System, imaging device including the system, and lens device including the system

Abstract

The disclosure relates to a system, an imaging device including the system, and a lens device including the system. A system includes, in order from an object side to an image side, a front unit having a negative refractive power, an aperture stop, a rear unit having a positive refractive power, and at least ten lenses. The rear unit includes an aspherical lens having an inflection point, and when the focal length of the system as a whole is represented by f, the focal length of the front unit is represented by f1, the maximum image height of the system is represented by ImgH, and the total length of the system is represented by L, the system satisfies a predetermined inequality.

Description

Technical Field

[0001] The embodiments relate to a system suitable for digital still cameras, digital video cameras, surveillance cameras, vehicle cameras, smartphone cameras, etc., an imaging device including the system, and a lens device including the system. Background Technology

[0002] In wide-angle optical systems, distortions and aberrations generated in the optical system can be corrected by setting the lens unit relative to the aperture on the object side. Japanese Patent Publication No. 2023-184065 discloses a wide-angle optical system in which a front lens unit with negative refractive power, an aperture stop, and a rear lens unit with positive refractive power are arranged sequentially from the object side. Summary of the Invention

[0003] A system comprising, from the object side to the image side, a front unit with negative refractive power, an aperture stop, a rear unit with positive refractive power, and at least ten lenses, wherein the rear unit includes an aspherical lens with an inflection point, and the following inequality is satisfied:

[0004] -2.98 < f1 / f < 0.00

[0005] 0.40 < ImgH / L

[0006] Where f represents the overall focal length of the system, f1 represents the focal length of the front unit, ImgH represents the maximum image height of the system, and L represents the total length of the system.

[0007] The features of this disclosure will become apparent from the following description of embodiments with reference to the accompanying drawings. The following description of embodiments is by way of example. Attached Figure Description

[0008] Figure 1 This is a cross-sectional view of the optical system in Example 1 during focusing at infinity.

[0009] Figure 2 This is the longitudinal aberration map corresponding to Example 1.

[0010] Figure 3 This is a cross-sectional view of the optical system in Example 2 during infinity focusing.

[0011] Figure 4 This is the longitudinal aberration map corresponding to Example 2.

[0012] Figure 5 This is a cross-sectional view of the optical system in Example 3 during infinity focusing.

[0013] Figure 6 This is the longitudinal aberration map corresponding to Example 3.

[0014] Figure 7 This is a cross-sectional view of the optical system in Example 4 during infinity focusing.

[0015] Figure 8 This is the longitudinal aberration map corresponding to Example 4.

[0016] Figure 9 This is a schematic diagram related to the hit point of off-axis rays on an optical surface.

[0017] Figure 10 This is a schematic diagram of an imaging device that uses one of the optical systems in Examples 1 to 4.

[0018] Figure 11 This is a schematic diagram of a lens device that uses one of the optical systems in Examples 1 to 4. Detailed Implementation

[0019] The embodiments disclosed in the specification will be described in detail below with reference to the accompanying drawings. In the drawings, the same components are given the same reference numerals, and repeated descriptions thereof will be omitted.

[0020] Figure 1 , Figure 3 , Figure 5 and Figure 7 These are cross-sectional views of the optical systems L0 of Examples 1 through 4 during infinity focusing. The optical systems L0 of each example will be used in imaging devices such as digital still cameras, digital video cameras, surveillance cameras, or vehicle-mounted cameras.

[0021] In the cross-sectional views, the left side is the object side, and the right side is the image side. The optical system L0 in each example includes multiple lens units. Note that a lens unit in the specification refers to a group of lenses isolated from each other by an aperture stop SP. Furthermore, each lens unit may consist of one lens or multiple lenses. Additionally, each lens unit may include aspherical lenses, Fresnel lenses, superlenses, diffractive optical elements, etc.

[0022] In the optical system L0 of each example, among the lens units included in the optical system L0, Li represents the i-th lens unit (i is a natural number) counted from the object side. Furthermore, among the lenses included in the optical system, Gk represents the k-th lens (k is a natural number) counted from the object side.

[0023] In the optical system L0 of each example, L1 (LF) represents the front unit of the lens unit positioned on the object side relative to the aperture stop. Furthermore, L2 (LR) represents the rear unit of the lens unit positioned on the image side relative to the aperture stop.

[0024] In each cross-sectional view, SP is the aperture stop. Furthermore, FL is an optical element corresponding to optical filters, low-pass filters, infrared cut-off filters, etc. IP is the image plane, and when the optical system L0 of each example is used as the imaging optical system of a digital still camera or digital video camera, the imaging surface of the solid-state image sensing device (such as a CCD sensor or CMOS sensor) is arranged on the image plane IP. When the optical system L0 of each example is used as the imaging optical system of a silver halide film camera, the image plane IP serves as the photosensitive surface corresponding to the film surface. Note that the optical system in each example can be used as a projection lens for a projector, etc. In this case, the left side is the screen side, and the right side is the projected image side.

[0025] Figure 2 , Figure 4 , Figure 6 and Figure 8 These are aberration diagrams of the optical systems L0 in Examples 1 through 4 during infinity focusing. In each diagram, from left to right, spherical aberration, astigmatic aberration, distortion aberration, and magnification chromatic aberration are indicated. In the spherical aberration diagram, Fno. is the F-number, the solid line indicates the d-line (wavelength 587.6 nm), and the double-dotted line indicates the amount of spherical aberration relative to the g-line (wavelength 435.8 nm). In the astigmatic aberration diagram, the solid line indicates the sagittal image plane, and the dashed line indicates the field curvature of the meridional image plane. In the distortion aberration diagram, the amount of distortion aberration relative to the d-line is indicated. In the magnification chromatic aberration diagram, the chromatic aberration at the g-line is illustrated. Furthermore, ω is the half-angle […]. ].

[0026] Here, the off-axis focal lengths used in each example will be described. For an optical system L0 with an on-axis focal length of f0, the maximum half-angle of view is ω[ When the focal length is at an angle ω relative to the optical axis, the off-axis focal length is... The focal length for the off-axis ray when it passes through the center of the aperture stop SP and forms an image on the image side.

[0027] Figure 9 The diagram illustrates the method for calculating off-axis focal length. Figure 9 In this context, Gi represents an optical surface, such as a lens surface. The optical axis at this surface is oriented in the Z direction. Among the directions orthogonal to the Z direction, the two directions orthogonal to each other are the X and Y directions. When the Z direction is parallel to the horizontal direction, the X direction is also parallel to the horizontal direction, and the Y direction is parallel to the vertical direction.

[0028] exist Figure 9 In the equation, the point where the on-axis ray intersects the optical surface Gi is hp_0. Furthermore, at the maximum viewing angle ω[ The point of intersection between the incoming off-axis ray and the optical surface Gi is the point of impact hp_ω. When calculating the curvature near the off-axis principal ray at the point of impact hp_ω, this curvature varies depending on the azimuth angle. As described in Reference 1 below, the focal length for the off-axis principal ray can be obtained by calculating the curvature at the point of impact.

[0029] (Reference 1) Keisuke Araki, “Extension of Non-Co-Axial Optics into the Imaging Systems”, Japanese Journal of Optics, the Optical Society of Japan, June 2008, Vol. 37, No. 6, pp. 334-339

[0030] Next, the characteristic components of the optical system L0 for each example will be described.

[0031] The optical system L0 in each example includes, from the object side, a front unit L1 with negative refractive power, an aperture stop SP, and a rear unit L2. Because the front unit L1 has negative refractive power, the optical system L0 has a so-called retrofocus configuration, and the principal point is therefore arranged on the image side, thus ensuring backfocus. Furthermore, the size of the optical system L0 can be reduced in the radial direction.

[0032] Each example optical system L0 includes an aspherical lens (lens A). Furthermore, in each example optical system L0, the aspherical lens included in the rear unit L2 has an inflection point on its lens surface. An inflection point on the lens surface is the point where the sign of the lens's refractive power changes from the portion near the optical axis of the lens surface towards the peripheral portion of the lens surface. Including an aspherical lens with an inflection point allows for good correction of field curvature and astigmatism aberrations.

[0033] Note that an example of an aspherical lens with an inflection point is an aspherical lens with a lens shape such that the object-side lens surface of the aspherical lens includes a convex portion near the optical axis on the object side and a concave peripheral portion on the object side. Similarly, the image-side lens surface of this aspherical lens includes a concave portion near the optical axis on the image side and a convex peripheral portion on the image side. Therefore, Petzval aberrations can be corrected at the portion near the optical axis of the aspherical lens while astigmatism is corrected at the peripheral portion. Note that the object-side lens surface of this aspherical lens is not limited to this and may include a concave portion near the optical axis on the object side and a convex peripheral portion on the object side. Similarly, the image-side lens surface of this aspherical lens may include a concave portion near the optical axis on the image side and a convex peripheral portion on the image side.

[0034] Furthermore, the optical system L0 of each example is characterized by satisfying the following inequality (1), where f represents the focal length of the optical system L0 as a whole.

[0035]

[0036] Inequality (1) defines the focal length of the front unit L1 relative to the focal length of the optical system L0 as a whole. By satisfying inequality (1), the formability of the lenses constituting the front unit L1 can be improved, while various aberrations can be corrected well. When the focal length of the front unit L1 is less than the lower limit of inequality (1), the absolute value of the negative refractive power of the front unit L1 decreases. At this time, in order to achieve both the correction of distortion aberrations and the correction of field curvature, it is necessary to increase the thickness deviation ratio of each lens constituting the front unit L1, which is not preferred because the formability of the lens is reduced. When the focal length of the front unit L1 is greater than the upper limit of inequality (1), the correction of distortion aberrations and field curvature is difficult, which is not preferred because the front unit L1 has positive refractive power.

[0037] Furthermore, in one embodiment, the range of values ​​in inequality (1) is set to the range in the following inequality (1a).

[0038]

[0039] In addition, in another embodiment, the range of values ​​in inequality (1) is set to the range in the following inequality (1b).

[0040]

[0041] Next, the conditions that the optical systems L0 in each example must satisfy will be described.

[0042] When the maximum image height of the optical system L0 is represented by ImgH and its total optical length is represented by L, in one embodiment, the following inequality (2) is satisfied.

[0043]

[0044] Inequality (2) defines the ratio between the maximum image height of the optical system L0 and the total optical length. Here, the maximum image height of the optical system L0 refers to the distance from the position on the image plane IP with a peripheral illuminance of 10% to the optical axis when the illuminance at a position on the optical axis is 100%. Furthermore, the total optical length L of the optical system L0 refers to the distance along the optical axis from the surface vertex of the object-side lens surface of the first lens G1, which is included in the front unit L1 and is closest to the object, to the image plane. When this ratio is less than the lower limit of inequality (2), the total length of the optical system L0 increases, which is not preferred because the size of the optical system increases. In addition, in one embodiment, the upper limit of inequality (2) is set to 3.00, 2.95, 2.90, 2.85, 2.80, 2.75, 2.70, 2.65, 2.60, 2.55, or 2.50 to ensure the total length of the optical system used to properly correct various aberrations. In another embodiment, the upper limit of inequality (2) is set to 2.45, 2.40, 2.35, 2.30, 2.25, 2.20, 2.15, 2.10, 2.05 or 2.00.

[0045] When the focal length of the first lens G1, which is closest to the object in the optical system L0, is represented by fG1, in one embodiment, the following inequality (3) is satisfied.

[0046]

[0047] Inequality (3) defines the focal length of the front unit L1 and the focal length of the first lens G1, which is included in the front unit L1 and is positioned closest to the object. When the focal lengths are less than the lower limit of inequality (3), barrel distortion aberration is strongly generated, which is not preferred. Furthermore, in one embodiment, the upper limit of inequality (3) is set to 2.00, 1.95, 1.90, 1.85, 1.80, 1.75, 1.70, 1.65, 1.60, 1.55, or 1.50 to properly correct for distortion aberration.

[0048] When the off-axis focal length of the current unit L1 in the meridional direction is represented by fω1, in one embodiment, the following inequality (4) is satisfied.

[0049]

[0050] Inequality (4) defines the ratio between the on-axis focal length and the off-axis focal length of the front unit L1. When this ratio is less than the lower limit of inequality (4), the refractive power of the front unit L1 for off-axis rays is weaker than that for paraxial rays, and it allows for strong barrel distortion aberration and field curvature, which is not preferred. When this ratio is greater than the upper limit of inequality (4), it is difficult to reduce the total length of the optical system L0, which is also not preferred because the off-axis focal length of the front unit L1 has a positive refractive power.

[0051] In one embodiment, when the focal length of the lens GR included in the rear unit L2 and closest to the image setting is represented by fGR and the focal length of the rear unit L2 is represented by f2, the following inequality (5) is satisfied.

[0052]

[0053] Inequality (5) defines the range of focal lengths of the lens GR closest to the image setting in the optical system L0. When this range is less than the lower limit of inequality (5), the negative refractive power of the lens GR relative to the rear unit L2 is too weak. As a result, the back focal length of the optical system L0 increases, and the total length of the optical system L0 increases, which is not preferred. When this range is greater than the upper limit of inequality (5), the negative refractive power of the lens GR relative to the rear unit L2 is too strong. As a result, the back focal length of the optical system L0 decreases, and the image plane IP and the lens GR are too close to each other, which is not preferred.

[0054] When the half-angle of the optical system L0 is represented by ω, in one embodiment, the following inequality (6) is satisfied.

[0055]

[0056] Inequality (6) defines the range of the half-angle of the optical system L0. When this range is less than the lower limit of inequality (6), distortion aberrations and field curvature are overcorrected, which is not preferred. When this range is greater than the upper limit of inequality (6), barrel distortion aberrations and field curvature are strongly generated, which is also not preferred.

[0057] When the material of the negative lens GN1, which is included in the rear unit L2 and is positioned closest to the object, is represented by νd with respect to the Abbe number of the d-line, in one embodiment, the following inequality (7) is satisfied.

[0058]

[0059] Inequality (7) defines the range of Abbe numbers for the material of the negative lens GN1. When the Abbe number is less than the lower limit of inequality (7), the on-axis chromatic aberration is overcorrected, which is not preferred. When the Abbe number is greater than the upper limit of inequality (7), the on-axis chromatic aberration is not adequately corrected, which is also not preferred.

[0060] Furthermore, when the refractive index of the material of the negative lens GN1 relative to the d line is represented by nd, in one embodiment, the following inequality (8) is satisfied.

[0061]

[0062] Inequality (8) defines the range of the refractive index of the material of the negative lens GN1. When this range is less than the lower limit of inequality (8), spherical aberration is not adequately corrected, which is not preferred. When this range is greater than the upper limit of inequality (8), spherical aberration is overcorrected, which is also not preferred.

[0063] Furthermore, in one embodiment, the numerical ranges in inequalities (2) to (8) are respectively set to the ranges in the following inequalities (2a) to (8a).

[0064]

[0065] Furthermore, in yet another embodiment, the numerical ranges in inequalities (2) to (8) are respectively set to the ranges in the following inequalities (2b) to (8b).

[0066]

[0067] Next, the configurations that the optical system L0 in each example must satisfy will be described.

[0068] In one embodiment, the optical system L0 of each example includes at least ten lenses. The sensitivity of each lens can be increased by allowing the refractive force to be distributed among the lenses.

[0069] In the optical systems L0 of each example, the front unit L1 includes at least three lenses. Therefore, distortion aberrations in the front unit L1 can be well corrected while ensuring that the number of lenses allows the optical system to have a wide angle.

[0070] In the optical system L0 of each example, the front unit L1 includes a positive lens. Because the rear unit L2 as a whole has positive refractive power, a lens with positive refractive power is provided on each of the object side and image side of the aperture stop SP due to the positive lens provided in the front unit L1. Therefore, field curvature and distortion aberrations can be well corrected.

[0071] In one embodiment, one of the object-side and image-side lens surfaces of at least one lens included in the optical system L0 of each example is an aspherical surface. In particular, using an aspherical surface as the lens surface of the lens G1 included in the front unit L1 and positioned closest to the object is preferred because the incident angle of off-axis rays entering the lens G1 is small, which is advantageous for correcting distortion aberrations and ensuring peripheral illumination. Note that, to enhance the above effects, it is more preferable that both the object-side and image-side lens surfaces of the lens G1 are aspherical surfaces.

[0072] In the optical system L0 of each example, a positive lens, another positive lens, and a negative lens are arranged sequentially in the rear unit L2, starting from the position closest to the object. By placing the positive lens near or on the image side of the aperture stop SP, the light rays that have entered the rear unit L2 can be converged, and the distance from the aperture stop SP to the image plane can be reduced.

[0073] In the optical systems L0 of each example, the object-side lens surface of the lens GR closest to the image setting includes a convex portion near the optical axis and a concave peripheral portion. Similarly, the image-side lens surface of the lens GR includes a concave portion near the optical axis and a convex peripheral portion. Therefore, astigmatism can be corrected at the peripheral portion while correcting for Pessval's aberrations near the optical axis.

[0074] Furthermore, in one embodiment, it is preferable to use a lens (lens B) made of resin material as the lens included in the optical system L0, because it is possible to achieve an aspherical lens shape with an inflection point, as described above.

[0075] Next, the detailed configurations of Examples 1 to 4 will be described. Note that for the optical system L0 of each example, the description of configurations identical to those of the optical system L0 in Example 1 will be omitted, and the differences from Example 1 will be the main focus.

[0076] Examples 1 to 3

[0077] In Examples 1 to 3, the optical system L0 consists, from the object side, a front unit L1 with negative refractive power, an aperture stop SP, and a rear unit L2 with positive refractive power. Because the front unit L1 has negative refractive power, the optical system L0 has a so-called back-shifted configuration, and the principal point is thus arranged on the image side, which allows the size of the optical system L0 to be reduced in the radial direction while ensuring the back focal length.

[0078] In the optical system L0 of each of Examples 1 to 3, the front unit L1 consists of lenses G1 to G3, and the rear unit L2 consists of lenses G4 to G10. Furthermore, an optical filter FL is provided on the image side of the rear unit L2.

[0079] In the optical system L0 of each of Examples 1 to 3, the object-side lens surface and image-side lens surface of the lens G1, which is located in the front unit L1 and closest to the object, each have an aspherical surface shape. Therefore, the incident angle of off-axis rays entering the lens G1 is small, which is advantageous for correcting distortion aberrations and ensuring peripheral illumination.

[0080] In the optical system L0 of each of Examples 1 to 3, a positive lens, another positive lens, and a negative lens are sequentially arranged in the rear unit L2, starting from the position closest to the object. Therefore, because the aperture stop SP has positive refractive power near and above the image side, the light rays that have entered the rear unit L2 can be converged, and the distance between the aperture stop SP and the image plane can be reduced.

[0081] In the optical system L0 of each of Examples 1 to 3, the front unit L1 includes a positive lens G3. Therefore, a lens with positive refractive power is provided on each of the object side and image side of the aperture stop SP, and thus field curvature and distortion aberrations can be well corrected.

[0082] In the optical system L0 of each of Examples 1 to 3, the object-side lens surface of the lens GR closest to the image in the rear unit L2 includes a convex portion near the optical axis and a concave peripheral portion on the object side. Similarly, the image-side lens surface of the lens GR includes a concave portion near the optical axis and a convex peripheral portion on the image side. Therefore, astigmatism can be corrected at the peripheral portion while correcting for Pessvality near the optical axis of the lens GR. Furthermore, the lens GR1, which is disposed adjacent to the object side of the lens GR, and the negative lens GN1, which is closest to the object among the negative lenses included in the rear unit L2, each have a lens shape similar to that of the lens GR.

[0083] In the optical system L0 of each of Examples 1 to 3, the negative lens GN1, which is included in the rear unit L2 and is positioned closest to the object, is a lens made of resin material. Therefore, the formability of the negative lens GN1 is improved, and it is possible to form the negative lens GN1 into an aspherical lens shape with an inflection point.

[0084] Example 4

[0085] In the optical system L0 of Example 4, the front unit L1 consists of four lenses, G1 to G4, and the rear unit L2 consists of seven lenses, G5 to G11. Furthermore, an optical filter FL is provided on the image side of the rear unit L2.

[0086] In the optical system L0 of Example 4, three negative lenses are sequentially arranged in the front unit L1, starting from the position closest to the object. To ensure sufficient back focal length in the wide-angle optical system, a strong negative refractive force is applied to the object side of the optical system. By allowing this negative refractive force to be distributed among the three negative lenses, the refractive force of each negative lens can be reduced. Therefore, barrel distortion and field curvature can be suppressed.

[0087] Next, the numerical examples 1 to 4 corresponding to Examples 1 to 4 are presented below.

[0088] In the surface data of each numerical example, r (mm) represents the radius of curvature of each optical surface, and d (mm) represents the distance along the optical axis between the k-th surface and the (k+1)-th surface. Note that k is the surface number counted from the object side. Furthermore, nd represents the refractive index of the material of each optical component relative to the d-line, and νd represents the Abbe number of the material of each optical component. Here, when nC, nd, and nF represent the refractive indices of the Fraunhofer lines c-line (656.3 nm), d-line (587.56 nm), and F-line (486.1 nm), respectively, the Abbe number νd is expressed by the following expression.

[0089]

[0090] Note that in each numerical example, the half-angle of the optical system L0 is indicated ( The maximum image height corresponding to the half-angle is indicated as "image height". Additionally, in each numerical example, the focal length of each lens unit at the d-line is indicated as lens unit data. Note that d, focal length (mm), F-number, and half-angle (mm) are... The values ​​are those of the optical system L0 in each example when focused at infinity. BF (back focal length) represents the value obtained by converting the distance along the optical axis from the rearmost lens surface (the surface closest to the image) to the paraxial image plane into a value in air. The total lens length is the length obtained by adding the back focal length to the distance along the optical axis from the object-side lens surface of the lens closest to the object among the lenses included in the optical system L0 to the image-side lens surface of the lens closest to the image.

[0091] Furthermore, an asterisk (*) is placed to the right of the surface number of each aspherical lens surface. When X represents the displacement from the surface vertex in the optical axis direction, h represents the height from the optical axis in the direction perpendicular to the optical axis, R represents the exaxial radius of curvature, k represents the conic constant, and A4, A6, A8, A10, A12, A14, A16, A18, and A20 each represent the aspherical surface coefficients of each order, the shape of the aspherical surface is expressed by the following formula.

[0092]

[0093] "In each aspherical surface coefficient" "mean" ".

[0094] Numerical Example 1

[0095] Unit: mm

[0096] Surface data

[0097] Surface number rd nd νd Effective diameter

[0098] 1* 4.859 0.62 1.54400 56.0 5.21

[0099] 2* 2.086 0.21 3.83

[0100] 3* 2.140 0.50 1.69800 16.3 3.39

[0101] 4* 1.505 0.45 2.65

[0102] 5* 1.979 0.37 1.62100 23.6 2.05

[0103] 6* 2.928 (variable) 1.61

[0104] 7 (Aperture) ∞ 0.12 1.43

[0105] 8* -5.227 0.37 1.59100 27.2 1.44

[0106] 9* -2.331 -0.04 1.60

[0107] 10* -14.675 0.71 1.54400 56.0 1.72

[0108] 11* -1.644 0.12 2.00

[0109] 12* -5.650 0.37 1.59100 27.2 2.11

[0110] 13* 6.521 0.37 2.42

[0111] 14* -4.439 0.37 1.69800 16.3 2.51

[0112] 15* -5.673 0.12 3.19

[0113] 16* -15.042 0.77 1.54400 56.0 3.87

[0114] 17* -2.385 0.12 4.44

[0115] 18* 2.800 0.87 1.54400 56.0 5.27

[0116] 19* 2.959 0.25 5.83

[0117] 20* 9.650 0.71 1.70500 14.0 6.30

[0118] 21* 3.941 0.38 7.10

[0119] 22 ∞ 0.26 1.51700 64.2 7.72

[0120] 23 ∞ (variable) 7.81

[0121] Image plane ∞

[0122] Aspherical surface data

[0123] First surface

[0124] K = 0.00000e+00, A4 = -6.22726e-03, A6 = 2.49307e-03, A8 = -3.64351e-04, A10 = 3.52612e-05, A12 = -1.60799e-06

[0125] Second surface

[0126] K = 0.00000e+00, A4 = -6.31637e-03, A6 = -7.54161e-03, A8 = 4.00579e-03, A10 = -1.04685e-03

[0127] Third Surface

[0128] K = 0.00000e+00, A4 = 3.88578e-02, A6 = -2.24306e-02, A8 = 6.14943e-03, A10 = -1.93389e-03, A12 = 1.03603e-04

[0129] Fourth surface

[0130] K = 0.00000e+00, A4 = 4.75101e-02, A6 = -4.04733e-02, A8 = -9.32003e-03, A10 = -1.56527e-03

[0131] Fifth Surface

[0132] K = 0.00000e+00, A4 = 6.04506e-02, A6 = 1.06399e-02

[0133] Sixth Surface

[0134] K = 0.00000e+00, A4 = 9.61786e-02, A6 = 2.13213e-01, A8 = -4.47519e-01, A10 = 4.46135e-01

[0135] A18 = -5.15324e-01, A20 = 1.37029e-01

[0136] Eighth surface

[0137] K = 0.00000e+00, A4 = -9.37315e-02, A6 = -1.20621e-01

[0138] Ninth Surface

[0139] K = 0.00000e+00, A4 = 1.21352e-01, A6 = -3.85874e-01, A8 = -7.05670e-01, A10 = 6.83274e+00, A12 = -2.23937e+01, A14 = 4.22889e+01, A16 = -4.74471e+01

[0140] A18 = 2.95638e+01, A20 = -7.91667e+00

[0141] Tenth Surface

[0142] K = 0.00000e+00, A4 = 2.84988e-01, A6 = -5.32788e-01, A8 = 2.28548e-01, A10 = 2.74332e+00, A12 = -1.07381e+01, A14 = 2.03426e+01, A16 = -2.15153e+01

[0143] A18 = 1.20411e+01, A20 = -2.76919e+00

[0144] Eleventh Surface

[0145] K = 0.00000e+00, A4 = -3.24436e-02, A6 = -5.91821e-04

[0146] Twelfth Surface

[0147] K = 0.00000e+00, A4 = -3.47386e-01, A6 = 1.67850e-01

[0148] Thirteenth Surface

[0149] K = 0.00000e+00, A4 = -2.73129e-01, A6 = -8.79136e-04, A8 = 4.79035e-01, A10 = -1.38435e+00, A12 = 2.28912e+00, A14 = -2.33036e+00, A16 = 1.44741e+00

[0150] A18 = -5.04487e-01, A20 = 7.62655e-02

[0151] Fourteenth Surface

[0152] K = 8.11732e+00, A4 = -1.16111e-02, A6 = -9.04062e-02, A8 = 1.54999e-01, A10 = -4.17454e-01, A12 = 7.33737e-01, A14 = -8.04871e-01, A16 =5.33042e-01

[0153] A18 = -1.98497e-01, A20 = 3.21986e-02

[0154] The Fifteenth Surface

[0155] K = -1.00000e+00, A4 = -2.98752e-02, A6 = 1.36617e-02, A8 = -2.70764e-02, A10 = 3.50423e-02, A12 = -3.00282e-02, A14 = 1.50734e-02, A16 =-4.36035e-03

[0156] A18 = 7.19102e-04, A20 = -5.68105e-05

[0157] Sixteenth Surface

[0158] K = 0.00000e+00, A4 = 5.76356e-02, A6 = -1.45974e-02

[0159] The Seventeenth Surface

[0160] K = 0.00000e+00, A4 = 6.65221e-02, A6 = 8.95717e-03, A8 = -6.67550e-03, A10 = 7.80982e-04

[0161] The Eighteenth Surface

[0162] K = 0.00000e+00, A4 = -5.00789e-02, A6 = 3.86987e-03, A8 = -3.64654e-04

[0163] The Nineteenth Surface

[0164] K = 0.00000e+00, A4 = -4.49372e-02, A6 = 2.22702e-03, A8 = -1.30128e-04, A10 = 4.81439e-05, A12 = -6.92656e-06

[0165] 20th Surface

[0166] K = 0.00000e+00, A4 = -1.12949e-02, A6 = -3.05329e-03, A8 = 1.35380e-03, A10 = -1.91853e-04, A12 = 1.10320e-05, A14 = -2.75407e-07, A16 =6.58006e-09

[0167] Surface number twenty-one

[0168] K = 0.00000e+00, A4 = -3.51306e-02, A6 = 5.10806e-03, A8 = -5.06655e-04, A10 = 2.25555e-05, A12 = -2.41588e-07, A14 = -8.18507e-10, A16 = -6.12513e-10

[0169] Various data

[0170] Focal length 3.05

[0171] F number 2.21

[0172] Half-angle view 51.80

[0173] Like the height of 3.88

[0174] Total lens length 9.00

[0175] BF 0.56

[0176] Lens unit data

[0177] unit initial surface focal length

[0178] L1 1 -7.27

[0179] L2 7 2.52

[0180] Single lens data

[0181] Lens starting surface focal length

[0182] G1 1 -7.30

[0183] G2 3 -10.73

[0184] G3 5 8.54

[0185] G4 8 6.79

[0186] G5 11 3.34

[0187] G6 13 -5.06

[0188] G7 15 -33.42

[0189] G8 17 5.10

[0190] G9 19 32.59

[0191] G10 21 -9.96

[0192] Numerical Example 2

[0193] Unit: mm

[0194] Surface data

[0195] Surface number rd nd νd Effective diameter

[0196] 1* 7.603 0.50 1.54400 56.0 5.65

[0197] 2 * 2.188 0.26 4.06

[0198] 3* 2.277 0.57 1.69800 16.3 3.61

[0199] 4* 1.580 0.51 2.80

[0200] 5* 1.919 0.39 1.62100 23.6 2.10

[0201] 6 * 2.936 (variable) 1.62

[0202] 7 (Aperture) ∞ 0.10 1.38

[0203] 8* -5.004 0.34 1.59100 27.2 1.38

[0204] 9* -2.364 -0.04 1.52

[0205] 10* -58.417 0.82 1.54400 56.0 1.68

[0206] 11* -1.567 0.10 2.03

[0207] 12* -6.235 0.33 1.59100 27.2 2.11

[0208] 13* 5.581 0.37 2.43

[0209] 14* -4.238 0.34 1.69800 16.3 2.51

[0210] 15* -6.006 0.12 3.22

[0211] 16* -12.367 0.72 1.54400 56.0 3.86

[0212] 17* -2.300 0.12 4.34

[0213] 18* 2.752 0.87 1.54400 56.0 5.10

[0214] 19* 2.968 0.24 5.83

[0215] 20* 8.650 0.71 1.70500 14.0 6.41

[0216] 21* 3.917 0.38 7.13

[0217] 22 ∞ 0.26 1.51700 64.2 7.61

[0218] 23 ∞ (variable) 7.75

[0219] Image plane ∞

[0220] Aspherical surface data

[0221] First surface

[0222] K = 0.00000e+00, A4 = -2.54223e-03, A6 = 2.33757e-03, A8 = -3.84207e-04, A10 = 3.50458e-05, A12 = -1.32461e-06

[0223] Second surface

[0224] K = 0.00000e+00, A4 = 7.40521e-03, A6 = -1.41320e-02, A8 = 5.86577e-03, A10 = -1.03139e-03

[0225] Third Surface

[0226] K = 0.00000e+00, A4 = 4.76308e-02, A6 = -2.67859e-02, A8 = 8.78811e-03, A10 = -2.38026e-03, A12 = 1.84157e-04

[0227] Fourth surface

[0228] K = 0.00000e+00, A4 = 4.32085e-02, A6 = -3.07918e-02, A8 = -9.48084e-03, A10 = -6.03052e-05

[0229] Fifth Surface

[0230] K = 0.00000e+00, A4 = 2.86233e-02, A6 = 8.52926e-03

[0231] Sixth Surface

[0232] K = 0.00000e+00, A4 = 7.74792e-02, A6 = 1.75679e-01, A8 = -3.64574e-01, A10 = 3.79370e-01

[0233] A18 = -5.15324e-01, A20 = 1.37029e-01

[0234] Eighth surface

[0235] K = 0.00000e+00, A4 = -8.87681e-02, A6 = -1.18145e-01

[0236] Ninth Surface

[0237] K = 0.00000e+00, A4 = 1.15568e-01, A6 = -3.86521e-01, A8 = -6.98859e-01, A10 = 6.69233e+00, A12 = -2.19911e+01, A14 = 4.18834e+01, A16 = -4.75786e+01

[0238] A18 = 3.01112e+01, A20 = -8.20593e+00

[0239] Tenth Surface

[0240] K = 0.00000e+00, A4 = 2.75007e-01, A6 = -5.19088e-01, A8 = 1.94907e-01, A10 = 2.85683e+00, A12 = -1.09850e+01, A14 = 2.08839e+01, A16 = -2.24096e+01

[0241] A18 = 1.27730e+01, A20 = -2.98287e+00

[0242] Eleventh Surface

[0243] K = 0.00000e+00, A4 = -2.23791e-02, A6 = -1.40848e-03

[0244] Twelfth Surface

[0245] K = 0.00000e+00, A4 = -3.62312e-01, A6 = 1.56113e-01

[0246] Thirteenth Surface

[0247] K = 0.00000e+00, A4 = -2.91008e-01, A6 = 4.72921e-03, A8 = 4.75371e-01, A10 = -1.37581e+00, A12 = 2.28965e+00, A14 = -2.34641e+00, A16 = 1.46350e+00

[0248] A18 = -5.11400e-01, A20 = 7.74838e-02

[0249] Fourteenth Surface

[0250] K = 6.24444e+00, A4 = -6.07468e-03, A6 = -9.27356e-02, A8 = 1.54356e-01, A10 = -4.04410e-01, A12 = 7.11676e-01, A14 = -7.80211e-01, A16 =5.15461e-01

[0251] A18 = -1.93139e-01, A20 = 3.16383e-02

[0252] The Fifteenth Surface

[0253] K = -1.00000e+00, A4 = -3.26227e-02, A6 = 1.45332e-02, A8 = -2.15837e-02, A10 = 3.18867e-02, A12 = -3.00215e-02, A14 = 1.50493e-02, A16 =-4.14077e-03

[0254] A18 = 6.42277e-04, A20 = -5.08179e-05

[0255] Sixteenth Surface

[0256] K = 0.00000e+00, A4 = 5.95171e-02, A6 = -1.53097e-02

[0257] The Seventeenth Surface

[0258] K = 0.00000e+00, A4 = 6.83654e-02, A6 = 1.07515e-02, A8 = -7.32994e-03, A10 = 8.46131e-04

[0259] The Eighteenth Surface

[0260] K = 0.00000e+00, A4 = -5.61689e-02, A6 = 5.80887e-03, A8 = -5.52956e-04

[0261] The Nineteenth Surface

[0262] K = 0.00000e+00, A4 = -4.68548e-02, A6 = 3.40289e-03, A8 = -2.48175e-04, A10 = 3.88490e-05, A12 = -4.96182e-06

[0263] 20th Surface

[0264] K = 0.00000e+00, A4 = -1.15333e-02, A6 = -3.03950e-03, A8 = 1.49966e-03, A10 = -2.38658e-04, A12 = 1.75214e-05, A14 = -6.47029e-07, A16 =1.24837e-08

[0265] Surface number twenty-one

[0266] K = 0.00000e+00, A4 = -3.51270e-02, A6 = 5.29599e-03, A8 = -5.16142e-04, A10 = 1.99812e-05, A12 = 3.46321e-08, A14 = -1.78986e-09, A16 = -1.05303e-09

[0267] Various data

[0268] Focal length 2.69

[0269] F number 2.21

[0270] Half-angle view 55.27

[0271] Like the height of 3.88

[0272] Total lens length: 8.83

[0273] BF 0.45

[0274] Lens unit data

[0275] unit initial surface focal length

[0276] L1 1 -6.30

[0277] L2 7 2.40

[0278] Single lens data

[0279] Lens starting surface focal length

[0280] G1 1 -5.84

[0281] G2 3 -11.14

[0282] G3 5 7.77

[0283] G4 8 7.24

[0284] G5 11 2.95

[0285] G6 13 -4.93

[0286] G7 15 -22.40

[0287] G8 17 5.06

[0288] G9 19 28.66

[0289] G10 21 -10.82

[0290] Numerical Example 3

[0291] Unit: mm

[0292] Surface data

[0293] Surface number rd nd νd Effective diameter

[0294] 1* 4.052 0.50 1.54400 56.0 4.97

[0295] 2* 2.130 0.12 3.95

[0296] 3* 2.256 0.40 1.69800 16.3 3.64

[0297] 4* 1.715 0.73 3.03

[0298] 5* 1.915 0.33 1.62100 23.6 1.97

[0299] 6* 2.290 (variable) 1.54

[0300] 7 (Aperture) ∞ 0.10 1.42

[0301] 8* -8.985 0.32 1.59100 27.2 1.42

[0302] 9* -3.828 0.13 1.54

[0303] 10* 126.934 0.85 1.54400 56.0 1.61

[0304] 11* -1.576 0.10 2.05

[0305] 12* -13.008 0.30 1.59100 27.2 2.17

[0306] 13* 3.580 0.30 2.48

[0307] 14* -4.280 0.30 1.69800 16.3 2.55

[0308] 15* -5.779 0.24 3.10

[0309] 16* -17.744 0.63 1.54400 56.0 4.01

[0310] 17* -2.291 0.10 4.34

[0311] 18* 2.732 0.87 1.54400 56.0 4.99

[0312] 19* 3.042 0.35 5.93

[0313] 20* 14.123 0.71 1.70500 14.0 6.84

[0314] 21* 3.877 0.38 7.50

[0315] 22 ∞ 0.26 1.51700 64.2 7.61

[0316] 23 ∞ (variable) 7.75

[0317] Image plane ∞

[0318] Aspherical surface data

[0319] First surface

[0320] K = 0.00000e+00, A4 = -3.07731e-03, A6 = 3.00737e-03, A8 = -8.47144e-04, A10 = 1.21092e-04, A12 = -6.93945e-06

[0321] Second surface

[0322] K = 0.00000e+00, A4 = 2.86153e-02, A6 = -3.02061e-02, A8 = 9.25596e-03, A10 = -1.37869e-03

[0323] Third Surface

[0324] K = 0.00000e+00, A4 = 6.15659e-02, A6 = -4.70842e-02, A8 = 1.50910e-02, A10 = -2.32884e-03, A12 = 2.32308e-05

[0325] Fourth surface

[0326] K = 0.00000e+00, A4 = 3.86307e-02, A6 = -4.60362e-02, A8 = 1.68308e-02, A10 = -4.98505e-03

[0327] Fifth Surface

[0328] K = 0.00000e+00, A4 = 3.66836e-02, A6 = 2.61744e-02

[0329] Sixth Surface

[0330] K = 0.00000e+00, A4 = 8.63360e-02, A6 = 1.36372e-01, A8 = -2.19196e-01, A10 = 2.29418e-01

[0331] A18 = -5.15324e-01, A20 = 1.37029e-01

[0332] Eighth surface

[0333] K = 0.00000e+00, A4 = -1.03223e-01, A6 = -9.83741e-02

[0334] Ninth Surface

[0335] K = 0.00000e+00, A4 = -3.64040e-02, A6 = -1.43447e-01, A8 = -5.71314e-01, A10 = 5.77888e+00, A12 = -2.47397e+01, A14 = 6.16318e+01, A16 =-9.00846e+01

[0336] A18 = 7.18831e+01, A20 = -2.41209e+01

[0337] Tenth Surface

[0338] K = 0.00000e+00, A4 = 1.11675e-01, A6 = -1.51230e-01, A8 = -3.40553e-01, A10 = 3.41133e+00, A12 = -1.18030e+01, A14 = 2.25319e+01, A16 = -2.45121e+01

[0339] A18 = 1.40973e+01, A20 = -3.29067e+00

[0340] Eleventh Surface

[0341] K = 0.00000e+00, A4 = 3.16674e-02, A6 = -3.34507e-02

[0342] Twelfth Surface

[0343] K = 0.00000e+00, A4 = -3.06293e-01, A6 = 1.14326e-01

[0344] Thirteenth Surface

[0345] K = 0.00000e+00, A4 = -2.82012e-01, A6 = -2.15392e-02, A8 = 4.70890e-01, A10 = -1.36401e+00, A12 = 2.26373e+00, A14 = -2.28280e+00, A16 = 1.39120e+00

[0346] A18 = -4.73228e-01, A20 = 6.95500e-02

[0347] Fourteenth Surface

[0348] K = -6.52180e+00, A4 = 1.60212e-02, A6 = -1.14233e-01, A8 = 1.34753e-01, A10 = -3.61854e-01, A12 = 6.51815e-01, A14 = -7.07864e-01, A16 =4.64806e-01

[0349] A18 = -1.75866e-01, A20 = 2.96999e-02

[0350] The Fifteenth Surface

[0351] K = -1.00000e+00, A4 = -2.27112e-02, A6 = 1.02657e-02, A8 = -2.01315e-02, A10 = 3.22438e-02, A12 = -3.06026e-02, A14 = 1.42662e-02, A16 =-3.20216e-03

[0352] A18 = 3.04576e-04, A20 = -5.54668e-06

[0353] Sixteenth Surface

[0354] K = 0.00000e+00, A4 = 6.26857e-02, A6 = -1.40260e-02

[0355] The Seventeenth Surface

[0356] K = 0.00000e+00, A4 = 6.95417e-02, A6 = 1.29310e-02, A8 = -8.04863e-03, A10 = 9.39637e-04

[0357] The Eighteenth Surface

[0358] K = 0.00000e+00, A4 = -5.92072e-02, A6 = 4.64173e-03, A8 = -3.64040e-04

[0359] The Nineteenth Surface

[0360] K = 0.00000e+00, A4 = -3.98586e-02, A6 = 3.65251e-03, A8 = -4.07558e-04, A10 = 3.33785e-05, A12 = -2.86780e-06

[0361] 20th Surface

[0362] K = 0.00000e+00, A4 = -4.90605e-03, A6 = -4.51089e-03, A8 = 1.75998e-03, A10 = -2.96272e-04, A12 = 2.67864e-05, A14 = -1.26658e-06, A16 =2.47217e-08

[0363] Surface number twenty-one

[0364] K = 0.00000e+00, A4 = -3.29180e-02, A6 = 4.26108e-03, A8 = -3.93460e-04, A10 = 1.76042e-05, A12 = -6.00855e-08, A14 = -3.39119e-09, A16 = -9.90108e-10

[0365] Various data

[0366] Focal length 3.02

[0367] F number 2.21

[0368] Half-angle view 52.06

[0369] Like the height of 3.88

[0370] Total lens length: 8.70 mm

[0371] BF 0.45

[0372] Lens unit data

[0373] unit initial surface focal length

[0374] L1 1 -8.21

[0375] L2 7 2.53

[0376] Single lens data

[0377] Lens starting surface focal length

[0378] G1 1 -9.08

[0379] G2 3 -14.67

[0380] G3 5 14.10

[0381] G4 8 11.03

[0382] G5 10 2.87

[0383] G6 12 -4.72

[0384] G7 14 -25.75

[0385] G8 16 4.77

[0386] G9 18 24.73

[0387] G10 20 -7.80

[0388] Numerical Example 4

[0389] Unit: mm

[0390] Surface data

[0391] Surface number rd nd νd Effective diameter

[0392] 1* 5.000 0.50 1.54400 56.0 5.88

[0393] 2* 2.227 0.34 4.24

[0394] 3* 2.344 0.40 1.69800 16.3 3.76

[0395] 4* 1.793 0.47 3.29

[0396] 5* 6.487 0.30 1.54400 56.0 3.07

[0397] 6* 4.232 0.19 2.76

[0398] 7* 1.969 0.30 1.62100 23.6 2.09

[0399] 8* 2.592 (variable) 1.75

[0400] 9 (aperture) ∞ 0.10 1.46

[0401] 10* -5.665 0.30 1.59100 27.2 1.35

[0402] 11* -2.538 0.08 1.47

[0403] 12* 89.117 0.83 1.54400 56.0 1.56

[0404] 13* -1.557 0.10 1.93

[0405] 14* -3.735 0.30 1.59100 27.2 1.97

[0406] 15* 6.169 0.34 2.34

[0407] 16* -5.072 0.35 1.69800 16.3 2.43

[0408] 17* -8.148 0.10 3.12

[0409] 18* 27.830 0.72 1.54400 56.0 4.01

[0410] 19* -2.347 0.16 4.39

[0411] 20* 2.820 0.87 1.54400 56.0 5.22

[0412] 21* 2.961 0.24 5.82

[0413] 22* 8.518 0.71 1.70500 14.0 6.28

[0414] 23* 4.126 0.38 7.13

[0415] 24 ∞ 0.26 1.51700 64.2 7.32

[0416] 25 ∞ (variable) 7.43

[0417] Image plane ∞

[0418] Aspherical surface data

[0419] First surface

[0420] K = 0.00000e+00, A4 = -6.07893e-04, A6 = 1.32175e-03, A8 = -2.93328e-04, A10 = 3.07045e-05, A12 = -1.25878e-06

[0421] Second surface

[0422] K = 0.00000e+00, A4 = 3.03485e-02, A6 = -1.67125e-02, A8 = 6.33996e-03, A10 = -1.07597e-03

[0423] Third Surface

[0424] K = 0.00000e+00, A4 = 9.16094e-02, A6 = -3.58801e-02, A8 = 1.03115e-02, A10 = -2.84761e-03, A12 = 2.39186e-04

[0425] Fourth surface

[0426] K = 0.00000e+00, A4 = 9.51787e-02, A6 = -2.90906e-02, A8 = -9.16503e-03, A10 = 1.21401e-03

[0427] Fifth Surface

[0428] K = 0.00000e+00, A4 = 1.12544e-01, A6 = -2.08590e-02, A8 = 8.45431e-04, A10 = -5.73030e-04

[0429] Sixth Surface

[0430] K = 0.00000e+00, A4 = 1.55899e-01, A6 = -5.98208e-02

[0431] Seventh Surface

[0432] K = 0.00000e+00, A4 = 6.97646e-02, A6 = -3.75828e-02

[0433] Eighth surface

[0434] K = 0.00000e+00, A4 = 5.97916e-02, A6 = 2.65502e-01, A8 = -6.09114e-01, A10 = 5.87441e-01

[0435] A18 = -5.15324e-01, A20 = 1.37029e-01

[0436] Tenth Surface

[0437] K = 0.00000e+00, A4 = -8.55150e-02, A6 = -1.28438e-01

[0438] Eleventh Surface

[0439] K = 0.00000e+00, A4 = 1.59565e-01, A6 = -6.60450e-01, A8 = 7.69393e-01, A10 = -3.08663e-01, A12 = 8.56686e-02, A14 = -3.97626e+00, A16 = 1.40912e+01

[0440] A18 = -1.89261e+01, A20 = 9.22077e+00

[0441] Twelfth Surface

[0442] K = 0.00000e+00, A4 = 3.35567e-01, A6 = -6.23402e-01, A8 = 3.12741e-01, A10 = 2.85469e+00, A12 = -1.11485e+01, A14 = 2.10627e+01, A16 = -2.22059e+01

[0443] A18 = 1.20228e+01, A20 = -2.44933e+00

[0444] Thirteenth Surface

[0445] K = 0.00000e+00, A4 = 1.44043e-02, A6 = -3.33594e-02

[0446] Fourteenth Surface

[0447] K = 0.00000e+00, A4 = -4.07482e-01, A6 = 1.58953e-01

[0448] The Fifteenth Surface

[0449] K = 0.00000e+00, A4 = -3.34168e-01, A6 = 6.35319e-03, A8 = 5.01334e-01, A10 = -1.43512e+00, A12 = 2.41307e+00, A14 = -2.48412e+00, A16 = 1.54198e+00

[0450] A18 = -5.33067e-01, A20 = 7.98230e-02

[0451] Sixteenth Surface

[0452] K = -1.26320e+01, A4 = 1.85302e-02, A6 = -1.69465e-01, A8 = 1.85576e-01, A10 = -3.88721e-01, A12 = 6.94163e-01, A14 = -7.92491e-01, A16 =5.32772e-01

[0453] A18 = -1.98749e-01, A20 = 3.05655e-02

[0454] The Seventeenth Surface

[0455] K = -1.00000e+00, A4 = -1.50198e-02, A6 = -5.99313e-03, A8 = -1.78373e-02, A10 = 3.19572e-02, A12 = -3.04820e-02, A14 = 1.52540e-02, A16 =-4.63191e-03

[0456] A18 = 9.11564e-04, A20 = -9.37171e-05

[0457] The Eighteenth Surface

[0458] K = 0.00000e+00, A4 = 4.50798e-02, A6 = -1.13848e-02

[0459] The Nineteenth Surface

[0460] K = 0.00000e+00, A4 = 6.75442e-02, A6 = 1.15663e-02, A8 = -7.29456e-03, A10 = 8.55124e-04

[0461] 20th Surface

[0462] K = 0.00000e+00, A4 = -6.04143e-02, A6 = 7.15022e-03, A8 = -5.74141e-04

[0463] Surface number twenty-one

[0464] K = 0.00000e+00, A4 = -5.00251e-02, A6 = 4.21282e-03, A8 = -3.31094e-04, A10 = 5.54193e-05, A12 = -6.88983e-06

[0465] Surface number twenty-two

[0466] A16 = 1.15953e-08

[0467] Surface number twenty-three

[0468] K = 0.00000e+00, A4 = -3.19763e-02, A6 = 4.61814e-03, A8 = -4.53528e-04, A10 = 1.92003e-05, A12 = 1.72738e-08, A14 = 4.58410e-10, A16 = -1.34101e-09

[0469] Various data

[0470] Focal length 2.58

[0471] F number 2.21

[0472] Half-angle view 56.35

[0473] Like the height of 3.88

[0474] Total lens length 9.00

[0475] BF 0.45

[0476] Lens unit data

[0477] unit initial surface focal length

[0478] L1 1 -6.13

[0479] L2 9 2.36

[0480] Single lens data

[0481] Lens starting surface focal length

[0482] G1 1 -7.88

[0483] G2 3 -15.55

[0484] G3 5 -23.47

[0485] G4 7 11.15

[0486] G5 10 7.51

[0487] G6 12 2.82

[0488] G7 14 -3.89

[0489] G8 16 -20.19

[0490] G9 18 4.01

[0491] G10 20 34.20

[0492] G11 22 -12.16

[0493] The values ​​of inequalities (1) to (8) in each example are indicated in Table 1.

[0494] Table 1

[0495]

[0496] Imaging equipment

[0497] Next, we will describe the imaging device using the optical system L0 in each example as the imaging optical system.

[0498] Figure 10 This is a schematic diagram of an imaging device 10 including the optical system L0 in each example. The imaging device 10 includes a camera body 13, an optical system 11 identical to one of the optical systems L0 described in Examples 1 to 4 above, and a light receiving element 12 that performs photoelectric conversion on the image formed by the optical system 11.

[0499] Note that an imaging element such as a CCD or CMOS sensor can be used as the light receiving element 12. In this case, the quality of the output image can be improved by using, for example, electrical methods to correct various aberrations (such as distortion aberration and chromatic aberration) in the image acquired by the light receiving element 12.

[0500] Note that the optical system L0 in each example is applicable not only to Figure 10 The digital still camera shown is also applicable to various types of optical devices such as digital video cameras and silver halide film cameras. Furthermore, the camera can be a lens-integrated type or a lens-interchangeable type.

[0501] Lens equipment

[0502] Next, the lens device using the optical system L0 of each example will be described.

[0503] Figure 11 This is a schematic external view of a lens device 20 including the optical systems L0 of various examples. The lens device 20 is a so-called interchangeable lens that is detachably mounted on a camera body (not shown).

[0504] Lens device 20 includes an imaging optical system 21 consisting of one of the optical systems described in Examples 1 to 4. Furthermore, lens device 20 includes a focus operation unit 22 and an operation unit 23 configured to change the imaging mode.

[0505] The focus operation unit 22 is operated by the user to mechanically or electrically change the arrangement of the imaging optical system 21, thereby changing the focus position.

[0506] Furthermore, the operation unit 23 can be operated by the user to change the arrangement of the lens elements of the imaging optical system 21 for purposes other than focusing. For example, in response to the operation of the operation unit 23, the arrangement of the lens elements of the imaging optical system 21 can be changed mechanically or electrically to alter the aberrations of the imaging optical system 21. In this case, in one embodiment, it is preferable that the focus position remains substantially unchanged.

[0507] While exemplary embodiments and examples of this disclosure have been described above, this disclosure is not limited to these embodiments and examples, and various combinations, variations and changes can be made within the scope of its spirit.

[0508] While this disclosure has been described with reference to embodiments, it should be understood that this disclosure is not limited to the disclosed embodiments. The scope of the following claims should be given the broadest interpretation to cover all such modifications and equivalent structures and functions.

Claims

1. A system comprising, from the object side to the image side: Front unit, the front unit having negative refractive power; Aperture stop; The rear unit, the rear unit having positive refractive power; and At least ten lenses, The rear unit includes an aspherical lens A with an inflection point, and The following inequalities are satisfied: -2.98 < f1 / f < 0.00 0.40 < ImgH / L Where f represents the focal length of the system as a whole, f1 represents the focal length of the front unit, ImgH represents the maximum image height of the system, and L represents the total length of the system.

2. The system according to claim 1, The following inequalities are satisfied: 0.52 < fG1 / f1 Where fG1 represents the focal length of the lens G1, which is the closest to the object among the lenses included in the front unit.

3. The system according to claim 1 or 2, The front unit includes a positive lens.

4. The system according to claim 1 or 2, in, In the rear unit, a positive lens, another positive lens, and a negative lens are sequentially arranged from the position closest to the object toward the image.

5. The system according to claim 1 or 2, The following inequalities are satisfied: -3.00 < fω1 / |f1| < 0.00 Where fω1 represents the off-axis focal length of the front element in the meridional direction.

6. The system according to claim 1 or 2, The following inequalities are satisfied: -6.00 < fGR / f2 < -2.00 Where fGR represents the focal length of the lens GR included in the rear unit and closest to the image setting, and f2 represents the focal length of the rear unit.

7. The system according to claim 1 or 2, The following inequalities are satisfied: 48.0 < ω < 70.0 Where ω[ ] represents the half-angle corresponding to the maximum image height of the system.

8. The system according to claim 1 or 2, The following inequalities are satisfied: 14.0 < νd < 40.0 Where νd represents the Abbe number of the material of the negative lens GN1, which is the closest negative lens to the object among the negative lenses included in the rear unit.

9. The system according to claim 8, The following inequalities are satisfied: 1.50 < nd < 1.70 Where nd represents the refractive index of the material of the negative lens GN1 relative to the d line.

10. The system according to claim 1, The following inequalities are satisfied: 0.40 < ImgH / L < 3.

00.

11. The system according to claim 1, The following inequalities are satisfied: 0.52 < fG1 / f1 < 2.00 Where fG1 represents the focal length of the lens G1, which is the closest to the object among the lenses included in the front unit.

12. The system according to claim 1 or 2, The system described includes a lens B made of resin material, and The object-side lens surface and the image-side lens surface of the lens B are at least one aspherical surface.

13. The system according to claim 1 or 2, This includes the object-side lens surface of the lens GR, located in the rear unit and closest to the image setting, comprising a convex portion near the axis on the object side and a concave peripheral portion on the object side. The image-side lens surface of the lens GR includes a concave portion near the axis and on the image side, and a convex peripheral portion on the image side.

14. The system according to claim 1 or 2, The object-side lens surface of lens GR1 includes a convex portion near the axis and a concave peripheral portion on the object side. Lens GR1 is disposed on the object side of the lens included in the rear unit and closest to the image placement lens, and is adjacent to the lens included in the rear unit and closest to the image placement lens. The image-side lens surface of the lens GR1 includes a concave portion near the axis and on the image side, and a convex peripheral portion on the image side.

15. The system according to claim 1 or 2, The object-side lens surface of the negative lens GN1, which is the closest negative lens to the object in the rear unit, includes a convex portion near the axis on the object side and a concave peripheral portion on the object side. The image-side lens surface of the negative lens GN1 includes a concave portion near the axis and on the image side, and a convex peripheral portion on the image side.

16. The system according to claim 1 or 2, The front unit consists of three lenses, and the rear unit consists of seven lenses.

17. The system according to claim 1 or 2, The front unit consists of four lenses, and the rear unit consists of seven lenses.

18. A system comprising, from the object side to the image side: Front unit, the front unit having negative refractive power; Aperture stop; The rear unit has a positive refractive force; as well as An aspherical lens, wherein the aspherical lens has an inflection point. The front unit includes at least three lenses, and The following inequalities are satisfied: -2.98 < f1 / f < 0.00 Where f represents the focal length of the system as a whole, and f1 represents the focal length of the front unit.

19. An imaging device, comprising: The system according to claim 1 or 2; as well as An imaging element that receives an image formed by the system.

20. A lens device, comprising: The system according to claim 1 or 2; as well as An operation unit configured to be operated by a user.

Images