JP2013050674A - Standard lens - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact, bright, and high-quality image capturing standard zoom lens with a variable magnification ratio of about 3, which features standard zooming with a wobbling function that is also applicable to video recording.SOLUTION: A zoom lens comprises a first lens group having negative refractive power, a second lens group having positive refractive power, a third lens group having positive refractive power, a fourth lens group having negative refractive power, and a fifth lens group having positive refractive power, located in order from the object side. The zoom lens changes magnification by varying the distance between each pair of lens group. When zooming from the wide angle end to the telephoto end, the distance between the first lens group and the second lens group is narrowed while the distance between the second lens group and the third lens group is varied, and the distance between the third lens group and the fourth lens group and the distance between the fourth lens group and the fifth lens group are both widened.

Description

  The present invention relates to a zoom lens, and particularly to a standard zoom lens having a small size and high image quality, which is most suitable for an interchangeable lens system.

  In recent years, interchangeable-lens digital cameras have become widespread, and high image quality, beautiful blurry beauty, and enjoyment of image expression by exchanging lenses are not possible with conventional so-called compact digital cameras. , Etc. have been recognized.

  These users often start by purchasing a set of body and standard zoom lenses. However, standard zoom lenses that are sold as a set are inexpensive and require certain things, so many F-numbers are about 3.5 to 5.6. For users who have learned the joy of photography, Many people want to take better photos and buy new interchangeable lenses. In particular, for users who long for high image quality and blur, and want to use a large-diameter interchangeable lens, if you want to express a photograph that takes advantage of the blur, a request for an interchangeable lens with an F number of 2.8 or 2.8-4 is required. There is.

As prior examples of the open F number of 2.8, there are Patent Document 1 and Patent Document 2. In either case, the F number is 2.8 over the entire zoom range. The former is a five-group zoom of negative refracting power, positive refracting power, negative refracting power, positive refracting power, and positive refracting power in order from the object side, and focuses on a part of the second lens group. The latter is a 6-group zoom of negative refracting power, positive refracting power, negative refracting power, positive refracting power, negative refracting power, and positive refracting power in order from the object side, and the fifth lens group focuses. However, both examples are large in size and poor in portability.
Examples of high-quality interchangeable lenses include Patent Document 3 and Patent Document 4. In each of the zoom lenses, a five-unit zoom of negative refracting power, positive refracting power, positive refracting power, negative refracting power, and positive refracting power is configured in order from the object side. For example, in Patent Document 3, the F number is 3.4 to 5.6. And big. In Patent Document 3, there is no mention of a focus method. However, if focusing is performed on a group having a small weight (for example, the second group or the fourth group), the variation in aberration at a short distance becomes large.
On the other hand, in Japanese Patent Application Laid-Open No. 2004-260688, although the correspondence with moving images is considered, a high zoom ratio of 2 or less cannot be obtained.

JP 2007-093976 A JP 2010-243636 A JP 2004-258644 A JP 2010-176096 A

  On the other hand, there are many products that can shoot moving images in recent digital cameras, and interchangeable lenses that support the moving image shooting function of the body are also required in interchangeable lens digital cameras.

  With conventional still image cameras, the objective was to cut off an instant shooting opportunity, so after deciding on the composition, it was only necessary to focus on the subject that was aimed at the moment of shooting, and there was a need for a function for that purpose. . Specifically, a so-called phase difference type autofocus (AF) function is employed, and the AF method has both speed and accuracy.

  However, in moving image shooting, with the exception of some professional video cameras, many consumer video cameras must always be kept in focus by operating AF. As a method therefor, a contrast AF method (so-called hill-climbing method) using an image sensor has been adopted. Further, in order to maintain the in-focus state, the change in contrast is measured by moving the focus lens always by a minute amount before and after the in-focus position (referred to as wobbling), and the in-focus state changes. If it is determined that the focus lens is appropriately moved, the focus lens is moved again to operate again. Since this wobbling function requires a very high speed operation according to the frame rate, the wobbling lens needs to be reduced in weight.

    In the present invention, a standard zoom lens having a zoom ratio of about 3 is provided with a standard zoom that is compact and bright, has high image quality, and that takes into account the wobbling function to cope with the moving image function.

  In order to solve the above-described problems and achieve the object, the zoom lens of the present invention includes, in order from the object side, a first lens group having a negative refractive power, a second lens group having a positive refractive power, and a third lens having a positive refractive power. In a zoom lens having a lens group, a fourth lens group having a negative refractive power, and a fifth lens group having a positive refractive power, and performing zooming by changing the interval of each group, when zooming from the wide-angle end to the telephoto end, The distance between the first lens group and the second lens group decreases, the distance between the second lens group and the third lens group changes, the distance between the third lens group and the fourth lens group increases, and the fourth lens group and the fifth lens The group spacing is characterized by an increase.

  In the zoom lens according to the present invention, the second lens group having a positive refractive power is provided between the first lens group having a negative refractive power having an image surface correction function and the third lens group having a positive refractive power having a zooming function. It is arranged. This second lens group has the effect of lowering the beam height of the peripheral light beam on the wide angle side and reducing the outer diameter of the first lens group. As a result, it is possible to reduce the filter diameter and contribute to the miniaturization of the lens. Further, when the F-number on the telephoto side is small, there is an effect of reducing the aperture diameter. As a result, the outer diameter of the lens frame around the stop can be reduced.

  Furthermore, in the zoom lens of the present invention, the zooming function is mainly borne by the third lens group. However, if the burden increases, the amount of movement of the third lens group increases, leading to an increase in size, or the third lens group. This increases the refractive power of the lens and undesirably unbalances aberration correction. Therefore, the zooming function is also functioned in the fourth lens group, and the third lens group and the fourth lens group are appropriately burdened.

The zoom lens according to the present invention preferably satisfies the following conditional expressions (1), (2), and (3).
1.2 <β _4t / β _4w <2.5 (1)
_{0.1 <(d 34t - d 34w} ) / f w <1.5 ··· (2)
_{0.4 <(d 45t - d 45w} ) / f w <3.2 ··· (3)
Where β _4t is the lateral magnification of the fourth lens group at the telephoto end, β _4w is the lateral magnification of the fourth lens group at the wide-angle end,
d _34w is the air gap between the third lens group and the fourth lens group at the wide angle end, d _34t is the air gap between the third lens group and the fourth lens group at the telephoto end, and d _45w is the air gap at the wide angle end. wherein the fourth lens group fifth lens group of the air gap, d _45t air gap of said fifth lens group and the fourth lens group at the telephoto end, the f _w is a focal length at the wide angle end.

  When the lower limit of the expression (1) is exceeded, the multiplication action of the fourth lens group becomes weak, the refractive power of the third lens group becomes too strong to ensure the zoom ratio, and the aberration correction balance is lost. Increasing the amount of movement of the three lenses increases the overall lens length. If the upper limit of the expression (1) is exceeded, the amount of movement of the fourth lens group becomes large or the refractive power becomes too strong, and the balance of aberration correction is lost, which is not preferable.

  When the lower limit of the expressions (2) and (3) is exceeded, the multiplication action of the fourth lens group becomes weak and the lens diameter of the fourth lens group becomes large. Exceeding the upper limits of the equations (2) and (3) is not preferable because it leads to an increase in the total lens length.

In addition, the zoom lens according to the present invention preferably satisfies the following conditional expression (4).
_{2.0 <f 2 / f w <} 13.0 ··· (4)
Here, f ₂ is the focal length of the second lens group.

  If the lower limit of the expression (4) is exceeded, the refractive power of the second lens group becomes too strong, and it becomes difficult to correct spherical aberration. If the upper limit of the expression (4) is exceeded, the effect of downsizing by the second lens group is weakened, and the outer diameter of the first lens group is increased, and the aperture diameter is also increased.

The zoom lens according to the present invention preferably satisfies the following conditional expressions (5) and (6).
3 < _ft / _fw ... (5)
1.0 <f _bw / f _w <1.9 (6)
However, f _t is the focal length at the telephoto end, the f _bw a back focus at the wide angle end, and are intended to be in the air.

  Equation (5) relates to the zoom ratio, and the zoom ratio of the optical system of the present invention is limited to a high zoom ratio of 3 or more. If the lower limit of the expression (6) is exceeded, the back focus becomes too short to satisfy the interchangeable lens system. Further, if the upper limit of the expression (6) is exceeded, the back focus becomes long and the total length of the lens is increased, which is not preferable.

In the zoom lens of the present invention, the first lens group includes a negative first lens, a negative second lens, and a positive third lens in order from the object side, and the fourth lens group includes at most three lenses. It is preferable that the lens includes the following lenses, and has at least a positive lens and a negative lens in order from the object side, and satisfies the following conditional expressions (7) and (8).
60 <ν ₁₂ (7)
_{5 <| ν 4p - ν 4n} | <25 ··· (8)
Where ν ₁₂ is the Abbe number of the negative second lens in the first lens group, ν _4p is the Abbe number of the positive lens in the fourth lens group, and ν _4n is the negative lens in the fourth lens group. Abbe number.

Expression (7) is a conditional expression for correcting axial chromatic aberration. In the zoom lens according to the present invention, the axial chromatic aberration is likely to be overcorrected at the intermediate focal length. Therefore, the correction of the axial chromatic aberration is suppressed to an appropriate range by suppressing the dispersion of the negative second lens.

Expression (8) is an expression for suppressing correction of chromatic aberration within an appropriate range.
If the lower limit of equation (8) is exceeded, the effect of color correction is lost. If the upper limit of equation (8) is exceeded, the correction balance with other groups will be lost.

  In the zoom lens according to the present invention, it is preferable that the fourth lens group moves when focusing from an infinite object point to a close object point.

  By using the fourth lens group for focusing adjustment, the aberration variation is small and the focus mechanism can be made small, and the entire system can be made compact.

The zoom lens according to the present invention preferably satisfies the following conditional expression (9).
1.0 <| f ₄ / f _w | <7.0 (9)
Here, f ₄ is the focal length of the fourth lens group.

  If the lower limit of equation (9) is exceeded, the refractive power of the fourth lens group becomes too strong, and sufficient aberration correction cannot be performed with a small number of lenses. If the upper limit of the expression (9) is exceeded, the refractive power of the fourth lens group becomes too weak, and the amount of movement becomes large, which is not preferable. Also, aberration fluctuations increase, which is not preferable.

  The zoom lens according to the present invention includes, in order from the object side, a first lens unit having a negative refractive power, a second lens group having a positive refractive power, a third lens group having a positive refractive power, a fourth lens group having a negative refractive power, and a positive lens unit. In a zoom lens that has a fifth lens unit with refractive power and performs zooming by changing the distance between each group, the fourth group and the fifth group move independently when focusing from an infinite object point to the closest object point. It is preferable to adopt a configuration to do so.

  Since the focus group is required to be light in weight, the second lens group and the fifth lens group can be focused in the present invention, but it can be said that the fourth lens group is preferable because the aberration variation is small. However, in the focus by the fourth lens group, the fluctuation of the curvature of field on the wide angle side is large, and if the F number at the wide angle end is about 4, it can be said that it is within the depth and there is no problem, but the F number is 2 Since it will exceed the depth at 8 class, it is difficult to focus with the fourth lens unit alone.

  Therefore, in order to correct the fluctuation of the field curvature in the lens having a small F number, it is preferable to move the fifth lens group simultaneously with the movement of the fourth lens group. At this time, the fourth lens group moves to the image side in the entire zoom range, but the fifth lens group moves to the image side on the wide angle side, moves to the object side on the telephoto side, and stops at an intermediate focal length on the way. Move so that there is a place to do. As a result, it is possible to correct the variation in field curvature from the infinity to the close range over the entire zoom range.

  In addition, it is possible to use the fourth lens group as the focus group and fix the fifth lens group during zooming, which is advantageous in simplifying the lens frame structure. However, in the present invention, since the exit pupil position is farther on the telephoto side, the lens diameter of the fifth lens group is determined by the light beam at the telephoto end. Therefore, in zooming from the wide-angle end to the telephoto end, moving the fifth lens unit to the object side is advantageous in downsizing because the lens diameter of the fifth lens unit can be reduced.

In addition, the zoom lens according to the present invention preferably satisfies the following conditional expression (10).
0.4 <△ _4w / △ _5w <2.0 (10)
However, Δ _4w is the focus movement amount of the fourth lens group at the wide-angle end, and Δ _5w is the focus movement amount of the fifth lens group at the wide-angle end, both of which are positive signs for movement in the optical axis direction.

  If the amount of movement of the fifth lens unit increases beyond the lower limit of the expression (10), the curvature of field near the wide-angle end becomes too undercorrected. On the other hand, if the amount of movement of the fifth lens group is small beyond the upper limit of the expression (10), the curvature of field remains insufficiently overcorrected.

  Further, it is preferable that the above conditional expressions are further as follows. Only the upper limit value or only the lower limit value of each conditional expression may be used as the new upper limit value and lower limit value. By doing in this way, the effect demonstrated by each conditional expression can be acquired more effectively.

Moreover, it becomes a more preferable structure by changing a conditional expression as follows.
1.3 <β _4t / β _4w <1.8 (1) ′
_{0.3 <(d 34t - d 34w} ) / f w <1.0 ··· (2) '
_{1.0 <(d 45t - d 45w} ) / f w <2.3 ··· (3) '
_{5.0 <f 2 / f w <} 10.0 ··· (4) '
3 < _ft / _fw ... (5) '
1.3 <f _bw / f _w <1.7 (6) ′
_{70 <ν 12 ··· (7)} '
_{10 <| ν 4p - ν 4n} | <20 ··· (8) '
2.4 <| f ₄ / f _w | <6.1 (9) ′
0.7 <△ _4w / △ _5w <2.0 (10) '

  According to the present invention, a standard zoom lens having a zoom ratio of about 3 can provide a standard zoom that is compact and bright, has high image quality, and that also takes into account the wobbling function in order to support the moving image function.

FIG. 2 is a lens cross-sectional view at a wide angle end (a), an intermediate state (b), and a telephoto end (c) when focusing on an object point at infinity according to the first embodiment relating to the zoom lens of the present invention. FIG. 2 is a lens cross-sectional view at a wide angle end (a), an intermediate state (b), and a telephoto end (c) when focusing on a close object (0.35 m) object point according to the first exemplary embodiment of the zoom lens of the present invention. FIG. 6 is an aberration diagram for Example 1 upon focusing on an object point at infinity. FIG. 6 is an aberration diagram for Example 1 upon focusing on a close object point (0.35 m). FIG. 6 is a lens cross-sectional view at a wide-angle end (a), an intermediate state (b), and a telephoto end (c) when focusing on an object point at infinity according to a second embodiment of the zoom lens of the present invention. FIG. 6 is a lens cross-sectional view at a wide-angle end (a), an intermediate state (b), and a telephoto end (c) when focusing on a close object (0.35 m) object point of Example 2 relating to the zoom lens of the present invention. FIG. 6 is an aberration diagram for Example 2 upon focusing on an object point at infinity. FIG. 6 is an aberration diagram for Example 2 upon focusing on a close object point (0.35 m). FIG. 6 is a lens cross-sectional view at a wide-angle end (a), an intermediate state (b), and a telephoto end (c) when focusing on an object point at infinity according to a third exemplary embodiment related to the zoom lens according to the present invention. FIG. 6 is a lens cross-sectional view at a wide-angle end (a), an intermediate state (b), and a telephoto end (c) when focusing on a close-up (0.35 m) object point in Example 3 relating to the zoom lens of the present invention. FIG. 10 is an aberration diagram for Example 3 upon focusing on an object point at infinity. FIG. 10 is an aberration diagram for Example 3 upon focusing on a close object point (0.35 m). FIG. 6 is a lens cross-sectional view at a wide-angle end (a), an intermediate state (b), and a telephoto end (c) when focusing on an object point at infinity according to Example 4 relating to the zoom lens of the present invention. FIG. 6 is a lens cross-sectional view at a wide-angle end (a), an intermediate state (b), and a telephoto end (c) when focusing on a close object (0.35 m) object point in Example 4 relating to the zoom lens of the present invention. FIG. 10 is an aberration diagram for Example 4 upon focusing on an object point at infinity. FIG. 10 is an aberration diagram for Example 4 upon focusing on a close object point (0.35 m). 6 is a lens cross-sectional view at a wide-angle end (a), an intermediate state (b), and a telephoto end (c) when focusing on an object point at infinity according to a fifth embodiment of the zoom lens of the present invention. FIG. FIG. 6 is a lens cross-sectional view at a wide-angle end (a), an intermediate state (b), and a telephoto end (c) when focusing on a close object (0.35 m) object point according to a fifth exemplary embodiment of the zoom lens according to the present invention. FIG. 10 is an aberration diagram for Example 5 upon focusing on an object point at infinity. FIG. 10 is an aberration diagram for Example 5 upon focusing on a close object point (0.35 m). FIG. 10 is a lens cross-sectional view at a wide angle end (a), an intermediate state (b), and a telephoto end (c) when focusing on an object point at infinity according to a sixth embodiment of the zoom lens of the present invention. FIG. 10 is a lens cross-sectional view at a wide angle end (a), an intermediate state (b), and a telephoto end (c) when focusing on a close object (0.35 m) object point in Example 6 relating to the zoom lens of the present invention. FIG. 10 is an aberration diagram for Example 6 upon focusing on an object point at infinity. FIG. 11 is an aberration diagram for Example 6 upon focusing on a close object point (0.35 m). FIG. 10 is a lens cross-sectional view at a wide-angle end (a), an intermediate state (b), and a telephoto end (c) when focusing on an object point at infinity according to Example 7 relating to the zoom lens of the present invention. FIG. 10 is a lens cross-sectional view at a wide-angle end (a), an intermediate state (b), and a telephoto end (c) when focusing on a close object (0.35 m) object point in Example 7 relating to the zoom lens of the present invention. FIG. 10 is an aberration diagram for Example 7 upon focusing on an object point at infinity. FIG. 10 is an aberration diagram for Example 7 upon focusing on a close object point (0.35 m). FIG. 10 is a lens cross-sectional view at a wide angle end (a), an intermediate state (b), and a telephoto end (c) when focusing on an object point at infinity according to an eighth embodiment relating to the zoom lens of the present invention. FIG. 10 is a lens cross-sectional view at a wide-angle end (a), an intermediate state (b), and a telephoto end (c) when focusing on a close object (0.35 m) object point in Example 8 relating to the zoom lens of the present invention. FIG. 10 is an aberration diagram for Example 8 upon focusing on an object point at infinity. FIG. 10 is an aberration diagram for Example 8 upon focusing on a close object point (0.35 m). FIG. 10 is a lens cross-sectional view at a wide-angle end (a), an intermediate state (b), and a telephoto end (c) when focusing on an object point at infinity according to Example 9 relating to the zoom lens of the present invention. 10 is a lens cross-sectional view at a wide-angle end (a), an intermediate state (b), and a telephoto end (c) when focusing on a close-up (0.35 m) object point in Example 9 relating to the zoom lens of the present invention. FIG. FIG. 10 is an aberration diagram for Example 9 upon focusing on an object point at infinity. FIG. 10 is an aberration diagram for Example 9 upon focusing at a close object point (0.35 m).

  The effect by the structure of the zoom lens and imaging device of this embodiment is demonstrated. In addition, this invention is not limited by this embodiment. That is, in describing the embodiment, a lot of specific details are included for the purpose of illustration, but various variations and modifications may be added to these details without exceeding the scope of the present invention. Accordingly, the exemplary embodiments of the present invention described below are set forth without loss of generality or limitation to the claimed invention.

Examples 1 to 9 of the zoom lens according to the present embodiment will be described below. The lens cross-sectional views of the wide-angle end (a), the intermediate focal length state (b), and the telephoto end (c) when focusing on an object point at infinity in Examples 1 to 9 are shown in FIGS. 1, 5, 9, and 13, respectively. 17, FIG. 21, FIG. 25, FIG. 29, FIG.
FIGS. 2, 6, and 6 show lens cross-sectional views of the wide-angle end (a), the intermediate focal length state (b), and the telephoto end (c) when focusing on an object point in close proximity (0.35 m) in Examples 1 to 9, respectively. 10, 14, 18, 22, 26, 30, and 34. 1, 5, 9, 13, 17, 21, 25, 29, 33, 2, 6, 10, 14, 18, 18, 22, 26, and 30. 34, the first lens group is G1, the second lens group is G2, the brightness (aperture) stop is S, the third lens group is G3, the fourth lens group is G4, the fifth lens group is G5, and the electron The parallel plate of the cover glass of the image sensor is indicated by C, and the image plane is indicated by I. In addition, you may give the multilayer film for a wavelength range restriction | limiting to the surface of the cover glass C. FIG. Further, the cover glass C may have a low-pass filter action.

  All of the numerical data is data in a state where an object at infinity is focused. The unit of length of each numerical value is mm, and the unit of angle is ° (degree). Further, the zoom data are values at the wide-angle end, the intermediate focal length state, and the telephoto end. Further, the positive / negative of the refractive power is based on the paraxial radius of curvature.

  Further, in order to cut unnecessary light such as ghost and flare, a flare stop other than the brightness stop may be arranged. The flare stop is on the object side of the first lens group, between the first lens group and the second lens group, between the second lens group and the third lens group, between the third lens group and the fourth lens group, You may arrange | position in any place between a 5th lens group and a 5th lens group and an image surface. The frame member may be configured to cut flare rays, or another member may be configured. Also, it may be printed directly on the optical system, painted, or bonded with a seal. The shape may be any shape such as a circle, an ellipse, a rectangle, a polygon, or a range surrounded by a function curve. Further, not only harmful light beams but also light beams such as coma flare around the screen may be cut.

  Further, each lens may be provided with an antireflection coating to reduce ghosts and flares. If the antireflection coating is a multi-coat, ghosts and flares can be effectively reduced. In order to prevent the occurrence of ghosts and flares, an antireflection coating is generally applied to the air contact surface of the lens. An infrared cut coat may be applied to the lens surface or the surface of the cover glass.

  On the other hand, at the cemented surface of the cemented lens, the refractive index of the adhesive is sufficiently higher than the refractive index of air. For this reason, the reflectance at the joint surface is often the same as or lower than that of the single layer coat. For this reason, it is rare to apply an antireflection coating to the cemented surface of the cemented lens. However, ghosts and flares can be further reduced by applying an antireflection coating to the joint surfaces. As a result, a better image can be obtained.

  In particular, a high refractive index glass material that has recently become widespread has a high aberration correction effect. For this reason, high refractive index glass materials are increasingly used in camera optical systems. However, when a high refractive index glass material is used as a cemented lens, reflection on the cemented surface cannot be ignored. In such a case, it is particularly effective to provide an antireflection coating on the joint surface. The effective usage of the bonding surface coat is disclosed in Japanese Patent Laid-Open Nos. 2-27301, 2001-324676, 2005-92115, and US Pat. No. 7,116,482. ing.

The zoom lenses of these patent documents are front-end zoom lenses, and describe the cemented lens surface coating in the first lens group. The cemented lens surface in the first lens unit having a positive refractive power according to the present embodiment may be implemented as disclosed in these documents. As the coating material to be used, Ta ₂ O ₅ , TiO ₂ , Nb ₂ O ₅ , ZrO ₂ , HfO ₂ , CeO, which have a relatively high refractive index, depending on the refractive index of the base lens and the refractive index of the adhesive. _{2, SnO 2, in 2 O} 3, ZnO, Y 2 O 3 coating material such as a relatively low refractive index of MgF _2, SiO _2, coating materials such as Al ₂ O _3, and appropriately selected, phase condition The film thickness may be set so as to satisfy the above.

  As a matter of course, the coating on the bonding surface may be a multi-coat as in the case of the coating on the air contact surface of the lens. By appropriately combining two or more layers of coating materials and film thicknesses, it becomes possible to further reduce the reflectance and control the spectral characteristics and angular characteristics of the reflectance. Needless to say, it is effective to coat the cemented surfaces other than the first lens group based on the same concept.

  As shown in FIG. 1, the zoom lens of Embodiment 1 includes a first lens group G1 having a negative refractive power, a second lens group G2 having a positive refractive power, and an aperture stop S in order from the object side. The third lens group G3 has a positive refractive power, the fourth lens group G4 has a negative refractive power, and the fifth lens group G5 has a positive refractive power.

At the time of zooming from the wide angle end to the telephoto end, the first lens group G1 moves to the image side and then moves to the object side. The second lens group G2 moves to the image side and then moves to the object side. The third lens group G3 moves to the object side. The fourth lens group G4 moves to the object side. The fifth lens group G5 moves to the image side after moving to the object side. Therefore, the distance between the lens groups is such that the distance between the first lens group G1 and the second lens group G2 changes, the distance between the second lens group G2 and the third lens group G3 changes, and the third lens group G3 The distance between the fourth lens group G4 changes and the distance between the fourth lens group G4 and the fifth lens group G5 changes.

  In order from the object side, the first lens group G1 includes a negative meniscus lens having a convex surface directed toward the object side, a biconcave negative lens, and a positive meniscus lens having a convex surface directed toward the object side. The second lens group G2 includes a biconvex positive lens and a cemented lens of a negative meniscus lens having a concave surface directed toward the object side. The third lens group G3 includes a positive meniscus lens having a convex surface directed toward the object side, an aperture stop, a positive meniscus lens having a convex surface directed toward the object side, a biconvex positive lens, a biconcave negative lens, and a biconvex positive lens. It consists of a lens. The fourth lens group G4 is composed of a cemented lens made up of a biconvex positive lens and a biconcave negative lens. The fifth lens group G5 is composed of a biconvex positive lens.

The aspheric surface includes both surfaces of a negative meniscus lens having a convex surface facing the object side of the first lens group, an object side surface of a positive meniscus lens having a convex surface facing the object side closest to the object side of the third lens group, The three lens groups are used on five surfaces including both surfaces of a biconvex positive lens existing closest to the image plane.
Note that the fourth lens group G4 and the fifth lens group G5 move independently of the focus lens, and the wobbling lens is the fourth lens group G4.

  As shown in FIG. 5, the zoom lens of Example 2 includes a first lens group G1 having a negative refractive power, a second lens group G2 having a positive refractive power, and an aperture stop S in order from the object side. The third lens group G3 has a positive refractive power, the fourth lens group G4 has a negative refractive power, and the fifth lens group G5 has a positive refractive power.

At the time of zooming from the wide angle end to the telephoto end, the first lens group G1 moves to the image side and then moves to the object side. The second lens group G2 moves to the image side and then moves to the object side. The third lens group G3 moves to the object side. The fourth lens group G4 moves to the object side. The fifth lens group G5 moves to the image side after moving to the object side. Therefore, the distance between the lens groups is such that the distance between the first lens group G1 and the second lens group G2 changes, the distance between the second lens group G2 and the third lens group G3 changes, and the third lens group G3 The distance between the fourth lens group G4 changes and the distance between the fourth lens group G4 and the fifth lens group G5 changes.

  In order from the object side, the first lens group G1 includes a negative meniscus lens having a convex surface directed toward the object side, a biconcave negative lens, and a positive meniscus lens having a convex surface directed toward the object side. The second lens group G2 includes a biconvex positive lens, a cemented lens of a positive meniscus lens having a concave surface facing the object side, and a negative meniscus lens having a concave surface facing the object side. The third lens group G3 includes a biconvex positive lens, an aperture stop, a biconvex positive lens, a biconvex positive lens, a biconcave negative lens, and a biconvex positive lens. The fourth lens group G4 includes a negative meniscus lens having a convex surface directed toward the object side, a positive meniscus lens having a convex surface directed toward the object side, and a cemented lens of a negative meniscus lens having a convex surface directed toward the object side. The fifth lens group G5 is composed of a biconvex positive lens.

The aspherical surface includes both surfaces of a negative meniscus lens having a convex surface facing the object side of the first lens group, the object side surface of the biconvex positive lens existing closest to the object side of the third lens group, and the most image of the third lens group. It is used for 5 surfaces including both surfaces of a biconvex positive lens existing on the surface side.
Note that the fourth lens group G4 and the fifth lens group G5 move independently of the focus lens, and the wobbling lens is the fourth lens group G4.

  The zoom lens of Example 3 includes a first lens group G1 having a negative refractive power, a second lens group G2 having a positive refractive power, and an aperture stop S in order from the object side, as shown in FIG. The third lens group G3 has a positive refractive power, the fourth lens group G4 has a negative refractive power, and the fifth lens group G5 has a positive refractive power.

  At the time of zooming from the wide angle end to the telephoto end, the first lens group G1 moves to the image side and then moves to the object side. The second lens group G2 moves to the object side. The third lens group G3 moves to the object side. The fourth lens group G4 moves to the object side. The fifth lens group G5 moves to the object side. Therefore, the distance between the lens groups is such that the distance between the first lens group G1 and the second lens group G2 changes, the distance between the second lens group G2 and the third lens group G3 changes, and the third lens group G3 The distance between the fourth lens group G4 changes and the distance between the fourth lens group G4 and the fifth lens group G5 changes.

  In order from the object side, the first lens group G1 includes a negative meniscus lens having a convex surface directed toward the object side, a biconcave negative lens, and a positive meniscus lens having a convex surface directed toward the object side. The second lens group G2 includes a positive flat lens having a convex surface facing the object side, a positive meniscus lens having a concave surface facing the object side, and a negative meniscus lens having a concave surface facing the object side. The third lens group G3 includes an aperture stop, a positive meniscus lens having a concave surface directed toward the object side, a cemented lens of a positive meniscus lens having a concave surface directed toward the object side and a biconcave negative lens, a biconvex positive lens, It consists of a concave negative lens, a biconvex positive lens, and a biconvex positive lens. The fourth lens group G4 is composed of a negative meniscus lens having a convex surface directed toward the object side and a cemented lens of a positive meniscus lens having a convex surface directed toward the object side. The fifth lens group G5 is composed of a biconvex positive lens.

The aspheric surface includes both surfaces of a negative meniscus lens having a convex surface facing the object side of the first lens group, both surfaces of a positive meniscus lens having a concave surface facing the object side closest to the object side of the third lens group, It is used for five surfaces, that is, the object side surface of a biconvex positive lens present on the most image side of the lens group.
Note that the fourth lens group G4 and the fifth lens group G5 move independently of the focus lens, and the wobbling lens is the fourth lens group G4.

  The zoom lens of Example 4 includes a first lens group G1 having a negative refractive power, a second lens group G2 having a positive refractive power, and an aperture stop S in order from the object side, as shown in FIG. The third lens group G3 has a positive refractive power, the fourth lens group G4 has a negative refractive power, and the fifth lens group G5 has a positive refractive power.

  At the time of zooming from the wide angle end to the telephoto end, the first lens group G1 moves to the image side and then moves to the object side. The second lens group G2 moves to the object side. The third lens group G3 moves to the object side. The fourth lens group G4 moves to the object side. The fifth lens group G5 moves to the object side. Therefore, the distance between the lens groups is such that the distance between the first lens group G1 and the second lens group G2 changes, the distance between the second lens group G2 and the third lens group G3 changes, and the third lens group G3 The distance between the fourth lens group G4 changes and the distance between the fourth lens group G4 and the fifth lens group G5 changes.

  In order from the object side, the first lens group G1 includes a negative meniscus lens having a convex surface directed toward the object side, a biconcave negative lens, and a positive meniscus lens having a convex surface directed toward the object side. The second lens group G2 includes a biconvex positive lens, a biconvex positive lens, and a biconcave negative lens. The third lens group G3 includes an aperture stop, a biconvex positive lens, a biconcave negative lens, a biconvex positive lens, a cemented lens of a biconvex positive lens and a biconcave negative lens, and a biconvex positive lens. . The fourth lens group G4 is composed of a negative meniscus lens having a convex surface directed toward the object side and a cemented lens of a positive meniscus lens having a convex surface directed toward the object side. The fifth lens group G5 is composed of a biconvex positive lens.

The aspherical surface includes both surfaces of a negative meniscus lens having a convex surface facing the object side of the first lens group, both surfaces of the second biconvex positive lens from the object side of the second lens group, and the object surface of the third lens group. When viewed from the side, it is used for six surfaces on both sides of a biconvex positive lens disposed next to a biconvex positive lens and a biconcave negative lens.
Note that the fourth lens group G4 and the fifth lens group G5 move independently of the focus lens, and the wobbling lens is the fourth lens group G4.

  The zoom lens of Example 5 includes a first lens group G1 having a negative refractive power, a second lens group G2 having a positive refractive power, and an aperture stop S in order from the object side, as shown in FIG. The third lens group G3 has a positive refractive power, the fourth lens group G4 has a negative refractive power, and the fifth lens group G5 has a positive refractive power.

  At the time of zooming from the wide angle end to the telephoto end, the first lens group G1 moves to the image side and then moves to the object side. The second lens group G2 moves to the object side. The third lens group G3 moves to the object side. The fourth lens group G4 moves to the object side. The fifth lens group G5 moves to the object side. Therefore, the distance between the lens groups is such that the distance between the first lens group G1 and the second lens group G2 changes, the distance between the second lens group G2 and the third lens group G3 changes, and the third lens group G3 The distance between the fourth lens group G4 changes and the distance between the fourth lens group G4 and the fifth lens group G5 changes.

  In order from the object side, the first lens group G1 includes a negative meniscus lens having a convex surface directed toward the object side, a biconcave negative lens, and a positive meniscus lens having a convex surface directed toward the object side. The second lens group G2 includes a biconvex positive lens and a biconcave negative lens. The third lens group G3 includes a biconvex positive lens, an aperture stop, a biconcave negative lens, a biconvex positive lens, a cemented lens of a biconvex positive lens and a negative meniscus lens having a concave surface facing the object side, Consists of a convex positive lens. The fourth lens group G4 is composed of a cemented lens made up of a biconvex positive lens and a biconcave negative lens. The fifth lens group G5 is composed of a biconvex positive lens.

The aspherical surface includes both surfaces of a negative meniscus lens having a convex surface facing the object side of the first lens group, both surfaces of a biconvex positive lens existing closest to the object side of the second lens group, and the object surface side of the third lens group. From the perspective, the biconvex positive lens and the biconcave negative lens are used next to the biconvex positive lens on both sides.
Note that the fourth lens group G4 and the fifth lens group G5 move independently of the focus lens, and the wobbling lens is the fourth lens group G4.

  The zoom lens of Embodiment 6 includes a first lens group G1 having a negative refractive power, a second lens group G2 having a positive refractive power, and an aperture stop S in order from the object side, as shown in FIG. The third lens group G3 has a positive refractive power, the fourth lens group G4 has a negative refractive power, and the fifth lens group G5 has a positive refractive power.

  At the time of zooming from the wide angle end to the telephoto end, the first lens group G1 moves to the image side and then moves to the object side. The second lens group G2 moves to the object side. The third lens group G3 moves to the object side. The fourth lens group G4 moves to the object side. The fifth lens group G5 moves to the object side. Therefore, the distance between the lens groups is such that the distance between the first lens group G1 and the second lens group G2 changes, the distance between the second lens group G2 and the third lens group G3 changes, and the third lens group G3 The distance between the fourth lens group G4 changes and the distance between the fourth lens group G4 and the fifth lens group G5 changes.

  In order from the object side, the first lens group G1 includes a negative meniscus lens having a convex surface directed toward the object side, a biconcave negative lens, and a positive meniscus lens having a convex surface directed toward the object side. The second lens group G2 includes a biconvex positive lens and a negative meniscus lens having a concave surface directed toward the object side. The third lens group G3 includes a biconvex positive lens, an aperture stop, a biconcave negative lens, a biconvex positive lens, and a biconvex positive lens. The fourth lens group G4 is composed of a cemented lens made up of a biconvex positive lens and a biconcave negative lens. The fifth lens group G5 is composed of a biconvex positive lens.

The aspherical surface includes both surfaces of a negative meniscus lens having a convex surface facing the object side of the first lens group, both surfaces of a biconvex positive lens existing closest to the object side of the second lens group, and the object surface side of the third lens group. From the perspective, the biconvex positive lens and the biconcave negative lens are used next to the biconvex positive lens on both sides.
The focus lens and the wobbling lens are in the fourth lens group G4.

  As shown in FIG. 25, the zoom lens according to the seventh embodiment includes a first lens group G1 having a negative refractive power, a second lens group G2 having a positive refractive power, and an aperture stop S in order from the object side. The third lens group G3 has a positive refractive power, the fourth lens group G4 has a negative refractive power, and the fifth lens group G5 has a positive refractive power.

  At the time of zooming from the wide angle end to the telephoto end, the first lens group G1 moves to the image side and then moves to the object side. The second lens group G2 moves to the object side. The third lens group G3 moves to the object side. The fourth lens group G4 moves to the object side. The fifth lens group G5 moves to the object side. Therefore, the distance between the lens groups is such that the distance between the first lens group G1 and the second lens group G2 changes, the distance between the second lens group G2 and the third lens group G3 changes, and the third lens group G3 The distance between the fourth lens group G4 changes and the distance between the fourth lens group G4 and the fifth lens group G5 changes.

  In order from the object side, the first lens group G1 includes a negative meniscus lens having a convex surface directed toward the object side, a negative meniscus lens having a convex surface directed toward the object side, and a positive meniscus lens having a convex surface directed toward the object side. The second lens group G2 includes a biconvex positive lens and a negative meniscus lens having a concave surface directed toward the object side. The third lens group G3 includes a positive meniscus lens having a convex surface directed toward the object side, an aperture stop, a biconcave negative lens, a biconvex positive lens, and a biconvex positive lens. The fourth lens group G4 is composed of a biconcave negative lens. The fifth lens group G5 is composed of a biconvex positive lens.

The aspherical surface includes both surfaces of a negative meniscus lens having a convex surface facing the object side of the first lens group, both surfaces of a biconvex positive lens existing closest to the object side of the second lens group, and the object surface side of the third lens group. From the perspective, the biconvex positive lens and the biconcave negative lens are used next to the biconvex positive lens on both sides.
The focus lens is the fifth lens group G5, and the wobbling lens is the fourth lens group G4.

  As shown in FIG. 29, the zoom lens according to the eighth embodiment includes a first lens group G1 having a negative refractive power, a second lens group G2 having a positive refractive power, and an aperture stop S in order from the object side. The third lens group G3 has a positive refractive power, the fourth lens group G4 has a negative refractive power, and the fifth lens group G5 has a positive refractive power.

  At the time of zooming from the wide angle end to the telephoto end, the first lens group G1 moves to the image side and then moves to the object side. The second lens group G2 moves to the object side. The third lens group G3 moves to the object side. The fourth lens group G4 moves to the object side. The fifth lens group G5 moves to the object side. Therefore, the distance between the lens groups is such that the distance between the first lens group G1 and the second lens group G2 changes, the distance between the second lens group G2 and the third lens group G3 changes, and the third lens group G3 The distance between the fourth lens group G4 changes and the distance between the fourth lens group G4 and the fifth lens group G5 changes.

  In order from the object side, the first lens group G1 includes a negative meniscus lens having a convex surface directed toward the object side, a negative meniscus lens having a convex surface directed toward the object side, and a positive meniscus lens having a convex surface directed toward the object side. The second lens group G2 includes a biconvex positive lens and a negative meniscus lens having a convex surface directed toward the object side. The third lens group G3 includes a positive meniscus lens having a convex surface directed toward the object side, an aperture stop, a biconcave negative lens, a biconvex positive lens, a negative meniscus lens having a convex surface directed toward the object side, and a biconvex positive lens. It consists of a cemented lens. The fourth lens group G4 is composed of a negative meniscus lens having a concave surface directed toward the object side. The fifth lens group G5 is composed of a biconvex positive lens.

The aspherical surface includes both surfaces of a negative meniscus lens having a convex surface facing the object side of the first lens group, the object side surface of a biconvex positive lens existing closest to the object side of the second lens group, and the most object of the third lens group. It is used on the six sides of the object side surface of a positive meniscus lens having a convex surface facing the object side existing on the side, and both surfaces of a biconvex positive lens disposed next to the subsequent biconcave negative lens.
The focus lens is the second lens group G2, and the wobbling lens is the fourth lens group G4.

  The zoom lens of Example 9 includes a first lens group G1 having a negative refractive power, a second lens group G2 having a positive refractive power, and an aperture stop S in order from the object side, as shown in FIG. The third lens group G3 has a positive refractive power, the fourth lens group G4 has a negative refractive power, and the fifth lens group G5 has a positive refractive power.

  At the time of zooming from the wide angle end to the telephoto end, the first lens group G1 moves to the image side and then moves to the object side. The second lens group G2 moves to the object side. The third lens group G3 moves to the object side. The fourth lens group G4 moves to the object side. The fifth lens group G5 moves to the object side. Therefore, the distance between the lens groups is such that the distance between the first lens group G1 and the second lens group G2 changes, the distance between the second lens group G2 and the third lens group G3 changes, and the third lens group G3 The distance between the fourth lens group G4 changes and the distance between the fourth lens group G4 and the fifth lens group G5 changes.

  In order from the object side, the first lens group G1 includes a negative meniscus lens having a convex surface directed toward the object side, a negative meniscus lens having a convex surface directed toward the object side, and a positive meniscus lens having a convex surface directed toward the object side. The second lens group G2 includes a biconvex positive lens and a negative meniscus lens having a concave surface directed toward the object side. The third lens group G3 includes a biconvex positive lens, an aperture stop, a biconcave negative lens, a biconvex positive lens, and a positive meniscus lens having a convex surface directed toward the object side. The fourth lens group G4 is composed of a cemented lens made up of a biconvex positive lens and a biconcave negative lens. The fifth lens group G5 is composed of a biconvex positive lens.

The aspherical surface includes both surfaces of a negative meniscus lens having a convex surface facing the object side of the first lens group, both surfaces of a biconvex positive lens existing closest to the object side of the second lens group, and the object surface side of the third lens group. From the perspective, the biconvex positive lens and the biconcave negative lens are used next to the biconvex positive lens on both sides.
Note that the fourth lens group G4 and the fifth lens group G5 move independently of the focus lens, and the wobbling lens is the fourth lens group G4.

  Below, the numerical data of each said Example are shown. Symbols are the above, f is the focal length of the entire system, fb is the back focus, f1, f2... Are the focal lengths of each lens group, IH (FIY) is the image height, Fno. Is the F number, ω is the half angle of view, Wide angle is the wide angle end, middle is the intermediate focal length state, telephoto is the telephoto end, r is the radius of curvature of each lens surface, d is the distance between the lens surfaces, nd is the refractive index of the d-line of each lens, and νd is each lens Abbe number. The total length described later is obtained by adding back focus to the distance from the lens front surface to the lens final surface. fb (back focus) represents the distance from the last lens surface to the paraxial image plane in terms of air.

The aspherical shape is represented by the following formula, where x is an optical axis with the light traveling direction being positive, and y is a direction orthogonal to the optical axis.

x = (y ² / r) / [1+ {1- (K + 1) (y / r) ² } ^1/2 ]
+ A ₄ y ⁴ + A ₆ y ⁶ + A ₈ y ⁸ + A ₁₀ y ¹⁰ + A ₁₂ y ¹²
Where r is the paraxial radius of curvature, K is the conic coefficient, and A ₄ , A ₆ , A ₈ , A ₁₀ , and A ₁₂ are the fourth, sixth, eighth, tenth, and twelfth aspheric coefficients, respectively. . In the aspheric coefficient, “e−n” (n is an integer) indicates “10 ⁻ⁿ ”.

Numerical example 1
Unit mm

Surface data Surface number rd nd νd
Object ∞ ∞
1 60.5835 3.000 1.80610 40.92
2 17.0000 13.062
3 -52.1483 2.200 1.48749 70.23
4 36.0857 1.274
5 37.6315 3.904 1.92286 18.90
6 120.5021 Variable
7 60.5278 6.628 1.73800 32.26
8 -29.7557 1.567 2.00069 25.46
9 -2077.5140 Variable
10 25.2818 5.526 1.58313 59.38
11 186.2490 2.108
12 Aperture 2.362
13 25.5283 5.477 1.49700 81.54
14 1047.3915 0.150
15 44.5072 5.250 1.49700 81.54
16 -37.8231 0.100
17 -36.2454 1.400 1.73800 32.26
18 15.8354 3.660
19 23.6072 3.805 1.80610 40.92
20 -212.0230 Variable
21 59.7094 1.824 1.92286 18.90
22 -230.3045 1.200 1.90366 31.32
23 22.2311 Variable
24 40.0940 4.470 1.49700 81.54
25 -60.7372 Variable
26 ∞ 4.000 1.51633 64.14
27 ∞ 0.800

Aspheric data first surface
k = -0.5014
Second side
k = -1.0036
A4 = 1.0637e-05, A6 = 1.0242e-08
10th page
k = 0.000
A4 = -5.5983e-06, A6 = -9.5203e-10, A8 = -2.6951e-13
19th page
k = 0.000
A4 = -5.8200e-07, A6 = 5.2931e-08, A8 = -2.3156e-10
20th page
k = 0.000
A4 = 1.1245e-05, A6 = 5.6368e-08, A8 = -3.4377e-10

Zoom data
Infinite close (0.35m)
Wide angle Medium telephoto Wide angle Medium telephoto focal length 12.249 21.897 39.081 12.099 21.376 37.934
Fno. 2.88 2.88 2.88 2.85 2.81 2.81
Angle of view 2ω 85.27 52.86 30.85 85.00 52.55 31.13
fb (in air) 16.194 17.958 16.192 15.412 18.267 18.067
Total length (in air) 140.24 122.13 131.16 140.25 122.13 131.15

d6 19.9477 10.1451 3.8548 19.9477 10.1451 3.8548
d9 30.1701 8.9967 1.5000 30.1701 8.9967 1.5000
d20 1.5000 5.8558 11.7363 2.8888 7.4894 14.7738
d23 2.1027 8.8471 27.5524 1.5007 6.8993 22.6235
d25 12.7560 14.5200 12.7543 11.9744 14.8288 14.6290

Group focal length
f1 = -24.82 f2 = 236.25 f3 = 30.26 f4 = -41.47 f5 = 49.32

Numerical example 2
Unit mm

Surface data Surface number rd nd νd
Object ∞ ∞
1 58.6864 3.000 1.80610 40.92
2 17.0000 12.928
3 -53.5699 2.200 1.48749 70.23
4 30.5832 0.911
5 33.7368 3.537 1.92286 18.90
6 74.6324 Variable
7 38.2052 3.585 1.74950 35.28
8 -205.1167 2.914
9 -68.7869 2.125 1.83481 42.71
10 -35.0421 1.400 2.00069 25.46
11 -293.5777 Variable
12 32.3812 4.371 1.58313 59.38
13 -892.4044 1.400
14 Aperture 3.166
15 33.8195 4.800 1.49700 81.54
16 -124.5967 0.243
17 654.4080 4.261 1.49700 81.54
18 -29.2764 0.150
19 -28.1624 1.400 1.73800 32.26
20 27.3034 2.628
21 45.5795 4.138 1.80610 40.92
22 -42.0061 Variable
23 68.9760 1.200 1.84666 23.78
24 15.8735 0.150
25 15.8965 2.304 1.92286 18.90
26 36.3624 1.200 1.90366 31.32
27 20.5290 Variable
28 48.0701 4.484 1.49700 81.54
29 -48.2908 Variable
30 ∞ 4.000 1.51633 64.14
31 ∞ 0.800
Image plane (imaging plane) ∞

Aspheric data first surface
k = -0.3761
Second side
k = -0.7340
A4 = 4.9746e-06, A6 = 6.0663e-09
12th page
k = 0.000
A4 = -7.1874e-06, A6 = -3.9355e-09, A8 = 1.6496e-11
21st page
k = 0.000
A4 = -1.2967e-05, A6 = 1.1846e-08, A8 = 5.0416e-11
22nd page
k = 0.000
A4 = -2.8376e-06, A6 = 1.0849e-09, A8 = 3.7505e-11

Zoom data
Infinite close (0.35m)
Wide angle Medium telephoto Wide angle Medium telephoto focal length 12.247 21.900 39.094 12.091 21.402 38.667
Fno. 2.88 2.88 2.88 2.84 2.82 2.86
Angle of view 2ω 85.28 52.66 30.86 85.09 52.34 30.64
fb (in air) 16.198 18.483 17.260 15.611 18.393 17.750
Total length (in air) 140.24 120.10 130.36 140.25 120.09 130.34

d6 24.7170 8.1251 1.5000 24.7170 8.1251 1.5000
d11 25.6827 8.4326 1.5000 25.6827 8.4326 1.5000
d21 1.5000 6.6593 12.5996 2.6399 8.3695 15.8123
d27 2.2897 8.5423 27.6386 1.7387 6.9160 23.9180
d29 12.7595 15.0448 13.8225 12.1731 14.9552 14.3125

Group focal length
f1 = -21.55 f2 = 90.00 f3 = 30.23 f4 = -38.81 f5 = 49.23

Numerical Example 3
Unit mm

Surface data Surface number rd nd νd
Object ∞ ∞
1 67.7643 3.000 1.80610 40.92
2 17.0000 11.658
3 -142.3447 2.200 1.48749 70.23
4 27.5273 0.469
5 29.6830 4.158 1.92286 18.90
6 66.1737 Variable
7 29.7146 3.509 1.90366 31.32
8 ∞ 2.318
9 -48.6663 2.180 1.69895 30.13
10 -32.9305 0.983
11 -34.2197 1.400 1.92286 18.90
12 260.9474 Variable
13 Aperture 1.000
14 -2252.2025 2.770 1.58313 59.38
15 -40.1104 1.255
16 -99.7019 4.638 2.00069 25.46
17 -19.6495 1.400 1.73800 32.26
18 54.3929 0.150
19 22.1463 7.939 1.49700 81.54
20 -33.6050 0.679
21 -32.8795 1.400 1.73800 32.26
22 31.8903 0.150
23 23.3029 6.102 1.49700 81.54
24 -37.3171 0.150
25 74.4593 1.912 1.80610 40.92
26 -476.0275 Variable
27 77.9333 1.000 1.80100 34.97
28 13.9062 2.792 1.92286 18.90
29 20.1990 Variable
30 44.1302 3.306 1.49700 81.54
31 -168.3136 Variable
32 ∞ 4.000 1.51633 64.14
33 ∞ 0.800
Image plane (imaging plane) ∞

Aspheric data first surface
k = -0.8522
A4 = -3.1726e-06, A6 = 2.0546e-09
Second side
k = -0.5472
A4 = -6.7600e-06, A6 = -1.3873e-08
14th page
k = 0.000
A4 = -6.3467e-06, A6 = 6.3592e-08, A8 = -3.2912e-11
15th page
k = 0.000
A4 = 1.6865e-05, A6 = 6.4131e-08
25th page
k = 0.000
A4 = -1.2756e-05, A6 = -3.9311e-08, A8 = -1.5242e-10

Zoom data
Infinite close (0.35m)
Wide-angle medium telephoto Wide-angle medium telephoto focal length 12.254 21.906 39.081 12.036 21.441 38.807
Fno. 2.88 2.88 2.88 2.83 2.82 2.73
Angle of view 2ω 85.03 53.10 31.07 85.30 52.93 31.45
fb (in air) 17.815 21.455 27.288 15.729 21.378 32.808
Total length (in air) 142.12 130.67 133.80 142.12 130.66 133.78

d6 37.7235 15.2913 1.5239 37.7235 15.2913 1.5239
d12 13.7027 7.5842 1.5000 13.7027 7.5842 1.5000
d26 1.5000 1.5000 5.9784 3.1924 2.6702 7.0227
d29 1.5004 14.9595 27.6290 1.8946 13.8573 21.0437
d31 14.3772 18.0170 23.8499 12.2907 17.9401 29.3703

Group focal length
f1 = -24.88 f2 = 90.20 f3 = 27.18 f4 = -39.72 f5 = 70.71

Numerical Example 4
Unit mm

Surface data Surface number rd nd νd
Object ∞ ∞
1 58.4109 2.800 1.80610 40.92
2 17.0000 10.206
3 -160.4354 2.200 1.48749 70.23
4 21.1892 1.254
5 24.6183 3.632 1.92286 18.90
6 43.0512 Variable
7 61.1906 2.942 1.91082 35.25
8 -45.4911 0.129
9 123.1405 2.050 1.80610 40.92
10 -147.7205 1.308
11 -24.3545 1.400 1.84666 23.78
12 98.8743 Variable
13 Aperture 1.000
14 22.1107 3.431 1.73800 32.26
15 -181.1094 8.191
16 -27.1087 1.400 1.73800 32.26
17 20.6824 0.150
18 14.7546 5.258 1.49700 81.54
19 -28.3256 0.230
20 -79.3784 1.400 1.73800 32.26
21 14.6593 5.249 1.49700 81.54
22 -49.1074 0.150
23 31.6813 3.771 1.84666 23.78
24 -68.2643 Variable
25 147.3516 1.000 1.80 100 34.97
26 21.9645 1.737 1.92286 18.90
27 24.3573 Variable
28 50.8870 3.100 1.49700 81.54
29 -168.7052 Variable
30 ∞ 4.000 1.51633 64.14
31 ∞ 0.800
Image plane (imaging plane) ∞

Aspheric data first surface
k = -0.84139
A4 = -4.6892e-07, A6 = 1.5690e-09
Second side
k = -1.1355
A4 = 7.0194e-06, A6 = 3.4468e-09
9th page
k = 0.000
A4 = -3.8230e-05, A6 = -1.7225e-08
10th page
k = 0.000
A4 = -6.1134e-05, A6 = -7.5117e-09
18th page
k = 0.000
A4 = -7.2692e-05, A6 = 1.3298e-07, A8 = -1.3504e-9
19th page
k = 0.000
A4 = 6.8253e-06, A6 = 2.0571e-08, A8 = -8.1083e-10

Zoom data
Infinite close (0.35m)
Wide-angle medium telephoto Wide-angle medium telephoto focal length 12.247 21.901 39.100 11.920 21.042 35.085
Fno. 2.88 3.43 4.08 2.80 3.30 3.68
Angle of view 2ω 88.03 53.51 31.11 88.87 53.90 32.27
fb (in air) 18.407 22.243 27.202 16.195 21.508 37.165
Total length (in air) 136.25 124.83 133.86 136.24 124.81 133.80

d6 34.7285 12.9368 2.7296 34.7285 12.9368 2.7296
d12 14.4019 8.2014 1.5654 14.4019 8.2014 1.5654
d24 1.5000 3.3928 7.6824 3.3206 5.3284 9.1662
d27 1.8579 12.7049 29.3307 2.2457 11.4879 17.8281
d29 14.9694 18.8047 23.7637 12.7570 18.0705 33.7275

Group focal length
f1 = -22.09 f2 = 118.52 f3 = 27.85 f4 = -37.83 f5 = 79.03

Numerical Example 5
Unit mm

Surface data Surface number rd nd νd
Object ∞ ∞
1 59.2511 2.800 1.80610 40.92
2 17.0000 10.160
3 -166.9221 2.200 1.49700 81.54
4 19.7605 1.121
5 22.2066 4.071 1.92286 18.90
6 36.5231 Variable
7 29.3176 3.525 1.80610 40.92
8 -43.7345 0.936
9 -25.0486 1.400 1.84666 23.78
10 188.0285 Variable
11 27.2231 3.140 1.69895 30.13
12 -104.7519 2.423
13 Aperture 7.156
14 -10.8543 1.400 1.85026 32.27
15 31.1030 0.570
16 20.3235 5.175 1.49700 81.54
17 -21.5394 0.542
18 106.3960 5.434 1.48749 70.23
19 -13.7926 1.400 1.84666 23.78
20 -23.1247 0.150
21 92.0391 2.323 1.92286 18.90
22 -121.7447 Variable
23 152.8084 2.180 1.92286 18.90
24 -66.7215 1.200 1.80100 34.97
25 22.6220 Variable
26 62.3376 2.757 1.49700 81.54
27 -131.9179 Variable
28 ∞ 4.000 1.51633 64.14
29 ∞ 0.800
Image plane (imaging plane) ∞

Aspheric data first surface
k = 2.1507
A4 = -3.8746e-06, A6 = 4.6466e-10
Second side
k = -1.207
A4 = 1.3779e-05, A6 = 2.7514e-09
7th page
k = 0.000
A4 = -6.9856e-06, A6 = -7.5428e-09
8th page
k = 0.000
A4 = -2.0993e-05, A6 = -1.2872e-08
16th page
k = 0.000
A4 = -8.9591e-05, A6 = 2.8322e-07, A8 = -5.0305e-10
17th page
k = 0.000
A4 = 1.1202e-05, A6 = -8.6926e-08, A8 = -1.0239e-10

Zoom data
Infinite close (0.35m)
Wide angle Medium telephoto Wide angle Medium telephoto focal length 12.248 21.889 39.095 11.921 20.931 35.073
Fno. 2.88 3.43 4.08 2.80 3.28 3.67
Angle of view 2ω 88.07 53.52 30.99 88.68 53.69 31.51
fb (in air) 17.703 24.791 27.187 16.191 25.425 34.671
Total length (in air) 131.37 121.47 129.15 131.36 121.45 129.10

d6 35.5746 13.9821 2.2917 35.5746 13.9821 2.2917
d10 10.9997 6.2346 1.5000 10.9997 6.2346 1.5000
d22 1.5000 2.7240 8.4683 2.9266 4.1577 10.5251
d25 2.1666 10.3095 26.2793 2.2430 8.2264 16.6857
d27 14.2649 21.3526 23.7488 12.7528 21.9875 31.2330

Group focal length
f1 = -20.78 f2 = 96.62 f3 = 28.20 f4 = -36.86 f5 = 85.58

Numerical Example 6
Unit mm

Surface data Surface number rd nd νd
Object ∞ ∞
1 56.6711 2.500 1.80610 40.92
2 17.3278 9.343
3 -277.8772 1.900 1.49700 81.54
4 19.3191 1.299
5 22.0080 4.500 1.92286 18.90
6 34.4821 Variable
7 30.2005 3.683 1.80610 40.92
8 -45.9959 1.261
9 -24.6774 1.200 1.84666 23.78
10 1424.9733 Variable
11 22.4770 3.257 1.63980 34.46
12 -88.8786 2.015
13 Aperture 6.946
14 -14.9389 1.200 1.84666 23.78
15 44.6455 0.578
16 23.2441 5.452 1.49700 81.54
17 -13.4497 1.094
18 58.3671 2.215 1.92286 18.90
19 -185.5916 Variable
20 267.3182 1.917 1.92286 18.90
21 -95.8833 1.200 1.80100 34.97
22 25.9515 Variable
23 121.9942 3.072 1.49700 81.54
24 -45.9952 variable
25 ∞ 4.000 1.51633 64.14
26 ∞ 0.800
Image plane (imaging plane) ∞

Aspheric data first surface
k = 2.1038
A4 = -9.0119e-06, A6 = 1.6932e-09
Second side
k = -1.9168
A4 = 2.2431e-05, A6 = -3.7899e-08
7th page
k = 0.000
A4 = -2.2829e-06, A6 = -9.7571e-09
8th page
k = 0.000
A4 = -1.4527e-05, A6 = -2.8093e-08
16th page
k = 0.000
A4 = -1.0252e-04, A6 = 4.0780e-07, A8 = -1.1777e-09
17th page
k = 0.000
A4 = 1.3721e-05, A6 = 1.7499e-08, A8 = 1.2935e-10

Zoom data
Infinite close (0.35m)
Wide angle Medium telephoto Wide angle Medium telephoto focal length 12.248 21.902 39.090 11.964 21.030 36.607
Fno. 4.08 4.08 4.08 3.98 3.92 3.83
Angle of view 2ω 88.49 53.14 30.86 88.67 52.84 30.25
fb (in air) 16.203 24.240 27.195 16.203 24.240 27.195
Total length (in air) 123.24 109.26 117.35 123.24 109.26 117.35

d6 32.1018 10.4781 1.5000 32.1018 10.4781 1.5000
d10 14.5313 7.8072 1.5000 14.5313 7.8072 1.5000
d19 1.5000 3.2833 8.7629 2.5000 5.2113 13.2608
d22 2.9134 7.4567 22.4013 1.9134 5.5287 17.9034
d24 12.7650 20.8022 23.7571 12.7650 20.8022 23.7571

Group focal length
f1 = -20.78 f2 = 67.83 f3 = 24.14 f4 = -26.67 f5 = 54.58

Numerical Example 7
Unit mm

Surface data Surface number rd nd νd
Object ∞ ∞
1 57.1845 2.500 1.80610 40.92
2 17.0000 7.512
3 98.7145 1.900 1.49700 81.54
4 18.9752 1.625
5 22.0319 3.430 1.92286 18.90
6 28.6857 Variable
7 29.1976 3.455 1.80610 40.92
8 -68.8613 2.224
9 -24.1742 1.200 1.84666 23.78
10 -99.4181 Variable
11 18.1851 2.956 1.72047 34.71
12 203.8700 1.379
13 Aperture 4.981
14 -19.8048 1.200 1.84666 23.78
15 28.4287 0.782
16 21.3219 7.715 1.49700 81.54
17 -16.4664 0.150
18 86.9990 2.276 1.92286 18.90
19 -62.4918 Variable
20 -42.4512 1.200 1.90366 31.32
21 81.2085 Variable
22 59.0047 3.149 1.49700 81.54
23 -68.2113 Variable
24 ∞ 4.000 1.51633 64.14
25 ∞ 0.800
Image plane (imaging plane) ∞

Aspheric data first surface
k = -13.5888
A4 = -2.2579e-06, A6 = -7.7764e-10
Second side
k = -2.0180
A4 = 2.1964e-05, A6 = -4.8961e-08
7th page
k = 0.000
A4 = 6.0468e-06, A6 = -4.7379e-09
8th page
k = 0.000
A4 = -9.6098e-06, A6 = -4.5475e-08
16th page
k = 0.000
A4 = -9.4349e-05, A6 = 3.9149e-07, A8 = 8.1740e-10
17th page
k = 0.000
A4 = 1.2917e-05, A6 = 7.5270e-09, A8 = 1.4648e-09

Zoom data
Infinite close (0.35m)
Wide angle Medium telephoto Wide angle Medium telephoto focal length 12.256 21.898 38.889 12.094 21.378 36.495
Fno. 4.08 4.08 4.08 4.03 3.98 3.84
Angle of view 2ω 88.29 53.83 31.48 88.35 53.43 31.72
fb (in air) 17.036 25.497 27.963 18.235 28.164 35.665
Total length (in air) 121.08 103.53 111.33 121.08 103.53 111.33

d6 36.7060 10.9677 1.5000 36.7060 10.9677 1.5000
d10 12.3862 7.7477 1.5000 12.3862 7.7477 1.5000
d19 1.5000 4.0313 8.1710 1.5000 4.0313 8.1710
d21 2.4559 4.2874 21.1968 1.2566 1.6202 13.4948
d23 13.5982 22.0587 24.5249 14.7975 24.7259 32.2269

Group focal length
f1 = -21.38 f2 = 82.18 f3 = 27.05 f4 = -38.55 f5 = 67.62

Numerical Example 8
Unit mm

Surface data Surface number rd nd νd
Object ∞ ∞
1 238.3687 2.500 1.49700 81.54
2 17.0000 6.686
3 55.4095 1.900 1.49700 81.54
4 17.8967 4.485
5 20.3736 2.394 1.92286 18.90
6 21.2401 Variable
7 25.6638 4.500 1.80610 40.92
8 -156.8626 1.194
9 58.1263 1.200 1.90366 31.32
10 21.6003 Variable
11 19.6679 3.228 1.58313 59.38
12 178.3194 2.300
13 Aperture 5.649
14 -33.0621 5.750 1.84666 23.78
15 34.1402 0.303
16 20.1759 5.198 1.49700 81.54
17 -22.7848 1.977
18 86.1732 1.200 1.90366 31.32
19 31.2422 2.746 1.92286 18.90
20 -382.6973 variable
21 -15.2506 1.200 1.90366 31.32
22 -23.6533 Variable
23 235.8744 3.009 1.49700 81.54
24 -40.2987 Variable
25 ∞ 4.000 1.51633 64.14
26 ∞ 0.800
Image plane (imaging plane) ∞

Aspheric data first surface
k = -89.6751
A4 = -2.8283e-07, A6 = 2.8425e-11
Second side
k = -1.9991
A4 = 2.2900e-05, A6 = -4.0502e-08
7th page
k = 0.000
A4 = -9.6367e-06
11th page
k = 0.000
A4 = 9.6694e-06
16th page
k = 0.000
A4 = -3.4185e-05, A6 = 3.7690e-08, A8 = 5.4702e-11
17th page
k = 0.000
A4 = 8.4285e-06, A6 = 5.6158e-08, A8 = 3.9066e-10

Zoom data
Infinite close (0.35m)
Wide angle Medium telephoto Wide angle Medium telephoto focal length 12.247 21.896 39.061 11.879 21.058 37.063
Fno. 4.08 4.08 4.08 4.03 3.97 3.89
Angle of view 2ω 87.88 53.63 31.19 88.29 54.21 31.39
fb (in air) 16.198 24.994 27.198 16.198 24.994 27.198
Total length (in air) 127.30 116.58 128.24 127.30 116.58 128.24

d6 43.2791 15.2943 1.9104 45.1548 17.5440 5.0679
d10 4.6178 7.5710 6.7254 2.7422 5.3213 3.5679
d20 2.9282 7.9775 18.9472 2.9282 7.9775 18.9472
d22 1.5000 1.9602 14.6813 1.5000 1.9602 14.6813
d24 12.7596 21.5562 23.7603 12.7596 21.5562 23.7603

Group focal length
f1 = -21.67 f2 = 63.20 f3 = 24.86 f4 = -30.71 f5 = 64.18

Numerical Example 9
Unit mm

Surface data Surface number rd nd νd
Object ∞ ∞
1 77.1951 2.505 1.80610 40.92
2 17.0986 11.149
3 738.9914 1.915 1.49700 81.54
4 25.4262 0.157
5 24.7353 4.505 1.92286 18.90
6 44.0211 Variable
7 70.2810 2.403 1.80610 40.92
8 -72.5862 1.049
9 -24.3202 1.207 1.84666 23.78
10 -54.0452 variable
11 25.3683 3.610 1.65412 39.68
12 -67.1935 1.022
13 Aperture 7.394
14 -18.5524 1.214 1.84666 23.78
15 90.7835 0.784
16 40.3926 6.086 1.49700 81.54
17 -15.2301 0.744
18 59.0166 2.350 1.92286 18.90
19 153.5972 Variable
20 102.6552 2.153 1.92286 18.90
21 -1050.9338 1.215 1.80100 34.97
22 34.6785 Variable
23 115.2966 2.943 1.49700 81.54
24 -69.0895 Variable
25 ∞ 4.000 1.51633 64.14
26 ∞ 0.800
Image plane (imaging plane) ∞

Aspheric data first surface
k = -11.6770
A4 = 4.7923e-06, A6 = -2.1507e-09
Second side
k = -0.4722
A4 = 1.1497e-06, A6 = 1.1275e-08
7th page
k = 0.000
A4 = -1.5791e-05, A6 = -8.6919e-09
8th page
k = 0.000
A4 = -2.4951e-05, A6 = -1.4463e-08
16th page
k = 0.000
A4 = -6.2066e-05, A6 = 9.6763e-08, A8 = -6.2537e-11
17th page
k = 0.000
A4 = 1.0914e-05, A6 = -2.8994e-08, A8 = 6.9663e-11

Zoom data
Infinite close (0.35m)
Wide-angle medium telephoto Wide-angle medium telephoto focal length 12.240 21.900 39.202 12.026 21.204 36.500
Fno. 2.88 3.43 4.08 2.83 3.32 3.81
Angle of view 2ω 87.81 54.02 31.04 87.66 53.55 30.54
fb (in air) 20.043 25.445 27.209 16.249 25.797 29.509
Total length (in air) 126.74 115.82 123.32 126.75 115.80 123.29

d6 31.6255 10.8841 1.7709 31.6255 10.8841 1.7709
d10 14.2941 8.5628 1.6090 14.2941 8.5628 1.6090
d19 2.1502 1.5465 8.0051 6.9043 4.9504 16.1674
d22 2.8593 13.6173 28.9603 1.9133 9.8413 18.4621
d24 16.6051 22.0074 23.7705 12.8111 22.3590 26.0714

Group focal length
f1 = -21.58 f2 = 69.62 f3 = 32.15 f4 = -50.96 f5 = 69.50

FIG. 3, FIG. 7, FIG. 11, FIG. 15, FIG. 19, FIG. 23, FIG. 27, FIG. 31, and FIG. Aberration diagrams at the time of focusing on an object point are shown in FIGS. 4, 8, 12, 16, 20, 20, 24, 28, 32, and 36, respectively. In these aberration diagrams, (a) is the wide-angle end, (b) is the intermediate focal length state, (c) is the spherical aberration (SA), astigmatism (AS), distortion (DT), and lateral chromatic aberration at the telephoto end. (CC) is shown. In each figure, “FIY” indicates the maximum image height.

Next, the values of the conditional expressions in each example are listed.
Example 1 Example 2 Example 3 Example 4 Example 5
(1) β _4t / β _4w 1.35 1.41 1.72 1.69 1.67
(2) (d _34t -d _34w ) / f _w 0.84 0.91 0.37 0.51 0.57
(3) (d _45t −d _45w ) / f _w 2.08 2.07 2.13 2.24 1.97
(4) f ₂ / f _w 19.29 7.35 7.36 9.68 7.89
(5) f _t / f _w 3.19 3.19 3.19 3.19 3.19
(6) f _bw / f _w 1.32 1.32 1.45 1.50 1.45
(7) ν ₁₂ 70.23 70.23 70.23 70.23 81.54
(8) | ν _4p −ν _4n | 12.42 12.42 16.07 16.07 16.07
(9) | f ₄ / f _w | 3.39 3.17 3.24 3.09 3.01
(10) △ _4w / △ _5w 1.78 1.94 0.81 0.82 0.94

Example 6 Example 7 Example 8 Example 9
(1) β _4t / β _4w 1.68 1.78 1.48 1.39
(2) (d _34t -d _34w ) / f _w 0.59 0.54 1.31 0.48
(3) (d _45t -d _45w ) / f _w 1.59 1.53 1.08 2.13
_{(4) f 2 / f w} 6.71 5.16 5.69 19.86
(5) f _t / f _w 3.19 3.17 3.19 3.20
(6) f _bw / f _w 1.32 1.39 1.32 1.64
(7) ν ₁₂ 81.54 81.54 81.54 81.54
(8) ｜ ν _4p −ν _4n ｜ 16.07--16.07
(9) | f ₄ / f _w | 3.15 2.51 4.16 6.00
(10) △ _4w / △ _5w--- 1.25

  As described above, the zoom lens according to the present invention is useful when the wobbling function is also considered in the standard zoom lens so as to correspond to the moving image function.

G1 ... 1st lens group G2 ... 2nd lens group G3 ... 3rd lens group G4 ... 4th lens group G5 ... 5th lens group S ... Brightness stop C ... Cover glass I ... Image plane

Claims (12)

In order from the object side, a first lens group with negative refractive power, a second lens group with positive refractive power, a third lens group with positive refractive power, a fourth lens group with negative refractive power, and a fifth lens group with positive refractive power. Have
In zoom lenses that change the magnification by changing the interval between each group,
When zooming from the wide-angle end to the telephoto end,
The distance between the first lens group and the second lens group decreases,
The distance between the second lens group and the third lens group changes,
The distance between the third lens group and the fourth lens group increases,
The distance between the fourth lens group and the fifth lens group increases.
A zoom lens characterized by things. The zoom lens according to claim 1, wherein the following conditional expressions (1), (2), and (3) are satisfied.
1.2 <β _4t / β _4w <2.5 (1)
_{0.1 <(d 34t - d 34w} ) / f w <1.5 ··· (2)
_{0.4 <(d 45t - d 45w} ) / f w <3.2 ··· (3)
However,
β _4t is the lateral magnification of the fourth lens group at the telephoto end,
β _4w is the lateral magnification of the fourth lens group at the wide-angle end,
d _34w is an air space between the third lens group and the fourth lens group at the wide angle end;
d _34t is an air space between the third lens group and the fourth lens group at the telephoto end;
d _45w is an air space between the fourth lens group and the fifth lens group at the wide-angle end;
d _45t is an air space between the fourth lens group and the fifth lens group at the telephoto end;
_fw is the total focal length at the wide angle end. The zoom lens according to claim 2, wherein the following conditional expression (4) is satisfied.
_{2.0 <f 2 / f w <} 13.0 ··· (4)
Here, f ₂ is the focal length of the second lens group. The zoom lens according to claim 3, wherein the following conditional expressions (5) and (6) are satisfied.
3 < _ft / _fw ... (5)
1.0 <f _bw / f _w <1.9 (6)
However,
f _t is the total focal length at the telephoto end,
f _bw is the back focus at the wide-angle end
It is. The zoom lens according to claim 4, wherein the following conditional expressions (7) and (8) are satisfied.
60 <ν ₁₂ (7)
_{5 <| ν 4p - ν 4n} | <25 ··· (8)
However,
ν ₁₂ is the Abbe number of the negative second lens in the first lens group,
ν _4p is the Abbe number of the positive lens in the fourth lens group,
ν _4n is the Abbe number of the negative lens in the fourth lens group,
It is.   3. The zoom lens according to claim 2, wherein the fourth lens group moves upon focusing from an object point at infinity to a near object point. The zoom lens according to claim 6, wherein the following conditional expression (9) is satisfied.
1.0 <| f ₄ / f _w | <7.0 (9)
Here, f ₄ is the focal length of the fourth lens group. In order from the object side, a first lens group with negative refractive power, a second lens group with positive refractive power, a third lens group with positive refractive power, a fourth lens group with negative refractive power, and a fifth lens group with positive refractive power. Have
In zoom lenses that change the magnification by changing the interval between each group,
When focusing from an infinite object point to a close object point,
A zoom lens characterized in that the fourth group and the fifth group move independently. The zoom lens according to claim 8, wherein the following conditional expressions (1), (2), and (3) are satisfied.
1.2 <β _4t / β _4w <2.5 (1)
_{0.1 <(d 34t - d 34w} ) / f w <1.5 ··· (2)
_{0.4 <(d 45t - d 45w} ) / f w <3.2 ··· (3) The zoom lens according to claim 9, wherein the following conditional expression (10) is satisfied.
0.4 <△ _4w / △ _5w <2.0 (10)
However,
_Δ4w is the amount of focus movement of the fourth lens group at the wide-angle end,
_Δ5w is the amount of focus movement of the fifth lens group at the wide-angle end,
In both cases, movement in the optical axis direction is a positive sign.   3. The zoom lens according to claim 2, wherein the second lens unit moves during focusing from an object point at infinity to a closest object point.   The zoom lens according to claim 2, wherein the fifth lens unit moves during focusing from an infinite object point to a close object point.

Images