JP6910842B2 - Zoom lens and imaging device with it - Google Patents

Description

The present invention relates to a zoom lens and an image pickup device having the same, and is particularly suitable for a television camera for broadcasting, a movie camera, a digital still camera, a camera for silver halide photography, and the like.

In recent years, there has been a demand for a zoom lens having a wide angle of view, a high magnification ratio, and high optical performance in an imaging device such as a television camera, a movie camera, and a photographic camera. In particular, an imaging device such as a CCD or CMOS used in a television / movie camera as a professional moving image shooting system has a substantially uniform resolution in the entire imaging range. Therefore, a zoom lens using this is required to have a substantially uniform resolution from the center of the screen to the periphery of the screen. In addition, there is a demand for smaller size and lighter weight for shooting modes that emphasize mobility and operability.

On the other hand, if a wide-angle lens having a short focal length at the wide-angle end is used, a wide range can be photographed and the perspective can be emphasized. Users who want to take advantage of this shooting effect are highly demanding wide-angle, high-magnification ratio, compact, lightweight, and high-performance wide-angle zoom lenses.

As a wide-angle zoom lens, a negative lead type zoom lens in which a lens group having a negative refractive power is arranged on the most object side and is composed of four or more lens groups as a whole is known. For example, in Patent Document 1, the magnification ratio is about 1.2, the angle of view at the wide-angle end is about 100 ° to 110 °, and the negative first lens group, the positive second lens group, and the positive lens group are in order from the object side. A zoom lens having a third lens group and a rear group is disclosed. The first lens group is fixed at the time of magnification change, and at least the second lens group and the third lens group move at the time of magnification change. Further, in Patent Document 2, the magnification ratio is about 1.2 and the angle of view at the wide-angle end is about 50 °, and the negative first lens group, the positive second lens group, and the positive third lens are in order from the object side. A zoom lens composed of a group, a negative fourth lens group, and a positive fifth lens group is disclosed.

Japanese Unexamined Patent Publication No. 2008-304765 Japanese Unexamined Patent Publication No. 2004-133338

However, the zoom lenses disclosed in Patent Documents 1 and 2 are disadvantageous in terms of the refractive power and lens configuration of each lens group for achieving both a wider angle and a larger diameter, and the lens diameter is increased as the angle is increased. It becomes difficult to suppress the increase in the total length due to the increase in size and diameter. In particular, when the angle of view at the wide-angle end exceeds 100 degrees, the tendency of increasing the lens diameter and the amount of movement of the variable magnification group becomes remarkable.

The present invention is, for example, wide field angle, a large aperture, and an object thereof is to provide a compact, lightweight, advantageous zoom lens in terms of transient Ru high optical performance in the entire zoom range.

In order to achieve the above object, the zoom lens of the present invention is a first lens group having a negative refractive force that does not move for scaling in order from the object side to the image side, and positive refraction that moves at the time of scaling. a second lens group having a force having a rear group that includes two or more lens groups, the spacing between adjacent lens groups is configured to vary during zooming both, the most object side of the rear group The arranged third lens group has a positive refractive force and moves at the time of scaling, and the first lens group has a negative lens on the most object side, and has a positive lens and two or more negative lenses. a final lens group which is disposed closest to the image side of the rear group includes a positive lens and a negative lens having an aperture stop from the image side second lens group, the first lens group The focal distance is f1, the focal distance at the wide-angle end of the zoom lens is fw, the distance from the aperture aperture at the wide-angle end to the most image-side surface of the final lens group is d, and the most image of the final lens group at the wide-angle end. When the distance from the side surface to the image surface is BF,
-5.0 <f1 / fw <-1.5
0.10 <BF / d <0.45
It is characterized in that it satisfies the conditional expression.

According to the present invention, for example, wide field angle, a large aperture, compact, lightweight, points in an advantageous zoom lens passes Ru high optical performance in the entire zoom range.

Numerical value Cross-sectional view of the lens at infinity focusing at the wide-angle end of Example 1 Numerical Aberration diagram at infinity focusing at the wide-angle end (a), middle zoom (b), and telephoto end (c) of Example 1. Numerical value Cross-sectional view of the lens at infinity focusing at the wide-angle end of Example 2 Aberration diagram at infinity focusing at the wide-angle end (a), middle zoom (b), and telephoto end (c) of Numerical Example 2 Numerical value Cross-sectional view of the lens at infinity focusing at the wide-angle end of Example 3 Aberration diagram at infinity focusing at the wide-angle end (a), middle zoom (b), and telephoto end (c) of Numerical Example 3 Numerical value Cross-sectional view of the lens at infinity focusing at the wide-angle end of Example 4 Aberration diagram at infinity focusing at the wide-angle end (a), middle zoom (b), and telephoto end (c) of Numerical Example 4 Numerical value Cross-sectional view of the lens at infinity focusing at the wide-angle end of Example 5 Numerical Aberration diagram at infinity focusing at the wide-angle end (a), middle zoom (b), and telephoto end (c) of Example 5. Numerical value Cross-sectional view of the lens at infinity focusing at the wide-angle end of Example 6 Aberration diagram at infinity focusing at the wide-angle end (a), middle zoom (b), and telephoto end (c) of Numerical Example 6 Numerical values Optical path diagram at the wide-angle end (a), middle zoom (b), and telephoto end (c) of the zoom lens of Example 1. Schematic diagram of the main part of the image pickup apparatus of the present invention

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
First, the features of the zoom lens of the present invention will be described along with each conditional expression. The zoom lens of the present invention has a wide angle of view, a large diameter, a small size and light weight, and in order to achieve high optical performance over the entire zoom range, the ratio of the focal length of the first lens group to the focal length at the wide angle end and the aperture aperture are used. It is characterized by defining the ratio of the distance to the final surface of the final lens group and the back focus.

The zoom lens of the present invention and the image pickup apparatus having the same include a first lens group having a negative refractive force that does not move for scaling in order from the object side to the image side, and a positive refractive force that moves at the time of scaling. It has a second lens group having a rear group and a rear group including two or more lens groups including a lens group that moves at the time of magnification change, and constitutes the first lens group, the second lens group, and the rear group at the time of magnification change. In a zoom lens configured so that the distance between adjacent lens groups changes, the first lens group has a negative lens on the most object side, and the first lens group has a positive lens and 2 The final lens group having more than one negative lens and arranged on the image side most in the rear group has a positive lens and a negative lens, and has an aperture aperture on the image side of the second lens group. The focal distance of the first lens group is f1, the focal distance of the wide-angle end of the zoom lens is fw, the distance from the aperture aperture at the wide-angle end to the most image-side surface of the final lens group is d, and the said at the wide-angle end. When the distance from the image plane to the image plane of the final lens group is BF,
-5.0 <f1 / fw <-1.5 ... (1)
0.10 <BF / d <0.45 ... (2)
Meet.

In the present invention, the first lens group having a fixed negative refractive power at the time of scaling and the second lens group having a positive refractive power moving at the time of scaling are provided, and the focal length of the first lens group is appropriately set. The optical action of the lens will be described.

FIG. 13 shows an optical path diagram at the wide-angle end (a), the middle zoom end (b), and the telephoto end (c) of the first embodiment of the present invention. L1 to L5 represent the first lens group to the fifth lens group, respectively. As can be seen from the optical path diagram of FIG. 13, in the embodiment of the present invention, the second lens group is separated from the first lens group at the wide-angle end, and the second lens group is separated from the first lens group at the telephoto end. Is the trajectory that approaches. At the wide-angle end, the first lens group having a negative refractive power and the second lens group having a positive refractive power are arranged apart from each other, so that the position of the entrance pupil can be arranged on the object side. Therefore, the configuration is advantageous for both wide-angle lens and compact size and light weight.

Further, as can be seen from the optical path diagram at the telephoto end of FIG. 13, the lens diameter of the second lens group is determined by the axial marginal light beam at the telephoto end. The lens diameter of the group increases. Therefore, by increasing the focal length of the first lens group, it is possible to reduce the angle of the divergent light beam incident on the second lens group, so that it is possible to suppress an increase in the lens diameter of the second lens group. It will be possible. On the other hand, when the focal length of the first lens group is lengthened, the retro ratio becomes low, so that the back focus of the zoom lens tends to be short. As described above, in the present invention, by appropriately setting the focal length of the first lens group, it is possible to achieve a large aperture, a small size and a light weight, and a back focus.

Further, the first lens group is characterized by having two or more negative lenses and one or more positive lenses. The first lens group has a negative refractive power, but in order to widen the angle, a negative lens is placed on the most object side, and at least two lenses are used to suppress chromatic aberration generated in the first lens group. The above negative lens and one or more positive lenses are required. In addition, since off-axis rays pass through a position away from the optical axis in the final lens group, one or more positive lenses and one or more negative lenses are required to satisfactorily correct chromatic aberration of magnification, especially at the wide-angle end. You will need it.

Further, by satisfying the above-mentioned equations (1) and (2), it is possible to effectively achieve high optical performance over the entire zoom range with a wide angle of view, a large aperture, a small size and light weight.

Equation (1) defines the ratio of the focal length of the first lens group to the focal length at the wide-angle end. By satisfying the equation (1), both wide-angle zoom lens and compact size and light weight are achieved. If the upper limit condition of the equation (1) is not satisfied, the refractive power of the first lens group becomes weak and the retro ratio becomes low, so that it becomes difficult to secure the back focus of the zoom lens. Further, since the object point of the second lens group is moved away, the amount of movement of the second lens group due to the magnification change increases, and it becomes difficult to reduce the size and weight of the zoom lens. If the lower limit condition of the equation (1) is not satisfied, the refractive power of the first lens group is strong, and it becomes difficult to correct the aberration fluctuation due to magnification change and the aberration fluctuation due to focusing. More preferably, the equation (1) is set as follows.
-4.0 <f1 / fw <-1.7 ... (1a)

Equation (2) defines the ratio of the distance from the aperture stop at the wide-angle end to the most image-side surface of the final lens group and the distance from the most image-side surface of the final lens group at the wide-angle end to the image plane. ing. By satisfying equation (2), an appropriate back focus is ensured. If the upper limit condition of Eq. (2) is not satisfied, it is necessary to secure a long back focus, and therefore it is necessary to increase the refractive power of the first lens group. Therefore, the lens diameter of the second lens group becomes large. , It becomes difficult to reduce the size and weight of the zoom lens. If the lower limit condition of the equation (2) is not satisfied, the back focus is too short, and it becomes difficult to arrange an optical filter such as a low-pass filter between the zoom lens and the image pickup device. More preferably, the equation (2) is set as follows.
0.15 <BF / d <0.42 ... (2a)

As a further aspect of the zoom lens of the present invention, the first lens group includes a lens group that moves during focusing. By configuring the focusing with a part of the first lens group, the amount of focusing can be kept constant regardless of the magnification change, which is advantageous for simplification of the drive mechanism and miniaturization of the focus lens group. The configuration is as follows.

A further aspect of the zoom lens of the present invention is that the third lens group, which is the lens group on the most object side of the rear group, has a positive refractive power and moves at the time of magnification change. By moving the second lens group and the third lens group at the same time at the time of scaling, it is possible to effectively suppress aberration fluctuations due to scaling, particularly spherical aberration and curvature of field in the middle of zooming.

As a further aspect of the zoom lens of the present invention, when the focal length of the second lens group is f2 and the focal length of the third lens group is f3,
-1.0 <f1 x (f2 + f3) / (f2 x f3) <-0.3 ... (3)
Meet. Equation (f2 × f3) / (f2 + f3) in Eq. (3) is a numerical value corresponding to the combined focal length of the second lens group and the third lens group, and Eq. (3) is the focal length of the first lens group. , The ratio of the combined focal length of the second lens group and the third lens group is specified. By satisfying the equation (3), the correction of the aberration fluctuation of the zoom lens is achieved. If the condition of the upper limit of the equation (3) is not satisfied, the refractive power of the first lens group becomes strong, and it becomes difficult to correct the aberration fluctuation due to magnification change and the aberration fluctuation due to focusing. If the lower limit condition of the equation (3) is not satisfied, the combined focal length of the second lens group and the third lens group becomes short, and it becomes difficult to correct the aberration fluctuation due to the scaling. More preferably, the equation (3) is set as follows.
-0.9 <f1 x (f2 + f3) / (f2 x f3) <-0.4 ... (3a)

As a further aspect of the zoom lens of the present invention, the ratio of the focal lengths of the second lens group and the third lens group is defined. When the focal lengths of the second lens group and the third lens group are f2 and f3,
0.4 <f2 / f3 <2.0 ... (4)
Meet. By satisfying the equation (4), spherical aberration, coma aberration, and curvature of field due to scaling can be satisfactorily corrected. If the upper limit of Eq. (4) is not satisfied, the refractive power of the second lens group becomes relatively weak, and the height of the light beam incident on the third lens group becomes high, thereby suppressing fluctuations in spherical aberration due to scaling. Becomes difficult. If the lower limit of Eq. (4) is not satisfied, the refractive power of the third lens group becomes relatively weak, and the effect of correcting spherical aberration and curvature of field due to changing the distance from the second lens group is effective. Since it becomes small, it becomes difficult to suppress the aberration fluctuation due to the scaling. More preferably, the equation (4) is set as follows.
0.5 <f2 / f3 <1.5 ... (4a)

A further aspect of the zoom lens of the present invention is that the first lens group has a first negative lens and a second negative lens in order from the object side. By having two negative lenses in succession from the object side in the first lens group, the principal point on the object side of the first lens group can be set on the object side, which is effective in achieving both wide angle and small size and light weight. It becomes possible to achieve the target.

Further, the image pickup apparatus of the present invention is characterized by having a zoom lens of each embodiment and a solid-state image pickup device having a predetermined effective image pickup range for receiving an image formed by the zoom lens.

Hereinafter, a specific configuration of the zoom lens of the present invention will be described with reference to the characteristics of the lens configurations of Numerical Examples 1 to 6 corresponding to Examples 1 to 6.

FIG. 1 is a cross-sectional view of a zoom lens according to a first embodiment (numerical value embodiment 1) of the present invention when the lens is in focus at infinity at a wide-angle end. In FIG. 2, (a) is a wide-angle end of Numerical Example 1, (b) is a focal length of 17.16 mm of Numerical Example 1, and (c) is a longitudinal aberration diagram of a telephoto end of Numerical Example 1. .. Each aberration diagram is a longitudinal aberration diagram when the lens is in focus at infinity. Further, the value of the focal length is a value when the numerical embodiment described later is expressed in mm. This is the same for all of the following numerical examples.

In FIG. 1, the first lens group L1 having a negative refractive power for focusing is provided in order from the object side. Further, when scaling from the wide-angle end to the telephoto end, there is a second lens group L2 with a positive refractive power that moves toward the object side and a third lens group L3 with a positive refractive power that moves toward the object side. is doing. Further, the fourth lens group L4 having a negative refractive power that moves non-linearly on the optical axis in conjunction with the movement of the second lens group L2 and the third lens group L3 to correct the image plane fluctuation due to the magnification change. have. Further, it has a fifth lens group L5 having a positive refractive power that does not move due to scaling. In this embodiment, the second lens group L2, the third lens group L3, and the fourth lens group L4 constitute a variable magnification system. The SP is an aperture diaphragm and is arranged between the third lens group L3 and the fourth lens group L4. Further, the aperture diaphragm is immovable in the optical axis direction at the time of scaling, and by changing the aperture diameter according to the scaling, it is possible to maintain a predetermined F number. In this embodiment, the rear group corresponds to the third lens group L3 to the fifth lens group L5. I is an image plane, and when used as an image pickup optical system for a broadcasting TV camera, a video camera, or a digital still camera, a solid-state image sensor (photoelectric conversion element) that receives an image formed by a zoom lens and performs photoelectric conversion. ) Etc. corresponds to the imaging surface. When used as an imaging optical system for a film camera, it corresponds to the film surface to which the image formed by the zoom lens is exposed.

In the longitudinal aberration diagram, the straight line and the alternate long and short dash line in spherical aberration are e-line and g-line, respectively. The dotted line and the solid line in astigmatism are the meridional image plane and the sagittal image plane, respectively, and the alternate long and short dash line in the chromatic aberration of magnification is the g line. ω is a half angle of view and Fno is an F number. In the longitudinal aberration diagram, spherical aberration is 0.4 mm, astigmatism is 0.4 mm, distortion is 5%, and chromatic aberration of magnification is 0.1 mm. In each of the following embodiments, the wide-angle end and the telephoto end refer to the zoom positions when the second lens group L2 for scaling is located at both ends of a range that can be moved on the optical axis with respect to the mechanism.

Next, the first lens group L1 in this embodiment will be described. The first lens group L1 corresponds to the first to tenth surfaces. The first lens group L1 is from the eleventh lens group L11 having a negative refractive power that does not move during focusing, and the twelfth lens group L12 having a positive refractive power that moves toward the image side when focusing from the infinity side to the nearest side. It is composed. The second lens group L2 corresponds to the 11th to 14th planes, the 3rd lens group L3 corresponds to the 15th to 17th planes, and the 4th lens group L4 corresponds to the 19th to 23rd planes. There is. The fifth lens group L5 corresponds to the 24th to 31st planes. The first lens group L1 includes a convex lens and a concave lens, and is composed of five lenses as a whole. The second lens group L2 includes a convex lens and a concave lens and has two lenses as a whole, the third lens group L3 includes a convex lens and a concave lens and has two lenses as a whole, and the fourth lens group L4 includes a convex lens and a concave lens. It consists of three lenses as a whole. Further, the fifth lens group L5 includes a convex lens and a concave lens, and is composed of five lenses as a whole.

Numerical value Example 1 corresponding to the said Example 1 will be described. Numerical value In all numerical examples, not limited to Example 1, i indicates the order of surfaces (optical surfaces) from the object side, ri is the radius of curvature of the i-th surface from the object side, and di is the i-th from the object side. The distance between the second surface and the i + 1th surface (on the optical axis) is shown. Further, ndi and νdi represent the refractive index, Abbe number, and partial dispersion ratio of the medium (optical member) between the i-th plane and the i + 1-th plane, and BF represents the back focus in terms of air. .. The aspherical shape has an X-axis in the optical axis direction, an H-axis in the direction perpendicular to the optical axis, and a positive light traveling direction. When each has an aspherical coefficient, it is expressed by the following equation. Further, "e-Z" means " ^x10 -Z".

Table 1 shows the values corresponding to each conditional expression in this embodiment. This embodiment satisfies the equations (1) to (4), and has a wide angle of view (angle of view) of 114.2 ° at the wide-angle end, a magnification ratio of 1.5, and an F number of 1.4. Achieved both caliber. In addition, we have achieved a zoom lens that achieves both high optical performance and compactness and weight reduction that satisfactorily correct various aberrations over the entire zoom range. However, the zoom lens of the present invention is indispensable to satisfy the equations (1) and (2), but may not satisfy the equations (3) and (4). However, even better effects can be achieved if at least one of the equations (3) and (4) is satisfied. This also applies to other examples.

FIG. 14 is a schematic view of an image pickup apparatus (television camera system) using the zoom lens of each embodiment as a photographing optical system. In FIG. 12, 101 is a zoom lens according to any one of Examples 1 to 5. 124 is a camera. The zoom lens 101 is removable from the camera 124. Reference numeral 125 denotes an imaging device configured by attaching a zoom lens 101 to a camera 124. The zoom lens 101 has a first lens group F, a variable magnification portion LZ, and a fourth lens group R for imaging. The first lens group F includes a focusing lens group. The variable magnification LZ includes a second lens group that moves on the optical axis for zooming, a third lens group, and a fourth lens group that moves on the optical axis to correct image plane fluctuations due to zooming. There is. SP is an aperture stop. 114 and 115 are drive mechanisms such as a helicoid and a cam that drive the first lens group F and the variable magnification portion LZ in the optical axis direction, respectively. Reference numerals 116 to 118 are motors (driving means) for electrically driving the drive mechanisms 114 and 115 and the aperture stop SP. Reference numerals 119 to 121 are detectors such as an encoder, a potentiometer, or a photo sensor for detecting the position of the first lens group F or the variable magnification portion LZ on the optical axis and the aperture diameter of the aperture aperture SP. In the camera 124, 109 is a glass block corresponding to an optical filter and a color separation optical system in the camera 124, and 110 is a solid-state image sensor (photoelectric conversion) such as a CCD sensor or a CMOS sensor that receives a subject image formed by the zoom lens 101. Element). Further, 111 and 122 are CPUs that control various drives 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 image pickup device having high optical performance is realized.

FIG. 3 is a cross-sectional view of the zoom lens according to the second embodiment (numerical value embodiment 2) of the present invention when the lens is focused at infinity at the wide-angle end. In FIG. 4, (a) is a wide-angle end of Numerical Example 2, (b) is a focal length of 18.34 mm of Numerical Example 2, and (c) is a longitudinal aberration diagram of the telephoto end of Numerical Example 2. .. Each aberration diagram is a longitudinal aberration diagram when the lens is in focus at infinity.

In FIG. 3, the first lens group L1 having a negative refractive power for focusing is provided in order from the object side. Further, when scaling from the wide-angle end to the telephoto end, there is a second lens group L2 with a positive refractive power that moves toward the object side and a third lens group L3 with a positive refractive power that moves toward the object side. is doing. Further, the fourth lens group L4 having a negative refractive power that moves non-linearly on the optical axis in conjunction with the movement of the second lens group L2 and the third lens group L3 to correct the image plane fluctuation due to the magnification change. have. Further, it has a fifth lens group L5 having a positive refractive power that does not move due to scaling. In this embodiment, the second lens group L2, the third lens group L3, and the fourth lens group L4 constitute a variable magnification system. The SP is an aperture diaphragm and is arranged between the third lens group L3 and the fourth lens group L4. Further, the aperture diaphragm is immovable in the optical axis direction at the time of scaling, and by changing the aperture diameter according to the scaling, it is possible to maintain a predetermined F number. In this embodiment, the rear group corresponds to the third lens group L3 to the fifth lens group L5.

Next, the first lens group L1 in this embodiment will be described. The first lens group L1 corresponds to the first to eighth surfaces. The first lens group L1 is from the eleventh lens group L11 having a negative refractive power that does not move during focusing, and the twelfth lens group L12 having a positive refractive power that moves toward the image side when focusing from the infinity side to the nearest side. It is composed. The second lens group L2 corresponds to the 9th to 12th planes, the 3rd lens group L3 corresponds to the 13th to 15th planes, and the 4th lens group L4 corresponds to the 17th to 21st planes. There is. The fifth lens group L5 corresponds to the 22nd to 29th planes. The first lens group L1 includes a convex lens and a concave lens, and is composed of four lenses as a whole. The second lens group L2 includes a convex lens and a concave lens and has two lenses as a whole, the third lens group L3 includes a convex lens and a concave lens and has two lenses as a whole, and the fourth lens group L4 includes a convex lens and a concave lens. It consists of three lenses as a whole. Further, the fifth lens group L5 includes a convex lens and a concave lens, and is composed of five lenses as a whole.

Table 1 shows the values corresponding to each conditional expression in this embodiment. This embodiment satisfies the equations (1) to (4), and has a wide angle of view (angle of view) of 114.2 ° at the wide-angle end, a magnification ratio of 1.71, and an F number of 1.8. Achieved both caliber. In addition, we have achieved a zoom lens that achieves both high optical performance with good correction of various aberrations over the entire zoom range and compactness and weight reduction.

FIG. 5 is a cross-sectional view of the zoom lens according to the third embodiment (numerical value embodiment 3) of the present invention when the lens is in focus at infinity at the wide-angle end. In FIG. 6, (a) is a wide-angle end of Numerical Example 3, (b) is a focal length of 15.48 mm of Numerical Example 3, and (c) is a longitudinal aberration diagram of a telephoto end of Numerical Example 3. .. Each aberration diagram is a longitudinal aberration diagram when the lens is in focus at infinity.

In FIG. 5, the first lens group L1 having a negative refractive power for focusing is provided in order from the object side. Further, when scaling from the wide-angle end to the telephoto end, there is a second lens group L2 with a positive refractive power that moves toward the object side and a third lens group L3 with a positive refractive power that moves toward the object side. is doing. Further, the fourth lens group L4 having a negative refractive power that moves non-linearly on the optical axis in conjunction with the movement of the second lens group L2 and the third lens group L3 to correct the image plane fluctuation due to the magnification change. have. Further, it has a fifth lens group L5 having a positive refractive power that does not move due to scaling. In this embodiment, the second lens group L2, the third lens group L3, and the fourth lens group L4 constitute a variable magnification system. The SP is an aperture diaphragm and is arranged between the third lens group L3 and the fourth lens group L4. Further, the aperture diaphragm is immovable in the optical axis direction at the time of scaling, and by changing the aperture diameter according to the scaling, it is possible to maintain a predetermined F number. In this embodiment, the rear group corresponds to the third lens group L3 to the fifth lens group L5.

Next, the first lens group L1 in this embodiment will be described. The first lens group L1 corresponds to the first to twelfth surfaces. The first lens group L1 is from the eleventh lens group L11 having a negative refractive power that does not move during focusing, and the twelfth lens group L12 having a positive refractive power that moves toward the image side when focusing from the infinity side to the nearest side. It is composed. The second lens group L2 corresponds to the 13th to 15th planes, the third lens group L3 corresponds to the 16th to 20th planes, and the 4th lens group L4 corresponds to the 22nd to 26th planes. There is. The fifth lens group L5 corresponds to the 27th to 34th planes. The first lens group L1 includes a convex lens and a concave lens, and is composed of six lenses as a whole. The second lens group L2 includes a convex lens and a concave lens as a whole, two lenses, the third lens group L3 includes a convex lens and a concave lens and three lenses as a whole, and the fourth lens group L4 includes a convex lens and a concave lens. It consists of three lenses as a whole. Further, the fifth lens group L5 includes a convex lens and a concave lens, and is composed of five lenses as a whole.

Table 1 shows the values corresponding to each conditional expression in this embodiment. This embodiment satisfies the equations (1) to (4), and has a wide angle of view (angle of view) of 122.0 ° at the wide-angle end, a magnification ratio of 1.67, and an F number of 2.0. Achieved both caliber. In addition, we have achieved a zoom lens that achieves both high optical performance with good correction of various aberrations over the entire zoom range and compactness and weight reduction.

FIG. 7 is a cross-sectional view of the zoom lens according to the fourth embodiment (numerical value embodiment 4) of the present invention when the lens is in focus at infinity at the wide-angle end. In FIG. 8, (a) is a wide-angle end of Numerical Example 4, (b) is a focal length of 22.64 mm of Numerical Example 4, and (c) is a longitudinal aberration diagram of the telephoto end of Numerical Example 2. .. Each aberration diagram is a longitudinal aberration diagram when the lens is in focus at infinity.

In FIG. 7, the first lens group L1 having a negative refractive power for focusing is provided in order from the object side. Further, when the magnification is changed from the wide-angle end to the telephoto end, the second lens group L2 having a positive refractive power moving toward the object side, the third lens group L3 having a positive refractive power moving toward the object side, and the image. It has a fourth lens group L4 with a negative refractive power that moves to the side. Further, it has a fifth lens group L5 having a positive refractive power that corrects image plane fluctuations due to scaling in conjunction with the movement of the second lens group L2, the third lens group L3, and the fourth lens group. .. In this embodiment, the second lens group L2, the third lens group L3, the fourth lens group L4, and the fifth lens group L5 constitute a variable magnification system. The SP is an aperture diaphragm and is arranged between the third lens group L3 and the fourth lens group L4. Further, the aperture diaphragm is immovable in the optical axis direction at the time of scaling, and by changing the aperture diameter according to the scaling, it is possible to maintain a predetermined F number. In this embodiment, the rear group corresponds to the third lens group L3 to the fifth lens group L5.

Next, the first lens group L1 in this embodiment will be described. The first lens group L1 corresponds to the first to tenth surfaces. The first lens group L1 is from the eleventh lens group L11 having a negative refractive power that does not move during focusing, and the twelfth lens group L12 having a positive refractive power that moves toward the image side when focusing from the infinity side to the nearest side. It is composed. The second lens group L2 corresponds to the 11th to 15th planes, the 3rd lens group L3 corresponds to the 16th to 17th planes, and the 4th lens group L4 corresponds to the 19th to 21st planes. There is. The fifth lens group L5 corresponds to the 22nd to 29th planes. The first lens group L1 includes a convex lens and a concave lens, and is composed of five lenses as a whole. The second lens group L2 includes a convex lens and a concave lens and has three lenses as a whole, the third lens group L3 has one convex lens, and the fourth lens group L4 has a convex lens and a concave lens and has two lenses as a whole. It is made up. Further, the fifth lens group L5 includes a convex lens and a concave lens, and is composed of five lenses as a whole.

Table 1 shows the values corresponding to each conditional expression in this embodiment. This embodiment satisfies the equations (1) to (4), and has a wide-angle and large-diameter shooting angle of view (angle of view) of 107.0 ° at the wide-angle end, a magnification ratio of 2, and an F number of 2.8. Achieves both. In addition, we have achieved a zoom lens that achieves both high optical performance with good correction of various aberrations over the entire zoom range and compactness and weight reduction.

FIG. 9 is a cross-sectional view of the zoom lens according to the fifth embodiment (numerical value embodiment 5) of the present invention when the lens is in focus at infinity at the wide-angle end. In FIG. 10, (a) is a wide-angle end of Numerical Example 5, (b) is a focal length of 17.13 mm of Numerical Example 5, and (c) is a longitudinal aberration diagram of a telephoto end of Numerical Example 5. .. Each aberration diagram is a longitudinal aberration diagram when the lens is in focus at infinity.

In FIG. 9, the first lens group L1 having a negative refractive power for focusing is provided in order from the object side. Further, it has a second lens group L2 having a positive refractive power for scaling that moves to the object side when scaling from the wide-angle end to the telephoto end. Further, it has a third lens group L3 having a positive refractive power that moves non-linearly on the optical axis in conjunction with the movement of the second lens group L2 and corrects image plane fluctuations due to scaling. In this embodiment, the second lens group L2 and the third lens group L3 form a variable magnification system. Further, it has a fourth lens group L4 having a positive refractive power that does not move due to scaling. The SP is an aperture diaphragm and is arranged between the second lens group L2 and the third lens group L3. Further, the aperture diaphragm is immovable in the optical axis direction at the time of scaling, and by changing the aperture diameter according to the scaling, it is possible to maintain a predetermined F number. In this embodiment, the rear group corresponds to the third lens group L3 and the fourth lens group L4.

Next, the first lens group L1 in this embodiment will be described. The first lens group L1 corresponds to the first to tenth surfaces. The first lens group L1 is from the eleventh lens group L11 having a negative refractive power that does not move during focusing, and the twelfth lens group L12 having a positive refractive power that moves toward the image side when focusing from the infinity side to the nearest side. It is composed. The second lens group L2 corresponds to the 11th to 17th planes, the 3rd lens group L3 corresponds to the 19th to 21st planes, and the 4th lens group L4 corresponds to the 22nd to 29th planes. There is. The first lens group L1 includes a convex lens and a concave lens, and is composed of five lenses as a whole. The second lens group L2 includes a convex lens and a concave lens and has four lenses as a whole, the third lens group L3 includes a convex lens and a concave lens and has two lenses as a whole, and the fourth lens group L4 includes a convex lens and a concave lens. It consists of 5 lenses as a whole.

Table 1 shows the values corresponding to each conditional expression in this embodiment. This embodiment satisfies the equations (1) and (2), and has a wide angle of view (angle of view) of 114.2 ° at the wide-angle end, a magnification ratio of 1.49, and an F number of 1.8. Achieved both caliber. In addition, we have achieved a zoom lens that achieves both high optical performance with good correction of various aberrations over the entire zoom range and compactness and weight reduction.

FIG. 11 is a cross-sectional view of the zoom lens according to the sixth embodiment (numerical value embodiment 6) of the present invention when the lens is focused at infinity at the wide-angle end. In FIG. 11, (a) is a wide-angle end of Numerical Example 6, (b) is a focal length of 19.59 mm of Numerical Example 6, and (c) is a longitudinal aberration diagram of the telephoto end of Numerical Example 6. .. Each aberration diagram is a longitudinal aberration diagram when the lens is in focus at infinity.

In FIG. 11, the first lens group L1 having a negative refractive power for focusing is provided in order from the object side. Further, when scaling from the wide-angle end to the telephoto end, there is a second lens group L2 with a positive refractive power that moves toward the object side and a third lens group L3 with a positive refractive power that moves toward the object side. is doing. Further, the fourth lens group L4 having a negative refractive power that moves non-linearly on the optical axis in conjunction with the movement of the second lens group L2 and the third lens group L3 to correct the image plane fluctuation due to the magnification change. have. Further, it has a fifth lens group L5 having a positive refractive power that does not move due to scaling. In this embodiment, the second lens group L2, the third lens group L3, and the fourth lens group L4 constitute a variable magnification system. The SP is an aperture diaphragm and is arranged between the fourth lens group L4 and the fifth lens group L5. Further, the aperture diaphragm is immovable in the optical axis direction at the time of scaling. In this embodiment, the rear group corresponds to the third lens group L3 to the fifth lens group L5.

Next, the first lens group L1 in this embodiment will be described. The first lens group L1 corresponds to the first to tenth surfaces. The first lens group L1 is from the eleventh lens group L11 having a negative refractive power that does not move during focusing, and the twelfth lens group L12 having a positive refractive power that moves toward the image side when focusing from the infinity side to the nearest side. It is composed. The second lens group L2 corresponds to the 11th to 14th planes, the 3rd lens group L3 corresponds to the 15th to 17th planes, and the 4th lens group L4 corresponds to the 18th to 20th planes. There is. The fifth lens group L5 corresponds to the 22nd to 29th planes. The first lens group L1 includes a convex lens and a concave lens, and is composed of five lenses as a whole. The second lens group L2 includes a convex lens and a concave lens and has two lenses as a whole, the third lens group L3 includes a convex lens and a concave lens and has two lenses as a whole, and the fourth lens group L4 includes a convex lens and a concave lens. It consists of two lenses as a whole. Further, the fifth lens group L5 includes a convex lens and a concave lens, and is composed of five lenses as a whole.

Table 1 shows the values corresponding to each conditional expression in this embodiment. This embodiment satisfies the equations (1) to (4), and has a wide angle of view (angle of view) of 107.0 ° at the wide-angle end, a magnification ratio of 1.5, and an F number of 2.0. Achieved both caliber. In addition, we have achieved a zoom lens that achieves both high optical performance with good correction of various aberrations over the entire zoom range and compactness and weight reduction.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and modifications can be made within the scope of the gist thereof.

<Numerical Example 1>
Unit mm

Surface data Surface number i ri di ndi vdi Effective diameter
1 * -1131.690 2.70 1.59522 67.7 85.90
2 31.420 20.29 56.68
3 * 1551.909 2.00 1.76385 48.5 54.58
4 * 33.027 13.21 47.57
5 -78.000 1.50 1.43875 94.7 47.61
6 92.253 0.25 49.67
7 83.942 8.99 1.72047 34.7 50.10
8-101.185 1.44 50.25
9 -277.435 4.82 1.49700 81.5 49.36
10 -78.762 (variable) 49.15
11 53.661 1.80 1.83481 42.7 47.72
12 42.337 2.42 46.96
13 48.693 10.05 1.49700 81.5 48.50
14 -184.474 (variable) 48.66
15 130.661 1.00 2.00069 25.5 48.54
16 49.810 12.72 1.59522 67.7 47.63
17 -69.113 (variable) 47.71
18 (Aperture) ∞ (Variable) 40.56
19 -50.774 1.00 1.83481 42.7 34.79
20 154.583 5.16 1.85478 24.8 35.38
21 -144.528 0.20 35.72
22 40.497 3.50 1.72047 34.7 35.69
23 53.317 (variable) 34.77
24 37.240 5.58 1.69680 55.5 32.19
25 7770.823 0.18 32.09
26 40.086 1.00 2.00100 29.1 31.77
27 26.081 5.68 1.49700 81.5 30.53
28 96.751 8.23 30.20
29 190.651 6.31 1.43875 94.7 29.49
30 -30.564 1.00 2.00330 28.3 29.27
31 * -106.779 16.44 30.30
Image plane ∞

Aspherical data first surface
K = 0.00000e + 000 A 4 = 5.68409e-006 A 6 = -4.26817e-009 A 8 = 2.69205e-012 A10 = -9.63497e-016 A12 = 1.60310e-019

Third side
K = 0.00000e + 000 A 4 = -2.32989e-006 A 6 = -1.65965e-009 A 8 = 1.45223e-012

4th side
K = 0.00000e + 000 A 4 = 2.23324e-007 A 6 = -9.73277e-009 A 8 = 4.16561e-012

31st page
K = 0.00000e + 000 A 4 = 1.48109e-005 A 6 = 1.39561e-008

Various data Zoom ratio 1.50
Wide-angle medium telephoto focal length 14.00 17.16 20.99
F number 1.40 1.40 1.40
Half angle of view 57.09 51.58 45.87
Image height 21.64 21.64 21.64
Lens overall length 205.52 205.52 205.52
BF 16.44 16.44 16.44

d10 40.40 22.76 5.82
d14 1.44 13.41 24.34
d17 1.72 7.39 13.40
d18 7.29 11.86 23.31
d23 17.20 12.63 1.19

Entrance pupil position 28.84 29.51 30.81
Exit pupil position -54.94 -54.19 -50.81
Front principal point position 40.09 42.50 45.24
Rear principal point position 2.44 -0.72 -4.54

Zoom lens group Data group Start surface Focal length Lens configuration length Front principal point position Rear principal point position
1 1 -39.89 55.20 -1.78 -66.41
2 11 112.78 14.27 4.85 -5.43
3 15 123.11 13.72 8.53 0.04
4 19 -189.00 9.86 -1.83 -7.27
5 24 61.00 27.97 -10.66 -27.09

<Numerical Example 2>
Unit mm

Surface data Surface number i ri di ndi vdi Effective diameter
1 * -1519.138 2.70 1.59522 67.7 85.17
2 29.226 22.06 54.65
3 * -272.380 2.00 1.76385 48.5 53.21
4 * 46.303 9.80 47.62
5 -98.698 1.50 1.43875 94.7 47.61
6 97.105 6.72 48.55
7 140.761 8.80 1.83481 42.7 51.11
8-75.299 (variable) 51.22
9 48.243 1.80 1.83400 37.2 41.21
10 40.448 1.44 40.54
11 49.044 8.74 1.49700 81.5 40.78
12 -164.027 (variable) 40.85
13 248.623 1.00 2.00069 25.5 37.65
14 46.595 9.40 1.59522 67.7 37.15
15 -55.776 (variable) 37.32
16 (Aperture) ∞ (Variable) 31.42
17 -42.090 1.00 1.77250 49.6 27.85
18 50.150 4.39 1.85478 24.8 28.55
19 -289.985 0.20 28.74
20 37.692 3.00 1.58913 61.1 29.05
21 80.145 (variable) 28.71
22 45.538 4.63 1.58913 61.1 26.15
23 -198.459 3.06 25.99
24 47.509 5.32 1.49700 81.5 26.77
25 -86.918 1.00 2.00100 29.1 26.53
26 425.166 10.04 26.55
27 * 162.269 1.00 2.00330 28.3 27.26
28 35.142 6.39 1.43875 94.7 27.84
29 -102.051 17.11 29.35
Image plane ∞

Aspherical data first surface
K = 0.00000e + 000 A 4 = 5.99331e-006 A 6 = -4.25857e-009 A 8 = 2.67299e-012 A10 = -9.63497e-016 A12 = 1.60310e-019

Third side
K = 0.00000e + 000 A 4 = -3.60309e-006 A 6 = 2.72952e-009 A 8 = -8.82936e-013

4th side
K = 0.00000e + 000 A 4 = 3.04462e-007 A 6 = -1.84398e-009 A 8 = 1.73204e-012

27th page
K = 0.00000e + 000 A 4 = -1.50000e-005 A 6 = -1.61834e-008

Various data Zoom ratio 1.71
Wide-angle medium telephoto focal length 14.00 18.34 23.98
F number 1.80 1.80 1.80
Half angle of view 57.09 49.71 42.06
Image height 21.64 21.64 21.64
Lens overall length 206.22 206.22 206.22
BF 17.11 17.11 17.11

d 8 50.13 25.53 2.83
d12 1.29 22.66 34.86
d15 1.52 4.75 15.26
d16 5.87 11.32 19.11
d21 14.29 8.84 1.05

Entrance pupil position 28.85 29.93 32.42
Exit pupil position -54.97 -54.59 -53.24
Front principal point position 40.13 43.58 48.23
Rear principal point position 3.11 -1.23 -6.87

Zoom lens group Data group Start surface Focal length Lens configuration length Front principal point position Rear principal point position
1 1 -45.00 53.59 -5.68 -78.48
2 9 100.90 11.98 3.00 -5.42
3 13 160.96 10.40 10.34 4.20
4 17 -209.08 8.59 -4.70 -9.81
5 22 66.74 31.43 -6.80 -29.45

<Numerical Example 3>
Unit mm

Surface data Surface number i ri di ndi vdi Effective diameter
1 * ∞ 2.70 1.59522 67.7 86.33
2 30.535 18.11 55.60
3 * 289.493 2.00 1.76385 48.5 53.94
4 33.429 8.71 45.46
5 326.427 2.00 1.49700 81.5 45.37
6 * 39.271 5.92 44.35
7 62.343 1.80 1.76385 48.5 44.83
8 42.242 3.48 43.82
9 54.974 6.88 1.72047 34.7 44.86
10 -2125.730 2.60 44.63
11 -195.368 4.73 1.49700 81.5 44.32
12 -63.133 (variable) 44.18
13 43.554 1.80 1.80100 35.0 40.86
14 28.955 10.75 1.48749 70.2 38.65
15 -132.276 (variable) 38.04
16 136.928 1.00 1.85026 32.3 31.74
17 35.842 7.85 1.51633 64.1 31.22
18 -68.653 0.46 31.32
19 -90.895 2.71 1.58913 61.1 31.15
20 -58.589 (variable) 31.17
21 (Aperture) ∞ (Variable) 27.96
22 -45.429 1.00 1.75500 52.3 23.31
23 41.503 4.81 1.85478 24.8 24.72
24 262.380 0.20 26.27
25 42.999 3.00 1.58913 61.1 28.84
26 138.452 (variable) 29.21
27 27.988 5.65 1.69680 55.5 32.60
28 85.233 0.39 32.08
29 30.380 1.00 2.00100 29.1 31.46
30 18.798 7.73 1.49700 81.5 29.09
31 93.752 7.33 28.72
32 207.470 7.40 1.43875 94.7 27.85
33 -21.995 1.00 2.00330 28.3 27.58
34 * -55.431 14.09 29.35
Image plane ∞

Aspherical data first surface
K = 0.00000e + 000 A 4 = 5.43555e-006 A 6 = -4.14303e-009 A 8 = 2.67173e-012 A10 = -9.63497e-016 A12 = 1.60310e-019

Third side
K = 0.00000e + 000 A 4 = 1.53414e-006 A 6 = -6.01425e-009 A 8 = 2.93270e-012

Side 6
K = 0.00000e + 000 A 4 = 7.64829e-007 A 6 = -1.62389e-008 A 8 = 6.70235e-012

34th page
K = 0.00000e + 000 A 4 = 2.33583e-005 A 6 = 1.33381e-008

Various data Zoom ratio 1.67
Wide-angle medium telephoto focal length 12.00 15.48 19.98
F number 2.00 2.00 2.00
Half angle of view 60.98 54.41 47.27
Image height 21.64 21.64 21.64
Lens overall length 208.36 208.36 208.36
BF 14.09 14.09 14.09

d12 43.96 23.68 4.20
d15 1.43 21.74 34.85
d20 1.74 1.71 8.08
d21 5.25 13.32 23.15
d26 18.89 10.83 1.00

Entrance pupil position 27.40 28.19 29.81
Exit pupil position -54.98 -53.31 -49.44
Front principal point position 37.31 40.11 43.51
Rear principal point position 2.09 -1.39 -5.90

Zoom lens group Data group Start surface Focal length Lens configuration length Front principal point position Rear principal point position
1 1 -32.93 58.92 0.90 -67.94
2 13 89.42 12.55 1.77 -6.66
3 16 122.57 12.02 9.51 1.76
4 22 -130.43 9.01 -1.97 -7.24
5 27 59.42 30.49 -11.31 -29.11

<Numerical Example 4>
Unit mm

Surface data Surface number i ri di ndi vdi Effective diameter
1 * 108.830 2.50 1.59522 67.7 69.92
2 26.510 14.65 49.40
3 * 74.806 2.00 1.76385 48.5 47.83
4 28.523 11.06 40.28
5 -95.259 1.20 1.59522 67.7 39.99
6 92.755 0.16 39.31
7 47.277 4.59 1.65412 39.7 39.45
8 118.076 4.83 38.84
9 -104.459 3.97 1.49700 81.5 38.38
10 -50.015 (variable) 38.22
11 109.552 1.44 1.80610 40.9 27.60
12 30.550 6.35 1.49700 81.5 28.01
13 -130.887 0.20 28.79
14 55.530 3.60 1.59522 67.7 30.11
15 352.983 (variable) 30.19
16 -155.430 4.33 1.59522 67.7 32.61
17 -43.811 (variable) 32.91
18 (Aperture) ∞ (Variable) 29.25
19 -43.825 0.80 1.83481 42.7 23.66
20 66.625 3.41 1.85478 24.8 24.11
21 -190.845 (variable) 24.34
22 42.020 7.16 1.69680 55.5 35.37
23 -121.749 0.16 35.39
24 46.253 8.36 1.43875 94.7 34.44
25 -49.942 1.00 2.00100 29.1 33.64
26 -93.675 8.70 33.51
27 * -417.142 1.00 2.00330 28.3 28.78
28 28.690 7.90 1.43875 94.7 28.49
29 -167.074 (variable) 29.91
Image plane ∞

Aspherical data first surface
K = 0.00000e + 000 A 4 = 4.12668e-006 A 6 = -1.28702e-009 A 8 = 6.90662e-013

Third side
K = 0.00000e + 000 A 4 = -2.66548e-006 A 6 = 9.84939e-011 A 8 = 8.87587e-013

27th page
K = 0.00000e + 000 A 4 = -1.17463e-005 A 6 = -5.95569e-009 A 8 = 1.32060e-011

Various data Zoom ratio 2.00
Wide-angle medium telephoto focal length 16.00 22.64 32.00
F number 2.80 2.80 2.80
Half angle of view 53.52 43.70 34.07
Image height 21.64 21.64 21.64
Lens total length 194.29 194.29 194.29
BF 25.08 26.32 30.92

d10 32.93 17.21 5.01
d15 3.25 13.61 20.81
d17 1.73 7.09 12.09
d18 2.95 13.71 24.97
d21 28.97 16.96 1.10
d29 25.08 26.32 30.92

Entrance pupil position 28.74 29.29 30.21
Exit pupil position -66.57 -57.96 -41.41
Front principal point position 41.95 45.85 48.06
Rear principal point position 9.08 3.69 -1.07

Zoom lens group Data group Start surface Focal length Lens configuration length Front principal point position Rear principal point position
1 1 -30.04 44.96 6.60 -35.02
2 11 97.76 11.59 5.41 -2.07
3 16 100.67 4.33 3.72 1.05
4 19 -71.00 4.21 -0.74 -3.04
5 22 47.97 34.28 -13.79 -31.20

<Numerical Example 5>
Unit mm

Surface data Surface number i ri di ndi vdi Effective diameter
1 * -257.940 2.70 1.59522 67.7 87.83
2 32.767 17.94 57.97
3 * 70.169 2.00 1.76385 48.5 54.82
4 * 29.249 8.90 46.49
5 158.026 1.50 1.43875 94.7 46.05
6 51.762 3.27 44.81
7 40.163 4.92 1.72047 34.7 45.07
8 53.298 9.62 43.69
9 -70.798 4.87 1.48749 70.2 43.30
10 -40.500 (variable) 43.40
11 55.407 1.80 1.69680 55.5 34.69
12 38.375 4.07 34.49
13 46.990 5.44 1.51742 52.4 37.09
14 115.547 1.44 37.42
15 45.756 1.00 2.00100 29.1 38.85
16 34.088 11.37 1.49700 81.5 38.09
17 -76.244 (variable) 38.20
18 (Aperture) ∞ (Variable) 32.79
19 -45.719 1.00 1.77250 49.6 27.80
20 -494.807 2.91 1.85478 24.8 28.28
21 -84.749 (variable) 28.58
22 36.673 6.41 1.69680 55.5 32.48
23 -1075.313 0.21 32.45
24 36.050 1.00 2.00100 29.1 32.27
25 21.831 8.25 1.49700 81.5 30.53
26 -3033.122 10.02 30.38
27 -110.408 7.07 1.43875 94.7 29.31
28 -20.770 1.00 2.00330 28.3 29.32
29 * -47.424 18.49 31.82
Image plane ∞

Aspherical data first surface
K = 0.00000e + 000 A 4 = 6.51538e-006 A 6 = -4.46467e-009 A 8 = 2.75219e-012 A10 = -9.63497e-016 A12 = 1.60310e-019

Third side
K = 0.00000e + 000 A 4 = -1.43243e-005 A 6 = 1.00026e-008 A 8 = -2.38817e-012

4th side
K = 0.00000e + 000 A 4 = -1.29775e-005 A 6 = 6.43493e-009 A 8 = -1.36678e-013

29th page
K = 0.00000e + 000 A 4 = 1.04130e-005 A 6 = -9.06947e-009

Various data Zoom ratio 1.49
Wide-angle medium telephoto focal length 14.00 17.13 20.89
F number 1.80 1.80 1.80
Half angle of view 57.09 51.63 46.01
Image height 21.64 21.64 21.64
Lens total length 194.38 194.38 194.38
BF 18.49 18.49 18.49

d10 27.71 16.27 6.92
d17 2.30 13.73 23.08
d18 6.08 12.59 25.47
d21 21.10 14.59 1.71

Entrance pupil position 28.08 28.47 29.15
Exit pupil position -60.91 -59.65 -54.24
Front principal point position 39.61 41.85 44.03
Rear principal point position 4.49 1.36 -2.40

Zoom lens group Data group Start surface Focal length Lens configuration length Front principal point position Rear principal point position
1 1 -34.38 55.72 2.12 -56.10
2 11 69.24 25.13 12.45 -6.25
3 19 -151.45 3.91 -3.26 -5.50
4 22 50.35 33.95 -10.22 -30.00

<Numerical Example 6>
Unit mm

Surface data Surface number i ri di ndi vdi Effective diameter
1 * -297.926 2.70 1.59522 67.7 86.45
2 30.973 20.02 56.74
3 * 132.571 2.00 1.76385 48.5 54.64
4 * 31.946 12.28 47.59
5 -96.653 1.50 1.43875 94.7 47.60
6 59.355 2.90 49.30
7 70.403 8.94 1.72047 34.7 51.05
8-152.535 2.07 51.15
9 -119.266 4.30 1.49700 81.5 50.91
10 -66.451 (variable) 50.99
11 58.644 1.80 1.83481 42.7 45.96
12 41.485 1.27 44.46
13 45.734 9.97 1.49700 81.5 44.64
14 -115.188 (variable) 44.26
15 108.417 1.00 2.00069 25.5 38.68
16 46.131 10.29 1.49700 81.5 38.05
17 -51.211 (variable) 38.18
18 -49.483 1.00 1.72916 54.7 29.42
19 63.632 3.95 1.85478 24.8 29.80
20 -505.507 (variable) 29.88
21 (Aperture) ∞ 1.50 29.90
22 40.039 4.56 1.76385 48.5 29.98
23 328.677 13.69 29.32
24 39.317 1.00 2.00100 29.1 21.44
25 17.864 4.82 1.49700 81.5 20.02
26 211.556 15.04 19.43
27 49.278 7.37 1.51633 64.1 33.14
28 -121.221 1.00 1.88300 40.8 33.82
29 * 7541.940 20.15 34.34
Image plane ∞

Aspherical data first surface
K = 0.00000e + 000 A 4 = 6.58174e-006 A 6 = -4.45074e-009 A 8 = 2.73176e-012 A10 = -9.63497e-016 A12 = 1.60310e-019

Third side
K = 0.00000e + 000 A 4 = -9.75163e-006 A 6 = 6.98782e-009 A 8 = -1.80467e-012

4th side
K = 0.00000e + 000 A 4 = -8.13193e-006 A 6 = 4.21547e-009 A 8 = -1.47372e-012

29th page
K = 0.00000e + 000 A 4 = 4.50393e-006 A 6 = -8.96863e-009

Various data Zoom ratio 1.50
Wide-angle medium telephoto focal length 16.00 19.59 23.99
F number 2.00 2.00 2.00
Half angle of view 53.52 47.84 42.04
Image height 21.64 21.64 21.64
Lens overall length 209.14 209.14 209.14
BF 20.15 20.15 20.15

d10 35.82 21.07 6.85
d14 1.45 16.98 21.39
d17 4.50 12.39 24.60
d20 12.27 3.60 1.19

Entrance pupil position 28.97 29.98 31.76
Exit pupil position -49.98 -49.98 -49.98
Front principal point position 41.32 44.10 47.54
Rear principal point position 4.15 0.55 -3.85

Zoom lens group Data group Start surface Focal length Lens configuration length Front principal point position Rear principal point position
1 1 -37.14 56.71 -0.94 -65.69
2 11 107.11 13.04 4.66 -4.43
3 15 123.73 11.29 8.23 0.89
4 18 -91.22 4.95 -0.53 -3.24
5 21 57.58 48.97 10.10 -37.73

Table 1: Values corresponding to each conditional expression in each numerical example

L1: 1st lens group L2: 2nd lens group L3: 3rd lens group (rear group)
L4: 4th lens group (rear group)
L5: 5th lens group (rear group)

Claims (6)

From the object side to the image side, a first lens group having a negative refractive power that does not move for scaling, a second lens group having a positive refractive power that moves at the time of scaling, and two or more lens groups. In a zoom lens having a rear group including, and configured such that the spacing between adjacent lens groups changes upon scaling.
The third lens group arranged on the object side of the rear group has a positive refractive power and moves at the time of scaling.
The first lens group has a negative lens on the most object side, and has a positive lens and two or more negative lenses.
The final lens group which is disposed closest to the image side of the rear group includes a positive lens and a negative lens,
It has an aperture diaphragm on the image side of the second lens group.
The focal length of the first lens group is f1, the focal length of the zoom lens at the wide-angle end is fw, the distance from the aperture stop at the wide-angle end to the most image-side surface of the final lens group is d, and the wide-angle end. When the distance from the image side surface to the image surface of the final lens group in is BF,
-5.0 <f1 / fw <-1.5
0.10 <BF / d <0.45
A zoom lens characterized by satisfying the conditional expression. The zoom lens according to claim 1, wherein the first lens group includes a portion that moves during focusing. When the focal lengths of the first lens group, the second lens group, and the third lens group are f1, f2, and f3, respectively,
-1.0 <f1 x (f2 + f3) / (f2 x f3) <-0.3
The zoom lens according to claim 1 or 2 , wherein the zoom lens satisfies the conditional expression. 0 . 4 <f2 / f3 <2.0
The zoom lens according to claim 3, wherein the zoom lens satisfies the conditional expression. The zoom lens according to any one of claims 1 to 4 , wherein the first lens group has a first negative lens and a second negative lens in this order from the object side to the image side. A zoom lens according to any one of claims 1 to 5, an imaging apparatus characterized by having a solid-state imaging device for receiving an image formed by the zoom lens.

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