JP2017151241A - Zoom lens and imaging device having the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a zoom lens small in size and having high optical performance as a whole and having a small change in an image magnification upon focusing, in which a focusing lens group is small in size.SOLUTION: The zoom lens includes, successively and sequentially arranged from an object side to an image side, a lens group Ln1 having a negative refractive power, a lens group Ln2 having a negative refractive power, a lens group Lp1 having a positive refractive power, and a rear group including at least one lens group, in which upon zooming, an interval between adjoining lens groups changes. Upon zooming, the lens group Ln1 and the lens group Lp1 move in the same trajectory; and upon focusing from infinity to a close range, the lens group Ln2 moves toward the object side.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a zoom lens and an image pickup apparatus having the same, and is suitable for an image pickup optical system used in an image pickup apparatus such as a digital camera, a video camera, a TV camera, a surveillance camera, and a silver salt film camera.

  An imaging optical system used in an imaging apparatus (camera) includes a standard shooting angle of view, and is demanded to be a small zoom lens with high resolution. In addition, when used in an imaging apparatus, it is desired that focusing can be performed at high speed and with high accuracy. On the other hand, recent single-lens reflex cameras are required to have a moving image shooting function and to be able to autofocus during moving image shooting. As a focus method for shooting a moving image, it is desired that a driving sound when driving a focus lens group is small and high-speed focusing is easy.

  In a zoom lens, the first lens group on the object side is generally large and tends to be heavy. For this reason, zoom lenses are known in which focusing is performed using a small and lightweight lens group disposed closer to the image side than the first lens group on the object side (Patent Documents 1 to 5).

  Patent Document 1 is composed of first to fifth lens groups having positive, negative, positive, negative, and positive refractive powers arranged in order from the object side to the image side. A changing zoom lens is disclosed. A zoom lens is disclosed in which the fourth lens group moves during focusing.

  Patent Document 2 is composed of first to sixth lens groups having positive, negative, positive, negative, positive, and positive refractive power arranged in order from the object side to the image side, and adjacent lens groups for zooming. A zoom lens with varying spacing is disclosed. A zoom lens is disclosed in which the fourth lens group moves during focusing.

  Patent Document 3 is composed of first to fifth lens groups having positive, negative, positive, negative, and positive refractive power arranged in order from the object side to the image side, and the distance between adjacent lens groups changes during zooming. A zoom lens is disclosed. A zoom lens in which the second lens group moves during focusing is disclosed.

  Patent Document 4 is composed of first to fifth lens groups having positive, negative, positive, negative, and positive refractive power arranged in order from the object side to the image side, and the interval between adjacent lens groups during zooming. A changing zoom lens is disclosed. A zoom lens is disclosed that divides the second lens group into two lens groups having negative refractive power and moves a part of the second lens group having negative refractive power during focusing.

  Patent Document 5 is composed of first to fourth lens groups having positive, negative, positive, and positive refractive power arranged in order from the object side to the image side, and the distance between adjacent lens groups changes during zooming. A zoom lens is disclosed. A zoom lens is disclosed that divides the second lens group into two lens groups having negative refractive power and moves while changing the distance between the two lens groups during focusing.

Japanese Patent Laying-Open No. 2015-72499 JP2013-011914A JP 2006-227526 A Japanese Patent Laid-Open No. 11-44848 JP 2008-292562 A

  There is a strong demand for a zoom lens used in an imaging apparatus that the entire lens system is small, that the focus lens group is small and light, that focusing can be performed at high speed, that the focusing lens is quiet, and that there is little variation in aberrations. In addition, if there is a change in image magnification (change in imaging magnification) at the time of focusing, the imaging screen changes, which is not preferable. Therefore, there is a demand for a small change in image magnification at the time of focusing.

  Generally, when the number of constituent lenses in the focus lens group is reduced in order to make the focus lens group small and light, the residual aberration of the focus lens group increases. For this reason, aberration fluctuations increase during focusing, and it becomes difficult to obtain good optical performance over the entire object distance from a long distance to a short distance.

  On the other hand, if the power (refractive power) of the focus lens group is reduced in order to reduce aberration fluctuations during focusing, the amount of movement during focusing increases, and the total lens length increases. In order to obtain a zoom lens that is compact in size, fast in focusing, quiet, and has little aberration variation and image magnification change during focusing, the number of lens groups, refractive power of each lens group, and lens configuration, etc. It is important to set up properly.

  For example, the zoom lens disclosed in Patent Document 1 described above facilitates quiet driving by using a small, lightweight fourth lens group as a focusing lens group. In Patent Document 1, when zooming from the wide-angle end to the telephoto end, the fourth lens group is driven so as to increase the distance from the third lens group, thereby obtaining a zooming effect.

  However, in Patent Document 1, it is necessary to leave an interval from the fifth lens unit by the amount that the focusing lens unit is driven at the telephoto end. As a result, the distance from the third lens group cannot be changed sufficiently, and it is difficult to reduce the size of the entire system while achieving a high zoom ratio. The zoom lens disclosed in Patent Document 2 facilitates quiet driving by using a small, lightweight fourth lens group as a focusing lens group. However, Patent Document 2 has a tendency that the image magnification change accompanying the focusing drive is large and the whole system is large.

  An object of the present invention is to provide a zoom lens in which a focusing lens group is small, an image magnification change during focusing is small, and the entire system is small and has high optical performance.

  The zoom lens according to the present invention includes a lens unit Ln1 having a negative refractive power, a lens unit Ln2 having a negative refractive power, a lens unit Lp1 having a positive refractive power, and one lens unit that are sequentially arranged from the object side to the image side. The zoom lens includes a rear group including the above-described lens groups, and the distance between adjacent lens groups changes during zooming, and the lens group Ln1 and the lens group Lp1 move along the same locus during zooming, and move from infinity to near The lens unit Ln2 moves to the object side during focusing to a distance.

  According to the present invention, it is possible to obtain a zoom lens having a small focusing lens group, a small change in image magnification during focusing, a small overall system, and high optical performance.

Cross-sectional view of a lens according to Example 1 of the present invention (A), (B) Longitudinal aberration diagrams at the wide-angle end and the telephoto end when focusing on infinity according to Example 1 of the present invention (A), (B) Longitudinal aberration diagrams at the wide-angle end and the telephoto end when focusing on the closest distance according to the first embodiment of the present invention Lens sectional view of Example 2 in the present invention (A), (B) Longitudinal aberration diagrams at the wide-angle end and the telephoto end when focusing on infinity according to Example 2 of the present invention (A), (B) Longitudinal aberration diagrams at the wide-angle end and the telephoto end when focusing on the closest distance according to the second embodiment of the present invention Lens sectional view of Example 3 in the present invention (A), (B) Longitudinal aberration diagrams at the wide-angle end and the telephoto end when focusing on infinity according to Example 3 of the present invention (A), (B) Longitudinal aberration diagrams at the wide-angle end and the telephoto end when focusing on the close range of Example 3 in the present invention Lens sectional view of Example 4 in the present invention (A), (B) Longitudinal aberration diagrams at the wide-angle end and the telephoto end when focusing on infinity according to Example 4 of the present invention (A), (B) Longitudinal aberration diagrams at the wide-angle end and the telephoto end when focusing on the closest distance according to the fourth embodiment of the present invention Lens sectional view of Example 5 in the present invention (A), (B) Longitudinal aberration diagrams at the wide-angle end and the telephoto end when focusing on infinity according to Example 5 of the present invention (A), (B) Longitudinal aberration diagrams at the wide-angle end and the telephoto end when focusing on the closest distance according to the fifth embodiment of the present invention Schematic diagram of main parts of an imaging apparatus of the present invention

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The zoom lens according to the present invention includes a lens unit Ln1 having a negative refractive power (reciprocal of focal length), a lens unit Ln2 having a negative refractive power, and a positive refractive power, which are sequentially arranged from the object side to the image side. The lens group Lp1 includes a rear group including one or more lens groups. The distance between adjacent lens units changes during zooming. The lens unit Ln1 and the lens unit Lp1 move along the same locus during zooming, and the lens unit Ln2 moves toward the object side during focusing from infinity to a short distance.

  FIG. 1 is a lens cross-sectional view at the wide angle end according to Embodiment 1 of the present invention. FIGS. 2A and 2B are aberration diagrams at the wide-angle end and the telephoto end when focusing on infinity according to the first embodiment. FIGS. 3A and 3B are aberration diagrams at the wide-angle end and the telephoto end when focusing on the closest distance according to the first embodiment. Embodiment 1 is a zoom lens having a zoom ratio of 9.67 and an F number of 4.10 to 6.40. Here, the close distance is, when numerical data to be described later is expressed in mm (which is the same hereinafter), 500 mm at the wide-angle end and 700 mm at the telephoto end from the image plane.

  FIG. 4 is a lens cross-sectional view at the wide angle end according to Embodiment 2 of the present invention. FIGS. 5A and 5B are aberration diagrams at the wide-angle end and the telephoto end when focusing on infinity according to the second embodiment. FIGS. 6A and 6B are aberration diagrams at the wide-angle end and the telephoto end when focusing on the closest distance according to the second embodiment. The second embodiment is a zoom lens having a zoom ratio of 9.67 and an F number of 4.10 to 6.40. Here, the closest distance is 700 mm at the wide-angle end and 700 mm at the telephoto end from the image plane.

  FIG. 7 is a lens cross-sectional view at the wide angle end according to Embodiment 3 of the present invention. FIGS. 8A and 8B are aberration diagrams at the wide-angle end and the telephoto end when focusing on infinity according to the third embodiment. FIGS. 9A and 9B are aberration diagrams at the wide-angle end and the telephoto end when focusing on the closest distance according to the third embodiment. Example 3 is a zoom lens having a zoom ratio of 9.51 and an F number of 3.43 to 6.50. Here, the closest distance is 500 mm at the wide-angle end and 800 mm at the telephoto end from the image plane.

  FIG. 10 is a lens cross-sectional view at the wide-angle end according to Embodiment 4 of the present invention. FIGS. 11A and 11B are aberration diagrams at the wide-angle end and the telephoto end when focusing on infinity according to the fourth embodiment. FIGS. 12A and 12B are aberration diagrams at the wide-angle end and the telephoto end when focusing on the closest distance according to the fourth embodiment. Example 4 is a zoom lens having a zoom ratio of 8.23 and an F number of 3.07 to 6.29. Here, the closest distance is 500 mm at the wide-angle end and 800 mm at the telephoto end from the image plane.

  FIG. 13 is a lens cross-sectional view at the wide-angle end according to Embodiment 5 of the present invention. 14A and 14B are aberration diagrams at the wide-angle end and the telephoto end when focusing on infinity according to the fifth embodiment. FIGS. 15A and 15B are aberration diagrams at the wide-angle end and the telephoto end when focusing on the closest distance according to the fifth embodiment. The fifth exemplary embodiment is a zoom lens having a zoom ratio of 4.07 and an F number of 2.78 to 6.71. Here, the closest distance is 500 mm at the wide-angle end and 800 mm at the telephoto end from the image plane. FIG. 16 is a schematic view of the main part of the imaging apparatus of the present invention.

  The zoom lens of each embodiment is an imaging optical system used in an imaging apparatus such as a video camera, a digital camera, or a silver salt film camera. In the lens cross-sectional view, the left side is the object side (front), and the right side is the image side (rear). The zoom lens of each embodiment may be used for a projector. In this case, the left side is the screen side and the right side is the projected image side. In the lens cross-sectional view, OL is a zoom lens. i indicates the order of the lens groups from the object side, and Li is the i-th lens group.

  Lr is a rear group composed of one or more lens groups. SP is an aperture stop for adjusting the amount of light. FC is a flare cut stop (FS stop) having a constant aperture diameter. Ln1 is a lens group having a negative refractive power, Ln2 is a lens group having a negative refractive power, Lp1 is a lens group having a positive refractive power, and Lp2 is a lens group having a positive refractive power. IP is an image plane. When used as an imaging optical system for a video camera or a digital still camera, the imaging surface of a solid-state imaging device (photoelectric conversion device) such as a CCD sensor or a CMOS sensor is used for a silver salt film camera. Corresponds to the film surface.

  In the lens cross-sectional view, solid arrows indicate the movement trajectory of each lens unit during zooming from the wide-angle end to the telephoto end when focused at infinity.

  Among the aberration diagrams, in the spherical aberration diagram, the solid line d is the d line, and the two-dot chain line g is the g line. In the astigmatism diagram, the dotted line M is the meridional image plane at the d line, and the solid line S is the sagittal image plane at the d line. Moreover, the figure which shows distortion has shown the distortion in d line | wire. The lateral chromatic aberration is shown for the g-line. Fno is the F number, and ω is the half angle of view. In the following embodiments, the wide-angle end and the telephoto end refer to zoom positions when the zoom lens unit is positioned at both ends of a range in which the mechanism can move on the optical axis.

  The first exemplary embodiment includes a lens unit L1 having a positive refractive power on the object side of the lens unit Ln1, and the rear unit LR includes a lens unit L5 having a positive refractive power disposed in order from the object side to the image side, and a weak negative lens unit L5. The lens unit L6 has a refractive power and the lens unit L7 has a negative refractive power. The lens unit L5 has the strongest refractive power among the lens units having a positive refractive power.

  The second exemplary embodiment includes a lens unit L1 having a positive refractive power on the object side of the lens unit Ln1, and the rear unit LR includes a lens unit L5 having a positive refractive power arranged in order from the object side to the image side, and a negative refraction. The lens unit L6 includes a lens unit L6 having a positive power and a lens unit L7 having a positive refractive power. The lens unit L5 has the strongest refractive power among the lens units having a positive refractive power.

  The third exemplary embodiment includes a lens unit L1 having a positive refractive power on the object side of the lens unit Ln1, and the rear unit LR includes a lens unit L5 having a positive refractive power disposed in order from the object side to the image side, and positive refraction. The lens unit L6 includes a power lens unit L6, a lens unit L7 having a negative refractive power, and a lens unit L8 having a weak negative refractive power. The lens unit L6 has the strongest refractive power among the lens units having a positive refractive power.

  The fourth exemplary embodiment includes a lens unit L1 having a positive refractive power on the object side of the lens unit Ln1, and the rear unit LR includes a lens unit L5 having a positive refractive power arranged in order from the object side to the image side, and positive refraction. The lens unit L6 includes a force lens group L6. The lens unit L6 has the strongest refractive power among the lens units having a positive refractive power.

  In Example 5, the rear lens group LR includes a lens unit L4 having a positive refractive power, a lens unit L5 having a positive refractive power, a lens unit L6 having a negative refractive power, and a positive refractive power arranged in order from the object side to the image side. Lens unit L7. The lens unit L5 has the strongest refractive power among the lens units having a positive refractive power.

  Next, features of the zoom lens according to each embodiment of the present invention will be described. First, a description will be given of factors that cause a change in image magnification (change in imaging magnification) during focusing in a zoom lens. A lens group that moves on the optical axis during focusing is hereinafter referred to as a focusing lens group. Let f (d), dist (d), and sk (d) be the focal length, distortion, and image plane position, respectively, as a function of the moving amount d of the focusing lens group during focusing.

The change in image magnification is the ratio between the differential amount f ′ (d) of the focal length and the differential amount sk ′ (d) of the image plane position with respect to each of the differential amount dist ′ (d) of distortion.
f ′ (d) / sk ′ (d)
dist '(d) / sk' (d)
Occurs when one of the two is large. Here, sk ′ (d) represents the focus sensitivity (ratio of the image plane movement amount per unit movement of the focusing lens group).

  Normally, when the lens is designed, the higher the focus sensitivity, the smaller the driving amount of the focusing lens group, which is advantageous for downsizing the entire system. However, if the focusing sensitivity is too high, it becomes difficult to perform high-precision focusing control. Therefore, in general, the upper limit of the focusing sensitivity is determined by the stopping accuracy of the actuator. Therefore, the magnitude of the image magnification change of the focusing lens group is determined by either the differential amount f ′ (d) or the differential amount dist ′ (d).

  Here, the differential amount dist '(d) can be easily reduced by a design matter such as disposing an aspheric surface at a position where the incident height ha of the off-axis principal ray is high. Therefore, the amount of change in image magnification is mainly determined by the differential amount f ′ (d) determined by the power arrangement (refractive power arrangement) of the optical system. Here, a zoom lens having a small image magnification change disclosed in Patent Document 1, a zoom lens having a relatively large image magnification change disclosed in Patent Document 2, and a variator focus having a large image magnification change disclosed in Patent Document 3 (focus by a zoom lens group). Take a zoom lens as an example. At this time, when the differential amount f ′ (d) is compared, the relationship is 1: 4: 5. That is, the above hypothesis is proved.

  Next, in these Patent Documents 1 to 3, a difference analysis on the refractive power arrangement in which a difference in the differential value f ′ (d) occurs is performed. As described above, these three Patent Documents 1 to 3 show that the refractive power of the focusing lens group is greatly different despite the fact that the focusing sensitivity does not change much. It has been found that the zoom lens of Patent Document 1 is the weakest, followed by Patent Document 2 and Patent Document 3, which are arranged in order of magnitude of image magnification change. When the lens group having a strong refractive power and the lens group having a low refractive power are moved by the same amount, the change in the focal length (differential amount) f ′ (d) is naturally a lens group having a strong refractive power. ,it is obvious.

  Then, when the refracting power of the focusing lens group is largely different, the same degree of focusing sensitivity sk ′ (d) is obtained, and when this is clarified, the mechanism by which the image magnification change occurs is elucidated. It will be. Attention was focused on the light collection states of the light beams before and after (object side and image side) of the focusing lens groups of the three patent documents 1 to 3. In Patent Document 1, the light beam incident in the focusing drive direction is largely converged on the focusing lens group. In Patent Document 2 and Patent Document 3, the light beam incident on the focusing lens group in the focusing drive direction is a loosely convergent light beam.

  When the light beam is converged toward the focusing drive direction, when the focusing lens group moves, the incident light h on the axis changes greatly in the direction of decreasing, so the imaging magnification of the lens group changes even with a weak refractive power. It becomes easy to obtain. When close to afocal in the driving direction, since the incident height h of the axial ray height does not change, it is necessary to change the imaging magnification of the lens group with a correspondingly strong refractive power. This is the reason why the focusing sensitivity sk ′ (d) can be made equal even though the refractive powers of the focusing lens groups are greatly different.

  From the above, it can be seen that in order to reduce the change in image magnification, it is important to dispose the focusing lens group in a strong convergent light beam in the driving direction. In order to arrange the focusing lens group in the strong converging light beam, there is a method of arranging the focusing lens group in the vicinity of the image side as in Patent Document 1, but this increases the size of the entire system as described above.

  In view of this, the inventor of the present invention has focused attention on a portion in the vicinity of the zooming lens unit on the object side where the incident height h of the on-axis light beam greatly changes due to strong negative refractive power. As an example, taking the wide-angle end of a four-unit zoom lens composed of first to fourth lens units having positive, negative, positive, and positive refractive powers in order from the object side, for example, from the third lens group to the object side. Heading to the second lens group, the light beam becomes a loose convergent light beam. By placing the lens unit Lp1 having a positive refractive power in the loose convergent light beam, a strong converged light beam is formed on the object side. It has been found that if a lens unit Ln2 having a negative refractive power is arranged on the object side, a focusing lens unit having a small refractive power and a small change in image magnification can be obtained.

  Further, the lens unit Ln1 having a strong negative refractive power is disposed on the object side, thereby giving the refractive power of the original lens unit for zooming. Here, the lens unit Ln2 and the lens unit Ln1 are made close to the limit after the focusing driving of the lens unit Ln2, thereby reducing the size of the entire system, and the lens unit Lp1 is also limited to the limit when focused on the infinity of the lens unit Ln2. Move closer. As a result, not only the entire system was downsized but also the convergent refractive power of the lens unit Lp1 could be obtained effectively.

  In this design, the first lens group to the fourth lens having the original positive, negative, positive, and positive refractive powers are obtained by combining the three lens groups of the lens group Ln1, the lens group Ln2, and the lens group Lp1. The refracting power is arranged as in the second lens group of the four-group zoom lens. In other words, the zoom lens according to the present invention has a shape in which focusing is performed with the middle lens group obtained by dividing the variable power lens group into three lens groups having negative, negative, and positive refractive powers. In such a case, normally, the decentration sensitivity of each lens in the lens group for zooming is very high, and if these are disassembled as separate lens groups, the manufacture becomes difficult.

  Therefore, in the present invention, the distance between the lens unit Ln1 and the lens unit Lp1 is fixed during zooming. That is, by moving both of them integrally (with the same trajectory) and taking a mechanism in which the lens unit Ln2 performs focusing driving, manufacturing of each lens unit is facilitated.

  Conventionally, it is known to divide a lens unit for zooming into two lens groups, a lens group having a negative refractive power and a lens group having a negative refractive power, and performing focusing with the lens group on the image side. (Patent Documents 4 and 5). In this focusing method, since there is no lens unit Lp1, the convergence of the light beam incident on the focusing lens unit is weak and the image magnification change is large. If the negative refractive power of the lens unit for zooming is divided approximately evenly, the negative refractive power of the focusing lens unit becomes very strong.

  For this reason, if the focusing lens group is arranged away from the image side by the amount corresponding to the focusing drive amount, the principal point as the lens group for zooming, which is a combination of the two lens units having negative refractive power, moves greatly to the image side. However, it was difficult to reduce the size and wide angle of the entire system. On the other hand, the present invention has a lens unit Lp1 having a positive refractive power, so that the principal point as a lens unit for zooming combining the three lens units can be arranged largely on the object side. It is easy to downsize and widen the angle of view.

  Next, the zoom lens of the variator focus that performs focusing with the second lens unit having a negative refractive power for zooming as in Patent Document 3 and the zoom lens of the present invention will be compared. In the zoom lens according to the present invention, the lens unit for zooming becomes thicker by the driving amount of the lens unit Ln2, but conversely, the distance between the first lens unit having positive refractive power and the lens unit Ln1 is not driven for focusing. It can be greatly narrowed. This facilitates downsizing and widening the angle of the entire system.

  As a result, it is easy to obtain a quiet-drive zoom lens that divides the normal zoom lens group into two, and is approximately the same size as a zoom lens that focuses with one lens group and has a small image magnification change. It becomes.

  For the above reasons, the best mode for carrying out the zoom lens of the present invention is that in order from the object side to the image side, the lens unit Ln1 having a negative refractive power, the lens unit Ln2 having a negative refractive power, and the positive refraction. The power lens group Lp1 has a rear group including one or more lens groups. It is preferable that the distance between the lens unit Ln1 and the lens unit Lp1 is constant during zooming, and the lens unit Ln2 is moved to the object side during focusing from infinity to short distance.

  Next, a more preferable configuration for implementing the present invention will be described. The rear group LR includes a lens unit Lp2 having a positive refractive power, and the lens group Lp2 has the shortest focal length among the positive refractive power lens units included in the zoom lens, and at the telephoto end compared to the wide-angle end. The distance between the lens unit Lp1 and the lens unit Lp2 is preferably narrow. As a result, the distance between the lens units Ln1 and Lp2 is reduced, so that zooming can be performed effectively.

  In each embodiment, it is preferable to satisfy one or more of the following conditional expressions. The imaging magnification of the lens unit Ln2 at the wide angle end is βLn2w, and the imaging magnification of the lens unit Ln2 at the telephoto end is βLn2t. Let βLp1w be the imaging magnification of the lens unit Lp1 at the wide-angle end. Let βLp1t be the imaging magnification of the lens unit Lp1 at the telephoto end.

  The focal length of the lens unit Ln2 is fLn2, and the focal length of the lens unit Lp1 is fLp1. Let the focal length of the lens unit Ln1 be fLn1. The focal length of the lens unit L1 is fL1, and the focal length of the entire system at the wide angle end is fw. Let the focal length of the lens unit Lp2 be fLp2. At this time, it is preferable to satisfy one or more of the following conditional expressions.

0.0 <βLn2w <1.0 (1)
0.0 <βLn2t <1.0 (2)
1.1 <βLp1w <5.0 (3)
1.1 <βLp1t <5.0 (4)
1.0 <−fLn2 / fLp1 <2.5 (5)
2.0 <fLn2 / fLn1 <20.0 (6)
2.0 <fL1 / fw <7.0 (7)
0.4 <−fLn1 / fw <1.5 (8)
2.0 <−fLn2 / fw <13.5 (9)
2.0 <fLp1 / fw <8.0 (10)
0.8 <fLp2 / fw <3.0 (11)

  Next, the technical meaning of the conditional expression described above and a preferable lens configuration of each lens group of the zoom lens will be described.

  Conditional expressions (1) and (2) are for effectively focusing with the lens unit Ln2. Deviating from the upper limit values of the conditional expressions (1) and (2) is not preferable because when the lens unit Ln2 moves from the image side to the object side, the lens group Ln2 is not in the convergent light beam, and the change in image magnification becomes large. When deviating from the lower limit values of the conditional expressions (1) and (2), it means that the lens unit Ln2 becomes divergent when moving from the image side toward the object side. Is too strong and it is difficult to drive with high accuracy, which is not preferable.

  Conditional expressions (3) and (4) are used to effectively converge the light beam from the lens unit Lp1 toward the object side by the positive refractive power of the lens unit Lp1, and reduce the change in image magnification due to the focusing of the lens unit Ln2. Is. When deviating from the upper limit values of the conditional expressions (3) and (4), the positive refractive power of the lens unit Lp1 is too strong, and the lens unit for zooming is obtained by combining the lens unit Ln1, the lens unit Ln2, and the lens unit Lp1. This is not preferable because the negative refractive power of is weakened.

  When deviating from the lower limit values of the conditional expressions (3) and (4), the positive refractive power of the lens unit Lp1 is too weak, the convergence of the light beam on the object side is weakened, and the image magnification change due to focusing at the lens unit Ln2 Since it becomes large, it is not preferable.

  Conditional expression (5) relates to the ratio between the refractive power of the lens unit Ln2 and the refractive power of the lens unit Lp1, and is intended to reduce the change in image magnification due to focusing while making the focusing sensitivity appropriate. Deviating from the upper limit value of conditional expression (5) is not preferable because the negative refractive power of the lens unit Ln2 is too weak, the sensitivity of focusing is reduced, the amount of focusing drive during focusing is increased, and the entire system is enlarged. . Deviating from the lower limit value of conditional expression (5) is not preferable because the positive refractive power of the lens unit Lp1 is too weak and the image magnification change becomes large.

  Conditional expression (6) relates to the ratio between the refractive power of the lens unit Ln1 and the refractive power of the lens unit Ln2, in order to make the entire system small and widen the angle of view, and to make the focusing sensitivity appropriate. It is. Deviating from the upper limit value of conditional expression (6) is not preferable because the negative refractive power of the lens unit Ln2 is too weak, the sensitivity of focusing is reduced, the amount of focusing drive during focusing is increased, and the entire system is enlarged. . When deviating from the lower limit value of conditional expression (6), the negative refractive power of the lens unit Ln2 is too strong, and the negative principal point position as the lens unit for zooming moves to the image side. It becomes difficult to achieve a wide angle of view while aiming.

  The zoom lens of the present invention is a positive lead type zoom lens in which the object side is a lens unit having a positive refractive power, even if it is a negative lead type zoom lens in which the object side is a lens unit having a negative refractive power. May be. With a negative lead type zoom lens, it is easy to widen the angle of view.

  On the other hand, in the positive lead type zoom lens, the luminous flux is converged by the first lens unit having a positive refractive power, and the diameter of the lens unit having a negative refractive power is reduced, thereby facilitating quiet driving focusing. A lens configuration having a lens unit L1 having a positive refractive power on the most object side and widening the distance between the lens unit L1 and the lens unit Ln1 during zooming from the wide-angle end to the telephoto end is preferable. Further, when the lens unit L1 moves to the object side during zooming from the wide-angle end to the telephoto end, the total lens length at the wide-angle end is shortened, and the entire system can be easily downsized.

  Conditional expression (7) sets a preferable focal length range of the lens unit L1 at this time. Conditional expression (7) is for making the focal length of the lens unit L1 appropriate, miniaturizing the entire system, and reducing variations in spherical aberration due to zooming. Deviating from the upper limit value of conditional expression (7) is not preferable because the positive refractive power of the lens unit L1 is too weak and the entire system becomes large. Deviating from the lower limit value of conditional expression (7) is not preferable because the positive refractive power of the lens unit L1 is too strong and the variation of spherical aberration accompanying zooming becomes large.

  Conditional expression (8) makes the negative refractive power of the lens unit Ln1 having the majority of the negative refractive power of the lens unit for zooming appropriate, and zooms while reducing the size of the entire system and widening the angle of view. This is to satisfactorily correct the accompanying spherical aberration and field curvature fluctuation. Deviating from the upper limit value of conditional expression (8) is not preferable because the negative refractive power of the lens unit Ln1 is too weak and the entire system becomes large. Deviating from the lower limit value of the conditional expression (8) is not preferable because the negative refractive power of the lens unit Ln1 is too strong, and the spherical aberration and the variation in field curvature accompanying zooming increase.

  Conditional expression (9) is for reducing the entire system size and increasing the angle of view while making the negative refractive power of the focusing lens group (lens group Ln2) appropriate and making the focusing sensitivity appropriate. Deviating from the upper limit value of conditional expression (9) is not preferable because the negative refractive power of the focusing lens group is too weak, the amount of focusing drive increases, and the entire system increases in size. If the lower limit of conditional expression (9) is deviated, the negative refractive power of the focusing lens group is too strong, making focusing control difficult, and the principal point of the lens group for zooming moves to the image side. It becomes difficult to reduce the size and wide angle of the system.

  Conditional expression (10) is for reducing the overall system size and widening the angle while making the positive refractive power of the lens unit Lp1 appropriate and reducing the change in image magnification in the lens unit Ln2. If the upper limit of conditional expression (10) is deviated, the positive refractive power of the lens unit Lp1 is too weak, the convergence of the light beam from the image side of the lens unit Ln2 toward the object side is weakened, and the change in image magnification becomes large. Therefore, it is not preferable. If the lower limit value of conditional expression (10) is deviated, the positive refractive power of the lens unit Lp1 is too strong, and the negative refractive power as the variable power lens unit becomes weak. It becomes difficult to achieve keratinization.

  Conditional expression (11) is for making the positive refractive power of the lens unit Lp2 appropriate, miniaturizing the entire system, and reducing the variation of spherical aberration due to zooming. Deviating from the upper limit value of conditional expression (11) is not preferable because the positive refractive power of the lens unit Lp2 is too weak and the entire system is enlarged. Deviating from the lower limit value of conditional expression (11) is not preferable because the positive refractive power of the lens unit Lp2 is too strong and the variation of spherical aberration accompanying zooming becomes large.

Preferably, the numerical ranges of conditional expressions (1) to (11) are as follows.
0.5 <βLn2w <0.9 (1a)
0.5 <βLn2t <0.9 (2a)
1.2 <βLp1w <2.0 (3a)
1.2 <βLp1t <2.0 (4a)
1.2 <−fLn2 / fLp1 <2.0 (5a)
4.0 <fLn2 / fLn1 <15.0 (6a)
3.5 <fL1 / fw <6.0 (7a)
0.50 <−fLn1 / fw <1.35 (8a)
3.0 <−fLn2 / fw <12.5 (9a)
2.5 <fLp1 / fw <7.0 (10a)
1.0 <fLp2 / fw <2.5 (11a)

  The lens group Ln1 may have two or more negative lenses. The lens group Ln1 has most of negative refractive power as a lens group for zooming. Therefore, it is preferable to have two or more negative lenses and disperse the negative refractive power. The lens group Ln2 may include one or more negative lenses and one or more positive lenses. Since the lens unit Ln2 is a lens unit having a negative refractive power, the lens unit Ln2 includes one or more negative lenses. Further, during the focusing drive, the variation in spherical aberration mainly at the telephoto end and the variation in image plane at the wide-angle end. In order to correct, it is preferable to have one or more positive lenses.

  In particular, in order to reduce the size and weight of the lens unit Ln2 that is a focusing lens unit, it is more preferable that the lens unit Ln2 includes two or less negative lenses and one positive lens. More preferably, the lens unit Ln2 is composed of one negative lens and one positive lens. A zooming method in which the distance between the lens unit Ln1 and the lens unit Ln2 is wider at the telephoto end than at the wide-angle end is preferable. Accordingly, by disposing the lens unit Ln2 on the object side at the wide-angle end, it becomes easy to widen the angle of view, and the distance between the lens unit Ln2 and the lens unit Lp1 is reduced toward the zoom position at the telephoto end, so that the zooming effect is achieved. Is sufficiently obtained.

  Hereinafter, the lens configuration in each embodiment will be described. The first exemplary embodiment includes the following lens groups arranged in order from the object side to the image side. The first lens unit L1 having a positive refractive power, the second lens unit L2 having a negative refractive power, the third lens unit L3 having a negative refractive power, the fourth lens unit L4 having a positive refractive power, and the first lens unit L4 having a positive refractive power. 5 lens group L5, 6th lens group L6 of negative refractive power, and 7th lens group L7 of weak negative refractive power. Example 1 is a seven-group zoom lens having a zoom ratio of 9.7.

  The second lens group L2 has a negative refractive power lens group Ln1, the third lens group L3 has a negative refractive power lens group Ln2, the fourth lens group L4 has a positive refractive power lens group Lp1, and a fifth lens group L5. Corresponds to the lens unit Lp2 having a positive refractive power. Focusing from infinity to short distance is performed by moving the third lens unit L3 to the object side. The third lens unit L3 is composed of one negative lens and one positive lens, and has a small and lightweight lens configuration, thereby facilitating quiet driving during focusing. The second lens unit L2 includes two negative lenses, and holds most of the negative refractive power as a variable power lens unit.

  The distance between the first lens group L1 and the second lens group L2 is larger at the telephoto end than at the wide-angle end, the distance between the second lens group L2 and the third lens group L3 is large, and the third lens group L3 and the fourth lens group. The interval of L4 is narrow. Further, the distance between the fourth lens group L4 and the fifth lens group L5 is narrow, the distance between the fifth lens group L5 and the sixth lens group L6 is wide, and the distance between the sixth lens group L6 and the seventh lens group L7 is narrowed. Zooming in. Further, the distance between the second lens group L2 and the fourth lens group L4 and the distance between the fifth lens group L5 and the seventh lens group L7 are constant during zooming, thereby reducing optical performance degradation due to manufacturing errors. ing.

  The relationship between the refractive powers of the second lens unit L2, the third lens unit L3, and the fourth lens unit L4 satisfies the conditional expressions (5), (6), (8), (9), and (10). As a result, high focusing sensitivity is obtained while weakening the refractive power of the focusing lens group, and as a result, changes in image magnification are reduced.

  Further, when the second lens unit L2 to the fourth lens unit L4 are regarded as a lens unit for zooming, the combined principal point position is moved to the object side as much as possible, thereby widening the angle of view and reducing the size of the entire system. We are trying to make it. Further, the image magnification of the third lens unit L3 satisfies the conditional expressions (1) and (2) at both the wide-angle end and the telephoto end, whereby the light beam in the third lens unit L3 is seen from the image side. Focusing with a small change in image magnification is facilitated by focusing light toward the object side.

  The image magnification in the fourth lens unit L4 satisfies the conditional expressions (3) and (4) at both the wide-angle end and the telephoto end, and is a strong convergent light beam toward the object side of the fourth lens unit L4. An appropriate focusing sensitivity is obtained while the negative refractive power of the three lens unit L3 is weakened. Further, the first lens unit L1 satisfies the conditional expression (7), thereby reducing the variation in spherical aberration during zooming while reducing the size of the entire system. Further, the fifth lens unit L5 satisfies the conditional expression (11), thereby reducing the variation in spherical aberration during zooming while reducing the size of the entire system.

  The second exemplary embodiment includes the following lens groups arranged in order from the object side to the image side. The first lens unit L1 having a positive refractive power, the second lens unit L2 having a negative refractive power, the third lens unit L3 having a negative refractive power, the fourth lens unit L4 having a positive refractive power, and the first lens unit L4 having a positive refractive power. The lens unit includes a fifth lens unit L5, a sixth lens unit L6 having a negative refractive power, and a seventh lens unit L7 having a positive refractive power. The second embodiment is a seven-group zoom lens having a zoom ratio of 9.7.

  The second lens group L2 has a negative refractive power lens group Ln1, the third lens group L3 has a negative refractive power lens group Ln2, the fourth lens group L4 has a positive refractive power lens group Lp1, and a fifth lens group L5. Corresponds to the lens unit Lp2 having a positive refractive power. Focusing from infinity to short distance is performed by moving the third lens unit L3 to the object side.

  The third lens unit L3 is composed of two negative lenses and one positive lens, and has a small and lightweight lens configuration, thereby facilitating quiet driving during focusing. The second lens unit L2 is composed of two negative lenses, and holds most of the negative refractive power as a variable power lens unit.

  The distance between the first lens group L1 and the second lens group L2 is larger at the telephoto end than at the wide-angle end, the distance between the second lens group L2 and the third lens group L3 is large, and the third lens group L3 and the fourth lens group. The interval of L4 is narrow. Further, the distance between the fourth lens group L4 and the fifth lens group L5 is narrow, the distance between the fifth lens group L5 and the sixth lens group L6 is wide, and the distance between the sixth lens group L6 and the seventh lens group L7 is narrowed. Zooming in. Further, the distance between the second lens group L2 and the fourth lens group L4 and the distance between the fifth lens group L5 and the seventh lens group L7 are constant during zooming, thereby reducing optical performance degradation due to manufacturing errors. ing.

  The optical action of each lens group regarding the conditional expressions (1) to (11) is the same as that of the first embodiment. The third exemplary embodiment includes the following lens groups arranged in order from the object side to the image side. The first lens unit L1 having a positive refractive power, the second lens unit L2 having a negative refractive power, the third lens unit L3 having a negative refractive power, the fourth lens unit L4 having a positive refractive power, and the first lens unit L4 having a positive refractive power. It consists of five lens units L5. Further, the lens unit includes a sixth lens unit L6 having a positive refractive power, a seventh lens unit L7 having a negative refractive power, and an eighth lens unit L8 having a weak negative refractive power. Example 3 is an 8-group zoom lens with a zoom ratio of 9.5.

  The second lens group L2 has a negative refractive power lens group Ln1, the third lens group L3 has a negative refractive power lens group Ln2, the fourth lens group L4 has a positive refractive power lens group Lp1, and a sixth lens group L6. Corresponds to the lens unit Lp2 having a positive refractive power. Focusing from infinity to short distance is performed by moving the third lens unit L3 to the object side. The third lens unit L3 has a lens configuration that is smaller and lighter than one negative lens and one positive lens, thereby facilitating quiet driving during focusing.

  The second lens unit L2 includes two negative lenses, and holds most of the negative refractive power as a variable power lens unit. The distance between the first lens unit L1 and the second lens unit L2 is larger at the telephoto end than at the wide-angle end, the interval between the second lens unit L2 and the third lens unit L3 is narrow, and the third lens unit L3 and the fourth lens unit L4. The interval of is narrow. Further, the distance between the fourth lens group L4 and the fifth lens group L5 is narrow, the distance between the fifth lens group L5 and the sixth lens group L6 changes slightly, and the distance between the sixth lens group L6 and the seventh lens group L7 is changed. Zooming is performed so that the distance between the seventh lens unit L7 and the eighth lens unit L8 is wide.

  Further, the distance between the second lens group L2 and the fourth lens group L4 and the distance between the sixth lens group L6 and the eighth lens group L8 are constant during zooming, thereby reducing optical performance degradation due to manufacturing errors. ing. Compared to the first embodiment, the fifth lens unit L5 and the sixth lens unit L6 are separated into two lens units having a positive refractive power to reduce fluctuations in coma during zooming.

  The optical action of each lens group regarding the conditional expressions (1) to (11) is the same as that of the first embodiment. The fourth exemplary embodiment includes the following lens groups arranged in order from the object side to the image side. The first lens unit L1 having a positive refractive power, the second lens unit L2 having a negative refractive power, the third lens unit L3 having a negative refractive power, the fourth lens unit L4 having a positive refractive power, and the first lens unit L4 having a positive refractive power. 5 lens group L5 and 6th lens group L6 of positive refractive power. Example 4 is a 6-group zoom lens with a zoom ratio of 8.2.

  The second lens group L2 has a negative refractive power lens group Ln1, the third lens group L3 has a negative refractive power lens group Ln2, the fourth lens group L4 has a positive refractive power lens group Lp1, and a sixth lens group L6. Corresponds to the lens unit Lp2 having a positive refractive power. Focusing from infinity to short distance is performed by moving the third lens unit L3 to the object side. The third lens unit L3 is composed of one negative lens and one positive lens, and has a small and lightweight lens configuration, thereby facilitating quiet driving during focusing. The second lens unit L2 includes two negative lenses, and holds most of the negative refractive power as a variable power lens unit.

  Compared to the wide-angle end, the distance between the first lens group L1 and the second lens group L2 is wider at the telephoto end, the distance between the second lens group L2 and the third lens group L3 is larger, and the third lens group L3 and the fourth lens group. The interval of L4 is narrow. Further, zooming is performed so that the distance between the fourth lens group L4 and the fifth lens group L5 is narrow and the distance between the fifth lens group L5 and the sixth lens group L6 is narrowed. Further, the distance between the second lens unit L2 and the fourth lens unit L4 is constant during zooming, thereby reducing optical performance degradation due to manufacturing errors.

  Compared to Example 1, the optical action of the sixth lens unit L6 corresponding to the lens unit Lp2 is the same. The optical action of each lens group regarding the conditional expressions (1) to (11) is the same as that of the first embodiment.

  Examples 1 to 4 are positive lead type zoom lenses, but the zoom lens of the present invention can be similarly applied to negative lead type zoom lenses. Example 5 is a negative lead type zoom lens. The fifth embodiment includes the following lens units arranged in order from the object side to the image side. First lens unit L1 having negative refractive power, second lens unit L2 having negative refractive power, third lens unit L3 having positive refractive power, fourth lens unit L4 having positive refractive power, first lens unit having positive refractive power 5 lens group L5, 6th lens group L6 of negative refractive power, and 7th lens group L7 of positive refractive power. The fifth embodiment is a seven-group zoom lens having a zoom ratio of 4.1.

  The first lens unit L1 is a lens unit Ln1 having a negative refractive power, the second lens unit L2 is a lens unit Ln2 having a negative refractive power, the third lens unit L3 is a lens unit Lp1 having a positive refractive power, and a fifth lens unit L5. Corresponds to the lens unit Lp2 having a positive refractive power. Focusing from infinity to short distance is performed by moving the second lens unit L2 to the object side. The second lens unit L2 is composed of one negative lens and one positive lens, and has a small and lightweight lens configuration, thereby facilitating quiet driving during focusing.

  The first lens unit L1 is composed of two negative lenses, and holds most of the negative refracting power as a variable power lens unit. Compared to the wide-angle end, the distance between the first lens unit L1 and the second lens unit L2 changes slightly at the telephoto end, and the interval between the second lens unit L2 and the third lens unit L3 changes slightly. The distance between the third lens group L3 and the fourth lens group L4 is narrow, the distance between the fourth lens group L4 and the fifth lens group L5 is narrow, the distance between the fifth lens group L5 and the sixth lens group L6 is wide, Zooming is performed so that the distance between the lens unit L6 and the seventh lens unit L7 is narrow.

  Further, the distance between the first lens unit L1 and the third lens unit L3 is constant during zooming, thereby reducing optical performance degradation due to manufacturing errors.

  The relationship between the refractive powers of the first lens unit L1, the second lens unit L2, and the third lens unit L3 satisfies the conditional expressions (5), (6), (8), (9), and (10). As a result, high focusing sensitivity is obtained while weakening the refractive power of the focusing lens group, and as a result, changes in image magnification are reduced.

  Further, when the first lens unit L1 to the third lens unit L3 are regarded as a lens unit for zooming, the combined principal point position is moved to the object side as much as possible, thereby widening the angle of view and reducing the size. ing. Further, the image magnification of the second lens unit L2 satisfies the conditional expressions (1) and (2) at both the wide-angle end and the telephoto position, so that the light flux in the second lens unit L2 is reflected from the image side to the object side. Convergent light is applied toward the side to facilitate focusing with a small change in image magnification.

  The image magnification in the third lens unit L3 satisfies the conditional expressions (3) and (4) at both the wide-angle end and the telephoto end, and a strong convergent light beam toward the object side of the third lens unit L3. Thus, an appropriate focusing sensitivity is obtained while weakening the negative refractive power of the second lens unit L2. The fifth lens unit L5 satisfies the conditional expression (11), thereby reducing the variation of spherical aberration during zooming while reducing the size of the entire system.

  The single-lens reflex camera (imaging device) of the present invention shown in FIG. 16 will be described. FIG. 16 illustrates an image pickup apparatus having the zoom lenses of Examples 1 to 5. Reference numeral 10 denotes an interchangeable lens barrel. The zoom lens 1 is held by a lens barrel 2 that is a holding member. Reference numeral 20 denotes a camera body, which includes a quick return mirror 3 that reflects the light beam from the zoom lens 1 upward, and a focusing screen 4 that is disposed in the image forming apparatus of the zoom lens 1. Further, it is constituted by a penta roof prism (image inverting means) 5 for converting an inverted image formed on the focusing screen 4 into an erect image, an eyepiece 6 for observing the erect image, and the like.

  Reference numeral 7 denotes a photosensitive surface, on which a solid-state imaging device (photoelectric conversion device) or a silver salt film that receives an image formed by a zoom lens such as a CCD sensor or a CMOS sensor is arranged. At the time of shooting, the quick return mirror 3 is retracted from the optical path, and an image is formed on the photosensitive surface 7 by the zoom lens 1. The benefits described in the first to fifth embodiments can be effectively enjoyed in the imaging apparatus disclosed in the present embodiment.

  The imaging apparatus of the present invention can be similarly applied to a mirrorless single-lens reflex camera without the quick return mirror 3.

  As mentioned above, although the Example of the preferable optical system of this invention was described, it cannot be overemphasized that this invention is not limited to these Examples, A various deformation | transformation and change are possible within the range of the summary.

  Numerical data 1 to 5 corresponding to Examples 1 to 5 are shown below. In each numerical data, i indicates the order of the surfaces from the object side. In the numerical data, ri is the radius of curvature of the i-th lens surface in order from the object side, di is the i-th lens thickness and air spacing in order from the object side, and ndi and νdi are the values of the i-th lens in order from the object side. The refractive index and Abbe number of the material. BF is a back focus. The aspherical shape is the X axis in the optical axis direction, the H axis in the direction perpendicular to the optical axis, the positive light traveling direction, and R is the paraxial radius of curvature, K, A2, A4, A6, A8, A10, A12. When the aspheric coefficient is used,

Shall be given in In each aspheric coefficient, “e−x” means “10 ^−x ”. In addition to the specifications such as focal length and F number, the half angle of view and image height of the entire system are the maximum image height that determines the half angle of view, and the total lens length is the distance from the first lens surface to the image surface. The back focus BF indicates the length from the final lens surface to the image plane. Each lens group data indicates the lens groups and their focal lengths.

  Further, the portion where the interval d between the optical surfaces is (variable) changes during zooming, and the surface interval corresponding to the focal length is shown in the separate table. Table 1 shows the calculation results of the conditional expressions based on the lens data of numerical data 1 to 5 described below.

(Numeric data 1)
Unit mm

Surface data surface number rd nd νd Effective diameter
1 132.480 2.00 1.80440 39.6 63.34
2 58.479 9.30 1.49700 81.5 57.03
3 1004.808 0.15 55.31
4 61.378 7.05 1.59522 67.7 53.24
5 441.235 (variable) 52.42
6 * 1396.081 1.70 1.85400 40.4 35.67
7 * 21.758 6.08 27.46
8 -101.824 1.40 1.76385 48.5 27.36
9 55.563 (variable) 25.69
10 136.150 2.50 1.71736 29.5 22.82
11 -101.412 1.87 22.39
12 -26.398 1.20 1.49700 81.5 22.39
13 1518.313 (variable) 23.87
14 397.664 2.48 1.85478 24.8 24.93
15 -90.949 (variable) 25.37
16 ∞ 0.70 (variable)
17 (Aperture) ∞ (Variable) 26.58
18 27.817 5.94 1.49700 81.5 28.74
19 512.488 0.15 28.49
20 27.440 1.40 1.90366 31.3 27.93
21 16.263 8.74 1.58313 59.4 25.59
22 * -116.763 (variable) 24.95
23 -180.283 3.03 1.75520 27.5 20.87
24 -28.086 1.00 1.77250 49.6 20.56
25 * 42.446 0.30 19.68
26 21.981 2.00 1.72047 34.7 19.63
27 27.444 (variable) 19.03
28 25.585 3.92 1.51633 64.1 20.86
29 -1334.955 0.15 20.50
30 79.292 1.10 2.00100 29.1 20.21
31 15.227 4.87 1.49700 81.5 19.07
32 117.425 1.05 19.32
33 89.705 7.23 1.59270 35.3 19.85
34 -13.680 1.20 1.88300 40.8 20.26
35 -58.439 22.38

Aspheric data 6th surface
K = 0.00000e + 000 A 4 = 1.32120e-005 A 6 = -3.35744e-008 A 8 = 4.30207e-011 A10 = -7.07141e-015 A12 = -2.74350e-017

7th page
K = 0.00000e + 000 A 4 = 8.33223e-006 A 6 = -5.68507e-009 A 8 = -1.87147e-011 A10 = -1.56985e-013

22nd page
K = 0.00000e + 000 A 4 = 1.21704e-005 A 6 = -1.15174e-008 A 8 = -2.34645e-012 A10 = 8.04596e-014

25th page
K = 0.00000e + 000 A 4 = -4.43903e-006 A 6 = -1.20001e-009 A 8 = 1.07822e-010 A10 = -7.14391e-013

Various data Zoom ratio 9.67

Wide angle Medium telephoto focal length 24.30 99.99 234.98
F number 4.10 6.04 6.40
Half angle of view (degrees) 41.68 12.21 5.26
Image height 21.64 21.64 21.64
Total lens length 176.56 220.28 254.60
BF 38.70 85.02 92.03

d 5 0.90 31.00 63.15
d 9 8.14 4.85 9.80
d13 2.45 5.74 0.80
d15 19.93 1.50 1.50
d17 19.40 5.14 0.30
d22 1.15 6.53 7.65
d27 7.35 1.97 0.85

ea16 16.47 23.83 26.26

Zoom lens group data group Start surface Focal length Lens configuration length Front principal point position Rear principal point position
1 1 115.35 18.50 5.50 -6.46
2 6 -15.30 9.18 3.08 -4.17
3 10 -159.24 5.57 8.50 4.13
4 14 86.80 2.48 1.09 -0.25
5 16 ∞ 0.70 0.35 -0.35
6 18 29.82 16.23 2.63 -8.15
7 23 -61.56 6.34 3.39 -0.31
8 28 -720.48 19.52 81.88 61.39

(Numeric data 2)

Unit mm

Surface data surface number rd nd νd Effective diameter
1 115.094 2.00 1.90043 37.4 62.38
2 61.116 8.71 1.49700 81.5 56.97
3 597.125 0.15 56.14
4 64.719 7.23 1.59522 67.7 54.99
5 521.702 (variable) 54.22
6 * 217.632 1.60 1.85400 40.4 33.72
7 * 19.788 6.05 25.73
8 -77.964 1.30 1.76385 48.5 25.50
9 76.533 (variable) 23.98
10 96.863 1.15 1.77250 49.6 23.07
11 30.116 3.82 1.71736 29.5 22.00
12 -131.948 2.35 21.46
13 -22.042 1.10 1.59522 67.7 21.46
14 -199.817 (variable) 21.82
15 1534.963 3.07 1.62588 35.7 23.22
16 -41.748 (variable) 23.78
17 ∞ 0.50 (variable)
18 (Aperture) ∞ (Variable) 25.25
19 26.038 5.95 1.49700 81.5 27.44
20 786.155 0.15 27.16
21 25.948 1.40 1.90366 31.3 26.58
22 14.855 8.69 1.58313 59.4 24.13
23 * -105.696 (variable) 23.54
24 -101.691 5.23 1.75520 27.5 19.60
25 -19.948 1.00 1.77250 49.6 19.07
26 * 32.084 0.30 18.44
27 29.087 2.13 1.59551 39.2 18.71
28 65.081 (variable) 18.78
29 44.517 4.00 1.48749 70.2 21.26
30 -62.721 0.15 21.36
31 165.666 1.20 2.00 100 29.1 21.25
32 15.824 4.22 1.49700 81.5 20.74
33 36.751 0.15 21.76
34 26.293 6.51 1.59270 35.3 23.48
35 -41.718 1.86 23.95
36 -21.634 1.30 1.88300 40.8 23.95
37 -34.045 25.43

Aspheric data 6th surface
K = 0.00000e + 000 A 4 = 7.65377e-006 A 6 = -1.47714e-008 A 8 = 4.72399e-011 A10 = -7.13337e-014 A12 = 2.79748e-017

7th page
K = 0.00000e + 000 A 4 = 1.42514e-006 A 6 = -2.40422e-009 A 8 = 1.96364e-011 A10 = 2.69656e-013

23rd page
K = 0.00000e + 000 A 4 = 1.55967e-005 A 6 = -1.39770e-008 A 8 = -1.10046e-011 A10 = 1.40040e-013

26th page
K = 0.00000e + 000 A 4 = -1.00848e-005 A 6 = -3.62496e-009 A 8 = 1.87692e-010 A10 = -1.41895e-012

Various data Zoom ratio 9.67

Wide angle Medium telephoto focal length 24.30
F number 4.10 6.00 6.40
Half angle of view (degrees) 41.68 12.21 5.26
Image height 21.64 21.64 21.64
Total lens length 178.58 222.44 258.53
BF 38.70 85.15 91.52

d 5 0.90 31.69 65.43
d 9 1.86 2.92 6.00
d14 4.94 3.88 0.80
d16 18.91 1.50 1.50
d18 20.50 4.54 0.50
d23 1.32 7.69 8.71
d28 8.19 1.81 0.80

ea17 15.94 23.26 25.02

Zoom lens group data group Start surface Focal length Lens configuration length Front principal point position Rear principal point position
1 1 118.54 18.08 4.66 -6.97
2 6 -15.66 8.95 2.92 -4.24
3 10 -87.68 8.42 9.47 3.16
4 15 64.99 3.07 1.84 -0.05
5 17 ∞ 0.50 0.25 -0.25
6 19 28.22 16.19 2.65 -8.15
7 24 -46.64 8.66 2.63 -2.45
8 29 334.19 19.39 -5.13 -18.11

(Numerical data 3)

Unit mm

Surface data surface number rd nd νd Effective diameter
1 130.994 2.00 1.80440 39.6 62.69
2 58.583 9.29 1.49700 81.5 56.56
3 953.601 0.15 55.15
4 61.661 7.17 1.59522 67.7 53.83
5 437.699 (variable) 53.09
6 * 654.455 1.70 1.85400 40.4 35.33
7 * 20.900 6.57 27.16
8 -72.705 1.40 1.76385 48.5 26.95
9 78.864 (variable) 25.61
10 128.499 2.50 1.71736 29.5 22.67
11 -104.228 2.44 22.40
12 -26.403 1.20 1.49700 81.5 22.08
13 1291.374 (variable) 23.74
14 1112.240 2.44 1.85478 24.8 24.38
15 -79.983 (variable) 24.92
16 (Aperture) ∞ 0.00 26.05
17 27.286 5.75 1.49700 81.5 27.79
18 380.075 (variable) 27.55
19 28.137 1.40 1.90366 31.3 27.07
20 16.420 8.27 1.58313 59.4 24.97
21 * -130.611 (variable) 24.39
22 -240.099 3.25 1.75520 27.5 21.88
23 -29.981 1.00 1.77250 49.6 21.52
24 * 46.180 0.30 20.77
25 22.564 1.98 1.72047 34.7 20.91
26 27.164 (variable) 20.39
27 25.390 3.98 1.51633 64.1 20.39
28 -1025.644 0.15 20.03
29 66.284 1.10 2.00100 29.1 19.75
30 15.290 4.82 1.49700 81.5 18.84
31 107.452 1.33 19.24
32 153.111 6.91 1.59270 35.3 19.72
33 -13.749 1.20 1.88300 40.8 20.15
34 -57.017 22.24

Aspheric data 6th surface
K = 0.00000e + 000 A 4 = 1.10198e-005 A 6 = -3.08107e-008 A 8 = 5.85186e-011 A10 = -6.18886e-014 A12 = 2.71131e-017

7th page
K = 0.00000e + 000 A 4 = 5.85298e-006 A 6 = -1.50401e-008 A 8 = 2.22480e-011 A10 = -1.68569e-013

21st page
K = 0.00000e + 000 A 4 = 1.21224e-005 A 6 = -1.16227e-008 A 8 = 1.69214e-011 A10 = 4.07401e-014

24th page
K = 0.00000e + 000 A 4 = -3.94829e-006 A 6 = 8.62162e-009 A 8 = -9.21008e-012 A10 = -1.88190e-013

Various data Zoom ratio 9.51

Wide angle Medium Telephoto focal length 24.60 100.02 234.00
F number 3.43 6.09 6.50
Half angle of view (degrees) 41.33 12.21 5.28
Image height 21.64 21.64 21.64
Total lens length 176.41 220.91 254.55
BF 39.21 85.58 92.15

d 5 0.90 30.94 62.94
d 9 9.70 5.08 9.61
d13 0.71 5.33 0.80
d15 38.37 6.43 1.50
d18 0.51 0.54 0.54
d21 1.14 6.61 7.85
d26 7.56 2.09 0.85

Zoom lens group data group Start surface Focal length Lens configuration length Front principal point position Rear principal point position
1 1 115.42 18.62 5.41 -6.62
2 6 -15.31 9.67 3.10 -4.60
3 10 -164.94 6.14 10.67 5.58
4 14 87.38 2.44 1.23 -0.09
5 16 58.83 5.75 -0.30 -4.11
6 19 58.44 9.67 0.74 -5.37
7 22 -67.83 6.53 3.79 -0.03
8 27 -1038.25 19.49 128.69 102.34

(Numeric data 4)

Unit mm

Surface data surface number rd nd νd Effective diameter
1 119.585 2.00 1.80440 39.6 64.04
2 59.612 9.33 1.49700 81.5 60.09
3 368.173 0.15 59.26
4 65.779 7.53 1.59522 67.7 57.57
5 445.134 (variable) 56.76
6 * -515.488 1.70 1.85400 40.4 36.47
7 * 21.242 6.61 27.95
8 -95.887 1.40 1.76385 48.5 27.76
9 102.290 (variable) 26.64
10 3605.550 2.30 1.71736 29.5 22.94
11 -73.518 1.66 22.62
12 -26.667 1.20 1.49700 81.5 22.60
13 -210.343 (variable) 23.48
14 373.971 2.36 1.85478 24.8 24.26
15 -99.724 (variable) 24.65
16 (Aperture) ∞ 0.00 25.70
17 27.248 5.15 1.49700 81.5 27.21
18 141.864 0.96 26.89
19 25.043 1.40 1.90366 31.3 26.57
20 16.717 5.61 1.58313 59.4 24.75
21 * 40.974 2.49 24.04
22 142.102 3.19 1.75520 27.5 23.99
23 -47.894 1.00 1.77250 49.6 23.87
24 50.376 (variable) 23.50
25 21.934 5.62 1.51633 64.1 25.34
26 370.801 1.08 25.11
27 27.815 1.10 2.00 100 29.1 24.54
28 15.556 8.30 1.49700 81.5 22.77
29 -48.010 0.30 22.58
30 -204.624 6.23 1.59270 35.3 22.05
31 -15.654 1.20 1.88300 40.8 21.60
32 * 131.206 22.39

Aspheric data 6th surface
K = 0.00000e + 000 A 4 = 1.33977e-005 A 6 = -2.89383e-008 A 8 = 3.26785e-011 A10 = -8.83774e-016 A12 = -2.03321e-017

7th page
K = 0.00000e + 000 A 4 = 5.24173e-006 A 6 = 1.15011e-008 A 8 = -1.06391e-010 A10 = 8.71487e-014

21st page
K = 0.00000e + 000 A 4 = 1.10326e-005 A 6 = 8.71569e-009 A 8 = 2.12418e-012 A10 = 7.75948e-014

32nd page
K = 0.00000e + 000 A 4 = 1.09800e-005 A 6 = -2.03435e-008 A 8 = 5.05459e-010 A10 = -3.79728e-012 A12 = 1.13692e-014

Various data Zoom ratio 8.23

Wide angle Medium Telephoto focal length 24.30 100.00 200.00
F number 3.07 5.62 6.29
Half angle of view (degrees) 41.68 12.21 6.17
Image height 21.64 21.64 21.64
Total lens length 171.86 221.11 254.57
BF 38.70 85.00 96.09

d 5 0.90 38.66 65.60
d 9 10.06 6.42 10.54
d13 1.29 4.92 0.80
d15 31.64 4.90 1.50
d24 9.39 1.33 0.15


Zoom lens group data group Start surface Focal length Lens configuration length Front principal point position Rear principal point position
1 1 126.32 19.01 4.60 -7.68
2 6 -16.14 9.71 2.64 -5.16
3 10 -165.82 5.16 5.55 1.68
4 14 92.32 2.36 1.01 -0.27
5 16 73.84 19.81 -16.36 -24.43
6 25 57.98 23.83 -17.36 -25.25

(Numerical data 5)

Unit mm

Surface data surface number rd nd νd Effective diameter
1 * 101.865 2.70 1.58313 59.4 51.34
2 * 23.965 10.15 39.20
3 220.475 2.10 1.88300 40.8 39.02
4 60.772 (variable) 36.83
5 99.973 3.05 1.65412 39.7 31.09
6 -5281.346 2.41 30.37
7 -53.787 1.20 1.49700 81.5 30.18
8 458.967 (variable) 29.58
9 183.253 2.45 1.84666 23.8 29.40
10 -645.519 (variable) 29.33
11 (Aperture) ∞ 0.00 28.71
12 30.678 6.25 1.49700 81.5 31.65
13 358.328 (variable) 31.37
14 25.999 1.40 1.90366 31.3 30.60
15 18.568 9.18 1.58313 59.4 28.40
16 * -184.039 (variable) 27.38
17 -69.478 1.84 1.76182 26.5 25.24
18 -50.604 1.00 1.74320 49.3 24.85
19 * 30.342 (variable) 23.67
20 34.843 4.90 1.49700 81.5 24.18
21 -80.065 0.15 24.34
22 88.620 4.87 1.49700 81.5 24.31
23 -37.070 0.17 24.22
24 -424.133 5.24 1.59270 35.3 23.55
25 -22.500 1.20 1.88300 40.8 23.15
26 * 66.265 23.35

Aspheric data 1st surface
K = 0.00000e + 000 A 4 = 1.26758e-005 A 6 = -2.97938e-008 A 8 = 4.61726e-011 A10 = -3.93749e-014 A12 = 1.45888e-017

Second side
K = 0.00000e + 000 A 4 = 1.11654e-005 A 6 = -2.01556e-008 A 8 = 2.75615e-013 A10 = 1.56083e-014

16th page
K = 0.00000e + 000 A 4 = 5.98081e-006 A 6 = -2.30949e-008 A 8 = 7.95036e-011 A10 = -1.14679e-013

19th page
K = 0.00000e + 000 A 4 = 1.68295e-006 A 6 = 3.98461e-008 A 8 = -1.10067e-010 A10 = 1.75347e-013

26th page
K = 0.00000e + 000 A 4 = 1.02711e-005 A 6 = -3.47587e-009 A 8 = 2.64713e-011 A10 = -1.18691e-013

Various data Zoom ratio 4.07

Wide angle Medium Tele focal length 24.60 50.00 100.00
F number 2.78 4.03 6.71
Half angle of view (degrees) 41.33 23.40 12.21
Image height 21.64 21.64 21.64
Total lens length 176.57 166.06 198.50
BF 39.19 66.32 117.51

d 4 14.42 13.10 14.42
d 8 0.80 2.12 0.80
d10 50.72 15.86 1.50
d13 3.23 1.52 0.50
d16 1.95 2.69 3.35
d19 6.01 4.20 0.16

Zoom lens group data group Start surface Focal length Lens configuration length Front principal point position Rear principal point position
1 1 -32.28 14.95 6.03 -6.20
2 5 -296.82 6.66 13.25 7.81
3 9 168.81 2.45 0.29 -1.04
4 11 67.08 6.25 -0.39 -4.54
5 14 48.32 10.58 0.40 -6.26
6 17 -28.16 2.84 1.10 -0.49
7 20 59.97 16.52 -8.53 -16.43

Ln1, Ln2, Lp1, Lp2 Lens group L1 First lens group L2 Second lens group L3 Third lens group L4 Fourth lens group L5 Fifth lens group L6 Sixth lens group L7 Seventh lens group L8 Eighth lens group

Claims (23)

After including a lens unit Ln1 having a negative refractive power, a lens unit Ln2 having a negative refractive power, a lens unit Lp1 having a positive refractive power, and one or more lens units, which are sequentially arranged from the object side to the image side. A zoom lens that includes a group and changes the interval between adjacent lens groups during zooming,
The zoom lens, wherein the lens unit Ln1 and the lens unit Lp1 move along the same locus during zooming, and the lens unit Ln2 moves toward the object side during focusing from infinity to a short distance.   The rear group includes a lens group Lp2 having a positive refractive power, and the lens group Lp2 is a lens group having the shortest focal length among the lens groups having a positive refractive power included in the zoom lens. 2. The zoom lens according to claim 1, wherein the distance between the lens unit Lp <b> 1 and the lens unit Lp <b> 2 is narrower at the telephoto end than in the zoom lens. When the focal length of the lens unit Lp2 is fLp2, and the focal length of the entire system at the wide angle end is fw,
0.8 <fLp2 / fw <3.0
The zoom lens according to claim 2, wherein the following conditional expression is satisfied. When the focal length of the lens unit Ln1 is fLn1, and the focal length of the entire system at the wide angle end is fw,
0.4 <-fLn1 / fw <1.5
The zoom lens according to claim 1, wherein the following conditional expression is satisfied. When the focal length of the lens unit Ln2 is fLn2, and the focal length of the entire system at the wide angle end is fw,
2.0 <−fLn2 / fw <13.5
The zoom lens according to claim 1, wherein the following conditional expression is satisfied. When the focal length of the lens unit Lp1 is fLp1, and the focal length of the entire system at the wide angle end is fw,
2.0 <fLp1 / fw <8.0
The zoom lens according to claim 1, wherein the following conditional expression is satisfied. When the imaging magnification of the lens group Ln2 at the wide angle end is βLn2w and the imaging magnification of the lens group Ln2 at the telephoto end is βLn2t,
0.0 <βLn2w <1.0
0.0 <βLn2t <1.0
The zoom lens according to claim 1, wherein the following conditional expression is satisfied. When the imaging magnification of the lens group Lp1 at the wide angle end is βLp1w,
1.1 <βLp1w <5.0
The zoom lens according to claim 1, wherein the following conditional expression is satisfied. When the imaging magnification of the lens group Lp1 at the telephoto end is βLp1t,
1.1 <βLp1t <5.0
The zoom lens according to claim 1, wherein the following conditional expression is satisfied. When the focal length of the lens group Ln2 is fLn2, and the focal length of the lens group Lp1 is fLp1,
1.0 <-fLn2 / fLp1 <2.5
The zoom lens according to claim 1, wherein the following conditional expression is satisfied. When the focal length of the lens group Ln1 is fLn1, and the focal length of the lens group Ln2 is fLn2.
2.0 <fLn2 / fLn1 <20.0
The zoom lens according to claim 1, wherein the following conditional expression is satisfied.   The zoom lens according to any one of claims 1 to 11, wherein the lens group Ln1 includes two or more negative lenses.   The zoom lens according to claim 1, wherein the lens group Ln2 includes a negative lens and a positive lens.   14. The zoom lens according to claim 1, wherein the distance between the lens unit Ln <b> 1 and the lens unit Ln <b> 2 is wider at the telephoto end than at the wide-angle end.   2. A lens unit L1 having a positive refractive power on the object side of the lens unit Ln1, and the distance between the lens unit L1 and the lens unit Ln1 is wider at the telephoto end than at the wide-angle end. The zoom lens according to any one of 1 to 14.   16. The zoom lens according to claim 15, wherein the lens unit L1 moves toward the object side during zooming from the wide-angle end to the telephoto end. When the focal length of the lens unit L1 is fL1, and the focal length of the entire system at the wide angle end is fw,
2.0 <fL1 / fw <7.0
The zoom lens according to claim 15, wherein the following conditional expression is satisfied. The rear group includes a lens unit L5 having a positive refractive power, a lens unit L6 having a negative refractive power, and a lens group L7 having a negative refractive power, which are arranged in order from the object side to the image side.
18. The zoom according to claim 1, wherein the lens unit L <b> 5 is a lens unit having a shortest focal length among lens units having a positive refractive power included in the zoom lens. lens. The rear group includes a lens unit L5 having a positive refractive power, a lens unit L6 having a negative refractive power, and a lens group L7 having a positive refractive power, which are arranged in order from the object side to the image side.
18. The zoom according to claim 1, wherein the lens unit L <b> 5 is a lens unit having a shortest focal length among lens units having a positive refractive power included in the zoom lens. lens. The rear group includes a lens unit L5 having a positive refractive power, a lens unit L6 having a positive refractive power, a lens unit L7 having a negative refractive power, and a lens unit having a negative refractive power, which are arranged in order from the object side to the image side. L8,
18. The zoom according to claim 1, wherein the lens unit L <b> 6 is a lens unit having a shortest focal length among lens units having a positive refractive power included in the zoom lens. lens. The rear group includes a lens unit L5 having a positive refractive power and a lens unit L6 having a positive refractive power, which are arranged in order from the object side to the image side.
18. The zoom according to claim 1, wherein the lens unit L <b> 6 is a lens unit having a shortest focal length among lens units having a positive refractive power included in the zoom lens. lens. The rear group includes a lens unit L4 having a positive refractive power, a lens unit L5 having a positive refractive power, a lens unit L6 having a negative refractive power, and a lens unit L7 having a positive refractive power disposed in order from the object side to the image side. Consists of
18. The zoom according to claim 1, wherein the lens unit L <b> 5 is a lens unit having a shortest focal length among lens units having a positive refractive power included in the zoom lens. lens.   23. An image pickup apparatus comprising: the zoom lens according to claim 1; and an image pickup element that receives an image formed by the zoom lens.