.26 27.08 57.98
D14 30.73 16.47 2.77
D20 1.25 5.12 8.74
D25 8.14 4.28 0.66

Aspheric coefficient
7th: A = 0.00000e + 00 B = 1.30501e-06 C = 6.31272e-09 D = -1.09764e-10
E = 3.91740e-13 F = 0.00000e + 00
17th: A = 0.00000e + 00 B = 8.49584e-06 C = -2.73738e-09 D = 0.00000e + 00
E = 0.00000e + 00 F = 0.00000e + 00
21 side: A = 0.00000e + 00 B = 1.30444e-06 C = -3.13146e-09 D = 0.00000e + 00
E = 0.00000e + 00 F = 0.00000e + 00
28th surface: A = 0.00000e + 00 B = -1.00183e-05 C = -3.55293e-08 D = 1.46024e-10
E = -5.97622e-13 F = 0.00000e + 00

Focal length L1 of each lens group: 94.406
L2: -13.688
Gpf: 22.540
Gis: -37.443
Gisr: -46.468
Gpr: 32.908

It is sectional drawing of Example 1 of this invention. It is a longitudinal aberration diagram of Example 1 of the present invention. It is a longitudinal aberration diagram of Example 1 of the present invention. It is a longitudinal aberration diagram of Example 1 of the present invention. FIG. 5 is a lateral aberration diagram of an image height of 10 mm according to Example 1 of the present invention. It is a lateral aberration figure at the time of 0.3 degree anti-vibration of Example 1 of this invention. It is a lateral aberration figure at the time of 0.3 degree anti-vibration of Example 1 of this invention. It is a lateral aberration figure at the time of 0.3 degree anti-vibration of Example 1 of this invention. It is sectional drawing of Example 2 of this invention. It is a longitudinal aberration figure of Example 2 of the present invention. It is a longitudinal aberration figure of Example 2 of the present invention. It is a longitudinal aberration figure of Example 2 of the present invention. FIG. 6 is a lateral aberration diagram of an image height of 10 mm according to Example 2 of the present invention. It is a lateral aberration figure at the time of 0.3 degree vibration isolation of Example 2 of this invention. It is a lateral aberration figure at the time of 0.3 degree vibration isolation of Example 2 of this invention. It is a lateral aberration figure at the time of 0.3 degree vibration isolation of Example 2 of this invention. It is sectional drawing of Example 3 of this invention. It is a longitudinal aberration diagram of Example 3 of the present invention. It is a longitudinal aberration diagram of Example 3 of the present invention. It is a longitudinal aberration diagram of Example 3 of the present invention. FIG. 6 is a lateral aberration diagram of an image height of 10 mm according to Example 3 of the present invention. It is a lateral aberration figure at the time of 0.3 degree anti-vibration of Example 3 of this invention. It is a lateral aberration figure at the time of 0.3 degree anti-vibration of Example 3 of this invention. It is a lateral aberration figure at the time of 0.3 degree anti-vibration of Example 3 of this invention. Schematic diagram of main parts of an imaging apparatus of the present invention

Explanation of symbols

L1: First lens group L2: Second lens group LR: Subsequent lens group Gn: Lens group Gis: Anti-vibration lens group Gpf: Lens group Gpr: Lens group Gisr: Lens group Gpr1: Lens group Gpr2: Lens group SP: Aperture Aperture IP: image plane d: d line g: g line ΔM: meridional image plane ΔS: sagittal image plane C: Sine condition Y: Image height Fno: F number

Claims (13)

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 subsequent lens group including a plurality of lens groups and having a positive refractive power as a whole. ,
A zoom lens in which the distance between the first lens group and the second lens group increases and the distance between the second lens group and the subsequent lens group decreases during zooming from the wide-angle end to the telephoto end. There,
The succeeding lens group moves in a direction having a component perpendicular to the optical axis, and includes a lens group Gn including a lens group Gis having a negative refractive power that displaces an image, and positive refraction toward the object side of the lens group Gn. A lens group Gpf having a power, a lens group Gpr having a positive refractive power on the image side of the lens group Gn,
The lens group Gis has a negative lens NGis and a positive lens PGis in order from the object side to the image side. The lens group Gpr includes, in order from the object side to the image side, a lens group Gpr1 and a lens group Gpr2, and the lens group Gpr2 has an aspherical surface in which the positive refractive power decreases from the lens center to the lens periphery,
The lens group Gpr1 has a positive lens PGpr1, and when the Abbe number of the material of the positive lens PGpr1 is νPGpr1, 72 <νPGpr1 <97
The zoom lens according to claim 1, wherein the following condition is satisfied.   3. The zoom lens according to claim 1, wherein the negative lens NGis and the positive lens PGis are cemented, and the cemented surface has a convex shape on the object side. The lens group Gpf has a lens configuration in which, in order from the object side to the image side, a negative lens NGpf having a convex surface on the object side and a meniscus shape, and a positive lens PGpf having a convex surface on the object side are sequentially arranged. When the refractive indexes of the materials of the negative lens NGpf and the positive lens PGpf are NNGpf and NPGpf, respectively, 0.1 <NNGpf−NPGpf
4. The zoom lens according to claim 1, wherein the zoom lens satisfies the following condition.   The zoom lens according to claim 4, wherein the negative lens NGpf and the positive lens PGpf are cemented.   6. The zoom lens according to claim 1, wherein the distance between the lens group Gn and the lens group Gpr is reduced during zooming from the wide-angle end to the telephoto end.   7. The lens group Gn includes a lens group Gisr having a negative refractive power whose distance from the lens group Gis is unchanged during zooming on the image side of the lens group Gis. 1 zoom lens.   The zoom lens according to any one of claims 1 to 7, wherein a distance between the lens group Gpf and the lens group Gn is increased during zooming from the wide-angle end to the telephoto end. The lens group Gn includes a lens group Gisr having a negative refractive power whose distance from the lens group Gis is unchanged during zooming on the image side of the lens group Gis. The focal lengths of the first and second lens groups F1, f2, the lens group Gpf, the lens group Gis, the lens group Gisr, the focal length of the lens group Gpr in this order fGpf, fGis, fGisr, fGpr, and the focal length of the entire system at the telephoto end as ft. When 0.27 <f1 / ft <0.75
0.04 <| f2 | / ft <0.11
0.06 <fGpf / ft <0.19
0.05 <| fGis | / ft <0.48
0.11 <fGpr / ft <0.45
0.69 <fGis / fGisr <1.14
The zoom lens according to claim 1, wherein at least one of the following conditions is satisfied. 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 subsequent lens group having a positive refractive power as a whole include a plurality of lens groups. And
The subsequent lens group includes a lens group Gn including a lens group Gis having a negative refractive power that moves so as to have a component perpendicular to the optical axis and displaces the image.
A lens group Gpf having a positive refractive power on the object side of the lens group Gn;
A lens unit Gpr having a positive refractive power on the image side of the lens unit Gn.
Have
During zooming from the wide-angle end to the telephoto end, the distance between the first lens group and the second lens group increases, the distance between the second lens group and the lens group Gpf decreases, and the lens group A zoom lens in which the distance between Gpf and the lens group Gn increases and the distance between the lens group Gn and the lens group Gpr decreases;
The lens group Gpf has an aspheric surface in which the positive refractive power decreases from the lens center to the lens periphery,
The lens group Gis has a negative lens NGis and a positive lens PGis in order from the object side to the image side. The lens group Gpr has a positive lens PGpr1, and the Abbe number of the material of the positive lens PGpr1 is νPGpr1,
The lens group Gpf has a lens configuration in which, in order from the object side to the image side, a negative lens NGpf having a convex surface on the object side and a meniscus shape, and a positive lens PGpf having a convex surface on the object side are sequentially arranged. When the refractive indices of the negative lens NGpf and positive lens PGpf are NNGpf and NPGpf, respectively, 72 <νPGpr1 <97
0.1 <NNGpf-NPGpf
The zoom lens according to claim 10, wherein the following condition is satisfied. The lens group Gn includes a lens group Gisr having a negative refractive power whose distance from the lens group Gis is unchanged during zooming on the image side of the lens group Gis.
The focal lengths of the first and second lens groups are f1, f2, the lens group Gpf, the lens group Gis, the lens group Gisr, and the focal lengths of the lens group Gpr in this order, fGpf, fGis, fGisr, fGpr, telephoto end. 0.27 <f1 / ft <0.75, where ft is the focal length of the entire system
0.04 <| f2 | / ft <0.11
0.06 <fGpf / ft <0.19
0.05 <| fGis | / ft <0.48
0.11 <fGpr / ft <0.45
0.69 <fGis / fGisr <1.14
12. The zoom lens according to claim 10, wherein at least one of the following conditions is satisfied.   An image pickup apparatus comprising: the zoom lens according to claim 1; and a solid-state image sensor that receives an image formed by the zoom lens.