High-magnification zoom lens

Abstract

To provide a high-performance and small-sized optical system that has a high zoom ratio of approximately 15x zoom or more, and various aberrations are excellently corrected.SOLUTION: A high-magnification zoom lens has a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, a third lens group G3 having a positive refractive power, a fourth lens group G4 having a positive refractive power, an L-th lens group GL having a positive refractive power which is positioned closest to an image side, in order from an object side, a gap between the lens groups varies when varying from a wide angle end to a telephoto end, the third lens group G3 consists of a 3A lens group G3A with a positive refractive power and a 3B lens group G3B with a negative refractive power, image blurring correction is performed by moving the 3B lens group G3B in an approximately vertical direction to an optical axis, the fourth lens group G4 consists of a 4A lens group G4A with a positive refractive power and a 4B lens group G4B with a negative refractive power, focusing from infinity to close range is performed by moving the 4B lens group G4B in an optical axis direction from an object side to an image side, and the lens satisfies a specified conditional expression.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention is suitable as a high-magnification zoom lens with a zoom ratio of approximately 15 or more, among imaging lenses used in imaging devices such as digital cameras and video cameras. [Background technology]

[0002] In recent years, there has been a demand for zoom lenses used in imaging devices that have a high zoom ratio, high resolution, and a small overall system size. In particular, there is a demand for high-magnification zoom lenses with wider angles and telephoto capabilities so that photographing a variety of scenes can be performed without changing lenses.

[0003] Furthermore, there is a demand for a mechanism to prevent image blurring caused by vibrations of the optical system due to camera shake, particularly in the telephoto range.

[0004] Furthermore, there is a demand for quick autofocus driving. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2021-12243 [Patent Document 2] WO2021 / 131370 publication Summary of the Invention [Problem to be solved by the invention]

[0006] Patent Document 1 discloses a compact zoom lens that has a large angle of view of about 40 degrees half angle at the wide-angle end and is equipped with an image blur prevention mechanism.

[0007] However, the zoom ratio is only about 4x, and there are issues with increasing the focal length, especially at the telephoto end.

[0008] Patent Document 2 discloses a zoom lens with a focal length of about 400 mm at the telephoto end.

[0009] However, the zoom ratio is only about 4x, which poses challenges in increasing the angle of view, especially at the wide-angle end.Another issue is the overall length.

[0010] The present invention provides a high-performance, compact optical system that has a high zoom ratio of approximately 15x or more and in which various aberrations are well corrected. [Means for solving the problem]

[0011] In order to solve the above problems, the present invention provides a zoom lens having, in order from the object side, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, a third lens group G3 having positive refractive power, a fourth lens group G4 having positive refractive power, and an Lth lens group GL located closest to the image side and having positive refractive power, wherein the spacing between the lens groups changes during zooming from the wide-angle end to the telephoto end, and the third lens group G3 is a 3A lens group G3A having positive refractive power. and a 3B lens group G3B of negative refractive power, image blurring is corrected by moving the 3B lens group G3B in a direction approximately perpendicular to the optical axis, the fourth lens group G4 is composed of a 4A lens group G4A of positive refractive power and a 4B lens group G4B of negative refractive power, focusing from an infinity state to a close distance is performed by moving the 4B lens group G4B in the optical axis direction from the object side to the image side, and the high-magnification zoom lens satisfies the following conditional expression: (1) 0.25 <f1 / fT<0.66 (2) 0.35<|ff / fr|<0.80 f1: focal length of the first lens group G1 fT: focal length of the entire system at infinity at the telephoto end ff: composite focal length of the first lens group G1 and the second lens group G2 at infinity at the wide-angle end fr: composite focal length from the third lens group G3 to the L lens group GL at infinity at the wide-angle end [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a high-performance, compact optical system that has a high zoom ratio of approximately 15 times or more and in which various aberrations are well corrected. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a diagram illustrating the lens configuration at infinity at the wide-angle end of a high-magnification zoom lens according to a first embodiment of the present invention. [Figure 2] 3A and 3B are longitudinal aberration diagrams at infinity at the wide-angle end of the high-magnification zoom lens of Example 1. FIG. [Figure 3] 1 is a longitudinal aberration diagram of the high-magnification zoom lens of Example 1 at infinity at an intermediate focal length. [Figure 4] 3A and 3B are longitudinal aberration diagrams at infinity at the telephoto end of the high-magnification zoom lens of Example 1. FIG. [Figure 5] 4A and 4B are diagrams illustrating lateral aberration at infinity at the wide-angle end of the high-magnification zoom lens of Example 1. FIG. [Figure 6] 4A and 4B are diagrams illustrating lateral aberration at infinity at an intermediate focal length of the high-magnification zoom lens of Example 1. [Figure 7] 4A and 4B are diagrams illustrating lateral aberration at infinity at the telephoto end of the high-magnification zoom lens of Example 1. [Figure 8] 10A and 10B are diagrams illustrating lateral aberration when a shake angle of 0.3 degrees is corrected during image stabilization at infinity at the wide-angle end of the high-magnification zoom lens of Example 1. [Figure 9] 10A and 10B are diagrams illustrating lateral aberration when a shake angle of 0.3 degrees is corrected during image stabilization at infinity at the intermediate focal length of the high-magnification zoom lens of Example 1. FIG. [Figure 10] 10A and 10B are diagrams illustrating lateral aberration when a shake angle of 0.3 degrees is corrected during image stabilization at infinity at the telephoto end of the high-magnification zoom lens of Example 1. FIG. [Figure 11] FIG. 10 is a diagram illustrating the lens configuration at infinity at the wide-angle end of Example 2 of the high-magnification zoom lens of the present invention. [Figure 12] 10A and 10B are longitudinal aberration diagrams at infinity at the wide-angle end of the high-magnification zoom lens of Example 2. FIG. [Figure 13] FIG. 10 is a longitudinal aberration diagram of the high-magnification zoom lens of Example 2 at infinity at an intermediate focal length. [Figure 14] 10A and 10B are longitudinal aberration diagrams at infinity at the telephoto end of the high-magnification zoom lens of Example 2. FIG. [Figure 15] 10A and 10B are diagrams illustrating lateral aberration at infinity at the wide-angle end of the high-magnification zoom lens of Example 2. FIG. [Figure 16] 10A and 10B are diagrams illustrating lateral aberration at infinity at an intermediate focal length of the high-magnification zoom lens of Example 2. FIG. [Figure 17] 10A and 10B are diagrams illustrating lateral aberration at infinity at the telephoto end of the high-magnification zoom lens of Example 2. FIG. [Figure 18] 10A and 10B are diagrams illustrating lateral aberration when a shake angle of 0.3 degrees is corrected during image stabilization at infinity at the wide-angle end of the high-magnification zoom lens of Example 2. [Figure 19] FIG. 10 is a diagram showing lateral aberration when a shake angle of 0.3 degrees is corrected during image stabilization at infinity at the intermediate focal length of the high-magnification zoom lens of Example 2. [Figure 20] FIG. 10 is a diagram showing lateral aberration when a shake angle of 0.3 degrees is corrected during image stabilization at infinity at the telephoto end of the high-magnification zoom lens of Example 2. [Figure 21] FIG. 10 is a diagram illustrating the lens configuration at infinity at the wide-angle end of Example 3 of the high-magnification zoom lens of the present invention. [Figure 22] 10A and 10B are longitudinal aberration diagrams at infinity at the wide-angle end of the high-magnification zoom lens of Example 3. FIG. [Figure 23] 10A and 10B are longitudinal aberration diagrams at infinity at an intermediate focal length of the high-magnification zoom lens of Example 3. FIG. [Figure 24] 10A and 10B are longitudinal aberration diagrams at infinity at the telephoto end of the high-magnification zoom lens of Example 3. FIG. [Figure 25] 10A and 10B are diagrams illustrating lateral aberration at infinity at the wide-angle end of the high-magnification zoom lens of Example 3. [Figure 26] 10A and 10B are diagrams illustrating lateral aberration at infinity at an intermediate focal length of the high-magnification zoom lens of Example 3. [Figure 27] 10A and 10B are diagrams illustrating lateral aberration at infinity at the telephoto end of the high-magnification zoom lens of Example 3. FIG. [Figure 28] 10A and 10B are diagrams illustrating lateral aberration when a shake angle of 0.3 degrees is corrected during image stabilization at infinity at the wide-angle end of the high-magnification zoom lens of Example 3. FIG. [Figure 29] 10A and 10B are diagrams illustrating lateral aberration when a shake angle of 0.3 degrees is corrected during image stabilization at infinity at an intermediate focal length of the high-magnification zoom lens of Example 3. FIG. [Figure 30] 10A and 10B are diagrams illustrating lateral aberration when a shake angle of 0.3 degrees is corrected during image stabilization at infinity at the telephoto end of the high-magnification zoom lens of Example 3. FIG. [Figure 31] FIG. 10 is a diagram illustrating the lens configuration at infinity at the wide-angle end of Example 4 of the high-magnification zoom lens of the present invention. [Figure 32] 10A and 10B are longitudinal aberration diagrams at infinity at the wide-angle end of the high-magnification zoom lens of Example 4. FIG. [Figure 33] 10A and 10B are longitudinal aberration diagrams at infinity at an intermediate focal length of the high-magnification zoom lens of Example 4. FIG. [Figure 34] 10A and 10B are longitudinal aberration diagrams at infinity at the telephoto end of the high-magnification zoom lens of Example 4. FIG. [Figure 35] 10A and 10B are diagrams illustrating lateral aberration at infinity at the wide-angle end of the high-magnification zoom lens of Example 4. FIG. [Figure 36] 10A and 10B are diagrams illustrating lateral aberration at infinity at an intermediate focal length of the high-magnification zoom lens of Example 4. FIG. [Figure 37] 10A and 10B are diagrams illustrating lateral aberration at infinity at the telephoto end of the high-magnification zoom lens of Example 4. FIG. [Figure 38] 10A and 10B are diagrams illustrating lateral aberration when a shake angle of 0.3 degrees is corrected during image stabilization at infinity at the wide-angle end of the high-magnification zoom lens of Example 4. FIG. [Figure 39] FIG. 10 is a diagram showing lateral aberration when a shake angle of 0.3 degrees is corrected during image stabilization at infinity at the intermediate focal length of the high-magnification zoom lens of Example 4. [Figure 40] 10A and 10B are diagrams illustrating lateral aberration when a shake angle of 0.3 degrees is corrected during image stabilization at infinity at the telephoto end of the high-magnification zoom lens of Example 4. FIG. [Figure 41] FIG. 10 is a diagram illustrating the lens configuration at infinity at the wide-angle end of a high-magnification zoom lens according to a fifth embodiment of the present invention. [Figure 42] 10A and 10B are longitudinal aberration diagrams at infinity at the wide-angle end of the high-magnification zoom lens of Example 5. [Figure 43]10A and 10B are longitudinal aberration diagrams at infinity at an intermediate focal length of the high-magnification zoom lens of Example 5. [Figure 44] 10A and 10B are longitudinal aberration diagrams at infinity at the telephoto end of the high-magnification zoom lens of Example 5. [Figure 45] 10A and 10B are diagrams illustrating lateral aberration at infinity at the wide-angle end of the high-magnification zoom lens of Example 5. [Figure 46] 10A and 10B are diagrams illustrating lateral aberration at infinity at an intermediate focal length of the high-magnification zoom lens of Example 5. [Figure 47] 10A and 10B are diagrams illustrating lateral aberration at infinity at the telephoto end of the high-magnification zoom lens of Example 5. [Figure 48] 10A and 10B are diagrams illustrating lateral aberration when a shake angle of 0.3 degrees is corrected during image stabilization at infinity at the wide-angle end of the high-magnification zoom lens of Example 5. [Figure 49] 10A and 10B are diagrams illustrating lateral aberration when a shake angle of 0.3 degrees is corrected during image stabilization at infinity at an intermediate focal length of the high-magnification zoom lens of Example 5. [Figure 50] 10A and 10B are diagrams illustrating lateral aberration when a shake angle of 0.3 degrees is corrected during image stabilization at infinity at the telephoto end of the high-magnification zoom lens of Example 5. DETAILED DESCRIPTION OF THE INVENTION

[0014] Examples of the high-magnification zoom lens according to the present invention will be described in detail below. Note that the following description of the examples is an example of the high-magnification zoom lens according to the present invention, and the present invention is not limited to these examples within the scope of the gist of the present invention.

[0015] As can be seen from the lens construction diagrams shown in FIGS. 1, 11, 21, 31, and 41, the high-magnification zoom lens of the present invention comprises, in order from the object side, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, a third lens group G3 having positive refractive power, a fourth lens group G4 having positive refractive power, and an L-th lens group GL having positive refractive power and located closest to the image side. When zooming from the wide-angle end to the telephoto end, the spacing between the lens groups changes, and the third lens group G A high-magnification zoom lens 3 is characterized in that it comprises a 3A lens group G3A with positive refractive power and a 3B lens group G3B with negative refractive power, and image blurring is corrected by moving the 3B lens group G3B in a direction approximately perpendicular to the optical axis, and the fourth lens group G4 comprises a 4A lens group G4A with positive refractive power and a 4B lens group G4B with negative refractive power, and focusing from infinity to a close distance is performed by moving the 4B lens group G4B in the optical axis direction from the object side to the image side, and satisfies the following conditional expression: (1) 0.25 <f1 / fT<0.66 (2) 0.35<|ff / fr|<0.80 f1: focal length of the first lens group G1 fT: focal length of the entire system at infinity at the telephoto end ff: composite focal length of the first lens group G1 and the second lens group G2 at infinity at the wide-angle end fr: composite focal length from the third lens group G3 to the L lens group GL at infinity at the wide-angle end

[0016] As an optical system for achieving a high zoom ratio, a zoom lens is generally known that includes, in order from the object side, a first lens group with positive refractive power, a second lens group with negative refractive power, a third lens group with positive refractive power, and multiple rear groups, with a group for focusing within the rear group. Among these, for example, Patent Document 1 discloses a zoom lens that has a subgroup for image blur correction within the third lens group, thereby reducing the size of the optical system.

[0017] Furthermore, in general, in a zoom lens that is composed of, in order from the object side, a first lens group with positive refractive power, a second lens group with negative refractive power, a third lens group with positive refractive power, and multiple rear groups, the on-axis light ray in the third lens group passes through a high position throughout the entire zoom range, causing large spherical aberrations and coma aberrations in the third lens group. Therefore, the high-magnification zoom lens of the present invention is configured with a third lens group G3 with positive refractive power and a fourth lens group G4 with positive refractive power, the spacing of which varies during magnification variation, thereby making it possible to keep spherical aberrations and coma aberrations small throughout the entire zoom range, and to keep aberrations small throughout the entire optical system.

[0018] Conditional expression (1) defines the ratio between the focal length of the first lens group G1 and the focal length of the entire system at infinity at the telephoto end.

[0019] If the upper limit of conditional expression (1) is exceeded and the refractive power of the first lens group G1 becomes small, the convergence effect of the light rays emerging from the first lens group G1 becomes small, and the diameter of the second lens group G2 becomes large, which undesirably leads to an increase in the size of the optical system.

[0020] If the lower limit of conditional expression (1) is exceeded and the refractive power of the first lens group G1 becomes too large, spherical aberration and coma, mainly at the telephoto end, become too large, which is not desirable.

[0021] In order to ensure the effect of conditional expression (1), it is preferable to set the upper limit to 0.55 and the lower limit to 0.32.

[0022] Conditional formula (2) defines the ratio between the composite focal length of the first lens group G1 and the second lens group G2 at infinity at the wide-angle end, and the composite focal length of the third lens group G3 through the Lth lens group GL at infinity at the wide-angle end. In order to obtain a large angle of view at the wide-angle end while achieving a compact overall system, it is necessary to appropriately configure the power arrangement of a retrofocus type at the wide-angle end.

[0023] If the upper limit of conditional expression (2) is exceeded and the composite refractive power of the first lens group G1 and the second lens group G2 at infinity at the wide-angle end becomes weak, it becomes difficult to widen the angle of the entire system while maintaining a short overall optical length. Also, if the upper limit of conditional expression (2) is exceeded and the composite refractive power of the third lens group G3 through the Lth lens group GL at infinity at the wide-angle end becomes strong, it becomes difficult to reduce spherical aberration and coma.

[0024] If the lower limit of conditional expression (2) is exceeded and the composite refractive power of the first lens group G1 and the second lens group G2 at infinity at the wide-angle end becomes too strong, it becomes difficult to reduce astigmatism at the wide-angle end. Furthermore, the upward movement of on-axis rays emerging from the second lens group G2 becomes too strong, undesirably increasing the diameter of the third lens group G3 and subsequent groups. Furthermore, if the lower limit of conditional expression (2) is exceeded and the composite refractive power from the third lens group G3 to the Lth lens group GL at infinity at the wide-angle end becomes too weak, the overall length becomes too long, undesirably.

[0025] In order to ensure the effect of conditional expression (2), it is preferable to set the upper limit to 0.70 and the lower limit to 0.45.

[0026] The present invention is further characterized in that the distance between the 4A lens group G4A and the 4B lens group G4B at infinity remains constant during zooming.

[0027] By keeping the distance between the 4A lens group G4A and the 4B lens group G4B constant during magnification changes, mechanisms such as cams can be simplified, making it possible to reduce the size of the product. In addition, so-called zoom tracking, which maintains focus on the subject during magnification changes at infinity, is satisfied, enabling fast and stable focusing operations.

[0028] The present invention is further characterized in that the distance between the 3A lens group G3A and the 3B lens group G3B remains constant during zooming.

[0029] By keeping the distance between the 3A lens group G3A and the 3B lens group G3B constant, mechanisms such as cams can be simplified, and the product can be made more compact.

[0030] The present invention is further characterized in that each of the 3B lens groups G3B is a cemented lens composed of one positive lens and one negative lens.

[0031] If the weight of the lens group that is driven during image stabilization increases, the actuator required for driving it will also become larger, resulting in an increase in the size of the mechanism. In order to simultaneously achieve good aberration correction during image stabilization and a compact mechanism, it is necessary to minimize the number of lenses used in the 3B lens group G3B. By configuring the 3B lens group G3B with one positive lens and one negative lens, it becomes possible to suppress the chromatic aberration of magnification that occurs when the 3B lens group G3B is moved in a direction approximately perpendicular to the optical axis. Furthermore, using a cemented lens eliminates the need for mechanical elements such as spacers, allowing for further weight reduction.

[0032] The present invention is further characterized in that the 4B lens group G4B is a cemented lens composed of one negative lens or one positive lens and one negative lens.

[0033] To simultaneously achieve fast drive during focusing and a compact mechanism, it is necessary to reduce the weight of the lens group used for focusing. The weight of the 4B lens group G4B can be kept small by configuring the 4B lens group G4B as a single negative lens or a cemented lens consisting of a single positive lens and a single negative lens.

[0034] The present invention is further characterized in that the Lth lens group GL, which is positioned closest to the image side, is fixed relative to the image plane.

[0035] By fixing the Lth lens group GL, which is positioned closest to the image side, with respect to the image plane, it is possible to simplify mechanisms such as cams and to make the product more compact.

[0036] The present invention is further characterized in that the first lens group G1 comprises, in order from the object side, one negative lens and two positive lenses.

[0037] To simultaneously achieve high imaging performance and compact size, it is necessary to create an optimal configuration that can correct aberrations while minimizing the number of elements in the first lens group G1. By including a negative lens and a positive lens, it is possible to suppress chromatic aberration of magnification that occurs in the first lens group G1. Furthermore, by using two positive lenses, it is possible to minimize spherical aberration and coma aberration that occur in the first lens group G1, mainly at the telephoto end.

[0038] The present invention is further characterized in that the 4A lens group G4A includes at least two positive lenses and one negative lens.

[0039] From the wide-angle end to the telephoto end, axial rays pass through a high position within the 4A lens group G4A, resulting in significant spherical aberration and coma aberration within the 4A lens group G4A. The aberrations generated in the 4A lens group G4A are magnified by the 4B lens group G4B, which has negative refractive power. Therefore, in order to effectively correct various aberrations from infinity to close distances, it is necessary to suppress the aberrations generated within the 4A lens group G4A. Therefore, by configuring the 4A lens group G4A with at least two positive lenses, spherical aberration and coma aberration can be effectively corrected throughout the entire system. Furthermore, by including a positive lens and a negative lens in the 4A lens group G4A, axial chromatic aberration can be effectively corrected throughout the entire system.

[0040] The present invention is further characterized in that the following conditional expression is satisfied. (3) 0.60<|f4B / f4|<1.80 f4B: the focal length of the 4B lens group G4B f4: the focal length of the fourth lens group G4

[0041] Conditional expression (3) defines the ratio of the focal length of the fourth lens group G4B to the focal length of the fourth lens group G4.

[0042] If the upper limit of conditional expression (3) is exceeded and the refractive power of the 4B lens group G4B becomes small, the movement distance of the 4B lens group G4B during focusing becomes large, making it difficult to perform a fast focusing operation, which is undesirable. On the other hand, if the upper limit of conditional expression (3) is exceeded and the refractive power of the 4th lens group G4 becomes large, it becomes difficult to suppress astigmatism.

[0043] If the lower limit of conditional expression (3) is exceeded and the refractive power of the 4B lens group G4B becomes too large, it becomes difficult to suppress the astigmatism that occurs in the 4B lens group G4B, and the fluctuation in astigmatism from the infinity state to the close distance state becomes large, which is undesirable. Also, if the lower limit of conditional expression (3) is exceeded and the refractive power of the 4th lens group G4 becomes too small, the divergence of off-axial rays emerging from the 4th lens group G4 becomes large, which increases the diameter of the lens group on the image side of the 4th lens group G4 and makes the optical system larger.

[0044] In order to ensure the effect of conditional expression (3), it is preferable to set the upper limit to 1.60 and the lower limit to 0.85.

[0045] The present invention is further characterized in that the following conditional expression is satisfied. (4) 0.08 <FB / LT<0.20 FB: Back focus in air at the wide-angle end LT: Total optical length at the wide-angle end

[0046] Conditional formula (4) defines the ratio of the air-equivalent back focal length at the wide-angle end to the total optical length at the wide-angle end. Here, back focal length is the distance on the optical axis from the apex of the lens surface in the Lth lens group GL that is closest to the image to the image plane. By setting the back focal length appropriately, it is possible to reduce the size of the entire system.

[0047] If the upper limit of conditional expression (4) is exceeded and the back focus at the wide-angle end becomes large, it becomes difficult to keep the overall length of the optical system small, which is undesirable.

[0048] If the lower limit of conditional expression (4) is exceeded and the back focal length at the wide-angle end becomes small, the angle of the off-axis ray emerging from the Lth lens group GL onto the image plane becomes large, which is undesirable as it reduces the amount of peripheral light.

[0049] In order to ensure the effect of conditional expression (4), it is preferable to set the upper limit to 0.18 and the lower limit to 0.09.

[0050] The present invention is further characterized in that the following conditional expression is satisfied. (5) 0.50 <f3 / f4<5.00 f3: focal length of the third lens group G3 f4: the focal length of the fourth lens group G4

[0051] Conditional expression (5) defines the ratio of the focal length of the third lens group G3 to the focal length of the fourth lens group G4.

[0052] In the third lens group G3 and the fourth lens group G4, both on-axis and off-axis rays pass through high positions within the lens from the wide-angle end to the telephoto end. Therefore, in order to effectively correct various aberrations such as spherical aberration, coma, and astigmatism while keeping the optical system compact, it is important to set the refractive power of each group appropriately.

[0053] If the upper limit of conditional expression (5) is exceeded and the refractive power of the third lens group G3 becomes small, the convergence of light rays emerging from the third lens group G3 weakens, and the diameter of the fourth lens group G4 increases, making it difficult to reduce the diameter of the final product. Also, if the upper limit of conditional expression (5) is exceeded and the refractive power of the fourth lens group G4 becomes large, it becomes difficult to suppress astigmatism.

[0054] If the refractive power of the third lens group G3 becomes too large, exceeding the lower limit of conditional expression (5), it becomes difficult to effectively correct spherical aberration and coma. Also, if the refractive power of the fourth lens group G4 becomes too small, exceeding the lower limit of conditional expression (5), the divergence of off-axis rays emerging from the fourth lens group G4 increases, which increases the diameter of the lens group on the image side of the fourth lens group G4 and makes the optical system larger.

[0055] In order to ensure the effect of conditional expression (5), it is preferable to set the upper limit to 4.00 and the lower limit to 1.00.

[0056] The present invention is further characterized in that the following conditional expression is satisfied. (6) 0.010<ΔPgF_3A<0.073 ΔPgF_3A: The largest anomalous dispersion of the positive lens included in the 3A lens group G3A for the g-line and F-line

[0057] Condition (6) defines the largest value of the anomalous dispersion for the g-line and F-line of the positive lens included in the 3A lens group G3A. The anomalous dispersion of each lens included in the imaging optical system of the present invention is defined by the following formula. ΔPgF=PgF-0.64833+0.00180*νd ΔPgF: Anomalous dispersion of lenses included in the imaging optical system PgF: The partial dispersion ratio between the g-line and F-line of a lens included in an imaging optical system νd: Abbe number at the d line of the lens included in the imaging optical system

[0058] If the upper limit of conditional expression (6) is exceeded and the anomalous dispersion of the positive lens included in the 3A lens group G3A becomes large, the secondary spectrum will be overcorrected, making it difficult to effectively correct axial chromatic aberration from the wide-angle end to the telephoto end, which is undesirable.

[0059] If the lower limit of conditional expression (6) is exceeded and the anomalous dispersion of the positive lens included in the 3A lens group G3A becomes small, the secondary spectrum will be undercorrected, which is undesirable.

[0060] In order to ensure the effect of conditional expression (6), it is preferable to set the upper limit to 0.058 and the lower limit to 0.020.

[0061] The present invention is further characterized in that the following conditional expression is satisfied. (7) 0.010<ΔPgF_1<0.073 ΔPgF_1: The largest anomalous dispersion of the positive lens included in the first lens group G1 for the g-line and F-line

[0062] Conditional expression (7) defines the largest value of the anomalous dispersion for the g-line and F-line of the positive lens included in the first lens group G1.

[0063] When the upper limit of conditional expression (7) is exceeded and the anomalous dispersion of the positive lens included in the first lens group G1 becomes large, there is no suitable glass type available at present.

[0064] If the lower limit of conditional expression (7) is exceeded and the anomalous dispersion of the positive lens included in the first lens group G1 becomes small, the secondary spectrum will be undercorrected mainly at the telephoto end, which is undesirable.

[0065] In order to ensure the effect of conditional expression (7), it is preferable to set the upper limit to 0.058 and the lower limit to 0.020.

[0066] Next, the lens configuration of an embodiment of the high-magnification zoom lens of the present invention will be described. Note that in the following description, the lens configuration will be described in order from the object side to the image side.

[0067] In [Surface Data], the surface number is the number of the lens surface or aperture stop S counted from the object side, r is the radius of curvature of each surface, d is the spacing between each surface, and nd is the refraction for the d line (wavelength 587.56 nm). where vd is the Abbe number for the d-line, and PgF is the partial dispersion ratio for the g-line (wavelength 435.8 nm) and F-line (wavelength 486.1 nm).

[0068] An asterisk (*) next to a surface number indicates that the lens surface is aspherical, and BF represents the back focal length.

[0069] The (stop) attached to the surface number indicates that the aperture stop S is located at that position. The radius of curvature for the plane or aperture stop S is marked as ∞ (infinity).

[0070] [Aspherical Data] shows the values ​​of each coefficient that determines the aspherical shape of lens surfaces marked with an * in [Surface Data]. The aspherical shape is defined as follows: y is the displacement from the optical axis in a direction perpendicular to the optical axis, z is the displacement (sag) from the intersection of the aspherical surface and the optical axis in the direction of the optical axis, r is the radius of curvature of the reference sphere, K is the Conic coefficient, and A4, A6, . . ., and A12 are the aspherical coefficients of 4th, 6th, . . ., and 12th orders, respectively. The coordinates of the aspherical shape are expressed by the following equations: TIFF2025125276000002.tif22169

[0071] [Various Data] shows values ​​such as zoom ratio and focal length for each focal length state.

[0072] [Variable Distance Data] shows the variable distance and BF values ​​for each focal length state.

[0073] [Lens Group Data] shows the surface number of each lens group closest to the object and the composite focal length of the entire group.

[0074] In the aberration diagrams corresponding to the respective examples, d, g, and C represent the d-line, g-line, and C-line, respectively, and ΔS and ΔM represent the sagittal image surface and meridional image surface, respectively.

[0075] In addition, for all of the values ​​of the following specifications, the focal length f, radius of curvature r, lens surface spacing d, and other length units are given in millimeters (mm) unless otherwise specified; however, this is not a limitation, as optical systems can achieve equivalent optical performance with proportional magnification and proportional reduction.

[0076] In the lens construction diagrams of the respective embodiments, the arrows indicate the locus of the lens group when changing magnification from the wide-angle end to the telephoto end, I indicates the image plane, and the dashed line passing through the center indicates the optical axis. [Example]

[0077] FIG. 1 is a diagram showing the lens configuration of a high-magnification zoom lens according to a first embodiment of the present invention.

[0078] Example 1 includes, from the object side, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, an aperture stop S, a third lens group G3 having positive refractive power, a fourth lens group G4 having positive refractive power, and a fifth lens group G5 having positive refractive power. The third lens group G3 includes, from the object side, a 3A lens group G3A having positive refractive power and a 3B lens group G3B having negative refractive power. The fourth lens group G4 includes, from the object side, a 4A lens group G4A having positive refractive power and a 4B lens group G4B having negative refractive power. During image blur correction during vibration reduction, the 3B lens group G3B moves in a direction substantially perpendicular to the optical axis. During focusing from infinity to a close distance, the 4B lens group G4B moves toward the image plane. The fifth lens group G5 corresponds to the Lth lens group GL, which is located closest to the image side.

[0079] The first lens group G1 consists of, in order from the object side, a negative meniscus lens with a convex surface facing the object side, a positive meniscus lens with a convex surface facing the object side, and a positive meniscus lens with a convex surface facing the object side.

[0080] The second lens group G2 consists of, in order from the object side, a negative meniscus lens with a convex surface facing the object side, a cemented lens consisting of a biconcave lens and a biconvex lens, and a negative meniscus lens with a convex surface facing the image side.

[0081] The third lens group G3 is composed of, in order from the object side, a 3A lens group G3A composed of a biconvex lens and a cemented lens consisting of a biconvex lens and a biconcave lens, and a 3B lens group G3B composed of a cemented lens consisting of a positive meniscus lens with its convex surface facing the image side and a biconcave lens.

[0082] The fourth lens group G4 is composed of, in order from the object side, a 4A lens group G4A composed of a biconvex lens, a biconcave lens, and a biconvex lens, and a 4B lens group G4B composed of a cemented lens composed of a positive meniscus lens with its convex surface facing the image side and a biconcave lens.

[0083] The fifth lens group G5 is composed of, in order from the object side, a negative meniscus lens with its convex surface facing the object side, and a biconvex lens.

[0084] In the high-magnification zoom lens of Example 1, when zooming from the wide-angle end to the telephoto end, the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 decreases, and the distance between the fourth lens group G4 and the fifth lens group G5 increases. The fifth lens group G5 is fixed with respect to the image plane during zooming.

[0085] The specifications of the high-magnification zoom lens of Example 1 are shown below. Numerical Example 1 Unit: mm [Face Data] Surface number rd nd vd PgF Object surface ∞ (d0) 1 109.3687 1.5500 1.80610 33.27 0.5884 2 66.0813 7.3019 1.43700 95.10 0.5336 3 917.2712 0.1500 4 82.8968 5.6553 1.59282 68.62 0.5440 5 1226.6732 (d5) 6 843.3064 0.9000 1.95375 32.32 7 17.1873 5.8777 8 -45.3866 0.9000 1.59282 68.62 9 38.8278 5.0211 1.80809 22.76 10 -36.1920 0.3622 11* -31.2704 1.0000 1.76450 49.09 12* -229.1745 (d12) 13 (Aperture) ∞ 1.0001 14 28.4864 3.6144 1.57135 52.95 0.5553 15 -74.0294 0.1500 16 24.8293 3.7720 1.49700 81.61 0.5389 17 -153.8358 0.9000 2.00100 29.13 0.5995 18 74.5606 3.2487 19 -37.9845 2.1147 1.67270 32.17 20 -22.6649 0.9000 1.59201 67.02 21* 83.3308 (d21) 22 15.8733 6.5868 1.43700 95.10 23 -34.9701 0.1501 24 -71.3746 0.9000 2.00100 29.13 25 47.4713 0.3441 26* 41.9483 3.8875 1.59201 67.02 27* -28.4619 (d27) 28 -35.2496 2.6194 1.75211 25.05 29 -19.1229 0.9000 1.61881 63.85 30* 100.5407 (d30) 31 58.0854 0.9000 2.00100 29.13 32 34.6895 2.1291 33 49.4291 3.9521 1.51742 52.15 34 -537.8400 (BF) Image plane ∞ [Aspherical data] 11th floor 12th floor 21st floor 26th floor 27th floor K 0.00000 0.00000 0.00000 0.00000 0.00000 A4 3.52436E-05 2.39096E-05 -6.52626E-06 -6.03584E-05 2.01084E-05 A6 -2.46569E-07 -2.67116E-07 -1.29238E-08 -7.07509E-08 9.24124E-08 A8 5.14679E-10 5.57472E-10 1.65231E-10 4.54929E-09 3.77026E-09 A10 0.00000E+00 0.00000E+00 -9.71037E-13 -7.71649E-12 0.00000E+00 30 sides K 0.00000 A4 -2.94084E-06 A6 -5.49183E-08 A8 6.47510E-10 A10 1.74859E-12 [Various data] Zoom ratio 17.66 Wide-angle Mid-range Telephoto Focal length 16.48 73.48 291.00 F-number 3.60 5.66 6.90 Full angle of view 2ω 87.13 20.95 5.41 Image height Y 14.20 14.20 14.20 Lens length 145.77 198.45 243.83 [Variable Interval Data] Wide-angle Mid-range Telephoto d0 ∞ ∞ ∞ d5 1.5000 45.2944 83.4890 d12 38.9747 13.8131 2.0000 d21 9.5180 4.1882 2.0000 d27 1.5000 1.5000 1.5000 d30 9.7861 49.0921 70.3574 BF 17.7003 17.7003 17.7003 [Lens group data] Group Starting plane Focal length G1 1 126.13 G2 6 -16.06 G3 13 55.71 G4 22 46.10 G5 31 4514.46 G3A 13 30.50 G3B 19 -46.75 G4A 22 27.04 G4B 28 -48.68 [Example]

[0086] FIG. 11 is a diagram showing the lens configuration of a high-magnification zoom lens according to a second embodiment of the present invention.

[0087] Example 2 comprises, from the object side, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, an aperture stop S, a third lens group G3 having positive refractive power, a fourth lens group G4 having positive refractive power, and a fifth lens group G5 having positive refractive power. The third lens group G3 comprises, from the object side, a 3A lens group G3A having positive refractive power and a 3B lens group G3B having negative refractive power. The fourth lens group G4 comprises, from the object side, a 4A lens group G4A having positive refractive power and a 4B lens group G4B having negative refractive power. During image blur correction during vibration reduction, the 3B lens group G3B moves in a direction substantially perpendicular to the optical axis. During focusing from infinity to a close distance, the 4B lens group G4B moves toward the image plane. The fifth lens group G5 corresponds to the Lth lens group GL, which is located closest to the image side.

[0088] The first lens group G1 consists of, in order from the object side, a negative meniscus lens with a convex surface facing the object side, a positive meniscus lens with a convex surface facing the object side, and a positive meniscus lens with a convex surface facing the object side.

[0089] The second lens group G2 is composed of, in order from the object side, a negative meniscus lens with a convex surface facing the object side, a biconcave lens, and a cemented lens consisting of a biconvex lens and a negative meniscus lens with a convex surface facing the image side.

[0090] The third lens group G3 is composed of, in order from the object side, a 3A lens group G3A composed of a biconvex lens and a cemented lens consisting of a biconvex lens and a biconcave lens, and a 3B lens group G3B composed of a cemented lens consisting of a positive meniscus lens with its convex surface facing the image side and a biconcave lens.

[0091] The fourth lens group G4 is composed of, in order from the object side, a 4A lens group G4A composed of a biconvex lens, a cemented lens consisting of a biconvex lens and a biconcave lens, and a biconvex lens, and a 4B lens group G4B composed of a cemented lens consisting of a positive meniscus lens with its convex surface facing the image side and a biconcave lens.

[0092] The fifth lens group G5 is composed of, in order from the object side, a negative meniscus lens with its convex surface facing the object side, and a biconvex lens.

[0093] In the high-magnification zoom lens of Example 2, when zooming from the wide-angle end to the telephoto end, the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 decreases, and the distance between the fourth lens group G4 and the fifth lens group G5 increases. The fifth lens group G5 is fixed with respect to the image plane during zooming.

[0094] The specifications of the high-magnification zoom lens of Example 2 are shown below. Numerical Example 2 Unit: mm [Face Data] Surface number rd nd vd PgF Object surface ∞ (d0) 1 103.2436 1.5500 1.80610 33.27 0.5884 2 63.7486 7.2211 1.43700 95.10 0.5336 3 538.7114 0.1500 4 81.4412 5.6792 1.59282 68.62 0.5440 5 1115.1717 (d5) 6 775.2282 0.9000 1.91082 35.25 7 16.4132 6.1565 8* -33.7624 1.0000 1.59201 67.02 9* 86.4689 0.1500 10 43.9493 4.5837 1.80809 22.76 11 -40.6567 0.9000 1.77250 49.63 12 5318.2571 (d12) 13 (Aperture) ∞ 1.0000 14 26.2071 3.5822 1.54072 47.20 0.5678 15 -78.5508 0.1500 16 26.0109 3.6387 1.49700 81.61 0.5389 17 -102.4775 0.9000 2.00100 29.13 0.5995 18 79.2722 3.0937 19 -38.2212 2.0136 1.68893 31.16 20 -23.4974 0.9000 1.59201 67.02 21* 82.1288 (d21) 22 32.0342 3.4958 1.43700 95.10 23 -329.5864 0.1500 24 19.8715 4.0085 1.49700 81.61 25 -392.2178 0.9000 2.00100 29.13 26 31.4569 0.8176 27* 34.7403 3.8014 1.59201 67.02 28* -37.1102 (d28) 29 -72.8134 2.2165 1.75211 25.05 30 -30.8578 0.9000 1.59201 67.02 31* 36.0524 (d31) 32 93.8380 0.9000 2.00100 29.13 33 40.1321 2.2375 34 65.3460 4.6222 1.60342 38.01 35 -77.0648 (BF) Image plane ∞ [Aspherical data] 8th floor 9th floor 21st floor 27th floor 28th floor K 0.00000 0.00000 0.00000 0.00000 0.00000 A4 5.39139E-05 4.06945E-05 -6.52360E-06 -3.31668E-05 2.06783E-05 A6 -4.56671E-07 -5.16111E-07 -1.42896E-08 6.37360E-08 1.12194E-07 A8 1.84445E-09 2.18662E-09 2.29825E-10 1.50461E-09 6.89367E-10 A10 -3.30429E-12 -4.02770E-12 -1.40717E-12 -4.52047E-12 0.00000E+00 31 pages K 0.00000 A4 -1.46682E-08 A6 -8.98716E-08 A8 1.83802E-09 A10 -9.63256E-12 [Various data] Zoom ratio 17.66 Wide-angle Mid-range Telephoto Focal length 16.48 73.48 291.00 F-number 3.60 5.66 6.90 Full angle of view 2ω 86.56 20.96 5.41 Image height Y 14.20 14.20 14.20 Lens total length 146.79 200.14 245.06 [Variable Interval Data] Wide-angle Mid-range Telephoto d0 ∞ ∞ ∞ d5 1.5000 45.1776 83.4412 d12 39.4231 14.3069 2.0059 d21 8.7171 4.1048 2.0000 d28 1.5000 1.5000 1.5000 d31 11.1829 50.5497 71.6024 BF 16.8781 16.8781 16.8781 [Lens group data] Group Starting plane Focal length G1 1 126.48 G2 6 -16.57 G3 13 63.69 G4 22 43.57 G5 32 287.96 G3A 13 32.43 G3B 19 -47.10 G4A 22 26.55 G4B 28 -45.96 [Example]

[0095] FIG. 21 is a diagram showing the lens configuration of a high-magnification zoom lens according to a third embodiment of the present invention.

[0096] Example 3 comprises, from the object side, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, an aperture stop S, a third lens group G3 having positive refractive power, a fourth lens group G4 having positive refractive power, and a fifth lens group G5 having positive refractive power. The third lens group G3 comprises, from the object side, a 3A lens group G3A having positive refractive power and a 3B lens group G3B having negative refractive power. The fourth lens group G4 comprises, from the object side, a 4A lens group G4A having positive refractive power and a 4B lens group G4B having negative refractive power. During image blur correction during vibration reduction, the 3B lens group G3B moves in a direction substantially perpendicular to the optical axis. During focusing from infinity to a close distance, the 4B lens group G4B moves toward the image plane. The fifth lens group G5 corresponds to the Lth lens group GL, which is located closest to the image side.

[0097] The first lens group G1 is composed of, in order from the object side, a negative meniscus lens with a convex surface facing the object side, a biconvex lens, and a positive meniscus lens with a convex surface facing the object side.

[0098] The second lens group G2 is composed of, in order from the object side, a negative meniscus lens with a convex surface facing the object side, a biconcave lens, and a cemented lens consisting of a biconvex lens and a negative meniscus lens with a convex surface facing the image side.

[0099] The third lens group G3 is composed of, in order from the object side, a 3A lens group G3A composed of a biconvex lens and a cemented lens consisting of a biconvex lens and a biconcave lens, and a 3B lens group G3B composed of a cemented lens consisting of a positive meniscus lens with its convex surface facing the image side and a biconcave lens.

[0100] The fourth lens group G4 is composed of, in order from the object side, a 4A lens group G4A composed of a biconvex lens, a cemented lens consisting of a biconvex lens and a biconcave lens, and a biconvex lens, and a 4B lens group G4B composed of a cemented lens consisting of a positive meniscus lens with its convex surface facing the image side and a biconcave lens.

[0101] The fifth lens group G5 is composed of, in order from the object side, a negative meniscus lens with its convex surface facing the object side, and a biconvex lens.

[0102] In the high-magnification zoom lens of Example 3, when zooming from the wide-angle end to the telephoto end, the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 decreases, and the distance between the fourth lens group G4 and the fifth lens group G5 increases. The fifth lens group is fixed with respect to the image plane during zooming.

[0103] The specifications of the high-magnification zoom lens of Example 3 are shown below. Numerical Example 3 Unit: mm [Face Data] Surface number rd nd vd PgF Object surface ∞ (d0) 1 118.8841 1.5500 1.80610 33.27 0.5884 2 70.0228 7.4863 1.43700 95.10 0.5336 3 -2402.5913 0.1500 4 80.3410 5.8476 1.59282 68.62 0.5440 5 675.7919 (d5) 6 485.6242 0.9000 1.95375 32.32 7 16.7430 5.8285 8* -43.1161 1.0000 1.59201 67.02 9* 64.4976 0.2815 10 52.7306 5.4828 1.75211 25.05 11 -22.5163 0.9000 1.72916 54.67 12 -408.4979 (d12) 13 (Aperture) ∞ 1.0000 14 30.9666 3.4000 1.54072 47.20 0.5678 15 -63.5513 0.1517 16 25.0482 3.5271 1.49700 81.61 0.5389 17 -79.0529 0.9000 2.00100 29.13 0.5995 18 92.9187 2.9833 19 -40.5363 2.0695 1.69895 30.05 20 -22.8952 0.9000 1.59201 67.02 21* 60.7550 (d21) 22 24.9347 3.5949 1.55032 75.50 23 -174.0996 0.1500 24 37.0230 2.8841 1.59282 68.62 25 -445.9978 0.9000 2.00100 29.13 26 29.5861 0.3434 27* 24.7835 4.0436 1.59201 67.02 28* -48.7516 (d28) 29 -410.3724 2.0910 1.76182 26.61 30 -54.9954 0.9000 1.59201 67.02 31* 23.0380 (d31) 32 70.2250 0.9000 1.95375 32.32 33 26.9449 0.1500 34 26.0345 6.2541 1.58144 40.89 35 -194.4494 (BF) Image plane ∞ [Aspherical data] 8th floor 9th floor 21st floor 27th floor 28th floor K 0.00000 0.00000 0.00000 0.00000 0.00000 A4 2.23406E-05 5.87171E-06 -7.05642E-06 -2.34043E-05 2.38348E-05 A6 -5.92061E-07 -5.76131E-07 5.82547E-09 2.41225E-08 9.84370E-08 A8 4.90497E-09 4.84268E-09 9.78902E-11 1.51538E-09 9.01072E-10 A10 -1.50741E-11 -1.50530E-11 -1.20622E-12 -2.49357E-12 0.00000E+00 A12 0.00000E+00 0.00000E+00 0.00000E+00 0.00000E+00 0.00000E+00 31 pages K 0.00000 A4 1.44502E-06 A6 -2.10702E-07 A8 4.22508E-09 A10 -3.95449E-11 A12 1.65036E-13 [Various data] Zoom ratio 17.65 Wide-angle Mid-range Telephoto Focal length 16.48 73.48 291.00 F-number 3.61 6.03 6.90 Full angle of view 2ω 86.28 20.96 5.43 Image height Y 14.20 14.20 14.20 Lens total length 146.31 202.49 238.32 [Variable Interval Data] Wide-angle Mid-range Telephoto d0 ∞ ∞ ∞ d5 1.3000 45.3108 82.8571 d12 36.5543 14.0107 1.8000 d21 9.9515 4.8856 1.8000 d28 1.5000 1.5000 1.5000 d31 12.6529 52.4418 65.9970 BF 17.8001 17.8001 17.8001 [Lens group data] Group Starting plane Focal length G1 1 122.57 G2 6 -16.33 G3 13 72.36 G4 22 40.97 G5 32 274.29 G3A 13 33.10 G3B 19 -44.46 G4A 22 24.87 G4B 28 -40.82 [Example]

[0104] FIG. 31 is a diagram showing the lens configuration of a high-magnification zoom lens according to a fourth embodiment of the present invention.

[0105] Example 4 includes, from the object side, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, an aperture stop S, a third lens group G3 having positive refractive power, a fourth lens group G4 having positive refractive power, and a fifth lens group G5 having positive refractive power. The third lens group G3 includes, from the object side, a 3A lens group G3A having positive refractive power and a 3B lens group G3B having negative refractive power. The fourth lens group G4 includes, from the object side, a 4A lens group G4A having positive refractive power and a 4B lens group G4B having negative refractive power. During image blur correction during vibration reduction, the 3B lens group G3B moves in a direction substantially perpendicular to the optical axis. During focusing from infinity to a close distance, the 4B lens group G4B moves toward the image plane. The fifth lens group G5 corresponds to the Lth lens group GL, which is located closest to the image side.

[0106] The first lens group G1 is composed of, in order from the object side, a negative meniscus lens with a convex surface facing the object side, a biconvex lens, and a positive meniscus lens with a convex surface facing the object side.

[0107] The second lens group G2 is composed of, in order from the object side, a negative meniscus lens with a convex surface facing the object side, a biconcave lens, and a cemented lens consisting of a biconvex lens and a negative meniscus lens with a convex surface facing the image side.

[0108] The third lens group G3 is composed of, in order from the object side, a 3A lens group G3A composed of a biconvex lens and a cemented lens consisting of a biconvex lens and a negative meniscus lens with its convex surface facing the image side, and a 3B lens group G3B composed of a cemented lens consisting of a positive meniscus lens with its convex surface facing the image side and a biconcave lens.

[0109] The fourth lens group G4 is composed of, in order from the object side, a 4A lens group G4A composed of a biconvex lens, a biconvex lens, and a cemented lens composed of a negative meniscus lens with its convex surface facing the object side and a biconvex lens, and a 4B lens group G4B composed of a negative meniscus lens with its convex surface facing the object side.

[0110] The fifth lens group G5 is composed of, in order from the object side, a cemented lens consisting of a biconvex lens and a negative meniscus lens with its convex surface facing the image side.

[0111] In the high-magnification zoom lens of Example 4, when zooming from the wide-angle end to the telephoto end, the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 decreases, and the distance between the fourth lens group G4 and the fifth lens group G5 increases. The fifth lens group G5 is fixed with respect to the image plane during zooming.

[0112] The specifications of the high-magnification zoom lens according to Example 4 are shown below. Numerical Example 4 Unit: mm [Face Data] Surface number rd nd vd PgF Object surface ∞ (d0) 1 116.3748 1.5500 1.77047 29.74 0.5951 2 68.3039 6.9297 1.55032 75.50 0.5401 3 -2997.5168 0.1500 4 87.1562 4.4452 1.59282 68.62 5 302.8455 (d5) 6 529.8137 0.9000 2.00100 29.13 7 17.4115 5.9157 8* -52.6206 1.0000 1.59201 67.02 9* 43.9475 0.3972 10 47.5334 6.2138 1.84666 23.78 11 -24.0353 0.7000 1.87070 40.73 12 -207.0889 (d12) 13 (Aperture) ∞ 1.0000 14 39.0214 2.9898 1.56732 42.82 0.5731 15 -56.7981 0.1500 16 31.9627 3.1470 1.43700 95.10 0.5336 17 -49.0264 0.9000 2.00100 29.13 0.5995 18 -1059.6443 2.9815 19 -32.2654 1.7584 1.80518 25.46 20* -21.1686 0.9000 1.59201 67.02 21* 72.6089 (d21) 22* 25.7264 4.0290 1.55332 71.69 23* -45.7796 0.1500 24 63.7008 2.4029 1.43700 95.10 25 -281.8985 0.1500 26 80.8058 0.9000 2.00100 29.13 27 21.0580 4.9262 1.59410 60.47 28 -140.2849 (d28) 29* 39.7565 0.9000 1.59201 67.02 30* 17.3521 (d30) 31 147.0748 4.7991 1.64769 33.84 32 -78.3862 0.7000 2.00069 25.46 33 -251.1533 (BF) Image plane ∞ [Aspherical data] 8th page 9th page 20th page 21st page 22nd page K 0.00000 0.00000 0.00000 0.00000 0.00000 A4 2.36411E-05 4.77811E-06 0.00000E+00 -6.54233E-06 -1.81016E-05 A6 -4.60758E-07 -4.51453E-07 0.00000E+00 -7.46116E-09 -5.68522E-08 A8 3.04297E-09 2.98017E-09 0.00000E+00 3.43006E-10 3.37094E-10 A10 -8.64361E-12 -8.20791E-12 0.00000E+00 -1.84406E-12 0.00000E+00 A12 0.00000E+00 0.00000E+00 0.00000E+00 0.00000E+00 0.00000E+00 23 pages 29 pages 30 pages K 0.00000 0.00000 0.00000 A4 1.29457E-05 -9.01196E-07 -9.63943E-06 A6 -9.37840E-08 -8.94787E-10 -2.05196E-08 A8 4.66364E-10 9.63729E-12 5.09093E-10 A10 0.00000E+00 6.55361E-13 -1.10749E-11 A12 0.00000E+00 0.00000E+00 5.50621E-14 [Various data] Zoom ratio 14.71 Wide-angle Mid-range Telephoto Focal length 16.48 64.00 242.50 F-number 3.61 5.56 6.90 Full angle of view 2ω 86.52 23.97 6.54 Image height Y 14.20 14.20 14.20 Lens total length 146.00 192.15 236.33 [Variable Interval Data] Wide-angle Mid-range Telephoto d0 ∞ ∞ ∞ d5 1.5716 40.7114 74.5819 d12 33.5376 12.5729 1.8000 d21 13.4937 6.6573 1.8000 d28 1.8556 1.8556 1.8556 d30 12.0037 46.8095 72.7524 BF 22.5947 22.5548 22.5548 [Lens group data] Group Starting plane Focal length G1 1 119.17 G2 6 -17.06 G3 13 100.30 G4 22 37.86 G5 31 256.97 G3A 13 35.56 G3B 19 -43.37 G4A 22 26.13 G4B 28 -52.80 [Example]

[0113] FIG. 41 is a lens configuration diagram of a high-magnification zoom lens according to a fifth embodiment of the present invention.

[0114] Example 5 includes, from the object side, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, an aperture stop S, a third lens group G3 having positive refractive power, a fourth lens group G4 having positive refractive power, and a fifth lens group G5 having positive refractive power. The third lens group G3 includes, from the object side, a 3A lens group G3A having positive refractive power and a 3B lens group G3B having negative refractive power. The fourth lens group G4 includes, from the object side, a 4A lens group G4A having positive refractive power and a 4B lens group G4B having negative refractive power. During image blur correction during vibration reduction, the 3B lens group G3B moves in a direction substantially perpendicular to the optical axis. During focusing from infinity to a close distance, the 4B lens group G4B moves toward the image plane. The fifth lens group G5 corresponds to the Lth lens group GL, which is located closest to the image side.

[0115] The first lens group G1 consists of, in order from the object side, a negative meniscus lens with a convex surface facing the object side, a positive meniscus lens with a convex surface facing the object side, and a positive meniscus lens with a convex surface facing the object side.

[0116] The second lens group G2 is composed of, in order from the object side, a negative meniscus lens with a convex surface facing the object side, a biconcave lens, and a cemented lens composed of a biconvex lens and a biconcave lens.

[0117] The third lens group G3 is composed of, in order from the object side, a 3A lens group G3A composed of a biconvex lens and a cemented lens consisting of a biconvex lens and a biconcave lens, and a 3B lens group G3B composed of a cemented lens consisting of a positive meniscus lens with its convex surface facing the image side and a biconcave lens.

[0118] The fourth lens group G4 is composed of, in order from the object side, a 4A lens group G4A composed of a biconvex lens, a biconvex lens, and a cemented lens consisting of a negative meniscus lens with its convex surface facing the object side and a biconvex lens, and a 4B lens group G4B composed of a cemented lens consisting of a positive meniscus lens with its convex surface facing the image side and a biconcave lens.

[0119] The fifth lens group G5 is composed of a cemented lens that includes, in order from the object side, a positive meniscus lens with a convex surface facing the image side and a negative meniscus lens with a convex surface facing the image side.

[0120] In the high-magnification zoom lens of Example 5, when zooming from the wide-angle end to the telephoto end, the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 decreases, and the distance between the fourth lens group G4 and the fifth lens group G5 increases. The fifth lens group G5 is fixed with respect to the image plane during zooming.

[0121] The specifications of the high-magnification zoom lens according to Example 5 are shown below. Numerical Example 5 Unit: mm [Face Data] Surface number rd nd vd PgF Object surface ∞ (d0) 1 106.8386 1.5500 1.80610 33.27 0.5884 2 59.4803 7.4150 1.55032 75.50 0.5401 3 522.9275 0.1500 4 72.0349 5.7699 1.59282 68.62 0.5440 5 373.5800 (d5) 6 269.1183 0.9000 2.05090 26.94 7 16.6261 5.0616 8* -135.4091 1.0000 1.59201 67.02 9* 32.4548 0.5198 10 38.8520 7.6536 1.84666 23.78 11 -16.2500 0.7000 1.87070 40.73 12 239.2102 (d12) 13 (Aperture) ∞ 1.0000 14 27.5698 3.0480 1.61772 49.81 0.5603 15 -125.3575 0.1500 16 31.3132 3.1224 1.49700 81.61 0.5389 17 -67.3797 0.9000 1.92119 23.96 0.6202 18 158.1299 2.7973 19 -39.1978 1.6622 1.69895 30.05 20* -22.3292 0.9000 1.59201 67.02 21* 63.5739 (d21) 22* 25.9286 3.9242 1.55332 71.69 23* -45.2119 0.1500 24 170.7771 2.2122 1.49700 81.61 25 -98.7406 0.1500 26 253.4673 0.9000 2.00100 29.13 27 23.2142 4.5718 1.59282 68.62 28 -45.6031 (d28) 29 -95.6450 2.1788 1.72825 28.32 30 -25.5817 0.7000 1.59349 67.00 31 31.3175 (d31) 32 -390.7541 5.1449 1.54814 45.82 33 -26.9478 0.7000 2.00100 29.13 34 -53.8103 (BF) Image plane ∞ [Aspherical data] 8th page 9th page 20th page 21st page 22nd page K 0.00000 0.00000 0.00000 0.00000 0.00000 A4 7.14491E-05 4.55732E-05 0.00000E+00 -6.65377E-06 -2.01094E-05 A6 -9.70874E-07 -1.03416E-06 0.00000E+00 -3.73114E-08 -4.52995E-08 A8 5.48008E-09 5.80657E-09 0.00000E+00 4.11200E-10 -5.20971E-10 A10 -1.21178E-11 -1.32370E-11 0.00000E+00 -4.62914E-13 0.00000E+00 23 sides K 0.00000 A4 2.11553E-05 A6 -4.39308E-08 A8 -6.17686E-10 A10 0.00000E+00 [Various data] Zoom ratio 18.81 Wide-angle Mid-range Telephoto Focal length 16.50 69.25 310.35 F-number 4.11 5.46 6.88 Full angle of view 2ω 84.80 22.20 5.09 Image height Y 14.20 14.20 14.20 Lens total length 146.00 196.20 235.00 [Variable Interval Data] Wide-angle Mid-range Telephoto d0 ∞ ∞ ∞ d5 1.3000 42.4639 75.5228 d12 35.4332 14.2582 1.9297 d21 10.6484 6.5999 1.8000 d28 1.6708 1.6708 1.6708 d31 13.6658 47.9249 70.7963 BF 18.3800 18.3493 18.3487 [Lens group data] Group Starting plane Focal length G1 1 113.68 G2 6 -14.81 G3 13 66.24 G4 22 41.30 G5 32 1916.27 G3A 13 31.38 G3B 19 -44.44 G4A 22 25.91 G4B 28 -46.63

[0122] Below is a list of values ​​corresponding to the conditional expressions in the above-mentioned embodiments. [Conditional expression corresponding value] Conditional expression EX1 EX2 EX3 EX4 EX5 (1) 0.43 0.43 0.42 0.49 0.37 (2) 0.58 0.57 0.59 0.61 0.57 (3) 1.06 1.06 1.00 1.39 1.13 (4) 0.12 0.11 0.12 0.15 0.13 (5) 1.21 1.46 1.77 2.65 1.60 (6) 0.037 0.056 0.056 0.027 0.027 (7) 0.056 0.037 0.037 0.056 0.037

[0123] <Other embodiments> The technology disclosed in the present embodiment is not limited to the above-described embodiments and examples, and various modifications are possible. The shapes and numerical values ​​of each part shown in the above-described numerical examples are examples for implementing the present technology, and the technical scope of the present technology should not be interpreted as being limited by these.

[0124] This technology can be configured as follows: [1] From the object side, a first lens group G1 having positive refractive power; a second lens group G2 having negative refractive power; a third lens group G3 having positive refractive power; a fourth lens group G4 having positive refractive power; an L-th lens group GL having positive refractive power and located closest to the image side; and When zooming from the wide-angle end to the telephoto end, the spacing between the lens groups changes, The third lens group G3 is composed of a 3A lens group G3A having a positive refractive power and a 3B lens group G3B having a negative refractive power, Image blur correction is performed by moving the 3B lens group G3B in a direction substantially perpendicular to the optical axis, The fourth lens group G4 is composed of a 4A lens group G4A having a positive refractive power and a 4B lens group G4B having a negative refractive power, The 4B lens group G4B is moved from the object side to the image side along the optical axis to perform focusing from an infinity state to a close distance. A high-magnification zoom lens characterized by satisfying the following conditional expressions: (1) 0.25 <f1 / fT<0.66 (2) 0.35<|ff / fr|<0.80 f1: focal length of the first lens group G1 fT: focal length of the entire system at infinity at the telephoto end ff: composite focal length of the first lens group G1 and the second lens group G2 at infinity at the wide-angle end fr: composite focal length from the third lens group G3 to the L lens group GL at infinity at the wide-angle end [2] The present invention is the high-magnification zoom lens according to [1], further characterized in that the distance between the 4A lens group G4A and the 4B lens group G4B in the infinity state is constant during zooming. [3] The present invention is the high-magnification zoom lens according to [1] or [2], further characterized in that the distance between the 3A lens group G3A and the 3B lens group G3B is constant during zooming. [4] The present invention is a high-magnification zoom lens according to any one of [1] to [3], further characterized in that the 3B lens group G3B is a cemented lens each composed of one positive lens and one negative lens. [5] The present invention is a high-magnification zoom lens according to any one of [1] to [4], further characterized in that the 4B lens group G4B is a cemented lens consisting of one negative lens or one positive lens and one negative lens. [6] The present invention is a high-magnification zoom lens according to any one of [1] to [5], further characterized in that the Lth lens group GL located closest to the image side is fixed with respect to the image plane. [7] The present invention is a high-magnification zoom lens according to any one of [1] to [6], further characterized in that the first lens group G1 consists of, in order from the object side, one negative lens and two positive lenses. [8] The present invention is a high-magnification zoom lens according to any one of [1] to [7], further characterized in that the 4A lens group G4A includes at least two positive lenses and one negative lens. [9] The present invention provides a high-magnification zoom lens according to any one of [1] to [8], characterized in that the following conditions are further satisfied: (3) 0.60<|f4B / f4|<1.80 f4B: the focal length of the 4B lens group G4B f4: the focal length of the fourth lens group G4

[10] The present invention provides a high-magnification zoom lens according to any one of [1] to [9], characterized in that the following conditions are further satisfied: (4) 0.08 <FB / LT<0.20 FB: Back focus in air at the wide-angle end LT: Total optical length at the wide-angle end

[11] The present invention provides a high-magnification zoom lens according to any one of [1] to

[10] , characterized in that the following conditions are further satisfied: (5) 0.50 <f3 / f4<5.00 f3: focal length of the third lens group G3 f4: the focal length of the fourth lens group G4

[12] The present invention provides a high-magnification zoom lens according to any one of [1] to

[11] , characterized in that the following conditions are further satisfied: (6) 0.010<ΔPgF_3A<0.073 ΔPgF_3A: The largest anomalous dispersion of the positive lens included in the 3A lens group G3A for the g-line and F-line

[13] The present invention provides a high-magnification zoom lens according to any one of [1] to

[12] , characterized in that the following conditions are further satisfied: (7) 0.010<ΔPgF_1<0.073 ΔPgF_1: The largest anomalous dispersion of the positive lens included in the first lens group G1 for the g-line and F-line [Explanation of symbols]

[0125] G1 First lens group G2 Second lens group G3 Third lens group G4 4th lens group G5 5th lens group GL final lens group S aperture stop I image plane

Claims

1. From the object side, a first lens group G1 having a positive refractive power; a second lens group G2 having negative refractive power; a third lens group G3 having positive refractive power; a fourth lens group G4 having positive refractive power; an L-th lens group GL having positive refractive power and positioned closest to the image side; and When zooming from the wide-angle end to the telephoto end, the spacing between the lens groups changes, The third lens group G3 is composed of a 3A lens group G3A having a positive refractive power and a 3B lens group G3B having a negative refractive power, Image blur correction is performed by moving the 3B lens group G3B in a direction substantially perpendicular to the optical axis, The fourth lens group G4 is composed of a 4A lens group G4A having a positive refractive power and a 4B lens group G4B having a negative refractive power, The 4B lens group G4B is moved from the object side to the image side in the optical axis direction to perform focusing from an infinity state to a close distance, A high-magnification zoom lens characterized by satisfying the following conditional expressions: (1) 0.25<f1 / fT<0.66 (2) 0.35<|ff / fr|<0.80 f1: focal length of the first lens group G1 fT: focal length of the entire system at infinity at the telephoto end ff: composite focal length of the first lens group G1 and the second lens group G2 at infinity at the wide-angle end fr: composite focal length from the third lens group G3 to the L lens group GL at infinity at the wide-angle end

2. 2. The high-magnification zoom lens according to claim 1, further characterized in that the distance between the 4A lens group G4A and the 4B lens group G4B in the infinity state is constant during zooming.

3. 2. The high-magnification zoom lens according to claim 1, further characterized in that the distance between the 3A lens group G3A and the 3B lens group G3B is constant during zooming.

4. The present invention is a high-magnification zoom lens according to claim 1, further characterized in that the 3B lens group G3B is a cemented lens composed of one positive lens and one negative lens.

5. The present invention is a high-magnification zoom lens according to claim 1, further characterized in that the 4B lens group G4B is a cemented lens consisting of one negative lens or one positive lens and one negative lens.

6. 2. The high-magnification zoom lens according to claim 1, wherein the Lth lens group GL located closest to the image side is fixed relative to the image plane.

7. The present invention is a high-magnification zoom lens according to claim 1, further characterized in that the first lens group G1 comprises, in order from the object side, one negative lens and two positive lenses.

8. The present invention further provides a high-magnification zoom lens according to claim 1, wherein the 4A lens group G4A includes at least two positive lenses and one negative lens.

9. The present invention provides a high-magnification zoom lens according to any one of claims 1 to 8, characterized in that the following conditional expression is further satisfied: (3) 0.60<|f4B / f4|<1.80 f4B: focal length of the 4B lens group G4B f4: focal length of the fourth lens group G4

10. The present invention provides a high-magnification zoom lens according to any one of claims 1 to 8, characterized in that the following conditional expression is further satisfied: (4) 0.08<FB / LT<0.20 FB: Back focus in air equivalent at the wide-angle end LT: Total optical length at the wide-angle end

11. The present invention provides a high-magnification zoom lens according to any one of claims 1 to 8, characterized in that the following conditional expression is further satisfied: (5) 0.50<f3 / f4<5.00 f3: focal length of the third lens group G3 f4: focal length of the fourth lens group G4

12. The present invention provides a high-magnification zoom lens according to any one of claims 1 to 8, characterized in that the following conditional expression is further satisfied: (6) 0.010<ΔPgF_3A<0.073 ΔPgF_3A: the largest anomalous dispersion of the positive lens included in the 3A lens group G3A for the g-line and F-line

13. The present invention provides a high-magnification zoom lens according to any one of claims 1 to 8, characterized in that the following conditional expression is further satisfied: (7) 0.010<ΔPgF_1<0.073 ΔPgF_1: the largest anomalous dispersion of the positive lens included in the first lens group G1 for the g-line and the F-line

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