JP2020012908A - Zoom lens and image capturing device - Google Patents

Abstract

To provide a zoom lens which is advantageous in providing a wide view angle, a high zoom ratio, and reduced magnification chromatic aberration at a wide-angle end.SOLUTION: A zoom lens provided herein comprises a first lens group L1 with positive refractive power, a second lens group L2 with negative refractive power configured to move for zooming, at least one lens group L3, L4 configured to move for zooming, and a final lens group L5 with positive refractive power in order from the object side to the image side, and is configured such that a distance between each pair of adjacent lens groups changes for zooming. The final lens group includes a positive lens. An Abbe number and partial dispersion ratio of the positive lens, a distance from an aperture stop to an apex of an object-side surface of the positive lens along an optical axis when focused at infinity at the wide-angle end, and a distance from the aperture stop to an apex of the most image-side surface of the final lens group when focused at infinity at the wide-angle end satisfy predefined conditional expressions.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a zoom lens and an imaging device.

  For example, in order to enhance the functionality of an imaging device (camera) including an imaging device, such as a still camera, a video camera, a television camera, a cinema camera, and a monitoring camera, a zoom lens used therein has a high zoom ratio, a large aperture ratio, and What has high optical performance is demanded. In particular, imaging devices such as CCD and CMOS devices used in professional use television cameras and movie cameras have excellent uniformity of resolution over the entire imaging range. Therefore, the zoom lens is required to have uniform resolving power on the image plane and small chromatic aberration.

  Patent Literature 1 discloses a so-called positive lead type that includes, in order from the object side to the image side, a lens group having a positive refractive power, a lens group having a negative refractive power, and a rear group including at least one lens group. A zoom lens is disclosed.

  Further, Patent Document 2 includes, in order from the object side to the image side, first to fifth lens groups having positive, negative, positive, negative, and positive refractive powers, respectively, and sets an interval between each pair of adjacent lens groups. A zoom lens that performs variable magnification (zooming) is disclosed. A positive lead type zoom lens in which the first lens group has a positive refractive power is more advantageous in increasing the zoom ratio than a so-called negative lead type zoom lens in which the first lens group has a negative refractive power.

JP 2015-176118 A JP 2011-123337 A

  In order to obtain high optical performance in a zoom lens having a high zoom ratio, it is important to correct (reduce) fluctuation of chromatic aberration due to zooming, and particularly to correct chromatic aberration of magnification at the wide-angle end. If the refractive power of each lens group is increased while the number of lenses is small, various aberrations occur greatly, and it is difficult to obtain high optical performance. Therefore, it is also difficult to correct lateral chromatic aberration at the wide-angle end.

  In order to correct the secondary spectrum, which is particularly problematic due to lateral chromatic aberration at the wide-angle end, a material having anomalous dispersion is used for a lens having a positive refractive power on the image plane side of the aperture stop (hereinafter also referred to as a positive lens). It is effective to use. Regardless of the zoom state, the axial ray also passes through the high position of the positive lens, so that the axial chromatic aberration is also corrected over the entire zoom range. Therefore, for the positive lens, it is necessary to select the Abbe number and the anomalous dispersion characteristic of the optical material. In order to obtain high optical performance over the entire zoom range while reducing (correcting) the lateral chromatic aberration at the wide-angle end where the zoom lens is conspicuous, especially in the relay lens group that is immovable or fine for zooming, The balance of chromatic aberration correction is important.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a zoom lens that is advantageous for, for example, wide angle of view, high zoom ratio, and reduction of lateral chromatic aberration at the wide angle end.

In order to achieve the above object, in order from the object side to the image side, a first lens unit having a positive refractive power, a second lens unit having a negative refractive power that moves for zooming, and A lens group having at least one moving lens group and a final lens group having a positive refractive power, wherein each pair of adjacent lens groups is changed in distance for zooming; Where the Abbe number and the partial dispersion ratio of the positive lens are νd and θgF, respectively, and the conditional expression θgF − (− 1.6650 × 10 ⁻⁷ νd ³ + 5.2130 × 10 ⁻⁵ νd ² −5.6560) × 10 ⁻³ · νd + 0.7370)> 0,
0.5450 <θgF, and 50.0 <νd <85.0
Satisfied
The distance on the optical axis from the stop at infinity focus and the wide-angle end to the vertex of the object-side surface of the positive lens is Dx, and the focus at infinity and the widest end at the wide-angle end is the most image side of the last lens group from the stop. 0.50 <Dx / DR <1.00, where DR is the distance on the optical axis to the vertex of the surface
Satisfy
A zoom lens characterized in that: Here, the Abbe number νd and the partial dispersion ratio θgF are the materials of the g-line (wavelength 435.8 nm), F-line (486.1 nm), C-line (656.3 nm) and d-line (587.6 nm), respectively. Assuming that the refractive indices are Ng, NF, NC, and Nd, respectively, the expressions νd = (Nd−1) / (NF−NC), and θgF = (Ng−NF) / (NF−NC)
It is represented by

  According to the present invention, for example, it is possible to provide a zoom lens that is advantageous for reducing the chromatic aberration of magnification at a wide angle of view, a high zoom ratio, and a wide angle end.

FIG. 3 is a lens cross-sectional view at a wide angle end according to the first exemplary embodiment. FIG. 4A is an aberration diagram of the zoom lens according to the first exemplary embodiment at the wide-angle end, at the middle zoom position, and at the telephoto end, when focused on infinity. FIG. 10 is a sectional view of a zoom lens according to a second embodiment at a wide-angle end when focused on infinity. FIG. 8A is an aberration diagram of the zoom lens according to the second embodiment at the wide-angle end, at the middle zoom position, and at the telephoto end, when focused on infinity. FIG. 10 is a sectional view of a zoom lens according to a third embodiment at a wide-angle end when focused on infinity. FIG. 10A is an aberration diagram of the zoom lens according to the third embodiment when focused on infinity at (A) a wide-angle end, (B) an intermediate zoom position, and (C) a telephoto end. FIG. 10 is a sectional view of a zoom lens according to a fourth embodiment at a wide-angle end when focused on infinity. FIG. 9A is an aberration diagram at the wide-angle end, (B) an intermediate zoom position, and (C) a telephoto end of the zoom lens according to the fourth embodiment when focused on infinity. FIG. 13 is a sectional view of a zoom lens according to a fifth embodiment at a wide-angle end when focused on infinity. FIG. 14A is an aberration diagram of the zoom lens according to the fifth embodiment at the wide-angle end, in the middle zoom position, and at the telephoto end, when focused on infinity. FIG. 13 is a sectional view of a zoom lens according to a sixth embodiment at a wide-angle end when focused on infinity. FIG. 14A is an aberration diagram of the zoom lens according to the sixth embodiment when focused on infinity at (A) a wide-angle end, (B) an intermediate zoom position, and (C) a telephoto end. FIG. 14 is a sectional view of a zoom lens according to a seventh embodiment at a wide-angle end when focused on infinity. FIG. 14A is an aberration diagram of the zoom lens according to the seventh embodiment when focused on infinity at (A) a wide-angle end, (B) an intermediate zoom position, and (C) a telephoto end. FIG. 14 is a lens cross-sectional view of the zoom lens at a wide-angle end when focused on infinity according to an eighth embodiment. FIG. 14A is an aberration diagram of the zoom lens according to the eighth embodiment when focused on infinity at (A) a wide-angle end, (B) an intermediate zoom position, and (C) a telephoto end. FIG. 15 is a sectional view of a zoom lens according to a ninth embodiment at a wide-angle end when focused on infinity. FIG. 15A is an aberration diagram of the zoom lens according to the ninth embodiment when focused on infinity at (A) a wide-angle end, (B) an intermediate zoom position, and (C) a telephoto end. FIG. 21 is a sectional view of a zoom lens according to a tenth embodiment at a wide-angle end when focused on infinity. FIG. 14A is an aberration diagram at a wide-angle end, (B) an intermediate zoom position, and (C) a telephoto end of the zoom lens according to the tenth embodiment when focused on infinity. FIG. 21 is a sectional view of a zoom lens according to an eleventh embodiment at a wide-angle end when focused on infinity. FIG. 32 is an aberration diagram at the time of focusing on infinity at the (A) wide-angle end, (B) an intermediate zoom position, and (C) a telephoto end of the zoom lens according to the eleventh embodiment. FIG. 23 is a sectional view of a zoom lens according to a twelfth embodiment at a wide-angle end when focused on infinity. FIG. 32 is an aberration diagram at the time of focusing on infinity of the zoom lens according to the twelfth embodiment at (A) a wide-angle end, (B) an intermediate zoom position, and (C) at a telephoto end. FIG. 7 is a θgF-νd diagram. FIG. 34 is a schematic diagram of main parts of an imaging device according to a thirteenth embodiment.

  Next, embodiments of the zoom lens according to the present invention will be described. The zoom lens of each embodiment includes a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a rear lens group including at least one lens group, which are arranged in order from the object side to the image side. In zooming, each set of lens groups adjacent to each other changes the interval for zooming.

The first lens group has at least one positive lens. The material of at least one glass positive lens Gp included in the first lens group has a refractive index of the material of nd, an Abbe number of the material of νd, and a material of the material. Let the partial dispersion ratio be θgF. The positive lens Gp is a distance Dx on the optical axis at the wide-angle end at infinity focusing from the stop to the vertex on the object side surface of the positive lens in the last lens group, and the most image in the last lens group from the stop. The distance on the optical axis at the wide-angle end at the time of infinite focusing to the vertex of the lens surface on the side is DR. At this time,
θgF − (− 1.6650 × 10 ⁻⁷ × νd ³ + 5.2130 × 10 ⁻⁵ × νd ² −5.6560 × 10 ⁻³ × νd + 0.7370)> 0 (1)
0.5450 <θgF (2)
50.0 <νd <85.0 (3)
0.50 <Dx / DR <1.00 (4)
The following conditional expression is satisfied.

Here, the Abbe number νd and the partial dispersion ratio θgF of the material of the glass optical element (lens) used in this embodiment are as follows. The refractive indices for the g line (wavelength 435.8 nm), the F line (486.1 nm), the C line (656.3 nm), and the d line (587.6 nm) of the Fraunhofer line are represented by Ng, NF, NC, and Nd, respectively. As
νd = (Nd-1) / (NF-NC)
θgF = (Ng−NF) / (NF−NC)
It is represented by the following formula.

  The zoom lens of each embodiment is a positive lead type zoom lens in which a first lens group having a positive refractive power and a second lens group having a negative refractive power that moves during zooming are arranged. The first lens group having a positive refractive power has a first sub lens group having a negative refractive power, a second sub lens group having a positive refractive power, and a positive refractive power in order from the object side to the image side. It may have a sub-unit configuration like the third sub-lens group. With the above-described configuration, it is possible to obtain the first lens group that is particularly excellent in suppressing a variation in aberration due to focusing at a wide angle of view. The first lens group having a positive refractive power includes, in order from the object side to the image side, subunits such as a first sub lens group having a negative refractive power and a second sub lens group having a positive refractive power. It may have a configuration. The second lens group having a negative refractive power moves to the image side when zooming from the wide-angle end to the telephoto end, and employs a zoom type that easily achieves a high zoom ratio.

  In the zoom lens of the present invention, the stop is disposed on the object side of the final lens group. In order to determine the maximum axial beam diameter at the wide-angle end, it is preferable to dispose the stop on the image side of the second lens unit and on the object side of the final lens unit. A subject image formed by the zoom lens of the present invention is formed into an image by an image pickup device (photoelectric conversion device) such as a CCD sensor or a CMOS sensor. The last lens group has a positive refractive power, so that it is easy to maintain good telecentricity on the image side. The final lens group may assume a subunit configuration as described later. An object-side sub-lens group having a negative refractive power that receives a convergent light beam from the lens group on the object side of the last lens group and emits the light as a divergent light beam may be provided. Further, a part of the subunit group included in the final lens group may move during zooming or focusing. Further, a focal length conversion optical system for converting the focal length of the entire lens system by inserting and removing different lens groups in the optical path may be provided. Further, an image-side sub-lens group having a positive refractive power that guides a light beam to an image and is arranged on the image side of the conversion optical system may be provided. When the final lens group is configured as described above, it is possible to respond to a demand for a further longer focal length simply by inserting and removing a part of the lens configuration of the lens group.

  Here, the relationship between the partial dispersion ratio of the material used for the positive lens Gp of the final lens group and the color yield of magnification will be described. As shown in FIG. 21, the existing optical materials are distributed in a range where the partial dispersion ratio θgF is narrow with respect to the Abbe number νd, and the smaller the νd, the larger the θgF. Correcting chromatic aberration for a specific two wavelengths is generally referred to as two-wavelength achromatism (primary spectrum correction). In particular, in a high-magnification zoom lens, the axial chromatic aberration and the chromatic aberration of magnification of each lens unit are corrected so as to be approximately zero in order to suppress the chromatic aberration variation due to zooming. Correcting chromatic aberration for three specific wavelengths by further adding specific wavelengths is generally referred to as secondary spectrum correction. With the demand for higher specifications of the zoom lens, it becomes more difficult to reduce the secondary spectrum of the chromatic aberration of magnification at the wide-angle end as the zoom ratio of a higher magnification is achieved.

  The conditional expressions (1) and (2) define the partial dispersion ratio θgF of the material of the positive lens Gp in the final lens group. By satisfying conditional expressions (1) and (2), it becomes possible to correct chromatic aberration of magnification, which tends to increase to overbalance at the wide-angle end of the zoom lens, to an appropriate balance. If the value is smaller than the lower limit of conditional expression (1), the secondary spectrum of axial chromatic aberration increases at the telephoto end, which is not preferable. In FIG. 25, the solid line indicates the curve of the conditional expression (1).

  Conditional expression (3) defines the Abbe number νd of the material of the positive lens Gp in the final lens group. If the Abbe number νd increases beyond the upper limit value of the conditional expression (3), the refractive index generally decreases, the required lens thickness increases, and the size increases, which is not preferable. If the Abbe number νd is smaller than the lower limit of conditional expression (3), it becomes difficult to satisfactorily correct lateral chromatic aberration on the wide-angle side and axial chromatic aberration on the telephoto side.

  Conditional expression (4) regulates the arrangement of the positive lens Gp in the last lens group. The distance on the optical axis at the wide-angle end at the time of infinity focusing from the vertex on the object side of the positive lens Gp included in the final lens group to the stop is Dx, and the infinity from the vertex of the lens surface closest to the image side of the final lens group to the stop. Let DR be the distance on the optical axis at the wide-angle end during focusing. In order to reduce the secondary spectrum of the chromatic aberration of magnification, it is effective to arrange the positive lens Gp at a position where the incident height of the off-axis pupil paraxial ray is high. Generally, as the distance from the stop increases, the incident height of the off-axis pupil paraxial ray tends to increase. By satisfying the expression (4), the secondary spectrum of the chromatic aberration of magnification at the wide-angle end is further improved. Can be corrected. If the lower limit of the condition (4) is not satisfied, it is difficult to correct the secondary spectrum of the lateral chromatic aberration at the wide-angle end, which is not preferable. If the condition of the upper limit of the expression (4) is not satisfied, the positive lens Gp does not have an appropriate lens thickness, and the effect of correcting lateral chromatic aberration cannot be sufficiently exhibited.

In each embodiment, it is preferable that the numerical ranges of the conditional expressions (1) to (4) are set as follows.
θgF − (− 1.6650 × 10 ⁻⁷ · νd ³ + 5.2130 × 10 ⁻⁵ · νd ² −5.6560 × 10 ⁻³ · νd + 0.7398)> 0 (1a)
0.5490 <θgF (2a)
52.0 <νd <81.0 (3a)
0.53 <Dx / DR <0.97 (4a)

It is more preferable to set the numerical ranges of the conditional expressions (1a) to (3a) as follows.
θgF − (− 1.6650 × 10 ⁻⁷ · νd ³ + 5.2130 × 10 ⁻⁵・ νd ² −5.6560 × 10 ⁻³・ νd + 0.7398)> 0 (1b)
0.5543 <θgF (2b)
54.0 <νd <67.0 (3b)
0.55 <Dx / DR <0.95 (4b)
In each embodiment, a zoom lens having a wide angle of view, a high zoom ratio, and high optical performance is obtained with the above-described configuration.

At this time, it is preferable to satisfy at least one of the following conditional expressions.
0.50 <fp / fR <2.50 (5)
-2.0 <(R1 + R2) / (R1-R2) <1.5 (6)
0.50 <α <5.00 (7)
1.550 <nd <1.750 (8)
1.00 <fR / fW <20.00 (9)

  Conditional expression (5) defines the ratio of the focal length of the positive lens Gp to the focal length of the final lens group. The focal length of the positive lens Gp included in the final lens group is fp, and the focal length of the final lens group is fR. By satisfying the expression (5), the positive lens Gp can be given an appropriate power, and the secondary spectrum of the chromatic aberration of magnification can be corrected well. If the condition of the upper limit of the expression (5) is not satisfied, the positive lens Gp cannot have appropriate power, and the secondary spectrum correction of the chromatic aberration of magnification cannot be sufficiently performed. If the lower limit of the expression (5) is not satisfied, the power of the positive lens Gp having high anomalous dispersion becomes too strong, which causes overcorrection of chromatic aberration of magnification at the wide-angle end and deterioration of chromatic aberration correction balance of magnification over the entire zoom range. It also becomes difficult to avoid overcorrection of axial chromatic aberration.

  Conditional expression (6) defines the lens shape of the positive lens Gp in the last lens group. The radius of curvature of the positive lens Gp on the object side and the radius of curvature on the image side are R1 and R2, respectively. When the value exceeds the upper limit of conditional expression (6), the absolute value of the radius of curvature of the positive lens Gp on the object side becomes small, so that various aberrations generated on the object side surface become too large. And the optical performance deteriorates. If the lower limit of conditional expression (6) is exceeded, the absolute value of the image-side radius of curvature of the positive lens Gp becomes small, so that various aberrations occurring on the image-side surface become too large. And the optical performance deteriorates. Alternatively, both surfaces of the object side and the image side approach the flat plate, and have no power.

Conditional expression (7) defines the linear expansion coefficient of the extraordinary dispersion material of the positive lens Gp in the last lens group. The coefficient of linear expansion α represents an average coefficient of linear expansion (10 ⁻⁵ / K) in a range from −30 ° C. to + 70 ° C. If the coefficient of linear expansion increases beyond the upper limit of conditional expression (7), the change in lens shape due to a change in temperature increases, and the optical performance deteriorates. If the coefficient of linear expansion is smaller than the lower limit of conditional expression (7), the change in lens shape due to temperature change is small, but it is difficult to produce a material satisfying conditional expression.

  The refractive index nd of the material of the positive lens Gp in the last lens unit L in the conditional expression (8) is defined. If the refractive index exceeds the upper limit of conditional expression (8) and the refractive index is increased, it is easy to reduce the size of the entire system, but it is difficult to produce a material satisfying conditional expressions (1) and (2). On the other hand, if the refractive index is lower than the lower limit of conditional expression (8), the lens thickness is increased, and the entire system is undesirably enlarged.

  Conditional expression (9) defines the ratio of the focal length of the entire system at the wide-angle end of the zoom lens to the focal length of the final lens group. The focal length of the entire system (entire) at the wide-angle end of the zoom lens is fW. If the condition of the upper limit of the equation (9) is not satisfied, the final lens cannot have appropriate power, and chromatic aberration cannot be sufficiently corrected. If the lower limit of the expression (9) is not satisfied, the power of the refracting power of the final lens becomes too strong, resulting in overcorrection of chromatic aberration at the wide-angle end and deterioration of chromatic aberration correction balance over the entire zoom range.

In each embodiment, it is preferable that the numerical ranges of the conditional expressions (5) to (9) are set as follows.
0.55 <fp / fR <2.40 (5a)
-1.5 <(R1 + R2) / (R1-R2) <1.0 (6a)
0.80 <α <3.00 (7a)
1.550 <nd <1.700 (8a)
1.50 <fR / fW <17.00 (9a)

More preferably, the numerical ranges of the conditional expressions (5a) to (9a) are set as follows.
0.60 <fp / fR <2.30 (5b)
-1.3 <(R1 + R2) / (R1-R2) <0.8 (6b)
0.90 <α <1.60 (7b)
1.550 <nd <1.650 (8b)
2.00 <fR / fW <15.00 (9b)

In each embodiment, by configuring each element as described above, it is possible to obtain a compact, high-spec zoom lens having a wide angle and a high zoom ratio and high performance.
Hereinafter, embodiments of the zoom lens of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a sectional view of a zoom lens according to a first embodiment at a wide-angle end. Example 1 is a zoom lens having a zoom ratio of 17.00 and an aperture ratio of about 1.91 to 2.52.

  In the lens cross-sectional view, the left is the object side (front) and the right is the image side (rear). If i is the order of the lens groups from the object side, Li indicates the i-th lens group. G is an optical block such as a prism or an optical filter. SP is an aperture stop, and IP is an image plane. The image plane IP corresponds to an imaging plane of an imaging element (photoelectric conversion element) such as a CCD sensor or a CMOS sensor when a zoom lens is used as an imaging optical system of a digital camera, a video camera, or a surveillance camera. The same applies to Examples 2 to 12 to be described later.

  The zoom lens according to the first embodiment includes the following lens groups arranged in order from the object side to the image side. A first lens unit L1 having a positive refractive power, a second lens unit L2 having a negative refractive power, a third lens unit L3 having a negative refractive power, a fourth lens unit L4 having a positive refractive power, an aperture stop SP, The fifth lens unit L5 having a refractive power includes five lens units. During zooming, the first lens unit L1, the fifth lens unit L5, and the aperture stop SP do not move. During zooming from the wide-angle end to the telephoto end, the second lens group moves toward the image side, the third lens group moves along a locus convex toward the object side, and the fourth lens group moves along a locus convex toward the object side. . The first lens unit L1 includes, in order from the object side to the image side, a first sub lens unit L1a having a fixed negative refractive power during focusing, and a second sub lens unit having a positive refractive power moving on the optical axis during focusing. L1b. When focusing is performed, an inner focus method is employed in which the second sub lens unit L1b of the first lens unit L1 is moved on the optical axis to perform focusing. When focusing from infinity to a short distance, the second sub-lens group L1b moves on the optical axis to the object side.

  In the zoom lens according to the present embodiment, the number of lenses in the first lens unit L1 is preferably configured as follows. This is the same for the embodiment described later.

  When miniaturization is realized in a zoom lens having a zoom ratio exceeding 80, the first lens unit L1 is configured to move from the wide-angle end to the telephoto end toward the object side, and the first lens unit L1 includes four or more lenses. Preferably. When the lens system is of a wide-angle type, the lens outer diameter of the first lens unit L1 is determined by an off-axis ray. For this reason, the smaller the number of constituent lenses of the first lens unit L1, the more advantageous for miniaturization. However, in order to increase the magnification, if the number of constituent lenses of the first lens unit L1 is too small, spherical aberration, coma, It is difficult to correct both axial chromatic aberrations. Therefore, by reducing the overall length of the wide-angle lens, which determines the outer diameter of the first lens unit L1, the height of off-axis rays in the front lens is reduced, and even if the number of lenses of the first lens unit L1 is increased, the size is large. It is preferable to adopt a configuration that does not affect the above. In particular, it is preferable that the first lens group includes, from the object side, a negative lens and a plurality of positive lenses.

  Also, in a zoom lens having a zoom ratio of about 20 to 60, the first lens group should be composed of a negative lens and a plurality of positive lenses from the object side in order to correct spherical aberration, coma, and axial chromatic aberration together. Is preferred.

  In a zoom lens having a zoom ratio of 10 or less, it is preferable that the first lens unit L1 includes three negative lenses, a positive lens, and a positive lens, or two negative lenses and a positive lens. It is desirable that the second lens unit L2 includes at least two negative lenses and one positive lens.

  By making the second lens unit L2 that moves during zooming a lens unit configuration that precedes the negative lens, it is possible to cope with a wide angle. It is desirable that the lens group adjacent to the image side of the aperture stop SP has a positive refractive power. At the wide-angle end, the on-axis luminous flux becomes a divergent luminous flux when passing through the second lens unit L2 having a negative refractive power. However, the on-axis luminous flux passes through the lens unit R adjacent to the image side of the aperture stop SP following the image side of the second lens unit L2. Positive refractive power. As a result, a converging effect can be imparted to the light beam, and the effective lens diameter of the rear group can be reduced.

  2A, 2B, and 2C show aberration diagrams at the wide-angle end, an intermediate zoom position, and a telephoto end when focusing on infinity according to the first embodiment. In the diagram showing the spherical aberration in the longitudinal aberration diagram, the solid line d is the d line (wavelength 587.6 nm), the two-dot chain line g is the g line (wavelength 435.8 nm), and the one-dot chain line C is the C line (wavelength 656.nm). 3 nm). In the figures showing astigmatism, S in the solid line indicates the sagittal direction of the d-line, and M in the broken line indicates the meridional direction of the d-line. Further, the aberration diagram showing the distortion shows the distortion at the d-line. The chromatic aberration of magnification is shown for the g-line with respect to the d-line. Fno is an F-number, and ω is a half angle of view (degree) of the shooting angle of view. The same applies to Examples 2 to 12 to be described later.

  The zoom lens according to the present embodiment is used as an imaging optical system of an imaging device such as a video camera, a digital still camera, a television camera, a cinema camera, and a monitoring camera.

  FIG. 3 is a lens cross-sectional view at the wide-angle end according to the second embodiment. Example 2 is a zoom lens having a magnification ratio of 17.00 and an aperture ratio of about 1.91 to 2.52.

  The schematic configuration of the zoom lens according to the second embodiment, and the movement of the lens group for zooming and focusing are the same as those of the first embodiment, and a description thereof will be omitted.

  4A, 4B, and 4C are aberration diagrams at the wide-angle end, an intermediate zoom position, and a telephoto end when focusing on infinity according to the second embodiment.

  FIG. 5 is a lens sectional view at the wide-angle end according to the third embodiment. Embodiment 3 is a zoom lens having a magnification ratio of 17.00 and an aperture ratio of about 1.91 to 2.51.

  The schematic configuration of the zoom lens according to the third embodiment, and the movement of the lens groups for zooming and focusing are the same as those of the first embodiment, and a description thereof will be omitted.

  6A, 6B, and 6C are aberration diagrams at the wide-angle end, an intermediate zoom position, and a telephoto end when focusing on infinity according to the third embodiment.

  FIG. 7 is a lens cross-sectional view at the wide angle end according to the fourth embodiment. Example 4 is a zoom lens having a magnification ratio of 17.00 and an aperture ratio of about 1.91 to 2.52.

  The schematic configuration of the zoom lens according to the fourth embodiment, and the movement of the lens groups for zooming and focusing are the same as those of the first embodiment, and a description thereof will be omitted.

  FIGS. 8A, 8B, and 8C are aberration diagrams at the wide-angle end, an intermediate zoom position, and a telephoto end when focusing on infinity according to the fourth embodiment.

  FIG. 9 is a lens cross-sectional view at a wide angle end according to a fifth embodiment. Example 5 is a zoom lens having a zoom ratio of 17.00 and an aperture ratio of about 1.91 to 2.52.

  The schematic configuration of the zoom lens according to the fifth embodiment, and the movement of the lens groups for zooming and focusing are the same as those of the first embodiment, and a description thereof will be omitted.

  10A, 10B, and 10C are aberration diagrams at the wide-angle end, an intermediate zoom position, and a telephoto end when focusing on infinity according to the fifth embodiment.

  FIG. 11 is a sectional view of a lens at a wide angle end according to a sixth embodiment. Example 6 is a zoom lens having a magnification ratio of 8.00 times and an aperture ratio of about 2.80 to 3.62.

  The zoom lens according to the sixth embodiment performs main zooming by moving the second lens unit L2. During zooming, the second lens unit L2 is moved so that it is located closer to the image side at the telephoto end than at the wide-angle end, so that the second lens unit L2 has a large zooming effect. During zooming to the telephoto end compared to the wide-angle end, the third lens unit L3 moves along a locus convex toward the object side. During zooming, the first lens unit L1, the aperture stop SP, and the fourth lens unit L4 on the image side of the aperture stop SP are always fixed. As a result, the F number is kept constant in the zoom range from the wide angle end to the F drop point. The first lens unit L1 includes, in order from the object side to the image side, a first sub-lens unit L1a having a negative refractive power that does not move during focusing, and a second sub-lens group having a positive refractive power that moves on the optical axis during focusing. L1b comprises a third sub-lens group L1c having a fixed positive refractive power at the time of focusing. When focusing is performed, an inner focus method in which focusing is performed by moving the second sub-lens group L1b of the first lens group on the optical axis is employed. When focusing from infinity to a short distance, the second sub-lens group L1b moves on the optical axis to the image side.

  12A, 12B, and 12C are aberration diagrams at the wide-angle end, an intermediate zoom position, and a telephoto end when focusing on infinity according to the sixth embodiment.

  FIG. 13 is a lens cross-sectional view at the wide angle end according to the seventh embodiment. Example 7 is a zoom lens having a zoom ratio of 117.60 times and an aperture ratio of about 1.78 to 5.19.

  The zoom lens according to the seventh embodiment includes the following lens units arranged in order from the object side to the image side. A first lens unit L1 having a positive refractive power, a second lens unit L2 having a negative refractive power, a third lens unit L3 having a positive refractive power, a fourth lens unit L4 having a negative refractive power, an aperture stop SP, The fifth lens unit L5 having a refractive power includes five lens units. During zooming, the first lens unit L1 and the fifth lens unit L5 do not move. During zooming from the wide-angle end to the telephoto end, the second lens unit L2 moves to the image side, the third lens unit moves to the object side, and the fourth lens unit L4 moves to the object side. The zoom lens according to the seventh embodiment performs main zooming by moving the second lens unit L2. During zooming, the second lens unit L2 is moved so that it is located closer to the image side at the telephoto end than at the wide-angle end, so that the second lens unit L2 has a large zooming effect. During zooming, the first lens unit L1, the aperture stop SP, and the fifth lens unit L5 on the image side of the aperture stop SP are always fixed. As a result, the F number is kept constant in the zoom range from the wide angle end to the F drop point. Further, in order to reduce the number of lenses in the first lens unit L1 due to high performance and to reduce the size of the lens, it is important to use anomalous dispersion glass which is a high refractive index material. The first lens unit L1 includes, in order from the object side to the image side, a first sub-lens unit L1a having a negative refractive power that does not move during focusing, and a second sub-lens group having a positive refractive power that moves on the optical axis during focusing. L1b includes a third sub-lens group L1c having a positive refractive power that moves on the optical axis during focusing. When focusing is performed from infinity to a short distance, floating is performed in which the second sub-lens group L1b and the third sub-lens group L1c of the first lens group L1 are moved on the optical axis with different trajectories to perform focusing. The inner focus type is adopted. When focusing from infinity to a short distance, the second sub-lens group L1b and the third sub-lens group L1c move on the optical axis to the object side. At this time, the movement amount of the second sub-lens group L1b is larger than that of the third sub-lens group L1c.

  14A, 14B, and 14C are aberration diagrams at the wide-angle end, an intermediate zoom position, and a telephoto end when focusing on infinity according to the seventh embodiment.

  FIG. 15 is a lens cross-sectional view at the wide angle end according to the eighth embodiment. Example 8 is a zoom lens having a magnification ratio of 30.00 and an aperture ratio of about 1.52 to 2.19.

  The zoom lens according to the eighth embodiment includes the following lens units arranged in order from the object side to the image side. A first lens unit L1 having a positive refractive power, a second lens unit L2 having a negative refractive power, a third lens unit L3 having a positive refractive power, a fourth lens unit L4 having a positive refractive power, a stop SP, and positive refraction The fifth lens unit L5 includes five lens units. During zooming, the first lens unit L1, the fifth lens unit L5, and the aperture stop SP do not move. During zooming from the wide-angle end to the telephoto end, the second lens group moves toward the image side, the third lens group moves along a locus convex toward the object side, and the fourth lens group moves along a locus convex toward the object side. . The zoom lens of Example 8 performs main zooming by moving the second lens unit L2. During zooming, the second lens unit L2 is moved so that it is located closer to the image side at the telephoto end than at the wide-angle end, so that the second lens unit L2 has a large zooming effect. Also, during zooming, the aperture stop SP and the fifth lens unit L5 on the image side of the aperture stop SP are always fixed, so that the F number is kept constant in the zoom range from the wide angle end to the F drop point. . The first lens unit L1 includes, in order from the object side to the image side, a first sub lens unit L1a having a fixed negative refractive power during focusing, and a second sub lens unit having a positive refractive power moving on the optical axis during focusing. L1b comprises a third sub-lens group L1c having a positive refractive power that does not move during focusing. When focusing is performed, an inner focus type in which the second sub lens unit L1b of the first lens unit L1 is moved on the optical axis to perform focusing is adopted. When focusing from infinity to a short distance, the second sub-lens group L1b moves on the optical axis to the image side.

  FIGS. 16A, 16B, and 16C are aberration diagrams at the wide-angle end, an intermediate zoom position, and a telephoto end when focusing on infinity according to the eighth embodiment.

  FIG. 17 is a lens cross-sectional view at a wide angle end according to a ninth embodiment. Example 9 is a zoom lens having a zoom ratio of 9.79 and an aperture ratio of about 1.90 to 2.88.

  The zoom lens according to the ninth embodiment includes the following lens groups arranged in order from the object side to the image side. Four first lens group L1 having positive refractive power, second lens group L2 having negative refractive power, aperture stop SP, third lens group L3 having positive refractive power, and fourth lens group L4 having positive refractive power. It is composed of a lens group. During zooming from the wide-angle end to the telephoto end, the first lens group and the aperture stop SP are stationary during zooming, the second lens group moves toward the image side, and the third lens group moves along a locus convex toward the object side. The fourth lens group moves along a locus convex toward the object side. By making the first lens group immovable during zooming, zooming with the entire length of the lens maintained is facilitated. The zoom lens according to the ninth embodiment performs main zooming by moving the second lens group. During zooming, the second lens unit L2 is moved so that it is located closer to the image side at the telephoto end than at the wide-angle end, so that the second lens unit L2 has a large zooming effect. In zooming, the third lens unit L3 is moved to the object side at the telephoto end compared to the wide-angle end, thereby securing a focus space for the fourth lens unit L4 for focusing. The fourth lens unit L4 employs a rear focus type that performs focusing by moving on the optical axis. Then, the fourth lens group is moved to correct the image plane fluctuation caused by zooming, and to perform focusing. By making the movement locus of the fourth lens unit L4 convex during zooming toward the object side, the space between the third lens unit L3 and the fourth lens unit L4 is effectively used, and the overall length of the lens is effectively reduced. are doing.

  18A, 18B, and 18C are aberration diagrams at the wide-angle end, an intermediate zoom position, and a telephoto end when focusing on infinity according to the ninth embodiment.

  FIG. 19 is a lens cross-sectional view at the wide-angle end according to the tenth embodiment. Example 10 is a zoom lens having a zoom ratio of 11.73 times and an aperture ratio of about 1.92 to 2.88.

  In the zoom lens according to the tenth embodiment, the configuration of the lens units arranged in order from the object side to the image side is the same as that of the ninth embodiment. On the other hand, during zooming from the wide-angle end to the telephoto end, the first lens group moves toward the object side, the second lens group moves toward the image side, and the third lens group moves along a locus convex toward the object side. The four lens groups move along a locus convex toward the object side. In the zoom lens, the aperture stop SP does not move. During zooming from the wide-angle end to the telephoto end, the first lens unit moves toward the object side, thereby facilitating achievement of a high zoom ratio.

  20A, 20B, and 20C are aberration diagrams at the wide-angle end, an intermediate zoom position, and a telephoto end when focusing on infinity according to the tenth embodiment.

  FIG. 21 is a lens cross-sectional view at the wide-angle end according to the eleventh embodiment. Example 11 is a zoom lens having a magnification ratio of 41.54 and an aperture ratio of about 2.01 to 4.90.

  The zoom lens according to the eleventh embodiment includes the following lens units arranged in order from the object side to the image side. A first lens unit L1 having a positive refractive power, a second lens unit L2 having a negative refractive power, an aperture stop SP, a third lens unit L3 having a positive refractive power, a fourth lens unit L4 having a negative refractive power, The fifth lens unit L5 having a refractive power includes five lens units. During zooming, the first lens unit L1, the fifth lens unit L5, and the aperture stop SP do not move. During zooming from the wide-angle end to the telephoto end, the second lens unit L2 moves to the image side, the third lens unit L3 moves along a locus convex toward the object side, and the fourth lens unit L4 moves to the second lens unit L2. Move along a locus convex toward the image side so as to correct the image plane variation due to the movement of the third lens unit L3. The zoom lens according to the tenth embodiment performs main zooming by moving the second lens unit L2. During zooming, the second lens unit L2 is moved so that it is located closer to the image side at the telephoto end than at the wide-angle end, so that the second lens unit L2 has a large zooming effect. The fourth lens unit L4 employs a rear focus type that performs focusing by moving on the optical axis. Then, the fourth lens unit L4 is moved to correct the image plane fluctuation due to zooming, and to perform focusing.

  22A, 22B, and 22C are aberration diagrams at the wide-angle end, an intermediate zoom position, and a telephoto end when focusing on infinity according to the eleventh embodiment.

  FIG. 23 is a lens cross-sectional view at a wide-angle end according to a twelfth embodiment. Example 12 is a zoom lens having a zoom ratio of 40.92 times and an aperture ratio of about 2.01 to 4.95.

  The zoom lens according to the twelfth embodiment includes the following lens units arranged in order from the object side to the image side. A first lens unit L1 having a positive refractive power, a second lens unit L2 having a negative refractive power, a third lens unit L3 having a negative refractive power, an aperture stop SP, a fourth lens unit L4 having a positive refractive power, and a negative lens unit. The fifth lens unit L5 has a refractive power and the sixth lens unit L6 has a positive refractive power. During zooming, the first lens unit L1, the sixth lens unit L6, and the aperture stop SP do not move. During zooming from the wide-angle end to the telephoto end, the second lens unit L2 and the third lens unit L3 move toward the image side, the fourth lens unit L4 moves along a locus convex toward the object side, and the fifth lens unit L5 moves. Moves along a locus convex toward the image side so as to correct image plane fluctuation due to movement of the second lens unit L2, the third lens unit L3, and the fourth lens unit L4. In the zoom lens according to the twelfth embodiment, main zooming is performed by moving the second lens unit L2 and the third lens unit L3. During zooming, by moving the second lens unit L2 and the third lens unit L3 so as to be positioned on the image side at the telephoto end compared to the wide-angle end, a large zooming effect is provided on the second lens unit L2 and the third lens unit L3. Have. The fifth lens unit L5 employs a rear focus type that performs focusing by moving on the optical axis. Then, the fifth lens unit L5 is moved to correct the image plane fluctuation due to zooming, and to perform focusing.

  FIGS. 24A, 24B, and 24C are aberration diagrams at the wide-angle end, an intermediate zoom position, and a telephoto end in Example 12 upon focusing on infinity.

[Embodiment of Imaging Device]
Next, an embodiment of a TV camera (imaging apparatus) using the zoom lens of the present invention as an imaging optical system will be described with reference to FIG. In FIG. 26, reference numeral 101 denotes any one of the zoom lenses according to the first to eighth embodiments. Reference numeral 124 denotes a camera. The zoom lens 101 is detachable from the camera 124. Reference numeral 125 denotes an imaging apparatus configured by attaching the zoom lens 101 to the camera 124. The zoom lens 101 includes a first lens unit F, a zoom unit LZ, and a lens unit R for imaging. The first lens group F includes a lens group that moves during focusing.

  The zoom unit LZ includes at least two or more lens groups that move during zooming. An aperture stop SP, a lens unit R1, a lens unit R2, and a lens unit R3 are arranged on the image side of the zoom unit LZ, and have a lens unit IE that can be inserted and removed from the optical path. By inserting the lens unit IE between the lens group R1 and the lens group R2, the focal length range of the entire system of the zoom lens 101 is displaced.

  Reference numerals 114 and 115 denote driving mechanisms, such as a helicoid and a cam, for driving the first lens unit F and the LZ of the zoom unit in the optical axis direction. Reference numerals 116 to 118 denote motors (drive means) for electrically driving the drive mechanisms 114 and 115 and the aperture stop SP.

  Reference numerals 119 to 121 denote detectors such as encoders, potentiometers, and photosensors for detecting the positions on the optical axis of the first lens unit F and the zoom portion LZ, and the aperture diameter of the aperture stop SP. In the camera 124, reference numeral 109 denotes a glass block corresponding to an optical filter and a color separation optical system in the camera 124, and reference numeral 110 denotes an imaging element (photoelectric conversion element) such as a CCD sensor or a CMOS sensor that receives a subject image formed by the zoom lens 101. ). Reference numerals 111 and 122 denote CPUs (control units) for controlling various driving of the camera 124 and the zoom lens 101.

  As described above, by applying the zoom lens of the present invention to a television camera, an imaging device having high optical performance is realized.

  Next, numerical data 1 to 12 corresponding to the first to twelfth embodiments of the present invention are shown. In each numerical data, i indicates the order of the surface from the object side.

  ri is the radius of curvature of the i-th lens surface in order from the object side, di is the lens thickness or air gap between the i-th surface and the (i + 1) th surface in order from the object side, and ndi and νdi are the i-th surface in order from the object side. Are the refractive index and Abbe number of the lens material between the i and i + 1 surfaces.

  BF is a back focus, which is represented by a distance in air conversion from the last lens surface to the image surface. The total lens length is a value obtained by adding the back focus to the distance from the first lens surface to the final lens surface.

The aspherical shape in the aspherical surface data is represented by the following equation. Here, the optical axis is the X axis, the axis orthogonal to the optical axis is the H axis, and the traveling direction of light is the positive direction of the X axis. Further, R is a paraxial radius of curvature, k is a conic constant, and each of A2, A4, A6, A8, A10, A12, A14, and A16 is an aspheric coefficient.

In each aspherical shape, [e−X] means [× 10 ^−X ]. In addition to the specifications such as the focal length and the F number, the half angle of view and the image height of the entire system are the maximum image heights that determine the half angle of view. Each lens group data indicates the focal length of each lens group.

The portion where the distance d between the optical surfaces is (variable) changes during zooming, and a separate table shows the surface distance according to the focal length. Table 1 shows the calculation results of the conditional expressions based on the lens data of Numerical Examples 1 to 12 described below. In Table 1, the positive lens Gp included in the first lens group of each embodiment is identified by the number i as the i-th lens element counted from the object side, and includes a plurality of positive lenses Gp. For the examples, numerical values for each positive lens Gp are described.

(Numerical Example 1)
Unit: mm

Surface data surface number i ri di ndi vdi
1 -169.778 2.30 1.72047 34.7
2 254.813 3.35
3 1251.398 2.30 1.80 100 35.0
4 76.979 16.11 1.49700 81.5
5 -122.039 0.40
6 124.547 7.78 1.43387 95.1
7 -475.080 6.90
8 106.869 9.61 1.61800 63.3
9 -218.758 0.15
10 57.696 5.08 1.73000 49.0
11 108.956 (variable)
12 49.124 0.90 1.88300 40.8
13 12.975 5.85
14 -57.407 6.56 1.80810 22.8
15 -12.717 0.70 1.88300 40.8
16 61.202 0.20
17 25.016 2.76 1.66680 33.0
18 65.076 (variable)
19 -27.028 0.70 1.75700 47.8
20 38.607 2.87 1.84649 23.9
21 -2631.666 (variable)
22 -221.887 3.66 1.63854 55.4
23 -33.463 0.15
24 81.325 3.70 1.51633 64.1
25 -79.121 (variable)
26 (aperture) ∞ 1.30
27 35.753 5.92 1.51742 52.4
28 -38.894 0.90 1.83481 42.7
29 85.495 32.40
30 65.663 4.58 1.56384 60.7
31 -45.524 0.25
32 -112.716 1.18 1.83403 37.2
33 22.618 6.50 1.48749 70.2
34 -112.436 0.29
35 464.409 4.29 1.56384 60.7
36 -40.330 1.20 1.83481 42.7
37 -132.442 6.72
38 36.993 5.01 1.55000 56.8
39 -124.401 4.00
40 ∞ 33.00 1.60859 46.4
41 ∞ 13.20 1.51633 64.1
42 ∞ 8.00
Image plane ∞

Various data Zoom ratio 17.00
Wide-angle medium telephoto focal length 8.06 33.43 136.96
F-number 1.91 1.92 2.52
Half angle of view (degrees) 34.32 9.34 2.30
Image height 5.50 5.50 5.50
Total lens length 272.76 272.76 272.76
BF 8.00 8.00 8.00

d11 0.80 32.92 47.01
d18 49.21 10.36 12.26
d21 6.22 11.27 1.79
d25 5.74 7.43 0.91

Zoom lens group data group Start surface Focal length
1 1 61.00
2 12 -13.50
3 19 -39.48
4 22 34.61
5 26 49.21

(Numerical example 2)
Unit: mm

Surface data surface number i ri di ndi vdi
1 -169.778 2.30 1.72047 34.7
2 254.813 3.35
3 1251.398 2.30 1.80 100 35.0
4 76.979 16.11 1.49700 81.5
5 -122.039 0.40
6 124.547 7.78 1.43387 95.1
7 -475.080 6.90
8 106.869 9.61 1.61800 63.3
9 -218.758 0.15
10 57.696 5.08
11 108.956 (variable)
12 49.124 0.90 1.88300 40.8
13 12.975 5.85
14 -57.407 6.56 1.80810 22.8
15 -12.717 0.70 1.88300 40.8
16 61.202 0.20
17 25.016 2.76 1.66680 33.0
18 65.076 (variable)
19 -27.028 0.70 1.75700 47.8
20 38.607 2.87 1.84649 23.9
21 -2631.666 (variable)
22 -221.887 3.66 1.63854 55.4
23 -33.463 0.15
24 81.325 3.70 1.51633 64.1
25 -79.121 (variable)
26 (aperture) ∞ 1.30
27 35.753 5.92 1.51742 52.4
28 -38.894 0.90 1.83481 42.7
29 85.495 32.40
30 66.310 4.55 1.49700 81.5
31 -45.834 0.27
32 -470.913 1.19 1.83403 37.2
33 22.369 5.71 1.48749 70.2
34 447.229 4.26
35 353.595 4.46 1.50127 56.5
36 -38.170 2.21 1.83481 42.7
37 -74.372 2.04
38 35.188 5.33 1.65000 65.5
39 1949.659 4.00
40 ∞ 33.00 1.60859 46.4
41 ∞ 13.20 1.51633 64.1
42 ∞ 8.17
Image plane ∞

Various data Zoom ratio 17.00
Wide-angle medium telephoto focal length 8.05 33.42 136.88
F-number 1.91 1.92 2.52
Half angle of view (degrees) 34.34 9.35 2.30
Image height 5.50 5.50 5.50
Total lens length 272.92 272.92 272.92
BF 8.17 8.17 8.17

d11 0.80 32.92 47.01
d18 49.21 10.36 12.26
d21 6.22 11.27 1.79
d25 5.74 7.43 0.91

Zoom lens group data group Start surface Focal length
1 1 61.00
2 12 -13.50
3 19 -39.48
4 22 34.61
5 26 49.21

(Numerical example 3)
Unit: mm

Surface data surface number i ri di ndi vdi
1 -169.778 2.30 1.72047 34.7
2 254.813 3.35
3 1251.398 2.30 1.80 100 35.0
4 76.979 16.11 1.49700 81.5
5 -122.039 0.40
6 124.547 7.78 1.43387 95.1
7 -475.080 6.90
8 106.869 9.61 1.61800 63.3
9 -218.758 0.15
10 57.696 5.08
11 108.956 (variable)
12 49.124 0.90 1.88300 40.8
13 12.975 5.85
14 -57.407 6.56 1.80810 22.8
15 -12.717 0.70 1.88300 40.8
16 61.202 0.20
17 25.016 2.76 1.66680 33.0
18 65.076 (variable)
19 -27.028 0.70 1.75700 47.8
20 38.607 2.87 1.84649 23.9
21 -2631.666 (variable)
22 -221.887 3.66 1.63854 55.4
23 -33.463 0.15
24 81.325 3.70 1.51633 64.1
25 -79.121 (variable)
26 (aperture) ∞ 1.30
27 35.753 5.92 1.51742 52.4
28 -38.894 0.90 1.83481 42.7
29 85.495 30.15
30 66.094 4.56 1.49700 81.5
31 -45.731 0.27
32 -323.429 1.19 1.83403 37.2
33 23.844 5.06 1.48749 70.2
34 136.843 6.70
35 63.596 5.85 1.50127 56.5
36 -32.953 2.21 1.83481 42.7
37 -60.663 1.20
38 33.018 5.22 1.48107 80.0
39 264.618 4.00
40 ∞ 33.00 1.60859 46.4
41 ∞ 13.20 1.51633 64.1
42 ∞ 7.13
Image plane ∞

Various data Zoom ratio 17.00
Wide-angle medium telephoto focal length 8.04 33.36 136.64
F-number 1.91 1.91 2.51
Half angle of view (degrees) 34.38 9.36 2.30
Image height 5.50 5.50 5.50
Total lens length 271.87 271.87 271.87
BF 7.13 7.13 7.13

d11 0.80 32.92 47.01
d18 49.21 10.36 12.26
d21 6.22 11.27 1.79
d25 5.74 7.43 0.91

Zoom lens group data group Start surface Focal length
1 1 61.00
2 12 -13.50
3 19 -39.48
4 22 34.61
5 26 49.21

(Numerical example 4)
Unit: mm

Surface data surface number i ri di ndi vdi
1 -169.778 2.30 1.72047 34.7
2 254.813 3.35
3 1251.398 2.30 1.80 100 35.0
4 76.979 16.11 1.49700 81.5
5 -122.039 0.40
6 124.547 7.78 1.43387 95.1
7 -475.080 6.90
8 106.869 9.61 1.61800 63.3
9 -218.758 0.15
10 57.696 5.08 1.73000 49.0
11 108.956 (variable)
12 49.124 0.90 1.88300 40.8
13 12.975 5.85
14 -57.407 6.56 1.80810 22.8
15 -12.717 0.70 1.88300 40.8
16 61.202 0.20
17 25.016 2.76 1.66680 33.0
18 65.076 (variable)
19 -27.028 0.70 1.75700 47.8
20 38.607 2.87 1.84649 23.9
21 -2631.666 (variable)
22 -221.887 3.66 1.63854 55.4
23 -33.463 0.15
24 81.325 3.70 1.51633 64.1
25 -79.121 (variable)
26 (aperture) ∞ 1.30
27 35.753 5.92 1.51742 52.4
28 -38.894 0.90 1.83481 42.7
29 85.495 32.40
30 67.370 4.51 1.65000 55.0
31 -46.338 0.24
32 -79.826 1.18 1.83403 37.2
33 22.718 6.90 1.48749 70.2
34 -69.682 0.29
35 305.862 4.27 1.56384 60.7
36 -42.490 1.20 1.83481 42.7
37 -318.014 6.35
38 37.586 5.08 1.55000 56.8
39 -107.749 4.00
40 ∞ 33.00 1.60859 46.4
41 ∞ 13.20 1.51633 64.1
42 ∞ 7.61
Image plane ∞

Various data Zoom ratio 17.00
Wide-angle medium telephoto focal length 8.05 33.40 136.83
F-number 1.91 1.92 2.52
Half angle of view (degrees) 34.35 9.35 2.30
Image height 5.50 5.50 5.50
Total lens length 272.37 272.37 272.37
BF 7.61 7.61 7.61

d11 0.80 32.92 47.01
d18 49.21 10.36 12.26
d21 6.22 11.27 1.79
d25 5.74 7.43 0.91

Zoom lens group data group Start surface Focal length
1 1 61.00
2 12 -13.50
3 19 -39.48
4 22 34.61
5 26 49.21

(Numerical example 5)
Unit: mm

Surface data surface number i ri di ndi vdi
1 -169.778 2.30 1.72047 34.7
2 254.813 3.35
3 1251.398 2.30 1.80 100 35.0
4 76.979 16.11 1.49700 81.5
5 -122.039 0.40
6 124.547 7.78 1.43387 95.1
7 -475.080 6.90
8 106.869 9.61 1.61800 63.3
9 -218.758 0.15
10 57.696 5.08 1.73000 49.0
11 108.956 (variable)
12 49.124 0.90 1.88300 40.8
13 12.975 5.85
14 -57.407 6.56 1.80810 22.8
15 -12.717 0.70 1.88300 40.8
16 61.202 0.20
17 25.016 2.76 1.66680 33.0
18 65.076 (variable)
19 -27.028 0.70 1.75700 47.8
20 38.607 2.87 1.84649 23.9
21 -2631.666 (variable)
22 -221.887 3.66 1.63854 55.4
23 -33.463 0.15
24 81.325 3.70 1.51633 64.1
25 -79.121 (variable)
26 (aperture) ∞ 1.30
27 35.753 5.92 1.51742 52.4
28 -38.894 0.90 1.83481 42.7
29 85.495 32.40
30 65.911 4.57 1.56384 60.7
31 -45.643 0.25
32 -113.396 1.18 1.83403 37.2
33 22.824 6.24 1.48749 70.2
34 -167.387 0.29
35 238.527 4.09 1.48116 80.2
36 -48.665 1.20 1.83481 42.7
37 -102.513 7.30
38 36.070 4.90 1.55000 56.8
39 -167.278 4.00
40 ∞ 33.00 1.60859 46.4
41 ∞ 13.20 1.51633 64.1
42 ∞ 7.64
Image plane ∞

Various data Zoom ratio 17.00
Wide-angle medium telephoto focal length 8.06 33.44 136.96
F-number 1.91 1.92 2.52
Half angle of view (degrees) 34.32 9.34 2.30
Image height 5.50 5.50 5.50
Total lens length 272.40 272.40 272.40
BF 7.64 7.64 7.64

d11 0.80 32.92 47.01
d18 49.21 10.36 12.26
d21 6.22 11.27 1.79
d25 5.74 7.43 0.91

Zoom lens group data group Start surface Focal length
1 1 61.00
2 12 -13.50
3 19 -39.48
4 22 34.61
5 26 49.21

(Numerical example 6)
Unit: mm

Surface data surface number i ri di ndi vdi
1 ∞ 1.00
2 ∞ 4.00
3 ∞ 1.00
4 794.405 3.20 1.77250 49.6
5 61.483 23.90
6 -117.328 2.70 1.77250 49.6
7 420.939 0.19
8 145.462 7.13 1.92286 20.9
9 781.653 2.00
10 543.934 10.79 1.65000 65.5
11 * -138.725 0.20
12 622.621 15.01 1.49700 81.5
13 -76.527 2.50 1.80000 29.8
14 -131.842 6.48
15 119.988 2.50 1.73800 32.3
16 56.142 21.05 1.49700 81.5
17 -180.468 0.20
18 72.805 11.83 1.53715 74.8
19 -773.868 0.20
20 84.244 2.95 1.79000 45.5
21 94.537 (variable)
22 * 63.183 1.20 1.88 300 40.8
23 18.016 5.66
24 -99.851 4.19 1.84666 23.8
25 -22.617 0.70 1.77250 49.6
26 -98.979 2.20
27 -25.408 0.70 1.72916 54.7
28 153.099 0.16
29 53.647 3.90 1.65412 39.7
30 -80.735 (variable)
31 -34.231 0.90 1.65160 58.5
32 104.898 2.42 1.80810 22.8
33 -593.604 (variable)
34 (aperture) ∞ 1.29
35 789.965 4.34 1.75500 52.3
36 -62.245 0.20
37 68.487 5.16 1.61800 63.3
38 -177.905 0.20
39 59.636 5.52 1.49700 81.5
40 -150.686 1.20 2.00100 29.1
41 216.922 0.20
42 43.410 9.67 1.51633 64.1
43 -53.614 1.10 1.77250 49.6
44 88.071 20.42
45 38.782 5.22 1.48749 70.2
46 -52.623 0.20
47 27.302 5.50 1.48749 70.2
48 -44.953 1.00 2.00069 25.5
49 22.682 2.60
50 159.989 7.14 1.80810 22.8
51 -15.899 1.00 1.88300 40.8
52 260.119 9.05
53 35.452 4.49 1.59410 60.5
54 318.754 38.39
Image plane ∞
Aspheric surface 8th surface
K = 1.37949e + 000 A 4 = 2.10963e-007 A 6 = 2.49669e-011 A 8 = -8.31143e-014 A10 = 1.33469e-016 A12 = -1.15159e-019 A14 = 4.94652e-023 A16 =- 8.37959e-027

Page 19
K = 3.22264e + 000 A 4 = 1.50250e-006 A 6 = -1.35456e-008 A 8 = 7.91301e-011 A10 = -5.49408e-013 A12 = 2.11357e-015 A14 = -3.81816e-018 A16 = 1.81480e-021

Various data Zoom ratio 8.00
Wide-angle medium telephoto focal length
F-number 2.80 2.80 3.62
Half angle of view (degrees) 37.86 12.52 5.55
Image height 15.55 15.55 15.55
Total lens length 316.17 316.17 316.17
BF 38.39 38.39 38.39

d18 0.69 33.24 44.35
d27 41.36 5.87 6.17
d30 9.40 12.33 0.93

Zoom lens group data group Start surface Focal length
1 1 52.10
2 19 -21.50
3 28 -62.00
4 31 36.77

(Numerical example 7)
Unit: mm

Surface data surface number i ri di ndi vdi
1 -3486.328 6.00 1.83400 37.2
2 354.104 2.00
3 374.631 29.00 1.43387 95.1
4 -559.221 24.39
5 413.181 21.50 1.43387 95.1
6 -1553.164 0.25
7 292.316 20.00 1.43387 95.1
8 1699.310 2.03
9 196.535 23.20 1.49700 81.5
10 767.984 (variable)
11 * 1157.575 2.20 2.00330 28.3
12 49.905 8.00
13 -108.364 1.45 1.81600 46.6
14 41.542 9.52 1.92286 18.9
15 -111.205 2.50
16 -54.058 2.20 1.83400 37.2
17 272.771 (variable)
18 120.317 11.50 0.00000 67.0
19 * -389.309 0.50
20 223.990 10.00 0.00000 67.0
21 -361.940 0.20
22 121.701 2.00 1.84666 23.8
23 59.931 18.00 1.43875 94.9
24 -508.615 0.50
25 121.276 8.00 0.00000 67.0
26 * -2108.445 (variable)
27 -321.841 1.40 1.88300 40.8
28 36.044 8.00 1.80810 22.8
29 739.664 (variable)
30 (aperture) ∞ (variable)
31 -45.981 2.00 1.88300 40.8
32 -6420.334 2.00
33 79.836 5.00 1.80810 22.8
34 3941.032 2.00
35 10490.323 4.00 1.81600 46.6
36 133.354 8.00
37 -62.794 2.00 1.83400 37.2
38 69.354 11.00 1.51633 64.1
39 -44.181 1.00
40 -412.945 12.25 1.62041 60.3
41 -57.557 5.00
42 798.666 8.00 1.54072 47.2
43 -60.592 1.20
44 49.683 2.50 1.83400 37.2
45 24.852 9.50 1.48749 70.2
46 60.789 0.50
47 40.518 8.00 1.53172 48.8
48 -56.942 3.00 1.88300 40.8
49 33.466 2.00
50 28.696 8.63 1.55000 56.8
51 -112.410 5.00
52 ∞ 33.00 1.60859 46.4
53 ∞ 13.20 1.51633 64.2
54 5.00 5.00
Image plane ∞

Aspheric surface 11th surface
K = -7.30345e + 002 A 4 = 4.66948e-007 A 6 = -2.19251e-010 A 8 = 2.84425e-012 A10 = -6.60672e-015 A12 = 4.97117e-018

Page 19
K = 0.00000e + 000 A 4 = -5.96926e-008 A 6 = 9.70707e-011 A 8 = -2.28953e-014 A10 = -6.92120e-019 A12 = 1.30954e-021

Side 26
K = 0.00000e + 000 A 4 = 3.54390e-007 A 6 = 1.11606e-010 A 8 = -3.97683e-013 A10 = 3.46209e-016 A12 = -9.86702e-020

Various data Zoom ratio 117.60
Wide-angle medium telephoto focal length 8.93 60.77 1049.83
F-number 1.78 1.78 5.19
Half angle of view (degrees) 31.64 5.17 0.30
Image height 5.50 5.50 5.50
Total lens length 661.65 661.65 661.65
BF 5.00 5.00 5.00

d10 2.05 134.07 191.25
d17 281.20 125.77 2.00
d26 2.05 20.05 58.22
d29 1.22 6.64 35.04
d30 7.00 7.00 7.00

Zoom lens group data group Start surface Focal length
1 1 250.00
2 11 -25.70
3 18 66.00
4 27 -170.00
5 31 62.59

(Numerical example 8)
Unit: mm

Surface data surface number i ri di ndi vdi
1 986.400 4.70 1.77250 49.6
2 152.315 36.35
3 -389.257 4.50 1.77250 49.6
4 649.417 0.15
5 309.455 9.28 1.71736 29.5
6 773.725 10.00
7 -2927.374 14.00 1.49700 81.5
8 -260.740 0.20
9 2461.113 4.40 1.80518 25.4
10 290.226 15.00 1.49700 81.5
11 -629.504 44.00
12 532.816 17.08 1.49700 81.5
13 -273.087 0.15
14 458.740 12.43 1.49700 81.5
15 -632.796 0.15
16 334.033 8.64 1.60000 62.0
17 1546.906 (variable)
18 * 557.320 1.50 1.77250 49.6
19 97.578 5.64
20 438.891 1.50 1.72916 54.7
21 34.755 10.46 1.84666 23.8
22 94.827 6.11
23 -181.912 1.50 1.77250 49.6
24 88.343 (variable)
25 1034.760 6.25 1.62041 60.3
26 -139.471 0.15
27 134.131 11.11 1.48749 70.2
28 -81.275 0.09
29 -86.919 1.60 1.80518 25.4
30 -215.948 (variable)
31 88.441 1.60 1.80518 25.4
32 57.856 9.30 1.48749 70.2
33 416.792 0.15
34 * 90.932 7.65 1.62041 60.3
35 -557.289 (variable)
36 (aperture) ∞ 2.98
37 -132.172 1.40 1.78800 47.4
38 19.003 7.31 1.85478 24.8
39 -627.106 1.40 1.78800 47.4
40 70.223 5.93
41 -32.307 19.74 1.77250 49.6
42 169.224 8.40
43 -113.074 1.50 1.53775 74.7
44 1847.904 7.45 1.64000 60.1
45 -37.062 3.00
46 -123.577 1.50 2.00100 29.1
47 75.963 7.53 1.51633 64.1
48 -61.591 0.66
49 97.684 7.00 1.64000 66.1
50 -85.995 0.20
51 44.349 8.76 1.43875 94.9
52 -88.976 1.00
53 -99.527 1.50 2.00069 25.5
54 91.587 5.00 1.85896 22.7
55 -145.692 8.00
56 ∞ 33.00 1.60859 46.4
57 ∞ 13.20 1.51633 64.2
58 ∞ 10.00
Image plane ∞

Aspheric surface data No. 18
K = 0.00000e + 000 A 4 = 2.65507e-007 A 6 = -1.21934e-011 A 8 = -1.74017e-015 A10 = -3.97066e-017 A12 = 8.17590e-021

Side 34
K = 0.00000e + 000 A 4 = -4.99441e-008 A 6 = -4.51336e-010 A 8 = 9.51567e-013 A10 = -9.17379e-016 A12 = 3.23522e-019

Various data Zoom ratio 30.00
Wide-angle medium telephoto focal length 6.47 34.86 194.20
F-number 1.52 1.52 2.19
Half angle of view (degrees) 40.35 8.97 1.62
Image height 5.50 5.50 5.50
Total lens length 625.00 625.00 625.00
BF 10.00 10.00 10.00

d17 3.00 93.37 214.58
d24 216.24 59.28 6.33
d30 2.67 40.45 1.00
d35 1.00 29.81 1.00

Zoom lens group data group Start surface Focal length
1 1 178.92
2 18 -39.67
3 25 110.08
4 31 98.28
5 36 31.00

(Numerical example 9)
Unit: mm

Surface data surface number i ri di ndi vdi
1 53.929 1.35 1.84666 23.9
2 27.821 6.05 1.60311 60.6
3 -361.752 0.20
4 24.138 3.19 1.69680 55.5
5 67.371 (variable)
6 126.531 0.80 1.83481 42.7
7 7.059 3.00
8 -900.568 0.70 1.83481 42.7
9 18.242 1.57
10 -20.961 0.60 1.83481 42.7
11 367.479 0.14
12 22.388 1.83 1.92286 18.9
13 -54.238 (variable)
14 (aperture) ∞
15 * 9.783 2.55 1.58313 59.4
16 -133.067 3.64
17 52.501 0.72 1.80518 25.4
18 9.744 1.53
19 * 15.015 2.05 1.58313 59.4
20 -42.749 (variable)
21 15.391 4.00 1.61000 66.6
22 -23.736 0.70 1.84666 23.9
23 -75.701 (variable)
24 ∞ 2.95 1.51633 64.1
25 ∞ 0.51
Image plane ∞

15th surface of aspherical data
K = -1.24240e + 000 A 4 = 6.61444e-005 A 6 = -2.82208e-008 A 8 = 1.79705e-009

Page 19
K = -4.16889e-001 A 4 = -5.53737e-005

Various data Zoom ratio 9.79
Wide-angle Medium telephoto focal length 4.44 13.14 43.46
F-number 1.90 2.42 2.88
Half angle of view 34.32 12.98 3.99
Image height 3.03 3.03 3.03
Total lens length 78.24 78.24 78.24
BF 0.51 0.51 0.51

d 5 0.93 12.21 21.44
d13 22.42 11.14 1.91
d14 6.22 1.93 2.66
d20 4.81 5.75 5.58
d23 5.78 9.14 8.57

Zoom lens group data group Start surface Focal length
1 1 36.84
2 6 -7.16
3 15 19.22
4 21 24.63

(Numerical example 10)
Unit: mm

Surface data surface number i ri di ndi vdi
1 53.929 1.35 1.84666 23.9
2 27.821 6.05 1.60311 60.6
3 -361.752 0.20
4 24.138 3.19 1.69680 55.5
5 67.371 (variable)
6 126.531 0.80 1.83481 42.7
7 7.059 3.00
8 -900.568 0.70 1.83481 42.7
9 18.242 1.57
10 -20.961 0.60 1.83481 42.7
11 367.479 0.14
12 22.388 1.83 1.92286 18.9
13 -54.238 (variable)
14 (aperture) ∞
15 * 9.783 2.95 1.58313 59.4
16 -120.096 3.82
17 61.676 0.70 1.80518 25.4
18 9.580 0.46
19 * 15.015 2.21 1.58313 59.4
20 -47.561 (variable)
21 13.746 2.96 1.59410 60.5
22 -24.639 0.70 1.84666 23.9
23 -65.215 (variable)
24 ∞ 2.95 1.51633 64.1
25 ∞ 1.24
Image plane ∞

15th surface of aspherical data
K = -1.24240e + 000 A 4 = 6.61444e-005 A 6 = -2.82208e-008 A 8 = 1.79705e-009

Page 19
K = -4.16889e-001 A 4 = -5.53737e-005

Various data Zoom ratio 11.73
Wide-angle Medium telephoto focal length 4.53 14.00 53.11
F-number 1.92 2.42 2.88
Half angle of view (degrees) 33.78 12.21 3.26
Image height 3.03 3.03 3.03
Total lens length 77.59 78.14 78.59
BF 1.24 1.24 1.24

d 5 0.93 12.76 22.44
d13 22.42 11.14 1.91
d14 6.22 1.93 2.66
d20 4.81 5.56 7.44
d23 5.78 9.33 6.71

Zoom lens group data group Start surface Focal length
1 1 36.84
2 6 -7.16
3 15 19.69
4 21 21.95

(Numerical example 11)
Unit: mm

Surface data surface number i ri di ndi vdi
1 62.355 1.30 1.85478 24.8
2 37.710 4.94 1.49700 81.5
3 192.442 0.15
4 46.812 3.43 1.59522 67.7
5 225.681 0.10
6 31.010 3.51 1.59522 67.7
7 76.000 (variable)
8 87.603 0.60 1.95375 32.3
9 7.309 2.93
10 53.525 0.50 1.85 150 40.8
11 13.375 2.14
12 -20.387 0.50 1.77250 49.6
13 53.565 0.10
14 20.354 2.06 1.95906 17.5
15 -57.827 (variable)
16 (aperture) ∞
17 * 13.276 4.15 1.76450 49.1
18 27.241 0.50
19 13.657 0.98 2.00100 29.1
20 7.056 2.00 1.43700 95.1
21 8.679 0.79
22 * 7.681 6.00 1.49700 81.5
23 * -12.855 (variable)
24 207.423 2.00 1.95375 32.3
25 6.527 (variable)
26 12.622 3.00 1.65000 55.0
27 -15.882 2.28
28 ∞ 2.00 1.51633 64.1
29 ∞
Image plane ∞ 0.51

17th surface of aspherical data
K = -1.10884e + 000 A 2 = 1.05658e-002 A 4 = 1.01064e-004 A 6 = 1.22831e-007 A 8 = 1.22160e-009 A10 = -1.19281e-011

Side 22
K = 4.04079e-001 A 4 = -5.15700e-004 A 6 = -7.28653e-006 A 8 = 5.30036e-010 A10 = -5.65112e-009

Side 23
K = -7.86419e-001 A 4 = 2.38274e-005 A 6 = -3.52404e-006 A 8 = 9.78293e-010 A10 = -1.11232e-009

Various data Zoom ratio 41.54
Wide-angle medium telephoto focal length 4.09 46.91 169.88
F-number 2.01 3.00 4.90
Half angle of view 38.04 3.90 1.08
Image height 3.20 3.20 3.20
Total lens length 90.46 90.46 90.46
BF 0.51 0.51 0.51

d 7 0.60 25.19 30.59
d15 30.79 6.20 0.80
d16 6.39 1.18 0.60
d23 4.22 9.30 2.12
d25 1.98 2.11 9.87

Zoom lens group data group Start surface Focal length
1 1 43.58
2 8 -6.39
3 17 13.30
4 24 -7.10
5 26 11.29

(Numerical example 12)
Unit: mm

Surface data surface number i ri di ndi vdi
1 62.355 1.30 1.85478 24.8
2 37.710 4.94 1.49700 81.5
3 192.442 0.15
4 46.812 3.43 1.59522 67.7
5 225.681 0.10
6 31.010 3.51 1.59522 67.7
7 76.000 (variable)
8 87.603 0.60 1.95375 32.3
9 7.309 (variable)
10 53.525 0.50 1.85 150 40.8
11 13.375 2.14
12 -20.387 0.50 1.77250 49.6
13 53.565 0.10
14 20.354 2.06 1.95906 17.5
15 -57.827 (variable)
16 (aperture) ∞
17 * 13.276 4.15 1.76450 49.1
18 27.241 0.50
19 13.657 0.98 2.00100 29.1
20 7.056 2.00 1.43700 95.1
21 8.679 0.79
22 * 7.681 6.00 1.49700 81.5
23 * -12.855 (variable)
24 207.423 2.00 1.95375 32.3
25 6.527 (variable)
26 12.622 3.00 1.65000 55.0
27 -15.882 (variable)
28 ∞ 2.00 1.51633 64.1
29 ∞ 0.51
Image plane ∞

17th surface of aspherical data
K = -1.10884e + 000 A 2 = 1.05658e-002 A 4 = 1.01064e-004 A 6 = 1.22831e-007 A 8 = 1.22160e-009 A10 = -1.19281e-011

Side 22
K = 4.04079e-001 A 4 = -5.15700e-004 A 6 = -7.28653e-006 A 8 = 5.30036e-010 A10 = -5.65112e-009

Side 23
K = -7.86419e-001 A 4 = 2.38274e-005 A 6 = -3.52404e-006 A 8 = 9.78293e-010 A10 = -1.11232e-009

Various data Zoom ratio 42.92
Wide-angle medium telephoto focal length 4.09 46.87 175.51
F-number 2.01 3.00 4.95
Half angle of view 38.04 3.91 1.04
Image height 3.20 3.20 3.20
Total lens length 90.46 90.46 90.46
BF 0.51 0.51 0.51

d 7 0.60 25.19 30.59
d 9 2.93 3.75 3.93
d15 30.79 5.38 -0.20
d16 6.39 1.18 0.60
d23 4.22 9.62 2.11
d25 1.98 1.79 9.89
d27 2.28 2.28 2.28

Zoom lens group data group Start surface Focal length
1 1 43.58
2 8 -8.39
3 10 -31.09
4 17 13.30
5 24 -7.10
6 26 11.29

L1 First lens unit L2 Second lens unit L3 Third lens unit L4 Fourth lens unit L5 Fifth lens unit L6 Sixth lens unit

Claims (9)

A first lens unit having a positive refractive power, a second lens unit having a negative refractive power that moves for zooming, and at least one lens group that moves for zooming, in order from the object side to the image side. And a final lens group having a positive refractive power, wherein each set of adjacent lens groups changes in distance for zooming, and the final lens group includes a positive lens, and the Abbe of the positive lens. Assuming that the number and the partial dispersion ratio are νd and θgF, respectively, the conditional expression θgF − (− 1.6650 × ¹⁰⁻⁷ · νd ³ + 5.2130 × ¹⁰⁻⁵ · νd ² −5.6560 × 10 ⁻³ · νd + 0.7370 )> 0,
0.5450 <θgF, and 50.0 <νd <85.0
Satisfied
The distance on the optical axis from the stop at infinity focus and the wide-angle end to the vertex of the object-side surface of the positive lens is Dx, and the focus at infinity and the widest end at the wide-angle end is the most image side of the last lens group from the stop. 0.50 <Dx / DR <1.00, where DR is the distance on the optical axis to the vertex of the surface
Satisfy
A zoom lens characterized in that:
Here, the Abbe number νd and the partial dispersion ratio θgF are the materials of the g-line (wavelength 435.8 nm), F-line (486.1 nm), C-line (656.3 nm) and d-line (587.6 nm), respectively. Assuming that the refractive indices are Ng, NF, NC, and Nd, respectively, the expressions νd = (Nd−1) / (NF−NC), and θgF = (Ng−NF) / (NF−NC)
It is represented by   The zoom lens according to claim 1, wherein the stop is disposed between the second lens group and the last lens group. Assuming that the focal length of the positive lens is fp and the focal length of the last lens group at the wide-angle end is fR, conditional expression 0.50 <fp / fR <2.50
The zoom lens according to claim 1, wherein the following condition is satisfied. Assuming that the radius of curvature of the object-side surface of the positive lens is R1, and the radius of curvature of the image-side surface of the positive lens is R2, the conditional expression -2.0 <(R1 + R2) / (R1-R2) <1.5
The zoom lens according to any one of claims 1 to 3, wherein the following formula is satisfied. Assuming that the average linear expansion coefficient (10 ⁻⁵ / K) of the positive lens at −30 ° C. or more and + 70 ° C. or less is α, conditional expression: 0.50 <α <5.00
The zoom lens according to any one of claims 1 to 4, wherein the following formula is satisfied. Assuming that the refractive index of the positive lens is nd, conditional expression 1.550 <nd <1.750
The zoom lens according to any one of claims 1 to 5, wherein the following formula is satisfied. Assuming that the entire focal length at the wide-angle end is fW and the focal length of the last lens group at the wide-angle end is fR, conditional expression 1.00 <fR / fW <20.00
The zoom lens according to any one of claims 1 to 6, wherein the following formula is satisfied.   The zoom lens according to any one of claims 1 to 7, wherein the first lens group includes a negative lens and at least one positive lens in order from the object side to the image side. A zoom lens according to any one of claims 1 to 8,
An image sensor arranged on an image plane of the zoom lens;
An imaging device comprising:

Images