Zoom lens and imaging device

Abstract

To provide a zoom lens advantageous in terms of, for example, a wide angle of view, a high zoom ratio, and high optical performance over the entire zoom range.SOLUTION: A zoom lens (1a) has a first lens group (L1) that does not move for zooming and has a positive refractive power, intermediate groups (L2, L3) that move for zooming and have at least two lens groups, a lens group (L4) that moves for zooming and has a positive refractive power, and a final lens group (L5) that does not move for zooming and has a positive refractive power, which are arranged in order from an object side to an image side. The intermediate groups have one or more lens groups including three lenses and having a negative refractive power. The lens group V (L2) on the most object side of the one or more lens groups having a negative refractive power has at least one positive lens and at least one negative lens, and the lens on the most object side in the lens group V is a negative lens. Predetermined conditional expressions are satisfied.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a zoom lens and an imaging apparatus.

Background Art

[0002] To achieve a high zoom ratio and high optical performance, positive-lead type zoom lenses are known in which a lens unit having positive refractive power is disposed closest to the object side and which include five or more lens units as a whole. Patent Document 1 discloses a zoom lens that is composed of, in order from an object side to an image side, a first lens unit having positive refractive power, a second lens unit having negative refractive power, a third lens unit having negative refractive power, a fourth lens unit having positive refractive power, and a fifth lens unit having positive refractive power, and has a zoom ratio of about 17. Patent Document 2 discloses a zoom lens that is composed of, in order from an object side to an image side, a first lens unit having positive refractive power, a second lens unit having negative refractive power, a third lens unit having negative refractive power, a fourth lens unit having negative refractive power, and a fifth lens unit having positive refractive power, and has a zoom ratio of about 6.5.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of Invention

Problems to be Solved by the Invention

[0004] In a positive-lead type zoom lens, to realize a wide angle of view, a high zoom ratio, and high optical performance, it is necessary to appropriately set the refractive power and the glass material configuration of each lens unit. There is a demand for a zoom lens that is advantageous in terms of a wide angle of view, a high zoom ratio, and high optical performance over the zoom lenses disclosed in Patent Document 1 and Patent Document 2.

[0005] The present invention aims to provide a zoom lens that is advantageous in terms of, for example, a wide angle of view, a high zoom ratio, and high optical performance across the entire zoom range. [Means for solving the problem]

[0006] One aspect of the present invention is a zoom lens comprising a first lens group with positive refractive power that does not move for zooming, arranged sequentially from the object side to the image side, and a second lens group that moves for zooming. ru2 Tsu or three Lens group Consists of An intermediate group, a group of lenses with positive refractive power that move for zooming, and a final group of lenses with positive refractive power that do not move for zooming. Consists of A zoom lens in which, for zooming, the spacing between each set of adjacent lens groups changes, the intermediate group has at least one negative refractive power lens group containing at least three lenses, the lens group V closest to the object among the at least one negative refractive power lens group has at least one positive lens and at least one negative lens, the lens closest to the object in the lens group V is the negative lens, the refractive index of the negative lens closest to the object in the lens group V is n_nf, the partial dispersion ratio and Abbe number of the positive lens closest to the image in the lens group V are θ_pr and v_pr, respectively, the focal length of the first lens group is f1, and the focal length of the lens group V is f2. 1.930 <n_nf<2.200 0.648<θ_pr+0.00253×v_pr<0.678 - 1.88≦ f1 / f2 < -1.00 The following condition is satisfied.

[0007] Other objects and features of the present invention are described in the following examples. [Effects of the Invention]

[0008] According to the present invention, for example, it is possible to provide a zoom lens that is advantageous in terms of wide angle of view, high zoom ratio, and high optical performance across the entire zoom range. [Brief explanation of the drawing]

[0009] [Figure 1] This is a cross-sectional view of the zoom lens in Example 1. [Figure 2] This is an aberration diagram of the zoom lens in Example 1. [Figure 3] This is a cross-sectional view of the zoom lens in Example 2. [Figure 4] This is an aberration diagram of the zoom lens in Example 2. [Figure 5] This is a cross-sectional view of the zoom lens in Example 3. [Figure 6] This is an aberration diagram of the zoom lens in Example 3. [Figure 7] This is a cross-sectional view of the zoom lens in Example 4. [Figure 8] This is an aberration diagram of the zoom lens in Example 4. [Figure 9] This is a cross-sectional view of the zoom lens in Example 5. [Figure 10] This is an aberration diagram of the zoom lens in Example 5. [Figure 11] This is a configuration diagram of an imaging device equipped with a zoom lens in each embodiment. [Modes for carrying out the invention]

[0010] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0011] The zoom lens of each embodiment is suitably used for cinema cameras, broadcast cameras, video cameras, surveillance cameras, digital still cameras, silver halide photography cameras, and the like. The zoom lens of each embodiment includes, arranged in order from an object side to an image side, a first lens unit having a positive refractive power, an intermediate unit, a lens unit having a positive refractive power, and a final lens unit having a positive refractive power. The first lens unit does not move for zooming. The intermediate unit has at least two lens units that move for zooming. The lens unit having a positive refractive power moves for zooming. The final lens unit does not move for zooming. For zooming, the interval between each pair of adjacent lens units changes. The intermediate unit has a lens unit having a negative refractive power that includes at least three lenses. The most object-side lens unit V among the lens units having a negative refractive power includes at least one positive lens and at least one negative lens, and the most object-side lens in the lens unit V is a negative lens.

[0012] Let n_nf be the refractive index of the most object-side negative lens in the lens unit V, θ_pr and v_pr be the partial dispersion ratio and Abbe number of the most image-side positive lens in the lens unit V respectively, f1 be the focal length of the first lens unit, and f2 be the focal length of the lens unit V. At this time, in each embodiment, the following conditional expressions (1) to (3) are satisfied.

[0013] 1.930<n_nf<2.200 ···(1) 0.648<θ_pr+0.00253×v_pr<0.678 ···(2) -3.00<f1 / f2<-1.00 ···(3) Here, the Abbe number v for the d-line is defined as, when the refractive indices for the Fraunhofer d-line (587.6 nm), F-line (486.1 nm), and C-line (656.3 nm) are denoted as Nd, NF, and NC respectively, v=(Nd-1) / (NF-NC) is represented by.

[0014] Furthermore, the partial dispersion ratio θ is given by the refractive indices of the Fraunhofer lines g (435.8 nm), F (486.1 nm), and C (656.3 nm), respectively, where Ng, NF, and NC are the refractive indices. θ = (Ng - NF) / (NF - NC) It is represented as follows.

[0015] Condition (1) specifies the characteristics of the glass material of the negative lens closest to the object in lens group V. By using glass material that satisfies condition (1), a refractive power arrangement advantageous for wide-angle viewing can be achieved, and various aberrations can be suppressed. If the upper limit of condition (1) is exceeded, existing glass materials have particularly low transmittance on the short-wavelength side, so when sensitivity correction is applied in the imaging device, noise is likely to occur in blue subjects. On the other hand, if the lower limit of condition (1) is exceeded, it becomes difficult to achieve wide-angle viewing and suppress various aberrations.

[0016] Condition (2) specifies the characteristics of the glass material of the positive lens closest to the image sensor among the positive lenses included in lens group V. By using glass material that satisfies condition (2), zoom variation of chromatic aberration can be suppressed. If the upper limit of condition (2) is exceeded, it becomes difficult to adequately correct chromatic aberration at the wide-angle end and the zoom variation of chromatic aberration. On the other hand, if the lower limit of condition (2) is exceeded, it becomes difficult to adequately correct axial chromatic aberration at the telephoto end.

[0017] Condition (3) specifies the ratio of the focal lengths of the first lens group and lens group V. Satisfying condition (3) allows for a power arrangement advantageous for wide-angle lenses. Exceeding the upper limit of condition (3) increases the refractive power of the first lens group, making it difficult to suppress aberrations. On the other hand, exceeding the lower limit of condition (3) makes it difficult to achieve wide-angle lenses.

[0018] In each embodiment, preferably, at least one of the following conditional expressions (4) to (9) is satisfied.

[0019] -2.50 <f2 / fw<0.00 ···(4) 0.70 <f21 / f2<2.00 ···(5) 1.70 <n_ave<2.00 ···(6) 60 <v<100 ···(7) -0.0030<(θ_pr-θ_nr) / (v_pr-v_nr)<0.0000 ···(8) -0.0025<(θ_pave-θ_nave) / (v_pave-v_nave)<0.0000 ···(9) Here, fw is the focal length of the zoom lens at the wide-angle end, and f21 is the focal length of the lens closest to the object in lens group V. n_ave is the average refractive index of all lenses included in lens group V. Also, v is the Abbe number of the negative lens included in lens group V. θ_nr and v_nr are the partial dispersion ratio and Abbe number of the negative lens closest to the image, respectively, in lens group V. θ_pave and v_pave are the average partial dispersion ratio and average Abbe number of all positive lenses included in lens group V, respectively. θ_nave and v_nave are the average partial dispersion ratio and average Abbe number of all negative lenses included in lens group V, respectively.

[0020] Condition (4) specifies the ratio of the focal length of lens group V to the focal length of the wide-angle end of the zoom lens. By satisfying condition (4), a high zoom ratio can be achieved while suppressing various aberrations. If the upper limit of condition (4) is exceeded, the refractive power of lens group V weakens, and the lens becomes larger in an attempt to achieve a high zoom ratio. On the other hand, if the lower limit of condition (4) is exceeded, the refractive power of lens group V becomes strong, making it difficult to suppress various aberrations.

[0021] Condition (5) specifies the ratio of the focal length of the lens closest to the object in lens group V to the focal length of lens group V. Satisfying condition (5) enables wide-angle and suppression of various aberrations. Exceeding the upper limit of condition (5) weakens the refractive power of the lens closest to the object, making it difficult to achieve wide-angle. On the other hand, exceeding the lower limit of condition (5) strengthens the refractive power of the lens closest to the object, making it difficult to suppress various aberrations.

[0022] Condition (6) specifies the average refractive index of all lenses included in lens group V. By satisfying condition (6), it is possible to correct various aberrations well while suppressing the increase in lens size. If the upper limit of condition (6) is exceeded, the difference in Abbe numbers between the positive and negative lenses becomes small, and the refractive power of each lens increases, making it difficult to correct various aberrations well. On the other hand, if the lower limit of condition (6) is exceeded, the refractive power of lens group V cannot be increased, and it becomes larger.

[0023] Condition (7) specifies the characteristics of the glass material of the negative lens included in lens group V. By satisfying condition (7), axial chromatic aberration at the telephoto end can be well corrected. Exceeding the upper limit of condition (7) results in a range that does not exist in existing glass materials. On the other hand, exceeding the lower limit of condition (7) makes it difficult to well correct axial chromatic aberration at the telephoto end.

[0024] Condition (8) specifies the achromatic conditions for the two image-side lenses of lens group V. By satisfying condition (8), axial chromatic aberration and lateral chromatic aberration can be well corrected. If the upper limit of condition (8) is exceeded, it becomes difficult to well correct axial chromatic aberration. On the other hand, if the lower limit of condition (8) is exceeded, it becomes difficult to well correct lateral chromatic aberration at the wide-angle end and the zoom variation of lateral chromatic aberration.

[0025] Condition (9) specifies the achromaticity conditions for lens group V. By satisfying condition (9), axial chromatic aberration and lateral chromatic aberration can be well corrected. If the upper limit of condition (9) is exceeded, it becomes difficult to well correct axial chromatic aberration. On the other hand, if the lower limit of condition (9) is exceeded, it becomes difficult to well correct lateral chromatic aberration at the wide-angle end and the zoom variation of lateral chromatic aberration.

[0026] In each embodiment, preferably, the two lenses closest to the image in lens group V are a positive lens and a negative lens. This configuration facilitates correction of zoom variations in chromatic aberration.

[0027] In each embodiment, preferably, lens group V is composed of four lenses. This configuration facilitates the suppression of various aberrations, and in particular, the correction of zoom variations in off-axis aberrations on the wide-angle side.

[0028] In each embodiment, preferably, the first lens group includes a first sub-lens group with negative refractive power, a second sub-lens group with positive refractive power, and a third sub-lens group with positive refractive power, arranged in order from the object side to the image side. For focusing, the spacing between each pair of adjacent sub-lens groups changes. The first sub-lens group does not move for focusing, the second sub-lens group moves for focusing, and the third sub-lens group does not move for focusing. This configuration is effective in achieving wide-angle.

[0029] In each embodiment, more preferably, at least one of the numerical ranges of conditional expressions (1) to (9) is set as follows:

[0030] 1.940 <n_nf<2.150 ···(1a) 0.658<θ_pr+0.00253×v_pr<0.677 (2a) -2.80 <f1 / f2<-1.15 ···(3a) -2.30 <f2 / fw<-0.50 ···(4a) 0.80 <f21 / f2<1.90 ···(5a) 1.73 <n_ave<1.93 ···(6a) 62 <v<97 ···(7a) -0.0029<(θ_pr-θ_nr) / (v_pr-v_nr)<-0.0001 ···(8a) -0.0024<(θ_pave-θ_nave) / (v_pave-v_nave)<-0.0001 ···(9a) In each embodiment, more preferably, at least one of the numerical ranges of conditional expressions (1) to (9) is set as follows:

[0031] 1.950 <n_nf<2.100 ···(1b) 0.668<θ_pr+0.00253×v_pr<0.676 (2b) -2.60 <f1 / f2<-1.30 ···(3b) -2.10 <f2 / fw<-1.30 ···(4b) 0.90 <f21 / f2<1.80 ···(5b) 1.76 <n_ave<1.86 ···(6b) 64 <v<95 ···(7b) -0.0028<(θ_pr-θ_nr) / (v_pr-v_nr)<-0.0002 ···(8b) -0.0023<(θ_pave-θ_nave) / (v_pave-v_nave)<-0.0002 ···(9b) The zoom lenses for each embodiment will be described in detail below. [Examples]

[0032] First, the zoom lens 1a in Embodiment 1 of the present invention will be described with reference to Figures 1 and 2(A) and (B). Figure 1 is a cross-sectional view of the zoom lens 1a at the wide-angle end when focused at infinity. Figure 2(A) is an aberration diagram of the zoom lens 1a at the wide-angle end when focused at infinity, and Figure 2(B) is an aberration diagram of the zoom lens 1a at the telephoto end when focused at infinity. When the zoom lens of each embodiment is used as the imaging optical system of an imaging device, the left side of each cross-sectional view is the subject side (object side), and the right side is the image side.

[0033] The zoom lens 1a consists of a first lens group L1 with positive refractive power, a second lens group L2 with negative refractive power, a third lens group L3 with negative refractive power, a fourth lens group L4 with positive refractive power, an aperture diaphragm SP, and a fifth lens group L5 with positive refractive power, arranged in order from the object side to the image side. The first lens group L1 does not move for zooming. The second and third lens groups L2 and L3 move for zooming and form an intermediate group. The fourth lens group L4 moves for zooming. The fifth lens group L5 is the final lens group for image formation and does not move for zooming.

[0034] The first lens group L1 comprises, in order from the object side to the image side, a first sub-lens group L11 with negative refractive power, a second sub-lens group L12 with positive refractive power, and a third sub-lens group L13 with positive refractive power. The second sub-lens group L12 is a focusing lens group that moves from the object side to the image side when focusing from infinity to a finite distance. The second lens group L2 is a variator lens group with negative refractive power that moves towards the image side when zooming from the wide-angle end to the telephoto end. In this embodiment, the second lens group L2 corresponds to lens group V. An extender lens for focal length conversion may be installed in the fifth lens group L5. In Figure 1, I is the image plane and corresponds to the imaging surface of the image sensor (photoelectric conversion element such as a CCD sensor or CMOS sensor) that receives the optical image formed by the zoom lens 1a. The arrows in Figure 1 show the movement trajectory on the optical axis OA when zooming from the wide-angle end to the telephoto end.

[0035] In each aberration diagram, the solid, dashed, single-dot, and dashed lines in the spherical aberration diagram represent the d, g, C, and F lines, respectively. In the astigmatism diagram, the solid and dashed lines represent the sagittal image plane (ΔS) and meridional image plane (ΔM), respectively, and in the chromatic aberration diagram, the dashed, single-dot, and dashed lines represent the g, C, and F lines, respectively. Astigmatism and chromatic aberration indicate the amount of aberration when the light ray passing through the center of the light beam at the aperture position is considered the principal ray. ω is the half-angle of view (degrees) in the paraxial direction, and Fno is the F number. In the longitudinal aberration diagram, spherical aberration is drawn on a scale of 0.2 mm, astigmatism on a scale of 0.2 mm, distortion on a scale of 5%, and chromatic aberration on a scale of 0.05 mm. In each embodiment, the wide-angle end and telephoto end refer to the zoom positions when the second lens group is located at both ends of the range in which it can move along the optical axis OA due to the mechanism. Furthermore, the explanations regarding the cross-sectional view and aberration diagram of the zoom lens are the same in all subsequent examples unless otherwise specified. [Examples]

[0036] Next, the zoom lens 1b in Embodiment 2 of the present invention will be described with reference to Figures 3 and 4(A) and (B). Figure 3 is a cross-sectional view of the zoom lens 1b at the wide-angle end when focused at infinity. Figure 4(A) is an aberration diagram of the zoom lens 1b at the wide-angle end when focused at infinity, and Figure 4(B) is an aberration diagram of the zoom lens 1b at the telephoto end when focused at infinity.

[0037] The zoom lens 1b consists of a first lens group L1 with positive refractive power, a second lens group L2 with negative refractive power, a third lens group L3 with negative refractive power, a fourth lens group L4 with positive refractive power, an aperture diaphragm SP, and a fifth lens group L5 with positive refractive power, arranged in order from the object side to the image side. The first lens group L1 does not move for zooming. The second and third lens groups L2 and L3 move for zooming and form an intermediate group. The fourth lens group L4 moves for zooming. The fifth lens group L5 is the final lens group for image formation and does not move for zooming.

[0038] The first lens group L1 comprises, in order from the object side to the image side, a first sub-lens group L11 with negative refractive power, a second sub-lens group L12 with positive refractive power, and a third sub-lens group L13 with positive refractive power. The second sub-lens group L12 is a focusing lens group that moves from the object side to the image side when focusing from infinity to a finite distance. The second lens group L2 is a variator lens group with negative refractive power that moves towards the image side when zooming from the wide-angle end to the telephoto end. In this embodiment, the second lens group L2 corresponds to lens group V. The fourth lens group L4 moves together with the aperture diaphragm SP when zooming. The fifth lens group L5 may contain an extender lens for focal length conversion. In Figure 3, I is the image plane and corresponds to the imaging surface of an image sensor (a photoelectric conversion element such as a CCD sensor or CMOS sensor) that receives the optical image formed by the zoom lens 1b. The arrows in Figure 3 indicate the movement trajectory along the optical axis OA during zooming from the wide-angle end to the telephoto end. [Examples]

[0039] Next, the zoom lens 1c in Embodiment 3 of the present invention will be described with reference to Figures 5 and 6(A) and (B). Figure 5 is a cross-sectional view of the zoom lens 1c at the wide-angle end when focused at infinity. Figure 6(A) is an aberration diagram of the zoom lens 1c at the wide-angle end when focused at infinity, and Figure 6(B) is an aberration diagram of the zoom lens 1c at the telephoto end when focused at infinity.

[0040] The zoom lens 1c consists of a first lens group L1 with positive refractive power, a second lens group L2 with negative refractive power, a third lens group L3 with negative refractive power, a fourth lens group L4 with positive refractive power, an aperture diaphragm SP, and a fifth lens group L5 with positive refractive power, arranged in order from the object side to the image side. The first lens group L1 does not move for zooming. The second and third lens groups L2 and L3 move for zooming and form an intermediate group. The fourth lens group L4 moves for zooming. The fifth lens group L5 is the final lens group for image formation and does not move for zooming.

[0041] The first lens group L1 comprises, in order from the object side to the image side, a first sub-lens group L11 with negative refractive power, a second sub-lens group L12 with positive refractive power, and a third sub-lens group L13 with positive refractive power. The second sub-lens group L12 is a focusing lens group that moves from the object side to the image side when focusing from infinity to a finite distance. The second lens group L2 is a variator lens group with negative refractive power that moves towards the image side when zooming from the wide-angle end to the telephoto end. In this embodiment, the second lens group L2 corresponds to lens group V. The aperture diaphragm SP moves during zooming. An extender lens for focal length conversion may be installed in the fifth lens group L5. In Figure 5, I is the image plane and corresponds to the imaging plane of an image sensor (a photoelectric conversion element such as a CCD sensor or CMOS sensor) that receives the optical image formed by the zoom lens 1c. The arrows in Figure 5 indicate the movement trajectory along the optical axis OA during zooming from the wide-angle end to the telephoto end. [Examples]

[0042] Next, the zoom lens 1d in Embodiment 4 of the present invention will be described with reference to Figures 7 and 8(A) and (B). Figure 7 is a cross-sectional view of the zoom lens 1d at the wide-angle end when focused at infinity. Figure 8(A) is an aberration diagram of the zoom lens 1d at the wide-angle end when focused at infinity, and Figure 8(B) is an aberration diagram of the zoom lens 1d at the telephoto end when focused at infinity.

[0043] The zoom lens 1d consists of a first lens group L1, a second lens group L2, a third lens group L3, a fourth lens group, a fifth lens group L5, an aperture diaphragm SP, and a sixth lens group L6, arranged in order from the object side to the image side. The first lens group L1 has positive refractive power and does not move for zooming. The second, third, and fourth lens groups L2, L3, and L4 all have negative refractive power and move for zooming. The second, third, and fourth lens groups L2, L3, and L4 constitute an intermediate group. The fifth lens group L5 has positive refractive power and moves for zooming. The sixth lens group L6 is the final lens group for image formation, has positive refractive power, and does not move for zooming.

[0044] The first lens group L1 comprises, in order from the object side to the image side, a first sub-lens group L11 with negative refractive power, a second sub-lens group L12 with positive refractive power, and a third sub-lens group L13 with positive refractive power. The second sub-lens group L12 is a focusing lens group that moves from the object side to the image side when focusing from infinity to a finite distance. The third lens group L3 is a variator lens group with negative refractive power that moves towards the image side when zooming from the wide-angle end to the telephoto end. In this embodiment, the third lens group L3 corresponds to lens group V. The sixth lens group L6 may contain an extender lens for focal length conversion, etc. In Figure 7, I is the image plane and corresponds to the imaging surface of the image sensor (photoelectric conversion element such as a CCD sensor or CMOS sensor) that receives the optical image formed by the zoom lens 1d. The arrows in Figure 7 show the movement trajectory on the optical axis OA when zooming from the wide-angle end to the telephoto end. [Examples]

[0045] Next, the zoom lens 1e in Embodiment 5 of the present invention will be described with reference to Figures 9 and 10(A) and (B). Figure 9 is a cross-sectional view of the zoom lens 1e at the wide-angle end when focused at infinity. Figure 10(A) is an aberration diagram of the zoom lens 1e at the wide-angle end when focused at infinity, and Figure 10(B) is an aberration diagram of the zoom lens 1e at the telephoto end when focused at infinity.

[0046] The zoom lens 1e consists of a first lens group L1 with positive refractive power, a second lens group L2 with negative refractive power, a third lens group L3 with negative refractive power, a fourth lens group L4 with positive refractive power, an aperture diaphragm SP, and a fifth lens group L5 with positive refractive power, arranged in order from the object side to the image side. The first lens group L1 does not move for zooming. The second and third lens groups L2 and L3 move for zooming and form an intermediate group. The fourth lens group L4 moves for zooming. The fifth lens group L5 is the final lens group for image formation and does not move for zooming.

[0047] The first lens group L1 comprises, in order from the object side to the image side, a first sub-lens group L11 with negative refractive power, a second sub-lens group L12 with positive refractive power, and a third sub-lens group L13 with positive refractive power. The second sub-lens group L12 is a focusing lens group that moves from the object side to the image side when focusing from infinity to a finite distance. The second lens group L2 is a variator lens group with negative refractive power that moves towards the image side when zooming from the wide-angle end to the telephoto end. In this embodiment, the second lens group L2 corresponds to lens group V. An extender lens for focal length conversion may be installed in the fifth lens group L5. In Figure 9, I is the image plane and corresponds to the imaging surface of the image sensor (photoelectric conversion element such as a CCD sensor or CMOS sensor) that receives the optical image formed by the zoom lens 1e. The arrows in Figure 9 show the movement trajectory on the optical axis OA when zooming from the wide-angle end to the telephoto end.

[0048] The following shows numerical examples 1 to 5 corresponding to Examples 1 to 5. In each numerical example, the face number is the order of the faces from the object side, r is the radius of curvature of each face (mm), d is the distance between each face on the optical axis (mm), and nd is the absolute refractive index at 1 atmosphere with respect to the d line of the Fraunhofer lines of the material of the optical component having each face. νd is the Abbe number with respect to the d line of the material of the optical component having each face. θgf is the partial dispersion ratio of the material of the optical component with respect to the g line and the F line. BF is the back focus, which indicates the distance from the final lens surface to the image plane in air equivalent. The total lens length is the distance from the first lens surface to the final lens surface plus the back focus. The aspherical shape is given by the following formula. Here, the X-axis is defined as the direction of the optical axis, the H-axis as the direction perpendicular to the optical axis, and the direction of light propagation is defined as positive. R is the radius of paraxial curvature, k is the cone constant, and A3, A4, A5, A6, A7, A8, A9, A10, A11, A12, A13, A14, A15, and A16 are the aspheric coefficients, respectively.

[0049]

number

[0050] In each aspherical shape, "eX" is "×10 -X This means "[...]". The asterisk (*) to the right of the surface number indicates that the surface is aspherical. In addition to specifications such as focal length and F-number, the half-angle of view of the entire zoom lens system is shown. The data for each lens group indicates the focal length of each lens group. The parts where the spacing d of each optical surface is (variable) change during zooming, and the surface spacing according to the focal length is shown in a separate table.

[0051] <Numerical Example 1> Unit: mm Surface data Face number rd nd νd θgf 1* 4757.030 2.80 1.80100 35.0 0.5864 2 43.063 27.48 3 -75.597 2.20 1.63854 55.4 0.5484 4 239.886 0.15 5 157.499 7.69 1.95906 17.5 0.6598 6 -383.207 1.13 7 200.472 13.03 1.53775 74.7 0.5392 8* -92.576 5.51 9 270.694 10.71 1.48749 70.2 0.5300 10 -95.188 2.10 1.84666 23.8 0.6205 11 -199.911 0.20 12 145.369 2.10 1.80518 25.4 0.6161 13 56.865 13.53 1.43875 94.7 0.5340 14 -1365.080 0.20 15 206.147 6.00 1.43387 95.1 0.5373 16 -334.432 0.20 17 186.419 8.81 1.76385 48.5 0.5589 18 -138.559 (variable) 19* 113.971 1.25 2.00100 29.1 0.5997 20 24.186 6.46 21 -41.222 0.90 1.59522 67.7 0.5442 22 30.642 6.03 1.85478 24.8 0.6122 23 -62.383 3.17 24 -25.353 0.90 1.83481 42.7 0.5648 25 -44.360 (variable) 26 -37.021 0.90 1.60300 65.4 0.5401 27 98.137 2.03 1.85478 24.8 0.6122 28 728.324 (variable) 29* 70.998 6.13 1.90525 35.0 0.5848 30 -103.934 0.20 31 -315.843 1.20 1.95375 32.3 0.5905 32 166.347 3.47 1.61800 63.3 0.5441 33 -137.368 (variable) 34 (aperture) ∞ 1.80 35 168.020 1.80 2.00100 29.1 0.5997 36 49.624 8.61 1.49700 81.5 0.5375 37 -58.231 0.20 38 88.195 6.21 1.51633 64.1 0.5353 39 -53.581 2.00 1.83481 42.7 0.5648 40 243.630 41.99 41 64.451 8.16 1.43875 94.7 0.5340 42 -49.102 4.20 43 255.432 7.95 1.80810 22.8 0.6307 44 -35.562 1.10 2.00100 29.1 0.5997 45 -1466.352 1.00 46 161.235 10.33 1.51742 52.4 0.5564 47 -26.752 1.20 1.89190 37.1 0.5780 48 51.269 0.72 49 37.558 10.15 1.48749 70.2 0.5300 50 -58.875 42.54 Image plane ∞ Aspherical data Front page K =-2.00000e+00 A 4= 9.46087e-07 A 6= 1.98046e-09 A 8= 6.52397e-12 A10= 8.28901e-15 A12=-1.35643e-19 A14=-1.86398e-21 A16=-5.54763e-26 A 3=-1.81264e-06 A 5=-2.33898e-08 A 7=-1.25328e-10 A 9=-2.69889e-13 A11=-1.52146e-16 A13= 8.26328e-20 A15= 1.72135e-23 Surface 8 K =-1.02997e+00 A 4= 5.48630e-07 A 6= 2.34979e-10 A 8=-1.89359e-15 A10=-6.91188e-16 A12=-7.25113e-20 A 3=-3.10939e-07 A 5=-1.89555e-09 A 7=-1.00407e-11 A 9= 1.71125e-14 A11= 1.12862e-17 Surface 19 K =-2.00013e+00 A 4= 4.92053e-06 A 6=-5.35701e-08 A 8=-2.79944e-09 A10=-1.33097e-11 A12=-3.74615e-15 A 3=-1.29064e-06 A 5=-9.34903e-08 A 7= 1.78894e-08 A 9= 2.53904e-10 A11= 3.63938e-13 Surface 29 K = 8.99851e-01 A 4=-2.76907e-06 A 6=-1.06240e-07 A 8=-2.88426e-09 A10=-1.28512e-11 A12= 1.83249e-15 A14= 1.77924e-17 A16= 3.66574e-21 A 3=-3.97104e-07 A 5= 2.76818e-07 A 7= 2.21858e-08 A 9= 2.43469e-10 A11= 3.46270e-13 A13=-4.90518e-16 A15=-3.48843e-19 Various data Zoom ratio 7.79 Wide-angle, Medium, Telephoto Focal length 15.40 45.00 120.00 F-numbers: 2.72, 2.71, 3.65 Half-angle 43.86 18.21 7.03 Image height 14.80 14.80 14.80 Lens length 347.55 347.55 347.55 BF 42.54 42.54 42.54 d18 1.15 37.22 55.04 d25 39.95 4.59 3.36 d28 10.52 14.59 0.79 d33 9.50 4.72 1.92 Zoom lens group data Group starting plane focal length 1 1 46.81 2 19 -24.89 3 26 -67.11 4 29 49.01 5 34 96.11 <Numerical Example 2> Unit: mm Surface data Face number rd nd νd θgf 1* -80975.653 2.80 1.79360 37.1 0.5828 2 43.117 29.77 3 -82.938 2.20 1.64000 60.1 0.5370 4 214.176 0.15 5 153.896 9.02 1.92286 18.9 0.6495 6 -343.598 1.13 7 198.846 14.41 1.49700 81.5 0.5375 8* -92.193 8.92 9 397.557 8.89 1.48749 70.2 0.5300 10 -141.693 2.10 1.84666 23.8 0.6205 11 -182.949 0.20 12 346.662 2.10 1.84666 23.8 0.6205 13 59.135 17.03 1.49700 81.5 0.5375 14 -372.774 1.55 15 241.479 9.49 1.43875 94.7 0.5340 16 -194.701 2.00 17 136.007 12.05 1.76385 48.5 0.5589 18 -157.804 (variable) 19* 111.551 1.25 1.95375 32.3 0.5898 20 24.749 7.06 21 -37.681 0.90 1.55200 70.7 0.5421 22 33.995 7.47 1.85478 24.8 0.6122 23 -64.164 4.84 24 -26.795 0.90 1.83481 42.7 0.5648 25 -55.693 (variable) 26 -37.114 0.90 1.60300 65.4 0.5401 27 121.589 1.97 1.85478 24.8 0.6122 28 -4752.316 (variable) 29* 56.750 8.97 1.90525 35.0 0.5848 30 -125.262 0.20 31 1018.417 1.20 1.95375 32.3 0.5905 32 74.495 5.35 1.61800 63.3 0.5441 33 -921.244 3.00 34 (aperture) ∞ (variable) 35 104.379 1.80 2.00100 29.1 0.5997 36 42.340 8.17 1.49700 81.5 0.5375 37 -70.551 3.43 38 127.421 5.85 1.51633 64.1 0.5353 39 -48.058 1.10 1.83481 42.7 0.5648 40 367.685 37.96 41 59.181 8.13 1.43875 94.7 0.5340 42 -46.735 4.20 43 203.248 8.95 1.80810 22.8 0.6307 44 -30.077 1.10 2.00100 29.1 0.5997 45 28572.268 0.88 46 340.443 7.42 1.51742 52.4 0.5564 47 -24.606 1.20 1.89190 37.1 0.5780 48 58.804 0.19 49 36.642 10.96 1.48749 70.2 0.5300 50 -58.875 39.46 Image plane ∞ Aspherical data Front page K = 2.81796e+06 A 4= 1.03360e-06 A 6= 2.22616e-09 A 8= 6.64699e-12 A10= 8.25635e-15 A12=-1.29115e-19 A14=-1.86052e-21 A16=-5.67531e-26 A 3=-2.01854e-06 A 5=-2.91974e-08 A 7=-1.31926e-10 A 9=-2.69845e-13 A11=-1.52534e-16 A13= 8.27334e-20 A15= 1.72123e-23 8th surface K = 1.55912e-01 A 4= 8.28256e-07 A 6= 1.46760e-10 A 8=-4.25985e-13 A10=-1.28537e-15 A12=-1.27993e-19 A 3=-2.72967e-07 A 5=-7.75448e-10 A 7=-4.77605e-12 A 9= 3.85675e-14 A11= 2.00524e-17 19th surface K =-1.60377e+01 A 4= 5.61108e-06 A 6=-3.90328e-08 A 8=-2.44561e-09 A10=-1.47919e-11 A12=-5.11712e-15 A 3=-4.38412e-07 A 5=-3.20826e-08 A 7= 1.34667e-08 A 9= 2.54149e-10 A11= 4.41870e-13 29th surface K =-4.43728e-01 A 4=-2.05558e-06 A 6=-1.13787e-07 A 8=-2.93241e-09 A10=-1.28418e-11 A12= 1.90141e-15 A14= 1.73953e-17 A16= 2.34539e-21 A 3=-8.66761e-07 A 5= 2.62283e-07 A 7= 2.33620e-08 A 9= 2.42673e-10 A11= 3.52284e-13 A13=-5.08578e-16 A15=-2.87640e-19 Various data Zoom ratio 7.41 Wide-angle, Medium, Telephoto Focal length 15.89 44.17 117.70 F-number 2.72 2.72 3.65 Half-angle 42.97 18.52 7.17 Image height 14.80 14.80 14.80 Lens length 360.95 360.95 360.95 BF 39.46 39.46 39.46 d18 1.15 30.49 44.98 d25 30.48 1.53 2.55 d28 16.70 18.81 0.80 d34 4.00 1.50 4.00 Zoom lens group data Group starting plane focal length 1 1 39.27 2 19 -24.20 3 26 -71.56 4 29 50.05 5 35 105.61 <Numerical Example 3> Unit: mm Surface data Face number rd nd νd θgf 1* 682.597 2.80 1.80100 35.0 0.5864 2 44.019 28.11 3 -75.579 2.20 1.63854 55.4 0.5484 4 271.041 0.15 5 164.204 7.32 1.95906 17.5 0.6598 6 -419.663 1.13 7 196.967 13.71 1.53775 74.7 0.5392 8* -91.986 5.98 9 390.132 10.37 1.48749 70.2 0.5300 10 -87.834 2.10 1.84666 23.8 0.6205 11 -166.917 0.20 12 130.921 2.10 1.80518 25.4 0.6161 13 56.379 11.13 1.43875 94.7 0.5340 14 287.620 0.41 15 166.994 7.34 1.43387 95.1 0.5373 16 -242.971 0.20 17 217.677 8.47 1.76385 48.5 0.5589 18 -136.489 (variable) 19* 67.023 1.25 1.95375 32.3 0.5905 20 23.164 7.54 21 -31.887 0.90 1.53775 74.7 0.5392 22 35.834 7.61 1.85478 24.8 0.6122 23 -59.879 3.46 24 -25.848 0.90 1.85150 40.8 0.5695 25 -63.017 (variable) 26 -41.947 0.90 1.60300 65.4 0.5401 27 201.255 1.75 1.85478 24.8 0.6122 28 -723.779 (variable) 29* 74.615 5.31 1.90525 35.0 0.5848 30 -130.844 0.20 31 -938.922 1.20 1.95375 32.3 0.5905 32 124.736 4.90 1.61800 63.3 0.5441 33 -94.103 (variable) 34 (aperture) ∞ (variable) 35 184.408 1.57 2.00100 29.1 0.5997 36 54.629 7.64 1.49700 81.5 0.5375 37 -70.903 0.38 38 139.687 6.12 1.51633 64.1 0.5353 39 -54.704 1.81 1.83481 42.7 0.5648 40 842.741 49.20 41 65.355 9.09 1.43875 94.7 0.5340 42 -50.154 3.87 43 121.895 9.17 1.80810 22.8 0.6307 44 -32.947 1.10 2.00100 29.1 0.5997 45 141.812 1.00 46 113.862 10.30 1.51742 52.4 0.5564 47 -25.202 1.20 1.89190 37.1 0.5780 48 53.312 0.93 49 38.396 11.60 1.48749 70.2 0.5300 50 -50.176 39.33 Image plane ∞ Aspherical data Front page K =-1.03286e+03 A 4= 1.01446e-06 A 6= 1.99948e-09 A 8= 6.47002e-12 A10= 8.26746e-15 A12=-1.30938e-19 A14=-1.86815e-21 A16=-5.37265e-26 A 3=-9.63982e-07 A 5=-3.11557e-08 A 7=-1.23164e-10 A 9=-2.66847e-13 A11=-1.53173e-16 A13= 8.29800e-20 A15= 1.71301e-23 8th surface K =-5.00024e-01 A 4= 5.88521e-07 A 6= 4.04912e-10 A 8= 2.33313e-13 A10=-8.70831e-16 A12=-1.05191e-19 A 3=-4.72093e-08 A 5=-3.87237e-09 A 7=-1.92315e-11 A 9= 1.77457e-14 A11= 1.54121e-17 19th surface K =-3.57906e-01 A 4= 5.54135e-06 A 6=-5.36395e-08 A 8=-2.66631e-09 A10=-1.33626e-11 A12=-3.27118e-15 A 3=-1.97411e-06 A 5=-1.00050e-07 A 7= 1.72704e-08 A 9= 2.48154e-10 A11= 3.61534e-13 29th surface K = 1.71424e+00 A 4=-2.82397e-06 A 6=-1.00565e-07 A 8=-2.83914e-09 A10=-1.28763e-11 A12= 1.82130e-15 A14= 1.78348e-17 A16= 3.44697e-21 A 3= 1.32513e-08 A 5= 2.55488e-07 A 7= 2.14769e-08 A 9= 2.42368e-10 A11= 3.47724e-13 A13=-4.90439e-16 A15=-3.46418e-19 Various data Zoom ratio 8.52 Wide-angle, Medium, Telephoto Focal length 16.57 49.64 141.12 F-number 3.11 2.79 4.11 Half-angle 41.77 16.60 5.99 Image height 14.80 14.80 14.80 Lens length 357.99 357.99 357.99 BF 39.33 39.33 39.33 d18 1.15 38.63 57.15 d25 51.22 8.64 4.38 d28 6.50 14.64 0.80 d33 3.15 0.50 0.50 d34 2.00 1.60 1.19 Zoom lens group data Group starting plane focal length 1 1 50.41 2 19 -22.93 3 26 -83.97 4 29 47.12 5 34 ∞ 6 35 120.21 <Numerical Example 4> Unit: mm Surface data Face number rd nd νd θgf 1* 11251.524 2.80 1.80100 35.0 0.5864 2 42.409 27.61 3 -74.779 2.20 1.63854 55.4 0.5484 4 247.388 0.15 5 160.219 7.76 1.95906 17.5 0.6598 6 -348.406 2.30 7 192.665 12.67 1.53775 74.7 0.5392 8* -95.060 8.73 9 258.088 10.24 1.48749 70.2 0.5300 10 -98.861 2.10 1.84666 23.8 0.6205 11 -199.624 0.20 12 142.312 2.10 1.80518 25.4 0.6161 13 56.983 13.30 1.43875 94.7 0.5340 14 -1153.744 0.26 15 223.620 6.00 1.43387 95.1 0.5373 16 -301.040 0.20 17 186.491 8.39 1.76385 48.5 0.5589 18 -142.986 (variable) 19 238.037 0.66 1.43875 94.7 0.5340 20 126.721 (variable) 21* 103.714 1.25 2.00100 29.1 0.5997 22 24.986 6.77 23 -39.159 0.90 1.59522 67.7 0.5442 24 32.344 7.02 1.85025 30.1 0.5979 25 -43.506 1.49 26 -27.264 0.90 1.80400 46.5 0.5577 27 -53.319 (variable) 28 -33.895 0.90 1.60300 65.4 0.5401 29 61.138 2.31 1.85478 24.8 0.6122 30 185.293 (variable) 31* 70.752 5.82 1.90525 35.0 0.5848 32 -112.235 0.20 33 -302.519 1.20 1.95375 32.3 0.5905 34 267.587 2.18 1.61800 63.3 0.5441 35 -337.030 (variable) 36 (aperture) ∞ 1.80 37 156.439 1.10 2.00100 29.1 0.5997 38 50.688 7.99 1.49700 81.5 0.5375 39 -54.001 0.20 40 74.805 8.31 1.51633 64.1 0.5353 41 -50.184 1.89 1.83481 42.7 0.5648 42 344.709 37.38 43 63.319 8.06 1.43875 94.7 0.5340 44 -47.262 2.47 45 272.878 8.36 1.80810 22.8 0.6307 46 -34.074 1.10 2.00100 29.1 0.5997 47 -972.762 0.98 48 195.543 9.83 1.51742 52.4 0.5564 49 -26.917 1.20 1.89190 37.1 0.5780 50 50.707 1.35 51 37.878 11.09 1.48749 70.2 0.5300 52 -58.875 42.26 Image plane ∞ Aspherical data Front page K = 5.54776e+04 A 4= 1.02030e-06 A 6= 1.94479e-09 A 8= 6.51265e-12 A10= 8.28949e-15 A12=-1.35468e-19 A14=-1.86411e-21 A16=-5.54594e-26 A 3=-1.71759e-06 A 5=-2.35174e-08 A 7=-1.24279e-10 A 9=-2.69994e-13 A11=-1.52068e-16 A13= 8.26178e-20 A15= 1.72130e-23 Surface 8 K =-1.09620e+00 A 4= 5.68866e-07 A 6= 2.25662e-10 A 8= 8.92790e-15 A10=-7.01507e-16 A12=-7.54486e-20 A 3=-3.20833e-07 A 5=-1.74657e-09 A 7=-1.00123e-11 A 9= 1.70258e-14 A11= 1.15929e-17 Surface 21 K =-4.28440e+00 A 4= 4.94392e-06 A 6=-5.74230e-08 A 8=-2.83872e-09 A10=-1.33801e-11 A12=-3.77089e-15 A 3=-7.48057e-07 A 5=-6.83566e-08 A 7= 1.84340e-08 A 9= 2.55765e-10 A11= 3.66150e-13 Surface 31 K = 1.68740e+00 A 4=-2.62447e-06 A 6=-1.07776e-07 A 8=-2.88389e-09 A10=-1.28078e-11 A12= 1.80598e-15 A14= 1.78772e-17 A16= 3.56583e-21 A 3=-7.46477e-07 A 5= 2.77185e-07 A 7= 2.23204e-08 A 9= 2.42673e-10 A11= 3.45886e-13 A13=-4.91556e-16 A15=-3.47238e-19 Various data Zoom ratio 7.31 Wide-angle, Medium, Telephoto Focal length 15.85 45.00 115.88 F-number 2.71 2.71 3.65 Half-angle 43.03 18.21 7.28 Image height 14.80 14.80 14.80 Lens length 346.18 346.18 346.18 BF 42.26 42.26 42.26 d18 0.20 8.53 13.42 d20 0.29 30.28 44.33 d27 33.60 1.20 2.85 d30 14.09 14.78 0.80 d35 14.02 7.41 0.80 Zoom lens group data Group starting plane focal length 1 1 44.40 2 19 -618.73 3 21 -31.71 4 28 -54.44 5 31 55.44 6 36 83.91 <Numerical Example 5> Unit: mm Surface data Face number rd nd νd θgf 1* 293.374 2.80 1.80100 35.0 0.5864 2 43.844 19.49 3 722.817 2.20 1.80100 35.0 0.5864 4 186.698 12.23 5 -85.899 2.20 1.63854 55.4 0.5484 6 614.885 0.15 7 198.065 7.53 1.95906 17.5 0.6598 8 -366.904 2.53 9 160.257 16.32 1.52841 76.5 0.5396 10* -104.808 10.02 11 193.188 11.88 1.49700 81.5 0.5375 12 -163.662 2.10 1.80810 22.8 0.6307 13 -278.157 0.20 14 177.253 2.10 1.80518 25.4 0.6161 15 57.914 16.89 1.43875 94.7 0.5340 16 -311.191 0.66 17 208.858 6.00 1.43387 95.1 0.5373 18 -526.675 0.48 19 185.542 5.18 1.43387 95.1 0.5373 20 -919.505 0.64 21 119.886 8.67 1.76385 48.5 0.5589 22 -297.546 (variable) 23* 155.145 1.25 2.00330 28.3 0.5980 24 22.448 7.04 25 -65.034 0.90 1.52841 76.5 0.5396 26 26.504 9.62 1.78880 28.4 0.6009 27 -40.069 1.47 28 -29.752 0.90 1.77250 49.6 0.5520 29 -178.790 (variable) 30 -25.906 0.90 1.60300 65.4 0.5401 31 53.733 2.53 1.85478 24.8 0.6122 32 1560.803 (variable) 33* 51.701 6.74 1.90525 35.0 0.5848 34 -173.045 0.20 35 208.217 1.20 1.95375 32.3 0.5905 36 35.260 6.83 1.61800 63.3 0.5441 37 336.533 (variable) 38 (aperture) ∞ 1.80 39 82.389 1.80 1.95375 32.3 0.5905 40 56.298 7.35 1.49700 81.5 0.5375 41 -105.447 7.77 42 98.328 7.54 1.51633 64.1 0.5353 43 -42.277 2.00 1.85150 40.8 0.5695 44 123.007 20.94 45 60.046 8.83 1.43875 94.7 0.5340 46 -42.904 4.20 47 100.749 9.16 1.80810 22.8 0.6307 48 -27.659 1.10 2.00100 29.1 0.5997 49 118.913 1.00 50 81.793 9.51 1.51742 52.4 0.5564 51 -27.532 1.20 1.90525 35.0 0.5848 52 61.505 0.28 53 39.628 9.55 1.51633 64.1 0.5353 54 -58.875 44.14 Image plane ∞ Aspherical data Front page K =-3.44971e+01 A 4= 8.53550e-07 A 6= 3.82655e-09 A 8= 6.63229e-12 A10= 8.24360e-15 A12=-5.16527e-19 A14=-1.85266e-21 A16=-5.25439e-26 A 3=-6.21894e-07 A 5=-4.74839e-08 A 7=-1.80525e-10 A 9=-2.49357e-13 A11=-1.51402e-16 A13= 8.96210e-20 A15= 1.63703e-23 Side 10 K =-2.95095e+00 A 4= 4.27700e-07 A 6= 1.45247e-10 A 8= 2.25802e-13 A10=-6.22602e-16 A12=-8.41239e-20 A 3= 2.67717e-07 A 5=-1.10611e-09 A 7=-9.81919e-12 A 9= 8.96999e-15 A11 = 1.22692e-17 Page 23 K =-8.64316e+01 A 4= 6.46097e-06 A 6=-8.40957e-08 A 8=-3.02313e-09 A10=-1.27004e-11 A12=-4.75910e-15 A 3= 5.32901e-06 A 5= 1.32916e-07 A 7= 2.12859e-08 A 9= 2.51982e-10 A11 = 3.68446e-13 Page 33 K =-1.28543e-02 A 4=-2.42156e-06 A 6=-1.11378e-07 A 8=-2.84388e-09 A10=-1.29849e-11 A12= 6.47086e-17 A14= 1.78237e-17 A16= 5.62346e-21 A 3=-2.59081e-07 A 5= 3.24367e-07 A 7= 2.22569e-08 A 9= 2.40461e-10 A11= 3.74538e-13 A13=-4.31951e-16 A15=-4.31461e-19 Various data Zoom ratio 7.63 Wide-angle, Medium, Telephoto Focal length 17.66 44.74 134.64 F-number 3.00 3.00 4.00 Half-angle 39.97 18.30 6.27 Image height 14.80 14.80 14.80 Lens length 368.55 368.55 368.55 BF 44.14 44.14 44.14 d22 1.50 24.26 35.51 d29 13.22 3.96 7.16 d32 29.61 24.52 0.80 d37 16.19 7.78 17.05 Zoom lens group data Group starting plane focal length 1 1 34.52 2 23 -25.89 3 30 -52.36 4 33 60.92 5 38 93.71 Table 1 shows the values ​​of each conditional expression in numerical examples 1 to 5.

[0052] [Table 1]

[0053] (Imaging device) Next, with reference to Figure 11, the imaging device 125 equipped with the zoom lens of each embodiment will be described. Figure 11 is a configuration diagram of the imaging device 125. In Figure 11, 101 is a zoom lens of any of Embodiments 1 to 5. 124 is the camera body (imaging device body). The zoom lens 101 is detachable from the camera body 124. 125 is an imaging device configured by attaching the zoom lens 101 to the camera body 124. The zoom lens 101 has a first lens group F (corresponding to the first lens group L1), a zoom section LZ, and a rear lens group R for image formation (lens groups R1, R2: corresponding to the final lens group). The first lens group F includes a lens group that moves during focusing.

[0054] The zoom section LZ includes at least two lens groups that move during zooming. The aperture diaphragm SP, lens group R1, and lens group R2 are located on the image side of the zoom section LZ. The imaging device 125 also has a lens unit IE that can be inserted into and removed from the optical path between lens group R1 and lens group R2. By inserting the lens unit IE between lens group R1 and lens group R2, the range of the focal length of the entire zoom lens system 101 can be altered.

[0055] 114 and 115 are drive mechanisms that drive the first lens group F and the zoom section LZ in the optical axis direction, respectively. The drive mechanisms may include a helicoid, a cam, etc. 116 to 118 are motors (drive units) for driving the drive mechanisms 114 and 115 and the aperture diaphragm SP, respectively. 119 to 121 are detection units for detecting the position of the first lens group F on the optical axis, the position of the zoom section LZ on the optical axis, and the aperture diameter of the aperture diaphragm SP, respectively. The detection units may include an encoder, a potentiometer, a photosensor, etc.

[0056] In the camera body 124, 109 is a glass block including an optical filter, etc., and 110 is an image sensor (photoelectric conversion element) that captures the subject image formed by the zoom lens 101. The image sensor 110 may be composed of a CCD sensor or a CMOS sensor, etc. 111 and 122 are the CPU as the processing unit (control unit) in the camera body 124 and the CPU as the processing unit (control unit) in the zoom lens 101, respectively.

[0057] According to each embodiment, for example, it is possible to provide a zoom lens and imaging device that are advantageous in terms of wide angle of view, high zoom ratio, and high optical performance across the entire zoom range.

[0058] Each embodiment disclosed includes the following configuration:

[0059] (Composition 1) A zoom lens comprising: a first lens group with positive refractive power that does not move for zooming and is arranged sequentially from the object side to the image side; an intermediate group having at least two lens groups that move for zooming; a lens group with positive refractive power that moves for zooming; and a final lens group with positive refractive power that does not move for zooming, For zooming, the spacing between each set of adjacent lens groups changes. The intermediate group has at least one negative refractive power lens group including at least three lenses, The lens group V closest to the object among the aforementioned group of at least one negative refractive power lenses has at least one positive lens and at least one negative lens, and the lens closest to the object in lens group V is the negative lens. Let n_nf be the refractive index of the negative lens closest to the object in the lens group V, θ_pr and v_pr be the partial dispersion ratio and Abbe number of the positive lens closest to the image in the lens group V, respectively, let f1 be the focal length of the first lens group, and f2 be the focal length of the lens group V. 1.930 <n_nf<2.200 0.648<θ_pr+0.00253×v_pr<0.678 -3.00 <f1 / f2<-1.00 A zoom lens characterized by satisfying the following conditional equation. (Configuration 2) Let fw be the focal length of the zoom lens at the wide-angle end. -2.50 <f2 / fw<0.00 A zoom lens according to configuration 1, characterized in that it satisfies the following condition. (Composition 3) Let the focal length of the lens closest to the object in the aforementioned lens group V be f21. 0.70 <f21 / f2<2.00 A zoom lens according to configuration 1 or 2, characterized by satisfying the following conditional expression. (Composition 4) Let n_ave be the average refractive index of all lenses included in the aforementioned lens group V. 1.70 <n_ave<2.00 A zoom lens according to any one of configurations 1 to 3, characterized by satisfying the following conditional expression. (Composition 5) Let v be the Abbe number. The lens group V is: 60 <v<100 A zoom lens according to any one of configurations 1 to 4, characterized by having a negative lens that satisfies the following condition. (Composition 6) Let v_pave and θ_pave be the average Abbe number and average partial variance ratio of all positive lenses included in the lens group V, respectively, and let v_nave and θ_nave be the average Abbe number and average partial variance ratio of all negative lenses included in the lens group V, respectively. -0.0030<(θ_pave-θ_nave) / (v_pave-v_nave)<0.0000 A zoom lens according to any one of configurations 1 to 5, characterized in that it satisfies the following conditional expression. (Composition 7) A zoom lens according to any one of configurations 1 to 6, characterized in that the lens closest to the image and the second lens from the image in the lens group V are a positive lens and a negative lens, respectively. (Composition 8) Let v_nr and θ_nr be the Abbe number and partial dispersion ratio of the image-side lens among the negative lenses included in the lens group V, respectively. -0.0025<(θ_pr-θ_nr) / (v_pr-v_nr)<0.0000 A zoom lens according to any one of configurations 1 to 7, characterized by satisfying the following conditional expression. (Composition 9) The zoom lens according to any one of configurations 1 to 8, characterized in that the lens group V consists of four lenses. (Composition 10) The first lens group comprises a first sub-lens group with negative refractive power, a second sub-lens group with positive refractive power, and a third sub-lens group with positive refractive power, arranged in order from the object side to the image side. For focusing, the spacing between each set of adjacent sub-lens groups changes. A zoom lens according to any one of configurations 1 to 9, characterized in that the first sub-lens group does not move for focusing, the second sub-lens group moves for focusing, and the third sub-lens group does not move for focusing. (Composition 11) The aforementioned intermediate group consists of a second lens group, a third lens group, and a fourth lens group, arranged in order from the object side to the image side. The zoom lens according to any one of configurations 1 to 10, characterized in that the lens group V is the second lens group. (Composition 12) The aforementioned intermediate group consists of a second lens group, a third lens group, a fourth lens group, and a fifth lens group, arranged in order from the object side to the image side. The zoom lens according to any one of configurations 1 to 10, characterized in that the lens group V is the third lens group. (Composition 13) A zoom lens as described in any one of configurations 1 to 12, An imaging device characterized by having an image sensor that captures an image formed by the zoom lens.

[0060] Although preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of its essence. [Explanation of Symbols]

[0061] 1a~1e Zoom Lens L1 First lens group L2 Second lens group (intermediate group) L3 Third lens group (intermediate group) L4 4th lens group (intermediate group) L5 Fifth lens group (intermediate group, final lens group) L6 6th lens group (final lens group)

Claims

1. A zoom lens comprising a first lens group with positive refractive power that does not move for zooming and is arranged sequentially from the object side to the image side, an intermediate group consisting of two or three lens groups that move for zooming, a lens group with positive refractive power that moves for zooming, and a final lens group with positive refractive power that does not move for zooming, For zooming, the spacing between each set of adjacent lens groups changes. The intermediate group has at least one negative refractive power lens group including at least three lenses, The lens group V closest to the object among the at least one negative refractive power lens group has at least one positive lens and at least one negative lens, and the lens closest to the object in the lens group V is the negative lens. Let n_nf be the refractive index of the negative lens closest to the object in the lens group V, θ_pr and v_pr be the partial dispersion ratio and Abbe number of the positive lens closest to the image in the lens group V, respectively, let f1 be the focal length of the first lens group, and f2 be the focal length of the lens group V. 1.930<n_nf<2.200 0.648<θ_pr+0.00253×v_pr<0.678 -1.88≦f1 / f2<-1.00 A zoom lens characterized by satisfying the following conditional equation.

2. Let fw be the focal length of the zoom lens at the wide-angle end. -2.50<f2 / fw<0.00 The zoom lens according to claim 1, characterized in that it satisfies the following condition.

3. Let f21 be the focal length of the lens closest to the object in the aforementioned lens group V. 0.70<f21 / f2<2.00 The zoom lens according to claim 1, characterized in that it satisfies the following condition.

4. Let n_ave be the average refractive index of all the lenses included in the lens group V. 1.70<n_ave<2.00 The zoom lens according to claim 1, characterized in that it satisfies the following condition.

5. Let v be the Abbe number. The lens group V is: 60 < v < 100 The zoom lens according to claim 1, characterized by having a negative lens that satisfies the following condition.

6. Let v_pave and θ_pave be the average Abbe number and average partial variance ratio of all positive lenses included in the lens group V, respectively, and let v_nave and θ_nave be the average Abbe number and average partial variance ratio of all negative lenses included in the lens group V, -0.0025<(θ_pave-θ_nave) / (v_pave-v_nave)<0.0000 The zoom lens according to claim 1, characterized in that it satisfies the following condition.

7. The zoom lens according to claim 1, characterized in that the lens closest to the image in the lens group V is a negative lens, and the second lens from the image side in the lens group V is a positive lens.

8. Let v_nr and θ_nr be the Abbe number and partial dispersion ratio of the image-side lens among the negative lenses included in the lens group V, respectively. -0.0030<(θ_pr-θ_nr) / (v_pr-v_nr)<0.0000 The zoom lens according to claim 1, characterized in that it satisfies the following condition.

9. The zoom lens according to claim 1, characterized in that the lens group V consists of four lenses.

10. The first lens group comprises a first sub-lens group with negative refractive power, a second sub-lens group with positive refractive power, and a third sub-lens group with positive refractive power, arranged in order from the object side to the image side. For focusing, the spacing between each set of adjacent sub-lens groups changes. The zoom lens according to claim 1, characterized in that the first sub-lens group does not move for focusing, the second sub-lens group moves for focusing, and the third sub-lens group does not move for focusing.

11. The aforementioned intermediate group consists of a second lens group and a third lens group, arranged in order from the object side to the image side. The zoom lens according to claim 1, characterized in that the lens group V is the second lens group.

12. The aforementioned intermediate group consists of a second lens group, a third lens group, and a fourth lens group, arranged in order from the object side to the image side. The zoom lens according to claim 1, characterized in that the lens group V is the third lens group.

13. A zoom lens comprising: a first lens group with positive refractive power that does not move for zooming and is arranged in order from the object side to the image side; an intermediate group consisting of two or three lens groups that move for zooming; a lens group with positive refractive power that moves for zooming; and a final lens group with positive refractive power that does not move for zooming, For zooming, the spacing between each set of adjacent lens groups changes. The intermediate group has at least one negative refractive power lens group including at least three lenses, The lens group V closest to the object among the at least one negative refractive power lens group has at least one positive lens and at least one negative lens, and the lens closest to the object in the lens group V is the negative lens. Let n_nf be the refractive index of the negative lens closest to the object in the lens group V, θ_pr and v_pr be the partial dispersion ratio and Abbe number of the positive lens closest to the image in the lens group V, respectively, let f1 be the focal length of the first lens group, and f2 be the focal length of the lens group V. 1.930<n_nf<2.200 0.648<θ_pr+0.00253×v_pr<0.678 -3.00<f1 / f2<-1.00 The following condition is satisfied: Let v be the Abbe number. The lens group V is: 60 < v < 100 A zoom lens characterized by having a negative lens that satisfies the following condition.

14. A zoom lens comprising: a first lens group with positive refractive power that does not move for zooming and is arranged in order from the object side to the image side; an intermediate group consisting of two or three lens groups that move for zooming; a lens group with positive refractive power that moves for zooming; and a final lens group with positive refractive power that does not move for zooming, For zooming, the spacing between each set of adjacent lens groups changes. The intermediate group has at least one negative refractive power lens group including at least three lenses, The lens group V closest to the object among the at least one negative refractive power lens group has at least one positive lens and at least one negative lens, and the lens closest to the object in the lens group V is the negative lens. Let n_nf be the refractive index of the negative lens closest to the object in the lens group V, θ_pr and v_pr be the partial dispersion ratio and Abbe number of the positive lens closest to the image in the lens group V, f1 be the focal length of the first lens group, f2 be the focal length of the lens group V, v_pave and θ_pave be the average Abbe number and average partial dispersion ratio of all positive lenses included in the lens group V, and v_nave and θ_nave be the average Abbe number and average partial dispersion ratio of all negative lenses included in the lens group V, 1.930<n_nf<2.200 0.648<θ_pr+0.00253×v_pr<0.678 -3.00<f1 / f2<-1.00 -0.0025<(θ_pave-θ_nave) / (v_pave-v_nave)<0.0000 A zoom lens characterized by satisfying the following conditional equation.

15. A zoom lens comprising: a first lens group with positive refractive power that does not move for zooming and is arranged in order from the object side to the image side; an intermediate group consisting of two or three lens groups that move for zooming; a lens group with positive refractive power that moves for zooming; and a final lens group with positive refractive power that does not move for zooming, For zooming, the spacing between each set of adjacent lens groups changes. The intermediate group has at least one negative refractive power lens group including at least three lenses, The lens group V closest to the object among the at least one negative refractive power lens group has at least one positive lens and at least one negative lens, and the lens closest to the object in the lens group V is the negative lens. Let n_nf be the refractive index of the negative lens closest to the object in the lens group V, θ_pr and v_pr be the partial dispersion ratio and Abbe number of the positive lens closest to the image in the lens group V, respectively, f1 be the focal length of the first lens group, f2 be the focal length of the lens group V, and v_rn and θ_rn be the Abbe number and partial dispersion ratio of the negative lens closest to the image in the lens group V, respectively. 1.930<n_nf<2.200 0.648<θ_pr+0.00253×v_pr<0.678 -3.00<f1 / f2<-1.00 -0.0030<(θ_pr-θ_nr) / (v_pr-v_nr)<0.0000 A zoom lens characterized by satisfying the following conditional equation.

16. A zoom lens comprising: a first lens group with positive refractive power that does not move for zooming and is arranged in order from the object side to the image side; an intermediate group consisting of two or three lens groups that move for zooming; a lens group with positive refractive power that moves for zooming; and a final lens group with positive refractive power that does not move for zooming, For zooming, the spacing between each set of adjacent lens groups changes. The intermediate group has at least one negative refractive power lens group including at least three lenses, The lens group V closest to the object among the at least one negative refractive power lens group has at least one positive lens and at least one negative lens, and the lens closest to the object in the lens group V is the negative lens. Let n_nf be the refractive index of the negative lens closest to the object in the lens group V, θ_pr and v_pr be the partial dispersion ratio and Abbe number of the positive lens closest to the image in the lens group V, respectively, let f1 be the focal length of the first lens group, and f2 be the focal length of the lens group V. 1.930<n_nf<2.200 0.648<θ_pr+0.00253×v_pr<0.675 -3.00<f1 / f2<-1.00 A zoom lens characterized by satisfying the following conditional equation.

17. A zoom lens according to any one of claims 1 to 16, An imaging device characterized by having an image sensor that captures an image formed by the zoom lens.

Images