JP2012083601A - Zoom lens or imaging apparatus provided with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a zoom lens that is compact and suitable for moving image shooting, and an imaging apparatus.SOLUTION: A zoom lens comprises:, in order from an object side to an image side, a first lens group G1 having positive refractive power; a second lens group G2 having negative refractive power; an aperture diaphragm S; a third lens group G3 having positive refractive power; a fourth lens group G4 having negative refractive power; and a fifth lens group G5 having positive refractive power. When varying power from a wide angle end to a telephoto end, positions of the first lens group and the aperture diaphragm S are at least fixed, the second lens group G2 and the third lens group G3 are moved in an optical axis direction, and each distance between each lens group and the aperture diaphragm S is varied. When focusing from an infinity focusing state to a close range focusing state, the fourth lens group G4 is moved in an optical axis direction. The zoom lens satisfies the following conditional expression(1): -0.36<f4/f1<-0.05...(1) (where f1 represents a focal length of the first lens group, and f4 represents a focal length of the fourth lens group).

Description

  The present invention relates to a zoom lens having a constant overall length during zooming and focusing. In particular, the present invention relates to a compact, wide-angle, high-magnification zoom lens that is suitable for an interchangeable lens system and enables moving image shooting. Furthermore, the present invention relates to an image pickup apparatus including a zoom lens having a constant overall length during zooming and focusing.

  2. Description of the Related Art Conventionally, products that can shoot moving images are known for digital cameras. In recent years, an interchangeable lens corresponding to a moving image shooting function of a camera body has been studied even in an interchangeable lens digital camera.

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

  However, in video shooting, some professional video cameras are focused by a skilled cameraman with manual focus (MF). However, many consumer video cameras always use an AF system according to the subject distance. It is necessary to keep in focus. As a method for this, a contrast AF method (so-called hill-climbing method) using an image sensor is employed.

  Furthermore, in order to maintain the in-focus state, the change in contrast is measured by constantly moving the focus lens back and forth in the optical axis direction of the in-focus position (referred to as wobbling). If it is determined that the focus lens has been moved, the focus lens is appropriately moved to operate the focus again. Since this wobbling function requires a very high-speed operation in accordance with the frame rate, the lens used for wobbling is required to be lightweight.

  The focus lens is always moved, but the moving range is within the depth of focus. Therefore, it is controlled so that the blurring during wobbling cannot be recognized. At this time, if the change in the image magnification (change in the size of the subject on the imaging surface) is large, the image always appears to fluctuate, which is very unnatural. Accordingly, it is an important requirement to keep the magnification change during wobbling small.

  Among products capable of moving image shooting, products having a recording function are also known. When zooming is performed, recording is hindered if the sound generated from the interchangeable lens itself is loud. Therefore, in a zoom lens that supports the moving image shooting function, it is required to reduce the number of groups (lens group and aperture stop) that move during the zooming operation in order to sufficiently reduce the sound generated during the zooming operation. .

  In addition, an interchangeable lens used for both still image shooting and moving image shooting is required to have a wide angle and a high zoom ratio as the shooting application expands.

  Conventionally, positive, negative, positive, negative, and positive five-group zoom lenses are known as zoom lenses suitable for wide-angle and high zoom ratios.

  Patent Documents 1 to 6 propose design examples of a zoom lens of a positive, negative, positive, negative, and positive group suitable for wide angle and high zoom ratio. In Patent Document 1, the first to fifth lens groups are moved during zooming from the wide-angle end to the telephoto end.

  In Patent Documents 2 to 6, the first lens unit and the fifth lens unit are fixed at the time of zooming from the wide-angle end to the telephoto end. In Patent Documents 2, 3, 4, and 6, the aperture stop is also fixed. Further, in Patent Documents 2, 3, 5, and 6, the focusing is performed by moving the fourth lens group and the like, and is suitable for downsizing.

JP 2010-32702 A JP-A-8-5913 JP 2002-228931 A JP 2006-276808 A Japanese Patent Laid-Open No. 2007-3598 JP 2009-128620 A

  However, since the zoom lens disclosed in Patent Document 1 moves all the lens groups during the zooming operation, it is not a desirable configuration in terms of reducing the sound generated from the interchangeable lens itself. In particular, since the first lens group having the largest lens diameter is moved, noise during moving image shooting is easily noticeable.

  The zoom lenses disclosed in Patent Documents 2 to 6 have a desirable configuration in that the sound generated from the interchangeable lens itself is reduced because the first lens group is fixed during zooming operation.

  However, the zoom lenses disclosed in Patent Documents 2 and 3 are assumed to have a small image sensor such as a home video camera. Therefore, if these zoom lenses are multiplied by a factor and applied to a large-size image pickup device of about 4/3 inch as in each embodiment of the present invention, the size of the zoom lens becomes undesirably large.

  The zoom lens disclosed in Patent Document 4 has a zoom ratio as small as about 2.8, and there is no description of a focus lens group.

  The zoom lens disclosed in Patent Document 5 also has a small zoom ratio of about 2.8, and the aperture stop moves during zooming.

  Further, the zoom lens disclosed in Patent Document 6 is not sufficient in terms of miniaturization.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a zoom lens in which an image during focusing during moving image shooting and an image during a wobbling operation are easy to see. It is another object of the present invention to provide a zoom lens suitable for noise reduction during zooming during moving image shooting. It is another object of the present invention to provide a small wide-angle and high-magnification interchangeable lens that is used for both still image shooting and moving image shooting. Furthermore, it aims at providing the imaging device provided with such a zoom lens.

  In order to solve the above problems, a zoom lens according to the present invention is as follows.

The first zoom lens according to the present invention is a zoom lens disposed on the imaging surface side of the image sensor, and in order from the object side to the image side, the first lens group having a positive refractive power and the first lens unit having a negative refractive power. A second lens group, an aperture stop, a third lens group with positive refractive power, a fourth lens group with negative refractive power, and a fifth lens group with positive refractive power, from the wide-angle end to the telephoto end. At the time of zooming, at least the positions of the first lens group and the aperture stop are fixed, the second lens group and the third lens group move in the direction of the optical axis, and between the lens groups and the aperture stop. Each interval changes, and the fourth lens unit moves in the optical axis direction during focusing from the infinitely focused state to the close-in-focus state and satisfies the following conditional expression (1). And
−0.36 <f4 / f1 <−0.05 (1)
However,
f1 is the focal length of the first lens group,
f4 is a focal length of the fourth lens group,
It is.

  Hereinafter, the reason and operation of the zoom lens according to the present invention will be described.

  Employing a positive leading type zoom lens in which a lens unit having a positive refractive power is disposed closest to the object side is advantageous in securing a zoom ratio, and is a preferable lens arrangement as a wide-angle / high zoom lens. The main variable magnification is caused by the change in the distance between the first lens group and the second lens group and the change in the distance between the second lens group and the third lens group. It can be performed. In addition, by arranging the fourth lens group having negative refracting power and the fifth lens group having positive refracting power, the position of the exit pupil can be set appropriately, and the size of the first lens group to the fourth lens group can be reduced. . Therefore, it is advantageous to construct a small and inexpensive zoom lens.

  In the zoom lens according to the present embodiment, it is necessary to realize a zoom system suitable for noise reduction during zooming, and it is required to reduce the number of moving groups during zooming and to reduce weight. Therefore, in this embodiment, the first lens group and the aperture stop are fixed, the second lens group and the third lens group are moved, and the distance between each lens group and the aperture stop is changed to change the zoom ratio. And image position adjustment are performed.

  The fourth lens unit having a negative refractive power is advantageous in reducing the weight and securing the focus sensitivity (enabling focusing with a small amount of movement). In addition, when the fourth lens group is extended, the incident height of the principal ray off-axis in the fourth lens group becomes low and the angle of the principal ray toward the fifth lens group with respect to the optical axis becomes small. Since the distance between the fourth lens group and the fifth lens group is increased, the change in the incident height of the principal ray off-axis on the imaging surface can be reduced, and the change in magnification can be reduced. Therefore, by making the fourth lens group a focusing lens group, it is easy to suppress a change in magnification due to movement, and a change in magnification in a focusing (and further wobbling) operation can be suppressed.

  Conditional expression (1) relates to preferable refractive powers of the first lens group and the fourth lens group.

  By securing the refractive power of the fourth lens group so as not to fall below the lower limit value of conditional expression (1), the amount of movement of the fourth lens group during focusing (and further wobbling) can be reduced. Accordingly, the movable space can be reduced, which is advantageous for downsizing the entire zoom lens. Further, by suppressing the refractive power of the first lens group so as not to fall below the lower limit value, it is possible to suppress aberrations that occur in the first lens group and to reduce the number of constituent lenses.

  By suppressing the refractive power of the fourth lens group so as not to exceed the upper limit value of the conditional expression (1), it is possible to suppress aberration fluctuations accompanying focusing while reducing the number of constituent lenses of the fourth lens group. In addition, by ensuring the refractive power of the first lens group so as not to exceed the upper limit, the overall length of the zoom lens can be shortened, which is advantageous for downsizing.

  In the zoom lens according to the present embodiment, it is more preferable that at least one of the following constituent requirements, and more than one, are simultaneously satisfied.

  At the time of zooming from the wide-angle end to the telephoto end, at least the positions of the first lens group, the aperture stop, and the fifth lens group are fixed, and the second lens group, the third lens group, and the fourth are It is preferable to move in the optical axis direction.

  By using the first lens group and the fifth lens group as the fixed lens group, it becomes easy to reduce noise noise caused by the movement of the second, third, and fourth lens groups. In addition, it is preferable that the number of driving lens groups be suppressed by moving the fourth lens group both during focusing and during zooming.

It is preferable that the following conditional expressions (2) and (3) are satisfied in the in-focus state at the wide angle end.
| Y1′−y1 | / Δs <0.35 (2)
| Y0.7′−y0.7 | / Δs <0.35 (3)
However,
y1 is the maximum image height on the imaging surface,
y0.7 is 0,7 times the maximum image height y1,
y1 ′ is a field angle of view that reaches the image height of y1 when focused at infinity when the fourth lens group is moved with respect to an object at infinity and a defocus amount of Δs is generated from when focused at infinity. The ray height at the position where the chief ray of the same angle of view intersects the imaging surface,
y0.7 ′ is the image height of y0.7 when focusing on infinity when the fourth lens unit is moved with respect to an object at infinity and a defocus amount of Δs is generated from focusing on infinity. The ray height at the position where the principal ray of the same angle of view as the shooting angle of view intersects the imaging surface,
Δs is 8 * maximum image height y1 / 1000,
And
The unit of y1, y0.7, y1 ', y0.7' and Δs are all mm.
It is.

  In the zoom lens according to the present embodiment, it is necessary to realize a focus method in consideration of high-speed driving of the focus lens group (further, wobbling in moving image shooting), and weight reduction of the focus lens group is required. Therefore, in the present embodiment, focusing (and wobbling) is performed by the fourth lens group.

  With such a configuration, the zoom lens of the present embodiment has a smaller change in image magnification during focusing (and wobbling during moving image shooting) than the conventional zoom lens. The amount of change in image magnification varies depending on the height of the image, but a specific image height alone is not sufficient, and the amount of change must be reduced over the entire screen.

  Conditional expression (2) and conditional expression (3) are conditional expressions for that purpose, and define the condition of the image magnification change amount with respect to the defocus amount. Here, although it varies depending on the value of the defocus amount Δs, here, the calculation is performed with the defocus amount corresponding to the allowable depth. In general, the permissible depth can be expressed by F number * permissible circle of confusion, but in this embodiment, F number = 8 and permissible circle of confusion = maximum image height (y1) / 1000.

  In order not only to satisfy one of the conditional expression (2) and the conditional expression (3) but also to reduce the amount of change in the entire screen as in the present invention, the conditional expressions (2) and (3) Both formulas must be satisfied. Further, it has been found that by satisfying both the conditional expressions (2) and (3), the change in image magnification can be kept small even in other image heights and focal length states. Exceeding the upper limit values of conditional expression (2) and conditional expression (3) is not preferable because the amount of change in image magnification increases.

  FIG. 1 is a schematic diagram for explaining the definition of conditional expressions for the zoom lens according to the present embodiment. For convenience of explanation, the lens shape and the number of lenses in the first to fifth lens groups are described in a simplified manner, and the movement amount and optical path of the fourth lens group assuming wobbling are exaggerated.

  The zoom lens according to this embodiment includes, in order from the object side to the image side (imaging surface), 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 group. A fourth lens group having a refractive power and a fifth lens group having a positive refractive power can be used.

  In the figure, a light ray A indicates a principal light ray that is incident on the position of the maximum image height (y1) on the imaging surface when focusing on infinity. A light beam B indicates a principal light beam that is incident at a position 0.7 times (y0.7) the maximum image height (y1) of the imaging surface when focusing on infinity.

  The zoom lens according to the present embodiment is characterized in that focusing or wobbling is performed by moving the fourth lens group. In the figure, the light ray A ′ shows the displacement state of the principal ray A when the fourth lens group is moved by focusing or wobbling and formed at a position separated from the imaging surface by a defocus amount ΔS. Has been.

  The light ray B ′ shows the displacement state of the principal light ray B when the fourth lens group is moved by focusing or wobbling so as to form an image at a position separated by the defocus amount ΔS from the imaging surface. ing. The defocus amount ΔS is 8 * maximum image height (y1) / 1000 as described above.

  The image height at which the light ray A 'forms on the imaging surface is defined as y1', and the image height at which the light beam B 'forms at the imaging surface is defined as y0.7'.

  The fourth lens unit having a negative refractive power is advantageous in reducing the weight and securing the focus sensitivity. In addition, when the fourth lens unit is extended, the height between the fourth and fifth lens units becomes large, but the incident height of the principal ray off-axis in the fourth lens unit becomes low, and the magnification change on the imaging surface Therefore, it is easy to suppress a change in magnification due to the movement of the fourth lens group, and a change in magnification in a focusing (or wobbling) operation can be suppressed. This is particularly advantageous when shooting moving images. Also, when focusing from a long distance to a short distance is performed by moving the fourth lens group to the image side, a change in magnification on the imaging surface can be suppressed.

The maximum image height y1 on the imaging surface preferably satisfies the following conditional expression (A).
8.0 <y1 <25.0 (A)

  By ensuring the imaging area so as not to fall below the lower limit value of conditional expression (A), it becomes easy to prevent signal noise during high-sensitivity imaging. In addition, the amount of movement of the focusing (or wobbling) operation can be increased, and control becomes easy. In addition, it is easy to suppress an increase in the size of the zoom lens by preventing an increase in the imaging area so as not to exceed the upper limit value of the conditional expression (A). In addition, the lens that performs the focusing (and further wobbling) operation becomes smaller, and it becomes easier to suppress the power consumption during the operation.

  As described above, the fourth lens group may be a lens group that moves not only in focusing but also in the optical axis direction before focusing.

  The fourth lens group is not only focused but also a lens group that moves by wobbling in the optical axis direction before focusing, so that the in-focus state can be maintained, which is particularly advantageous when shooting moving images.

  The fourth lens group preferably has one positive lens and one negative lens, and the total number of lenses in the fourth lens group is preferably two.

  By canceling out aberrations between the positive lens and the negative lens while reducing the weight of the fourth lens group, it is advantageous in reducing various aberrations in the fourth lens group.

It is preferable that the following conditional expression (4) is satisfied.
0.20 <Σ1G / Σ2G <1.00 (4)
However,
Σ1G is the thickness of the first lens group on the optical axis,
Σ2G is the thickness of the second lens group on the optical axis,
It is.

  Conditional expression (4) relates to a preferable thickness on the optical axis of the first lens group and the second lens group. Setting the thickness of the first lens group on the optical axis appropriately so as not to fall below the lower limit of conditional expression (4) is advantageous for correcting the aberration of the first lens group. By appropriately setting the thickness of the first lens group on the optical axis so as not to exceed the upper limit value of conditional expression (4), it is possible to prevent the first lens group from becoming large.

It is preferable that the following conditional expression (5) is satisfied.
0.03 <Σ1G / f1 <0.23 (5)
However,
Σ1G is the thickness of the first lens group on the optical axis,
f1 is the focal length of the first lens group,
It is.

  Conditional expression (5) relates to the preferred thickness and refractive power of the first lens group on the optical axis.

  By securing the refractive power of the first lens unit so as not to fall below the lower limit value of conditional expression (5), the overall length of the zoom lens can be shortened, which is advantageous for downsizing.

  By appropriately setting the thickness of the first lens group on the optical axis so as not to exceed the upper limit value of conditional expression (5), it is possible to prevent the first lens group from becoming large. Further, by suppressing the refractive power of the first lens group so as not to exceed the upper limit value, it is possible to suppress aberrations that occur in the first lens group and to reduce the number of constituent lenses.

It is preferable that the following conditional expression (6) is satisfied.
Σ1G5G / y1 <15.9 (6)
However,
Σ1G5G is the thickness on the optical axis from the object side surface of the first lens group to the image side surface of the fifth lens group at the wide-angle end,
y1 is the maximum image height on the imaging surface,
It is.

  Conditional expression (6) relates to a preferable thickness of the first to fifth lens groups on the optical axis. By appropriately setting the thickness on the optical axis of the first lens group to the fifth lens group so as not to exceed the upper limit value of conditional expression (6), it is possible to prevent the zoom lens from becoming large.

It is preferable that the following conditional expression (7) is satisfied.
0.50 <d2G / fw <5.00 (7)
However,
d2G is the amount of movement of the second lens group at the time of zooming from the wide-angle end to the telephoto end, and the movement toward the image side is a positive sign.
fw is the focal length of the entire zoom lens system at the wide-angle end,
It is.

  Conditional expression (7) relates to the amount of movement of the second lens group upon zooming from the preferred wide-angle end to the telephoto end.

  By appropriately setting the amount of movement during zooming of the second lens group so that it does not fall below the lower limit of conditional expression (7), the zoom ratio and the first burden that are mainly borne by the movement of the second lens group are set. The zoom ratio burdened by the movement of the three lens groups can be appropriately distributed, the increase in the amount of movement of the third lens group can be prevented, and this is advantageous in reducing the overall length of the zoom lens.

  By appropriately setting the movement amount at the time of zooming of the second lens group so as not to exceed the upper limit value of the conditional expression (7), an increase in the movement amount of the second lens group can be prevented, and the zoom lens This is advantageous for downsizing the overall length.

  In addition, the second lens group includes four lenses of a first negative lens, a second negative lens, a first positive lens, and a second positive lens in order from the object side to the image side. Alternatively, the first negative lens, the second negative lens, the first positive lens, and the third negative lens are preferably included.

  Constituting with four lenses in this way is advantageous for reducing aberrations occurring in the second lens group, and is advantageous in securing a zoom ratio and the like because the principal point can be made more than that of the first lens group.

  The third lens group includes four lenses, a first positive lens, a second positive lens, a first negative lens, and a third positive lens in order from the object side to the image side. Alternatively, the third lens group includes five lenses including a first positive lens, a second positive lens, a first negative lens, a second negative lens, and a third positive lens. It is preferable that at least two of the lenses are cemented with each other.

  In this way, by using four lenses or five lenses, the refractive power arrangement of the lenses in the third lens group can be made symmetric while the principal point is on the object side, and aberrations occurring in the third lens group. It is advantageous for reduction of

  Further, including a cemented lens is advantageous in reducing chromatic aberration.

  Further, it is preferable that the fifth lens group is composed of one positive lens or two lenses of one positive lens and one negative lens.

  Using a single fifth lens group is advantageous in reducing the size of the fifth lens group. Alternatively, by forming two fifth lens groups, aberrations are canceled between the positive lens and the negative lens, which is advantageous in reducing various aberrations in the fifth lens group.

  Further, at the telephoto end with respect to the wide-angle end, the second lens group is located on the image side, the third lens group is located on the object side, the fourth lens group is located on the object side, It is preferable that an interval between the fourth lens group is widened and an interval between the fourth lens group and the fifth lens group is widened.

  Although the zoom function can be secured by the second and third lens groups and the image plane position can be adjusted by the fourth lens group, the movement of the fourth lens group during focusing can be performed by using the above-described moving method. The range can be secured at the telephoto end, which is advantageous for focusing to a short distance.

Moreover, it is preferable that the following conditional expressions (8) and (9) are satisfied.
4.6 <ft / fw <12.5 (8)
35 ° <ωw <50 ° (9)
However,
fw is the focal length of the entire zoom lens system when focusing at infinity at the wide angle end,
ft is the focal length of the entire zoom lens at the telephoto end at infinity,
ωw is the maximum half angle of view when focusing at infinity at the wide angle end.

  Conditional expression (8) and conditional expression (9) specify preferred specifications when using the zoom lens of the present embodiment.

  Conditional expression (8) specifies a preferable zoom ratio. Ensuring a zoom ratio so as not to fall below the lower limit is preferable because it can be used for various shooting scenes. By not exceeding the upper limit, it is advantageous for reducing aberration fluctuations and ensuring the brightness at the telephoto end.

  Conditional expression (9) specifies a preferred half angle of view at the wide-angle end. It is preferable to secure the angle of view so as not to fall below the lower limit. By appropriately suppressing the angle of view so as not to exceed the upper limit, it is advantageous for reducing off-axis aberrations.

  The imaging apparatus according to the present embodiment preferably includes any of the zoom lenses described above and an imaging element having an imaging surface that converts an optical image into an electrical signal.

  Each of the above-described configurations is a configuration at the time of focusing on infinity unless otherwise indicated in the definition. It is more preferable that a plurality of the above configurations are satisfied at the same time.

  In each conditional expression, it is more preferable to set the upper limit value or the lower limit value as follows. By adopting such an upper limit value or lower limit value, the above-described effects can be further enhanced.

For conditional expression (1), it is more preferable to set the lower limit to −0.33.
More preferably, the upper limit value is -0.10.

Conditional expressions (2) and (3) have strict observation conditions, and in order to obtain a good moving image even when observed on a large-screen TV or the like, the following conditional expressions are in focus at infinity at the wide-angle end. More preferably, the lower limit of one or both of (2) and (3) is 0.29.

In conditional expression (4), it is more preferable to let the lower limit value to be 0.31.
More preferably, the upper limit value is 0.87.

For conditional expression (5), it is more preferable to set the lower limit to 0.05.
More preferably, the upper limit is 0.21.

More preferably, the upper limit of conditional expression (6) is 14.1.

For conditional expression (7), it is more preferable to set the lower limit value to 0.97.
More preferably, the upper limit is 4.10.

For conditional expression (A), it is more preferable to set the lower limit to 9.5.
More preferably, the upper limit is 18.0.

  According to the present invention, it is possible to provide a zoom lens and an imaging apparatus that are small and suitable for moving image shooting.

It is a schematic diagram for demonstrating the definition of the conditional expression in the zoom lens of this embodiment. FIG. 3 is a cross-sectional view taken along the optical axis of the zoom lens according to the first exemplary embodiment. FIG. 6 is a cross-sectional view taken along the optical axis by developing the zoom lens of Example 2. FIG. 6 is a cross-sectional view taken along the optical axis by developing the zoom lens of Example 3. FIG. 9 is a cross-sectional view taken along the optical axis by developing the zoom lens of Example 4. FIG. 10 is a cross-sectional view taken along the optical axis by developing the zoom lens of Example 5. FIG. 9 is a cross-sectional view taken along the optical axis by developing the zoom lens of Example 6. FIG. 10 is a cross-sectional view taken along the optical axis of the zoom lens of Example 7. FIG. 6 is an aberration diagram of the zoom lens according to Example 1; FIG. 6 is an aberration diagram of the zoom lens according to Example 1; FIG. 6 is an aberration diagram of the zoom lens according to Example 2; FIG. 6 is an aberration diagram of the zoom lens according to Example 2; FIG. 6 is an aberration diagram of the zoom lens according to Example 3; FIG. 6 is an aberration diagram of the zoom lens according to Example 3; FIG. 6 is an aberration diagram of the zoom lens according to Example 4; FIG. 6 is an aberration diagram of the zoom lens according to Example 4; FIG. 10 is an aberration diagram of the zoom lens according to Example 5; FIG. 10 is an aberration diagram of the zoom lens according to Example 5; FIG. 10 is an aberration diagram of the zoom lens according to Example 6; FIG. 10 is an aberration diagram of the zoom lens according to Example 6; 10 is an aberration diagram of the zoom lens according to Example 7. FIG. 10 is an aberration diagram of the zoom lens according to Example 7. FIG. It is sectional drawing of the imaging device which used the zoom lens of this embodiment as an interchangeable lens. It is a front perspective view which shows the external appearance of the digital camera of this embodiment. It is a back perspective view showing the appearance of the digital camera of this embodiment. It is a block diagram which shows the control structure of the digital camera of this embodiment.

  Each embodiment shown below is a zoom lens that can be used for moving image shooting, as an interchangeable lens mounted on a camera body without a quick return mirror. This is a wide-angle / high-magnification zoom lens having a focal length in terms of an image surface of 35 mm, a wide-angle end of about 24-28 mm, and a zoom ratio of about 5-10 times.

  The zoom lenses according to the first to seventh embodiments of the present invention will be described with reference to the drawings. 2 to 8 are cross-sectional views taken along the optical axis of the zoom lenses according to the first to seventh embodiments of the present invention. In each figure, (a) shows the wide-angle end (WE), (b) shows the intermediate state (ST), and (c) shows the telephoto end (TE).

  FIG. 2 is a cross-sectional view of the zoom lens according to the first exemplary embodiment.

  This is a wide-angle / high-magnification zoom lens with a 35 mm equivalent focal length, a wide-angle end of 24 mm, and a zoom ratio of about 5 times.

  The zoom lens of Example 1 includes a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a third lens group G3 having a positive refractive power in order from the object side to the image side, as shown in FIG. The fourth lens group G4 has a negative refractive power and the fifth lens group G5 has a positive refractive power. In the figure, S indicates an aperture stop, I indicates an image plane, and C indicates a cover glass.

  The first lens group G1 includes, in order from the object side to the image side, a cemented lens SU11 of a negative meniscus lens L11 having a convex surface facing the object side and a positive meniscus lens L12 having a convex surface facing the object side.

  The second lens group G2, in order from the object side to the image side, a negative meniscus lens L21 having a convex surface directed toward the object side, a cemented lens SU21 of a biconcave negative lens L22 and a biconvex positive lens L23, and a biconvex positive lens L24. And consist of

  The third lens group G3 includes, in order from the object side to the image side, a biconvex positive lens L31, a biconvex positive lens L32, a biconcave negative lens L33, and a cemented lens SU31 of the biconvex positive lens L34.

  The fourth lens group G4 includes a biconcave negative lens L41 and a cemented lens SU41 of a positive meniscus lens L42 having a convex surface directed toward the object side.

  The fifth lens group G5 is composed of a biconvex positive lens L51.

  The operation of the zoom lens of Example 1 will be described. In the zoom operation, the first lens group G1, the aperture stop S, and the fifth lens group G5 are fixed, and the second lens group G2, the third lens group G3, and the fourth lens group G4 move independently.

  When zooming from the wide-angle end to the telephoto end, the second lens group G2 widens the distance from the first lens group G1 from the wide-angle end to the telephoto end, and narrows the distance from the stop S toward the image side. Moving. The third lens group G3 moves toward the object side from the wide-angle end to the telephoto end while narrowing the distance from the diaphragm S and widening the distance from the fourth lens group G4. The fourth lens group G4 moves toward the object side from the wide-angle end to the telephoto end while increasing the distance from the third lens group G3 and increasing the distance from the fifth lens group G5.

  The focus operation and the wobbling operation are performed by the fourth lens group G4. When focusing from infinity to a short distance, the fourth lens group G4 moves to the image side.

  The aspherical surfaces are the biconvex surfaces of the biconvex positive lens L24 of the second lens group G2 and the biconvex surfaces of the biconvex positive lens L31 of the third lens group G3 and the cemented lens SU31 of the third lens group G3. The image-side surface r17 of the positive lens L34 and the seven surfaces r22 and r22 of the biconvex positive lens L51 of the fifth lens group G5.

  FIG. 3 is a sectional view of the zoom lens according to the second embodiment.

  This is a wide-angle / high-magnification zoom lens with a 35 mm equivalent focal length, a wide-angle end of 24 mm, and a zoom ratio of about 5 times.

  As shown in the drawing, the zoom lens of Example 2 includes, in order from the object side to the image side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a third lens group G3 having a positive refractive power. The fourth lens group G4 has a negative refractive power and the fifth lens group G5 has a positive refractive power. In the figure, S indicates an aperture stop, I indicates an image plane, and C indicates a cover glass.

  The first lens group G1, in order from the object side to the image side, a negative meniscus lens L11 having a convex surface facing the object side, a cemented lens SU11 having a positive meniscus lens L12 having a convex surface facing the object side, and a convex surface facing the object side. And a positive meniscus lens L13.

  The second lens group G2 includes a negative meniscus lens L21 having a convex surface directed toward the object side, a cemented lens SU21 of a biconcave negative lens L22 and a biconvex positive lens L23, and a biconvex positive lens L24.

  The third lens group G3 includes, in order from the object side to the image side, a biconvex positive lens L31, a biconvex positive lens L32, a biconcave negative lens L33, and a cemented lens SU31 of the biconvex positive lens L34.

  The fourth lens group G4 includes a biconcave negative lens L41 and a cemented lens SU41 of a positive meniscus lens L42 having a convex surface directed toward the object side.

  The fifth lens group G5 is composed of a biconvex positive lens L51.

  The operation of the zoom lens of Example 2 will be described. In the zoom operation, the first lens group G1, the aperture stop S, and the fifth lens group G5 are fixed, and the second lens group G2, the third lens group G3, and the fourth lens group G4 move independently.

  When zooming from the wide-angle end to the telephoto end, the second lens group G2 widens the distance from the first lens group G1 from the wide-angle end to the telephoto end, and narrows the distance from the stop S toward the image side. Moving. The third lens group G3 moves toward the object side from the wide-angle end to the telephoto end while narrowing the distance from the diaphragm S and widening the distance from the fourth lens group G4. The fourth lens group G4 moves toward the object side from the wide-angle end to the telephoto end while increasing the distance from the third lens group G3 and increasing the distance from the fifth lens group G5.

  The focus operation and the wobbling operation are performed by the fourth lens group G4. When focusing from infinity to a short distance, the fourth lens group G4 moves to the image side.

  The aspherical surfaces are biconvex surfaces of the biconvex positive lens L24 of the second lens group G2, both surfaces r11 and r15 of the biconvex positive lens L31 of the third lens group G3, and the cemented lens SU31 of the third lens group G3. The image side surface r19 of the positive lens L34 and the seven surfaces r23 and r24 of the biconvex positive lens L51 of the fifth lens group G5.

  FIG. 4 is a sectional view of the zoom lens of Example 3.

  This is a wide-angle / high-magnification zoom lens with a 35 mm equivalent focal length, a wide-angle end of 24 mm, and a zoom ratio of about 6 times.

  As shown in the drawing, the zoom lens of Example 3 includes a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a third lens group G3 having a positive refractive power in order from the object side to the image side. The fourth lens group G4 has a negative refractive power and the fifth lens group G5 has a positive refractive power. In the figure, S indicates an aperture stop, I indicates an image plane, and C indicates a cover glass.

  The first lens group G1, in order from the object side to the image side, a negative meniscus lens L11 having a convex surface facing the object side, a cemented lens SU11 having a positive meniscus lens L12 having a convex surface facing the object side, and a convex surface facing the object side. And a positive meniscus lens L13.

  The second lens group G2 includes, in order from the object side to the image side, a negative meniscus lens L21 having a convex surface directed toward the object side, a cemented lens SU21 of a biconcave negative lens L22 and a biconvex positive lens L23, and a convex surface on the image side. Directed positive meniscus lens L24.

  The third lens group G3 includes, in order from the object side to the image side, a biconvex positive lens L31, a cemented lens SU31 including a biconvex positive lens L32 and a biconcave negative lens L33, and a negative meniscus lens L34 having a convex surface directed toward the object side. And a cemented lens SU32 of a biconvex positive lens L35.

  The fourth lens group G4 includes a cemented lens SU41 including a negative meniscus lens L41 having a convex surface directed toward the object side and a positive meniscus lens L42 having a convex surface directed toward the object side.

  The fifth lens group G5 is composed of a biconvex positive lens L51.

  The operation of the zoom lens of Example 3 will be described. In the zoom operation, the first lens group G1, the aperture stop S, and the fifth lens group G5 are fixed, and the second lens group G2, the third lens group G3, and the fourth lens group G4 move independently.

  When zooming from the wide-angle end to the telephoto end, the second lens group G2 widens the distance from the first lens group G1 from the wide-angle end to the telephoto end, and narrows the distance from the stop S toward the image side. Moving. The third lens group G3 moves toward the object side from the wide-angle end to the telephoto end while narrowing the distance from the diaphragm S and widening the distance from the fourth lens group G4. The fourth lens group G4 moves toward the object side from the wide-angle end to the telephoto end while increasing the distance from the third lens group G3 and increasing the distance from the fifth lens group G5.

  The focus operation and the wobbling operation are performed by the fourth lens group G4. When focusing from infinity to a short distance, the fourth lens group G4 moves to the image side.

  The aspherical surfaces are the image side surface r7 of the negative meniscus lens L21 of the second lens group G2, both surfaces r12 and r13 of the positive meniscus lens L24 of the second lens group G2, and both surfaces of the biconvex positive lens L31 of the third lens group G3. r15, r16, the image side surface r22 of the biconvex positive lens L35 of the cemented lens SU32 of the third lens group G3, and the eight surfaces r26, r27 of the biconvex positive lens L51 of the fifth lens group G5.

  FIG. 5 is a cross-sectional view of the zoom lens of Example 4.

  This is a wide-angle / high-magnification zoom lens with a 35 mm equivalent focal length, a wide-angle end of 24 mm, and a zoom ratio of about 7 times.

  As shown in the drawing, the zoom lens of Example 4 includes, in order from the object side to the image side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a third lens group G3 having a positive refractive power. The fourth lens group G4 has a negative refractive power and the fifth lens group G5 has a positive refractive power. In the figure, S indicates an aperture stop, I indicates an image plane, and C indicates a cover glass.

  The first lens group G1 includes, in order from the object side to the image side, a cemented lens SU11 of a negative meniscus lens L11 having a convex surface facing the object side and a positive meniscus lens L12 having a convex surface facing the object side.

  The second lens group G2, in order from the object side to the image side, has a negative meniscus lens L21 having a convex surface directed toward the object side, a cemented lens SU21 of a biconcave negative lens L22 and a biconvex positive lens L23, and a convex surface on the object side. Directed positive meniscus lens L24.

  The third lens group G3 includes, in order from the object side to the image side, a biconvex positive lens L31, a biconvex positive lens L32, a biconcave negative lens L33, and a cemented lens SU31 of the biconvex positive lens L34.

  The fourth lens group G4 includes a cemented lens SU41 including a positive meniscus lens L41 having a convex surface directed toward the image side and a biconcave negative lens L42.

  The fifth lens group G5 includes a biconvex positive lens L51 and a biconcave negative lens L52.

  The operation of the zoom lens of Example 4 will be described. In the zoom operation, the first lens group G1, the aperture stop S, and the fifth lens group G5 are fixed, and the second lens group G2, the third lens group G3, and the fourth lens group G4 move independently.

  When zooming from the wide-angle end to the telephoto end, the second lens group G2 widens the distance from the first lens group G1 from the wide-angle end to the telephoto end, and narrows the distance from the stop S toward the image side. Moving. The third lens group G3 moves toward the object side from the wide-angle end to the telephoto end while narrowing the distance from the diaphragm S and widening the distance from the fourth lens group G4. The fourth lens group G4 moves from the wide-angle end to the intermediate state, moves toward the object side while widening the distance from the third lens group G3, widening the distance from the fifth lens group G5, and moves from the intermediate state to the telephoto end. The distance from the third lens group G3 is increased, the distance from the fifth lens group G5 is decreased, and the image side is moved.

  The focus operation and the wobbling operation are performed by the fourth lens group G4. When focusing from infinity to a short distance, the fourth lens group G4 moves to the image side.

  The aspheric surfaces are both surfaces r9 and r10 of the positive meniscus lens L24 of the second lens group G2, both surfaces r12 and r13 of the biconvex positive lens L31 closest to the object side of the third lens group G3, and the cemented lens SU31 of the third lens group G3. The image-side surface r17 of the most image-side biconvex positive lens L34, the image-side surface r20 of the biconcave negative lens L42 of the cemented lens SU41 of the fourth lens group G4, and the biconvex positive lens of the fifth lens group G5 Eight surfaces of both sides r21 and r22 of L51.

  FIG. 6 is a cross-sectional view of the zoom lens of Example 5.

  This is a wide-angle / high-magnification zoom lens with a 35 mm equivalent focal length, a wide-angle end of 24 mm, and a magnification ratio of about 8 times.

  As shown in the drawing, the zoom lens of Example 5 includes, in order from the object side to the image side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a third lens group G3 having a positive refractive power. The fourth lens group G4 has a negative refractive power and the fifth lens group G5 has a positive refractive power. In the figure, S indicates an aperture stop, I indicates an image plane, and C indicates a cover glass.

  The first lens group G1 includes, in order from the object side to the image side, a cemented lens SU11 of a negative meniscus lens L11 having a convex surface facing the object side and a positive meniscus lens L12 having a convex surface facing the object side.

  The second lens group G2, in order from the object side to the image side, has a negative meniscus lens L21 having a convex surface directed toward the object side, a cemented lens SU21 of a biconcave negative lens L22 and a biconvex positive lens L23, and a convex surface on the object side. Directed positive meniscus lens L24.

  The third lens group G3 includes, in order from the object side to the image side, a biconvex positive lens L31, a biconvex positive lens L32, a biconcave negative lens L33, and a cemented lens SU31 of the biconvex positive lens L34.

  The fourth lens group G4 includes a cemented lens SU41 including a positive meniscus lens L41 having a convex surface directed toward the image side and a biconcave negative lens L42.

  The fifth lens group G5 includes a biconvex positive lens L51 and a biconcave negative lens L52.

  The operation of the zoom lens of Example 5 will be described. In the zoom operation, the first lens group G1, the aperture stop S, and the fifth lens group G5 are fixed, and the second lens group G2, the third lens group G3, and the fourth lens group G4 move independently.

  When zooming from the wide-angle end to the telephoto end, the second lens group G2 widens the distance from the first lens group G1 from the wide-angle end to the telephoto end, and narrows the distance from the stop S toward the image side. Moving. The third lens group G3 moves toward the object side from the wide-angle end to the telephoto end while narrowing the distance from the diaphragm S and widening the distance from the fourth lens group G4. The fourth lens group G4 moves toward the object side from the wide-angle end to the telephoto end while increasing the distance from the third lens group G3 and increasing the distance from the fifth lens group G5.

  The focus operation and the wobbling operation are performed by the fourth lens group G4. When focusing from infinity to a short distance, the fourth lens group G4 moves to the image side.

  The aspheric surfaces are both surfaces r9 and r10 of the positive meniscus lens L24 of the second lens group G2, both surfaces r12 and r13 of the biconvex positive lens L31 closest to the object side of the third lens group G3, and the cemented lens SU31 of the third lens group G3. The image-side surface r18 of the most image-side biconvex positive lens L34, the image-side surface r21 of the biconcave negative lens L42 of the cemented lens SU41 of the fourth lens group G4, and the biconvex positive lens of the fifth lens group G5 Eight surfaces of both sides r22 and r23 of L51.

  FIG. 7 is a sectional view of the zoom lens of Example 6.

  This is a wide-angle / high-magnification zoom lens with a 35 mm equivalent focal length, a wide-angle end of 24 mm, and a zoom ratio of about 10 times.

  As shown in the drawing, the zoom lens of Example 6 includes, in order from the object side to the image side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a third lens group G3 having a positive refractive power. The fourth lens group G4 has a negative refractive power and the fifth lens group G5 has a positive refractive power. In the figure, S indicates an aperture stop, I indicates an image plane, and C indicates a cover glass.

  The first lens group G1 includes, in order from the object side to the image side, a cemented lens SU11 of a negative meniscus lens L11 having a convex surface facing the object side and a positive meniscus lens L12 having a convex surface facing the object side.

  The second lens group G2 includes, in order from the object side to the image side, a negative meniscus lens L21 having a convex surface directed toward the object side, a biconcave negative lens L22, a biconvex positive lens L23, and a negative meniscus having a convex surface directed toward the image side. And a cemented lens SU21 of the lens L24.

  The third lens group G3 includes, in order from the object side to the image side, a biconvex positive lens L31, a biconvex positive lens L32, a biconcave negative lens L33, and a cemented lens SU31 of the biconvex positive lens L34.

  The fourth lens group G4 includes a cemented lens SU41 including a negative meniscus lens L41 having a convex surface directed toward the object side and a positive meniscus lens L42 having a convex surface directed toward the object side.

  The fifth lens group G5 is composed of a biconvex positive lens L51.

  The operation of the zoom lens of Example 6 will be described. In the zoom operation, the first lens group G1, the aperture stop S, and the fifth lens group G5 are fixed, and the second lens group G2, the third lens group G3, and the fourth lens group G4 move independently.

  When zooming from the wide-angle end to the telephoto end, the second lens group G2 widens the distance from the first lens group G1 from the wide-angle end to the telephoto end, and narrows the distance from the stop S toward the image side. Moving. The third lens group G3 moves toward the object side from the wide-angle end to the telephoto end while narrowing the distance from the diaphragm S and widening the distance from the fourth lens group G4. The fourth lens group G4 moves toward the object side from the wide-angle end to the telephoto end while increasing the distance from the third lens group G3 and increasing the distance from the fifth lens group G5.

  The focus operation and the wobbling operation are performed by the fourth lens group G4. When focusing from infinity to a short distance, the fourth lens group G4 moves to the image side.

  The aspherical surfaces include both surfaces r6 and r7 of the biconcave negative lens L22 of the second lens group G2, both surfaces r13 and r14 of the biconvex positive lens L31 closest to the object side of the third lens group G3, and a cemented lens of the third lens group G3. These are the seven surfaces of the image side surface r18 of the biconvex positive lens L34 closest to the image side of SU31 and both surfaces r22 and r23 of the biconvex positive lens L51 of the fifth lens group G5.

  FIG. 8 is a sectional view of the zoom lens according to the seventh embodiment.

  This is a wide-angle / high-magnification zoom lens with a 35 mm equivalent focal length, a wide-angle end of 28 mm, and a zoom ratio of about 5 times.

  As shown in the drawing, the zoom lens of Example 7 includes a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a third lens group G3 having a positive refractive power in order from the object side to the image side. The fourth lens group G4 has a negative refractive power and the fifth lens group G5 has a positive refractive power. In the figure, S indicates an aperture stop, I indicates an image plane, and C indicates a cover glass.

  The first lens group G1 includes, in order from the object side to the image side, a cemented lens SU11 of a negative meniscus lens L11 having a convex surface facing the object side and a positive meniscus lens L12 having a convex surface facing the object side.

  The second lens group G2, in order from the object side to the image side, has a negative meniscus lens L21 having a convex surface directed toward the object side, a cemented lens SU21 of a biconcave negative lens L22 and a biconvex positive lens L23, and a convex surface on the object side. Directed positive meniscus lens L24.

  The third lens group G3 includes, in order from the object side to the image side, a biconvex positive lens L31, a cemented lens SU31 including a biconvex positive lens L32 and a biconcave negative lens L33, and a negative meniscus lens L34 having a convex surface directed toward the object side. And a cemented lens SU32 of a biconvex positive lens L35.

  The fourth lens group G4 includes a cemented lens SU41 including a negative meniscus lens L41 having a convex surface directed toward the object side and a positive meniscus lens L42 having a convex surface directed toward the object side.

  The fifth lens group G5 includes a positive meniscus lens L51 having a convex surface directed toward the object side.

  The operation of the zoom lens of Example 7 will be described. In the zoom operation, the first lens group G1, the aperture stop S, and the fifth lens group G5 are fixed, and the second lens group G2, the third lens group G3, and the fourth lens group G4 move independently.

  When zooming from the wide-angle end to the telephoto end, the second lens group G2 widens the distance from the first lens group G1 from the wide-angle end to the telephoto end, and narrows the distance from the stop S toward the image side. Moving. The third lens group G3 moves toward the object side from the wide-angle end to the telephoto end while narrowing the distance from the diaphragm S and widening the distance from the fourth lens group G4. The fourth lens group G4 moves toward the object side from the wide-angle end to the telephoto end while increasing the distance from the third lens group G3 and increasing the distance from the fifth lens group G5.

  The focus operation and the wobbling operation are performed by the fourth lens group G4. When focusing from infinity to a short distance, the fourth lens group G4 moves to the image side.

  The aspheric surfaces are both surfaces r9 and r10 of the positive meniscus lens L24 of the second lens group G2, both surfaces r12 and r13 of the biconvex positive lens L31 closest to the object side of the third lens group G3, and the image side of the third lens group G3. 5 surfaces of the image side surface r19 of the biconvex positive lens L34 of the cemented lens SU32.

  Various numerical data (surface data, aspheric surface data, variable interval data, various data 1, various data 2) of the above-described first to seventh embodiments are shown below.

  The surface data includes, for each surface number, the radius of curvature r of each lens surface (optical surface), the surface interval d, the refractive index nd of each lens (optical medium) with respect to the d-line (587.6 nm), and each lens (optical medium). The Abbe number νd of the d line is shown. The unit of the radius of curvature r and the surface interval d is millimeters (mm). In the surface data, “∞” described in the radius of curvature indicates infinite.

In the aspherical surface data, data relating to a lens surface having an aspherical shape in the surface data is shown. The aspherical shape is expressed by the following equation, where x is an optical axis with the light traveling direction being positive, and y is a direction orthogonal to the optical axis.
x = (y ² / r) / [1+ {1− (1 + K) · (y / r) ² } ^1/2 ]
^{+ A4y 4 + A6y 6 + A8y} 8 + A10y 10 ...

Here, r is a paraxial radius of curvature, K is a conical coefficient, and A4, A6, A8, and A10 are fourth-order, sixth-order, eighth-order, and tenth-order aspheric coefficients, respectively. The symbol “E” indicates that the subsequent numerical value is a power exponent with 10 as the base. For example, “1.0E-5” means “1.0 × 10 ⁻⁵ ”.

  Various data 1 shows various zoom data at the wide-angle end (WE), intermediate (ST), and telephoto end (TE). The zoom data includes a focal length, an F number (Fno), an angle of view (2ω), an image height, a back focus (BF), and a variable surface interval d. Various data 2 shows focal lengths f1 to f5 in the first to fifth lens groups.

Numerical example 1
Surface number r d nd νd
1 56.912 1.40 1.84666 23.78
2 45.147 6.69 1.72916 54.68
3 283.392 D3 (variable)
4 111.625 1.20 1.83481 42.71
5 13.602 8.52
6 -34.083 1.10 1.78800 47.37
7 28.705 5.46 1.84666 23.78
8 -132.078 0.10
9 (Aspherical) 82.320 2.98 1.52542 55.78
10 (Aspherical) -127.407 D10 (variable)
11 (aperture) ∞ D11 (variable)
12 (Aspherical) 14.782 4.64 1.49700 81.54
13 (Aspherical surface) -58.889 0.10
14 16.190 4.52 1.51633 64.14
15 -71.730 1.35 1.88300 40.76
16 10.334 4.77 1.49700 81.54
17 (Aspherical) -26.510 D17 (variable)
18 -589.551 1.00 1.80400 46.57
19 9.438 2.06 1.84666 23.78
20 13.756 D20 (variable)
21 (Aspherical) 30.356 3.90 1.51633 64.14
22 (Aspherical surface) -70.714 13.40
23 ∞ 4.00 1.51633 64.14
24 ∞ 0.8
Image plane ∞

Aspheric coefficient 9th surface
K = 0.000, A4 = 4.81480E-05, A6 = -9.50101E-08, A8 = 3.10123E-09, A10 = -1.06248E-11
10th page
K = 0.000, A4 = 3.17860E-05, A6 = -5.95034E-08, A8 = 3.20925E-09, A10 = -1.28394E-11
12th page
K = 0.000, A4 = -2.14397E-05, A6 = 3.59448E-07, A8 = -7.60025E-09, A10 = 5.16822E-11
13th page
K = 0.000, A4 = 1.62633E-05, A6 = 4.03049E-07, A8 = -9.70801E-09, A10 = 6.87773E-11
17th page
K = 0.000, A4 = 6.31351E-05, A6 = 4.29315E-07, A8 = 1.99802E-10, A10 = 6.12862E-11
21st page
K = 0.000, A4 = 3.73857E-05, A6 = -2.93542E-07, A8 = 1.94813E-09, A10 = -1.45331E-11
22nd page
K = 0.000, A4 = 3.31689E-05, A6 = -3.17518E-07, A8 = 1.80831E-09, A10 = -1.49415E-11

Various data 1
Zoom data
WE ST TE
Focal length 12.24 26.80 59.00
FNO. 4.01 4.86 5.73
Angle of view 2ω (°) 88.94 43.60 20.58
Image height 10.82 10.82 10.82

D3 0.80 16.31 26.27
D10 26.47 10.96 1.00
D11 20.11 10.70 1.00
D17 1.80 4.15 10.07
D20 2.17 9.23 13.01

fb (in air) 16.84 16.84 16.84
Full length (in air) 117.98 117.98 117.98

Various data 2
f1 101.20
f2 -18.57
f3 19.33
f4 -17.18
f5 41.68

Numerical example 2
Surface number r d nd νd
1 96.811 1.40 1.84666 23.78
2 69.422 4.11 1.72916 54.68
3 222.222 0.10
4 73.312 3.45 1.72916 54.68
5 191.343 D5 (variable)
6 113.125 1.20 1.81600 46.62
7 13.921 8.22
8 -28.374 1.10 1.72916 54.68
9 28.382 4.92 1.80518 25.46
10 -135.911 0.10
11 (Aspherical) 144.647 2.65 1.52542 55.78
12 (Aspherical) -87.751 D12 (variable)
13 (aperture) ∞ D13 (variable)
14 (Aspherical) 14.208 5.57 1.49700 81.54
15 (Aspherical surface) -42.724 0.10
16 18.612 3.77 1.51633 64.14
17 -40.104 1.30 1.88300 40.76
18 11.879 4.99 1.49700 81.54
19 (Aspherical surface) -21.633 D19 (variable)
20 -1106.045 1.00 1.80400 46.57
21 8.798 2.33 1.84666 23.78
22 12.922 D22 (variable)
23 (Aspherical) 33.845 3.91 1.51633 64.14
24 (Aspherical surface) -64.911 13.56
25 ∞ 4.00 1.51633 64.14
26 ∞ 0.80
Image plane ∞

Aspheric coefficient 11th surface
K = 0.000, A4 = 3.49846E-05, A6 = -3.03078E-07, A8 = 3.21587E-09, A10 = -7.90949E-12
12th page
K = 0.000, A4 = 2.13323E-05, A6 = -2.67929E-07, A8 = 3.30300E-09, A10 = -8.69171E-12
14th page
K = 0.000, A4 = -2.54966E-05, A6 = 3.51889E-07, A8 = -5.57102E-09, A10 = 4.09869E-11
15th page
K = 0.000, A4 = 3.29900E-05, A6 = 3.99726E-07, A8 = -7.40841E-09, A10 = 5.40404E-11
19th page
K = 0.000, A4 = 4.76112E-05, A6 = 5.89293E-07, A8 = -6.95406E-09, A10 = 1.44104E-10
23rd page
K = 0.000, A4 = 2.70587E-05, A6 = 2.77038E-09, A8 = 1.11660E-10, A10 = -1.28052E-11
24th page
K = 0.000, A4 = 1.62176E-05, A6 = -9.35316E-08, A8 = 1.26777E-09, A10 = -1.90964E-11

Various data 1
Zoom data
WE ST TE
Focal length 12.24 26.80 59.00
FNO. 4.02 4.86 5.73
Angle of view 2ω (°) 88.95 43.81 20.61
Image height 10.82 10.82 10.82

D5 0.80 15.09 25.4
D12 25.6 11.31 1.00
D13 19.74 9.81 1.01
D19 1.80 4.13 10.26
D22 2.42 10.02 12.69

fb (in air) 17.00 17.00 17.00
Full length (in air) 117.58 117.58 117.58

Various data 2
f1 100.48
f2 -17.74
f3 18.73
f4 -16.37
f5 43.67

Numerical Example 3
Surface number r d nd νd
1 146.544 2.00 1.84666 23.78
2 76.041 5.46 1.72916 54.68
3 512.855 0.20
4 40.028 5.44 1.72916 54.68
5 97.078 D5 (variable)
6 94.407 1.00 1.83481 42.71
7 (Aspherical) 12.244 8.11
8 -22.355 1.00 1.80400 46.57
9 37.360 0.00
10 37.386 4.32 1.84666 23.78
11 -46.164 0.25
12 (Aspherical surface) -53.373 3.07 1.52542 55.78
13 (Aspherical) -30.818 D13 (variable)
14 (aperture) ∞ D14 (variable)
15 (Aspherical) 20.113 4.67 1.49700 81.54
16 (Aspherical) -59.154 0.21
17 14.508 6.37 1.48749 70.23
18 -34.435 1.00 1.80400 46.57
19 345.953 0.20
20 84.143 0.80 1.80 100 34.97
21 10.618 4.51 1.49700 81.54
22 (Aspherical surface) -47.543 D22 (variable)
23 4726.944 1.00 1.88300 40.76
24 9.428 3.21 1.84666 23.78
25 17.732 D25 (variable)
26 (Aspherical) 28.620 5.30 1.51633 64.14
27 (Aspherical) -80.851 11.60
28 ∞ 4.00 1.51633 64.14
29 ∞ 0.80
Image plane ∞

Aspheric coefficient 7th surface
K = -0.209, A4 = 1.28579E-05, A6 = 6.33708E-08, A8 = 9.42400E-10, A10 = -4.73717E-13
12th page
K = 0.000, A4 = -4.46566E-06, A6 = 1.16292E-07, A8 = -6.99502E-09, A10 = 2.78931E-11
13th page
K = 0.000, A4 = -1.95000E-05, A6 = 3.33135E-08, A8 = -4.19987E-09, A10 = 1.82943E-11
15th page
K = 0.000, A4 = 2.14836E-06, A6 = 5.12283E-08, A8 = 3.70343E-10, A10 = 1.14231E-11
16th page
K = 0.000, A4 = 1.12620E-05, A6 = 3.57185E-08, A8 = -1.27090E-09, A10 = 2.71225E-11
22nd page
K = 0.000, A4 = 8.85246E-05, A6 = 5.51461E-07, A8 = -4.27979E-10, A10 = 1.16911E-11
26th page
K = 0.000, A4 = 1.10749E-05, A6 = 2.96257E-07, A8 = 1.27906E-09, A10 = 2.53195E-12
No. 27
K = 0.000, A4 = 1.42208E-05, A6 = 1.11588E-07, A8 = 1.91604E-09, A10 = 1.67268E-11

Various data 1
Zoom data
WE ST TE
Focal length 12.24 29.39 70.56
FNO. 4.08 4.85 5.77
Angle of view 2ω (°) 90.29 40.06 17.08
Image height 10.82 10.82 10.82

D5 0.20 14.34 23.11
D13 23.11 8.97 0.20
D14 19.83 10.53 0.20
D22 0.99 3.71 10.55
D25 1.91 8.49 11.98

fb (in air) 15.04 15.04 15.04
Total length (in air) 119.18 119.18 119.18

Various data 2
f1 72.33
f2 -16.38
f3 20.10
f4 -19.34
f5 41.62

Numerical Example 4
Surface number r d nd νd
1 55.076 1.40 1.84666 23.78
2 35.547 6.68 1.80400 46.57
3 170.821 D3 (variable)
4 107.113 1.20 1.88300 40.76
5 14.000 8.48
6 -68.521 1.10 1.88300 40.76
7 20.873 5.80 1.84666 23.78
8 -99.606 0.10
9 (Aspherical) 551.574 2.80 1.73310 48.90
10 (Aspherical) 2584.679 D10 (variable)
11 (aperture) ∞ D11 (variable)
12 (Aspherical) 16.970 5.07 1.49700 81.54
13 (Aspherical surface) -44.281 0.33
14 21.450 3.67 1.51633 64.14
15 -161.750 1.80 1.88300 40.76
16 11.765 6.30 1.49700 81.54
17 (Aspherical surface) -21.113 D17 (variable)
18 -392.081 2.40 1.84666 23.78
19 -17.145 1.00 1.76802 49.24
20 (Aspherical) 13.049 D20 (variable)
21 (Aspherical surface) 21.911 7.24 1.58913 61.25
22 (Aspherical) -16.189 0.10
23 -22.665 1.60 1.91082 35.25
24 109.965 13.70
25 ∞ 4.00 1.51633 64.14
26 ∞ 0.80
Image plane ∞

Aspheric coefficient 9th surface
K = 0.000, A4 = 5.66744E-08, A6 = -1.13783E-08, A8 = 9.08541E-10, A10 = -6.23873E-12, A12 = 1.37746E-14
10th page
K = 0.000, A4 = -1.26421E-05, A6 = -5.69417E-08, A8 = 1.14139E-09, A10 = -8.18677E-12, A12 = 1.66328E-14
12th page
K = 0.000, A4 = -2.67354E-05, A6 = 3.67269E-07, A8 = -6.65269E-09, A10 = 5.50236E-11, A12 = -1.54305E-13
13th page
K = 0.000, A4 = 2.06837E-05, A6 = 5.53783E-07, A8 = -9.88399E-09, A10 = 8.14377E-11, A12 = -2.27579E-13
17th page
K = 0.000, A4 = 1.78718E-05, A6 = -3.57782E-07, A8 = 7.19229E-09, A10 = -5.40603E-11
20th page
K = 0.000, A4 = -4.67726E-06, A6 = 3.78195E-07, A8 = -1.15641E-08, A10 = 7.88096E-11
21st page
K = 0.000, A4 = 1.83991E-06, A6 = 2.19003E-07, A8 = -3.50794E-09, A10 = 4.37525E-11, A12 = -2.07999E-13
22nd page
K = 0.000, A4 = 3.44691E-05, A6 = 7.33532E-08, A8 = 1.00896E-09, A10 = 6.33402E-12, A12 = -8.66586E-14

Various data 1
Zoom data
WE ST TE
Focal length 12.24 30.00 81.99
FNO. 4.04 4.98 5.76
Angle of view 2ω (°) 88.91 40.54 14.95
Image height 10.82 10.82 10.82

D3 0.80 17.09 32.78
D10 32.98 16.69 1.00
D11 24.00 10.09 1.01
D17 1.80 4.63 14.17
D20 3.14 14.22 13.76

fb (in air) 17.14 17.14 17.14
Total length (in air) 136.92 136.92 136.92

Various data 2
f1 102.23
f2 -16.86
f3 20.36
f4 -17.70
f5 59.74

Numerical Example 5
Surface number r d nd νd
1 55.126 1.40 1.84666 23.78
2 35.205 6.86 1.77250 49.62
3 228.211 D3 (variable)
4 136.896 1.20 1.88300 40.76
5 14.538 8.27
6 -58.783 1.10 1.88300 40.76
7 20.768 5.76 1.84666 23.78
8 -110.576 0.10
9 (Aspherical surface) 89.717 2.80 1.51633 64.14
10 (Aspherical) 223.023 D10 (variable)
11 (aperture) ∞ D11 (variable)
12 (Aspherical) 18.085 4.91 1.49700 81.54
13 (Aspherical) -54.894 0.10
14 22.416 4.36 1.57099 50.80
15 -50.776 0.49
16 -79.214 1.10 1.88300 40.76
17 11.037 8.00 1.49700 81.54
18 (Aspherical) -21.647 D18 (variable)
19 -254.499 2.12 1.84666 23.78
20 -20.128 1.00 1.76802 49.24
21 (Aspherical) 12.987 D21 (variable)
22 (Aspherical) 20.490 7.80 1.58913 61.25
23 (Aspherical) -14.847 0.10
24 -21.609 2.00 1.91082 35.25
25 85.870 13.76
26 ∞ 4.00 1.51633 64.14
27 ∞ 0.80
Image plane ∞

Aspheric coefficient 9th surface
K = 0.000, A4 = -1.83811E-06, A6 = 6.23413E-08, A8 = 6.21338E-10, A10 = -7.56630E-12, A12 = 2.73135E-14
10th page
K = 0.000, A4 = -1.75480E-05, A6 = 1.60252E-08, A8 = 8.00977E-10, A10 = -8.44040E-12, A12 = 2.80324E-14
12th page
K = 0.000, A4 = -2.66818E-05, A6 = 3.79005E-07, A8 = -7.20215E-09, A10 = 5.48453E-11, A12 = -1.14768E-13
13th page
K = 0.000, A4 = 1.68285E-05, A6 = 5.34111E-07, A8 = -9.18940E-09, A10 = 6.93287E-11, A12 = -1.37197E-13
18th page
K = 0.000, A4 = 9.98745E-06, A6 = -4.82176E-07, A8 = 7.97302E-09, A10 = -7.66033E-11
21st page
K = 0.000, A4 = -1.23603E-05, A6 = 2.12617E-07, A8 = -1.02960E-08, A10 = 7.54788E-11
22nd page
K = 0.000, A4 = 1.16070E-05, A6 = 1.60956E-07, A8 = -1.95449E-09, A10 = 1.93458E-11, A12 = -4.17072E-14
23rd page
K = 0.000, A4 = 6.75676E-05, A6 = 2.36415E-07, A8 = -2.37286E-09, A10 = 3.13555E-11, A12 = -1.01627E-13

Various data 1
Zoom data
WE ST TE
Focal length 12.24 28.00 94.00
FNO. 4.04 5.02 5.80
Angle of view 2ω (°) 88.91 43.00 13.04
Image height 10.82 10.82 10.82

D3 0.80 14.64 33.06
D10 33.26 19.42 1.00
D11 29.02 13.51 1.00
D18 1.80 4.33 16.10
D21 2.02 15.00 15.74

fb (in air) 17.19 17.19 17.19
Total length (in air) 143.56 143.56 143.56

Various data 2
f1 98.96
f2 -16.86
f3 21.39
f4 -17.02
f5 55.09

Numerical Example 6
Surface number r d nd νd
1 52.938 2.00 1.84666 23.78
2 35.397 8.74 1.72916 54.68
3 205.359 D3 (variable)
4 252.878 1.50 1.88300 40.76
5 20.151 8.11
6 (Aspherical surface) -81.470 1.50 1.69350 53.21
7 (Aspherical surface) 59.489 0.15
8 47.395 7.27 1.76182 26.52
9 -38.211 0.28
10 -35.347 1.50 1.77250 49.60
11 357.963 D11 (variable)
12 (aperture) ∞ D12 (variable)
13 (Aspherical) 18.627 6.68 1.49700 81.54
14 (Aspherical) -30.289 3.95
15 57.730 6.11 1.48749 70.23
16 -49.426 1.00 1.90366 31.32
17 243.572 2.56 1.49700 81.54
18 (Aspherical) -41.942 D18 (variable)
19 104.757 1.00 1.91082 35.25
20 9.389 4.63 1.59270 35.31
21 17.696 D21 (variable)
22 (Aspherical surface) 37.781 3.32 1.58313 59.38
23 (Aspherical surface) -190.868 11.10
24 ∞ 4.00 1.51633 64.14
25 ∞ 0.80
Image plane ∞

Aspheric coefficient 6th surface
K = 0.000, A4 = 4.44432E-07, A6 = 7.90512E-09, A8 = 2.85908E-10, A10 = -9.77275E-13
7th page
K = 0.000, A4 = -2.62226E-06, A6 = 1.25820E-08, A8 = 1.91134E-10, A10 = -9.50203E-13
13th page
K = 0.000, A4 = -2.98636E-05, A6 = 6.07607E-08
14th page
K = 0.000, A4 = 1.57106E-05, A6 = 7.51891E-08
18th page
K = 0.000, A4 = 4.34138E-06, A6 = 5.23615E-08
22nd page
K = 0.000, A4 = 7.48893E-05, A6 = -1.77938E-08, A8 = -6.79378E-10, A10 = 4.31753E-12
23rd page
K = 0.000, A4 = 7.96726E-05, A6 = -8.31628E-08, A8 = -6.12256E-10, A10 = 3.70887E-12

Various data 1
Zoom data
WE ST TE
Focal length 12.30 37.80 118.18
FNO. 4.08 5.00 5.77
Angle of view 2ω (°) 90.02 32.22 10.36
Image height 10.82 10.82 10.82

D3 0.80 22.41 40.18
D11 41.22 19.61 1.84
D12 28.08 12.56 1.00
D18 1.81 3.73 11.47
D21 2.50 16.10 19.92

fb (in air) 14.54 14.54 14.54
Total length (in air) 149.25 149.25 149.25

Various data 2
f1 105.59
f2 -19.29
f3 21.25
f4 -16.44
f5 54.38

Numerical Example 7
Surface number r d nd νd
1 40.263 1.29 1.84666 23.78
2 29.746 7.31 1.72916 54.68
3 278.129 D3 (variable)
4 139.796 1.00 1.83481 42.71
5 11.899 7.85
6 -22.609 1.00 1.80400 46.57
7 34.548 4.38 1.74077 27.76
8 -30.972 0.10
9 (Aspherical) 39.907 3.50 1.52542 55.78
10 (Aspherical) 145.451 D10 (variable)
11 (aperture) ∞ D11 (variable)
12 (Aspherical) 17.180 5.13 1.49700 81.54
13 (Aspherical) -72.135 0.10
14 15.472 6.24 1.48749 70.23
15 -23.128 1.00 1.80400 46.57
16 28.796 0.70
17 56.670 1.10 1.80 100 34.97
18 15.718 3.73 1.49700 81.54
19 (Aspherical) -20.851 D19 (variable)
20 131.499 1.97 1.88300 40.76
21 10.251 2.14 1.84666 23.78
22 16.659 D22 (variable)
23 20.439 4.00 1.51633 64.14
24 90.202 13.08
25 ∞ 4.00 1.51633 64.14
26 ∞ 0.80
Image plane ∞

Aspheric coefficient 9th surface
K = 0.000, A4 = 5.76601E-05, A6 = -9.05864E-08, A8 = 5.31964E-09, A10 = -2.59807E-11
10th page
K = 0.000, A4 = 3.74443E-05, A6 = -7.75028E-08, A8 = 6.59071E-09, A10 = -3.83533E-11
12th page
K = 0.000, A4 = 7.48908E-06, A6 = 4.86350E-07, A8 = -7.01907E-09, A10 = 5.98610E-11
13th page
K = 0.000, A4 = 2.45836E-05, A6 = 5.59914E-07, A8 = -1.07754E-08, A10 = 8.59302E-11
19th page
K = 0.000, A4 = 8.78207E-05, A6 = 1.93554E-07, A8 = 9.40918E-09, A10 = -1.77144E-11

Various data 1
Zoom data
WE ST TE
Focal length 14.35 31.00 68.60
FNO. 3.93 4.81 5.75
Angle of view 2ω (°) 79.81 37.66 17.77
Image height 10.82 10.82 10.82

D3 0.81 13.92 21.27
D10 21.65 8.54 1.00
D11 19.40 12.06 1.00
D19 1.80 4.16 9.29
D22 2.37 7.35 13.28

fb (in air) 16.51 16.51 16.51
Full length (in air) 115.07 115.07 115.07

Various data 2
f1 67.83
f2 -17.24
f3 21.53
f4 -21.24
f5 50.20

  9, FIG. 11, FIG. 13, FIG. 15, FIG. 17, FIG. 19 and FIG. 21 are (a) wide angle end (WE), (b) intermediate (ST), (c) in the first to seventh embodiments. It is an aberration diagram at an infinite object point at the telephoto end (TE). 10, 12, 14, 16, 18, 20, and 22 are (a) wide-angle end (WE), (b) intermediate (ST), c) Various aberration diagrams at a close-up shooting distance at the telephoto end (TE).

  10 and 12 are graphs showing various aberrations of the first and second embodiments at a shooting distance of 0.3 m. FIG. 14 is a diagram illustrating various aberrations of Example 3 at a shooting distance of 0.35 m. FIG. 16 is a diagram illustrating various aberrations of the fourth embodiment at a shooting distance of 0.4 m. FIG. 18 is a diagram illustrating various aberrations of Example 5 at a shooting distance of 0.45 m. FIG. 20 is a diagram illustrating all aberrations of the sixth embodiment at a shooting distance of 0.5 m. FIG. 22 is a diagram illustrating various aberrations of Example 7 at a shooting distance of 0.3 m.

  In these various aberration diagrams, SA represents spherical aberration, AS represents astigmatism, DT represents distortion, and CC represents lateral chromatic aberration. The spherical aberration SA is shown for each wavelength of 587.6 nm (d line: solid line), 435.8 nm (g line: broken line), and 656.3 nm (C line: dotted line). The chromatic aberration of magnification CC is shown for each wavelength of 435.8 nm (g line: broken line) and 656.3 nm (C line: dotted line) with respect to the d line. Astigmatism DT, the solid line indicates the sagittal image plane, and the broken line indicates the meridional image plane. FNO indicates the F number, and FIY indicates the maximum image height.

About the said Examples 1-7, the value of each conditional expression (1)-(6) is shown below.

Example 1 Example 2 Example 3 Example 4
Conditional expression (1) -0.170 -0.163 -0.267 -0.173
Conditional expression (2) 0.080 0.094 0.084 0.096
Conditional expression (3) 0.062 0.070 0.064 0.068
Conditional expression (4) 0.418 0.498 0.737 0.415
Conditional expression (5) 0.080 0.090 0.181 0.079
Conditional expression (6) 9.35 9.30 9.63 11.07
Conditional expression (7) 2.08 2.01 1.87 2.61
Conditional expression (A) 10.82 10.82 10.82 10.82

Example 5 Example 6 Example 7
Conditional expression (1) -0.172 -0.156 -0.313
Conditional expression (2) 0.123 0.237 0.059
Conditional expression (3) 0.086 0.139 0.053
Conditional expression (4) 0.430 0.529 0.482
Conditional expression (5) 0.083 0.102 0.127
Conditional expression (6) 11.68 12.45 9.11
Conditional expression (7) 2.64 3.20 1.43
Conditional expression (A) 10.82 10.82 10.82

  FIG. 23 is a cross-sectional view of a single-lens mirrorless camera as an image pickup apparatus using the zoom lens of the present embodiment and using a small CCD or CMOS as an image pickup device. In FIG. 23, 1 is a single-lens mirrorless camera, 2 is an imaging lens system disposed in the lens barrel, 3 is a lens barrel mount that allows the imaging lens system 2 to be attached to and detached from the single-lens mirrorless camera 1, A mount of type or bayonet type is used. In this example, a bayonet type mount is used. Reference numeral 4 denotes an image sensor surface, and 5 denotes a back monitor.

 As the imaging lens system 2 of the single-lens mirrorless camera 1 having such a configuration, for example, the zoom lens of the present embodiment shown in Examples 1 to 7 is used.

  24 and 25 are conceptual diagrams of the configuration of the imaging apparatus according to the present embodiment in which a zoom lens is incorporated in the photographing optical system 41. FIG. FIG. 24 is a front perspective view showing the appearance of a digital camera 40 as an image pickup apparatus, and FIG. 25 is a rear perspective view of the same.

  The digital camera 40 of this embodiment includes a photographing optical system 41 positioned on the photographing optical path 42, a shutter button 45, a liquid crystal display monitor 47, and the like. When the shutter button 45 disposed on the top of the digital camera 40 is pressed, In conjunction with this, photographing is performed through the photographing optical system 41, for example, the zoom lens of the first embodiment. An object image formed by the photographing optical system 41 is formed on an image sensor (photoelectric conversion surface) provided in the vicinity of the imaging surface. The object image received by the image sensor is displayed on the liquid crystal display monitor 47 provided on the back of the camera as an electronic image by the processing means. In addition, the photographed electronic image can be recorded in a recording unit.

  FIG. 26 is a block diagram showing an internal circuit of a main part of the digital camera 40 of the present embodiment. In the following description, the processing unit 51 described above is configured by, for example, the CDS / ADC unit 24, the temporary storage memory 17, the image processing unit 18, and the like, and the storage unit 52 is configured by a storage medium unit or the like.

  As shown in FIG. 26, the digital camera 40 is connected to the operation unit 12, the control unit 13 connected to the operation unit 12, and the control signal output port of the control unit 13 via buses 14 and 15. The imaging drive circuit 16, the temporary storage memory 17, the image processing unit 18, the storage medium unit 19, the display unit 20, and the setting information storage memory unit 21 are provided.

  The temporary storage memory 17, the image processing unit 18, the storage medium unit 19, the display unit 20, and the setting information storage memory unit 21 can mutually input and output data via the bus 22. In addition, a CCD 49 and a CDS / ADC unit 24 are connected to the imaging drive circuit 16.

  The operation unit 12 includes various input buttons and switches, and notifies the control unit of event information input from the outside (camera user) via these buttons. The control unit 13 is a central processing unit composed of, for example, a CPU, and has a built-in program memory (not shown) and controls the entire digital camera 40 according to a program stored in the program memory.

  The CCD 49 is an image pickup device that is driven and controlled by the image pickup drive circuit 16, converts the light amount of each pixel of the object image formed via the image pickup optical system 41 into an electric signal, and outputs the electric signal to the CDS / ADC unit 24.

The CDS / ADC unit 24 amplifies the electric signal input from the CCD 49, performs analog / digital conversion, and performs raw video data (Bayer data, hereinafter referred to as RAW data) obtained by performing the amplification and digital conversion. ) To the temporary memory 17.
The temporary storage memory 17 is a buffer made of, for example, SDRAM, and is a memory device that temporarily stores RAW data output from the CDS / ADC unit 24. The image processing unit 18 reads out the RAW data stored in the temporary storage memory 17 or the RAW data stored in the storage medium unit 19, and includes distortion correction based on the image quality parameter designated by the control unit 13. It is a circuit that performs various image processing electrically.

  The storage medium unit 19 is detachably mounted with a card-type or stick-type storage medium made of, for example, a flash memory, and the RAW data transferred from the temporary storage memory 17 and the image processing unit 18 to these flash memories. Image-processed image data is recorded and held.

  The display unit 20 includes a liquid crystal display monitor 47 and the like, and displays captured RAW data, image data, an operation menu, and the like. The setting information storage memory unit 21 includes a ROM unit that stores various image quality parameters in advance, and a RAM unit that stores image quality parameters read from the ROM unit by an input operation of the operation unit 12.

  By adopting the zoom lens of the present invention as the imaging optical system 41, the digital camera 40 configured in this way can be a small imaging device suitable for moving image imaging.

  Although various embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and embodiments configured by appropriately combining the configurations of the respective embodiments also fall within the scope of the present invention. Is.

DESCRIPTION OF SYMBOLS 1 ... Lens interchangeable camera 2 ... Imaging lens system 3 ... Mount part 4 ... Image pick-up element surface 5 ... Back monitor 12 ... Operation part 13 ... Control part 14, 15 ... Bus 16 ... Imaging drive circuit 17 ... Temporary memory 18 ... Image Processing unit 19 ... Storage medium unit 20 ... Display unit 21 ... Setting information storage memory unit 22 ... Bus 24 ... CDS / ADC unit 40 ... Digital camera 41 ... Shooting optical system 42 ... Shooting optical path 45 ... Shutter button 47 ... Liquid crystal display monitor

Claims (22)

From the object side to the image side,
A first lens unit having positive refractive power;
A second lens unit having negative refractive power;
An aperture stop,
A third lens unit having positive refractive power;
A fourth lens unit having negative refractive power;
A fifth lens unit having positive refractive power;
Have
When zooming from the wide-angle end to the telephoto end,
At least the positions of the first lens group and the aperture stop are fixed,
The second lens group and the third lens group move in the optical axis direction;
The distance between each lens group and the aperture stop changes,
When focusing from infinity focus state to close focus state,
The fourth lens group moves in the optical axis direction;
A zoom lens satisfying the following conditional expression (1):
−0.36 <f4 / f1 <−0.05 (1)
However,
f1 is the focal length of the first lens group,
f4 is a focal length of the fourth lens group,
It is. At the time of zooming from the wide angle end to the telephoto end, at least the positions of the first lens group, the aperture stop, and the fifth lens group are fixed,
2. The zoom lens according to claim 1, wherein the second lens group, the third lens group, and the fourth lens group move in an optical axis direction. The zoom lens according to claim 1, wherein the following conditional expression (1-1) is satisfied.
−0.33 <f4 / f1 <−0.10 (1-1) 4. The zoom lens according to claim 1, wherein the following conditional expressions (2) and (3) are satisfied at a wide-angle end and at infinity in-focus state.
| Y1′−y1 | / Δs <0.35 (2)
| Y0.7′−y0.7 | / Δs <0.35 (3)
However,
y1 is the maximum image height on the imaging surface,
y0.7 is 0.7 times the maximum image height y1,
y1 ′ is an image where the fourth lens group is moved with respect to an object at infinity, and a defocus amount of Δs is generated from focusing on infinity, and the image height reaches y1 at focusing on infinity. A ray height at a position where a principal ray having the same angle of view as the angle of view intersects the imaging surface,
y0.7 ′ is the image of y0.7 at the time of focusing on infinity when the fourth lens group is moved with respect to an object at infinity and a defocus amount of Δs is generated from the time of focusing on infinity. A ray height at a position where the principal ray having the same angle of view as the shooting angle of view that reaches the height intersects the imaging surface;
Δs is 8 * maximum image height y1 / 1000,
And
The units of y1, y0.7, y1 ', y0.7', and Δs are all mm.
It is. The zoom lens according to claim 4, wherein the maximum image height y1 of the imaging surface satisfies the following conditional expression (A).
8.0 <y1 <25.0 (A) 6. The zoom lens according to claim 4, wherein the following conditional expressions (2-1) and (3-1) are satisfied in an infinitely focused state at the wide-angle end.
| Y1′−y1 | / Δs <0.29 (2-1)
| Y0.7′−y0.7 | / Δs <0.29 (3-1) 7. The zoom lens according to claim 1, wherein the fourth lens group performs a wobbling movement in an optical axis direction before the focusing. 8. The fourth lens group includes:
Having one positive lens and one negative lens,
The zoom lens according to claim 1, wherein the total number of lenses in the fourth lens group is two. The zoom lens according to any one of claims 1 to 8, wherein the following conditional expression (4) is satisfied.
0.20 <Σ1G / Σ2G <1.00 (4)
However,
Σ1G is the thickness of the first lens group on the optical axis,
Σ2G is the thickness of the second lens group on the optical axis,
It is. The zoom lens according to claim 9, wherein the following conditional expression (4-1) is satisfied.
0.31 <Σ1G / Σ2G <0.87 (4-1) The zoom lens according to any one of claims 1 to 10, wherein the following conditional expression (5) is satisfied.
0.03 <Σ1G / f1 <0.23 (5)
However,
Σ1G is the thickness of the first lens group on the optical axis,
f1 is the focal length of the first lens group,
It is. The zoom lens according to claim 11, wherein the following conditional expression (5-1) is satisfied.
0.05 <Σ1G / f1 <0.21 (5-1) The zoom lens according to any one of claims 1 to 12, wherein the following conditional expression (6) is satisfied.
Σ1G5G / y1 <15.9 (6)
However,
Σ1G5G is the thickness on the optical axis from the object side surface of the first lens group to the image side surface of the fifth lens group at the wide-angle end,
y1 is the maximum image height on the imaging surface,
It is. The zoom lens according to claim 12, wherein the following conditional expression (6-1) is satisfied.
Σ1G5G / y1 <14.1 (6-1) The zoom lens according to any one of claims 1 to 14, wherein the following conditional expression (7) is satisfied.
0.50 <d2G / fw <5.00 (7)
However,
d2G is the amount of movement of the second lens group during zooming from the wide-angle end to the telephoto end,
The movement toward the image side is a positive sign,
fw is the focal length of the entire zoom lens system at the wide-angle end,
It is. The zoom lens according to claim 15, wherein the following conditional expression (7-1) is satisfied.
0.97 <dG2 / fw <4.10 (7-1) The second lens group, in order from the object side to the image side,
It consists of four lenses, a first negative lens, a second negative lens, a first positive lens, and a second positive lens.
Or
17. The lens according to claim 1, comprising four lenses: a first negative lens, a second negative lens, a first positive lens, and a third negative lens. Zoom lens described in 1. The third lens group, in order from the object side to the image side,
It consists of four lenses, a first positive lens, a second positive lens, a first negative lens, and a third positive lens.
Or
It consists of five lenses: a first positive lens, a second positive lens, a first negative lens, a second negative lens, and a third positive lens,
18. The zoom lens according to claim 1, wherein at least two lenses in the third lens group are cemented with each other. The fifth lens group includes:
Consisting of one positive lens,
Or
The zoom lens according to any one of claims 1 to 18, comprising two lenses, one positive lens and one negative lens. At the telephoto end against the wide angle end
The second lens group is located on the image side;
The third lens group is located on the object side;
The fourth lens group is located on the object side;
The distance between the third lens group and the fourth lens group is widened,
The zoom lens according to any one of claims 1 to 19, wherein an interval between the fourth lens group and the fifth lens group is widened. 21. The zoom lens according to claim 1, wherein the following conditional expressions (8) and (9) are satisfied.
4.6 <ft / fw <12.5 (8)
35 ° <ωw <50 ° (9)
However,
fw is the focal length of the entire zoom lens system when focusing at infinity at the wide angle end,
ft is the focal length of the entire zoom lens at the telephoto end at infinity,
ωw is the maximum half angle of view when focusing at infinity at the wide angle end,
It is. A zoom lens according to any one of claims 1 to 21,
An imaging device having an imaging surface for converting an optical image into an electrical signal;
An imaging apparatus comprising:

Images