Variable magnification optical system and optical apparatus

Abstract

A variable magnification optical system (ZL) has a front lens group (GA) having positive refractive power, a first intermediate lens group (GM1) having negative refractive power, a second intermediate lens group (GM2) having positive refractive power, and a rear lens group (GR) containing a plurality of focus lens groups that move along an optical axis when focusing is performed, the variable magnification optical system (ZL) satisfying the following conditional expressions: -0.37 < fFs / fFy < 0.37, 2.00 < f1 / fw < 8.00 where fFs is a focal length of a focus lens group having the strongest refractive power among the focus lens groups, fFy is a focal length of a focus lens group having the weakest refractive power among the focus lens groups, f1 is a focal length of the front lens group (GA), and fw is a focal length of the variable magnification optical system (ZL) in a wide-angle end state.

Description

Technical Field

[0001] This invention relates to a zoom optical system, an optical device, and a method for manufacturing a zoom optical system. Background Technology

[0002] Previously, zoom optical systems suitable for photographic cameras, electronic still cameras, video cameras, etc., have been disclosed (for example, see Patent Document 1). In such zoom optical systems, it is difficult to suppress aberrations during focusing.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2019-12243 Summary of the Invention

[0006] The zoom optical system of the present invention comprises a front lens group with positive optical power, a first intermediate lens group with negative optical power, a second intermediate lens group with positive optical power, and a subsequent lens group arranged sequentially along the optical axis from the object side. During zooming, the spacing between adjacent lens groups changes. The subsequent lens group includes: a first focusing lens group disposed on the object side of the subsequent lens group and moving along the optical axis during focusing; and at least one other focusing lens group disposed on the image side compared to the first focusing lens group and moving along the optical axis along a different trajectory than the first focusing lens group during focusing. The zoom optical system satisfies the following condition:

[0007] -0.37 <fFs / fFy<0.37

[0008] 2.00 <f1 / fw<8.00

[0009] Wherein, fFs: the focal length of the focusing lens group with the strongest optical power among the focusing lens groups included in the subsequent lens group.

[0010] fFy: The focal length of the weakest focusing lens group among the focusing lens groups included in the subsequent lens group.

[0011] f1: Focal length of the front lens group

[0012] fw: The focal length of the zoom optical system in the wide-angle state.

[0013] The optical device of the present invention is configured to include the above-described zoom optical system.

[0014] The present invention discloses a method for manufacturing a zoom optical system comprising a front lens group having positive optical power, a first intermediate lens group having negative optical power, a second intermediate lens group having positive optical power, and a subsequent lens group arranged sequentially along the optical axis from the object side. The lenses are configured within the lens barrel in such a manner that the spacing between adjacent lens groups changes during zooming. The subsequent lens group includes: a first focusing lens group disposed on the object side of the subsequent lens group and moving along the optical axis during focusing; and at least one other focusing lens group disposed on the image side compared to the first focusing lens group and moving along the optical axis along a different trajectory than the first focusing lens group during focusing. The zoom optical system satisfies the following condition:

[0015] -0.37 <fFs / fFy<0.37

[0016] 2.00 <f1 / fw<8.00

[0017] Wherein, fFs: the focal length of the focusing lens group with the strongest optical power among the focusing lens groups included in the subsequent lens group.

[0018] fFy: The focal length of the weakest focusing lens group among the focusing lens groups included in the subsequent lens group.

[0019] f1: Focal length of the front lens group

[0020] fw: The focal length of the zoom optical system in the wide-angle state. Attached Figure Description

[0021] Figure 1 This is a diagram showing the lens structure of the zoom optical system of the first embodiment.

[0022] Figure 2 (A) Figure 2 (B) are aberration diagrams of the zoom optical system of the first embodiment at infinity focusing in the wide-angle end state and the telephoto end state.

[0023] Figure 3 (A) Figure 3 (B) are aberration diagrams of close-range focusing in the wide-angle and telephoto states of the zoom optical system of the first embodiment.

[0024] Figure 4 This is a diagram showing the lens structure of the zoom optical system of the second embodiment.

[0025] Figure 5 (A) Figure 5(B) are aberration diagrams of the wide-angle and telephoto states of the zoom optical system of the second embodiment when focusing at infinity.

[0026] Figure 6 (A) Figure 6 (B) are aberration diagrams of close-range focusing in the wide-angle and telephoto states of the zoom optical system of the second embodiment.

[0027] Figure 7 This is a diagram showing the lens structure of the zoom optical system of the third embodiment.

[0028] Figure 8 (A) Figure 8 (B) are aberration diagrams of the zoom optical system of the third embodiment at infinity focusing in the wide-angle end state and the telephoto end state.

[0029] Figure 9 (A) Figure 9 (B) are aberration diagrams of close-range focusing in the wide-angle and telephoto states of the zoom optical system of the third embodiment.

[0030] Figure 10 This is a diagram showing the lens structure of the zoom optical system of the fourth embodiment.

[0031] Figure 11 (A) Figure 11 (B) are aberration diagrams of the zoom optical system of the fourth embodiment at infinity focusing in the wide-angle end state and the telephoto end state.

[0032] Figure 12 (A) Figure 12 (B) are aberration diagrams of close-range focusing in the wide-angle and telephoto states of the zoom optical system of the fourth embodiment.

[0033] Figure 13 This is a diagram showing the lens structure of the zoom optical system of the fifth embodiment.

[0034] Figure 14 (A) Figure 14 (B) are aberration diagrams of the zoom optical system of the fifth embodiment at infinity focusing in the wide-angle end state and the telephoto end state.

[0035] Figure 15 (A) Figure 15 (B) are aberration diagrams of close-range focusing in the wide-angle and telephoto states of the zoom optical system of the fifth embodiment.

[0036] Figure 16This is a diagram showing the lens structure of the zoom optical system of the sixth embodiment.

[0037] Figure 17 (A) Figure 17 (B) are aberration diagrams of the wide-angle and telephoto states of the zoom optical system of the sixth embodiment when focusing at infinity.

[0038] Figure 18 (A) Figure 18 (B) are aberration diagrams of close-range focusing in the wide-angle and telephoto states of the zoom optical system of the sixth embodiment.

[0039] Figure 19 This is a diagram showing the lens structure of the zoom optical system of the seventh embodiment.

[0040] Figure 20 (A) Figure 20 (B) are aberration diagrams of the zoom optical system of the 7th embodiment at infinity focusing in the wide-angle end state and the telephoto end state.

[0041] Figure 21 (A) Figure 21 (B) are aberration diagrams of close-range focusing in the wide-angle and telephoto states of the zoom optical system of the 7th embodiment, respectively.

[0042] Figure 22 This is a diagram showing the structure of a camera equipped with the zoom optical system of this embodiment.

[0043] Figure 23 This is a flowchart illustrating a method for manufacturing the zoom optical system of this embodiment. Detailed Implementation

[0044] The preferred embodiments of the present invention will be described below. First, according to... Figure 22 A camera (optical device) equipped with the zoom optical system of this embodiment will be described. For example... Figure 22 As shown, the camera 1 consists of a main body 2 and a camera lens 3 mounted on the main body 2. The main body 2 includes an image sensor 4, a main control unit (not shown) for controlling the operation of the digital camera, and an LCD screen 5. The camera lens 3 includes: a zoom optical system ZL, which consists of multiple lens groups; and a lens position control mechanism (not shown) for controlling the position of each lens group. The lens position control mechanism consists of a sensor for detecting the position of the lens groups, a motor for moving the lens groups back and forth along the optical axis, and a control circuit for driving the motor.

[0045] Light from the subject is focused by the zoom optical system ZL of the camera lens 3 and reaches the image plane I of the image sensor 4. The light from the subject reaching the image plane I is photoelectrically converted by the image sensor 4 and recorded as digital image data in a memory (not shown). The digital image data recorded in the memory can be displayed on the LCD screen 5 according to user operation. Furthermore, this camera can be a mirrorless camera or a single-lens reflex camera with a quick-return mirror. Figure 22 The zoom optical system ZL shown schematically illustrates the zoom optical system of the camera lens 3, but the lens structure of the zoom optical system ZL is not limited to this structure.

[0046] Next, the zoom optical system of this embodiment will be described. For example... Figure 1 As shown, the zoom optical system (zoom lens) ZL is an example of the zoom optical system in this embodiment.

[0047] ZL(1) is configured to include a front lens group GA with positive optical power, a first intermediate lens group GM1 with negative optical power, a second intermediate lens group GM2 with positive optical power, and a subsequent lens group GR arranged sequentially along the optical axis from the object side. During zooming, the spacing between adjacent lens groups changes. The subsequent lens group GR includes: a first focusing lens group GF1, disposed on the object side of the subsequent lens group GR, which moves along the optical axis during focusing; and at least one other focusing lens group, disposed on the image side compared to the first focusing lens group GF1, which moves along the optical axis along a different trajectory than the first focusing lens group GF1 during focusing.

[0048] Under the above structure, the zoom optical system ZL of this embodiment satisfies the following conditional equations (1) and (2).

[0049] -0.37 <fFs / fFy<0.37…(1)

[0050] 2.00 <f1 / fw<8.00…(2)

[0051] Wherein, fFs: the focal length of the focusing lens group with the strongest optical power among the focusing lens groups included in the subsequent lens group GR.

[0052] fFy: The focal length of the weakest focusing lens group within the subsequent lens group GR.

[0053] f1: Focal length of the front lens group GA

[0054] fw: Focal length of the zoom optical system ZL in wide-angle mode.

[0055] According to this embodiment, a zoom optical system with minimal aberration variation during focusing and an optical device equipped with such a zoom optical system can be obtained. Furthermore, since the subsequent lens group GR has multiple focusing lens groups, it is not necessary to make the focusing lens group large, thus suppressing variations in various aberrations, primarily spherical aberration, during focusing. Additionally, by varying the spacing between adjacent lens groups during zooming, aberration correction during zooming can be performed effectively.

[0056] The zoom optical system ZL in this embodiment can also be... Figure 4 The zoom optical system ZL(2) shown can also be Figure 7 The zoom optical system ZL(3) shown can also be Figure 10 The zoom optical system ZL(4) shown is an example. Alternatively, the zoom optical system ZL in this embodiment could also be... Figure 13 The zoom optical system ZL(5) shown can also be Figure 16 The zoom optical system ZL(6) shown can also be Figure 19 The zoom optical system ZL(7) is shown.

[0057] Condition (1) specifies an appropriate relationship between the focal length of the focusing lens group with the strongest optical power among the focusing lens groups included in the subsequent lens group GR and the focal length of the focusing lens group with the weakest optical power among the focusing lens groups included in the subsequent lens group GR. By satisfying condition (1), variations in various aberrations, primarily spherical aberration, can be suppressed during focusing.

[0058] When the corresponding value of conditional expression (1) is higher than the upper limit, the difference in optical power between the focusing lens group with the strongest optical power and the focusing lens group with the weakest optical power becomes smaller, making it difficult to suppress the variation of various aberrations, primarily spherical aberration, during focusing. By setting the upper limit of conditional expression (1) to 0.35, 0.30, 0.28, 0.26, 0.20, 0.18, and further setting it to 0.15, the effect of this embodiment can be obtained more reliably.

[0059] When the corresponding value of conditional expression (1) is lower than the lower limit, the difference in optical power between the focusing lens group with the strongest optical power and the focusing lens group with the weakest optical power also becomes smaller, making it difficult to suppress the variation of various aberrations, primarily spherical aberration, during focusing. By setting the lower limit of conditional expression (1) to -0.35, -0.30, -0.25, -0.20, -1.50, -1.00, -0.50, and -0.30, and further setting it to -0.10, the effect of this embodiment can be obtained more reliably.

[0060] Condition (2) specifies the appropriate relationship between the focal length of the front lens group GA and the focal length of the zoom optical system ZL in the wide-angle state. By satisfying condition (2), the variation of various aberrations, primarily spherical aberration, can be suppressed during zooming without making the lens barrel larger.

[0061] When the corresponding value of conditional expression (2) is higher than the upper limit value, the optical power of the front lens group GA becomes weaker, and therefore the amount of movement of the front lens group GA during magnification increases, resulting in a larger lens barrel. By setting the upper limit value of conditional expression (2) to 7.80, 7.50, 7.40, 7.00, 6.50, 6.30, and further setting it to 6.00, the effects of this embodiment can be obtained more reliably.

[0062] When the corresponding value of conditional expression (2) is lower than the lower limit, the optical power of the front lens group GA becomes stronger, making it difficult to suppress the changes in various aberrations, primarily spherical aberration, during zoom. By setting the lower limit of conditional expression (2) to 2.30, 2.50, 2.80, 3.00, 3.30, 3.50, and further setting it to 3.80, the effects of this embodiment can be obtained more reliably.

[0063] The zoom optical system ZL in this embodiment preferably satisfies the following condition (3).

[0064] -6.00 <fFs / fw<6.00…(3)

[0065] Condition (3) specifies the appropriate relationship between the focal length of the focusing lens group with the strongest optical power among the focusing lens groups included in the subsequent lens group GR and the focal length of the zoom optical system ZL in the wide-angle end state. By satisfying condition (3), it is possible to suppress the variation of various aberrations, primarily spherical aberration, during focusing.

[0066] When the corresponding value of conditional expression (3) is higher than the upper limit, the difference in optical power between the focusing lens group with the strongest optical power and the focusing lens group with the weakest optical power becomes smaller, making it difficult to suppress the variation of various aberrations, primarily spherical aberration, during focusing. By setting the upper limit of conditional expression (3) to 5.50, 5.00, 4.80, 4.50, 4.00, and further setting it to 3.80, the effect of this embodiment can be obtained more reliably.

[0067] When the corresponding value of conditional expression (3) is lower than the lower limit, the optical power of the focusing lens group with the strongest optical power becomes stronger, making it difficult to suppress the variation of various aberrations, primarily spherical aberration, during focusing. By setting the lower limit of conditional expression (3) to -5.50, -5.00, -4.50, -4.00, -3.50, -3.00, -2.50, -2.00, and further setting it to -1.80, the effect of this embodiment can be obtained more reliably.

[0068] The zoom optical system ZL in this embodiment preferably satisfies the following condition (4).

[0069] 4.30 <f1 / (-fM1w)<10.00…(4)

[0070] Where fM1w: the focal length of the first intermediate lens group GM1 in the wide-angle state.

[0071] Condition (4) specifies the appropriate relationship between the focal length of the front lens group GA and the focal length of the first intermediate lens group GM1 in the wide-angle state. By satisfying condition (4), it is possible to suppress the variation of various aberrations, primarily spherical aberration, during zoom.

[0072] When the corresponding value of conditional expression (4) is higher than the upper limit value, the optical power of the first intermediate lens group GM1 becomes stronger, making it difficult to suppress the changes in various aberrations, primarily spherical aberration, during zooming. By setting the upper limit value of conditional expression (4) to 9.50, 9.00, 8.80, 8.50, 8.30, 8.00, and further setting it to 7.80, the effects of this embodiment can be obtained more reliably.

[0073] When the corresponding value of condition (4) is lower than the lower limit, the optical power of the front lens group GA becomes stronger, making it difficult to suppress the changes in various aberrations, primarily spherical aberration, during zoom. By setting the lower limit of condition (4) to 4.50, 4.80, 5.00, and further setting it to 5.40, the effect of this embodiment can be obtained more reliably.

[0074] In the zoom optical system ZL of this embodiment, it is preferable that the second intermediate lens group GM2 includes at least two lens groups with positive optical power, and the zoom optical system ZL satisfies the following condition (5).

[0075] 1.50 <f1 / fM21<7.00…(5)

[0076] Wherein, fM21: the focal length of the lens group closest to the object in the lens group included in the second intermediate lens group GM2.

[0077] Condition (5) specifies an appropriate relationship between the focal length of the front lens group GA and the focal length of the lens group closest to the object in the second intermediate lens group GM2. By satisfying condition (5), variations in aberrations, primarily spherical aberration, during focusing can be suppressed.

[0078] When the corresponding value of conditional expression (5) is higher than the upper limit value, the optical power of the lens group closest to the object in the lens group included in the second intermediate lens group GM2 becomes stronger, making it difficult to suppress the variation of various aberrations, primarily spherical aberration, during focusing. By setting the upper limit value of conditional expression (5) to 6.80, 6.50, 6.30, 6.00, 5.80, 5.00, 4.50, 4.00, and further setting it to 3.50, the effect of this embodiment can be obtained more reliably.

[0079] When the corresponding value of conditional expression (5) is lower than the lower limit, the optical power of the front lens group GA becomes stronger, making it difficult to suppress the variation of various aberrations, primarily spherical aberration, during focusing. By setting the lower limit of conditional expression (5) to 1.60, 1.80, 2.00, 2.10, and further setting it to 2.20, the effect of this embodiment can be obtained more reliably.

[0080] The zoom optical system ZL in this embodiment preferably satisfies the following condition (6).

[0081] 0.10 <BFw / fw<1.00…(6)

[0082] Wherein, BFw: the back focal length of the zoom optical system ZL in wide-angle mode.

[0083] Condition (6) specifies the appropriate relationship between the back focal length of the zoom optical system ZL in the wide-angle state and the focal length of the zoom optical system ZL in the wide-angle state. By satisfying condition (6), various aberrations, primarily coma, can be well corrected in the wide-angle state.

[0084] When the corresponding value of conditional expression (6) is higher than the upper limit value, the back focal length of the zoom optical system ZL in the wide-angle state becomes larger than that in the wide-angle state, making it difficult to correct various aberrations, primarily coma, in the wide-angle state. By setting the upper limit value of conditional expression (6) to 0.95, 0.90, 0.85, 0.80, 0.75, 0.70, 0.65, and further setting it to 0.60, the effects of this embodiment can be obtained more reliably.

[0085] When the corresponding value of conditional expression (6) is lower than the lower limit, the back focal length of the zoom optical system ZL in the wide-angle state becomes smaller than that in the wide-angle state, making it difficult to correct various aberrations, primarily coma, in the wide-angle state. Furthermore, it becomes difficult to configure the mechanical components of the lens barrel. By setting the lower limit of conditional expression (6) to 0.15, 0.20, 0.25, 0.30, 0.35, 0.40, and further to 0.43, the effects of this embodiment can be obtained more reliably.

[0086] The zoom optical system ZL in this embodiment preferably satisfies the following condition (7).

[0087] 0.20<|fFs| / f1<2.00…(7)

[0088] Condition (7) specifies an appropriate relationship between the focal length of the focusing lens group with the strongest optical power among the focusing lens groups included in the subsequent lens group GR and the focal length of the front lens group GA. By satisfying condition (7), it is possible to suppress variations in various aberrations, primarily spherical aberration, during focusing without making the lens barrel larger. In addition, it is possible to suppress variations in various aberrations, primarily spherical aberration, during zoom without making the lens barrel larger.

[0089] When the corresponding value of conditional expression (7) is higher than the upper limit value, the optical power of the focusing lens group weakens, thus increasing the amount of movement of the focusing lens group during focusing and making the lens barrel larger. In addition, the optical power of the front lens group GA becomes stronger, making it difficult to suppress the changes in various aberrations, primarily spherical aberration, during zoom. By setting the upper limit value of conditional expression (7) to 1.80, 1.50, 1.30, 1.00, 0.85, 0.70, 0.65, 0.60, and further setting it to 0.58, the effects of this embodiment can be obtained more reliably.

[0090] When the corresponding value of conditional expression (7) is lower than the lower limit, the optical power of the focusing lens group becomes stronger, making it difficult to suppress the variation of various aberrations, primarily spherical aberration, during focusing. Furthermore, the optical power of the front lens group GA becomes weaker, resulting in a larger movement of the front lens group GA during zooming and a larger lens barrel. By setting the lower limit of conditional expression (7) to 0.22, 0.24, 0.25, and further to 0.26, the effects of this embodiment can be obtained more reliably.

[0091] The zoom optical system ZL in this embodiment preferably satisfies the following condition (8).

[0092] 1.50<|fFs| / (-fM1w)<5.00…(8)

[0093] Where fM1w: the focal length of the first intermediate lens group GM1 in the wide-angle state.

[0094] Condition (8) specifies an appropriate relationship between the focal length of the focusing lens group with the strongest optical power among the focusing lens groups included in the subsequent lens group GR, and the focal length of the first intermediate lens group GM1 in the wide-angle state. By satisfying condition (8), variations in various aberrations, primarily spherical aberration, during focusing can be suppressed. In addition, various aberrations, primarily coma, in the wide-angle state can be well corrected.

[0095] When the corresponding value of conditional expression (8) is higher than the upper limit value, the optical power of the first intermediate lens group GM1 in the wide-angle state becomes stronger, making it difficult to correct various aberrations, primarily coma, in the wide-angle state. By setting the upper limit value of conditional expression (8) to 4.85, 4.70, 4.50, 4.35, 4.25, 3.85, 3.50, 3.00, and further setting it to 2.50, the effects of this embodiment can be obtained more reliably.

[0096] When the corresponding value of conditional expression (8) is lower than the lower limit, the optical power of the focusing lens group becomes stronger, making it difficult to suppress the variation of various aberrations, primarily spherical aberration, during focusing. By setting the lower limit of conditional expression (8) to 1.55, 1.60, 1.65, 1.70, 1.75, 1.80, and further setting it to 1.83, the effect of this embodiment can be obtained more reliably.

[0097] The zoom optical system ZL in this embodiment preferably satisfies the following condition (9).

[0098] 0.90<|fFs| / fM2w<4.00…(9)

[0099] Where fM2w: the focal length of the second intermediate lens group GM2 in the wide-angle state.

[0100] Condition (9) specifies an appropriate relationship between the focal length of the focusing lens group with the strongest optical power among the focusing lens groups included in the subsequent lens group GR, and the focal length of the second intermediate lens group GM2 in the wide-angle state. By satisfying condition (9), variations in various aberrations, primarily spherical aberration, during focusing can be suppressed. In addition, various aberrations, primarily coma, in the wide-angle state can be well corrected.

[0101] When the corresponding value of conditional expression (9) is higher than the upper limit value, the optical power of the second intermediate lens group GM2 in the wide-angle state becomes stronger, making it difficult to correct various aberrations, primarily coma, in the wide-angle state. By setting the upper limit value of conditional expression (9) to 3.80, 3.50, 3.30, 3.00, 2.80, 2.60, 2.00, 1.80, and further setting it to 1.50, the effects of this embodiment can be obtained more reliably.

[0102] When the corresponding value of conditional expression (9) is lower than the lower limit, the optical power of the focusing lens group becomes stronger, making it difficult to suppress the variation of various aberrations, primarily spherical aberration, during focusing. By setting the lower limit of conditional expression (9) to 0.95, 0.98, 1.00, 1.03, and further setting it to 1.05, the effect of this embodiment can be obtained more reliably.

[0103] The zoom optical system ZL in this embodiment preferably satisfies the following condition (10).

[0104] 0.20 <f1 / (-fRw)<5.00…(10)

[0105] Where fRw: the focal length of the subsequent lens group GR in the wide-angle state.

[0106] Condition (10) specifies the appropriate relationship between the focal length of the front lens group GA and the focal length of the subsequent lens group GR in the wide-angle state. By satisfying condition (10), various aberrations, primarily coma, can be well corrected in the wide-angle state without making the lens barrel larger.

[0107] When the corresponding value of conditional expression (10) is higher than the upper limit, the optical power of the subsequent lens group GR in the wide-angle state becomes stronger, making it difficult to correct various aberrations, primarily coma, in the wide-angle state. Furthermore, the optical power of the front lens group GA becomes weaker, resulting in a larger movement of the front lens group GA during zooming and a larger lens barrel. By setting the upper limit of conditional expression (10) to 4.50, 4.00, 3.80, 3.50, 3.30, 3.00, 2.80, and further to 2.50, the effects of this embodiment can be obtained more reliably.

[0108] When the corresponding value of conditional expression (10) is lower than the lower limit, the optical power of the subsequent lens group GR in the wide-angle state becomes weak, making it difficult to correct various aberrations, primarily coma, in the wide-angle state. By setting the lower limit of conditional expression (10) to 0.40, 0.50, 0.60, 0.65, 0.68, and further setting it to 0.70, the effects of this embodiment can be obtained more reliably.

[0109] The zoom optical system ZL in this embodiment preferably satisfies the following condition (11).

[0110] 0.10 <MTF1 / MTF2<3.00…(11)

[0111] Wherein, MTF1: the absolute value of the amount of movement of the first focusing lens group GF1 when focusing from an object at infinity to a closer object in the telephoto state.

[0112] MTF2: The absolute value of the movement of the closest focusing lens group (GF1) among the other focusing lens groups when focusing from an object at infinity to a closer object in the telephoto end state.

[0113] Condition (11) specifies the appropriate relationship between the amount of movement of the first focusing lens group GF1 and the amount of movement of the focusing lens group closest to the first focusing lens group GF1 when focusing from an object at infinity to a closer object in the telephoto state. By satisfying condition (11), it is possible to suppress the variation of various aberrations, primarily spherical aberration, when focusing from an object at infinity to a closer object in the telephoto state.

[0114] When the corresponding value of conditional expression (11) is higher than the upper limit value, when focusing from an object at infinity to a closer object in the telephoto state, the movement of the first focusing lens group GF1 becomes too large, making it difficult to suppress the variation of various aberrations, primarily spherical aberration. By setting the upper limit value of conditional expression (11) to 2.80, 2.50, 2.30, 2.00, 1.80, 1.65, and further setting it to 1.50, the effect of this embodiment can be obtained more reliably.

[0115] When the corresponding value of conditional expression (11) is lower than the lower limit, when focusing from an object at infinity to a closer object in the telephoto state, the movement of the focusing lens group closest to the first focusing lens group GF1 becomes too large, making it difficult to suppress the variation of various aberrations, primarily spherical aberration. By setting the lower limit of conditional expression (11) to 0.13, 0.15, 0.18, 0.20, 0.23, and further setting it to 0.25, the effect of this embodiment can be obtained more reliably.

[0116] The zoom optical system ZL in this embodiment preferably satisfies the following condition (12).

[0117] 0.10 < βF1w / βF2w < 3.00…(12)

[0118] Wherein, βF1w: the composite lateral magnification of the focusing lens group included in the subsequent lens group GR when focusing on an infinity object at the wide-angle end compared to the focusing lens group on the object side closest to the image side.

[0119] βF2w: Lateral magnification when focusing on an infinity object at the wide-angle end of the focusing lens group (the one closest to the image side) within the subsequent lens group GR.

[0120] Condition (12) specifies an appropriate relationship between the lateral magnification of the focusing lens group closest to the image side in the wide-angle end of the subsequent lens group GR when focusing on an infinity object, and the combined lateral magnification of the focusing lens group located on the object side in the wide-angle end of the same lens group. By satisfying condition (12), variations in aberrations, primarily spherical aberration, can be suppressed when focusing from an infinity object to a closer object in the wide-angle end.

[0121] When the corresponding value of conditional expression (12) is higher than the upper limit, the combined lateral magnification becomes excessive when focusing on an infinity object in the wide-angle end state compared to the focusing lens group on the object side, which is closest to the image side. Therefore, it is difficult to suppress the variation of various aberrations, primarily spherical aberration, when focusing from an infinity object to a close object in the wide-angle end state. By setting the upper limit of conditional expression (12) to 2.80, 2.50, 2.30, 2.00, 1.80, 1.50, 1.30, 1.00, and further setting it to 0.90, the effect of this embodiment can be obtained more reliably.

[0122] When the corresponding value of conditional expression (12) is lower than the lower limit, the lateral magnification becomes excessive when focusing on an infinity object in the wide-angle state of the focusing lens group closest to the image side. Therefore, it is difficult to suppress the variation of various aberrations, primarily spherical aberration, when focusing from an infinity object to a close object in the wide-angle state. By setting the lower limit of conditional expression (12) to 0.20, 0.35, 0.50, 0.55, 0.58, and further setting it to 0.60, the effect of this embodiment can be obtained more reliably.

[0123] The zoom optical system ZL in this embodiment preferably satisfies the following condition (13).

[0124] 0.10 < βF1t / βF2t < 3.00…(13)

[0125] Wherein, βF1t: the composite lateral magnification at the far focal end of the focusing lens group included in the subsequent lens group GR, when focusing on an infinity object compared to the focusing lens group located on the object side of the focusing lens group closest to the image side.

[0126] βF2t: Lateral magnification when focusing on an infinity object at the far focal end of the focusing lens group (the one closest to the image side) within the subsequent lens group GR.

[0127] Condition (13) specifies an appropriate relationship between the lateral magnification of the most image-side focusing lens group in the subsequent lens group GR when focusing on an infinity object at the far focal end and the combined lateral magnification of the most image-side focusing lens group when focusing on an infinity object at the far focal end compared to the object-side focusing lens group. By satisfying condition (13), variations in aberrations, primarily spherical aberration, can be suppressed when focusing from an infinity object to a closer object at the far focal end.

[0128] When the corresponding value of conditional expression (13) is higher than the upper limit, the combined lateral magnification becomes excessive when focusing on an infinity object at the far focal end compared to the focusing lens group located on the object side, which is the closest to the image side. Therefore, it is difficult to suppress the variation of various aberrations, primarily spherical aberration, when focusing from an infinity object to a close object at the far focal end. By setting the upper limit of conditional expression (13) to 2.80, 2.50, 2.30, 2.00, 1.80, 1.50, 1.30, 1.00, and further setting it to 0.80, the effect of this embodiment can be obtained more reliably.

[0129] When the corresponding value of conditional expression (13) is lower than the lower limit, the lateral magnification becomes excessive when focusing on an infinity object in the far-focus state of the focusing lens group closest to the image side. Therefore, it is difficult to suppress the variation of various aberrations, primarily spherical aberration, when focusing from an infinity object to a close-range object in the far-focus state. By setting the lower limit of conditional expression (13) to 0.13, 0.15, 0.18, 0.20, 0.23, and further setting it to 0.25, the effect of this embodiment can be obtained more reliably.

[0130] The zoom optical system ZL in this embodiment preferably satisfies the following condition (14).

[0131] 0.50 < βF1w < 2.60…(14)

[0132] Wherein, βF1w: the composite lateral magnification of the focusing lens group included in the subsequent lens group GR when focusing on an infinity object at the wide-angle end compared to the focusing lens group on the object side closest to the image side.

[0133] Condition (14) specifies an appropriate range for the combined lateral magnification of the focusing lens group at the wide-angle end of the focusing lens group included in the subsequent lens group GR, which is located on the object side compared to the focusing lens group closest to the image side. By satisfying condition (14), variations in various aberrations, primarily spherical aberration and coma, can be suppressed during focusing.

[0134] When the corresponding value of conditional expression (14) is higher than the upper limit value, it is difficult to suppress the variation of various aberrations during focusing. By setting the upper limit value of conditional expression (14) to 2.58, 2.55, 2.00, 1.80, 1.50, 1.30, and further setting it to 1.20, the effect of this embodiment can be obtained more reliably.

[0135] When the corresponding value of conditional expression (14) is lower than the lower limit, it is difficult to suppress the variation of various aberrations during focusing. By setting the lower limit of conditional expression (14) to 0.55, 0.60, 0.65, 0.70, and further setting it to 0.73, the effect of this embodiment can be obtained more reliably.

[0136] The zoom optical system ZL in this embodiment preferably satisfies the following condition (15).

[0137] 0.20 < βF2w < 1.80…(15)

[0138] Wherein, βF2w: the lateral magnification of the focusing lens group (the one closest to the image side) at the wide-angle end when focusing on an infinity object within the subsequent lens group GR.

[0139] Condition (15) specifies an appropriate range for the lateral magnification of the focusing lens group closest to the image side in the wide-angle end state of the subsequent lens group GR when focusing on an infinity object. By satisfying condition (15), it is possible to suppress variations in various aberrations, primarily spherical aberration and coma, during focusing.

[0140] When the corresponding value of conditional expression (15) is higher than the upper limit value, it is difficult to suppress the variation of various aberrations during focusing. By setting the upper limit value of conditional expression (15) to 1.78, 1.75, 1.73, 1.70, 1.68, and further setting it to 1.60, the effect of this embodiment can be obtained more reliably.

[0141] When the corresponding value of conditional expression (15) is lower than the lower limit, it is difficult to suppress the variation of various aberrations during focusing. By setting the lower limit of conditional expression (15) to 0.23, 0.25, and further to 0.28, the effect of this embodiment can be obtained more reliably.

[0142] The zoom optical system ZL in this embodiment preferably satisfies the following condition (16).

[0143] {βF1w+(1 / βF1w)} -2 ≤0.25…(16)

[0144] Wherein, βF1w: the composite lateral magnification of the focusing lens group included in the subsequent lens group GR when focusing on an infinity object at the wide-angle end compared to the focusing lens group on the object side closest to the image side.

[0145] Condition (16) specifies an appropriate range for the combined lateral magnification of the focusing lens group at the wide-angle end of the focusing lens group included in the subsequent lens group GR, which is located on the object side compared to the focusing lens group closest to the image side. By satisfying condition (16), variations in various aberrations, primarily spherical aberration and coma, can be suppressed during focusing. When the corresponding value of condition (16) is higher than the upper limit, it is difficult to suppress variations in various aberrations during focusing.

[0146] The zoom optical system ZL in this embodiment preferably satisfies the following condition (17).

[0147] {βF2w+(1 / βF2w)} -2 ≤0.25…(17)

[0148] Wherein, βF2w: the lateral magnification of the focusing lens group (the one closest to the image side) at the wide-angle end when focusing on an infinity object within the subsequent lens group GR.

[0149] Condition (17) specifies an appropriate range for the lateral magnification of the focusing lens group closest to the image side in the wide-angle end state of the subsequent lens group GR when focusing on an infinity object. By satisfying condition (17), variations in aberrations, primarily spherical aberration and coma, during focusing can be suppressed. When the corresponding value of condition (17) is higher than the upper limit, it is difficult to suppress variations in aberrations during focusing.

[0150] In the zoom optical system ZL of this embodiment, it is preferable that the subsequent lens group GR includes at least one lens group disposed on the image side compared to the focusing lens group included in the subsequent lens group GR. This effectively suppresses variations in various aberrations, primarily spherical aberration, during focusing.

[0151] The zoom optical system ZL in this embodiment preferably satisfies the following condition (18).

[0152] 0.10 < |fFs| / |fRF| < 4.00…(18)

[0153] Wherein, fRF: the focal length of the lens group in the at least one lens group that is arranged adjacent to the image side of the focusing lens group closest to the image side.

[0154] Condition (18) specifies an appropriate relationship between the focal length of the focusing lens group with the strongest optical power among the focusing lens groups included in the subsequent lens group GR and the focal length of the lens group arranged adjacent to the image side of the focusing lens group closest to the image side. By satisfying condition (18), variations in various aberrations, primarily spherical aberration, during focusing can be suppressed.

[0155] When the corresponding value of conditional expression (18) is higher than the upper limit value, the optical power of the lens group arranged adjacent to the image side of the focusing lens group closest to the image side becomes stronger, making it difficult to suppress the variation of various aberrations, primarily spherical aberration, during focusing. By setting the upper limit value of conditional expression (18) to 3.80, 3.50, 3.30, 3.00, 2.80, 2.50, 2.30, 2.00, 1.50, 1.30, and further setting it to 1.00, the effect of this embodiment can be obtained more reliably.

[0156] When the corresponding value of conditional expression (18) is lower than the lower limit, the optical power of the focusing lens group becomes stronger, making it difficult to suppress the variation of various aberrations, primarily spherical aberration, during focusing. By setting the lower limit of conditional expression (18) to 0.13, 0.15, and further to 0.18, the effect of this embodiment can be obtained more reliably.

[0157] The zoom optical system ZL in this embodiment preferably satisfies the following condition (19).

[0158] 2ωw>75.0°…(19)

[0159] Wherein, 2ωw: the full field of view of the zoom optical system ZL in the wide-angle state.

[0160] Condition (19) specifies an appropriate range for the full field of view of the zoom optical system ZL in the wide-angle state. By satisfying condition (19), a zoom optical system with a wide field of view can be obtained, which is therefore preferred. By setting the lower limit of condition (19) to 78.0°, 80.0°, and further to 83.0°, the effects of this embodiment can be obtained more reliably.

[0161] The zoom optical system ZL in this embodiment preferably satisfies the following condition (20).

[0162] ft / fw>3.50…(20)

[0163] Where ft: the focal length of the zoom optical system ZL in the telephoto state.

[0164] Condition (20) specifies an appropriate relationship between the focal length of the zoom optical system ZL in the telephoto end state and the focal length of the zoom optical system ZL in the wide-angle end state. By satisfying condition (20), a zoom optical system with a high zoom ratio can be obtained, which is therefore preferred. By setting the lower limit value of condition (20) to 3.80, 4.00, 4.20, and further setting it to 4.40, the effects of this embodiment can be obtained more reliably.

[0165] The zoom optical system ZL in this embodiment preferably satisfies the following condition (21).

[0166] 0.10 < (-fN) / fL < 1.00…(21)

[0167] Wherein, fN: the focal length of the lens in the zoom optical system ZL, which is the second lens from the image side.

[0168] fL: The focal length of the lens closest to the image side in the zoom optical system ZL configuration.

[0169] Condition (21) specifies the appropriate relationship between the focal length of the second lens of the zoom optical system ZL located from the image side and the focal length of the lens of the zoom optical system ZL located closest to the image side. By satisfying condition (21), it is possible to effectively correct various aberrations, primarily coma, in the wide-angle state.

[0170] When the corresponding value of conditional expression (21) is higher than the upper limit value, the optical power of the lens of the zoom optical system ZL located on the image side becomes stronger, making it difficult to correct various aberrations, primarily coma, in the wide-angle state. By setting the upper limit value of conditional expression (21) to 0.95, 0.90, 0.85, 0.83, 0.80, 0.78, 0.75, 0.73, and further setting it to 0.70, the effects of this embodiment can be obtained more reliably.

[0171] When the corresponding value of conditional expression (21) is lower than the lower limit, the optical power of the lens in the second position from the image side of the zoom optical system ZL becomes stronger, making it difficult to correct various aberrations, primarily coma, in the wide-angle state. By setting the lower limit of conditional expression (21) to 0.13, 0.15, and further to 0.18, the effects of this embodiment can be obtained more reliably.

[0172] Next, refer to Figure 23The manufacturing method of the aforementioned zoom optical system ZL is summarized below. First, a front lens group GA with positive optical power, a first intermediate lens group GM1 with negative optical power, a second intermediate lens group GM2 with positive optical power, and a subsequent lens group GR are arranged sequentially along the optical axis from the object side (step ST1). Next, the spacing between adjacent lens groups changes during zooming (step ST2). Next, a first focusing lens group GF1 that moves along the optical axis during focusing is arranged at the object side of the subsequent lens group GR, and at least one other focusing lens group in the subsequent lens group GR that moves along the optical axis along a different trajectory than the first focusing lens group GF1 during focusing is arranged at the image side of the subsequent lens group GR (step ST3). Furthermore, each lens is arranged in the lens barrel in a manner that at least satisfies the above-described conditions (1) and (2) (step ST4). According to the manufacturing method described above, a zoom optical system with minimal aberration during focusing can be manufactured.

[0173] Example

[0174] Hereinafter, the zoom optical system ZL of this embodiment will be described with reference to the accompanying drawings. Figure 1 , Figure 4 , Figure 7 , Figure 10 , Figure 13 , Figure 16 , Figure 19 This is a cross-sectional view showing the structure and optical power distribution of the zoom optical system ZL{ZL(1)~ZL(7)} in embodiments 1 to 7. In the cross-sectional views of the zoom optical systems ZL(1)~ZL(7) in embodiments 1 to 7, arrows are used along with the word "focus" to indicate the direction of movement of the focusing group along the optical axis when focusing from infinity to a close object. In the cross-sectional views of the zoom optical systems ZL(1)~ZL(7) in embodiments 1 to 7, arrows are used to indicate the direction of movement of each lens group along the optical axis when zooming from the wide-angle end state (W) to the telephoto end state (T).

[0175] In these Figure 1 , Figure 4 , Figure 7 , Figure 10 , Figure 13 , Figure 16 , Figure 19 In this embodiment, lens groups are represented by a combination of the symbol G and numbers, and individual lenses are represented by a combination of the symbol L and numbers. To prevent excessive complexity due to the large number of types and digits of symbols and numbers, a separate combination of symbols and numbers is used to represent lens groups, etc., for each embodiment. Therefore, even if the same combination of symbols and numbers is used across embodiments, it does not necessarily mean that they are identical structures.

[0176] Tables 1 through 7 are shown below. Table 1 represents the parameter data in the first embodiment, Table 2 represents the parameter data in the second embodiment, Table 3 represents the parameter data in the third embodiment, Table 4 represents the parameter data in the fourth embodiment, Table 5 represents the parameter data in the fifth embodiment, Table 6 represents the parameter data in the sixth embodiment, and Table 7 represents the parameter data in the seventh embodiment. In each embodiment, the d-line (wavelength λ = 587.6 nm) and the g-line (wavelength λ = 435.8 nm) are selected as the objects for calculating aberration characteristics.

[0177] In the [Overall Parameters] table, f represents the focal length of the entire lens system, FNO represents the F-number, 2ω represents the field of view (in degrees, ω is the half field of view), and Ymax represents the maximum image height. TL represents the distance along the optical axis from the front of the lens to the rear surface of the lens when focusing at infinity, plus the distance BF. BF represents the distance along the optical axis from the rear surface of the lens to the image plane I when focusing at infinity (back focal length). Furthermore, these values ​​are shown separately for each zoom level at the wide-angle (W) and telephoto (T) ends.

[0178] Additionally, in the [Overall Parameters] table, fM1w represents the focal length of the first intermediate lens group in the wide-angle state. fM2w represents the focal length of the second intermediate lens group in the wide-angle state. MTF1 represents the absolute value of the movement of the first focusing lens group when focusing from an infinity object to a near object in the telephoto state. MTF2 represents the absolute value of the movement of the focusing lens group closest to the first focusing lens group among the other focusing lens groups when focusing from an infinity object to a near object in the telephoto state. βF1w represents the combined lateral magnification when focusing on an infinity object in the wide-angle state compared to the focusing lens group on the object side of the focusing lens group included in the subsequent lens groups. βF2w represents the lateral magnification when focusing on an infinity object in the wide-angle state of the focusing lens group on the image side of the focusing lens group included in the subsequent lens groups. βF1t represents the combined lateral magnification at the telephoto end of the focusing lens group within the subsequent lens group, specifically the focusing lens group located on the object side compared to the image-side focusing lens group. βF2t represents the lateral magnification at the telephoto end of the focusing lens group within the subsequent lens group, specifically the focusing lens group on the image side. fN represents the focal length of the second lens in the zoom optical system, counted from the image side. fL represents the focal length of the lens in the zoom optical system, located on the image side. fRw represents the focal length of the subsequent lens group in the wide-angle end.

[0179] In the [Lens Parameters] table, the surface number indicates the order of the optical surfaces from the object side along the direction of light travel. R represents the radius of curvature of each optical surface (the surface with the center of curvature on the image side is positive). D represents the distance on the optical axis from each optical surface to the next optical surface (or image surface), i.e., the surface spacing. nd represents the refractive index of the optical component material with respect to the d-line, and νd represents the Abbe number of the optical component material with respect to the d-line. "∞" for radius of curvature indicates a plane or opening, and (aperture S) indicates the aperture stop S. The refractive index of air, nd = 1.00000, is omitted. When the optical surface is aspherical, an asterisk (*) is added to the surface number, and the paraxial radius of curvature is shown in the radius of curvature R column.

[0180] In the [Aspherical Data] table, the shape of the aspherical surface shown in [Lens Parameters] is represented by the following formula (A). X(y) represents the distance (recession) along the optical axis from the tangent at the vertex of the aspherical surface to the position on the aspherical surface at height y, R represents the radius of curvature of the reference sphere (paraxial radius of curvature), κ represents the conic constant, and Ai represents the aspherical coefficient of the i-th order. "En" indicates "×10 -n For example, 1.234E-05 = 1.234 × 10 -5 Additionally, the quadratic aspheric coefficient A2 is 0, so its description is omitted.

[0181] X(y)=(y 2 / R) / {1+(1-κ×y 2 / R 2 ) 1 / 2}+A4×y 4 +A6×y 6 +A8×y 8 +A10×y 10

[0182] …(A)

[0183] The [Variable Interval Data] table shows the surface interval at surface number i where the surface interval is (Di) within the [Lens Parameters] table. Additionally, the [Variable Interval Data] table shows the surface interval for infinity focusing and close-range focusing.

[0184] The table in [Lens Group Data] shows the initial plane (the plane closest to the object) and focal length of each lens group.

[0185] In all parameter values ​​below, the focal length f, radius of curvature R, interplanar spacing D, and other lengths will generally be expressed in "mm" unless otherwise specified. However, the same optical performance can be obtained even if the optical system is scaled up or down proportionally, so it is not limited to this.

[0186] The descriptions of the tables up to this point are the same in all embodiments, and repeated descriptions are omitted below.

[0187] (First Embodiment)

[0188] use Figures 1-3 Table 1 describes the first embodiment. Figure 1 This is a diagram showing the lens structure of the zoom optical system of the first embodiment. The zoom optical system ZL(1) of the first embodiment consists of a first lens group with positive optical power arranged sequentially along the optical axis from the object side.

[0189] The system comprises a second lens group (G1) with negative optical power, a third lens group (G3) with positive optical power, a fourth lens group (G4) with positive optical power, a fifth lens group (G5) with negative optical power, a sixth lens group (G6) with negative optical power, and a seventh lens group (G7) with positive optical power. When zooming from the wide-angle end (W) to the telephoto end (T), lens groups G1 to G7 move along the optical axis towards the object side, and the spacing between adjacent lens groups changes. An aperture stop (S) is positioned between the second lens group (G2) and the third lens group (G3). During zooming, the aperture stop (S) moves along the optical axis together with the third lens group (G3). The symbols (+) or (-) attached to each lens group indicate the optical power of each lens group, which is the same in all the following embodiments.

[0190] The first lens group G1 consists of a positive lens consisting of a negative meniscus lens L11 with its convex surface facing the object side and a positive meniscus lens L12 with its convex surface facing the object side, arranged sequentially along the optical axis from the object side, and a positive meniscus lens L13 with its convex surface facing the object side.

[0191] The second lens group G2 consists of a positive lens consisting of a negative meniscus lens L21 (convex side facing the object), a negative meniscus lens L22 (convex side facing the object), and a positive meniscus lens L23 (convex side facing the object), arranged sequentially along the optical axis from the object side, and a negative meniscus lens L24 (concave side facing the object). The object-side lens surface of the negative meniscus lens L21 is aspherical.

[0192] The third lens group G3 consists of a biconvex positive lens L31. The object-side lens surface of the positive lens L31 is aspherical.

[0193] The fourth lens group G4 consists of a positive lens arranged along the optical axis from the object side: a negative meniscus lens L41 (convex side facing the object) and a biconvex positive lens L42; a positive lens L43 (biconvex side) and a negative meniscus lens L44 (concave side facing the object); and a positive meniscus lens L45 (concave side facing the object). The object-side lens surface of the positive meniscus lens L45 is aspherical.

[0194] The fifth lens group G5 consists of a positive meniscus lens L51 with its concave surface facing the object side, arranged sequentially along the optical axis from the object side, and a biconcave negative lens L52.

[0195] Lens group G6 consists of a biconcave negative lens L61. The object-side lens surface of the negative lens L61 is aspherical.

[0196] The seventh lens group G7 consists of a positive meniscus lens L71 with its convex surface facing the object side. An image plane I is disposed on the image side of the seventh lens group G7.

[0197] In this embodiment, the first lens group G1 constitutes the front lens group GA with positive optical power. The second lens group G2 constitutes the first intermediate lens group GM1 with negative optical power. The third lens group G3 and the fourth lens group G4 together constitute the second intermediate lens group GM2 with positive optical power. The fifth lens group G5, the sixth lens group G6, and the seventh lens group G7 together constitute the subsequent lens group GR with negative optical power. When focusing from an object at infinity to a closer object, the fifth lens group G5 and the sixth lens group G6 constituting the subsequent lens group GR move along the optical axis to the image side with different trajectories (movement amounts). That is, the fifth lens group G5 is equivalent to the first focusing lens group GF1 of the subsequent lens group GR, which is located closest to the object. The sixth lens group G6 is equivalent to the other focusing lens group, namely the second focusing lens group GF2, which is located on the image side compared to the first focusing lens group GF1.

[0198] Table 1 below shows the values ​​of the parameters of the zoom optical system of the first embodiment.

[0199] (Table 1)

[0200] [Overall Parameters]

[0201]

[0202]

[0203] [Lens Parameters]

[0204]

[0205]

[0206] [Aspherical Data]

[0207] Page 6

[0208] κ=1.0000, A4=5.35995E-06, A6=-8.27153E-09, A8=2.12565E-11, A10=-2.60526E-14

[0209] Page 14

[0210] κ=1.0000, A4=-7.33442E-06, A6=4.81859E-09, A8=-4.26147E-11, A10=-2.53196E-14

[0211] Page 22

[0212] κ=1.0000, A4=-2.36052E-05, A6=6.01748E-09, A8=1.01789E-10, A10=1.24064E-13

[0213] Page 28

[0214] κ=1.0000, A4=-5.15978E-06, A6=-5.92439E-09, A8=4.45911E-12, A10=-6.10897E-15

[0215] [Variable Interval Data]

[0216]

[0217]

[0218] [Lens Group Data]

[0219]

[0220] Figure 2 (A) is a diagram of aberrations when focusing at infinity in the wide-angle end state of the zoom optical system of the first embodiment. Figure 2 (B) is a diagram of aberrations when focusing at infinity in the telephoto end state of the zoom optical system of the first embodiment. Figure 3 (A) is a diagram of aberrations during close-range focusing in the wide-angle end state of the zoom optical system of the first embodiment. Figure 3(B) is an aberration diagram of the zoom optical system of the first embodiment during close-range focusing at the telephoto end. In the aberration diagrams for focusing at infinity, FNO represents the F-value and Y represents the image height. In the aberration diagrams for focusing at close range, NA represents the numerical aperture and Y represents the image height. Additionally, the spherical aberration diagram shows the F-value or numerical aperture value corresponding to the maximum aperture, the astigmatism and distortion diagrams show the maximum image height values ​​respectively, and the coma diagram shows the values ​​of each image height. d represents the d-line (wavelength λ = 587.6 nm), and g represents the g-line (wavelength λ = 435.8 nm). In the astigmatism diagram, solid lines represent the sagittal image plane, and dashed lines represent the meridional image plane. Furthermore, the same symbols as in this embodiment are used in the aberration diagrams of the embodiments shown below, and repeated explanations are omitted.

[0221] As can be seen from the various aberration diagrams, the zoom optical system of the first embodiment can effectively correct various aberrations not only when focusing at infinity but also when focusing at close range, from the wide-angle end to the telephoto end, thus exhibiting excellent imaging performance.

[0222] (Second Embodiment)

[0223] use Figures 4-6 Table 2 illustrates the second embodiment. Figure 4 This is a diagram illustrating the lens structure of the zoom optical system of the second embodiment. The zoom optical system ZL(2) of the second embodiment consists of a first lens group G1 with positive optical power, a second lens group G2 with negative optical power, a third lens group G3 with positive optical power, a fourth lens group G4 with positive optical power, a fifth lens group G5 with positive optical power, a sixth lens group G6 with negative optical power, and a seventh lens group G7 with positive optical power, arranged sequentially along the optical axis from the object side. When zooming from the wide-angle end state (W) to the telephoto end state (T), the first to seventh lens groups G1 to G7 move along the optical axis towards the object side, and the spacing between adjacent lens groups changes. The aperture stop S is positioned between the second lens group G2 and the third lens group G3. During zooming, the aperture stop S moves together with the third lens group G3 along the optical axis.

[0224] The first lens group G1 consists of a positive lens consisting of a negative meniscus lens L11 with its convex surface facing the object side and a positive meniscus lens L12 with its convex surface facing the object side, arranged sequentially along the optical axis from the object side, and a positive meniscus lens L13 with its convex surface facing the object side.

[0225] The second lens group G2 consists of a negative meniscus lens L21 with its convex surface facing the object side, a positive lens consisting of a biconcave negative lens L22 and a biconvex positive lens L23 arranged sequentially along the optical axis from the object side, and a negative meniscus lens L24 with its concave surface facing the object side. The object-side lens surface of the negative meniscus lens L21 is aspherical.

[0226] The third lens group G3 consists of a positive meniscus lens L31 with its convex surface facing the object side, a biconvex positive lens L32, a negative meniscus lens L33 with its convex surface facing the object side, a combined positive lens of a biconvex positive lens L34 and a negative meniscus lens L35 with its concave surface facing the object side, arranged sequentially along the optical axis from the object side.

[0227] The fourth lens group G4 consists of a positive lens consisting of a negative meniscus lens L41 with its convex surface facing the object and a positive lens L42 with a biconvex shape.

[0228] The fifth lens group G5 consists of a combined positive lens consisting of a biconcave negative lens L51 and a biconvex positive lens L52 arranged sequentially along the optical axis from the object side, and a negative meniscus lens L53 with its concave surface facing the object side. The image-side lens surface of the negative meniscus lens L53 is aspherical.

[0229] Lens group G6 consists of a biconcave negative lens L61. The object-side lens surface of the negative lens L61 is aspherical.

[0230] The 7th lens group G7 is composed of a biconvex positive lens L71. An image plane I is arranged on the image side of the 7th lens group G7.

[0231] In this embodiment, the first lens group G1 constitutes the front lens group GA with positive optical power. The second lens group G2 constitutes the first intermediate lens group GM1 with negative optical power. The third lens group G3 and the fourth lens group G4 together constitute the second intermediate lens group GM2 with positive optical power. The fifth lens group G5, the sixth lens group G6, and the seventh lens group G7 together constitute the subsequent lens group GR with negative optical power. When focusing from an object at infinity to a closer object, the fifth lens group G5, which constitutes the subsequent lens group GR, moves along the optical axis to the object side, and the sixth lens group G6, which constitutes the subsequent lens group GR, moves along the optical axis to the image side. That is, the fifth lens group G5 is equivalent to the first focusing lens group GF1 of the subsequent lens group GR, which is located closest to the object side. The sixth lens group G6 is equivalent to the other focusing lens group, namely the second focusing lens group GF2, which is located on the image side compared to the first focusing lens group GF1.

[0232] Table 2 below shows the values ​​of the parameters of the zoom optical system of the second embodiment.

[0233] (Table 2)

[0234] [Overall Parameters]

[0235]

[0236]

[0237] [Lens Parameters]

[0238]

[0239]

[0240] [Aspherical Data]

[0241] Page 6

[0242] κ=1.0000, A4=1.23369E-06, A6=-3.23247E-09, A8=-1.36560E-12, A10=3.42111E-15

[0243] Page 30

[0244] κ=1.0000, A4=2.14045E-05, A6=-7.56199E-10, A8=-2.61800E-11, A10=1.98882E-13

[0245] Page 31

[0246] κ=1.0000, A4=-3.01641E-06, A6=-1.16781E-08, A8=-5.08849E-11, A10=3.00363E-13

[0247] [Variable Interval Data]

[0248]

[0249] [Lens Group Data]

[0250]

[0251] Figure 5 (A) is a diagram of aberrations when focusing at infinity in the wide-angle end state of the zoom optical system of the second embodiment. Figure 5 (B) is a diagram of aberrations when focusing at infinity in the telephoto end state of the zoom optical system of the second embodiment. Figure 6 (A) is a diagram of aberrations during close-range focusing in the wide-angle end state of the zoom optical system of the second embodiment. Figure 6 (B) is an aberration diagram of the zoom optical system of the second embodiment during close-range focusing in the telephoto end state. As can be seen from the aberration diagram, the zoom optical system of the second embodiment can effectively correct aberrations not only when focusing at infinity but also when focusing at close range, from the wide-angle end state to the telephoto end state, and has excellent imaging performance.

[0252] (Third Embodiment)

[0253] use Figures 7-9 Table 3 illustrates the third embodiment. Figure 7 This is a diagram illustrating the lens structure of the zoom optical system of the third embodiment. The zoom optical system ZL(3) of the third embodiment consists of a first lens group G1 with positive optical power, a second lens group G2 with negative optical power, a third lens group G3 with positive optical power, a fourth lens group G4 with positive optical power, a fifth lens group G5 with positive optical power, a sixth lens group G6 with positive optical power, and a seventh lens group G7 with negative optical power, arranged sequentially along the optical axis from the object side. When zooming from the wide-angle end state (W) to the telephoto end state (T), the first to seventh lens groups G1 to G7 move along the optical axis towards the object side, and the spacing between adjacent lens groups changes. The aperture stop S is positioned between the second lens group G2 and the third lens group G3. During zooming, the aperture stop S moves together with the third lens group G3 along the optical axis.

[0254] The first lens group G1 consists of a concave-plane negative lens L11 with its plane facing the object side and a biconvex positive lens L12 arranged sequentially along the optical axis from the object side, and a positive meniscus lens L13 with its convex surface facing the object side.

[0255] The second lens group G2 consists of a negative meniscus lens L21 with its convex surface facing the object side, a biconcave negative lens L22, and a biconvex positive lens L23 arranged sequentially along the optical axis from the object side, and a plano-concave negative lens L24 with its plane facing the image side. The object-side lens surface of the negative meniscus lens L21 is aspherical.

[0256] The third lens group G3 consists of a positive meniscus lens L31 with its convex surface facing the object side, a biconvex positive lens L32, and a negative meniscus lens L33 with its concave surface facing the object side, arranged sequentially along the optical axis from the object side. The object-side lens surface of the positive meniscus lens L31 is aspherical.

[0257] The fourth lens group G4 consists of a biconvex positive lens L41 arranged sequentially along the optical axis from the object side, a negative meniscus lens L42 with its convex surface facing the object side, and a combined positive lens of the biconvex positive lens L43.

[0258] The fifth lens group G5 consists of a negative meniscus lens L51 with its concave surface facing the object side, arranged sequentially along the optical axis from the object side, and a positive lens L52 with a biconvex shape.

[0259] Lens group G6 consists of a positive meniscus lens L61 with its concave surface facing the object side. The image-side lens surface of the positive meniscus lens L61 is aspherical.

[0260] The seventh lens group G7 consists of a biconcave negative lens L71 and a positive meniscus lens L72 with its convex surface facing the object side, arranged sequentially along the optical axis from the object side. An image plane I is disposed on the image side of the seventh lens group G7.

[0261] In this embodiment, the first lens group G1 constitutes the front lens group GA with positive optical power. The second lens group G2 constitutes the first intermediate lens group GM1 with negative optical power. The third lens group G3 and the fourth lens group G4 together constitute the second intermediate lens group GM2 with positive optical power. The fifth lens group G5, the sixth lens group G6, and the seventh lens group G7 together constitute the subsequent lens group GR with negative optical power. When focusing from an object at infinity to a closer object, the fifth lens group G5 and the sixth lens group G6 constituting the subsequent lens group GR move along the optical axis towards the object side with different trajectories (movement amounts). That is, the fifth lens group G5 is equivalent to the first focusing lens group GF1 of the subsequent lens group GR, which is located closest to the object side. The sixth lens group G6 is equivalent to the other focusing lens group, namely the second focusing lens group GF2, which is located on the image side compared to the first focusing lens group GF1.

[0262] Table 3 below shows the values ​​of the parameters of the zoom optical system of the third embodiment.

[0263] (Table 3)

[0264] [Overall Parameters]

[0265]

[0266]

[0267] [Lens Parameters]

[0268]

[0269]

[0270] [Aspherical Data]

[0271] Page 6

[0272] κ=1.0000, A4=2.28381E-06, A6=-1.46352E-09, A8=-1.25256E-12, A10=5.36019E-15

[0273] Page 14

[0274] κ=1.0000, A4=-2.87497E-06, A6=1.67465E-09, A8=-4.38683E-12, A10=-1.60647E-15

[0275] Page 30

[0276] κ=1.0000, A4=9.04034E-06, A6=8.01114E-10, A8=6.16585E-12, A10=-1.63681E-14

[0277] [Variable Interval Data]

[0278]

[0279] [Lens Group Data]

[0280]

[0281] Figure 8 (A) is a diagram of aberrations when focusing at infinity in the wide-angle end state of the zoom optical system of the third embodiment. Figure 8 (B) is a diagram of aberrations when focusing at infinity in the telephoto end state of the zoom optical system of the third embodiment. Figure 9 (A) is a diagram of aberrations during close-range focusing in the wide-angle end state of the zoom optical system of the third embodiment. Figure 9 (B) is an aberration diagram of the zoom optical system of the third embodiment during close-range focusing in the telephoto end state. As can be seen from the aberration diagram, the zoom optical system of the third embodiment can effectively correct aberrations not only when focusing at infinity but also when focusing at close range, from the wide-angle end state to the telephoto end state, and has excellent imaging performance.

[0282] (Example 4)

[0283] use Figures 10-12 Table 4 illustrates the fourth embodiment. Figure 10 This is a diagram illustrating the lens structure of the zoom optical system of the fourth embodiment. The zoom optical system ZL(4) of the fourth embodiment consists of a first lens group G1 with positive optical power, a second lens group G2 with negative optical power, a third lens group G3 with positive optical power, a fourth lens group G4 with positive optical power, a fifth lens group G5 with negative optical power, a sixth lens group G6 with negative optical power, and a seventh lens group G7 with positive optical power, arranged sequentially along the optical axis from the object side. When zooming from the wide-angle end (W) to the telephoto end (T), the first to sixth lens groups G1 to G6 move along the optical axis towards the object side, and the seventh lens group G7 moves along the optical axis first towards the object side and then towards the image side, with the spacing between adjacent lens groups changing. The aperture stop S is positioned between the second lens group G2 and the third lens group G3. During zooming, the aperture stop S moves together with the third lens group G3 along the optical axis.

[0284] The first lens group G1 consists of a positive lens consisting of a negative meniscus lens L11 with its convex surface facing the object side and a positive meniscus lens L12 with its convex surface facing the object side, arranged sequentially along the optical axis from the object side, and a positive meniscus lens L13 with its convex surface facing the object side.

[0285] The second lens group G2 consists of a positive lens consisting of a negative meniscus lens L21 (convex side facing the object), a negative meniscus lens L22 (convex side facing the object), and a positive meniscus lens L23 (convex side facing the object), arranged sequentially along the optical axis from the object side, and a biconcave negative lens L24. The object-side lens surface of the negative meniscus lens L21 is aspherical.

[0286] The third lens group G3 consists of a positive meniscus lens L31 with its convex surface facing the object and a positive meniscus lens L32 with its convex surface facing the object. The object-side lens surface of the positive meniscus lens L31 is aspherical.

[0287] The fourth lens group G4 consists of a positive lens arranged sequentially along the optical axis from the object side: a negative meniscus lens L41 (convex side facing the object) and a biconvex positive lens L42; a negative lens consisting of a biconvex positive lens L43 and a negative meniscus lens L44 (concave side facing the object); and a positive meniscus lens L45 (concave side facing the object). The object-side lens surface of the positive meniscus lens L45 is aspherical.

[0288] The fifth lens group G5 consists of a biconvex positive lens L51 and a biconcave negative lens L52 arranged sequentially along the optical axis from the object side.

[0289] Lens group G6 consists of a biconcave negative lens L61. The object-side lens surface of the negative lens L61 is aspherical.

[0290] The seventh lens group G7 consists of a positive meniscus lens L71 with its convex surface facing the object side. An image plane I is disposed on the image side of the seventh lens group G7.

[0291] In this embodiment, the first lens group G1 constitutes the front lens group GA with positive optical power. The second lens group G2 constitutes the first intermediate lens group GM1 with negative optical power. The third lens group G3 and the fourth lens group G4 together constitute the second intermediate lens group GM2 with positive optical power. The fifth lens group G5, the sixth lens group G6, and the seventh lens group G7 together constitute the subsequent lens group GR with negative optical power. When focusing from an object at infinity to a closer object, the fifth lens group G5 and the sixth lens group G6 constituting the subsequent lens group GR move along the optical axis to the image side with different trajectories (movement amounts). That is, the fifth lens group G5 is equivalent to the first focusing lens group GF1 of the subsequent lens group GR, which is located closest to the object. The sixth lens group G6 is equivalent to the other focusing lens group, namely the second focusing lens group GF2, which is located on the image side compared to the first focusing lens group GF1.

[0292] Table 4 below shows the values ​​of the parameters of the zoom optical system of the fourth embodiment.

[0293] (Table 4)

[0294] [Overall Parameters]

[0295]

[0296] [Lens Parameters]

[0297]

[0298]

[0299] [Aspherical Data]

[0300] Page 6

[0301] κ=1.0000, A4=3.16658E-06, A6=-5.96049E-09, A8=1.61416E-11, A10=-2.62532E-14

[0302] Page 14

[0303] κ=1.0000, A4=-7.64081E-06, A6=-1.02540E-08, A8=8.93373E-11, A10=-6.51264E-13

[0304] Page 24

[0305] κ=1.0000, A4=-3.12885E-05, A6=3.71787E-08, A8=-1.70544E-10, A10=1.40544E-12

[0306] Page 30

[0307] κ=1.0000, A4=-5.46471E-06, A6=-2.65649E-0, A8=1.47492E-10, A10=-2.98216E-13

[0308] [Variable Interval Data]

[0309]

[0310] [Lens Group Data]

[0311]

[0312] Figure 11 (A) is a diagram of aberrations when focusing at infinity in the wide-angle end state of the zoom optical system of the fourth embodiment. Figure 11 (B) is a diagram of aberrations when focusing at infinity in the telephoto end state of the zoom optical system of the fourth embodiment. Figure 12 (A) is a diagram of aberrations during close-range focusing in the wide-angle end state of the zoom optical system of the fourth embodiment. Figure 12 (B) is an aberration diagram of the zoom optical system of the fourth embodiment during close-range focusing in the telephoto end state. As can be seen from the aberration diagram, the zoom optical system of the fourth embodiment can effectively correct various aberrations not only when focusing at infinity but also when focusing at close range, from the wide-angle end state to the telephoto end state, and has excellent imaging performance.

[0313] (5th embodiment)

[0314] use Figures 13-15 Table 5 illustrates the fifth embodiment. Figure 13 This is a diagram illustrating the lens structure of the zoom optical system of the fifth embodiment. The zoom optical system ZL(5) of the fifth embodiment consists of a first lens group G1 with positive optical power, a second lens group G2 with negative optical power, a third lens group G3 with negative optical power, a fourth lens group G4 with positive optical power, a fifth lens group G5 with positive optical power, a sixth lens group G6 with negative optical power, a seventh lens group G7 with negative optical power, and an eighth lens group G8 with positive optical power, arranged sequentially along the optical axis from the object side. When zooming from the wide-angle end state (W) to the telephoto end state (T), the first to seventh lens groups G1 to G7 move along the optical axis towards the object side, and the eighth lens group G8 moves along the optical axis first towards the object side and then towards the image side, with the spacing between adjacent lens groups changing. The aperture stop S is positioned between the third lens group G3 and the fourth lens group G4. During zooming, the aperture stop S moves along the optical axis together with the fourth lens group G4.

[0315] The first lens group G1 consists of a positive lens consisting of a negative meniscus lens L11 with its convex surface facing the object side and a positive meniscus lens L12 with its convex surface facing the object side, arranged sequentially along the optical axis from the object side, and a positive meniscus lens L13 with its convex surface facing the object side.

[0316] The second lens group G2 consists of a biconcave negative lens L21 arranged sequentially along the optical axis from the object side, a negative meniscus lens L22 with its convex surface facing the object side, and a positive meniscus lens L23 with its convex surface facing the object side, combined with a positive lens. The object-side lens surface of the negative lens L21 is aspherical.

[0317] The third lens group G3 consists of a biconcave negative lens L31.

[0318] The fourth lens group G4 consists of two positive meniscus lenses arranged sequentially along the optical axis, one with its convex surface facing the object side (L41) and the other with its convex surface facing the object side (L42). The object-side lens surface of the positive meniscus lens L41 is aspherical.

[0319] The fifth lens group G5 consists of a positive lens arranged sequentially along the optical axis from the object side: a negative meniscus lens L51 (convex side facing the object) and a biconvex positive lens L52; a negative lens arranged sequentially from the object side to the object side to the object side to the object side to the object side to the object side to the object side to the object side; and a positive meniscus lens L55 (concave side facing the object). The object-side lens surface of the positive meniscus lens L55 is aspherical.

[0320] The sixth lens group G6 consists of a biconvex positive lens L61 and a biconcave negative lens L62 arranged sequentially along the optical axis from the object side.

[0321] Lens group G7 consists of a biconcave negative lens L71. The object-side lens surface of the negative lens L71 is aspherical.

[0322] The eighth lens group G8 consists of a positive meniscus lens L81 with its convex surface facing the object side. An image plane I is disposed on the image side of the eighth lens group G8.

[0323] In this embodiment, the first lens group G1 constitutes the front lens group GA with positive optical power. The second lens group G2 and the third lens group G3 together constitute the first intermediate lens group GM1 with negative optical power. The fourth lens group G4 and the fifth lens group G5 together constitute the second intermediate lens group GM2 with positive optical power. The sixth lens group G6, the seventh lens group G7, and the eighth lens group G8 together constitute the subsequent lens group GR with negative optical power. When focusing from an object at infinity to a closer object, the sixth lens group G6 and the seventh lens group G7, which constitute the subsequent lens group GR, move along the optical axis to the image side with different trajectories (movement amounts). That is, the sixth lens group G6 is equivalent to the first focusing lens group GF1 of the subsequent lens group GR, which is located closest to the object. The seventh lens group G7 is equivalent to the other focusing lens group, namely the second focusing lens group GF2, which is located on the image side compared to the first focusing lens group GF1.

[0324] Table 5 below shows the values ​​of the parameters of the zoom optical system of the fifth embodiment.

[0325] (Table 5)

[0326] [Overall Parameters]

[0327]

[0328] [Lens Parameters]

[0329]

[0330]

[0331]

[0332] [Aspherical Data]

[0333] Page 6

[0334] κ=1.0000, A4=6.01924E-06, A6=-9.78216E-09, A8=1.91188E-11, A10=-2.54581E-14

[0335] Page 14

[0336] κ=1.0000, A4=-8.67328E-06, A6=-1.41146E-08, A8=1.05557E-10, A10=-7.15518E-13

[0337] Page 24

[0338] κ=1.0000, A4=-3.58225E-05, A6=5.16946E-08, A8=-2.69722E-10, A10=2.25425E-12

[0339] Page 30

[0340] κ=1.0000, A4=-5.04731E-06, A6=-3.08030E-08, A8=1.84868E-10, A10=-5.03672E-13

[0341] [Variable Interval Data]

[0342]

[0343] [Lens Group Data]

[0344]

[0345]

[0346] Figure 14 (A) is a diagram of aberrations when focusing at infinity in the wide-angle end state of the zoom optical system of the fifth embodiment. Figure 14 (B) is a diagram of aberrations when focusing at infinity in the telephoto end state of the zoom optical system of the fifth embodiment. Figure 15 (A) is a diagram of aberrations during close-range focusing in the wide-angle end state of the zoom optical system of the fifth embodiment. Figure 15 (B) is an aberration diagram of the zoom optical system of the fifth embodiment during close-range focusing in the telephoto end state. As can be seen from the aberration diagram, the zoom optical system of the fifth embodiment can effectively correct various aberrations not only when focusing at infinity but also when focusing at close range, from the wide-angle end state to the telephoto end state, and has excellent imaging performance.

[0347] (Sixth Embodiment)

[0348] use Figures 16-18 Table 6 describes the sixth embodiment. Figure 16This is a diagram illustrating the lens structure of the zoom optical system of the sixth embodiment. The zoom optical system ZL(6) of the sixth embodiment consists of a first lens group G1 with positive optical power, a second lens group G2 with negative optical power, a third lens group G3 with positive optical power, a fourth lens group G4 with positive optical power, a fifth lens group G5 with negative optical power, a sixth lens group G6 with positive optical power, a seventh lens group G7 with positive optical power, and an eighth lens group G8 with negative optical power, arranged sequentially along the optical axis from the object side. When zooming from the wide-angle end state (W) to the telephoto end state (T), the first to eighth lens groups G1 to G8 move along the optical axis towards the object side, and the spacing between adjacent lens groups changes. The aperture stop S is positioned between the second lens group G2 and the third lens group G3. During zooming, the aperture stop S moves together with the third lens group G3 along the optical axis.

[0349] The first lens group G1 consists of a negative meniscus lens L11 with its convex surface facing the object side, a positive lens L12 with a biconvex shape, and a positive meniscus lens L13 with its convex surface facing the object side, arranged sequentially along the optical axis from the object side.

[0350] The second lens group G2 consists of a negative meniscus lens L21 with its convex surface facing the object side, a biconcave negative lens L22, and a biconvex positive lens L23 arranged sequentially along the optical axis from the object side, and a biconcave negative lens L24. The object-side lens surface of the negative meniscus lens L21 is aspherical.

[0351] The third lens group G3 consists of a positive meniscus lens L31 with its convex surface facing the object side, a biconvex positive lens L32, and a negative meniscus lens L33 with its concave surface facing the object side, arranged sequentially along the optical axis from the object side. The object-side lens surface of the positive meniscus lens L31 is aspherical.

[0352] The fourth lens group G4 consists of a biconvex positive lens L41 arranged sequentially along the optical axis from the object side, a negative meniscus lens L42 with its convex surface facing the object side, and a negative lens that is a combination of the biconvex positive lens L43 and the negative lens.

[0353] The fifth lens group G5 consists of a negative meniscus lens L51 with its concave surface facing the object side.

[0354] The sixth lens group G6 consists of a biconvex positive lens L61.

[0355] Lens group G7 consists of a positive meniscus lens L71 with its concave surface facing the object side. The image-side lens surface of the positive meniscus lens L71 is aspherical.

[0356] The eighth lens group G8 consists of a biconcave negative lens L81 and a positive meniscus lens L82 with its convex surface facing the object side, arranged sequentially along the optical axis from the object side. An image plane I is disposed on the image side of the eighth lens group G8.

[0357] In this embodiment, the first lens group G1 constitutes the front lens group GA with positive optical power. The second lens group G2 constitutes the first intermediate lens group GM1 with negative optical power. The third lens group G3 and the fourth lens group G4 together constitute the second intermediate lens group GM2 with positive optical power. The fifth lens group G5, the sixth lens group G6, the seventh lens group G7, and the eighth lens group G8 together constitute the subsequent lens group GR with negative optical power. When focusing from an object at infinity to a closer object, the fifth lens group G5, the sixth lens group G6, and the seventh lens group G7 constituting the subsequent lens group GR move along the optical axis towards the object side with different trajectories (movement amounts). That is, the fifth lens group G5 is equivalent to the first focusing lens group GF1 of the subsequent lens group GR, which is located closest to the object side. The sixth lens group G6 is equivalent to the other focusing lens group, namely the second focusing lens group GF2, which is located on the image side compared to the first focusing lens group GF1. The 7th lens group G7 is equivalent to the other focusing lens group, namely the 3rd focusing lens group GF3, which is located on the image side compared to the 1st focusing lens group GF1.

[0358] Table 6 below shows the values ​​of the parameters of the zoom optical system of the sixth embodiment.

[0359] (Table 6)

[0360] [Overall Parameters]

[0361]

[0362]

[0363] [Lens Parameters]

[0364]

[0365]

[0366] [Aspherical Data]

[0367] Page 6

[0368] κ=1.0000, A4=1.46132E-06, A6=-1.42920E-09, A8=2.79764E-12, A10=5.33710E-15

[0369] Page 14

[0370] κ=1.0000, A4=-3.76343E-06, A6=1.16052E-09, A8=-1.11309E-11, A10=1.96066E-14

[0371] Page 30

[0372] κ=1.0000, A4=9.30832E-06, A6=3.85397E-09, A8=-9.94633E-12, A10=2.27044E-14

[0373] [Variable Interval Data]

[0374]

[0375]

[0376] [Lens Group Data]

[0377]

[0378] Figure 17 (A) is a diagram of aberrations when focusing at infinity in the wide-angle end state of the zoom optical system of the sixth embodiment. Figure 17 (B) is a diagram of aberrations when focusing at infinity in the telephoto end state of the zoom optical system of the sixth embodiment. Figure 18 (A) is a diagram of aberrations during close-range focusing in the wide-angle end state of the zoom optical system of the sixth embodiment. Figure 18 (B) is an aberration diagram of the zoom optical system of the sixth embodiment during close-range focusing in the telephoto end state. As can be seen from the aberration diagram, the zoom optical system of the sixth embodiment can effectively correct various aberrations not only when focusing at infinity but also when focusing at close range, from the wide-angle end state to the telephoto end state, and has excellent imaging performance.

[0379] (Seventh Embodiment)

[0380] use Figures 19-21 Table 7 describes the seventh embodiment. Figure 19This is a diagram illustrating the lens structure of the zoom optical system of the seventh embodiment. The zoom optical system ZL(7) of the seventh embodiment consists of a first lens group G1 with positive optical power, a second lens group G2 with negative optical power, a third lens group G3 with positive optical power, a fourth lens group G4 with negative optical power, a fifth lens group G5 with positive optical power, a sixth lens group G6 with positive optical power, a seventh lens group G7 with positive optical power, and an eighth lens group G8 with negative optical power, arranged sequentially along the optical axis from the object side. When zooming from the wide-angle end state (W) to the telephoto end state (T), the first to eighth lens groups G1 to G8 move along the optical axis towards the object side, and the spacing between adjacent lens groups changes. The aperture stop S is positioned between the second lens group G2 and the third lens group G3. During zooming, the aperture stop S moves together with the third lens group G3 along the optical axis.

[0381] The first lens group G1 consists of a negative meniscus lens L11 with its convex surface facing the object side, a positive lens L12 with a biconvex shape, and a positive meniscus lens L13 with its convex surface facing the object side, arranged sequentially along the optical axis from the object side.

[0382] The second lens group G2 consists of a negative meniscus lens L21 with its convex surface facing the object side, a biconcave negative lens L22, and a biconvex positive lens L23 arranged sequentially along the optical axis from the object side, and a plano-concave negative lens L24 with its plane facing the image side. The object-side lens surface of the negative meniscus lens L21 is aspherical.

[0383] The third lens group G3 consists of two biconvex positive lenses, L31 and L32, arranged sequentially along the optical axis from the object side. The object-side lens surface of the positive lens L31 is aspherical.

[0384] The fourth lens group G4 consists of a biconcave negative lens L41.

[0385] The fifth lens group G5 consists of a biconvex positive lens L51 arranged sequentially along the optical axis from the object side, a negative meniscus lens L52 with its convex surface facing the object side, and a combined positive lens of the biconvex positive lens L53.

[0386] The sixth lens group G6 consists of a negative meniscus lens L61 with its concave surface facing the object side, arranged sequentially along the optical axis from the object side, and a biconvex positive lens L62.

[0387] Lens group G7 consists of a positive meniscus lens L71 with its concave surface facing the object side. The image-side lens surface of the positive meniscus lens L71 is aspherical.

[0388] The eighth lens group G8 consists of a biconcave negative lens L81 and a positive meniscus lens L82 with its convex surface facing the object side, arranged sequentially along the optical axis from the object side. An image plane I is disposed on the image side of the eighth lens group G8.

[0389] In this embodiment, the first lens group G1 constitutes the front lens group GA with positive optical power. The second lens group G2 constitutes the first intermediate lens group GM1 with negative optical power. The third lens group G3, the fourth lens group G4, and the fifth lens group G5 together constitute the second intermediate lens group GM2 with positive optical power. The sixth lens group G6, the seventh lens group G7, and the eighth lens group G8 together constitute the subsequent lens group GR with negative optical power. When focusing from an object at infinity to a closer object, the sixth lens group G6 and the seventh lens group G7, which constitute the subsequent lens group GR, move along the optical axis towards the object side with different trajectories (movement amounts). That is, the sixth lens group G6 is equivalent to the first focusing lens group GF1 of the subsequent lens group GR, which is located closest to the object side. The seventh lens group G7 is equivalent to the other focusing lens group, namely the second focusing lens group GF2, which is located on the image side compared to the first focusing lens group GF1.

[0390] Table 7 below shows the values ​​of the parameters of the zoom optical system of the seventh embodiment.

[0391] (Table 7)

[0392] [Overall Parameters]

[0393]

[0394]

[0395] [Lens Parameters]

[0396]

[0397]

[0398] [Aspherical Data]

[0399] Page 6

[0400] κ=1.0000, A4=2.33500E-06, A6=-8.92215E-10, A8=-3.76442E-12, A10=9.61354E-15

[0401] Page 14

[0402] κ=1.0000、A4=-2.41342E-06、A6=1.12249E-09A8=-3.73343E-13、A10=-1.07003E-14

[0403] Page 30

[0404] κ=1.0000, A4=9.05002E-06, A6=4.53686E-10, A8=5.24788E-12, A10=-1.61841E-14

[0405] [Variable Interval Data]

[0406]

[0407]

[0408] [Lens Group Data]

[0409]

[0410] Figure 20 (A) is a diagram of aberrations when focusing at infinity in the wide-angle end state of the zoom optical system of the 7th embodiment. Figure 20 (B) is a diagram of aberrations when focusing at infinity in the telephoto end state of the zoom optical system of the 7th embodiment. Figure 21 (A) is a diagram of aberrations during close-range focusing in the wide-angle end state of the zoom optical system of the 7th embodiment. Figure 21 (B) is an aberration diagram of the zoom optical system of the 7th embodiment during close-range focusing in the telephoto end state. As can be seen from the aberration diagram, the zoom optical system of the 7th embodiment can effectively correct various aberrations not only when focusing at infinity but also when focusing at close range, from the wide-angle end state to the telephoto end state, and has excellent imaging performance.

[0411] Next, a table of [corresponding values ​​of conditional expressions] is shown below. In this table, the values ​​corresponding to each conditional expression (1) to (21) are shown together for all embodiments (1 to 7).

[0412] Conditional expression (1)-0.37 <fFs / fFy<0.37

[0413] Conditional expression (2)2.00 <f1 / fw<8.00

[0414] Conditional expression (3)-6.00 <fFs / fw<6.00

[0415] Conditional expression (4)4.30 <f1 / (-fM1w)<10.00

[0416] Conditional expression (5)1.50 <f1 / fM21<7.00

[0417] Conditional expression (6)0.10 <BFw / fw<1.00

[0418] Condition (7) 0.20 < |fFs| / f1 < 2.00

[0419] Condition (8) 1.50 < |fFs| / (-fM1w) < 5.00

[0420] Conditional expression (9) 0.90 < |fFs| / fM2w < 4.00

[0421] Conditional expression (10)0.20 <f1 / (-fRw)<5.00

[0422] Conditional expression (11)0.10 <MTF1 / MTF2<3.00

[0423] Condition (12) 0.10 < βF1w / βF2w < 3.00

[0424] Condition (13) 0.10 < βF1t / βF2t < 3.00

[0425] Conditional expression (14)0.50<βF1w<2.60

[0426] Condition (15) 0.20 < βF2w < 1.80

[0427] Condition (16){βF1w+(1 / βF1w)} -2 ≤0.25

[0428] Condition (17){βF2w+(1 / βF2w)} -2 ≤0.25

[0429] Condition (18) 0.10 < |fFs| / |fRF| < 4.00

[0430] Condition (19) 2ωw>75.0°

[0431] Conditional expression (20)ft / fw>3.50

[0432] Condition (21) 0.10 < (-fN) / fL < 1.00

[0433] [Conditional values] (Examples 1-4)

[0434]

[0435]

[0436] [Conditional values] (Examples 5-7)

[0437]

[0438] According to the above embodiments, by making the focusing lens group small and lightweight, quiet and high-speed focusing can be achieved without making the lens barrel large. In addition, a zoom optical system with minimal aberrations can be achieved when zooming from wide-angle to telephoto and when focusing from infinity to near objects.

[0439] The above embodiments illustrate specific examples of the invention of this application, but the invention of this application is not limited to these.

[0440] The following can be appropriately adopted within the range of not damaging the optical performance of the zoom optical system of this embodiment.

[0441] Although seven-group and eight-group structures are shown as embodiments of the zoom optical system of this embodiment, this application is not limited to these, and other group structures (e.g., nine groups, etc.) can also be constructed for the zoom optical system of this embodiment. Specifically, it is also possible to add a lens or lens group to the side closest to the object or the side closest to the image plane of the zoom optical system of this embodiment. In addition, a lens group refers to a portion having at least one lens that is separated by the air gap that changes during zooming.

[0442] It can also be a focusing lens group that moves one or more lens groups, or part of a lens group, along the optical axis to focus from an object at infinity to a closer object. The focusing lens group is also suitable for autofocus and for motor drives used in autofocus systems (such as those using ultrasonic motors).

[0443] It can also be an image stabilizing lens group that corrects image shake caused by hand tremors by moving the lens group or part of the lens group in a manner that has a component perpendicular to the optical axis, or by rotating (oscillating) in the in-plane direction containing the optical axis.

[0444] The lens surface can be formed from a spherical or flat surface, or from an aspherical surface. When the lens surface is spherical or flat, lens processing and assembly adjustments become easier, preventing degradation of optical performance caused by errors in processing and assembly adjustments, and therefore are preferred. Furthermore, there is less degradation in rendering performance when the image plane is offset, and this is also preferred.

[0445] When the lens surface is aspherical, the aspherical surface can be any of the following: a ground aspherical surface, a glass-molded aspherical surface formed by molding glass into an aspherical shape using a mold, or a composite aspherical surface formed by molding resin into an aspherical shape on the glass surface. Alternatively, the lens surface can also be a diffractive surface, or the lens can be a refractive index distribution lens (GRIN lens) or a plastic lens.

[0446] Although the aperture stop is preferably positioned between the second and third lens groups or between the third and fourth lens groups, it is also possible to omit the aperture stop component and instead use the lens frame to perform its function.

[0447] In order to reduce glare and ghosting and achieve high contrast optical performance, an antireflective coating with high transmittance in a wide wavelength range can also be applied to each lens surface.

[0448] Label Explanation

[0449] G1 Lens Group 1 G2 Lens Group 2

[0450] G3 is the third lens group, and G4 is the fourth lens group.

[0451] G5 is the 5th lens group, and G6 is the 6th lens group.

[0452] G7 7th lens group; G8 8th lens group

[0453] I Image Plane S Aperture Stop

Claims

1. A zoom optical system, wherein, The zoom optical system consists of a front lens group with positive optical power, a first intermediate lens group with negative optical power, a second intermediate lens group with positive optical power, and subsequent lens groups arranged sequentially along the optical axis from the object side. During zooming, the spacing between adjacent lens groups changes. The subsequent lens group includes: a first focusing lens group, which is disposed on the object side of the subsequent lens group and moves along the optical axis during focusing; And at least one other focusing lens group, which is positioned on the image side compared to the first focusing lens group, and moves along the optical axis along a different trajectory than the first focusing lens group during focusing. The zoom optical system satisfies the following condition: -0.37 <fFs / fFy<0.37 2.00 <f1 / fw<8.00 0.20 <f1 / (-fRw)<5.00 Wherein, fFs: the focal length of the focusing lens group with the strongest optical power among the focusing lens groups included in the subsequent lens group. fFy: The focal length of the weakest focusing lens group among the focusing lens groups included in the subsequent lens group. f1: Focal length of the front lens group fw: The focal length of the zoom optical system in the wide-angle state. fRw: The focal length of the subsequent lens group in the wide-angle state.

2. A zoom optical system, wherein, The zoom optical system consists of a front lens group with positive optical power, a first intermediate lens group with negative optical power, a second intermediate lens group with positive optical power, and subsequent lens groups arranged sequentially along the optical axis from the object side. During zooming, the spacing between adjacent lens groups changes. The subsequent lens group includes: a first focusing lens group, which is disposed on the object side of the subsequent lens group and moves along the optical axis during focusing; And at least one other focusing lens group, which is positioned on the image side compared to the first focusing lens group, and moves along the optical axis along a different trajectory than the first focusing lens group during focusing. The zoom optical system satisfies the following condition: -0.37 <fFs / fFy<0.37 2.00 <f1 / fw<8.00 0.90 < |fFs| / fM2w < 4.00 Wherein, fFs: the focal length of the focusing lens group with the strongest optical power among the focusing lens groups included in the subsequent lens group. fFy: The focal length of the weakest focusing lens group among the focusing lens groups included in the subsequent lens group. f1: Focal length of the front lens group fw: The focal length of the zoom optical system in the wide-angle state. fM2w: The focal length of the second intermediate lens group in the wide-angle end state.

3. A zoom optical system, wherein, The zoom optical system consists of a front lens group with positive optical power, a first intermediate lens group with negative optical power, a second intermediate lens group with positive optical power, and subsequent lens groups arranged sequentially along the optical axis from the object side. During zooming, the spacing between adjacent lens groups changes. The subsequent lens group includes: a first focusing lens group, which is disposed on the object side of the subsequent lens group and moves along the optical axis during focusing; And at least one other focusing lens group, which is positioned on the image side compared to the first focusing lens group, and moves along the optical axis along a different trajectory than the first focusing lens group during focusing. The zoom optical system satisfies the following condition: -0.37 <fFs / fFy<0.37 2.00 <f1 / fw<8.00 0.10 < βF1w / βF2w < 1.30 Wherein, fFs: the focal length of the focusing lens group with the strongest optical power among the focusing lens groups included in the subsequent lens group. fFy: The focal length of the weakest focusing lens group among the focusing lens groups included in the subsequent lens group. f1: Focal length of the front lens group fw: The focal length of the zoom optical system in the wide-angle state. βF1w: The composite lateral magnification of the focusing lens group included in the subsequent lens group when focusing on an infinity object at the wide-angle end compared to the focusing lens group located on the object side of the focusing lens group closest to the image side. βF2w: The lateral magnification of the focusing lens group at the wide-angle end of the focusing lens group, which is the closest to the image side, when focusing on an infinity object in the subsequent lens group.

4. A zoom optical system, wherein, The zoom optical system consists of a front lens group with positive optical power, a first intermediate lens group with negative optical power, a second intermediate lens group with positive optical power, and subsequent lens groups arranged sequentially along the optical axis from the object side. The second intermediate lens group has at least two lens groups that can move during zooming. During zooming, the spacing between adjacent lens groups changes. The subsequent lens group includes: a first focusing lens group, which is disposed on the object side of the subsequent lens group and moves along the optical axis during focusing; And at least one other focusing lens group, which is positioned on the image side compared to the first focusing lens group, and moves along the optical axis along a different trajectory than the first focusing lens group during focusing. The zoom optical system satisfies the following condition: -0.35 <fFs / fFy<0.37 2.00 <f1 / fw<8.00 Wherein, fFs: the focal length of the focusing lens group with the strongest optical power among the focusing lens groups included in the subsequent lens group. fFy: The focal length of the weakest focusing lens group among the focusing lens groups included in the subsequent lens group. f1: Focal length of the front lens group fw: The focal length of the zoom optical system in the wide-angle state.

5. The zoom optical system according to any one of claims 1 to 4, wherein, The zoom optical system satisfies the following condition: -6.00 <fFs / fw<6.00。 6. The zoom optical system according to any one of claims 1 to 4, wherein, The zoom optical system satisfies the following condition: 4.30 <f1 / (-fM1w)<10.00 Wherein, fM1w: the focal length of the first intermediate lens group in the wide-angle end state.

7. The zoom optical system according to any one of claims 1 to 4, wherein, The second intermediate lens group comprises at least two lens groups with positive optical power. The zoom optical system satisfies the following condition: 1.50 <f1 / fM21<7.00 Wherein, fM21: the focal length of the lens group closest to the object in the lens group included in the second intermediate lens group.

8. The zoom optical system according to any one of claims 1 to 4, wherein, The zoom optical system satisfies the following condition: 0.10 <BFw / fw<1.00 Wherein, BFw: the back focal length of the zoom optical system in the wide-angle state.

9. The zoom optical system according to any one of claims 1 to 4, wherein, The zoom optical system satisfies the following condition: 0.20 < |fFs| / f1 < 2.

00.

10. The zoom optical system according to any one of claims 1 to 4, wherein, The zoom optical system satisfies the following condition: 1.50 < |fFs| / (-fM1w) < 5.00 Wherein, fM1w: the focal length of the first intermediate lens group in the wide-angle end state.

11. The zoom optical system according to any one of claims 1, 3 to 4, wherein, The zoom optical system satisfies the following condition: 0.90 < |fFs| / fM2w < 4.00 Wherein, fM2w: the focal length of the second intermediate lens group in the wide-angle end state.

12. The zoom optical system according to any one of claims 2 to 4, wherein, The zoom optical system satisfies the following condition: 0.20 <f1 / (-fRw)<5.00 Wherein, fRw: the focal length of the subsequent lens group in the wide-angle state.

13. The zoom optical system according to any one of claims 1 to 4, wherein, The zoom optical system satisfies the following condition: 0.10 <MTF1 / MTF2<3.00 Wherein, MTF1: the absolute value of the amount of movement of the first focusing lens group when focusing from an object at infinity to a closer object in the telephoto state. MTF2: The absolute value of the movement of the closest focusing lens group to the first focusing lens group among the other focusing lens groups when focusing from an object at infinity to a closer object in the telephoto state.

14. The zoom optical system according to any one of claims 1 to 2, 4, wherein, The zoom optical system satisfies the following condition: 0.10 < βF1w / βF2w < 3.00 Wherein, βF1w: the composite lateral magnification of the focusing lens group included in the subsequent lens group when focusing on an infinity object in the wide-angle end state compared to the focusing lens group located on the object side of the focusing lens group closest to the image side. βF2w: The lateral magnification of the focusing lens group at the wide-angle end of the focusing lens group, which is the closest to the image side, when focusing on an infinity object in the subsequent lens group.

15. The zoom optical system according to any one of claims 1 to 4, wherein, The zoom optical system satisfies the following condition: 0.10 < βF1t / βF2t < 3.00 Wherein, βF1t: the composite lateral magnification of the focusing lens group included in the subsequent lens group when focusing on an infinity object at its far focal end compared to the focusing lens group located on the object side of the focusing lens group closest to the image side. βF2t: The lateral magnification when focusing on an infinity object in the far focal length state of the focusing lens group closest to the image side of the subsequent lens group.

16. The zoom optical system according to any one of claims 1 to 4, wherein, The zoom optical system satisfies the following condition: 0.50 < βF1w < 2.60 Wherein, βF1w: the composite lateral magnification of the focusing lens group included in the subsequent lens group when focusing on an infinity object in the wide-angle end state compared to the focusing lens group on the object side of the focusing lens group closest to the image side.

17. The zoom optical system according to any one of claims 1 to 4, wherein, The zoom optical system satisfies the following condition: 0.20 < βF2w < 1.80 Wherein, βF2w: the lateral magnification of the focusing lens group closest to the image side in the focusing lens group included in the subsequent lens group when focusing on an infinity object at the wide-angle end.

18. The zoom optical system according to any one of claims 1 to 4, wherein, The zoom optical system satisfies the following condition: {βF1w+(1 / βF1w)} -2 ≤0.25 Wherein, βF1w: the composite lateral magnification of the focusing lens group included in the subsequent lens group when focusing on an infinity object in the wide-angle end state compared to the focusing lens group on the object side of the focusing lens group closest to the image side.

19. The zoom optical system according to any one of claims 1 to 4, wherein, The zoom optical system satisfies the following condition: {βF2w+(1 / βF2w)} -2 ≤0.25 Wherein, βF2w: the lateral magnification of the focusing lens group closest to the image side in the focusing lens group included in the subsequent lens group when focusing on an infinity object at the wide-angle end.

20. The zoom optical system according to any one of claims 1 to 4, wherein, The subsequent lens group includes at least one lens group disposed on the image side compared to the most image-side focusing lens group among the focusing lens groups included in the subsequent lens group.

21. The zoom optical system according to claim 20, wherein, The zoom optical system satisfies the following condition: 0.10 < |fFs| / |fRF| < 4.00 Wherein, fRF: the focal length of the lens group in the at least one lens group that is arranged adjacent to the image side of the focusing lens group closest to the image side.

22. The zoom optical system according to any one of claims 1 to 4, wherein, The zoom optical system satisfies the following condition: 2ωw>75.0° Wherein, 2ωw: the full field of view of the zoom optical system in the wide-angle state.

23. The zoom optical system according to any one of claims 1 to 4, wherein, The zoom optical system satisfies the following condition: ft / fw>3.50 Wherein, ft: the focal length of the zoom optical system in the telephoto state.

24. The zoom optical system according to any one of claims 1 to 4, wherein, The zoom optical system satisfies the following condition: 0.10 < (-fN) / fL < 1.00 Wherein, fN: the focal length of the lens of the zoom optical system located as the second lens from the image side. fL: The focal length of the lens of the zoom optical system located on the image side.

25. An optical device configured to have the zoom optical system described in any one of claims 1 to 4.

Images