JP6584082B2 - Zoom lens and imaging apparatus having the same - Google Patents

Description

  The present invention relates to a zoom lens and an image pickup apparatus having the same, for example, an image pickup apparatus using an image pickup device such as a digital still camera, a video camera, a surveillance camera, and a broadcast camera, or an image pickup apparatus such as a camera using a silver halide photographic film. It is suitable for.

  In recent years, imaging devices such as digital still cameras and video cameras using solid-state imaging devices have become highly functional, and in particular, imaging devices equipped with imaging devices larger than conventional ones are generally known. . Zoom lenses used in these imaging devices are required to have a short overall lens length and high imaging performance.

  On the other hand, with the increase in size of the image sensor, various aberrations are likely to occur during zooming and focusing. In particular, the optical performance tends to deteriorate during focusing when shooting an object at close range. In addition, since an image is formed in a wider area, the optical system constituting the zoom lens is also easily increased in size. Accordingly, it is important to appropriately set the arrangement and configuration of the focus groups in order to prevent a decrease in optical performance during focusing and an increase in the size of the zoom lens.

  As a zoom lens corresponding to a large image sensor, the zoom lens described in Patent Document 1 includes a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a rear group having a plurality of lens groups. Therefore, focusing is performed by moving a part of the rear group.

JP 2009-265657 A

  In the zoom lens described in Patent Document 1, since the magnification of the optical system arranged on the image side relative to the focus group is too high, the focus sensitivity at the telephoto end becomes too high. As a result, the focusing performance may be degraded.

  It is an object of the present invention to provide a zoom lens that is small in size and has high optical performance during focusing at each subject distance, and an image pickup apparatus having the zoom lens.

The zoom lens according to the present invention includes 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, arranged in order from the object side to the image side. A zoom lens having a fourth lens group having a refractive power, a fifth lens group having a positive refractive power, and a sixth lens group having a negative refractive power, wherein an interval between adjacent lens groups is changed during zooming. During focusing to a close distance, the sixth lens group moves, and the first lens group is composed of a negative lens, a positive lens, and a positive lens arranged in order from the object side to the image side, and is at infinity at the wide-angle end. The focus sensitivity of the sixth lens group when focused is ESW, the focus sensitivity of the sixth lens group when focused at infinity at the telephoto end, EST, and the focus sensitivity of the sixth lens group Focus on f6, infinity The amount of movement of the sixth lens group during zooming from the wide-angle end to the telephoto end when moving is M6, and the sign of the amount of movement is positive when it is located on the object side at the telephoto end compared to the wide-angle end. When the position is negative,
3.50 <EST / ESW <10.00
−5.00 <f6 / M6 <−0.90
The following conditional expression is satisfied.
Another optical system according to the present invention includes a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens having a positive refractive power, which are arranged in order from the object side to the image side. This zoom lens has a first lens group, a fourth lens group having a negative refractive power, a fifth lens group having a positive refractive power, and a sixth lens group having a negative refractive power, and the distance between adjacent lens groups changes during zooming. During focusing from infinity to close distance, the sixth lens group moves, and when zooming from the wide-angle end to the telephoto end when focusing on infinity, the sixth lens group moves toward the object side. After moving, it moves to the image side, then moves to the object side, and the focus sensitivity of the sixth lens group when focused to infinity at the wide angle end is focused to ESW, and focused to infinity at the telephoto end Focus sensitivity of the sixth lens group when EST, the focal length of the sixth lens group is f6, and the amount of movement of the sixth lens group during zooming from the wide-angle end to the telephoto end when focusing on infinity is M6, and the sign of the amount of movement Is positive when positioned on the object side at the telephoto end compared to the wide-angle end, and negative when positioned on the image side.
3.50 <EST / ESW <10.00
−5.00 <f6 / M6 <−0.90
The following conditional expression is satisfied.
Another optical system according to the present invention includes a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens having a positive refractive power, which are arranged in order from the object side to the image side. Lens group, a fourth lens group having a negative refractive power, a fifth lens group having a positive refractive power, a sixth lens group having a negative refractive power, and a seventh lens group having a positive refractive power, and adjacent lens groups for zooming In the zoom lens in which the distance of the zoom lens varies, the focus sensitivity of the sixth lens group when the sixth lens group moves and is focused at infinity at the wide angle end during focusing from infinity to the close range. The degree of focus sensitivity of the sixth lens group when focusing on infinity at the telephoto end, EST, and the focal length of the sixth lens group f6, when focusing on infinity. When zooming from the wide-angle end to the telephoto end The amount of movement of the sixth lens group and M6, when the movement amount of the code is that when positioned on the object side at the telephoto end than at the wide-angle end positive, and negative when located on the image side,
3.50 <EST / ESW <10.00
−5.00 <f6 / M6 <−0.90
The following conditional expression is satisfied.

  According to the present invention, it is possible to obtain a zoom lens that is compact and has high optical performance during focusing at each subject distance.

Lens cross-sectional view at the wide-angle end of the zoom lens of Example 1 (A), (B), (C) Aberration diagrams at the wide-angle end, the intermediate zoom position, and the telephoto end of the zoom lens of Example 1. Lens sectional view at the wide-angle end of the zoom lens according to Embodiment 2 (A), (B), (C) Aberration diagrams at the wide-angle end, intermediate zoom position, and telephoto end of the zoom lens of Example 2. Lens sectional view at the wide-angle end of the zoom lens according to Embodiment 3 (A), (B), (C) Aberration diagrams at the wide-angle end, the intermediate zoom position, and the telephoto end of the zoom lens according to the third exemplary embodiment. Lens sectional view at the wide-angle end of the zoom lens according to Embodiment 4 (A), (B), (C) Aberration diagrams at the wide-angle end, intermediate zoom position, and telephoto end of the zoom lens of Example 4. Lens sectional view at the wide-angle end of the zoom lens according to Embodiment 5 (A), (B), (C) Aberration diagrams at the wide-angle end, intermediate zoom position, and telephoto end of the zoom lens of Example 5. Lens cross-sectional view at the wide-angle end of the zoom lens according to Embodiment 6 (A), (B), (C) Aberration diagrams at the wide-angle end, intermediate zoom position, and telephoto end of the zoom lens of Example 6. Lens cross-sectional view at the wide-angle end of the zoom lens according to the seventh exemplary embodiment (A), (B), (C) Aberration diagrams at the wide-angle end, intermediate zoom position, and telephoto end of the zoom lens of Example 7. Lens cross-sectional view at the wide-angle end of the zoom lens according to Embodiment 8 (A), (B), (C) Aberration diagrams at the wide-angle end, intermediate zoom position, and telephoto end of the zoom lens of Example 8. Schematic diagram of main parts of an imaging apparatus of the present invention

  Hereinafter, a zoom lens of the present invention and an image pickup apparatus having the same will be described in detail with reference to the accompanying drawings. The zoom lens according to the present invention includes, in order from the object side to the image side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, and a negative lens having a negative refractive power. It has a fourth lens group, a fifth lens group having a positive refractive power, and a sixth lens group having a negative refractive power. Here, the lens group is a lens element that moves integrally during zooming, as long as it has at least one lens and does not necessarily have to have a plurality of lenses.

  FIG. 1 is a lens cross-sectional view at the wide-angle end of the zoom lens according to the first exemplary embodiment. 2A, 2B, and 2C are aberration diagrams at the wide-angle end, the intermediate zoom position, and the telephoto end, respectively, of the zoom lens of Example 1. FIGS. Example 1 is a zoom lens having a zoom ratio of 23.24 and an aperture ratio of about 2.88 to 5.88. FIG. 3 is a lens cross-sectional view at the wide-angle end of the zoom lens according to the second exemplary embodiment. 4A, 4B, and 4C are aberration diagrams at the wide-angle end, the intermediate zoom position, and the telephoto end, respectively, of the zoom lens according to the second embodiment. The second embodiment is a zoom lens having a zoom ratio of 23.63 and an aperture ratio of about 2.77 to 5.88.

  FIG. 5 is a lens cross-sectional view at the wide-angle end of the zoom lens according to the third exemplary embodiment. FIGS. 6A, 6B, and 6C are aberration diagrams at the wide-angle end, the intermediate zoom position, and the telephoto end, respectively, of the zoom lens according to the third exemplary embodiment. Example 3 is a zoom lens having a zoom ratio of 23.66 and an aperture ratio of about 2.86 to 5.88. FIG. 7 is a lens cross-sectional view at the wide-angle end of the zoom lens according to the fourth exemplary embodiment. 8A, 8B, and 8C are aberration diagrams at the wide-angle end, the intermediate zoom position, and the telephoto end, respectively, of the zoom lens according to the fourth exemplary embodiment. The fourth exemplary embodiment is a zoom lens having a zoom ratio of 23.53 and an aperture ratio of about 2.88 to 5.77.

  FIG. 9 is a lens cross-sectional view at the wide-angle end of the zoom lens according to the fifth exemplary embodiment. FIGS. 10A, 10B, and 10C are aberration diagrams of the zoom lens of Example 5 at the wide-angle end, the intermediate zoom position, and the telephoto end, respectively. The fifth embodiment is a zoom lens having a zoom ratio of 23.56 and an aperture ratio of about 2.86 to 5.77. FIG. 11 is a lens cross-sectional view at the wide-angle end of the zoom lens according to the sixth exemplary embodiment. 12A, 12B, and 12C are aberration diagrams at the wide-angle end, the intermediate zoom position, and the telephoto end of the zoom lens according to Embodiment 6, respectively. Example 6 is a zoom lens having a zoom ratio of 23.54 and an aperture ratio of about 2.88 to 5.77.

  FIG. 13 is a lens cross-sectional view at the wide-angle end of the zoom lens according to the seventh exemplary embodiment. FIGS. 14A, 14B, and 14C are aberration diagrams of the zoom lens of Embodiment 7 at the wide-angle end, the intermediate zoom position, and the telephoto end, respectively. The seventh embodiment is a zoom lens having a zoom ratio of 28.25 and an aperture ratio of about 2.86 to 5.77. FIG. 15 is a lens cross-sectional view at the wide-angle end of the zoom lens according to the eighth embodiment. FIGS. 16A, 16B, and 16C are aberration diagrams at the wide-angle end, the intermediate zoom position, and the telephoto end, respectively, of the zoom lens of Example 8. FIGS. The eighth embodiment is a zoom lens having a zoom ratio of 23.40 and an aperture ratio of about 2.88 to 5.81.

  FIG. 17 is a schematic diagram of a main part of a digital still camera (imaging device) including the zoom lens of the present invention. The zoom lens of each embodiment is a photographic lens system used in an imaging apparatus such as a video camera, a digital still camera, a silver salt film camera, or a television camera. In the lens cross-sectional view, the left side is the object side (front), and the right side is the image side (rear). In the lens cross-sectional view, Bi represents the i-th lens group, where i is the order of the lens group from the object side to the image side.

  The zoom lenses according to the first to seventh embodiments include a first lens unit B1 having a positive refractive power, a second lens unit B2 having a negative refractive power, a third lens unit B3 having a positive refractive power, and a fourth lens unit having a negative refractive power. The lens unit includes a lens unit B4, a fifth lens unit B5 having a positive refractive power, and a sixth lens unit B6 having a negative refractive power. Examples 1 to 7 are positive lead type 6-group zoom lenses including six lens groups.

  In Example 8, the first lens unit B1 having a positive refractive power, the second lens unit B2 having a negative refractive power, the third lens unit B3 having a positive refractive power, the fourth lens unit B4 having a negative refractive power, A fifth lens unit B5 having a negative refractive power, a sixth lens unit B6 having a negative refractive power, and a seventh lens unit B7 having a positive refractive power. The eighth embodiment is a positive lead type seven-group zoom lens including seven lens groups.

  In each embodiment, SP is an aperture stop. In the zoom lenses of Examples 1 to 3 and 8, the aperture stop SP is disposed between the second lens group B2 and the third lens group B3. Thereby, size reduction of a front lens diameter is realizable. On the other hand, in the zoom lenses of Examples 4 to 7, the aperture stop SP is disposed between the third lens group B3 and the fourth lens group B4. As a result, the distance between the second lens unit B2 and the third lens unit B3 at the telephoto end can be reduced, and the zoom lens can be further increased in magnification.

  In each embodiment, the aperture stop SP moves while drawing the same locus as the third lens group during zooming. As a result, the structure of the lens barrel that holds the zoom lens can be simplified.

  GB is an optical block corresponding to an optical filter, a face plate, a low-pass filter, an infrared cut filter, or the like. IP is the image plane. When a zoom lens is used as an imaging optical system of a video camera or a digital camera, the image plane IP corresponds to a solid-state imaging device (photoelectric conversion device) such as a CCD sensor or a CMOS sensor. When a zoom lens is used as an imaging optical system of a silver salt film camera, the image plane IP corresponds to a film plane.

  In the spherical aberration diagram, Fno is an F number, and indicates spherical aberration with respect to d-line (wavelength 587.6 nm) and g-line (wavelength 435.8 nm). In the astigmatism diagram, S is a sagittal image plane, and M is a meridional image plane. Distortion is shown for the d-line. The chromatic aberration diagram shows the chromatic aberration at the g-line. ω is an imaging half angle of view.

  In each embodiment, as indicated by an arrow in the lens cross-sectional view, the lens group moves during zooming from the wide-angle end to the telephoto end, and the interval between adjacent lens groups changes. Specifically, in each embodiment, during zooming from the wide-angle end to the telephoto end, the first lens unit B1 has a convex locus toward the image side so that it is positioned closer to the object side at the telephoto end than at the wide-angle end. Move like drawing. The second lens unit B2 moves so as to be positioned on the image side at the telephoto end compared to the wide-angle end. The third lens group B3, the fourth lens group B4, the fifth lens group B5, and the sixth lens group B6 move so as to be positioned closer to the object side at the telephoto end than at the wide angle end. In the zoom lens of Example 8, the seventh lens unit B7 does not move during zooming.

  In the zoom lenses of Examples 2 to 6, the third lens unit B3 and the fifth lens unit B5 move while drawing the same locus during zooming. Thereby, the zooming mechanism can be simplified. In the zoom lenses of Examples 1, 7, and 8, the third lens unit B3 and the fifth lens unit B5 move while drawing different trajectories during zooming. Thereby, the fluctuation | variation of the coma aberration accompanying zooming can be suppressed.

  In the zoom lens of each embodiment, the distance between the first lens group B1 and the second lens group B2 is widened at the telephoto end compared to the wide angle end, and the distance between the second lens group B2 and the third lens group B3 is narrowed. In addition, each lens group moves. Thereby, it is possible to efficiently achieve a high magnification of the zoom lens.

  In the zoom lenses of the embodiments, the sixth lens group B6 is a focus group. In each lens cross-sectional view, the solid line indicating the movement locus of the sixth lens unit B6 indicates the movement locus for correcting the image plane variation accompanying zooming from the wide-angle end to the telephoto end when focusing on an object at infinity. Represents. In each lens cross-sectional view, the dotted line indicating the movement trajectory of the sixth lens unit B6 indicates the movement trajectory for correcting the image plane variation accompanying zooming from the wide-angle end to the telephoto end when focusing on a short-distance object. Represents.

  The sixth lens unit B6 moves toward the object side during zooming from the wide-angle end to the telephoto end. By moving the sixth lens unit B6 having negative refractive power toward the object side during zooming, the focus sensitivity of the sixth lens unit B6 can be increased. As a result, the amount of movement of the sixth lens unit B6 during focusing is reduced. can do. As a result, it is possible to reduce the size of the entire zoom lens system and suppress the occurrence of image plane fluctuations due to focusing.

  In the zoom lenses of Examples 2 to 8, the sixth lens unit B6 moves toward the object side from the wide-angle end toward the telephoto end during zooming when focusing on an infinite object, and before the telephoto end. After moving to the image side once, move to the object side again. By moving the sixth lens unit B6 to the image side before the telephoto end, it is possible to suppress the occurrence of image plane fluctuations near the telephoto end.

  In the zoom lens of each embodiment, image blur correction is performed by moving the second lens unit B2 so as to have a component perpendicular to the optical axis. Note that image blur correction may be performed by moving the fourth lens unit B4 so as to have a component perpendicular to the optical axis.

In each embodiment, the focus sensitivity of the sixth lens unit B6 at the wide-angle end when focusing at infinity is ESW, and the sixth lens unit B6 at the telephoto end when focusing at infinity. , And the focal length of the sixth lens unit B6 is f6. When the amount of movement of the sixth lens unit B6 during zooming from the wide-angle end to the telephoto end when focusing on infinity is M6,
3.50 <EST / ESW <10.00 (1)
−5.00 <f6 / M6 <−0.90 (2)
The following conditional expression is satisfied.

  Here, the focus sensitivity is a parameter indicating a ratio between the amount of movement of the focus group in the optical axis direction and the amount of movement of the imaging position due to the movement of the focus group.

The focus sensitivity ES of the focus group is
ES = (1-β ² ) × βr ²
It is shown. β is the lateral magnification of the focus group, and βr means the lateral magnification of the optical system disposed on the image side of the focus group.

  The amount of movement is the difference in position on the optical axis of each lens group at the wide-angle end and the telephoto end, and the sign of the amount of movement is positive when it is located on the object side at the telephoto end compared to the wide-angle end, Negative when located on the image side.

  Conditional expression (1) defines the ratio between the focus sensitivity of the sixth lens unit B6 at the wide-angle end and the focus sensitivity of the sixth lens unit B6 at the telephoto end.

  When the lower limit of conditional expression (1) is exceeded and the focus sensitivity of the sixth lens unit B6 at the telephoto end decreases, the amount of movement of the sixth lens unit B6 during focusing from infinity to the closest distance increases, and the entire system This is not preferable because it leads to an increase in size. Further, if the sensitivity of the sixth lens unit B6 at the wide-angle end becomes higher than the lower limit of the conditional expression (1), image plane fluctuations are likely to occur due to errors in position control of the focus unit. Absent.

  If the upper limit of conditional expression (1) is exceeded and the focus sensitivity of the sixth lens unit B6 at the telephoto end increases, image plane fluctuations are likely to occur due to focus group position control errors, which is not preferable. If the upper limit of conditional expression (1) is exceeded and the focus sensitivity of the sixth lens unit B6 at the wide angle end decreases, the amount of movement of the sixth lens unit B6 during focusing from infinity to the closest distance increases. This is not preferable because it increases the size of the entire system. Furthermore, if the amount of movement of the focus lens group during focusing is increased, a large variation in field curvature due to focusing is undesirable.

  Conditional expression (2) indicates the ratio between the focal length f6 of the sixth lens unit B6 and the amount of movement M6 of the sixth lens unit during zooming from the wide-angle end to the telephoto end when focusing on infinity. It is a defined conditional expression.

  When the lower limit of conditional expression (2) is exceeded and the focal length of the sixth lens unit B6 increases, the focus sensitivity of the sixth lens unit B6 at the wide-angle end decreases. As a result, the amount of movement of the sixth lens unit B6 at the time of focusing from infinity to a close distance becomes large, leading to an increase in the size of the entire system, which is not preferable. Furthermore, if the amount of movement of the focus lens group during focusing is increased, a large variation in field curvature due to focusing is undesirable.

  If the upper limit of conditional expression (2) is exceeded and the focal length of the sixth lens unit B6 is shortened, the refractive power of the sixth lens unit B6 becomes too strong, resulting in a large variation in field curvature during focusing. It is not preferable.

  In each embodiment, as described above, each element is appropriately set so as to satisfy the conditional expressions (1) and (2). Accordingly, it is possible to obtain a zoom lens that is compact and has high optical performance during focusing at each subject distance.

In each embodiment, it is preferable to set the numerical ranges of conditional expressions (1) and (2) as follows.
3.60 <EST / ESW <8.00 (1a)
-2.50 <f6 / M6 <-0.92 (2a)

More preferably, the numerical ranges of the conditional expressions (1) and (2) are set as follows.
3.70 <EST / ESW <6.00 (1b)
−2.00 <f6 / M6 <−0.93 (2b)

Furthermore, in each embodiment, it is more preferable to satisfy one or more of the following conditional expressions.
0.10 <M6 / LT <0.25 (3)
0.50 <Rr / M6 <9.00 (4)
−30.0 <M1 / M2 <−2.0 (5)
0.030 <SKW / ft <0.090 (6)
0.030 <SKT / LT <0.280 (7)
−1.20 <ESW <−0.50 (8)
−4.50 <EST <−1.70 (9)
−0.30 <f6 / ft <−0.10 (10)
−0.90 <f6n / f6p <−0.40 (11)

  Here, let LT be the thickness on the optical axis of the entire zoom lens system at the telephoto end, and let Rr be the radius of curvature of the lens surface on the image side of the lens disposed closest to the image side in the sixth lens unit B6. Further, the amount of movement of the first lens unit B1 during zooming from the wide-angle end to the telephoto end is M1, and the amount of movement of the second lens unit B2 during zooming from the wide-angle end to the telephoto end is M2. Further, the back focus of the zoom lens at the wide angle end is SKW, the back focus of the zoom lens at the telephoto end is SKT, and the focal length of the entire system at the telephoto end is ft. Further, the focal length of the positive lens included in the sixth lens unit B6 is f6p, and the focal length of the negative lens included in the sixth lens unit B6 is f6n.

  The thickness on the optical axis of the entire zoom lens system indicates the distance on the optical axis from the lens surface closest to the object side of the zoom lens to the lens surface closest to the image side of the zoom lens. Further, the back focus is the distance from the lens surface closest to the image side of the zoom lens to the image plane, expressed as an air-converted length.

  Conditional expression (3) indicates the amount of movement M6 of the sixth lens group during zooming from the wide-angle end to the telephoto end when focusing on infinity, and on the optical axis of the entire zoom lens system at the telephoto end. It is the conditional expression which prescribed | regulated ratio of thickness LT.

  When the lower limit of conditional expression (3) is exceeded and the amount of movement B6 of the sixth lens unit B6 during zooming decreases, the focus sensitivity of the sixth lens unit B6 at the telephoto end decreases. As a result, the amount of movement of the sixth lens unit B6 at the time of focusing from infinity to the closest distance increases, which leads to an increase in the size of the entire system, which is not preferable. Furthermore, if the amount of movement of the focus lens group during focusing is increased, a large variation in field curvature due to focusing is undesirable.

  If the movement amount B6 of the sixth lens unit B6 in zooming increases beyond the upper limit of conditional expression (3), the focus sensitivity of the sixth lens unit B6 at the telephoto end increases. As a result, image plane fluctuations are likely to occur due to focus group position control errors, which is not preferable.

  Conditional expression (4) indicates that the radius of curvature Rr of the lens surface on the image side of the lens disposed closest to the image side in the sixth lens unit B6 and the telephoto lens from the wide-angle end when focused on infinity. It is a conditional expression that defines the ratio of the moving amount M6 of the sixth lens unit B6 in zooming toward the end.

  When the curvature radius Rr becomes shorter than the lower limit value of the conditional expression (4), the light beam reflected by the imaging surface is re-reflected by the lens surface having the curvature radius Rr, and a ghost or the like is likely to occur in the captured image. It is not preferable.

  If the curvature radius Rr becomes longer than the upper limit value of the conditional expression (4), it is difficult to sufficiently correct the fluctuation of the field curvature with respect to the change of the object distance at the telephoto end.

  Conditional expression (5) defines the ratio between the amount of movement M1 of the first lens unit B1 during zooming from the wide-angle end to the telephoto end and the amount of movement M2 of the second lens unit B2 during zooming from the wide-angle end to the telephoto end. Conditional expression.

  If the amount of movement of the first lens unit B1 exceeds the lower limit value of the conditional expression (5), the total lens length at the telephoto end increases, which increases the size of the optical system, which is not preferable. Further, when the amount of movement of the second lens unit B2 becomes smaller than the lower limit value of the conditional expression (5), the zooming action of the second lens unit B2 is reduced, and the zoom lens can be increased in magnification. Since it becomes difficult, it is not preferable.

  If the upper limit of conditional expression (5) is exceeded and the amount of movement of the first lens unit B1 becomes small, the distance between the first lens unit B1 and the aperture stop SP at the wide-angle end becomes too large and the effective diameter of the front lens increases. Therefore, it is not preferable.

  Conditional expression (6) is a conditional expression that regulates the ratio between the back focus SKW of the zoom lens at the wide-angle end and the focal length ft of the entire system at the telephoto end.

  When the lower limit of conditional expression (6) is exceeded and the back focus SKW of the zoom lens at the wide-angle end becomes short, the focus sensitivity at the wide-angle end becomes low. As a result, the amount of movement of the sixth lens unit B6 at the time of focusing from infinity to a close distance becomes large, leading to an increase in the size of the entire system, which is not preferable.

  When the back focus SKW of the zoom lens at the wide-angle end becomes longer than the upper limit value of conditional expression (6), the movement amounts of the third lens group B3, the fourth lens group B4, and the fifth lens group B5 during zooming are increased. Get smaller. As a result, it is difficult to realize a high magnification of the zoom lens, which is not preferable.

  Conditional expression (7) is a conditional expression that defines the ratio of the back focus SKT of the zoom lens at the telephoto end to the thickness LT on the optical axis of the entire zoom lens system at the telephoto end.

  When the lower limit of conditional expression (7) is exceeded and the back focus SKT of the zoom lens at the telephoto end becomes short, the focus sensitivity at the telephoto end becomes low. As a result, the amount of movement of the sixth lens unit B6 at the time of focusing from infinity to a close distance becomes large, leading to an increase in the size of the entire system, which is not preferable.

  If the upper limit of conditional expression (7) is exceeded and the back focus SKT of the zoom lens at the telephoto end increases, the focus sensitivity at the telephoto end increases. As a result, image plane fluctuations are likely to occur due to focus group position control errors, which is not preferable.

  Conditional expression (8) is a conditional expression that defines the focus sensitivity ESW of the sixth lens unit B6 at the wide-angle end when focusing on infinity.

  When the upper limit of conditional expression (8) is exceeded and the focus sensitivity ESW of the sixth lens unit B6 at the wide-angle end decreases, the amount of movement of the sixth lens unit B6 during focusing from infinity to the closest distance increases. This is not preferable because it increases the size of the entire system.

  If the lower limit of conditional expression (8) is exceeded and the focus sensitivity ESW of the sixth lens unit B6 at the wide-angle end increases, image plane fluctuations are likely to occur due to focus group position control errors, which is preferable. Absent.

  Conditional expression (9) is a conditional expression that defines the focus sensitivity EST of the sixth lens unit B6 at the telephoto end when focusing on infinity.

  When the upper limit of conditional expression (9) is exceeded and the focus sensitivity EST of the sixth lens unit B6 at the telephoto end decreases, the amount of movement of the sixth lens unit B6 during focusing from infinity to the closest distance increases. This is not preferable because it increases the size of the entire system.

  If the lower limit of conditional expression (9) is exceeded and the focus sensitivity EST of the sixth lens unit B6 at the telephoto end increases, image plane fluctuations are more likely to occur due to focus group position control errors, which is preferable. Absent.

  Conditional expression (10) is a conditional expression that defines a ratio between the focal length f6 of the sixth lens unit B6 and the focal length ft of the entire system at the telephoto end.

  If the upper limit of conditional expression (10) is exceeded and the focal length f6 of the sixth lens unit B6 becomes shorter, the refractive power of the sixth lens unit B6 becomes too strong. As a result, many aberration fluctuations occur during focusing, which is not preferable.

  If the lower limit of conditional expression (10) is exceeded and the focal length f6 of the sixth lens unit B6 becomes longer, the refractive power of the sixth lens unit B6 becomes too weak. As a result, the zooming action of the sixth lens unit B6 is reduced, and it is difficult to realize a high zoom lens magnification.

  Conditional expression (11) is a conditional expression that defines the ratio between the focal length f6p of the positive lens included in the sixth lens group B6 and the focal length f6n of the negative lens included in the sixth lens group B6.

  When the upper limit of conditional expression (11) is exceeded and the focal length f6n of the negative lens included in the sixth lens group B6 becomes shorter, the refractive power of the negative lens included in the sixth lens group B6 becomes too strong. The achromatic action as the entire sixth lens unit B6 is lowered, and it is difficult to satisfactorily correct lateral chromatic aberration over the entire zoom range, which is not preferable.

  If the lower limit of conditional expression (11) is exceeded and the focal length f6n of the negative lens included in the sixth lens unit B6 becomes longer, the refractive power of the negative lens included in the sixth lens unit B6 becomes too weak. As a result, the refractive power of the sixth lens unit B6 becomes weak, and the focus sensitivity of the sixth lens unit B6 at the wide angle end decreases. As a result, the amount of movement of the sixth lens unit B6 at the time of focusing from infinity to the closest distance increases, which leads to an increase in the size of the entire system, which is not preferable.

Preferably, the numerical ranges of the conditional expressions (3) to (11) are set as follows.
0.12 <M6 / LT <0.22 (3a)
0.55 <Rr / M6 <7.50 (4a)
−29.0 <M1 / M2 <−2.2 (5a)
0.031 <SKW / ft <0.075 (6a)
0.035 <SKT / LT <0.270 (7a)
−1.10 <ESW <−0.51 (8a)
-4.20 <EST <-2.00 (9a)
−0.27 <f6 / ft <−0.11 (10a)
−0.80 <f6n / f6p <−0.43 (11a)

More preferably, the numerical ranges of the conditional expressions (3) to (11) are set as follows.
0.15 <M6 / LT <0.20 (3b)
0.60 <Rr / M6 <5.00 (4b)
−28.0 <M1 / M2 <−2.3 (5b)
0.031 <SKW / ft <0.050 (6b)
0.040 <SKT / LT <0.260 (7b)
−1.00 <ESW <−0.51 (8b)
-4.00 <EST <-2.30 (9b)
−0.25 <f6 / ft <−0.12 (10b)
−0.75 <f6n / f6p <−0.45 (11b)

  Next, the configuration of each lens group will be described.

  In the zoom lens of each embodiment, the first lens unit B1 includes a negative lens, a positive lens, and a positive lens in order from the object side to the image side. By arranging a plurality of positive lenses in the first lens unit B1, the radius of curvature of the lens surface of each positive lens can be increased. As a result, coma at the telephoto end can be corrected well.

  In the zoom lens of each embodiment, the second lens unit B2 includes a negative lens, a negative lens, and a positive lens in order from the object side to the image side. By configuring the second lens unit B2 to include at least two negative lenses and a positive lens, it is possible to favorably correct curvature of field and lateral chromatic aberration at the wide angle end. In the zoom lens of Example 5, the negative lens and the positive lens included in the second lens group B2 are cemented to constitute a cemented lens. Manufacturing sensitivity can be reduced by joining the negative lens and the positive lens.

  In the zoom lenses of Examples 1 to 4 and Examples 6 to 8, the second lens group B2 is configured by three single lenses. The field curvature at the wide-angle end is corrected well by appropriately setting the air gap between the negative lens and the positive lens arranged second from the object side.

  In the zoom lenses of Examples 1 to 5 and Example 8, the third lens unit B3 includes a positive lens and a cemented lens in which a positive lens and a negative lens are cemented in order from the object side to the image side. In the zoom lenses of Examples 6 and 7, the third lens unit B3 includes a positive lens, a cemented lens in which a positive lens and a negative lens are cemented, and a positive lens in order from the object side to the image side. By disposing a plurality of positive lenses in the third lens group B3, it is possible to share the positive refractive power among the plurality of positive lenses. As a result, the manufacturing sensitivity of each positive lens can be reduced. In addition, by arranging two positive lenses in succession from the object side, the principal point position of the third lens unit B3 can be moved to the object side. As a result, the distance between the second lens unit B2 and the third lens unit B3 at the telephoto end can be reduced, and the zoom lens can be further increased in magnification.

  In the zoom lens of each embodiment, the fourth lens unit B4 includes a cemented lens in which a negative lens and a positive lens are cemented in order from the object side to the image side.

  In the zoom lenses of Examples 1, 2, and 8, the fifth lens unit B5 includes a positive lens and a cemented lens in which a negative lens and a positive lens are cemented in order from the object side to the image side. In the zoom lenses of Examples 3 to 7, the fifth lens unit B5 includes, in order from the object side to the image side, a positive lens, a cemented lens in which a negative lens and a positive lens are cemented, and a positive lens. By arranging a plurality of positive lenses in the fifth lens group B5, it is possible to share the positive refractive power among the plurality of positive lenses. As a result, the manufacturing sensitivity of each positive lens can be reduced.

  In the zoom lens of each embodiment, the sixth lens unit B6 includes a negative lens and a positive lens in order from the object side to the image side. In the zoom lenses of Examples 5, 6 and 8, the sixth lens unit B6 is composed of a cemented lens in which a negative lens and a positive lens are cemented. By configuring the sixth lens group B6, which is the focus group, with two lenses, the focus group can be reduced in weight, and as a result, high-speed focusing can be realized.

  In the zoom lens according to Example 8, the seventh lens unit B7 includes one positive lens.

  Next, numerical examples 1 to 8 corresponding to the first to eighth embodiments of the present invention will be described. In each numerical example, i indicates the order of optical surfaces from the object side. ri is the radius of curvature of the i-th optical surface (i-th surface), di is the distance between the i-th surface and the i + 1-th surface, and ndi and νdi are the refractions of the material of the i-th optical member with respect to the d-line, respectively. Indicates the rate and Abbe number.

When K is an eccentricity, A4, A6, A8, A10, A12, and A14 are aspherical coefficients, and the displacement in the optical axis direction at the position of the height h from the optical axis is x based on the surface vertex, The aspheric shape is
x = (h ² / R) / [1+ [1− (1 + K) (h / R) ² ] ^1/2 ] + A4h ⁴ + A6h ⁶ + A8h ⁸ + A10h ¹⁰ + A12h ¹² + A14h ¹⁴
Is displayed. Where R is the paraxial radius of curvature. The display of “e-Z” means “10 ^−Z ”.

  In each embodiment, the back focus (BF) represents the distance from the surface closest to the image side of the lens system to the image surface by an air conversion length. Table 1 shows the correspondence with the above-described conditional expressions in each numerical example.

  It should be noted that the effective image circle diameter at the wide-angle end (image circle diameter) can be made smaller than the effective image circle diameter at the telephoto end. This is because the barrel-shaped distortion that tends to occur on the wide-angle side can be corrected by enlarging the image by image processing.

[Numerical Example 1]
Unit mm
Surface data surface number rd nd νd Effective diameter
1 110.895 1.35 1.83400 37.2 41.60
2 55.931 5.11 1.49700 81.5 40.20
3 -598.618 0.05 39.90
4 56.778 4.01 1.49700 81.5 38.30
5 572.173 (variable) 37.80
6 349.604 0.80 1.88300 40.8 25.70
7 14.585 5.76 20.50
8 -45.193 0.60 1.59522 67.7 20.30
9 41.026 0.10 20.00
10 24.111 2.17 1.95906 17.5 20.10
11 58.474 (variable) 19.80
12 (Aperture) ∞ 0.44 10.21
13 32.039 1.70 1.66672 48.3 10.40
14 -37.195 0.10 10.40
15 28.383 1.97 1.49700 81.5 10.20
16 -26.617 0.50 1.95375 32.3 9.90
17 961.626 (variable) 9.80
18 * -23.163 0.40 1.85135 40.1 9.40
19 23.358 1.37 2.00069 25.5 9.80
20 2047.136 (variable) 9.90
21 * 210.013 1.38 1.55332 71.7 10.30
22 -28.703 0.20 10.60
23 25.622 0.55 2.00069 25.5 11.00
24 14.523 2.47 1.59522 67.7 10.90
25 -28.859 (variable) 11.00
26 43.167 0.40 1.85135 40.1 10.60
27 * 11.097 1.67 10.40
28 13.736 2.00 1.85478 24.8 11.70
29 22.435 (variable) 11.50
30 ∞ 0.80 1.51633 64.1 20.00
31 ∞ 0.80 20.00
Image plane ∞
Aspheric data 18th surface
K = 4.36091e + 000 A 4 = 5.02858e-005 A 6 = 2.18165e-007 A 8 = 2.08189e-009
21st page
K = 2.59255e + 002 A 4 = -4.34755e-005 A 6 = -8.50437e-010 A 8 = 2.26733e-009 A10 = -2.15037e-011
27th page
K = 0.00000e + 000 A 4 = -1.53571e-005 A 6 = -3.00635e-007 A 8 = 1.98129e-009
Various data Zoom ratio 23.24
Wide angle Medium telephoto focal length 9.06 24.29 210.68
F number 2.88 4.27 5.88
Half angle of view 36.50 18.00 2.14
Image height 6.71 7.89 7.89
Total lens length 107.05 114.72 155.51
BF 9.18 22.00 38.71
d 5 0.96 18.67 69.38
d11 38.85 19.93 1.11
d17 1.15 5.41 9.48
d20 11.04 5.93 1.00
d25 10.48 7.41 0.46
d29 7.85 20.68 37.38

[Numerical Example 2]
Unit mm
Surface data surface number rd nd νd Effective diameter
1 96.566 1.35 1.83400 37.2 40.40
2 50.595 4.90 1.49700 81.5 39.30
3 -3546.014 0.05 39.20
4 53.771 3.89 1.49700 81.5 38.50
5 693.212 (variable) 38.30
6 314.206 0.80 1.88300 40.8 24.90
7 13.450 5.62 19.60
8 -46.178 0.60 1.59522 67.7 19.40
9 34.603 0.10 19.20
10 21.619 2.78 1.95906 17.5 19.40
11 48.536 (variable) 18.80
12 (Aperture) ∞ 0.44 10.76
13 27.876 1.95 1.69350 53.2 11.00
14 -30.149 0.10 11.00
15 59.916 1.75 1.49700 81.5 10.70
16 -17.663 0.50 1.88300 40.8 10.60
17 1669.428 (variable) 10.50
18 * -28.501 0.40 1.85135 40.1 11.10
19 56.748 1.28 1.84666 23.8 11.40
20 -117.508 (variable) 11.60
21 * 254.900 1.29 1.55332 71.7 12.70
22 -40.366 0.20 12.90
23 22.262 0.55 2.00069 25.5 13.50
24 14.725 3.10 1.53775 74.7 13.30
25 -31.313 (variable) 13.40
26 48.603 0.40 1.85135 40.1 12.00
27 * 12.964 1.67 11.70
28 14.183 1.38 1.85478 24.8 12.90
29 22.627 (variable) 12.70
30 ∞ 0.80 1.51633 64.1 20.00
31 ∞ 0.80 20.00
Image plane ∞
Aspheric data 18th surface
K = 6.25101e + 000 A 4 = 3.54171e-005 A 6 = 2.24129e-007 A 8 = 2.44121e-011
21st page
K = 7.15649e + 002 A 4 = -3.07567e-005 A 6 = 1.20737e-007 A 8 = -3.60067e-009 A10 = 2.91527e-011
27th page
K = 0.00000e + 000 A 4 = -5.21526e-007 A 6 = 7.85978e-008 A 8 = -1.38700e-009
Various data Zoom ratio 23.63
Wide angle Medium Telephoto focal length 9.06 22.84 214.16
F number 2.77 4.11 5.88
Half angle of view 36.50 19.05 2.11
Image height 6.71 7.89 7.89
Total lens length 110.52 119.62 161.78
BF 7.95 21.46 38.66
d 5 0.96 16.53 66.61
d11 35.75 19.75 2.28
d17 1.12 8.83 16.45
d20 16.12 8.41 0.78
d25 13.24 9.27 1.61
d29 6.62 20.13 37.33

[Numerical Example 3]
Unit mm
Surface data surface number rd nd νd Effective diameter
1 103.058 1.35 1.83400 37.2 39.72
2 50.327 5.03 1.49700 81.5 36.68
3 -340.744 0.05 35.94
4 50.252 4.05 1.49700 81.5 35.57
5 632.909 (variable) 35.25
6 -280.705 0.80 1.88300 40.8 23.16
7 13.669 5.29 18.42
8 -32.710 0.60 1.59522 67.7 18.23
9 38.952 0.10 18.06
10 23.644 2.14 1.95906 17.5 18.24
11 68.861 (variable) 17.96
12 (Aperture) ∞ 0.44 10.40
13 30.771 1.81 1.71300 53.9 10.67
14 -37.534 0.10 10.72
15 39.970 2.09 1.49700 81.5 10.61
16 -21.269 0.50 1.91082 35.3 10.42
17 -350.267 (variable) 10.40
18 * -26.879 0.40 1.85135 40.1 10.15
19 26.409 1.54 1.84666 23.8 10.48
20 -264.396 (variable) 10.70
21 * 303.936 1.80 1.55332 71.7 11.29
22 -20.787 3.08 11.60
23 36.078 0.55 2.00069 25.5 12.46
24 15.313 2.38 1.51742 52.4 12.36
25 -249.322 0.10 12.54
26 16.634 2.23 1.48749 70.2 12.90
27 995.538 (variable) 12.79
28 55.866 0.40 1.85135 40.1 11.39
29 * 10.931 1.67 11.10
30 14.606 1.73 1.85478 24.8 12.20
31 29.786 (variable) 12.11
32 ∞ 0.80 1.51633 64.1 20.00
33 ∞ 0.80 20.00
Image plane ∞
Aspheric data 18th surface
K = 4.73749e + 000 A 4 = 3.10790e-005 A 6 = 2.08636e-007 A 8 = -1.16125e-009
21st page
K = 6.02957e + 002 A 4 = -2.23567e-005 A 6 = -5.02842e-009 A 8 = -2.74888e-010 A10 = 1.22772e-011
29th page
K = 0.00000e + 000 A 4 = -2.55578e-005 A 6 = -2.46916e-007 A 8 = -2.06719e-009
Various data Zoom ratio 23.66
Wide angle Medium Telephoto focal length 9.06 21.45 214.45
F number 2.86 4.23 5.88
Half angle of view 36.50 20.19 2.11
Image height 6.71 7.89 7.89
Total lens length 106.25 113.62 149.99
BF 10.29 21.39 35.35
d 5 0.96 13.10 59.22
d11 32.91 19.51 1.11
d17 1.07 7.89 12.86
d20 12.28 5.47 0.49
d27 8.21 5.75 0.43
d31 8.96 20.06 34.02

[Numerical Example 4]
Unit mm
Surface data surface number rd nd νd Effective diameter
1 83.481 1.40 1.91082 35.3 39.90
2 48.302 5.02 1.49700 81.5 37.80
3 -857.253 0.05 37.50
4 46.749 3.97 1.49700 81.5 35.90
5 329.418 (variable) 35.60
6 -14830.673 0.85 1.83481 42.7 22.40
7 13.128 5.15 17.50
8 * -25.862 0.65 1.59201 67.0 17.30
9 29.125 0.10 16.80
10 23.330 1.81 1.95906 17.5 16.80
11 64.464 (variable) 16.60
12 ∞ 0.44 10.31
13 1193.724 1.49 1.88300 40.8 10.50
14 -37.558 0.10 13.00
15 19.866 2.90 1.49700 81.5 13.00
16 -28.640 0.50 2.00069 25.5 13.00
17 -79.177 0.50 13.00
18 (Aperture) ∞ (Variable) 10.44
19 * -23.577 0.40 1.85135 40.1 12.10
20 22.470 2.25 1.76182 26.5 13.50
21 -62.619 (variable) 13.50
22 * -368.933 1.78 1.55332 71.7 13.50
23 -22.821 0.10 13.80
24 42.836 0.55 2.00 100 29.1 14.20
25 14.009 2.99 1.51742 52.4 14.00
26 1076.589 0.10 14.40
27 18.374 3.24 1.48749 70.2 15.20
28 -51.882 (variable) 15.20
29 115.205 0.40 1.85135 40.1 12.50
30 14.149 0.90 13.50
31 15.208 1.79 1.85478 24.8 14.00
32 29.953 (variable) 14.00
33 ∞ 0.80 1.51633 64.1 20.00
34 ∞ 0.80 20.00
Image plane ∞
Aspheric data 8th surface
K = 3.35168e-001 A 4 = 6.88908e-006 A 6 = 1.19970e-009 A 8 = -3.94595e-010
19th page
K = 2.88079e + 000 A 4 = 4.26612e-005 A 6 = 1.40660e-007 A 8 = 5.28691e-010
22nd page
K = 0.00000e + 000 A 4 = -2.07402e-005 A 6 = 1.30685e-007 A 8 = -1.75763e-009 A10 = 1.16105e-011
Various data Zoom ratio 23.53
Wide angle Medium telephoto focal length 9.06 20.83 213.31
F number 2.88 4.04 5.77
Half angle of view 36.50 20.74 2.12
Image height 6.71 7.89 7.89
Total lens length 103.06 113.14 150.66
BF 8.54 22.13 37.61
d 5 0.96 13.74 58.19
d11 29.68 17.49 1.06
d18 1.63 5.84 12.88
d21 11.59 7.38 0.34
d28 10.96 6.86 0.87
d32 7.21 20.80 36.28

[Numerical Example 5]
Unit mm
Surface data surface number rd nd νd Effective diameter
1 104.304 1.40 1.91082 35.3 39.90
2 49.610 5.34 1.49700 81.5 39.00
3 -618.482 0.05 38.90
4 48.380 4.42 1.59282 68.6 38.20
5 378.423 (variable) 37.80
6 1516.485 0.85 1.83481 42.7 21.90
7 13.712 5.26 17.40
8 * -22.744 0.70 1.58313 59.4 16.90
9 18.204 2.25 1.92286 18.9 16.30
10 60.634 (variable) 16.10
11 ∞ 0.44 10.67
12 67.003 1.90 1.74400 44.8 13.00
13 -35.477 0.10 13.00
14 19.879 3.09 1.49700 81.5 13.00
15 -26.379 0.50 2.00069 25.5 13.00
16 -84.383 0.50 13.00
17 (Aperture) ∞ (Variable) 10.81
18 * -30.001 0.50 1.85135 40.1 12.10
19 19.675 1.71 1.84666 23.8 12.70
20 98.984 (variable) 12.90
21 -563.301 1.89 1.55332 71.7 13.60
22 * -23.236 0.10 13.90
23 38.558 0.55 2.00 100 29.1 14.40
24 13.636 3.88 1.51742 52.4 14.40
25 -65.576 0.10 14.90
26 16.996 3.01 1.51633 64.1 15.90
27 -417.181 (variable) 15.80
28 * -150.202 0.50 1.85135 40.1 12.70
29 10.556 3.57 1.69895 30.1 12.80
30 105.702 (variable) 12.80
31 ∞ 0.80 1.51633 64.1 20.00
32 ∞ 0.80 20.00
Image plane ∞
Aspheric data 8th surface
K = -6.47278e-001 A 4 = -3.03590e-006 A 6 = 8.80826e-008 A 8 = -1.84165e-009 A10 = -1.43545e-012 A12 = 7.83336e-014
18th page
K = 1.78451e + 000 A 4 = 2.07490e-005 A 6 = -3.07891e-008 A 8 = 3.81579e-010 A10 = 1.11493e-011
22nd page
K = 0.00000e + 000 A 4 = 1.35911e-007 A 6 = 9.56796e-009 A 8 = -4.21073e-010 A10 = 2.32346e-012
28th page
K = 0.00000e + 000 A 4 = 7.19458e-006 A 6 = 1.48544e-007 A 8 = -7.70398e-010
Various data Zoom ratio 23.56
Wide angle Medium Telephoto focal length 9.06 21.04 213.60
F number 2.86 3.90 5.77
Half angle of view 36.50 20.56 2.12
Image height 6.71 7.89 7.89
Total lens length 105.18 115.00 152.44
BF 10.33 20.79 33.76
d 5 0.96 14.95 58.83
d10 29.07 16.63 1.51
d17 1.89 5.97 12.80
d20 12.19 8.11 1.28
d27 7.87 5.67 1.41
d30 9.00 19.47 32.43

[Numerical Example 6]
Unit mm
Surface data surface number rd nd νd Effective diameter
1 80.235 1.43 1.91082 35.3 39.80
2 46.958 5.35 1.49700 81.5 38.80
3 -4780.848 0.05 38.60
4 48.100 4.45 1.49700 81.5 37.60
5 496.735 (variable) 37.10
6 1544.553 0.80 1.83481 42.7 20.60
7 11.396 5.60 15.90
8 * -16.601 0.70 1.58313 59.4 15.50
9 38.732 0.20 15.40
10 30.555 1.90 1.94595 18.0 15.50
11 -435.264 (variable) 15.40
12 ∞ 0.10 11.08
13 * 21.856 2.10 1.85135 40.1 13.00
14 * -315.973 0.08 13.00
15 25.200 2.00 1.69350 53.2 13.00
16 -96.051 0.50 2.00 100 29.1 13.00
17 18.552 0.57 12.80
18 34.234 2.10 1.60311 60.6 13.00
19 -34.234 0.25 13.00
20 ∞ (variable) 10.20
21 * -30.953 0.50 1.85135 40.1 12.60
22 18.668 1.80 1.80518 25.5 13.50
23 127.298 (variable) 13.50
24 147.131 2.00 1.59282 68.6 14.10
25 -28.677 0.10 14.50
26 39.035 0.60 2.00 100 29.1 15.10
27 14.129 4.05 1.51742 52.4 15.00
28 -59.721 0.10 15.50
29 16.974 3.55 1.48749 70.2 16.70
30 -136.987 (variable) 16.60
31 * 587.265 0.60 1.85135 40.1 13.10
32 10.445 3.45 1.69895 30.1 14.00
33 51.970 (variable) 14.00
34 ∞ 0.80 1.51633 64.1 20.00
35 ∞ 0.80 20.00
Image plane ∞
Aspheric data 8th surface
K = -2.88261e-001 A 4 = 5.18781e-006 A 6 = 3.53315e-007 A 8 = -1.05067e-008 A10 = 8.98958e-011
A12 = -1.09215e-013 A14 = -1.59647e-015
Side 13
K = -1.48216e + 000 A 4 = 6.19282e-006 A 6 = 9.61653e-009 A 8 = 7.61929e-010 A10 = -7.64441e-012
14th page
K = 0.00000e + 000 A 4 = 8.37711e-006
21st page
K = 3.92664e + 000 A 4 = 2.64469e-005 A 6 = -2.16176e-008 A 8 = 4.35581e-009 A10 = -5.19006e-011
No. 31
K = 0.00000e + 000 A 4 = 4.85523e-006 A 6 = 1.67665e-007 A 8 = -2.66552e-009 A10 = 2.25666e-011
Various data Zoom ratio 23.54
Wide angle Medium telephoto focal length 9.06 24.18 213.40
F number 2.88 4.41 5.77
Half angle of view 36.50 18.07 2.12
Image height 6.71 7.89 7.89
Total lens length 104.29 119.22 155.38
BF 10.45 25.49 35.25
d 5 0.96 17.07 59.01
d11 28.33 15.88 0.35
d20 4.65 10.13 13.30
d23 9.53 4.05 0.88
d30 5.16 1.40 1.40
d33 9.13 24.16 33.92

[Numerical Example 7]
Unit mm
Surface data surface number rd nd νd Effective diameter
1 92.403 1.43 1.91082 35.3 44.80
2 54.584 5.65 1.49700 81.5 43.80
3 -2786.713 0.05 43.60
4 58.967 4.75 1.49700 81.5 43.20
5 895.648 (variable) 42.90
6 246.117 0.80 1.83481 42.7 20.60
7 11.282 5.60 15.90
8 * -16.380 0.70 1.55332 71.7 15.60
9 44.492 0.20 15.50
10 28.698 1.90 1.94595 18.0 15.60
11 268.856 (variable) 15.50
12 ∞ 0.10 11.32
13 * 24.995 2.10 1.85135 40.1 13.00
14 * -977.310 0.10 13.00
15 25.392 2.00 1.59282 68.6 13.00
16 -72.493 0.50 1.95375 32.3 13.00
17 19.961 0.57 12.80
18 30.079 2.10 1.60311 60.6 13.00
19 -34.578 0.25 13.00
20 ∞ (variable) 10.79
21 * -37.281 0.50 1.85135 40.1 13.70
22 18.602 1.80 1.80518 25.5 13.50
23 113.542 (variable) 13.50
24 120.814 2.00 1.59282 68.6 15.50
25 -39.650 0.10 15.90
26 47.079 0.60 2.00100 29.1 16.60
27 15.994 4.05 1.51742 52.4 16.60
28 -57.739 0.10 17.10
29 20.494 3.85 1.48749 70.2 18.60
30 -59.884 (variable) 18.60
31 * 307.004 0.60 1.85135 40.1 13.90
32 14.372 0.70 14.00
33 16.375 2.45 1.69895 30.1 14.00
34 122.844 (variable) 14.00
35 ∞ 0.80 1.51633 64.1 20.00
36 ∞ 0.80 20.00
Image plane ∞
Aspheric data 8th surface
K = -2.78544e-001 A 4 = 5.28812e-007 A 6 = 7.54464e-008 A 8 = 1.63509e-009 A10 = -2.01219e-010
A12 = 3.46155e-012 A14 = -2.09874e-014
Side 13
K = -1.92909e + 000 A 4 = 3.15119e-006 A 6 = 7.73188e-009 A 8 = -1.55140e-010 A10 = 4.48801e-012
14th page
K = 0.00000e + 000 A 4 = 1.48293e-007
21st page
K = 5.37431e + 000 A 4 = 1.38949e-005 A 6 = 2.07246e-007 A 8 = -2.78542e-009 A10 = 2.60718e-011
No. 31
K = 0.00000e + 000 A 4 = 1.06366e-005 A 6 = 2.16839e-008 A 8 = 5.38544e-010 A10 = -4.05043e-012
Various data Zoom ratio 28.25
Wide angle Medium telephoto focal length 9.06 22.79 256.07
F number 2.88 4.37 5.77
Half angle of view 36.50 19.09 1.76
Image height 6.71 7.89 7.89
Total lens length 111.00 128.46 179.57
BF 9.77 29.52 44.90
d 5 0.96 17.93 72.05
d11 29.15 17.29 0.33
d20 5.67 11.47 13.96
d23 10.80 3.91 1.12
d30 8.81 2.52 1.38
d34 8.45 28.19 43.57

[Numerical Example 8]
Unit mm
Surface data surface number rd nd νd Effective diameter
1 115.358 1.35 1.83400 37.2 40.40
2 55.871 5.10 1.49700 81.5 39.20
3 -339.992 0.05 39.00
4 52.911 4.00 1.49700 81.5 37.10
5 380.859 (variable) 36.50
6 576.733 0.80 1.88300 40.8 24.00
7 13.333 5.76 19.00
8 -38.290 0.60 1.59522 67.7 18.80
9 47.476 0.10 18.60
10 23.410 2.17 1.95906 17.5 18.80
11 55.657 (variable) 18.40
12 (Aperture) ∞ 0.44 10.99
13 73.201 1.50 1.83481 42.7 11.20
14 -50.757 0.10 11.30
15 15.203 2.20 1.49700 81.5 11.20
16 -84.688 0.50 1.95375 32.3 10.90
17 667.613 (variable) 10.80
18 * -36.095 0.40 1.85 135 40.1 10.00
19 12.607 1.37 2.00069 25.5 9.90
20 25.608 (variable) 9.70
21 -179.838 1.38 1.59522 67.7 10.30
22 -21.962 0.20 10.40
23 22.119 0.55 2.00069 25.5 10.20
24 11.703 2.47 1.59522 67.7 9.80
25 -51.471 (variable) 9.60
26 113.060 0.40 1.80 400 46.6 11.60
27 10.840 2.20 1.80610 33.3 11.60
28 17.349 (variable) 11.70
29 28.142 2.50 1.91082 35.3 18.20
30 1000.000 5.50 18.00
31 ∞ 0.80 1.51633 64.1 20.00
32 ∞ 0.80 20.00
Image plane ∞
Aspheric data 18th surface
K = 1.38937e + 001 A 4 = 3.31507e-005 A 6 = 2.64930e-007 A 8 = 1.42912e-009
Various data Zoom ratio 23.40
Wide angle Medium telephoto focal length 9.06 23.56 212.08
F number 2.88 4.32 5.81
Half angle of view 36.50 18.51 2.13
Image height 6.71 7.89 7.89
Total lens length 107.63 117.90 154.82
BF 6.83 6.83 6.83
d 5 0.96 17.97 65.88
d11 38.27 22.56 2.59
d17 1.13 2.50 3.20
d20 8.04 4.19 1.02
d25 13.11 12.22 8.65
d28 2.87 15.21 30.23

  Next, an embodiment of a digital still camera using a zoom lens as shown in each embodiment as a photographing optical system will be described with reference to FIG.

  In FIG. 17, reference numeral 20 denotes a camera body, and reference numeral 21 denotes a photographing optical system constituted by any zoom lens described in the first to eighth embodiments. Reference numeral 22 denotes an image sensor (photoelectric conversion element) 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 formed on the image sensor 22.

  Thus, by applying the zoom lens of the present invention to an imaging apparatus such as a digital still camera, it is possible to obtain an imaging apparatus that is compact and has high optical performance during focusing at each subject distance.

B1 1st lens group B2 2nd lens group B3 3rd lens group B4 4th lens group B5 5th lens group B6 6th lens group B7 7th lens group SP Diaphragm GB Glass block IP Image surface

Claims (17)

A first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, and a fourth lens group having a negative refractive power, which are arranged in order from the object side to the image side. A zoom lens having a fifth lens group having a positive refractive power and a sixth lens group having a negative refractive power, wherein an interval between adjacent lens groups is changed during zooming,
During focusing from infinity to close range, the sixth lens group moves,
The first lens group includes a negative lens, a positive lens, and a positive lens arranged in order from the object side to the image side,
ESW is the focus sensitivity of the sixth lens group when focusing on infinity at the wide angle end, and EST is the focus sensitivity of the sixth lens group when focusing on infinity at the telephoto end. The focal length of the sixth lens group is f6, and the amount of movement of the sixth lens group during zooming from the wide-angle end to the telephoto end when focusing on infinity is M6, and the sign of the amount of movement is the wide-angle end. When the telephoto end is located on the object side is positive and the image side is negative,
3.50 <EST / ESW <10.00
−5.00 <f6 / M6 <−0.90
A zoom lens satisfying the following conditional expression: When the distance on the optical axis from the most object-side lens surface to the most image-side lens surface of the zoom lens at the telephoto end is denoted by LT,
0.10 <M6 / LT <0.25
The zoom lens according to claim 1, wherein the following conditional expression is satisfied. When the radius of curvature of the lens surface on the image side of the lens arranged closest to the image side in the sixth lens group is Rr,
0.50 <Rr / M6 <9.00
The zoom lens according to claim 1, wherein the following conditional expression is satisfied. The sixth lens group, the zoom lens according to any one of claims 1 to 3, wherein the formed Rukoto from arranged positive lens on the image side of the negative lens and the negative lens. The amount of movement of the first lens group during zooming from the wide-angle end to the telephoto end is M1, the amount of movement of the second lens group during zooming from the wide-angle end to the telephoto end is M2, and the sign of the amount of movement is compared with that at the wide-angle end. positive when located on the object side at the telephoto end, when the negative when located on the image side,
-30.0 <M1 / M2 <-2.0
The zoom lens according to claim 1, wherein the following conditional expression is satisfied. When the back focus of the zoom lens at the wide angle end is SKW and the focal length of the entire system at the telephoto end is ft,
0.030 <SKW / ft <0.090
The zoom lens according to claim 1, wherein the following conditional expression is satisfied. When the distance on the optical axis from the lens surface closest to the object side of the zoom lens at the telephoto end to the lens surface closest to the image is LT, and the back focus of the zoom lens at the telephoto end is SKT,
0.030 <SKT / LT <0.280
The zoom lens according to claim 1, wherein the following conditional expression is satisfied. - 1.20 <ESW <-0.50
The zoom lens according to claim 1, wherein the following conditional expression is satisfied. - 4.50 <EST <-1.70
The zoom lens according to claim 1, wherein the following conditional expression is satisfied. When the focal length of the entire system at the telephoto end is ft,
−0.30 <f6 / ft <−0.10
The zoom lens according to claim 1, wherein the following conditional expression is satisfied. The sixth lens group includes a positive lens and a negative lens, and the focal length of the positive lens included in the sixth lens group is f6p, and the focal length of the negative lens included in the sixth lens group is f6n. ,
−0.90 <f6n / f6p <−0.40
The zoom lens according to claim 1, wherein the following conditional expression is satisfied. During zooming from the wide-angle end to the telephoto end when focusing on infinity, the sixth lens group, characterized in that after moving toward the object side, moves to the image side, moves to the object side after the The zoom lens according to any one of claims 1 to 11. A first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, and a fourth lens group having a negative refractive power, which are arranged in order from the object side to the image side. A zoom lens having a fifth lens group having a positive refractive power and a sixth lens group having a negative refractive power, wherein an interval between adjacent lens groups is changed during zooming,
During focusing from infinity to close range, the sixth lens group moves,
During zooming from the wide-angle end to the telephoto end when focusing on infinity, the sixth lens group moves to the image side after moving to the object side, and then moves to the object side.
ESW is the focus sensitivity of the sixth lens group when focusing on infinity at the wide angle end, and EST is the focus sensitivity of the sixth lens group when focusing on infinity at the telephoto end. The focal length of the sixth lens group is f6, and the amount of movement of the sixth lens group during zooming from the wide-angle end to the telephoto end when focusing on infinity is M6, and the sign of the amount of movement is the wide-angle end. When the telephoto end is located on the object side is positive and the image side is negative,
3.50 <EST / ESW <10.00
−5.00 <f6 / M6 <−0.90
A zoom lens satisfying the following conditional expression: The zoom lens is disposed in order from the object side to the image side, the first lens group, the second lens group, the third lens group, the fourth lens group, the fifth lens group, and the sixth lens. the zoom lens according to any of claims 1 to 13 characterized in that it is constituted from the group. The zoom lens is disposed in order from the object side to the image side, the first lens group, the second lens group, the third lens group, the fourth lens group, the fifth lens group, and the sixth lens. group, positive zoom lens according to any one of claims 1 to 13, that said to be composed of a seventh lens group having a refractive power. A first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, and a fourth lens group having a negative refractive power, which are arranged in order from the object side to the image side. A zoom lens comprising a fifth lens group having a positive refractive power, a sixth lens group having a negative refractive power, and a seventh lens group having a positive refractive power, wherein the interval between adjacent lens groups changes during zooming,
During focusing from infinity to close range, the sixth lens group moves,
ESW is the focus sensitivity of the sixth lens group when focusing on infinity at the wide angle end, and EST is the focus sensitivity of the sixth lens group when focusing on infinity at the telephoto end. The focal length of the sixth lens group is f6, and the amount of movement of the sixth lens group during zooming from the wide-angle end to the telephoto end when focusing on infinity is M6, and the sign of the amount of movement is the wide-angle end. When the telephoto end is located on the object side is positive and the image side is negative,
3.50 <EST / ESW <10.00
−5.00 <f6 / M6 <−0.90
A zoom lens satisfying the following conditional expression: A zoom lens according to any one of claims 1 to 16, an imaging apparatus characterized by having an imaging element for receiving an image formed by the zoom lens.

Images