JP5984877B2 - Zoom lens and imaging apparatus having the same - Google Patents

Description

  The present invention relates to a zoom lens and an image pickup apparatus having the same, and is particularly suitable for a broadcast television camera, a movie camera, a video camera, a digital still camera, and the like.

  2. Description of the Related Art In recent years, large format cameras having a shallow depth of field and beautiful bokeh have been used for imaging devices such as a television camera, a movie camera, a video camera, and a photographic camera in order to expand image expression. As a zoom lens to be mounted on a large format camera, there is a demand for a zoom lens that is compact and lightweight, has a high zoom ratio, and has high optical performance in order to ensure mobility and improve the degree of freedom of photographing. As a zoom lens having a high zoom ratio, as proposed in Patent Documents 1 and 2, a positive lead type lens having a lens unit having a positive refractive power closest to the object side and including four or more lens units as a whole. Zoom lenses are known.

  Patent Document 1 proposes a zoom lens composed of four groups, having a telephoto end angle of view of about 0.7 degrees and a zoom ratio of about 15 times.

  Patent Document 2 proposes a zoom lens composed of four groups, having a telephoto end angle of view of about 1.6 degrees and a zoom ratio of about 3 times.

JP 2007-139858 A JP 2004-085846 A

  In general, when the image size of the image pickup apparatus increases, the zoom lens to be mounted increases accordingly. Therefore, as a zoom lens to be mounted on a large format camera, in order to achieve a large aperture ratio and a high zoom ratio while achieving improvement in mobility and freedom of photographing, it is a problem to reduce the size and weight of the lens. In order to reduce the size and weight of the zoom lens, it is important to reduce the size of the first lens group having the largest lens diameter and the zoom lens group in which the amount of movement increases as the zoom ratio increases.

  Compared to the zoom lens of Patent Document 1, the effective diameter of the variable power lens group is increased as a problem in increasing the zoom ratio while maintaining a large aperture ratio, corresponding to a larger image sensor. Since the mechanism for driving the lens increases in size, it is difficult to reduce the size of the entire lens.

  As a problem when further increasing the zoom ratio with respect to the zoom lens of Patent Document 2, it is difficult to suppress the movement amount of the third lens unit for image plane correction, and in addition, the total lens thickness of the first lens unit is large. Due to its large size, it is difficult to reduce the size of the entire lens.

  The present invention appropriately defines the paraxial refractive power arrangement of the first lens group and the lens group related to zooming with the first lens group, so that it corresponds to a large sensor, while having a large aperture ratio and a high zoom ratio, The objective is to achieve a zoom lens that is both compact and lightweight.

In order to achieve the above object, the zoom lens of the present invention has, in order from the object side to the image side, a first lens group having a positive refractive power that does not move for zooming, and a negative refractive power that moves during zooming. A second lens group having at least one lens group that moves during zooming, and a subsequent rear lens group , and the distance between adjacent lens groups changes during zooming, and the first lens group has a focusing function. A zoom lens having an eleventh sub-lens group that does not move for focusing and a twelfth sub-lens group having positive refractive power that moves during focusing,
The eleventh sub-lens group includes a negative lens and a positive lens, the focal length of the first lens group is f1, and the rear main of the eleventh sub-lens group from the most image side lens surface of the eleventh sub-lens group. The distance on the optical axis to the point position is OK11, the focal length of the zoom lens at the telephoto end is ft, and the rear principal point of the first lens group from the lens surface closest to the image side of the first lens group When the distance on the optical axis to the position is OK1 ,
-25.00 <OK11 / f1 <-0. 8 0
2.00 <ft / f1 <7.00
−0.30 <OK1 / f1 ≦ −0.11
It satisfies the following condition. However, the direction from the object side to the image side is a positive direction.

  According to the present invention, it is possible to achieve a zoom lens that is compatible with a large sensor and that is both compact and lightweight while having a large aperture ratio and a high zoom ratio.

FIG. 3 is a lens cross-sectional view at the wide-angle end of the zoom lens of Example 1 in an infinite focus state. FIG. 4 is a longitudinal aberration diagram of the zoom lens of Example 1 at an infinite focus state, at (A) a wide angle end, (B) a focal length of 400 mm, and (C) a telephoto end. FIG. 6 is a lens cross-sectional view at the wide-angle end of the zoom lens of Example 2 in an infinite focus state. FIG. 6 is a longitudinal aberration diagram of the zoom lens of Example 2 at an infinite focus state, at (A) a wide angle end, (B) a focal length of 500 mm, and (C) a telephoto end. FIG. 6 is a lens cross-sectional view at the wide-angle end of the zoom lens according to Embodiment 3 in an infinite focus state. FIG. 6 is a longitudinal aberration diagram at the wide-angle end, (B) a focal length of 180 mm, and (C) a telephoto end in an infinitely far focus state of the zoom lens according to the third exemplary embodiment. FIG. 6 is a lens cross-sectional view at the wide-angle end of the zoom lens of Example 4 in an infinite focus state. FIG. 10 is a longitudinal aberration diagram of the zoom lens of Example 4 at an infinite focus state, at (A) a wide angle end, (B) a focal length of 450 mm, and (C) a telephoto end. It is a principal part schematic of the imaging device of this invention. FIG. 3 is an optical path diagram of an on-axis marginal ray according to the first embodiment.

  Embodiments of a zoom lens according to the present invention will be described below in detail with reference to the accompanying drawings.

  The zoom lens of the present invention includes a positive first lens group that does not move for zooming in order from the object side to the image side. The zoom lens further includes a second lens unit having negative refractive power that moves during zooming, at least one lens unit for zooming or image plane correction accompanying zooming, and a subsequent rear unit Ur. Here, the lens group does not move for zooming because the lens group is not driven for the purpose of zooming, but if zooming and focusing are performed at the same time, it moves for focusing. It is possible.

  The zoom lens of each embodiment has a high zoom ratio and a high zoom ratio by appropriately determining the paraxial refractive power arrangement in the first lens group and the relation between the paraxial refractive power arrangement of the first lens group and the second lens group. Although it is a super-telephoto zoom lens, it is small and lightweight when it is compatible with large sensors.

Specifically, the zoom lens of the present invention includes a positive first lens group that does not move for zooming in order from the object side, a second lens group that has a negative refractive power that moves during zooming, and includes at least one group. It has a lens group for zooming or image plane correction accompanying zooming, and a rear group Ur following the lens group. The first lens group is a zoom lens having an eleventh sub lens group that is fixed during focusing (focus adjustment) and a positive twelfth sub lens group that moves in the optical axis direction during focusing . The eleventh sub lens group includes a negative lens and a positive lens. The focal length of the first lens group is f1, the distance from the most image side lens surface of the eleventh sub lens group to the rear principal point position of the eleventh sub lens group is OK 11, and the most image side lens of the first lens group When the distance from the surface to the rear principal point position of the first lens unit is OK1, and the focal length of the zoom lens at the telephoto end is ft,
−0.30 <OK1 / f1 ≦ −0.11 (1)
-25.00 <OK11 / f1 <-0. 8 0 (2)
2.00 <ft / f1 <7.00 (3)
Satisfy the following conditions. However, the direction from the object side to the image side along the optical axis is a positive direction.

  Conditional expression (1) defines the relationship between the focal length f1 of the first lens group and the distance OK1 from the most image-side lens surface of the first lens group to the rear principal point position of the first lens group. . In the following description, the distance from the most image-side lens surface of the i-th group to the rear principal point position of the i-th group will be defined and described as the rear principal point distance of the i-th group.

  Hereinafter, it demonstrates in detail using FIG. FIG. 10 is a schematic optical path diagram in the first embodiment. U11 to U4 in FIG. 10 are an eleventh sub-lens group to a fourth lens group, respectively. As shown in FIG. 10, by shifting the position of the rear principal point of the first lens group to the object side, the distance between the principal points of the first lens group and the second lens group is increased and is incident on the second lens group. The beam diameter can be reduced, and the aperture can be increased. Further, it is easy to reduce the diameter of the second lens group and the lens barrel for holding and driving them. However, in order to displace the rear principal point position of the first lens group to the object side, a positive lens group disposed on the object side and a negative refractive power disposed on the image side in the first lens group. It is necessary to increase the refractive power of each lens group having As a result, higher-order aberrations such as spherical aberration, coma aberration, and axial chromatic aberration are generated.

Thus, to appropriately set the ratio of the distance to the rear principal point position of the first lens from the lens surface on the most image-side focal distance and the first lens group of the first lens group, small size and light weight, high Necessary to achieve a balance of performance.

  When the upper limit of conditional expression (1) is exceeded, the amount of displacement of the rear principal point position of the first lens group toward the object side becomes too large, and the refractive power of each lens group in the first lens group becomes larger as described above. It becomes difficult to correct higher-order aberrations generated by the increase. When the lower limit of conditional expression (1) is exceeded, the displacement of the rear principal point position of the first lens group toward the object side becomes too small, and the lens diameter after the first lens group and a mechanism for holding and driving them are provided. It will increase and it will be difficult to achieve small size and light weight.

  Conditional expression (2) defines the relationship between the focal length f1 of the first lens group and the rear principal point distance of the eleventh sub-lens group.

  When the upper limit of conditional expression (2) is exceeded, the displacement amount of the rear principal point of the eleventh sub-lens group toward the object side becomes too large, and as described above, the refraction of each lens group within the eleventh sub-lens group. It becomes difficult to correct higher-order aberrations that occur when the force increases. When the lower limit of conditional expression (2) is exceeded, the displacement amount of the rear principal point of the first lens group toward the object side becomes too small, and the lens diameter after the first lens group and a mechanism for holding and driving them are provided. It will increase and it will be difficult to achieve small size and light weight.

  In the present invention, the eleventh sub-lens group has a role of largely displacing the rear principal point position of the first lens group toward the object side. When the role of displacing the rear principal point of the first lens group to the object side is shared by the twelfth sub lens group, it is necessary to dispose an element having a negative refractive power in the twelfth sub lens group as described above. There is. When an element having a negative refractive power is arranged in the twelfth sub lens group, the number of lenses increases to correct various aberrations such as axial chromatic aberration and spherical aberration in the lens group. Will become larger. Since the twelfth sub-lens group is a lens group that moves when focus adjustment is performed, the mechanism for driving the lens is increased in size, leading to an increase in power consumption and a further increase in weight.

  Conditional expression (3) defines the conditions for achieving both compactness, light weight, high magnification, and high performance by defining the ratio of the telephoto end focal length and the focal length of the first lens unit in the entire lens system. Yes.

  In order to achieve both a reduction in size and weight and an increase in magnification, it is desirable to reduce the focal length f1 of the first lens group. This is because if f1 is reduced, the image point position of the first lens group, that is, the object point position of the second lens group approaches the second lens group, so that the stroke amount necessary for zooming can be reduced.

However, if the focal length f1 of the first lens group is reduced, as shown in the equation (A), in order to obtain the focal length fm in the predetermined zoom lens, it is necessary to increase the imaging magnification after the first lens group. is there.
fm = f1 × β2m × β3m × βr (A)
β2m is the imaging magnification of the second lens group, and β3m is the imaging magnification of the third lens group. βr is the imaging magnification of the fourth lens group.

  If the imaging magnification after the first lens group is large, the enlargement ratio of spherical aberration, axial chromatic aberration, etc. occurring in the first lens group increases particularly at the telephoto end, and it becomes difficult to achieve high performance. . From the above, it is necessary to set the focal length of the first lens group within an appropriate range in order to achieve small size and light weight, high magnification, and high performance.

  When the upper limit of conditional expression (3) is exceeded, the focal length of the first lens unit with respect to the telephoto end focal length of the zoom lens becomes too small, making it difficult to achieve high performance. Below the lower limit of conditional expression (3), the focal length of the first lens group with respect to the telephoto end focal length of the zoom lens becomes too large, making it difficult to achieve a reduction in size and weight and an increase in magnification.

Preferably, the numerical range of conditional expression (3) is set as follows.
2.40 <ft / f1 <6.3 (3a)

  In each embodiment, it is more preferable to satisfy one or more of the following conditions.

As a further aspect of the zoom lens of the present invention, the relationship of dispersion of the optical material used in the eleventh sub-lens group is defined. When the average value of the Abbe number of the positive lens constituting the eleventh sub lens group is νd11p and the average value of the Abbe number of the negative lens constituting the first sub lens group is νd11n, the following conditional expression is satisfied: Is preferred.
20.00 <νd11p−νd11n <45.00 (4)

  By satisfying conditional expression (4), it becomes easy to achieve both axial chromatic aberration correction at the telephoto end and downsizing. Exceeding the upper limit of conditional expression (4) is advantageous for correcting chromatic aberration in the eleventh sub-lens group, but the refractive power of each lens constituting the eleventh sub-lens group becomes weak, and It is difficult to displace the rear principal point position farther toward the object side, which makes it difficult to reduce the size. If the lower limit of conditional expression (4) is not reached, in order to correct axial chromatic aberration at the telephoto end, the refractive power of the negative lens becomes too strong, and the radius of curvature at each lens surface becomes small. Higher-order aberrations of spherical aberration increase, making it difficult to obtain good optical performance.

More preferably, the numerical range of conditional expression (4) is set as follows.
23.000 <νd11p−νd11n <42.00 (4a)

As a further aspect of the zoom lens according to the present invention, an average value of dispersion of optical materials used in the twelfth sub lens group is defined. When the average value of the Abbe number of the lenses constituting the twelfth sub lens group is νd12, it is preferable that the following conditional expression is satisfied.
70.00 <νd12 <100.00 (5)

  By satisfying conditional expression (5), it is possible to suppress fluctuations in axial chromatic aberration during focus adjustment. Exceeding the upper limit of conditional expression (5) is advantageous for suppressing chromatic aberration fluctuations during focusing, but correction of axial chromatic aberration at the telephoto end becomes excessive, making it difficult to obtain good optical performance. If the lower limit of conditional expression (5) is not reached, it will be difficult to correct axial chromatic aberration at the telephoto end and axial chromatic aberration at the time of focusing, and good optical performance cannot be obtained.

More preferably, the numerical range of conditional expression (5) is set as follows.
75.00 <νd12 <97.00 (5a)

  As a further aspect of the zoom lens according to the present invention, the lens arrangement in the eleventh sub-lens group is defined. In the eleventh sub-lens group, it is preferable that the most object side lens is a positive lens and the most image side lens is a negative lens. By disposing the negative lens closest to the image side, the rear principal point distance of the eleventh sub-lens group can be easily increased more negatively. Further, by arranging the positive lens closest to the object side, it becomes easy to negatively increase the rear principal point distance of the eleventh sub lens unit. When it is disadvantageous to make the rear principal point position negatively large, the refractive power of the negative lens becomes extremely strong in order to displace the rear principal point position, so that axial chromatic aberration or higher-order spherical surface It becomes difficult to obtain good optical performance because it causes a large amount of aberration.

As a further aspect of the zoom lens of the present invention, the lens arrangement in the eleventh sub-lens group is defined in detail . It is preferable that the eleventh sub-lens group includes a positive lens, a negative lens, a positive lens, and a negative lens in order from the object side to the image side. By arranging the lenses in this order, it becomes easy to negatively increase the rear principal point distance of the eleventh sub-lens group, and in addition, the spherical aberration and axial chromatic aberration generated on each surface are corrected well. And high optical performance can be obtained at the telephoto end.

As a further aspect of the zoom lens of the present invention, the relationship between the focal length of the first lens group and the focal length of the second lens group is defined. When the focal length of the second lens group is f2, it is preferable that the following conditional expression is satisfied.
−8.00 <f1 / f2 <−3.00 (6)

  By satisfying conditional expression (6), the movement of the second lens unit accompanying zooming is reduced while satisfactorily correcting axial chromatic aberration, and the total lens length is shortened while achieving high magnification. If the upper limit of conditional expression (6) is exceeded, the focal length of the second lens group becomes relatively short, which is advantageous for downsizing, but aberration fluctuations accompanying zooming increase. If the lower limit of conditional expression (6) is not reached, the focal length of the second lens group becomes relatively long, so the amount of movement of the second lens group by zooming increases, the entire system becomes larger, and it is difficult to reduce the size and weight. It becomes.

More preferably, the numerical range of conditional expression (6) is set as follows.
−7.30 <f1 / f2 <−4.00 (6a)

As a further aspect of the zoom lens of the present invention, the partial dispersion ratio of the optical material used in the second lens group is defined. When the average values of Abbe number and partial dispersion ratio of the positive lens constituting the second lens group are ν2p and θ2p, respectively, and the average values of Abbe number and partial dispersion ratio of the negative lens are ν2n and θ2n, respectively, It is preferable to satisfy.
−2.50 × 10 ⁻³ <(θ2p−θ2n) / (ν2p−ν2n)
<−0.50 × 10 ⁻³ (7)

Here, the Abbe number and the partial dispersion ratio of the material of the optical element (lens) used in the present invention are as follows. The refractive indexes of the Fraunhofer g-line (435.8 nm), F-line (486.1 nm), d-line (587.6 nm), and C-line (656.3 nm) are Ng, NF, Nd, and NC, respectively. Then, the partial dispersion ratio θgF regarding the Abbe number νd, g-line and F-line is as follows.
νd = (Nd−1) / (NF-NC) (B)
θgF = (Ng−NF) / (NF−NC) (C)

  Existing optical materials have a partial dispersion ratio θgF in a narrow range with respect to the Abbe number νd. Further, the partial dispersion ratio θgF is larger as the Abbe number νd is smaller, and the refractive index tends to be lower as the Abbe number νd is larger.

Conditional expression (7) defines that the amount of chromatic aberration of magnification in the second lens is reduced. If the upper limit condition of the conditional expression (7) is not satisfied, it is advantageous for correcting the secondary spectrum of lateral chromatic aberration, but the refractive index of the negative lens constituting the second lens group becomes low, and the radius of curvature of the negative lens becomes small. Become. As a result, higher-order aberrations such as field curvature and coma increase, and it becomes difficult to achieve good optical performance. If the lower limit condition of conditional expression (7) is not satisfied, the secondary spectrum of chromatic aberration of magnification increases and it becomes difficult to correct chromatic aberration well. More preferably, the numerical range of conditional expression (7) is set as follows.
−2.0 × 10 ⁻³ <(θ2p−θ2n) / (ν2p−ν2n)
<−0.80 × 10 ⁻³ (7a)

As a further aspect of the zoom lens of the present invention, the partial dispersion ratio of the optical material used in the first lens group is defined. When the Abbe number and the partial dispersion ratio of the positive lens constituting the first lens group are ν1p and θ1p, respectively, and the Abbe number and the partial dispersion ratio of the negative lens are ν1n and θ1n, respectively.
−8.00 × 10 ⁻⁴ <(θ1p−θ1n) / (ν1p−ν1n)
<-1.50 × 10 ⁻⁴ (8)
Meet.

  Conditional expression (8) is defined in order to achieve correction of axial chromatic aberration at the telephoto end and high optical performance.

Exceeding the upper limit of conditional expression (8) is advantageous for correcting the secondary spectrum of longitudinal chromatic aberration at the telephoto end, but the refractive index of the positive lens constituting the second lens group is lowered, and the second lens group is constructed. The radius of curvature of the positive lens is small. As a result, higher order aberrations of spherical aberration at the telephoto end increase, making it difficult to achieve good optical performance. If the lower limit of conditional expression (8) is not reached, the secondary spectrum of axial chromatic aberration at the telephoto end increases, and it becomes difficult to satisfactorily correct the chromatic aberration at the telephoto end. The numerical range of conditional expression (8) is more preferably set as follows.
−6.5 × 10 ⁻⁴ <(θ1p−θ1n) / (ν1p−ν1n)
<-2.00 × 10 ^-4 (8a)

  In the following, with respect to a specific configuration of the zoom lens of the present invention, a lens configuration of an example and a numerical example corresponding thereto will be described.

  FIG. 1 is a lens cross-sectional view when focusing on an object at infinity at the wide angle end (short focal length end) of Numerical Embodiment 1 as Embodiment 1 of the zoom lens according to the present invention. FIGS. 2A and 2B are aberration diagrams at (A) a wide angle end, (B) a zoom position at a focal length of 400 mm, and (C) a telephoto end in an infinite focus state. In each lens cross-sectional view, the left is the subject (object) side (front), and the right is the image side (rear). U1 is a first lens group having a fixed positive refractive power. The first lens unit U1 includes subunits of an eleventh sub lens unit U11 having a positive refractive power and a twelfth sub lens unit U12 having a positive refractive power in order from the object side to the image side. Focus adjustment is performed by moving the twelfth sub lens unit U12 having positive refractive power in the optical axis direction. U2 is a second lens group having a negative refractive power that moves during zooming, and performs zooming from the wide-angle end to the telephoto end by moving the optical axis toward the image plane side. U3 is a third lens group that moves during zooming, and moves on the optical axis from the wide-angle end to the telephoto end. U4 is a fixed lens group (rear lens group), and is a fourth lens group (relay lens group) having a positive refractive power. The fourth lens unit includes subunits of a forty-first sub lens unit U41 having a positive refractive power and a forty second sub lens unit U42 having a positive refractive power in order from the object side to the image side. A fixed aperture stop SP is disposed between the forty second sub lens unit U42. A focal length conversion converter (extender) or the like may be mounted in the fourth lens unit U4. IP is an image plane and corresponds to an imaging plane such as a solid-state imaging device or a film plane.

  In each aberration diagram, the straight line and the two-dot chain line in the spherical aberration are the e-line and the g-line, respectively. A solid line and an alternate long and short dash line in astigmatism are a sagittal image plane (ΔS) and a meridional image plane (ΔM), respectively, and a two-dot chain line in lateral chromatic aberration is a g line. Astigmatism and lateral chromatic aberration indicate the amount of aberration when the light ray passing through the center of the light beam at the stop position is the principal ray. ω is the paraxial half angle of view, and Fno is the F number. In the longitudinal aberration diagram, spherical aberration is 0.5 mm, astigmatism is 0.5 mm, distortion is 5%, and lateral chromatic aberration is 0.05 mm. In each of the following embodiments, the wide-angle end and the telephoto end are zooming positions when the second lens group is positioned at both ends of a range in which the second lens unit can move on the optical axis. The explanation regarding these lens cross-sectional views and aberration diagrams is the same in the following examples unless otherwise noted.

The first to fourth lens units in Numerical Example 1 as Example 1 will be described. The first lens unit U1 includes an eleventh sub lens unit U11 corresponding to the first lens surface to the eighth lens surface and a twelfth sub lens unit U12 corresponding to the ninth lens surface to the twelfth lens surface in Numerical Example 1. It is composed of subunits. The eleventh sub-lens group U11 having positive refractive power includes a positive lens, a negative lens, a positive lens, and a negative lens in order from the object side to the image side. The twelfth sub-lens group U12 having positive refractive power is composed of two positive lenses, and focus adjustment is performed by moving the twelfth sub-lens group in the optical axis direction. The second lens unit U2 corresponds to the thirteenth to twenty-first lens surfaces in Numerical Example 1, and in order from the object side to the image side, a negative lens, a cemented positive lens in which a negative lens and a positive lens are bonded, a negative lens It consists of a lens and a positive lens. The third lens unit U3 corresponds to the twenty-second lens surface to the twenty-fourth lens surface in Numerical Example 1, and includes a cemented negative lens in which a negative lens and a positive lens are sequentially bonded from the object side to the image side. The fourth lens unit U4 includes subunits U41 corresponding to the 25th to 28th lens surfaces and U42 corresponding to the 30th to 45th lens surfaces in Numerical Example 1. U41 is composed of two lenses. U42 includes a cemented negative lens, a positive lens, a cemented negative lens, a positive lens, a cemented positive lens, and a cemented negative lens in order from the object side. Aspheric surfaces are used for the 13th and 26th surfaces. The aspherical surface of the thirteenth surface corrects fluctuations due to zooming of the field curvature and spherical aberrations on the telephoto side. The aspheric surface of the twenty-sixth surface suppresses zoom fluctuation of spherical aberration on the wide angle side and field angle fluctuation of coma aberration.

  Table 1 shows values corresponding to the conditional expressions of this example. This numerical example satisfies all the conditional expressions and achieves good optical performance. In addition, the wide-angle end focal length is 50 mm, the zoom ratio is 18 times, the wide-angle end Fno is 4.5, and the telephoto end Fno is 7.0, super telephoto, high magnification, large aperture ratio, focal length and half angle of view. The maximum image height obtained by the product of 15.7 mm is 15.7 mm, and the zoom lens corresponding to the large format sensor is miniaturized.

  The first to fourth lens groups in Numerical Example 2 as Example 2 of the zoom lens according to the present invention will be described.

  FIG. 3 is a lens cross-sectional view at the wide-angle end of the zoom lens of Example 2 in an infinite focus state. 4A and 4B are longitudinal aberration diagrams of the zoom lens of Example 2 at an infinite focus state at (A) a wide angle end, (B) a focal length of 500 mm, and (C) a telephoto end.

In Numerical Example 2, the first lens unit U1 includes an eleventh sub lens unit U11 corresponding to the first lens surface to the eighth lens surface, and a twelfth sub lens unit U12 corresponding to the ninth lens surface to the twelfth lens surface. It is composed of subunits. The eleventh sub-lens group U11 having positive refractive power includes a positive lens, a negative lens, a positive lens, and a negative lens in order from the object side to the image side. The twelfth sub-lens group U12 having positive refractive power is composed of two positive lenses, and focus adjustment is performed by moving the twelfth sub- lens group in the optical axis direction. The second lens unit U2 corresponds to the thirteenth lens surface to the nineteenth lens surface in Numerical Example 2, and in order from the object side to the image side, a negative lens, a cemented positive lens in which a negative lens and a positive lens are bonded, a negative lens It consists of a lens. The third lens unit U3 corresponds to the twentieth lens surface to the twenty-second lens surface in Numerical Example 2, and includes a cemented negative lens in which a negative lens and a positive lens are sequentially bonded from the object side to the image side. The fourth lens unit U4 includes a forty-first sub lens unit U41 corresponding to the twenty-third lens surface to the twenty-ninth lens surface and a forty-second sub lens unit U42 corresponding to the thirty-first lens surface to the forty-second lens surface in Numerical Example 2. It is composed of subunits. The forty-first sub lens unit U41 includes two positive lenses in order from the object side, and a cemented negative lens in which a positive lens and a negative lens are bonded together. The forty-second sub lens unit U42 includes, in order from the object side, a positive lens, a cemented negative lens, a negative lens, a cemented negative lens, and a positive lens. Aspheric surfaces are used for the 13th and 24th surfaces. The aspherical surface of the thirteenth surface corrects fluctuations due to zooming of the field curvature and spherical aberrations on the telephoto side. The aspherical surface of the 24th surface suppresses zoom fluctuations of spherical aberration on the wide angle side and field angle fluctuations of coma aberration.

  Table 1 shows values corresponding to the conditional expressions of this example. This numerical example satisfies all the conditional expressions and achieves good optical performance. In addition, the focal length is 50 mm at the wide angle end, the zoom ratio is 24 times, the Fno at the wide angle end is 4.5, the telephoto end Fno is 10.0, super telephoto, high magnification, large aperture ratio, and the maximum image height is 14. Although the zoom lens is 8 mm and is compatible with large format sensors, it has achieved miniaturization.

  The first to fourth lens groups in Numerical Example 3 as Example 3 of the zoom lens according to the present invention will be described.

  FIG. 5 is a lens cross-sectional view at the wide-angle end of the zoom lens according to the third exemplary embodiment at the infinity focus state. 6A and 6B are longitudinal aberration diagrams of the zoom lens of Example 3 at an infinite focus state at (A) a wide angle end, (B) a focal length of 180 mm, and (C) a telephoto end.

In Numerical Example 3, the first lens unit U1 includes an eleventh sub lens unit U11 corresponding to the first lens surface to the seventh lens surface, and a twelfth sub lens unit U12 corresponding to the eighth lens surface to the eleventh lens surface. It is composed of subunits. The eleventh sub-lens group U11 having positive refractive power includes a positive lens, a cemented positive lens in which a negative lens and a positive lens are cemented, and a negative lens in order from the object side to the image side. The twelfth sub-lens group U12 having positive refractive power is composed of two positive lenses, and focus adjustment is performed by moving the twelfth sub-lens group in the optical axis direction. The second lens unit U2 corresponds to the twelfth lens surface to the twentieth lens surface in Numerical Example 3, and in order from the object side to the image side, a negative lens, a cemented positive lens in which a negative lens and a positive lens are bonded, a negative lens It consists of a lens and a positive lens. The third lens unit U3 corresponds to the 21st lens surface to the 23rd lens surface in Numerical Example 3, and includes a cemented negative lens in which a negative lens and a positive lens are sequentially bonded from the object side to the image side. The fourth lens unit U4 corresponds to the 25th to 43rd lens surfaces in Numerical Example 3. U4 includes a positive lens, a cemented positive lens, a positive lens, two cemented negative lenses, a positive lens, a negative lens, and a positive lens in order from the object side to the image side. Aspheric surfaces are used for the 12th and 26th surfaces. The aspherical surface of the twelfth surface corrects the variation in curvature of field due to zoom and the variation in spherical aberration on the telephoto side. The aspheric surface of the twenty-sixth surface suppresses zoom fluctuation of spherical aberration on the wide angle side and field angle fluctuation of coma aberration.

  Table 1 shows values corresponding to the conditional expressions of this example. This numerical example satisfies all the conditional expressions and achieves good optical performance. In addition, the wide-angle end focal length is 45 mm, the zoom ratio is 10 times, the wide-angle end Fno is 4.0, and the telephoto end Fno is 5.6, which is super telephoto, high magnification, large aperture ratio, and maximum image height is 15. Although the zoom lens is 5 mm and corresponds to a large format sensor, it has achieved miniaturization.

  The first to fifth lens groups in Numerical Example 4 as Example 4 of the zoom lens according to the present invention will be described.

  FIG. 7 is a lens cross-sectional view at the wide-angle end of the zoom lens of Example 4 in an infinite focus state. FIG. 8 is a longitudinal aberration diagram of the zoom lens of Example 4 at an infinite focus state at (A) a wide angle end, (B) a focal length of 450 mm, and (C) a telephoto end.

In Numerical Example 4, the first lens unit U1 includes an eleventh sub lens unit U11 corresponding to the first lens surface to the eighth lens surface, and a twelfth sub lens unit U12 corresponding to the ninth lens surface to the twelfth lens surface. It is composed of subunits. The eleventh sub lens unit U11 having a positive refractive power includes a positive lens, a negative lens, a positive lens, and a negative lens in order from the object side. The twelfth sub-lens group U12 having positive refractive power is composed of two positive lenses, and focus adjustment is performed by moving the twelfth sub-lens group U12 in the axial direction having optical refracting power. The second lens unit U2 corresponds to the thirteenth lens surface to the twenty-third lens surface in Numerical Example 4, and in order from the object side to the image side, a negative lens, a cemented positive lens in which a positive lens and a negative lens are bonded, a negative lens It consists of a lens, a positive lens, and a negative lens. The third lens unit U3 corresponds to the 24th lens surface to the 28th lens surface in Numerical Example 4, and includes a cemented positive lens and a positive lens in which a positive lens and a negative lens are sequentially bonded from the object side to the image side. ing. The fourth lens unit U4 corresponds to the 29th to 33rd lens surfaces in Numerical Example 4, and is composed of a positive lens, a cemented positive lens in which a negative lens and a positive lens are bonded together in order from the object side. The fifth lens unit U5 corresponds to the 35th to 48th lens surfaces in Numerical Example 4, and in order from the object side to the image side, a negative lens, a positive lens, a negative lens, a positive lens, a cemented positive lens, and a cemented lens It consists of a negative lens. The aspherical surface is used for the 26th surface and suppresses zoom fluctuations of spherical aberration on the wide angle side and field angle fluctuations of coma aberration.

  Table 1 shows values corresponding to the conditional expressions of this example. This numerical example satisfies all the conditional expressions and achieves good optical performance. In addition, the wide-angle end focal length is 45 mm, the zoom ratio is 20 times, the wide-angle end Fno is 4.5, the telephoto end Fno is 6.5, super telephoto, high magnification, large aperture ratio, and the maximum image height is 14. Although the zoom lens is 8 mm and is compatible with large format sensors, it has achieved miniaturization.

(Imaging device)
Next, an image pickup apparatus using each of the zoom lenses described above as an image pickup optical system will be described. FIG. 9 is a schematic diagram of a main part of an image pickup apparatus (television camera system) using the zoom lens of each embodiment as a photographing optical system. In FIG. 9, reference numeral 101 denotes any one of the zoom lenses according to the first to fourth embodiments.

  Reference numeral 124 denotes a camera. The zoom lens 101 can be attached to and detached from the camera 124. An imaging apparatus 125 is configured by attaching the zoom lens 101 to the camera 124. The zoom lens 101 includes a first lens group 114, a zooming unit 115 that moves during zooming, and an imaging lens group 116. SP is an aperture stop. The lens group 116 fixed during zooming has a variable magnification optical system IE that can be inserted and removed from the optical path.

  The zoom unit 115 includes a drive mechanism for driving in the optical axis direction. Reference numerals 117 and 118 denote driving means such as a motor for electrically driving the zooming unit 115 and the aperture stop SP. By adding a driving mechanism, focusing can be performed by moving the whole lens group 114, 115, 116 or a part of each lens group in the optical axis direction. Reference numerals 119 and 120 denote detectors such as an encoder, a potentiometer, or a photosensor for detecting the position on the optical axis of each lens group in the zoom unit 115 and the aperture diameter of the aperture stop SP. The driving locus of each lens group in the zoom unit 115 may be either a mechanical locus such as a helicoid or a cam, or an electrical locus such as an ultrasonic motor. In the camera 124, 109 is a glass block corresponding to an optical filter or a color separation prism in the camera 124, and 110 is a solid that photoelectrically converts an optical image such as a CCD sensor or a CMOS sensor that receives a subject image formed by the zoom lens 101. An imaging element (photoelectric conversion element). Reference numerals 111 and 122 denote CPUs that control various types of driving of the camera 124 and the zoom lens body 101. Thus, by applying the zoom lens of the present invention to a television camera, an imaging device having high optical performance is realized.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

  Next, numerical examples 1 to 4 corresponding to the first to fourth embodiments of the present invention will be described. In each numerical example, i indicates the order of the surfaces from the object side, ri is the radius of curvature of the i-th surface from the object side, di is the i-th distance from the i-th surface from the object side, ndi and vdi, θgfi is the refractive index, Abbe number, and partial dispersion ratio of the i-th optical member. The focal length, F number, and angle of view represent values when focusing on an object at infinity. BF is a value obtained by converting the distance from the final surface of the lens to the image plane in air.

The aspherical shape is expressed by the following formula, where x is the coordinate in the optical axis direction, y is the coordinate in the direction perpendicular to the optical axis, R is the reference radius of curvature, k is the conic constant, and An is the nth-order aspherical coefficient. It is represented by However, “ex” means “× 10 ^−x ”. A lens surface having an aspherical surface is marked with * on the left side of the surface number in each table.
x = (y ² / r) / {1+ (1−k × y ² / r ² ) ^0.5 } + A4 × y ⁴ + A6 × y ⁶ + A8 × y ⁸ + A10 × y ¹⁰ + A12 × y ¹²

Table 1 shows the correspondence between each embodiment and each conditional expression described above.

(Numerical example 1)
Unit mm

Surface data Surface number rd nd vd θgF Effective diameter Focal length
1 164.54198 17.02128 1.487490 70.23 0.5300 128.571 313.627
2 -2190.49132 1.00000 1.000000 127.748
3 163.40559 3.40000 1.729157 54.68 0.5444 121.685 -413.894
4 105.23588 5.74496 1.000000 116.266
5 118.29851 22.47999 1.433870 95.10 0.5373 115.912 211.723
6 -391.74363 1.50000 1.000000 114.674
7 -311.03637 3.20000 1.729157 54.68 0.5444 114.361 -162.188
8 192.99022 17.06673 1.000000 110.421
9 154.70242 17.13122 1.433870 95.10 0.5373 110.824 258.715
10 -398.94815 0.20000 1.000000 110.169
11 138.85079 7.13187 1.433870 95.10 0.5373 103.924 788.934
12 229.58667 (variable) 1.000000 102.373

13 * 10889.24382 1.20000 1.772499 49.60 0.5521 31.612 -38.571
14 29.85572 5.86578 1.000000 28.819
15 -158.06465 1.00000 1.618000 63.33 0.5441 28.491 -42.804
16 31.99078 7.27954 1.720467 34.70 0.5834 28.180 31.994
17 -76.45010 3.05713 1.000000 28.164
18 -36.03783 1.00000 1.618000 63.33 0.5441 28.039 -53.837
19 460.54582 0.20000 1.000000 29.129
20 77.61472 2.84519 1.548141 45.79 0.5685 29.814 153.760
21 913.44529 (variable) 1.000000 30.057

22 -74.28603 1.00000 1.729157 54.68 0.5444 38.265 -70.334
23 168.94128 3.37550 1.846660 23.78 0.6205 39.859 174.819
24 -1285.45589 (variable) 1.000000 40.470

25 78.88308 8.43195 1.593490 67.00 0.5361 45.059 66.808
26 * -77.09230 1.00000 1.000000 45.248
27 50.04199 8.78266 1.595220 67.74 0.5442 43.822 62.753
28 -139.55383 3.00000 1.000000 42.888
29 0.00000 3.00000 1.000000 38.132
30 -139.46830 4.62298 1.438750 94.93 0.5343 36.278 149.353
31 -45.11036 1.20000 2.003300 28.27 0.5980 34.999 -30.099
32 94.96028 3.46019 1.000000 34.196
33 43.24218 9.03822 1.567322 42.80 0.5730 34.827 46.936
34 -64.97317 4.21679 1.000000 34.071
35 -367.83887 1.20000 2.001000 29.13 0.5997 29.285 -18.300
36 19.47519 8.01664 1.846660 23.78 0.6205 27.053 24.679
37 204.74268 43.19216 1.000000 26.456
38 47.06859 3.59028 1.487490 70.23 0.5300 21.605 76.226
39 -174.89753 7.38514 1.000000 21.379
40 -29.97651 1.00000 1.882997 40.76 0.5667 20.006 -15.430
41 25.64141 7.28780 1.717362 29.50 0.6048 21.063 17.553
42 -22.13650 2.00000 1.000000 21.773
43 -17.57471 1.00000 1.953750 32.32 0.5898 21.482 -26.173
44 -60.00000 8.53547 1.517417 52.43 0.5564 23.577 48.526
45 -18.62134 BF 1.000000 26.369
Image plane ∞

Aspherical data 13th surface
K = 9.77458e + 004 A 4 = 2.20189e-006 A 6 = 2.88707e-011 A 8 = 2.09078e-012 A10 = -1.14265e-013 A12 = 9.17677e-016 A14 = -3.08089e-018 A16 = 3.85985 e-021

26th page
K = -9.05930e-001 A 4 = 7.04555e-007 A 6 = 2.55835e-010 A 8 = -9.15718e-013 A10 = 2.78952e-015 A12 = -2.67183e-018 A14 = -1.00580e-021 A16 = 2.50307e-024

Various data Zoom ratio 18.00
Wide angle Medium Telephoto focal length 50.00 400.00 900.00
F number 4.50 4.50 7.00
Half angle of view 17.59 2.27 1.01
Image height 15.85 15.85 15.85
Total lens length 450.92 450.92 450.92
BF 45.92 45.92 45.92

d12 10.00 120.50 137.50
d21 137.35 7.78 13.34
d24 4.99 24.06 1.50
d45 45.92 45.92 45.92

Entrance pupil position 173.69 1202.69 2262.98
Exit pupil position -118.20 -118.20 -118.20
Front principal position 208.46 627.79 -1772.42
Rear principal point position -4.08 -354.08 -854.08

Zoom lens group data group Start surface Focal length Lens configuration length Front principal point position Rear principal point position
1 1 225.00 95.88 36.28 -45.00
2 13 -33.00 22.45 2.61 -13.60
3 22 -118.37 4.38 -0.24 -2.64
4 25 53.57 129.96 -4.67 -134.68

(Numerical example 2)
Unit mm

Surface data

Surface number rd nd vd θgF Effective diameter Focal length
1 163.52796 17.52677 1.496999 81.54 0.5374 121.931 265.856
2 -673.88220 1.00000 1.000000 120.523
3 135.03738 3.70000 1.772499 49.60 0.5521 111.442 -528.006
4 100.35493 4.58990 1.000000 106.756
5 108.78616 16.31248 1.433870 95.10 0.5373 105.998 261.508
6 2381.64315 4.34869 1.000000 104.445
7 -382.04680 3.20000 1.772499 49.60 0.5521 104.301 -159.307
8 183.50128 13.20363 1.000000 100.762
9 157.15620 10.85868 1.496999 81.54 0.5374 100.533 311.348
10 -12135.28995 0.20000 1.000000 99.953
11 252.22314 7.96434 1.496999 81.54 0.5374 98.133 445.272
12 -1829.62885 (variable) 1.000000 97.210

13 * -476.80680 1.20000 1.729157 54.68 0.5444 38.718 -42.539
14 33.36583 4.07612 1.000000 34.750
15 163.34864 1.00000 1.618000 63.33 0.5441 34.716 -47.723
16 25.00305 10.15149 1.720467 34.70 0.5834 33.071 30.091
17 -142.53929 5.31348 1.000000 32.043
18 -34.77696 1.00000 1.696797 55.53 0.5433 29.670 -57.145
19 -269.96392 (variable) 1.000000 29.605

20 -70.40750 1.00000 1.729157 54.68 0.5444 31.238 -64.049
21 141.35971 2.95353 1.846660 23.78 0.6205 32.349 161.138
22 -5387.41703 (variable) 1.000000 32.879

23 608.61658 3.67957 1.516330 64.14 0.5352 49.349 306.160
24 * -214.17660 0.20000 1.000000 49.934
25 61.90583 11.98059 1.496999 81.54 0.5374 52.669 74.263
26 -86.14368 0.49956 1.000000 52.517
27 92.72322 10.44842 1.438750 94.93 0.5343 48.892 92.175
28 -69.56630 1.50000 2.001000 29.13 0.5997 47.433 -47.854
29 159.60176 5.05908 1.000000 46.549
30 0.00000 2.00000 1.000000 46.736
31 61.25142 8.18905 1.688931 31.07 0.6003 47.112 67.089
32 -183.67019 19.20874 1.000000 46.507
33 -64.34334 1.20000 2.001000 29.13 0.5997 32.742 -24.825
34 41.40723 7.29247 1.761821 26.52 0.6135 32.308 34.151
35 -66.20876 53.12461 1.000000 32.389
36 -50.54071 1.50000 2.001000 29.13 0.5997 20.337 -75.398
37 -152.77839 8.68424 1.000000 20.793
38 87.15253 5.67633 1.761821 26.52 0.6135 23.578 26.448
39 -25.76129 1.00000 2.001000 29.13 0.5997 23.654 -20.499
40 107.04594 1.41893 1.000000 24.363
41 64.34057 4.19455 1.672700 32.10 0.5988 25.505 56.285
42 -91.20360 BF 1.000000 25.818
Image plane ∞

Aspherical data 13th surface
K = 0.00000e + 000 A 4 = 3.52166e-006 A 6 = -9.04425e-010 A 8 = -4.02105e-014 A10 = 2.11684e-015 A12 = -4.10826e-019

24th page
K = -8.40684e-001 A 4 = 5.82961e-007 A 6 = 1.12421e-010 A 8 = 2.39096e-013 A10 = -2.88892e-016 A12 = 2.42509e-019

Various data Zoom ratio 24.00
Wide angle Intermediate Telephoto focal length 50.00 500.00 1200.00
F number 4.50 4.49 10.00
Half angle of view 16.49 1.70 0.71
Image height 14.80 14.80 14.80
Total lens length 465.00 465.00 465.00
BF 55.00 55.00 55.00

d12 6.31 109.89 122.42
d19 114.62 3.35 28.63
d22 32.62 40.31 2.50
d42 55.00 55.00 55.00

Entrance pupil position 168.58 1476.41 3303.63
Exit pupil position -101.85 -101.85 -101.85
Front principal point 202.64 382.51 -4677.24
Rear principal point position 5.00 -445.00 -1145.00

Zoom lens group data group Start surface Focal length Lens configuration length Front principal point position Rear principal point position
1 1 208.00 82.90 24.79 -44.72
2 13 -33.00 22.74 6.49 -8.60
3 20 -106.77 3.95 -0.09 -2.26
4 23 57.71 146.86 -15.60 -128.59

(Numerical Example 3)
Unit mm

Surface data Surface number rd nd vd θgF Effective diameter Focal length
1 218.94302 6.65813 1.516330 64.14 0.5352 93.000 529.651
2 1070.66547 0.50206 1.000000 92.017
3 161.02005 3.23908 1.772499 49.60 0.5521 88.980 -256.862
4 88.29585 16.31030 1.433870 95.10 0.5373 84.717 160.333
5 -313.23472 1.00000 1.000000 83.571
6 -243.00079 2.59126 1.772499 49.60 0.5521 83.421 -240.887
7 814.81381 18.09624 1.000000 81.637
8 145.63900 9.17696 1.433870 95.10 0.5373 75.541 241.718
9 -370.84555 0.12147 1.000000 75.156
10 208.55454 5.69268 1.595220 67.74 0.5442 73.381 480.783
11 753.97372 (variable) 1.000000 72.244

12 * 187.64079 1.20000 1.754998 52.32 0.5476 36.767 -45.763
13 29.20963 6.47175 1.000000 32.965
14 -99.41626 1.20000 1.595220 67.74 0.5442 32.965 -46.046
15 38.19502 7.06175 1.720467 34.70 0.5834 32.710 39.996
16 -111.29401 2.02088 1.000000 32.475
17 -44.71072 1.20000 1.595220 67.74 0.5442 32.404 -62.827
18 235.92999 0.20000 1.000000 32.633
19 65.38496 3.62872 1.613397 44.30 0.5633 32.911 149.413
20 220.39947 (variable) 1.000000 32.698

21 -74.85518 1.20000 1.816000 46.62 0.5568 33.306 -59.919
22 144.10760 3.16986 1.846660 23.78 0.6205 34.625 126.896
23 -434.67238 (variable) 1.000000 35.172

24 0.00000 (variable) 1.000000 37.252

25 183.30520 5.47405 1.729157 54.68 0.5444 38.532 77.013
26 * -80.43620 0.15000 1.000000 38.956
27 37.58747 8.79605 1.438750 94.93 0.5343 39.025 70.608
28 -165.97844 1.20000 2.003300 28.27 0.5980 38.240 -94.218
29 224.71940 2.00000 1.000000 37.679
30 36.13538 7.12795 1.595220 67.74 0.5442 36.482 60.561
31 31 120.11909 12.94012 1.000000 35.298
32 0.00000 0.00000 1.000000 1000.000
33 0.00000 0.00000 1.000000 1000.000
34 -819.60927 0.90000 1.882997 40.76 0.5667 23.533 -20.663
35 18.78213 6.84827 1.496999 81.54 0.5374 21.610 27.995
36 -47.70406 0.88534 1.000000 21.415
37 -59.01640 5.74977 1.720467 34.70 0.5834 21.210 30.706
38 -16.83295 0.90000 1.754998 52.32 0.5476 21.357 -20.274
39 181.84438 1.22273 1.000000 21.760
40 -135.16710 2.87717 1.720467 34.70 0.5834 21.866 96.856
41 -46.64245 4.61435 1.000000 22.267
42 -23.18456 1.50000 1.800999 34.97 0.5863 22.258 -112.449
43 -32.04793 32.06714 1.000000 23.273
44 450.56283 4.04025 1.613397 44.30 0.5633 31.295 131.694
45 -98.73303 BF 1.000000 31.585
Image plane ∞

Aspheric data 12th surface
K = 3.16458e + 001 A 4 = -4.96905e-008 A 6 = -5.97045e-010 A 8 = -3.67230e-013 A10 = 8.65917e-016 A12 = -1.31114e-018

26th page
K = -9.86309e-001 A 4 = 4.01809e-007 A 6 = 3.60603e-010 A 8 = -1.00121e-012 A10 = 2.22276e-015 A12 = -1.58775e-018

Various data Zoom ratio 10.00
Wide angle Medium Telephoto focal length 45.00 180.00 450.00
F number 4.00 4.00 5.60
Half angle of view 19.01 4.92 1.97
Image height 15.50 15.50 15.50
Total lens length 346.76 346.76 346.76
BF 50.01 50.01 50.01

d11 1.00 73.58 98.23
d20 100.53 13.54 5.44
d23 3.70 18.10 1.57
d24 1.48 1.48 1.48
d43 50.01 50.01 50.01

Entrance pupil position 104.81 409.26 732.51
Exit pupil position -135.04 -135.04 -135.04
Front principal point position 138.87 414.18 88.21
Rear principal point position 5.01 -129.99 -399.99

Zoom lens group data group Start surface Focal length Lens configuration length Front principal point position Rear principal point position
1 1 165.00 63.39 33.93 -18.44
2 12 -35.00 22.98 3.06 -13.43
3 21 -115.00 4.37 -0.55 -2.94
4 24 ∞ 0.00 0.00 -0.00
5 25 56.78 99.29 10.15 -120.41

(Numerical example 4)
Unit mm

Surface data

Surface number rd nd vd θgF Effective diameter Focal length
1 203.26365 16.18658 1.516330 64.14 0.5352 140.696 372.538
2 -3744.46544 0.62000 1.000000 139.897
3 255.25309 4.00000 1.816000 46.62 0.5568 135.379 -310.743
4 126.62793 6.26000 1.000000 129.259
5 131.51692 26.20130 1.433870 95.10 0.5373 129.558 222.054
6 -341.67157 2.68000 1.000000 128.657
7 -272.42401 4.00000 1.754998 52.32 0.5476 127.917 -236.037
8 525.43544 16.75612 1.000000 126.047
9 233.96987 16.69392 1.433870 95.10 0.5373 125.391 324.664
10 -348.50969 0.15000 1.000000 124.921
11 196.59903 7.84025 1.593490 67.00 0.5361 118.800 567.240
12 463.22667 (variable) 1.000000 117.622

13 546.75468 1.80000 1.816000 46.62 0.5568 45.593 -53.964
14 40.88435 1.87376 1.000000 41.270
15 48.59907 9.26002 1.720467 34.70 0.5834 41.086 40.979
16 -70.41276 1.50000 1.595220 67.74 0.5442 40.183 -62.568
17 80.28215 3.39986 1.000000 36.202
18 -122.91019 1.50000 1.595220 67.74 0.5442 36.207 -78.325
19 75.88208 0.10000 1.000000 34.743
20 47.09744 3.45252 1.720467 34.70 0.5834 34.469 127.709
21 92.85223 5.00000 1.000000 33.706
22 -80.81558 1.40000 1.595220 67.74 0.5442 32.829 -84.129
23 133.73522 (variable) 1.000000 32.263

24 181.90523 5.00678 1.618000 63.33 0.5441 44.487 120.769
25 -126.03225 1.50000 1.834000 37.16 0.5775 44.664 -150.468
26 * -61694.41637 0.20000 1.000000 45.153
27 129.65297 6.18478 1.496999 81.54 0.5374 45.754 125.846
28 -119.59571 (variable) 1.000000 45.875

29 530.91679 3.86135 1.487490 70.23 0.5300 44.802 261.151
30 -167.81269 0.20000 1.000000 44.620
31 69.55929 1.50000 1.720467 34.70 0.5834 43.193 -134.913
32 40.29090 6.99815 1.496999 81.54 0.5374 41.536 85.522
33 692.21392 (variable) 1.000000 41.036

34 0.00000 10.51965 1.000000 28.815
35 -289.48532 1.40000 1.882997 40.76 0.5667 24.060 -62.443
36 68.75741 0.15000 1.000000 23.527
37 34.74080 3.50000 1.805181 25.42 0.6161 23.445 51.153
38 201.94538 1.83777 1.000000 22.811
39 1111.73620 1.50000 1.910820 35.25 0.5824 21.930 -45.497
40 40.18353 33.00000 1.000000 21.089
41 192.67363 5.00000 1.496999 81.54 0.5374 27.562 101.165
42 -67.71277 1.05263 1.000000 27.884
43 483.75276 1.50000 1.882997 40.76 0.5667 27.744 -42.339
44 34.84033 7.00000 1.603420 38.03 0.5835 27.520 37.797
45 -62.13777 1.13156 1.000000 27.746
46 -115.11309 6.00000 1.517417 52.43 0.5564 27.485 112.026
47 -39.35715 1.50000 1.882997 40.76 0.5667 27.448 -71.019
48 -106.54261 BF 1.000000 27.865
Image plane ∞

Aspheric data 26th surface
K = -6.77646e + 004 A 4 = 3.14453e-007 A 6 = -7.70633e-012 A 8 = 6.69043e-014 A10 = -9.36787e-017 A12 = 5.05543e-020

Various data Zoom ratio 20.00
Wide angle Medium Telephoto focal length 45.00 450.00 900.00
F number 4.50 4.50 6.50
Half angle of view 18.21 1.88 0.94
Image height 14.80 14.80 14.80
Total lens length 496.96 496.96 496.96
BF 70.00 70.00 70.00

d12 3.60 117.04 129.76
d23 163.25 44.12 3.00
d28 27.04 7.83 40.44
d33 1.85 26.75 22.55
d48 70.00 70.00 70.00

Entrance pupil position 176.91 1448.68 3058.95
Exit pupil position -91.64 -91.64 -91.64
Front principal point position 209.38 645.87 -1052.08
Rear principal point position 25.00 -380.01 -830.00

Zoom lens group data group Start surface Focal length Lens configuration length Front principal point position Rear principal point position
1 1 225.00 101.39 49.33 -34.73
2 13 -34.75 29.29 12.67 -7.06
3 24 105.00 12.89 4.69 -3.67
4 29 125.00 12.56 1.29 -7.01
5 34 -203.63 75.09 -40.82 -142.69

U1 1st lens group U2 2nd lens group U11 11th sub lens group U12 12th sub lens group

Claims (9)

In order from the object side to the image side, a first lens group having a positive refractive power that does not move for zooming, a second lens group having a negative refractive power that moves during zooming, and a lens that moves during zooming of at least one group. The zoom lens has a lens group followed by a rear lens group. During zooming, the distance between adjacent lens groups changes, and the first lens group includes an eleventh sub-lens group that does not move for focusing, and a focusing lens group. A zoom lens having a twelfth sub-lens group having positive refractive power that moves,
The eleventh sub-lens group includes a negative lens and a positive lens, the focal length of the first lens group is f1, and the rear main of the eleventh sub-lens group from the most image side lens surface of the eleventh sub-lens group. The distance on the optical axis to the point position is OK11, the focal length of the zoom lens at the telephoto end is ft, and the rear principal point of the first lens group from the lens surface closest to the image side of the first lens group When the distance on the optical axis to the position is OK1 ,
-25.00 <OK11 / f1 <-0. 8 0
2.00 <ft / f1 <7.00
−0.30 <OK1 / f1 ≦ −0.11
A zoom lens characterized by satisfying the following conditions:
However, the direction from the object side to the image side is a positive direction. When the average value of Abbe numbers of the positive lenses constituting the eleventh sub lens group is νd11p and the average value of Abbe numbers of the negative lenses constituting the eleventh sub lens group is νd11n,
20.00 <νd11p−νd11n <45.00
The zoom lens according to claim 1 , wherein the following condition is satisfied. When the average value of the Abbe number of the lenses constituting the twelfth sub lens group is νd12,
70.00 <νd12 <100.00
The zoom lens according to claim 1 or 2, characterized by satisfying the following condition. The eleventh the most object side of the lens is the positive lens group of sub lenses, zoom lens according to any one of claims 1 to 3, wherein the most image side of the lens is a negative lens. The eleventh sub-lens group, a positive lens in order from the object side to the image side, a negative lens, a positive lens, a zoom according to any one of claims 1 to 4, characterized in that it is composed of a negative lens lens. When the focal length of the second lens group is f2,
−8.00 <f1 / f2 <−3.00
The zoom lens according to any one of claims 1 to 5, characterized by satisfying the following condition. The average values of Abbe number and partial dispersion ratio of the positive lens constituting the second lens group are ν2p and θ2p, respectively, and the Abbe number and partial dispersion ratio of the negative lens constituting the second lens group are respectively ν2n, When θ2n is set,
−2.50 × 10 ⁻³ <(θ2p−θ2n) / (ν2p−ν2n)
<−0.50 × 10 ⁻³
The zoom lens according to any one of claims 1 to 6 and satisfies the.
However, when the partial dispersion ratio θ is Ng as the refractive index at the g-line, NF as the refractive index at the F-line, Nd as the refractive index at the d-line, and NC as the refractive index at the C-line,
θ = (Ng−NF) / (NF−NC)
It is represented by The Abbe number and the partial dispersion ratio of the positive lens constituting the first lens group are average values ν1p and θ1p, respectively. The Abbe number of the negative lens constituting the first lens group and the average value of the partial dispersion ratio are ν1n, respectively. When θ1n is set,
−8.00 × 10 ⁻⁴ <(θ1p−θ1n) / (ν1p−ν1n)
<-1.50 × 10 ⁻⁴
The zoom lens according to any one of claims 1 to 7, characterized in that meet. The zoom lens according to any one of claims 1 to 8 ,
An image pickup apparatus comprising an image pickup device that photoelectrically converts an optical image formed by the zoom lens.

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