JP6125383B2 - Zoom lens with anti-vibration function - Google Patents

Description

  The present invention relates to a zoom lens having an anti-vibration function used for a digital camera, a video camera, a silver salt camera, and the like.

  When the vibration is transmitted to the photographing system, an image blur occurs in the photographed image. The patent documents shown below disclose a zoom lens having an anti-vibration function that compensates for image blur caused by vibration.

JP 2006-227526 A JP 2009-244443 A JP 2011-164550 A JP2011-164551A

  In each of Patent Document 1, Patent Document 2, Patent Document 3, and Patent Document 4, all the examples have the fourth lens group. The fourth lens group has a negative refractive power as a whole, and moves in the direction perpendicular to the optical axis in order from the object side to compensate for image blur, or in the direction perpendicular to the optical axis. The lens unit includes a lens unit having a negative refractive power that is moved to compensate for image blur and a lens group having a negative refractive power.

  Conventional optical systems having an anti-vibration function have deteriorated in optical performance during image blur compensation. However, these Patent Documents 1 to 4 specify that good optical performance is obtained even in image blur compensation. ing. However, in any of the embodiments, as described above, the fourth lens group is only a lens group having a negative refractive power that is moved in the direction perpendicular to the optical axis to compensate for image blur, or a lens having a negative refractive power. It is the structure which added the group. Therefore, it is difficult to reduce the Petzval sum in the fourth lens group. In order to reduce the Petzval sum in the entire optical system, it is necessary to increase the Petzval sum of a lens unit having a positive refractive power. In that case, it becomes difficult for the lens group having a positive refractive power with a large Petzval sum to satisfy the generally known achromatic condition. As a result, there is a problem that it is difficult to correct axial chromatic aberration.

  From the above, Patent Documents 1 to 4 clearly stated that good optical performance was obtained even during image blur compensation, but the effect was not sufficient.

  Accordingly, the present invention solves the above-mentioned problems, has a small overall length and diameter, has good optical performance even during camera shake compensation, and further has a vibration-proof function with little zoom torque fluctuation during zooming and little focus movement. The object is to provide a lens.

The first invention, which is a means for solving the above problems, includes a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and an aperture stop S on the object side. The fourth lens group G4 includes a third lens group G3 having a positive refractive power, a fourth lens group G4 having a negative refractive power, and a fifth lens group G5 having a positive refractive power. The first lens unit includes a fourth lens unit front group G4A having negative refractive power and a fourth lens unit rear group G4B having positive refractive power in order from the object side. During zooming from the wide-angle end to the telephoto end, The distance between G1 and the second lens group G2 changes, the distance between the second lens group G2 and the third lens group G3 decreases, and the distance between the third lens group G3 and the fourth lens group G4 decreases. The interval increases, and the fourth lens group G4 and the fifth lens group G5 The distance is decreased, and the fourth lens group front group G4A is moved in a direction substantially perpendicular to the optical axis, so that the image is moved in the direction perpendicular to the optical axis and caused by camera shake or the like. In this zoom lens, the image movement can be corrected, and the following conditional expression is satisfied.
(1) 0.70 <f1 / fT <1.25
(2) -0.22 <f2 / fT <-0.10
(5) 15.00 <f2 / βW345 <22.00
f1: Focal length of the first lens group G1 f2: Focal length of the second lens group G2 fT: Focal length of the entire zoom lens system at the telephoto end
βW345: Composite magnification of the third lens group G3, the fourth lens group G4, and the fifth lens group G5 at the wide angle end

A second invention, which is a means for solving the above-mentioned problems, is a zoom lens having the image stabilization function according to the first invention, and further satisfies the following conditional expression: A zoom lens having a vibration function.
(3) -0.80 <f4A / f4B <0.00
f4A: focal length of the fourth lens group front group G4A f4B: focal length of the fourth lens group rear group G4B

A third invention, which is a means for solving the above-mentioned problems, is a zoom lens having the image stabilization function according to the first invention or the second invention, and further satisfies the following conditional expression: A zoom lens having a vibration-proof function.
(4) 0.20 <f3 / fT <0.50
f3: focal length of the third lens group G3 fT: focal length of the entire zoom lens system at the telephoto end

A fourth invention, which is means for solving the above-mentioned problems, is a zoom lens having an image stabilization function according to any one of the first to third inventions, and further the second lens group. This is a zoom lens having an anti-vibration function that performs focusing from infinity to a near object by moving G2 from the image plane side to the object side along the optical axis.

  According to the present invention, a zoom lens used in a digital camera, a silver salt camera, etc., is small in both length and diameter, has good optical performance even when camera shake compensation is performed, and zoom torque fluctuation during zooming is small and focus movement is small. It is possible to provide a zoom lens having a small anti-vibration function.

FIG. 3 is a lens configuration diagram at infinity at the wide-angle end of the zoom lens having the image stabilization function according to the first embodiment. Longitudinal aberration diagram at infinity of the wide-angle end of the zoom lens having the image stabilization function of Example 1 Longitudinal aberration diagram at infinity of the intermediate focal length (f = 52.75 mm) of the zoom lens having the image stabilization function of Example 1 Longitudinal aberration diagram at infinity of the telephoto end of the zoom lens having the image stabilization function of Example 1 Horizontal aberration diagram in the standard state at infinity at the wide-angle end of the zoom lens having the image stabilization function according to Example 1 Lateral aberration diagram in the standard state at infinity of the intermediate focal length (f = 52.75 mm) of the zoom lens having the image stabilization function of Example 1 Lateral aberration diagram in the standard state at infinity at the telephoto end of the zoom lens having the image stabilization function according to Example 1 FIG. 4 is a lateral aberration diagram at the time of 0.15 ° camera shake correction at infinity at the wide angle end of the zoom lens having the image stabilization function according to Example 1; Lateral aberration diagram at the time of 0.15 ° camera shake correction at infinity of the intermediate focal length (f = 52.75 mm) of the zoom lens having the image stabilization function of Example 1 Lateral aberration diagram at the time of 0.15 ° camera shake correction at infinity at the telephoto end of the zoom lens having the image stabilization function of Example 1 FIG. 5 is a lens configuration diagram at infinity of the wide-angle end of the zoom lens having the image stabilization function according to the second embodiment. Longitudinal aberration diagram at infinity at the wide-angle end of the zoom lens having the image stabilization function according to Example 2 Longitudinal aberration diagram at infinity of the intermediate focal length (f = 50.58 mm) of the zoom lens having the image stabilization function of Example 2 Longitudinal aberration diagram at infinity at the telephoto end of the zoom lens having the image stabilization function according to Example 2 Horizontal aberration diagram in the standard state at infinity at the wide-angle end of the zoom lens having the image stabilization function according to Example 2 Lateral aberration diagram in the standard state at infinity of the intermediate focal length (f = 50.58 mm) of the zoom lens having the image stabilization function of Example 2 Lateral aberration diagram in the standard state at infinity at the telephoto end of the zoom lens having the image stabilization function according to Example 2 Lateral aberration diagram at the time of 0.15 ° camera shake correction at infinity at the wide angle end of the zoom lens having the image stabilization function according to Example 2 Lateral aberration diagram at the time of 0.15 ° camera shake correction at infinity of the intermediate focal length (f = 50.58 mm) of the zoom lens having the image stabilization function of Example 2 Lateral aberration diagram at the time of 0.15 ° camera shake correction at infinity at the telephoto end of the zoom lens having the image stabilization function according to Example 2 FIG. 6 is a lens configuration diagram at infinity at the wide-angle end of a zoom lens having an image stabilization function according to Example 3; Longitudinal aberration diagram at infinity of the wide-angle end of the zoom lens having the image stabilization function according to Example 3 Longitudinal aberration diagram at infinity of the intermediate focal length (f = 50.00 mm) of the zoom lens having the image stabilization function of Example 3 Longitudinal aberration diagram at infinity at the telephoto end of the zoom lens having the image stabilization function according to Embodiment 3 Lateral aberration diagram in the standard state at infinity at the wide-angle end of the zoom lens having the image stabilization function according to Example 3 Lateral aberration diagram in the standard state at infinity of the intermediate focal length (f = 50.00 mm) of the zoom lens having the image stabilization function according to Example 3 Lateral aberration diagram in the standard state at infinity at the telephoto end of the zoom lens having the image stabilization function according to Example 3 Horizontal aberration diagram at the time of 0.15 ° camera shake correction at infinity at the wide angle end of the zoom lens having the image stabilization function according to Example 3 Lateral aberration diagram at the time of 0.15 ° camera shake correction at infinity of the intermediate focal length (f = 50.00 mm) of the zoom lens having the image stabilization function according to Example 3 Lateral aberration diagram at the time of 0.15 ° camera shake correction at infinity at the telephoto end of the zoom lens having the image stabilization function according to Example 3 4 is a lens configuration diagram at infinity of the wide-angle end of a zoom lens having an image stabilization function according to Example 4; Longitudinal aberration diagram at infinity of the wide-angle end of the zoom lens having the image stabilization function according to Example 4 Longitudinal aberration diagram at infinity of intermediate focal length (f = 50.54 mm) of the zoom lens having the image stabilization function according to Embodiment 4 Longitudinal aberration diagram at infinity of the telephoto end of the zoom lens having the image stabilization function according to Example 4 Lateral aberration diagram in the standard state at infinity of the wide-angle end of the zoom lens having the image stabilization function according to Example 4 Lateral aberration diagram in the standard state at the infinity of the intermediate focal length (f = 50.54 mm) of the zoom lens having the image stabilization function of Example 4 Lateral aberration diagram in the standard state at infinity at the telephoto end of the zoom lens having the image stabilization function according to Example 4 Horizontal aberration diagram at the time of 0.15 ° camera shake correction at infinity at the wide angle end of the zoom lens having the image stabilization function according to Example 4 Lateral aberration diagram at the time of 0.15 ° camera shake correction at infinity of the intermediate focal length (f = 50.54 mm) of the zoom lens having the image stabilization function of Example 4 Lateral aberration diagram at the time of 0.15 ° camera shake correction at infinity at the telephoto end of the zoom lens having the image stabilization function according to Example 4

As shown in FIGS. 1, 11, 21, and 31, the zoom lens having the image stabilization function of the present invention is a lens configuration diagram of the embodiment of the present invention shown in FIG. 1, FIG. 11, FIG. 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 an aperture stop S on the object side and having a positive refractive power; A fourth lens group G4 having a refractive power and a fifth lens group G5 having a positive refractive power, and the fourth lens group G4 has a negative refractive power in order from the object side. G4A and a fourth lens group rear group G4B having positive refractive power, and during zooming from the wide-angle end to the telephoto end, the distance between the first lens group G1 and the second lens group G2 changes, and The distance between the second lens group G2 and the third lens group G3 is Slightly, the distance between the third lens group G3 and the fourth lens group G4 increases, and the distance between the fourth lens group G4 and the fifth lens group G5 decreases. By moving the front group G4A in a direction substantially perpendicular to the optical axis, it is possible to correct image movement caused by camera shake by moving the image in a direction perpendicular to the optical axis. A zoom lens having an anti-vibration function characterized by satisfying the following conditional expression:
(1) 0.70 <f1 / fT <1.25
(2) -0.22 <f2 / fT <-0.10
f1: Focal length of the first lens group G1 f2: Focal length of the second lens group G2 fT: Focal length of the entire zoom lens system at the telephoto end

  The fourth lens group G4 of the zoom lens having the image stabilization function according to the first aspect of the invention is, in order from the object side, the fourth lens group front group G4A having negative refractive power and the rear of the fourth lens group having positive refractive power. Group G4B. By doing so, it is possible to reduce the Petzval sum of the fourth lens group G4, and it is possible to suppress the Petzval sum in the entire zoom lens system having the image stabilization function. As a result, axial chromatic aberration correction becomes easy.

  Conditional expression (1) defines the ratio between the focal length of the first lens group G1 and the focal length of the entire lens system at the telephoto end. By defining the focal length of the first lens group G1 suitable for the focal length at the telephoto end, it contributes to obtaining sufficient imaging performance at the telephoto end.

  When the lower limit of conditional expression (1) is exceeded and the refractive power of the first lens group G1 increases, the curvature tends to increase on each surface in the first lens group G1, and correction of spherical aberration and coma aberration is corrected. It becomes insufficient. In addition, it becomes difficult to correct axial chromatic aberration and lateral chromatic aberration at the telephoto end, and the secondary spectrum increases.

  If the upper limit of conditional expression (1) is exceeded and the refractive power of the first lens group G1 becomes weak, aberration correction becomes advantageous. However, since the distance between the first lens group G1 and the second lens group G2 becomes large during zooming to the telephoto end, the principal ray of the off-axis light beam at the telephoto end passes near the outer periphery of the lens, so the first lens group When trying to reduce the lens outer diameter, it is not possible to secure a sufficient amount of peripheral light especially during image stabilization.

  In addition, regarding the conditional expression (1), the lower limit value is further limited to 0.80, and the upper limit value is further limited to 1.15, whereby the above-described effect can be further ensured.

  Conditional expression (2) defines the ratio between the focal length of the second lens group G2 and the focal length at the telephoto end of the zoom lens system having the image stabilization function. By appropriately setting the focal length of the second lens group G2 having negative refracting power, it contributes to miniaturization of the entire lens length at the telephoto end.

  When the negative refracting power of the second lens group G2 increases with respect to the focal length at the telephoto end beyond the lower limit value of the conditional expression (2), the curvature of the negative lens in the second lens group tends to increase. This makes it difficult to correct spherical aberration and astigmatism at the telephoto end, which is not preferable for optical performance.

  When the negative refractive power of the second lens group G2 becomes weaker than the telephoto end focal length beyond the upper limit value of the conditional expression (2), the imaging magnification of the second lens group G2 at the telephoto end decreases. . Then, the combined imaging magnification of the third lens group G3, the fourth lens group G4, and the fifth lens group G5 at the telephoto end has to be increased, and the amount of movement of each lens group during zooming increases, zooming It becomes difficult to downsize the lens optical system. Furthermore, since negative spherical aberration that occurs greatly at the telephoto end becomes remarkable, there arises a problem that sufficient optical performance cannot be obtained at the telephoto end.

  In the above-described conditional expression (2), the lower limit value is further limited to −0.20, and the upper limit value is further limited to −0.13, whereby the above-described effect can be further ensured.

The zoom lens having the image stabilization function according to the second invention is the first invention and further satisfies the following conditional expression.
(3) -0.80 <f4A / f4B <0.00
f4A: focal length of the fourth lens group front group G4A f4B: focal length of the fourth lens group rear group G4B

  Conditional expression (3) defines the ratio of the focal lengths of the fourth lens group front group G4A and the fourth lens group rear group G4B. By making the focal length of the fourth lens group front group G4A appropriate, the optical performance at the time of camera shake compensation becomes good, and an appropriate camera shake compensation effect can be obtained.

  If the lower limit of conditional expression (3) is exceeded and the refractive power of the fourth lens group front group G4A, which is a lens group that performs camera shake compensation, becomes small, the optical performance during camera shake compensation will be good. However, it is difficult to obtain a camera shake compensation effect. Furthermore, the refractive power of the fourth lens group rear group G4B becomes strong, and the manufacturing error sensitivity due to the decentering of the entire fourth lens group G4 increases, which may reduce the optical performance during manufacturing.

  If the refractive power of the fourth lens unit front group G4A, which is a lens unit for performing camera shake compensation, exceeds the upper limit value of conditional expression (3), the decentration coma aberration or chromatic aberration correction during camera shake compensation is performed. This makes it difficult to obtain good optical performance during camera shake compensation.

  In addition, about the conditional expression (3) mentioned above, the above-mentioned effect can be made more reliable by further limiting the lower limit value to −0.50.

The zoom lens having the image stabilization function according to the third invention is the first invention or the second invention, and further satisfies the following conditional expression.
(4) 0.20 <f3 / fT <0.50
fT: focal length of the entire zoom lens system at the telephoto end f3: focal length of the third lens group G3

  Conditional expression (4) defines the ratio between the focal length of the third lens group G3 and the focal length of the entire lens system at the telephoto end. By making the focal length of the third lens group G3 appropriate, it contributes to miniaturization of the zoom lens optical system.

  When the lower limit of conditional expression (4) is exceeded and the focal length of the third lens group G3 becomes shorter than the focal length at the telephoto end, the height of the light incident on the fourth lens group G4 becomes lower, and the camera shake compensation group As the fourth lens group front group G4A becomes smaller, the drive actuator can be made smaller, which contributes to the miniaturization of the zoom lens optical system. However, the curvature of the positive lens tends to be too strong, and the sensitivity of manufacturing error due to the eccentricity of the entire third lens group G3 increases, and the optical performance at the time of manufacturing may decrease.

  When the upper limit of conditional expression (4) is exceeded and the focal length of the third lens group G3 is increased with respect to the focal length at the telephoto end, the curvature of the positive lens becomes weak and the spherical aberration at the telephoto end is improved. I can do it. However, the amount of movement of the third lens group G3 during zooming becomes large, and it is difficult to reduce the size of the zoom lens optical system.

  In the above-described conditional expression (4), the lower limit value is further limited to 0.25, and the upper limit value is further limited to 0.45, whereby the above-described effect can be further ensured.

  During zooming of the zoom lens, a plurality of cam loci are combined and combined in order to appropriately move each lens group within the lens barrel. It is desirable that the user can operate the zoom ring with a constant force during zooming. For this purpose, it is necessary to reduce the zoom torque fluctuation during zooming. Therefore, it is necessary to appropriately set a composite amount combining cam loci for performing zoom movement of each lens group.

  In the zoom lens as described above, an image suitable for the second lens group G2 can be used to reduce fluctuations in zoom torque of the first lens group G1, the third lens group G3, and the fifth lens group G5 that have a large zoom movement. It is important to have a surface correction effect. In addition, when the second lens group G2 is used for focusing, it is necessary to reduce the variation in zoom torque of the second lens group G2. In order to reduce the variation of the zoom torque of the second lens group G2, it is important to set the focal length of the second lens group G2 and the composite magnification of the lens group located on the image side from the third lens group. Furthermore, during zooming, it is necessary to appropriately set the lens interval between the first lens group G1 and the second lens group G2 in each zoom range so that the decrease in peripheral light amount does not become remarkable.

  Therefore, the movement of the second lens group G2 during zooming will be described. During zooming, it is ideal that the second lens group G2 moves along a locus that tends to increase monotonically from the image plane side toward the object side. However, during zooming from the wide-angle end to the telephoto end, in the intermediate focal range from the vicinity of the wide-angle end, the second lens group G2 makes a U-turn with a convex locus on the image plane side and moves to the object side. This is because, as the combined magnification after the third lens group G3 is smaller, the second lens group G2 performs appropriate image plane correction during zooming.

  However, in the vicinity of the wide-angle end, it is necessary to set a small interval between the first lens group G1 and the second lens group G2 in order to prevent a decrease in peripheral light amount at the time of image stabilization particularly at infinity. From the above, since the U-turn amount of the second lens group G2 becomes larger, it is necessary to appropriately set the composite magnification after the third lens group.

  Subsequently, at the telephoto end from the intermediate focal range, the amount of movement of the second lens group G2 toward the object side increases. This is because the distance between the first lens group G1 and the second lens group G2 has to be set narrow in order to prevent a decrease in the amount of peripheral light during image stabilization especially in close-up shooting.

  In order to reduce the zoom torque fluctuation during zooming and to improve the focus movement during focusing, the second lens is used to solve the problem that the locus of lens movement of the second lens group G2 tends to be U-shaped. It is important to reduce the U-shaped tendency of the zoom locus of the group G2. Therefore, it is necessary to set the focal length of the second lens group G2 and the composite magnification after the third lens group to appropriate conditions.

From the above, it is desirable that the zoom lens having the image stabilization function according to the fourth invention is any one of the first invention to the third invention and further satisfies the following conditional expression.
(5) 15.00 <f2 / βW345 <22.00
f2: Focal length βW345 of the second lens group G2: Composite magnification of the third lens group G3, the fourth lens group G4, and the fifth lens group G5 at the wide angle end

  Conditional expression (5) defines the focal length of the second lens group and the combined magnification of the third lens group G3, the fourth lens group G4, and the fifth lens group G5. Satisfying this conditional expression (5) reduces the zoom torque fluctuation during zooming and contributes to the improvement of focus movement during focusing.

  When the negative refractive power of the second lens group G2 is increased beyond the lower limit value of the conditional expression (5), the zoom torque fluctuation during zooming is reduced and the focus movement is also improved. However, it is difficult to correct astigmatism by correcting astigmatism at the wide-angle end. Furthermore, since it is necessary to use a glass material having a higher refractive index for the second lens group G2, correction of lateral chromatic aberration at the wide angle end becomes insufficient. Further, if the combined magnification βW345 after the third lens group at the wide-angle end increases and the lower limit value of the conditional expression (5) is exceeded, negative refractive power is generated by combining the first lens group G1 and the second lens group G2. Must be strengthened, so that a power arrangement that further increases the retrofocus tendency becomes a problem, so that correction of distortion at the wide-angle end becomes a problem.

  If the negative refracting power of the second lens group G2 becomes weaker than the upper limit value of the conditional expression (5), the amount of focus movement of the second lens group increases, so the first lens group and the second lens at the wide-angle end are increased. It is necessary to ensure a wide distance from the lens group, which makes it difficult to correct astigmatism. Further, if the combined magnification βW345 after the third lens group at the wide angle end becomes small and exceeds the upper limit value of the conditional expression (5), a locus can be drawn in which the second lens group G2 moves smoothly during zoom movement. It becomes difficult to reduce the zoom torque fluctuation during zooming.

  In the above-mentioned conditional expression (5), the lower limit value is further limited to 16.50, and the upper limit value is further limited to 21.00, whereby the above-described effect can be further ensured.

  The numerical data of Examples 1 to 4 relating to the above-described zoom lens having the image stabilization function of the present invention will be shown below.

  In [Surface data], the surface number is the number of the lens surface or aperture stop counted from the object side, r is the radius of curvature of each surface, d is the distance between the surfaces, nd is the refractive index with respect to the d-line (wavelength 587.56 nm). , Vd indicate Abbe numbers for the d line.

  The * (asterisk) attached to the surface number indicates that the lens surface shape is an aspherical surface. BF represents back focus.

  The (diaphragm) attached to the surface number indicates that the aperture stop S is located at that position. ∞ (infinity) is entered in the radius of curvature for the plane or aperture stop S.

In [Aspherical data], each coefficient value giving the aspherical shape of the lens surface marked with * in [Surface data] is shown. As for the aspherical shape, the aspherical shape is y for the displacement from the optical axis in the direction perpendicular to the optical axis, z for the displacement (sag amount) in the optical axis direction from the intersection of the aspherical surface and the optical axis, and the reference When the radius of curvature of the spherical surface is r, the conic coefficient is K, 4, 6, 8, and the 10th-order aspherical coefficient are A4, A6, A8, and A10, respectively, the coordinates of the aspherical surface are expressed by the following equations: And

  [Various data] shows values such as the focal length in each focal length state.

  [Variable interval data] indicates the value of the variable interval and BF (back focus) in each focal length state.

  [Lens Group Data] indicates the surface number of the most object side constituting each lens group and the combined focal length of the entire group.

  In all the values of the following specifications, the focal length f, the radius of curvature r, the lens surface interval d, and other length units described are in millimeters (mm) unless otherwise specified. In the system, the same optical performance can be obtained even in proportional expansion and proportional reduction, and the present invention is not limited to this.

  In the aberration diagrams corresponding to each example, d, g, and C represent d-line, g-line, and C-line, respectively, and ΔS and ΔM represent sagittal image plane and meridional image plane, respectively. .

  Further, in the lens configuration diagrams shown in FIGS. 1, 11, 21, and 31, I is the image plane, and the alternate long and short dash line passing through the center is the optical axis.

  FIG. 1 is a lens configuration diagram of a zoom lens having an image stabilization function according to Embodiment 1 of the present invention. In order from the object side, the first lens group G1, the second lens group G2, the third lens group G3, the fourth lens group G4, and the fifth lens group G5 are included. The first lens group G1 has a positive refractive power as a whole. A cemented lens composed of two lenses, a negative meniscus lens L1a having a convex surface facing the object side and a positive meniscus lens L1b having a convex surface facing the object side, and a positive meniscus having a convex surface facing the object side It consists of a lens L1c.

  The second lens group G2 has a negative refractive power as a whole, a negative meniscus lens L2a having a convex surface facing the object side, a biconcave negative lens L2b, a biconvex positive lens L2c, and an image. A negative meniscus lens L2d having a convex surface directed to the side, and a lens surface on the object side of the negative meniscus lens L2a is formed with a resin layer having a predetermined aspherical shape.

  The third lens group G3 has a positive refractive power as a whole, and has an aperture stop S, a biconvex positive lens L3a, a negative meniscus lens L3b having a convex surface on the object side, and a convex surface on the object side. Further, it is composed of a cemented lens composed of two lenses, a positive meniscus lens L3c, and a biconvex positive lens L3d.

  The fourth lens group G4 has a negative refractive power as a whole, and is composed of a cemented lens including two lenses, a positive meniscus lens L4a having a concave surface facing the object side and a biconcave negative lens L4b. A fourth lens group front group G4A having a negative refractive power, a positive meniscus lens L4c having a convex surface directed toward the object side, and a negative meniscus lens L4d having a concave surface directed toward the object side. The lens group rear group G4B is configured, and the image-side lens surface of the biconcave negative lens L4b has a predetermined aspherical shape. The fourth lens unit front group G4A is moved in a direction substantially perpendicular to the optical axis to perform image stabilization.

  The fifth lens group G5 has a positive refractive power as a whole, and is composed of two lenses, a biconvex positive lens L5a, a biconvex positive lens L5b, and a biconcave negative lens L5c. The lens includes a cemented lens and a biconvex positive lens L5d, and both lens surfaces of the biconvex positive lens L5a have a predetermined aspherical shape.

  The zoom lens having the image stabilization function according to the first exemplary embodiment has a large interval between the first lens group G1 and the second lens group G2 during zooming from the wide-angle end to the telephoto end, and the second lens group G2 and the third lens group G3. The distance from the lens group G3 is reduced, and the second lens group G2 is moved to the object side during focusing from infinity to a close object.

Subsequently, specification values of the zoom lens having the image stabilization function according to Example 1 are shown below.
Numerical example 1
Unit: mm
[Surface data]
Surface number rd nd vd
Object ∞ (d0)
1 200.0000 1.7500 1.84666 23.78
2 78.8290 8.1910 1.72916 54.67
3 998.8660 0.1500
4 58.4900 6.6480 1.72916 54.67
5 145.3560 (d5)
6 * 614.6130 0.1000 1.51840 52.10
7 137.7290 1.1000 1.88300 40.80
8 16.6280 7.3970
9 -37.2120 0.9500 1.72916 54.67
10 106.7260 0.1730
11 45.1210 4.5880 1.84666 23.78
12 -45.1210 1.0000
13 -28.5210 0.9000 1.72916 54.67
14 -84.3050 (d14)
15 (Aperture) ∞ 1.1500
16 76.3230 2.3540 1.72916 54.67
17 -578.5590 0.1500
18 31.8080 0.8000 2.00100 29.13
19 19.6780 5.4990 1.43700 95.10
20 236.4150 0.1500
21 56.9870 5.0320 1.49700 81.61
22 -38.7170 (d22)
23 -38.1790 2.3400 1.84666 23.78
24 -25.3210 0.9000 1.59171 66.86
25 * 93.4700 1.1920
26 29.0120 2.4500 1.90366 31.31
27 48.4830 2.3810
28 -63.5070 0.8000 1.84666 23.78
29 -62040.0000 (d29)
30 * 35.0758 7.2780 1.58673 60.99
31 * -25.4050 0.1500
32 302.6930 5.9710 1.62004 36.30
33 -20.5000 0.8000 1.90366 31.31
34 35.1520 2.0160
35 429.1600 2.3810 1.91082 35.25
36 -84.3980 (BF)
Image plane ∞

[Aspherical data]
6 faces 25 faces 30 faces 31 faces
K 0.00000 0.00000 0.00000 0.00000
A4 1.33980E-05 -4.03460E-07 -1.35780E-05 1.07760E-05
A6 -2.01690E-08 -1.39880E-08 -5.93500E-09 -4.71680E-10
A8 1.54090E-11 2.72550E-11 1.34960E-10 3.26740E-11
A10 2.13740E-14 -6.44750E-13 -2.90050E-13

[Various data]
Wide angle Medium telephoto Focal length 24.85 52.75 117.06
F number 4.06 4.00 4.07
Full angle of view 2ω 83.81 42.94 20.24
Image height Y 21.63 21.63 21.63
Total lens length 152.73 172.00 199.28

[Variable interval data]
Wide angle Medium telephoto
d5 3.5040 20.5000 45.4830
d14 24.2790 10.3840 2.4000
d22 2.0250 7.1730 5.3220
d29 7.5310 2.8030 0.7500
BF 38.6526 54.4039 68.5866

[Lens group data]
Group Start surface Focal length
G1 1 103.87
G2 6 -17.71
G3 15 32.09
G4 23 -53.24
G5 30 52.18
G4A 23 -54.42
G4B 26 1120.67

  FIG. 11 is a lens configuration diagram of a zoom lens having an image stabilization function according to Example 2 of the present invention. In order from the object side, the first lens group G1, the second lens group G2, the third lens group G3, the fourth lens group G4, and the fifth lens group G5 are included. The first lens group G1 has a positive refractive power as a whole. A cemented lens composed of two lenses, a negative meniscus lens L1a having a convex surface facing the object side and a biconvex positive lens L1b, and a positive meniscus lens L1c having a convex surface facing the object side. It is configured.

  The second lens group G2 has a negative refractive power as a whole, a negative meniscus lens L2a having a convex surface facing the object side, a biconcave negative lens L2b, a biconvex positive lens L2c, and an image. A negative meniscus lens L2d having a convex surface facing the side, and the object-side lens surface of the negative meniscus lens L2a and the image-side lens surface of the negative meniscus lens L2d have a predetermined aspherical shape.

  The third lens group G3 has a positive refractive power as a whole, and includes an aperture stop S, a biconvex positive lens L3a, a negative meniscus lens L3b having a convex surface facing the object side, and a biconvex positive lens. It consists of a cemented lens composed of two lenses L3c and a biconvex positive lens L3d.

  The fourth lens group G4 has a negative refractive power as a whole, and is composed of a cemented lens including two lenses, a positive meniscus lens L4a having a concave surface facing the object side and a biconcave negative lens L4b. A fourth lens group having a positive refractive power, composed of a cemented lens composed of a front lens group G4A having a negative refractive power, a biconvex positive lens L4c, and a biconcave negative lens L4d. It consists of a rear group G4B. The fourth lens unit front group G4A is moved in a direction substantially perpendicular to the optical axis to perform image stabilization.

  The fifth lens group G5 has a positive refractive power as a whole, and includes two lenses, a biconvex positive lens L5a, a positive meniscus lens L5b with a concave surface facing the object side, and a biconcave negative lens L5c. And a biconvex positive lens L5d. Both lens surfaces of the biconvex positive lens L5a have a predetermined aspherical shape.

  Further, in the zoom lens having the image stabilization function according to the second embodiment, the distance between the first lens group G1 and the second lens group G2 is large during zooming from the wide-angle end to the telephoto end, and the second lens group G2 and the third lens group G3. The distance from the lens group G3 is reduced, and the second lens group G2 is moved to the object side during focusing from infinity to a close object.

Subsequently, specification values of the zoom lens having the image stabilization function according to Example 2 are shown below.
Numerical example 2
Unit: mm
[Surface data]
Surface number rd nd vd
Object ∞ (d0)
1 220.6200 1.7500 1.84666 23.78
2 87.6840 8.4200 1.59349 67.00
3 -1001.5910 0.1500
4 58.2620 6.4000 1.77250 49.62
5 142.0050 (d5)
6 * 129.8850 1.2000 1.88300 40.80
7 15.6100 6.6390
8 -36.7260 0.9500 1.72916 54.67
9 111.2650 0.5910
10 45.9190 4.4240 1.84666 23.78
11 -45.9180 0.8760
12 -30.7960 1.1000 1.69350 53.20
13 * -161.6570 (d13)
14 (Aperture) ∞ 1.1500
15 39.1280 3.3460 1.43700 95.10
16 -1000.3210 2.0540
17 36.6610 1.0000 2.00100 29.13
18 19.9800 5.6760 1.59282 68.62
19 -203.6470 0.1930
20 81.4350 3.4070 1.59282 68.62
21 -81.4350 (d21)
22 -33.0220 2.7160 1.84666 23.78
23 -20.3720 0.8000 1.54814 45.82
24 84.8870 1.0390
25 26.6210 5.0510 1.60342 38.01
26 -75.2670 0.8140 1.74400 44.90
27 36.8840 (d27)
28 * 43.5380 6.0300 1.59201 67.02
29 * -30.3040 0.2060
30 -58.6150 2.6680 1.43700 95.10
31 -35.5860 0.9850 1.90366 31.31
32 48.4120 0.8390
33 82.7690 4.2080 1.77250 49.62
34 -63.7330 (BF)
Image plane ∞

[Aspherical data]
6 faces 13 faces 28 faces 29 faces
K 0.00000 0.00000 0.00000 0.00000
A4 5.91650E-06 -8.67000E-07 -1.14570E-05 7.29430E-06
A6 -1.11810E-08 1.60320E-09 -1.66350E-08 -1.48540E-08
A8 -7.85810E-12 -2.28310E-10 3.43440E-11 4.15830E-11
A10 4.32170E-14 1.10010E-12

[Various data]
Wide angle Medium telephoto Focal length 24.86 50.58 101.70
F number 4.06 4.11 4.07
Full angle of view 2ω 84.59 45.20 23.15
Image height Y 21.63 21.63 21.63
Total lens length 151.90 170.47 198.20

[Variable interval data]
Wide angle Medium telephoto
d5 3.3360 17.3520 43.1030
d13 22.2610 8.3040 2.2550
d21 2.8250 7.2730 9.4150
d27 9.3350 3.7400 1.8180
BF 39.4591 59.1232 66.9314

[Lens group data]
Group Start surface Focal length
G1 1 104.32
G2 6 -17.06
G3 14 30.17
G4 22 -62.58
G5 28 63.48
G4A 22 -58.25
G4B 25 416.90

  FIG. 21 is a lens configuration diagram of a zoom lens having an image stabilization function according to Example 3 of the present invention. In order from the object side, the first lens group G1, the second lens group G2, the third lens group G3, the fourth lens group G4, and the fifth lens group G5 are included. The first lens group G1 has a positive refractive power as a whole. A cemented lens composed of two lenses, a negative meniscus lens L1a having a convex surface facing the object side and a positive meniscus lens L1b having a convex surface facing the object side, and a positive meniscus having a convex surface facing the object side It consists of a lens L1c.

  The second lens group G2 has a negative refractive power as a whole, a negative meniscus lens L2a having a convex surface facing the object side, a biconcave negative lens L2b, a biconvex positive lens L2c, and an image. And a negative meniscus lens L2d having a convex surface directed to the side. The object-side lens surface of the negative meniscus lens L2a has a predetermined aspherical shape.

  The third lens group G3 has a positive refractive power as a whole, and is biconvex with an aperture stop S, a positive meniscus lens L3a with a convex surface facing the object side, a negative meniscus lens L3b with a convex surface facing the object side, and biconvex. It is composed of a cemented lens composed of two lenses, a positive lens L3c having a shape, and a positive lens L3d having a biconvex shape.

  The fourth lens group G4 has a negative refractive power as a whole, and is composed of a cemented lens including two lenses, a biconcave negative lens L4a and a positive meniscus lens L4b with a convex surface facing the object side. A fourth lens group G4A having a negative refractive power and a fourth lens group G4B composed of a positive meniscus lens L4c having a convex surface directed toward the object side, and are arranged on the object side of the biconcave negative lens L4a. The surface has a predetermined aspherical shape. The fourth lens unit front group G4A is moved in a direction substantially perpendicular to the optical axis to perform image stabilization.

  The fifth lens group G5 has a positive refractive power as a whole, and includes two lenses, a biconvex positive lens L5a, a positive meniscus lens L5b with a concave surface facing the object side, and a biconcave negative lens L5c. The both lens surfaces of the biconvex positive lens L5a have a predetermined aspherical shape.

  In the zoom lens having the image stabilization function according to the third exemplary embodiment, the distance between the first lens group G1 and the second lens group G2 is large during zooming from the wide-angle end to the telephoto end, and the second lens group G2 and the third lens group G3. The distance from the lens group G3 is reduced, and the second lens group G2 is moved to the object side during focusing from infinity to a close object.

Subsequently, specification values of the zoom lens having the image stabilization function according to Example 3 are shown below.
Numerical example 3
Unit: mm
[Surface data]
Surface number rd nd vd
Object ∞ (d0)
1 250.0000 1.5000 1.84666 23.78
2 82.1490 7.2060 1.77250 49.62
3 821.4110 0.1500
4 62.6140 5.3530 1.77250 49.62
5 163.3070 (d5)
6 * 104.7770 0.8500 1.85135 40.10
7 17.2890 8.0430
8 -43.6060 0.8500 1.72916 54.67
9 48.9640 0.4980
10 37.3030 6.2160 1.80518 25.46
11 -44.0640 0.9800
12 -29.2990 0.8500 1.72916 54.67
13 -115.9540 (d13)
14 (Aperture) ∞ 1.0000
15 35.0260 11.4840 1.49700 81.60
16 1849.0240 0.1500
17 36.8490 1.0000 2.00100 29.13
18 20.8950 5.6610 1.43700 95.10
19 -269.3320 0.1500
20 35.7980 3.9400 1.49700 81.60
21 -328.3160 (d21)
22 * -81.9170 1.0000 1.69350 53.20
23 34.0560 2.1420 1.92286 20.88
24 62.0600 2.4430
25 34.8170 2.2380 1.49700 81.60
26 62.1440 (d26)
27 * 61.5870 6.2190 1.80610 40.73
28 * -35.0890 0.1500
29 -88.8390 3.0740 1.49700 81.60
30 -40.9640 1.0000 1.80518 25.46
31 69.9990 (BF)
Image plane ∞

[Aspherical data]
6 faces 22 faces 27 faces 28 faces
K 0.00000 22.91277 0.00000 0.00000
A4 4.40520E-06 4.91366E-06 -6.90440E-06 6.34150E-06
A6 -5.31260E-11 2.10712E-08 -1.53580E-08 -1.30810E-08
A8 -1.99740E-11 -3.91921E-11 1.56770E-11 1.12020E-11
A10 4.52160E-14 2.89733E-13 3.78100E-14 5.34740E-14

[Various data]
Wide angle Medium telephoto Focal length 24.85 50.00 101.49
F number 2.83 3.38 4.13
Full angle of view 2ω 83.87 45.17 23.38
Image height Y 21.63 21.63 21.63
Total lens length 160.47 178.12 205.44

[Variable interval data]
Wide angle Medium telephoto
d5 3.3000 22.4870 39.5480
d13 25.7590 11.0340 1.3100
d21 2.5190 10.8400 15.4940
d26 14.5970 6.2770 1.6220
BF 40.1490 53.3326 73.3220

[Lens group data]
Group Start surface Focal length
G1 1 107.97
G2 6 -18.56
G3 14 35.34
G4 22 -98.86
G5 27 77.20
G4A 22 -59.99
G4B 25 155.09

  FIG. 31 is a lens configuration diagram of a zoom lens having an image stabilization function according to Example 4 of the present invention. In order from the object side, the first lens group G1, the second lens group G2, the third lens group G3, the fourth lens group G4, and the fifth lens group G5 are included. The first lens group G1 has a positive refractive power as a whole. A cemented lens composed of two lenses, a negative meniscus lens L1a having a convex surface facing the object side and a positive meniscus lens L1b having a convex surface facing the object side, and a positive meniscus having a convex surface facing the object side It consists of a lens L1c.

  The second lens group G2 has a negative refractive power as a whole, and has a negative meniscus lens L2a having a convex surface facing the object side, a biconcave negative lens L2b, a biconvex positive lens L2c, and an image side. And a negative meniscus lens L2d with a convex surface facing the lens surface. The object side lens surface of the negative meniscus lens L2a has a predetermined aspherical shape.

  The third lens group G3 has a positive refractive power as a whole, and includes an aperture stop S, a biconvex positive lens L3a, a negative meniscus lens L3b having a convex surface facing the object side, and a biconvex positive lens. It is comprised with the cemented lens which consists of two lenses with L3c.

  The fourth lens group G4 has a negative refractive power as a whole, and is composed of a cemented lens including two lenses, a positive meniscus lens L4a having a concave surface facing the object side and a biconcave negative lens L4b. A fourth lens group front group G4A having a negative refractive power, a positive meniscus lens L4c having a convex surface facing the object side, and a negative meniscus lens L4d having a convex surface facing the image side. The lens group rear group G4B is configured, and the image-side lens surface of the biconcave negative lens L4b has a predetermined aspherical shape. The fourth lens unit front group G4A is moved in a direction substantially perpendicular to the optical axis to perform image stabilization.

  The fifth lens group G5 has a positive refractive power as a whole, and is composed of two lenses, a biconvex positive lens L5a, a biconvex positive lens L5b, and a biconcave negative lens L5c. It is composed of a cemented lens and a positive meniscus lens L5d having a convex surface facing the object side. Both lens surfaces of the biconvex positive lens L5a have a predetermined aspherical shape.

  In the zoom lens having the image stabilization function according to the fourth exemplary embodiment, the distance between the first lens group G1 and the second lens group G2 is large during zooming from the wide-angle end to the telephoto end, and the second lens group G2 and the third lens group G3. The distance from the lens group G3 is reduced, and the second lens group G2 is moved to the object side during focusing from infinity to a close object.

Subsequently, specification values of the zoom lens having the image stabilization function according to Example 4 are shown below.
Numerical example 4
Unit: mm
[Surface data]
Surface number rd nd vd
Object ∞ (d0)
1 200.0000 1.7500 1.84666 23.78
2 81.5930 7.6400 1.72916 54.67
3 893.1800 0.1500
4 56.9300 5.8960 1.77250 49.62
5 114.0700 (d5)
6 * 116.5130 1.2000 1.83481 42.72
7 17.0000 7.6390
8 -39.0150 0.9500 1.77250 49.62
9 64.3750 1.8340
10 48.0960 4.8040 1.80518 25.46
11 -40.7930 0.9430
12 -26.4040 0.9000 1.77250 49.62
13 -61.3500 (d13)
14 (Aperture) ∞ 0.9700
15 47.3650 3.0380 1.49700 81.61
16 -196.9860 0.1500
17 28.3630 0.8000 2.00100 29.13
18 19.0480 6.6980 1.43700 95.10
19 -57.5460 (d19)
20 -55.5570 1.8400 1.84666 23.78
21 -39.9890 1.0000 1.58913 61.25
22 * 71.7080 1.7910
23 37.4570 3.4360 1.80610 33.27
24 561.0080 1.9160
25 -37.7840 0.8000 1.58144 40.89
26 -483.2370 (d26)
27 * 36.9380 6.8490 1.58313 59.46
28 * -25.3840 0.1500
29 88.1400 4.7190 1.49700 81.61
30 -27.7910 0.8000 1.80610 33.27
31 30.4420 1.6660
32 99.9860 2.0510 1.75520 27.53
33 8049.5770 (BF)
Image plane ∞

[Aspherical data]
6 faces 22 faces 27 faces 28 faces
K 0.00000 0.00000 0.00000 0.00000
A4 7.18990E-06 -2.42680E-06 -1.35860E-05 1.36000E-05
A6 -4.99010E-09 -1.82950E-09 8.58250E-09 -2.24320E-09
A8 -1.03400E-11 -1.92150E-11 -9.25420E-12
A10 5.93820E-14 -5.90440E-14

[Various data]
Wide angle Medium telephoto Focal length 24.53 50.54 103.51
F number 4.06 4.07 4.09
Full angle of view 2ω 84.70 45.20 23.12
Image height Y 21.63 21.63 21.63
Total lens length 147.52 168.19 195.53

[Variable interval data]
Wide angle Medium telephoto
d5 3.4080 20.5000 44.9140
d13 22.7480 9.0010 1.3100
d19 2.0500 8.8250 8.6570
d26 8.2820 2.3540 0.7000
BF 38.6549 55.1266 67.5706

[Lens group data]
Group Start surface Focal length
G1 1 110.80
G2 6 -18.67
G3 14 38.95
G4 20 -94.30
G5 27 53.62
G4A 20 -58.52
G4B 23 141.21

  In addition, a list of corresponding values of the conditional expressions in each of these examples is shown.

[Values for conditional expressions]
Conditional expression / Example 1 2 3 4
(1) 0.70 <f1 / fT <1.25 0.89 1.03 1.06 1.07
(2) -0.22 <f2 / fT <-0.10 -0.15 -0.17 -0.18 -0.18
(3) -0.80 <f4A / f4B <0.00 -0.05 -0.14 -0.39 -0.41
(4) 0.20 <f3 / fT <0.50 0.27 0.30 0.35 0.38
(5) 15.00 <f2 / βW345 <22.00 17.75 16.05 19.13 19.73

G1 1st lens group G2 2nd lens group G3 3rd lens group G4 4th lens group G4A 4th lens group front group G4B 4th lens group back group G5 5th lens group S Aperture stop d d line g g line CC Line ΔS Sagittal image plane ΔM Meridional image plane

Claims (4)

From the object side,
A first lens group G1 having a positive refractive power; a second lens group G2 having a negative refractive power; a third lens group G3 having an aperture stop S on the object side and having a positive refractive power; A fourth lens group G4 having a refractive power and a fifth lens group G5 having a positive refractive power;
The fourth lens group G4 is composed of a fourth lens group front group G4A having negative refractive power and a fourth lens group rear group G4B having positive refractive power in order from the object side.
During zooming from the wide-angle end to the telephoto end, the distance between the first lens group G1 and the second lens group G2 changes, and the distance between the second lens group G2 and the third lens group G3 decreases. The distance between the third lens group G3 and the fourth lens group G4 is increased, and the distance between the fourth lens group G4 and the fifth lens group G5 is decreased.
By moving the fourth lens group front group G4A in a direction substantially perpendicular to the optical axis, it is possible to correct image movement caused by camera shake or the like by moving the image in a direction perpendicular to the optical axis. And a zoom lens having an anti-vibration function characterized by satisfying the following conditional expression:

(1) 0.70 <f1 / fT <1.25
(2) -0.22 <f2 / fT <-0.10
(5) 15.00 <f2 / βW345 <22.00

f1: Focal length of the first lens group G1 f2: Focal length of the second lens group G2 fT: Focal length of the entire zoom lens system at the telephoto end
βW345: Composite magnification of the third lens group G3, the fourth lens group G4, and the fifth lens group G5 at the wide angle end 2. A zoom lens having an image stabilization function according to claim 1, wherein the zoom lens further satisfies the following conditional expression.

(3) -0.80 <f4A / f4B <0.00

f4A: focal length of the fourth lens group front group G4A f4B: focal length of the fourth lens group rear group G4B A zoom lens having an image stabilization function according to claim 1 or 2, further satisfying the following conditional expression:

(4) 0.20 <f3 / fT <0.50

f3: focal length of the third lens group G3 fT: focal length of the entire zoom lens system at the telephoto end A zoom lens system with a vibration reduction function according to any one of claims 1 to 3, by further moving the second lens group G2 from the image side to the object side along the optical axis, infinitely Zoom lens with anti-vibration function that focuses on objects from a short distance.

Images