JP2018194769A - Zoom lens and optical instrument using the same - Google Patents

Abstract

To provide a zoom lens having a high magnification and a reduced entire lens length at a telephoto end so as to reduce thickness in a retracted state, and an optical instrument using the zoom lens.SOLUTION: The zoom lens has, successively from an object side to an image side, a first lens group L1 having a positive refractive power, a second lens group L2 having a negative refractive power, a third lens group L3 having a positive refractive power, a fourth lens group L4 having a negative refractive power, and a fifth lens group L5 having a positive refractive power, in which a moving amount Mi of an i-th lens group from a wide angle end to a telephoto end, a focal distance ft at the telephoto end, and lateral magnifications β2w, β2t of the second lens group at the wide angle end and the telephoto end, respectively, are each appropriately set.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a zoom lens and an optical apparatus having the same, and is particularly suitable for a zoom lens used in a digital still camera, a film camera, and a video camera and an image pickup apparatus having the same.

  In recent years, digital still cameras, video cameras, and the like using solid-state image sensors have been increasing in angle and magnification. In particular, digital still cameras are required to reduce the number of lenses and shorten the optical total length when telephoto so that the magnification at the time of retraction is reduced.

  As a zoom lens that meets these requirements, a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, and a negative lens in order from the object side to the image side. A zoom lens having a fourth lens group having a refractive power and a fifth lens group having a positive refractive power is known (Patent Documents 1 and 2).

JP2011-75985A JP 2012-48199 A

  Patent Documents 1 and 2 are proposed as examples of a 5-group zoom lens having a positive group, a negative group, a positive group, a negative group, and a positive group. These zoom lenses have achieved a high magnification of about 30 times, but the number of lenses is large and the total optical length at the telephoto end is long. It was not always enough.

  SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a zoom lens having a high magnification and a short lens length at the telephoto end to reduce the thickness when retracted, and an optical apparatus using the zoom lens.

To achieve the above object, a zoom lens according to the present invention provides:
A. A first lens group having a positive refractive power in order from the object side to the image side, a second lens group having a negative refractive index, a third lens group having a positive refractive power, and a fourth lens group having a negative refractive index A fifth lens group having a positive refractive power;
B. When the movement amount from the wide-angle end to the telephoto end of the i-th lens group is Mi, the focal length of the telephoto end is ft, and the lateral magnifications at the wide-angle end and the telephoto end of the second lens group are β2w and β2t, respectively, the following conditions Satisfy the equation. Here, Mi is defined as + for the amount of movement toward the object side and-for the amount of movement toward the image side.

0.01 <M1 / ft <0.20
7.0 <β2t / β2w <13.0
2.4 <M3 / M4 <4.5

  According to the present invention, it is possible to obtain a zoom lens in which the lens length at the time of retraction is reduced by shortening the total length of the lens at a high magnification and at the telephoto end, and an optical apparatus using the zoom lens.

Cross-sectional view of the zoom lens of Embodiment 1 at the wide-angle end Aberration diagram at the wide-angle end of the zoom lens of Example 1 Aberration diagram in the middle of the zoom lens of Example 1 Aberration diagram at the telephoto end of the zoom lens of Example 1 Lens cross-sectional view at the wide-angle end of the zoom lens according to Embodiment 2 Aberration diagram at the wide-angle end of the zoom lens of Example 2 Aberration diagram in the middle of the zoom lens of Example 2 Aberration diagram at the telephoto end of the zoom lens of Example 2 Lens cross-sectional view at the wide-angle end of the zoom lens according to Embodiment 3 Aberration diagram at the wide-angle end of the zoom lens of Example 3 Aberration diagram in the middle of zoom lens of Example 3 Aberration diagram at the telephoto end of the zoom lens of Example 3 Lens cross-sectional view at the wide-angle end of the zoom lens according to Embodiment 4 Aberration diagram at the wide-angle end of the zoom lens of Example 4 Aberration diagram in the middle of zoom lens of Example 4 Aberration diagram at the telephoto end of the zoom lens of Example 4 Cross-sectional view of the zoom lens of Example 5 at the wide-angle end Aberration diagram at the wide-angle end of the zoom lens in Example 5 Aberration diagram in the middle of zoom lens of Example 5 Aberration diagram at the telephoto end of the zoom lens of Example 5 Cross-sectional view of the zoom lens of Example 6 at the wide-angle end Aberration diagram at the wide-angle end of the zoom lens in Example 6 Aberration diagram in the middle of zoom lens of Example 6 Aberration diagram at the telephoto end of the zoom lens of Example 6 Device diagram of optical equipment (digital still camera) equipped with the zoom lens

  The zoom lens of the present invention is characterized in that the lens length at the time of retraction is reduced by shortening the total length of the lens at a high magnification and at the telephoto end. There are a negative lead type with the first lens group as the negative group and a positive lead type with the first lens group as the positive group. The positive lead type is used in this configuration to accommodate higher magnification. Yes.

  The positive lead type zoom lens mainly zooms by widening the distance between the positive group of the first lens group and the negative group of the second lens group which is a zooming group. When the magnification is increased, the distance between the first lens group and the second lens group is increased by moving the first lens group largely toward the object side, so that the total optical length is increased during telephoto. As the mechanism, the lens barrel holding the lens moves along the groove dug in the cam barrel, so the length of the groove increases as the amount of lens movement increases, and the cam barrel lengthens accordingly. Become. As a result, the thickness at the time of retraction when each lens group is folded is determined by the length of the cam barrel and tends to be thick. For this reason, the zoom lens according to the present invention is characterized in that, when telephoto, the group in front of the aperture is made compact so that the thickness when retracted is reduced. Here, the position of the diaphragm in this case is arranged between the second lens group and the third lens group.

  In order to make the group in front of the stop compact, it is sufficient to increase the refractive power of each group. However, when the magnification is increased, aberration variation becomes large, and aberration correction becomes difficult. On the other hand, when the entrance pupil position is shortened, the first lens group and the second lens group are close to the pupil, so that the lens diameter can be reduced. In particular, the diameter of the first lens unit is often determined by a zoom position slightly closer to the telephoto position from the wide-angle end. Therefore, it is important to shorten the entrance pupil position at the zoom position that determines the diameter of the first lens group.

  Therefore, the group behind the stop is made up of a positive group, a negative group, and a positive group, thereby increasing the refractive power of each group and increasing the zooming action after the third lens group to increase the first lens. The entrance pupil position at the zoom position that determines the lens diameter of the group is shortened. In addition, since the amount of movement of the first lens group and the second lens group can be suppressed by providing the variable magnification sharing after the third lens group, the first lens group and the second lens group are brought closer to the entrance pupil position. The lens diameter is reduced.

  In addition, since the height through which off-axis rays pass is reduced, it is possible to suppress the occurrence of higher-order aberrations that occur in the first lens group and the second lens group, so that the refractive power of the group before the stop is increased. It is possible to increase the magnification while suppressing the movement amount of each lens group.

  Furthermore, the fourth lens group is an image-side convex locus, and by defining the amount of movement, the variable magnification is shared within the limited space between the third lens group and the fifth lens group, thereby reducing the size. Have achieved.

  In particular, in this case, the fourth lens unit is a compensator, and when the magnification is increased, the amount of movement on the telephoto side increases, so that the field curvature fluctuation during zooming tends to increase. Therefore, by suppressing the amount of movement, fluctuations in field curvature are suppressed, and deterioration in optical performance is suppressed.

  On the other hand, as the amount of movement decreases, the variable magnification share of the fourth lens group decreases. Therefore, it is a feature of this case that the variation in optical performance and the variable magnification share are balanced by defining the amount of movement in consideration of the variable magnification share with the third lens group.

  Further, since the distance between the fourth lens group and the fifth lens group is widened at the telephoto end, the light beam diverging in the fourth lens group enters the fifth lens group at a high position away from the optical axis. As a result, performance degradation due to higher order aberrations occurs, so the performance degradation is suppressed by defining the position of the fourth lens group.

Specifically, the zoom lens of the present invention provides a zoom lens having a high magnification and a short total lens length at the telephoto end to reduce the thickness when retracted, and an optical apparatus having the zoom lens. A first lens group having a positive refractive power in order from the object side to the image side, a second lens group having a negative refractive index, a third lens group having a positive refractive power, and a fourth lens group having a negative refractive index A fifth lens group having a positive refractive power;
B. When the amount of movement from the wide-angle end to the telephoto end of the i-th lens group is Mi, the focal length of the telephoto end is ft, and the lateral magnifications at the wide-angle end and the telephoto end of the second lens group are β2w and β2t, respectively, the following conditions Satisfy the equation. Here, Mi is defined as + for the amount of movement toward the object side and-for the amount of movement toward the image side.

0.01 <M1 / ft <0.20 (1)
7.0 <β2t / β2w <13.0 (2)
2.4 <M3 / M4 <4.5 (3)
Conditional expression (1) is a conditional expression related to the amount of movement of the first lens group, and is a conditional expression mainly related to size. If the lower limit of the conditional expression is not reached, the amount of movement of the first lens group is reduced, which is advantageous for shortening the total lens length at the telephoto end. Since this is not possible, it is difficult to increase the magnification. On the other hand, if the value exceeds the upper limit value, the amount of movement of the first lens group increases, which is advantageous for obtaining a zoom ratio. However, it is difficult to suppress fluctuations in field curvature during zooming. In addition, the total lens length at the telephoto end is increased, and the thickness when retracted is increased, which is not preferable.

  Conditional expression (2) is a conditional expression regarding the variable magnification sharing of the second lens group, and is a conditional expression regarding the optical total length and the aberration variation at the time of variable magnification. If the lower limit value of the conditional expression is not reached, the variable magnification share of the second lens group becomes small, which is disadvantageous for higher magnification. Further, it is not preferable because the movement amount of the succeeding group is increased in order to obtain a zoom ratio, and the optical total length is increased. On the other hand, exceeding the upper limit of the conditional expression is advantageous for increasing the magnification because the second lens group shares more magnification, but it is useful for correcting variations in various aberrations such as field curvature and coma during zooming. It becomes difficult.

  Conditional expression (3) is a conditional expression related to the movement amount ratio between the third lens group and the fourth lens group, and is a conditional expression related to the optical total length and aberration fluctuation during zooming. If the lower limit of the conditional expression is not reached, the amount of movement of the fourth lens group, particularly the amount of movement at the zoom position closer to the telephoto, becomes large, and it becomes difficult to suppress the field curvature fluctuation at the time of zooming. On the other hand, if the upper limit of the conditional expression is exceeded, the amount of movement of the fourth lens group is smaller than the amount of movement of the third lens group, which is advantageous for suppressing field curvature fluctuations. Becomes smaller, which is not preferable for increasing the magnification.

  In each numerical example, it is more preferable to set the numerical ranges of conditional expressions (1), (2), and (3) as follows in terms of aberration correction.

0.03 <M1 / ft <0.18 (1a)
7.2 <β2t / β2w <12.5 (2a)
2.45 <M3 / M4 <4.3 (3a)
Even more preferably, the numerical range of conditional expression (1) should be set as follows.

0.05 <M1 / ft <0.16 (1b)
7.5 <β2t / β2w <12.0 (2b)
2.5 <M3 / M4 <4.0 (3b)
The object of the present invention is achieved by the above conditional expression, but more preferably, in this configuration, when the amount of movement at the time of zooming from the wide-angle end to the telephoto end of the i-th lens group is Mi,
−1.0 <M2 / M3 <−0.4 (4)
It is to satisfy the following conditional expression.

  Conditional expression (4) is a conditional expression related to the ratio of the movement amounts of the second lens group and the third lens group, and is a conditional expression related to the optical total length and aberration fluctuations during zooming. If the lower limit value of the conditional expression is not reached, the amount of movement of the second lens group with respect to the third lens group is increased, which is advantageous for obtaining a zoom ratio, but at the wide-angle end, between the first lens group and the stop. Space is required, which is not preferable because the front lens diameter increases. In addition, it becomes difficult to suppress the field curvature fluctuation during zooming. On the other hand, if the upper limit value of the conditional expression is exceeded, the amount of movement of the third lens group with respect to the second lens group increases, which undesirably increases the overall lens length. In addition, it becomes difficult to correct fluctuations in axial chromatic aberration and coma aberration during zooming.

As above, more preferably, in this configuration, when the distance on the optical axis between the fourth lens group and the fifth lens group at the wide-angle end and the telephoto end is D45w and D45t,
2.0 <D45t / D45w <3.0 (5)
It is to satisfy the following conditional expression.

  Conditional expression (5) is a conditional expression related to the distance between the fourth lens group and the fifth lens group. Since the fifth lens group has a small movement amount at the time of zooming, the telephoto side mainly due to the movement of the fourth lens group. It is a conditional expression regarding the aberration correction. If the lower limit of the conditional expression is not reached, the amount of movement of the fourth lens group is reduced, and the variable magnification sharing is reduced, which is disadvantageous for higher magnification. Further, the amount of movement of other zooming groups is increased, which leads to an increase in the total lens length, which is not preferable. On the other hand, when the value exceeds the upper limit, the distance between the fourth and fifth lens groups is widened at the telephoto end, so that higher-order aberrations occur due to incidence of off-axis rays at a high position of the fifth lens group, and field curvature It is difficult to suppress various aberrations such as coma.

As above, more preferably, in this configuration, when the distance on the optical axis between the third lens group and the fourth lens group at the wide-angle end and the telephoto end is D34w and D34t,
1.8 <D34t / D34w <2.5 (6)
It is to satisfy the following conditional expression.

  Conditional expression (6) is a conditional expression related to the distance between the third lens group and the fourth lens group, and particularly is a conditional expression related to aberration correction at the time of zooming. If the lower limit of the conditional expression is not reached, the amount of movement of the fourth lens unit increases and the distance between the third and fourth lens units becomes narrow at the telephoto end, which is advantageous for increasing the zoom ratio. It becomes difficult to suppress aberration fluctuations such as curvature and coma. On the other hand, exceeding the upper limit is advantageous for increasing the amount of movement of the third lens unit and increasing the zoom ratio, but is not preferable because the total lens length increases. Further, the drop in Fno accompanying zooming becomes large and the brightness at the telephoto end becomes dark, which is not preferable.

As above, more preferably, in the configuration, when the thickness of the first lens group and the second lens group on the optical axis is D1 and D2, respectively,
0.01 <(D1 + D2) / ft <0.12 (7)
It is to satisfy the following conditional expression.

  Conditional expression (7) is a conditional expression related to the size of the first lens group and the second lens group, and particularly is a conditional expression related to the thickness when retracted. If the lower limit value of the conditional expression is not reached, the thickness of the first lens group and the second lens group is reduced, which is advantageous for downsizing, but the refractive power of each lens of the first and second lens groups is weakened. This makes it difficult to correct lateral chromatic aberration on the wide-angle side and axial chromatic aberration on the telephoto side. On the other hand, if the value exceeds the upper limit value, the first lens group and the second lens group are thick, which is not preferable because the thickness of the camera when retracted is thick.

As above, more preferably, in this configuration, when the lateral magnification at the telephoto end of the fourth lens group is β4t, and the combined lateral magnification at the telephoto end of the image side group from the fourth lens group is βrt,
−2.5 <(1-β4t ^ 2) × βrt ^ 2 <−1.4 (8)
It is to satisfy the following conditional expression.

  Conditional expression (8) is a conditional expression related to the lateral magnification of the fourth lens group and the lateral magnification of the image side group from the fourth lens group, and is particularly a conditional expression related to performance during focusing. If the lower limit value of the conditional expression is not reached, the amount of movement of the group becomes small at the time of focusing from infinity to the nearest point, which is advantageous in terms of aberration fluctuations, but it becomes difficult to cope with minute movements in terms of control. On the other hand, when the value exceeds the upper limit, the amount of movement of the group at the time of focusing becomes large and aberration fluctuations become large. In addition, an increase in the amount of movement is not preferable because it increases the overall length of the lens by securing a movement space.

As above, more preferably, in this configuration, when the focal length of the fifth lens group is f5, and the distance on the optical axis from the image side surface of the final lens to the imaging surface at the wide angle end is bfw,
0.18 <bfw / f5 <0.30 (9)
It is to satisfy the following conditional expression.

  Conditional expression (9) is a conditional expression related to the distance on the optical axis from the image side surface of the final lens to the imaging surface and the focal length of the fifth lens group, and particularly is related to the optical performance of the entire zoom range. If the lower limit value of the conditional expression is not reached, the refractive power of the fifth lens group becomes weak, which makes it difficult to correct lateral chromatic aberration and coma aberration in the entire zoom range. In addition, the space after the last lens is shortened, which makes it difficult to secure a mechanical space. On the other hand, if the upper limit is exceeded, the refractive power of the fifth lens group will increase, making it difficult to correct field curvature over the entire zoom range.

  In each numerical example, it is more preferable to set the numerical ranges of the conditional expressions (4) to (8) as follows in terms of aberration correction.

−0.9 <M2 / M3 <−0.45 (4a)
2.2 <D45t / D45w <2.95 (5a)
1.85 <D34t / D34w <2.4 (6a)
0.03 <(D1 + D2) / ft <0.12 (7a)
-2.45 <(1-β4t ^ 2) × βrt ^ 2 <−1.45 (8a)
0.19 <bfw / f5 <0.29 (9a)
More preferably, the numerical ranges of the conditional expressions (4) to (8) are set as follows.

−0.8 <M2 / M3 <−0.5 (4b)
2.4 <D45t / D45w <2.9 (5b)
1.9 <D34t / D34w <2.3 (6b)
0.05 <(D1 + D2) / ft <0.12 (7b)
-2.4 <(1-β4t ^ 2) × βrt ^ 2 <-1.5 (8b)
0.20 <bfw / f5 <0.28 (9b)
Further, at the time of shooting, the whole or part of the third lens unit L3 is moved in the direction perpendicular to the optical axis (the whole or part of the third lens unit is moved substantially perpendicularly to the direction of the optical axis). The image is shifted in the straight direction. This corrects blurring of the captured image when the entire optical system vibrates.

  In the zoom lens of each numerical example, correction of distortion among various aberrations may be corrected by electrical image processing. In particular, the wide-angle side contributes to the reduction of the front lens diameter by making the imaging range smaller than the effective imaging range of the sensor and correcting the distortion aberration.

  In each numerical embodiment, by configuring each lens group as described above, a zoom lens having a high magnification and a short total lens length at the telephoto end to reduce the thickness when retracted and an optical apparatus having the zoom lens can be obtained.

  Embodiments (numerical examples) of a zoom lens according to the present invention will be described below with reference to the drawings.

In the following description and drawings, ri is the radius of curvature of the i-th surface from the object side, di is the surface interval between the i-th surface and the i + 1-th surface from the object side, and ni is d of the i-th lens. The refractive index in the line, ni, indicates the Abbe number in the d line of the i-th lens. Further, k is a conic constant, A4, A6, and A8 are fourth-order, sixth-order, and eighth-order aspheric coefficients, and the displacement in the optical axis direction at the height h from the optical axis is based on the surface vertex. When X is an aspherical shape,
X = (h ² / R) / [1+ [1− (1 + K) (h / R) ² ] ^1/2 ] + A4h ⁴ + A6h ⁶ + A8h ⁸
Is displayed.

However, R is a radius of curvature, and “e−X” means “× 10 ^−X ”. For aspheric surfaces, an asterisk (*) is attached to the right side of the surface number in each table.

  Next, the lens configuration of each lens group will be described. In Numerical Examples 1 to 6, in order from the object side to the image side, a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, a third lens group having a positive refractive power, and a first lens unit having a negative refractive power. It is composed of four lens groups and a fifth lens group having a positive refractive power.

  The first lens unit L1 includes a cemented lens obtained by cementing a negative lens and a positive lens, and a single meniscus positive lens having a convex object side surface. In the zoom lens of each numerical example, the refractive power of the first lens unit L1 is increased within an appropriate range in order to reduce the size. When the refracting power is increased, various aberrations that occur in the first lens unit L1, especially spherical aberrations, occur on the telephoto side. Therefore, the positive refractive power of the first lens unit L1 is shared by the cemented lens and one positive lens to reduce the occurrence of these aberrations.

  In the second lens unit L2, the absolute value of the refractive power is stronger on the image side than on the object side, and the image side lens surface has a concave negative lens, a biconcave negative lens, and the object side lens surface has a convex shape. It is composed of three positive lenses. In the zoom lens of each numerical example, the refractive power of the second lens unit L2 is increased within an appropriate range in order to reduce the effective diameter of the first lens unit L1 while obtaining a wide angle of view at the wide angle end. When the refracting power is increased, various aberrations that occur in the second lens unit L2, in particular, curvature of field and lateral chromatic aberration occur frequently on the wide angle side. In each embodiment, the negative refractive power of the second lens unit L2 is shared by two negative lenses to reduce the occurrence of field curvature. Further, the chromatic aberration of magnification is suppressed by using high-dispersion glass for the positive lens. With such a lens configuration, the effective diameter of the front lens is reduced and high optical performance is obtained while widening the angle.

  The third lens unit L3 includes a positive lens having a convex lens surface on the object side, a negative lens having a concave lens surface on the image side, and a positive lens having a convex lens surface on the object side. In the zoom lens according to each numerical example, the refractive power of the third lens unit L3 is increased within an appropriate range in order to shorten the entire lens length at the wide-angle end and shorten the moving amount at the time of zooming. When the refracting power is increased, various aberrations that occur in the third lens unit L3, particularly axial chromatic aberration and coma aberration, often occur. Therefore, the third lens unit L3 shares the refractive power with two positive lenses and a negative lens to reduce achromaticity and coma.

  The fourth lens unit L4 includes one negative lens having a concave lens surface on the image side. In the zoom lens according to each numerical example, the fourth lens unit is configured with a small number of lenses to achieve a reduction in thickness and weight. In particular, the concave shape on the image side suppresses coma aberration in the entire zoom range, and suppresses fluctuations in field curvature that occur during focusing from infinity to the close side, particularly on the telephoto side.

  The fifth lens unit L5 includes one positive lens having a convex object-side lens surface. In the zoom lens according to each numerical example, the fifth lens unit is configured with a small number of lenses to reduce the thickness and weight. In particular, coma aberration in the middle of the zoom and lateral chromatic aberration in the entire zoom range are reduced.

  The zoom lens of each numerical example is a photographic lens system used in an imaging apparatus, and in the lens cross-sectional view, the left side is the subject side and the right side is the image side. In the lens sectional views of Numerical Examples 1 to 6, L1 is a first lens group having a positive refractive power, L2 is a second lens group having a negative refractive power, and L3 is a third lens group having a positive refractive power. , L4 is a fourth lens group having a negative refractive power, and L5 is a fifth lens group having a positive refractive power. SP is an aperture stop, which is located between the second lens unit L2 and the third lens unit L3.

  GB is an optical block corresponding to an optical filter, a face plate, or the like. IP is an image plane. When used as a photographing optical system for a digital still camera or a video camera, the imaging plane of a solid-state imaging device such as a CCD sensor or a CMOS sensor corresponds to a film plane when a camera for a silver salt film is used. To do.

  In the aberration diagrams, d and g are d-line and g-line, respectively, ΔM and ΔS are meridional image plane, sagittal image plane, and lateral chromatic aberration are represented by g-line. Fno is an F number. ω is a half angle of view in the actual trace.

  In the following numerical examples, the wide-angle end and the telephoto end refer to zoom positions when the variable power lens unit is positioned at both ends of a range in which the zoom lens group can move on the optical axis.

  In Numerical Examples 1 to 6, when zooming from the wide angle end to the telephoto end, as indicated by an arrow, the first lens unit L1 is moved along a locus convex toward the image side, the second lens unit L2 is moved toward the image side, The lens unit L3 is moved to the object side. Further, the image plane variation due to zooming is corrected by moving the fourth lens unit L4 along an image-side convex locus.

  Further, an inner focus type in which focusing is performed by moving the fourth lens unit L4 on the optical axis is adopted. A solid curve 4a and a dotted curve 4b relating to the fourth lens unit L4 are movement trajectories for correcting image plane fluctuations accompanying zooming when focusing on an object at infinity and an object at close distance, respectively. Thus, by making the fourth lens unit L4 a convex locus toward the image side, the space between the fourth lens unit L4 and the fifth lens unit L5 can be effectively used, and the overall length of the lens can be effectively shortened. doing.

  Further, when focusing from an infinitely distant object to a close object at the telephoto end, the fourth lens unit L4 is moved backward as indicated by an arrow 4c. The first lens unit L1 is fixed in the optical axis direction for focusing, but may be moved as necessary for aberration correction.

  The fifth lens unit L5 may be fixed or moved during zooming. When the fifth lens group is fixed at the time of zooming, a motor or the like for moving the group is not necessary, so that a simple configuration can be taken. On the other hand, if the fifth lens unit is moved during zooming, it can be shared by zooming by moving to the image side, which is advantageous for miniaturization and aberration correction.

  Next, an embodiment of an optical apparatus (digital still camera) using the zoom lens of the present invention as a photographing optical system will be described with reference to FIG.

  In FIG. 25, 20 is a digital still camera body, and 21 is a photographing optical system constituted by any one of the zoom lenses described in the first to sixth embodiments.

  Reference numeral 22 denotes a solid-state imaging device (photoelectric conversion device) such as a CCD sensor or a CMOS sensor that receives a subject image formed by the photographing optical system 21 and is built in the camera body. A memory 23 records information corresponding to a subject image photoelectrically converted by the solid-state imaging device 22. Reference numeral 24 denotes a finder configured by a liquid crystal display panel or the like for observing a subject image photoelectrically converted by the photographed image 22.

  Tables 1 to 6 below show the numerical values of the zoom lenses of Numerical Examples 1 to 6, respectively.

Table 1 Numerical Example 1
Surface data surface number rd nd vd
1 39.412 0.90 1.85478 24.8
2 24.582 2.99 1.59282 68.6
3 -1411.077 0.17
4 27.389 1.87 1.59282 68.6
5 97.833 (variable)
6 * 814.542 0.55 1.85 135 40.1
7 * 7.754 2.99
8 -8.510 0.42 1.71300 53.9
9 13.961 0.20
10 * 9.170 1.55 2.00178 19.3
11 37.081 (variable)
12 (Aperture) ∞ 0.00
13 * 5.204 2.39 1.55332 71.7
14 * -18.355 0.86
15 13.374 0.40 1.95375 32.3
16 4.548 0.23
17 5.991 1.58 1.62299 58.2
18 47.735 (variable)
19 * 64.454 0.60 1.69350 53.2
20 * 9.678 (variable)
21 * 13.014 2.67 1.69350 53.2
22 * -43.860 (variable)
23 ∞ 0.80 1.51633 64.1
24 ∞ (variable)
Image plane ∞

Aspheric data 6th surface
K = 0.00000e + 000 A 4 = 8.21416e-005 A 6 = 2.74687e-006 A 8 = -2.95536e-008

7th page
K = 0.00000e + 000 A 4 = -2.41428e-004 A 6 = 7.32854e-006 A 8 = 1.20513e-007

10th page
K = 0.00000e + 000 A 4 = -5.21261e-004 A 6 = 7.28742e-006 A 8 = -1.35973e-007

Side 13
K = 0.00000e + 000 A 4 = -5.29263e-004 A 6 = -9.58166e-006

14th page
K = 0.00000e + 000 A 4 = 5.57194e-004 A 6 = 5.02167e-006

19th page
K = 0.00000e + 000 A 4 = 3.53889e-003 A 6 = -4.56908e-004 A 8 = 1.96578e-005

20th page
K = 0.00000e + 000 A 4 = 4.11756e-003 A 6 = -4.80940e-004 A 8 = 1.99425e-005

21st page
K = 0.00000e + 000 A 4 = 1.20006e-004 A 6 = -7.42046e-009

22nd page
K = 0.00000e + 000 A 4 = -1.56432e-004 A 6 = 1.61569e-006

Various data Zoom ratio 21.87
Wide angle Medium Telephoto focal length 4.94 38.07 108.06
F number 3.61 5.74 6.68
Angle of view 34.14 5.81 2.05
Total lens length 51.01 63.34 67.83
BF 2.95 2.95 2.95

d 5 0.41 18.69 24.31
d11 18.76 4.86 0.50
d18 3.87 13.15 7.93
d20 4.64 3.32 11.77
d22 1.50 1.50 1.50
d24 0.92 0.92 0.92

Zoom lens group data group Start surface Focal length Lens construction length
1 1 37.25 5.93
2 6 -5.72 5.72
3 12 9.79 5.45
4 19 -16.49 0.60
5 21 14.76 2.67


Table 2 Numerical Example 2
Surface data surface number rd nd vd
1 39.525 0.90 1.85478 24.8
2 24.667 2.98 1.59282 68.6
3 -1742.912 0.17
4 27.291 1.86 1.59282 68.6
5 95.249 (variable)
6 * -1554.944 0.55 1.85 135 40.1
7 * 7.910 3.03
8 -8.151 0.42 1.71300 53.9
9 14.345 0.20
10 * 9.368 1.55 2.00178 19.3
11 41.756 (variable)
12 (Aperture) ∞ 0.00
13 * 5.264 2.39 1.55332 71.7
14 * -17.318 0.89
15 14.517 0.40 1.95375 32.3
16 4.673 0.23
17 6.211 1.54 1.62299 58.2
18 66.408 (variable)
19 * -592.354 0.60 1.69350 53.2
20 * 11.677 (variable)
21 * 13.228 2.67 1.69350 53.2
22 * -40.434 (variable)
23 ∞ 0.80 1.51633 64.1
24 ∞ (variable)
Image plane ∞

Aspheric data 6th surface
K = 0.00000e + 000 A 4 = 9.02149e-005 A 6 = 3.76334e-006 A 8 = -3.77017e-008

7th page
K = 0.00000e + 000 A 4 = -2.69975e-004 A 6 = 8.18001e-006 A 8 = 1.59537e-007

10th page
K = 0.00000e + 000 A 4 = -5.37911e-004 A 6 = 8.13842e-006 A 8 = -1.59519e-007

Side 13
K = 0.00000e + 000 A 4 = -5.42231e-004 A 6 = -8.14724e-006

14th page
K = 0.00000e + 000 A 4 = 5.46087e-004 A 6 = 5.83975e-006

19th page
K = 0.00000e + 000 A 4 = 4.80248e-003 A 6 = -6.47224e-004 A 8 = 3.07837e-005

20th page
K = 0.00000e + 000 A 4 = 5.50742e-003 A 6 = -6.77465e-004 A 8 = 3.09628e-005

21st page
K = 0.00000e + 000 A 4 = 1.33759e-004 A 6 = -6.72656e-007

22nd page
K = 0.00000e + 000 A 4 = -1.97129e-004 A 6 = 3.01678e-006

Various data Zoom ratio 21.87
Wide angle Medium Telephoto focal length 4.94 39.64 108.06
F number 3.61 5.76 6.51
Angle of view 34.14 5.58 2.05
Total lens length 51.12 64.06 67.83
BF 2.95 2.95 2.95

d 5 0.41 19.20 24.66
d11 18.69 4.74 0.50
d18 3.99 13.41 8.10
d20 4.69 3.38 11.24
d22 1.50 1.50 1.50
d24 0.92 0.92 0.92

Zoom lens group data group Start surface Focal length Lens construction length
1 1 37.50 5.91
2 6 -5.68 5.76
3 12 9.81 5.44
4 19 -16.51 0.60
5 21 14.67 2.67


Table 3 Numerical Example 3
Surface data surface number rd nd vd
1 37.326 0.90 1.85478 24.8
2 23.792 3.06 1.59282 68.6
3 -2702.515 0.17
4 27.578 1.81 1.59282 68.6
5 89.672 (variable)
6 * -508.004 0.55 1.85 135 40.1
7 * 8.084 3.01
8 -7.873 0.42 1.71300 53.9
9 14.518 0.24
10 * 9.964 1.62 2.00178 19.3
11 54.692 (variable)
12 (Aperture) ∞ 0.00
13 * 5.229 2.40 1.55332 71.7
14 * -17.033 0.86
15 14.012 0.40 1.95375 32.3
16 4.619 0.23
17 6.116 1.57 1.62299 58.2
18 57.009 (variable)
19 * -74.498 0.60 1.69350 53.2
20 * 12.741 (variable)
21 * 13.287 2.72 1.69350 53.2
22 * -31.707 (variable)
23 ∞ 0.80 1.51633 64.1
24 ∞ (variable)
Image plane ∞

Aspheric data 6th surface
K = 0.00000e + 000 A 4 = 2.01459e-004 A 6 = -3.95693e-006 A 8 = 8.42533e-008

7th page
K = 0.00000e + 000 A 4 = -1.40104e-004 A 6 = 3.44975e-006 A 8 = -8.91210e-008

10th page
K = 0.00000e + 000 A 4 = -4.84653e-004 A 6 = 9.00827e-006 A 8 = -2.49278e-007

Side 13
K = 0.00000e + 000 A 4 = -5.76140e-004 A 6 = -6.66307e-006

14th page
K = 0.00000e + 000 A 4 = 5.42149e-004 A 6 = 8.44074e-006

19th page
K = 0.00000e + 000 A 4 = 4.97364e-003 A 6 = -6.22727e-004 A 8 = 2.95661e-005

20th page
K = 0.00000e + 000 A 4 = 5.61977e-003 A 6 = -6.37874e-004 A 8 = 2.89622e-005

21st page
K = 0.00000e + 000 A 4 = 3.04296e-004 A 6 = -1.95435e-006

22nd page
K = 0.00000e + 000 A 4 = 2.02271e-004 A 6 = -4.00202e-006

Various data Zoom ratio 21.88
Wide angle Medium Telephoto focal length 4.94 36.20 108.06
F number 3.61 5.69 6.50
Angle of view 34.15 6.11 2.05
Total lens length 51.13 63.15 67.83
BF 2.95 2.95 2.95

d 5 0.46 18.40 24.49
d11 18.49 4.95 0.50
d18 3.83 12.77 7.57
d20 4.84 3.52 11.76
d22 1.50 1.50 1.50
d24 0.92 0.92 0.92

Zoom lens group data group Start surface Focal length Lens construction length
1 1 37.29 5.94
2 6 -5.63 5.84
3 12 9.68 5.46
4 19 -15.65 0.60
5 21 13.84 2.72


Table 4 Numerical Example 4
Surface data surface number rd nd vd
1 44.756 0.90 1.85478 24.8
2 27.357 2.80 1.59282 68.6
3 -509.172 0.17
4 27.047 1.79 1.59282 68.6
5 80.889 (variable)
6 * -4392.293 0.55 1.85 135 40.1
7 * 7.458 3.16
8 -8.607 0.42 1.71300 53.9
9 14.738 0.20
10 * 9.078 1.55 2.00178 19.3
11 34.014 (variable)
12 (Aperture) ∞ 0.00
13 * 5.363 2.12 1.55332 71.7
14 * -17.336 1.15
15 14.938 0.40 1.95375 32.3
16 4.716 0.23
17 6.286 1.42 1.62299 58.2
18 76.234 (variable)
19 * 582.875 0.60 1.69350 53.2
20 * 9.884 (variable)
21 * 14.939 2.80 1.69350 53.2
22 * -20.694 (variable)
23 ∞ 0.80 1.51633 64.1
24 ∞ (variable)
Image plane ∞

Aspheric data 6th surface
K = 0.00000e + 000 A 4 = 2.65263e-004 A 6 = -2.18781e-006 A 8 = 2.71691e-009

7th page
K = 0.00000e + 000 A 4 = -2.77044e-005 A 6 = 8.29076e-006 A 8 = 9.48912e-008

10th page
K = 0.00000e + 000 A 4 = -5.21575e-004 A 6 = 7.91929e-006 A 8 = -1.57383e-007

Side 13
K = 0.00000e + 000 A 4 = -5.49116e-004 A 6 = -7.63013e-006

14th page
K = 0.00000e + 000 A 4 = 4.71200e-004 A 6 = 4.92078e-006

19th page
K = 0.00000e + 000 A 4 = 4.56354e-003 A 6 = -6.05677e-004 A 8 = 2.77808e-005

20th page
K = 0.00000e + 000 A 4 = 5.24741e-003 A 6 = -6.29829e-004 A 8 = 2.77455e-005

21st page
K = 0.00000e + 000 A 4 = 1.63253e-004 A 6 = -2.69320e-006

22nd page
K = 0.00000e + 000 A 4 = -2.64821e-005 A 6 = -2.28643e-007

Various data Zoom ratio 29.00
Wide angle Medium telephoto focal length 4.63 47.24 134.25
F number 3.61 6.04 7.10
Angle of view 35.89 4.69 1.65
Total lens length 53.18 67.79 72.32
BF 2.94 2.94 2.94

d 5 0.40 22.11 27.55
d11 20.53 4.47 0.45
d18 3.82 14.95 7.37
d20 5.24 3.05 13.76
d22 1.50 1.50 1.50
d24 0.92 0.92 0.92

Zoom lens group data group Start surface Focal length Lens construction length
1 1 39.70 5.65
2 6 -5.58 5.87
3 12 9.91 5.33
4 19 -14.50 0.60
5 21 12.93 2.80


Table 5 Numerical Example 5
Surface data surface number rd nd vd
1 40.899 0.90 1.85478 24.8
2 26.258 2.76 1.59282 68.6
3 2944.615 0.17
4 28.580 1.69 1.59282 68.6
5 81.193 (variable)
6 * -1373.805 0.55 1.85 135 40.1
7 * 6.829 3.31
8 -9.473 0.42 1.71300 53.9
9 16.258 0.20
10 * 9.382 1.54 2.00178 19.3
11 35.767 (variable)
12 (Aperture) ∞ 0.00
13 * 5.399 2.16 1.55332 71.7
14 * -16.866 1.07
15 16.464 0.40 1.95375 32.3
16 4.858 0.22
17 6.542 1.42 1.62299 58.2
18 144.694 (variable)
19 * -812.891 0.60 1.69350 53.2
20 * 9.967 (variable)
21 * 15.610 2.77 1.69350 53.2
22 * -19.608 (variable)
23 ∞ 0.80 1.51633 64.1
24 ∞ (variable)
Image plane ∞

Aspheric data 6th surface
K = 0.00000e + 000 A 4 = 3.58427e-004 A 6 = -5.50161e-006 A 8 = 2.60268e-008

7th page
K = 0.00000e + 000 A 4 = 1.05318e-004 A 6 = 1.08302e-005 A 8 = 9.34376e-008

10th page
K = 0.00000e + 000 A 4 = -4.49454e-004 A 6 = 7.25954e-006 A 8 = -1.69134e-007

Side 13
K = 0.00000e + 000 A 4 = -5.43868e-004 A 6 = -6.48694e-006

14th page
K = 0.00000e + 000 A 4 = 4.73748e-004 A 6 = 5.60832e-006

19th page
K = 0.00000e + 000 A 4 = 4.58087e-003 A 6 = -6.12507e-004 A 8 = 2.81094e-005

20th page
K = 0.00000e + 000 A 4 = 5.22444e-003 A 6 = -6.28148e-004 A 8 = 2.77243e-005

21st page
K = 0.00000e + 000 A 4 = 1.14875e-004 A 6 = -1.73664e-006

22nd page
K = 0.00000e + 000 A 4 = -2.20359e-005 A 6 = -2.13632e-008

Various data Zoom ratio 32.00
Wide angle Medium Telephoto focal length 4.38 47.52 140.27
F number 3.61 6.12 7.10
Angle of view 37.38 4.66 1.58
Total lens length 53.62 69.40 74.52
BF 2.94 2.94 2.94

d 5 0.40 23.51 29.33
d11 21.24 4.40 0.45
d18 4.13 15.38 7.63
d20 4.74 3.00 14.00
d22 1.50 1.50 1.50
d24 0.91 0.91 0.91

Zoom lens group data group Start surface Focal length Lens construction length
1 1 41.51 5.52
2 6 -5.60 6.02
3 12 10.01 5.27
4 19 -14.19 0.60
5 21 12.95 2.77


Table 6 Numerical Example 6
Surface data surface number rd nd vd
1 39.935 0.90 1.85478 24.8
2 24.744 3.00 1.59282 68.6
3 -920.531 0.17
4 28.001 1.84 1.59282 68.6
5 99.742 (variable)
6 * -510.068 0.55 1.85 135 40.1
7 * 7.871 2.93
8 -8.787 0.42 1.71300 53.9
9 14.084 0.21
10 * 9.325 1.56 2.00178 19.3
11 40.566 (variable)
12 (Aperture) ∞ 0.00
13 * 5.167 2.39 1.55332 71.7
14 * -19.165 0.78
15 12.948 0.40 1.95375 32.3
16 4.498 0.23
17 5.904 1.58 1.62299 58.2
18 42.727 (variable)
19 * 51.575 0.60 1.69350 53.2
20 * 9.231 (variable)
21 * 11.945 2.80 1.69350 53.2
22 * -70.577 (variable)
23 ∞ 0.80 1.51633 64.1
24 ∞ (variable)
Image plane ∞

Aspheric data 6th surface
K = 0.00000e + 000 A 4 = 1.41295e-004 A 6 = 1.06255e-006 A 8 = -1.38337e-008

7th page
K = 0.00000e + 000 A 4 = -1.87209e-004 A 6 = 7.88468e-006 A 8 = 8.81133e-008

10th page
K = 0.00000e + 000 A 4 = -5.07230e-004 A 6 = 7.77386e-006 A 8 = -1.58719e-007

Side 13
K = 0.00000e + 000 A 4 = -5.17883e-004 A 6 = -9.89335e-006

14th page
K = 0.00000e + 000 A 4 = 5.59741e-004 A 6 = 5.00312e-006

19th page
K = 0.00000e + 000 A 4 = 3.18046e-003 A 6 = -4.05926e-004 A 8 = 1.89198e-005

20th page
K = 0.00000e + 000 A 4 = 3.68640e-003 A 6 = -4.20876e-004 A 8 = 1.91769e-005

21st page
K = 0.00000e + 000 A 4 = -1.84148e-005 A 6 = 4.12113e-006

22nd page
K = 0.00000e + 000 A 4 = -3.46557e-004 A 6 = 5.27899e-006

Various data Zoom ratio 21.89
Wide angle Medium Telephoto focal length 4.94 37.60 108.06
F number 3.61 5.84 6.90
Angle of view 34.16 5.88 2.05
Total lens length 51.13 63.41 67.83
BF 2.95 2.41 2.31

d 5 0.44 18.83 24.56
d11 18.97 5.09 0.50
d18 3.89 12.59 8.39
d20 4.53 4.13 11.72
d22 1.50 0.96 0.86
d24 0.92 0.92 0.92

Zoom lens group data group Start surface Focal length Lens construction length
1 1 37.74 5.90
2 6 -5.86 5.67
3 12 9.83 5.38
4 19 -16.31 0.60
5 21 14.94 2.80

L1 first group, L2 second group, L3 third group, L4 fourth group, L5 fifth group,
SP aperture, GB glass block, IP image plane, dd line, gg line,
Fno F number, w half angle of view, S sagittal image plane, M meridional image plane

Claims (9)

A first lens group having a positive refractive power in order from the object side to the image side, a second lens group having a negative refractive index, a third lens group having a positive refractive power, and a fourth lens group having a negative refractive index A fifth lens group having a positive refractive power;
When the amount of movement from the wide-angle end to the telephoto end of the i-th lens group is Mi, the focal length of the telephoto end is ft, and the lateral magnifications at the wide-angle end and the telephoto end of the second lens group are β2w and β2t, respectively, the following conditions A zoom lens characterized by satisfying the formula.
Here, Mi is defined as + for the amount of movement toward the object side and-for the amount of movement toward the image side.
0.01 <M1 / ft <0.20
7.0 <β2t / β2w <13.0
2.5 <M3 / M4 <4.5 2. The zoom lens according to claim 1, wherein the following conditional expression is satisfied, where Mi is an amount of movement of the i-th lens group upon zooming from the wide-angle end to the telephoto end.
−1.0 <M2 / M3 <−0.4 The following conditional expressions are satisfied, where the distances on the optical axis between the fourth lens unit and the fifth lens unit at the wide-angle end and the telephoto end are D45w and D45t, respectively. Item 3. The zoom lens according to Item 2.
2.0 <D45t / D45w <3.0 The following conditional expressions are satisfied, where the distances on the optical axis between the third lens group and the fourth lens group at the wide-angle end and the telephoto end are D34w and D34t, respectively. The zoom lens according to any one of Items 3 to 4.
1.8 <D34t / D34w <2.5 The following conditional expressions are satisfied, where the thicknesses on the optical axis of the first lens group and the second lens group are D1 and D2, respectively. The described zoom lens.
0.01 <(D1 + D2) / ft <0.12 When the lateral magnification at the telephoto end of the fourth lens group is β4t and the combined lateral magnification at the telephoto end of the image side group from the fourth lens group is βrt, the following conditional expression is satisfied: The zoom lens according to any one of claims 1 to 5.
−2.2 <(1-β4t ^ 2) × βrt ^ 2 <−1.4   The zoom according to any one of claims 1 to 6, wherein the whole or a part of the third lens group is moved vertically in the optical axis direction to correct image plane movement of the subject image. lens.   An optical apparatus comprising: the zoom lens according to any one of claims 1 to 7; and an effective image circle diameter at a wide angle side smaller than an effective image circle diameter at a telephoto end.   8. An optical apparatus comprising: the zoom lens according to claim 1; and an image sensor that receives an image formed by the zoom lens.