Optical system, image pickup device, and lens device

Abstract

The invention provides an optical system, an imaging apparatus, and a lens apparatus. The system includes, in order from an object side to an image side, a front unit having a negative refractive power, an aperture stop, and a rear unit having a positive refractive power. The system includes at least eight lenses, the rear unit includes an aspherical lens (A) having an inflection point, and when a maximum image height of the system is represented by ImgH, an optical total length of the system is represented by L, a focal length of the front unit is represented by f1, and a focal length of a first lens (G1) included in the front unit and arranged closest to the object is represented by fG1, the system satisfies a predetermined inequality.

Description

Technical Field

[0001] The disclosure in this specification relates to systems suitable for digital still cameras, digital video cameras, surveillance cameras, airborne cameras, smartphone cameras, etc., devices including such systems, and lens devices including such systems. Background Technology

[0002] Wide-angle optical systems need to have high optical performance while being small in size. Japanese Patent Application 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] As one aspect of this disclosure, the system comprises, from the object side to the image side, a front unit with negative refractive power, an aperture stop, and a rear unit with positive refractive power, wherein the system includes at least eight lenses, the rear unit includes an aspherical lens A with an inflection point, and satisfies the following inequality:

[0004] 0.40 < ImgH / L

[0005] 0.52 < fG1 / f1

[0006] -2.98 < f1 / f < 0.00

[0007] 12.0 < νd < 40.0

[0008] Wherein, ImgH represents the maximum image height of the system, L represents the total optical length of the system, f1 represents the focal length of the front unit, fG1 represents the focal length of the first lens G1 included in the front unit and arranged closest to the object, f represents the focal length of the entire system, and νd represents the Abbe number of the material of the negative lens GN1 arranged closest to the object in the negative lens included in the rear unit.

[0009] The features of this disclosure will become apparent from the following description of embodiments with reference to the accompanying drawings. The following embodiments are described by way of example. Attached Figure Description

[0010] Figure 1 This is a cross-sectional view of the optical system in Example 1 during focusing at infinity.

[0011] Figure 2 This is the longitudinal aberration map corresponding to Example 1.

[0012] Figure 3 This is a cross-sectional view of the optical system in Example 2 during infinity focusing.

[0013] Figure 4This is the longitudinal aberration map corresponding to Example 2.

[0014] Figure 5 This is a cross-sectional view of the optical system in Example 3 during infinity focusing.

[0015] Figure 6 This is the longitudinal aberration map corresponding to Example 3.

[0016] Figure 7 This is a cross-sectional view of the optical system in Example 4 during infinity focusing.

[0017] Figure 8 This is the longitudinal aberration map corresponding to Example 4.

[0018] Figure 9 This is a schematic diagram related to the sagittal height of the first lens G1.

[0019] Figure 10 This is a schematic diagram relating to the point of impact of off-axis rays on an optical surface.

[0020] Figure 11 This is a schematic diagram of a camera device using one of the optical systems in Examples 1 to 4.

[0021] Figure 12 This is a schematic diagram of a lens assembly using one of the optical systems in Examples 1 to 4. Detailed Implementation

[0022] The embodiments disclosed in this 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.

[0023] Figure 1 , 3 Figures 5 and 7 are cross-sectional views of the optical systems L0 of Examples 1 to 4 during infinity focusing, respectively. The optical systems L0 of each example will be used in imaging devices such as digital still cameras, digital video cameras, surveillance cameras, and airborne cameras.

[0024] In the various cross-sectional views, the left side is the object side, and the right side is the image side. The optical systems L0 in each example include multiple lens units. Note that in this specification, a lens unit refers to a group of lenses isolated from each other by an aperture stop SP. Furthermore, each lens unit may include one lens or multiple lenses. Additionally, each lens unit may include aspherical lenses, Fresnel lenses, meta-lenses, diffractive optical elements, etc.

[0025] In the optical system L0 of each example, Li represents the i-th (i is a natural number) lens unit counted from the object side among the lens units included in the optical system L0. Additionally, Gk represents the k-th (k is a natural number) lens unit counted from the object side among the lens units included in the optical system.

[0026] In the optical systems L0 of each example, L1 (LF) represents the front unit of the lens unit arranged on the object side relative to the aperture stop. Similarly, L2 (LR) represents the rear unit of the lens unit arranged on the image side relative to the aperture stop.

[0027] In each cross-sectional view, SP stands for aperture stop. Furthermore, FL represents an optical element corresponding to an optical filter, low-pass filter, infrared cut-off filter, etc. IP stands for image plane, and when the optical system L0 in each example is used as the imaging optical system of a digital still camera or digital video camera, the imaging plane of a solid-state image sensing device, such as a CCD sensor or CMOS sensor, is disposed on the image plane IP. When the optical system L0 in 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 plane. Note that the optical systems in each example can be used as projection lenses for projectors, etc. In this case, the left side is the image side, and the right side is the projected image side.

[0028] Figure 2 , 4 Figures 6 and 8 are aberration diagrams of the optical systems L0 in Examples 1 to 4 during infinity focusing, respectively. In each diagram, from left to right, spherical aberration, astigmatic aberration, distortion aberration, and magnification chromatic aberration are indicated sequentially. In the spherical aberration diagram, Fno. is the F-value; 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 solid line indicates the amount of distortion aberration relative to the d-line. In the magnification chromatic aberration diagram, the double-dotted line indicates the chromatic aberration at the g-line. Furthermore, ω is the half-angle [°].

[0029] Figure 9 This is a cross-sectional view of the front unit L1 in the optical systems L0 of Examples 1 to 4. Figure 9 In the diagram, Ea indicates the effective diameter of the first lens G1, and Sag indicates the distance along the optical axis between the vertex of the face of the first lens G1 and the position of the effective diameter of the first lens G1.

[0030] Here, the off-axis focal lengths used in the various examples will be described. When the maximum half angle of view of an optical system L0 with an on-axis focal length of f0 is ω[°], the off-axis focal length is the focal length of an off-axis ray that enters at an angle ω[°] relative to the optical axis, passes through the center of the aperture stop SP, and forms an image on the image side.

[0031] Figure 10 A method for calculating off-axis focal length is shown. Figure 10 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.

[0032] exist Figure 10 In the diagram, the intersection point of the on-axis ray and the optical plane Gi is hp_0. Furthermore, the intersection point of the off-axis ray entering at the maximum angle ω [°] and the optical plane 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, the curvature varies depending on the azimuth angle. As described in Reference 1 below, the focal length of the off-axis principal ray can be obtained by calculating the curvature at the point of impact.

[0033] (Reference 1) Keisuke ARAKI, "Extension of Non-Co-Axial Optics into theImaging Systems" Japanese journal of optics, the Optical Society of Japan, June 2008, vol. 37, No. 6, p. 334 - 339

[0034] Next, the characteristic components of the optical system L0 for each example will be described.

[0035] 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. With the front unit L1 having negative refractive power, the optical system L0 has a so-called retrofocus type configuration, and the principal point is thus positioned on the image side, ensuring backfocus. Furthermore, the size of the optical system L0 can be reduced in the radial direction.

[0036] The optical systems L0 in each example include aspherical lenses. Furthermore, in the optical systems L0 of each example, at least one of the object-side and image-side lens surfaces of the aspherical lens (aspherical lens A) included in the rear unit L2 has an inflection point in its lens surface shape. An inflection point on the lens surface is a point where the sign of the lens's refractive power changes from a portion of the lens surface near the optical axis toward a peripheral portion of the lens surface. Including an aspherical lens with an inflection point allows for advantageous correction of field curvature and astigmatism aberrations.

[0037] 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 portion convex on the object side near the optical axis and a peripheral portion concave on the object side. Similarly, the image-side lens surface of the aspherical lens includes a portion concave on the image side near the optical axis and a peripheral portion convex on the image side. Therefore, Petzval correction can be performed on the portion of the aspherical lens near the optical axis while astigmatism correction is performed on the peripheral portion. Note that the object-side lens surface of the aspherical lens is not limited to this and may include a portion concave on the object side near the optical axis and a peripheral portion convex on the object side. Similarly, the image-side lens surface of the aspherical lens may include a portion concave on the image side near the optical axis and a peripheral portion convex on the image side.

[0038] Furthermore, the optical system L0 of each example is characterized by satisfying the following inequality (1), where ImgH represents the maximum image height of the optical system L0 and L represents its total optical length.

[0039] 0.40 < ImgH / L (1)

[0040] Inequality (1) defines the ratio between the maximum image height and the total optical length of the optical system L0. Here, the maximum image height of the optical system L0 refers to the distance from the position on the image plane IP where the peripheral illumination is 10% when the illumination is 100% on the optical axis to the optical axis. Furthermore, the total optical length L of the optical system L0 refers to the distance along the optical axis from the vertex of the object-side lens surface of the first lens G1 to the image plane, where the first lens G1 is included in the front unit L1 and is arranged closest to the object side. By satisfying inequality (1), the size of the optical system L0 can be reduced. When the ratio is less than the lower limit of inequality (1), the total length of the optical system L0 increases, which is not preferable due to the increased size of the optical system. Furthermore, in one embodiment, the upper limit of inequality (1) 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, thereby advantageously correcting various aberrations. Furthermore, in another embodiment, the upper limit of inequality (1) is set to 2.45, 2.40, 2.35, 2.30, 2.25, 2.20, 2.15, 2.10, 2.05, or 2.00.

[0041] The above-mentioned characteristics can be used to realize a small optical system L0 with high optical performance.

[0042] Next, the conditions that the optical system L0 in each example must satisfy will be described.

[0043] In one embodiment, when the focal length of the first lens G1, which is arranged closest to the object in the optical system L0, is represented by fG1, the following inequality (2) is satisfied.

[0044] 0.52 < fG1 / f1 (2)

[0045] Inequality (2) defines the focal length of the front unit L1 and the focal length of the first lens G1, wherein the first lens G1 is included in the front unit L1 and arranged closest to the object. By satisfying inequality (2), barrel distortion aberration generated in the optical system L0 can be advantageously corrected. Barrel distortion aberration is significantly generated when the individual focal lengths are less than the lower limit of inequality (2), which is not preferred. Furthermore, in one embodiment, the upper limit of inequality (2) 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 advantageously correct distortion aberration.

[0046] In one embodiment, when the focal length of the current unit L1 is represented by f1 and the focal length of the optical system L0 as a whole is represented by f, the following inequality (3) is satisfied.

[0047] -2.98 < f1 / f < 0.00 (3)

[0048] Inequality (3) defines the focal length of the front unit L1 relative to the focal length of the entire optical system L0. When the focal length of the front unit L1 is less than the lower limit of inequality (3), the absolute value of the negative refractive power of the front unit L1 decreases. In this case, in order to achieve both the correction of distortion aberrations and the correction of field curvature, the thickness deviation ratio of each lens constituting the front unit L1 will increase. Since the formability of the lens decreases, this is not preferred. When the focal length of the front unit L1 is greater than the upper limit of inequality (3), since the front unit L1 has positive refractive power, it is difficult to correct distortion aberrations and field curvature, which is also not preferred.

[0049] In one embodiment, when the off-axis focal length of the current unit L1 in the sagittal direction is represented by fω1, the following inequality (4) is satisfied.

[0050] 0.00 < fω1 / f1 < 3.00 (4)

[0051] Inequality (4) defines the ratio between the on-axis focal length and the off-axis focal length of the front unit L1. When the ratio is less than the lower limit of inequality (4), it is difficult to reduce the total length because the front unit L1 has positive refractive power for off-axis rays, which is not preferred. When the ratio is greater than the upper limit of inequality (4), it is difficult to correct barrel distortion aberration and field curvature because the front unit L1 has weaker refractive power for off-axis rays than for paraxial rays.

[0052] In one embodiment, when the focal length of the lens GR included in the rear unit L2 and arranged closest to the image is represented by fGR and the focal length of the rear unit L2 is represented by f2, the following inequality (5) is satisfied.

[0053] -6.00 < fGR / f2 < -2.00 (5)

[0054] Inequality (5) defines the range of the focal length of the lens GR. 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, leading to an increase in the total length of the optical system L0, which is not preferred. When the 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. Therefore, the back focal length of the optical system L0 decreases, causing the image plane IP and the lens GR to be too close to each other, which is not preferred.

[0055] In one embodiment, when the sagittal of the distance between the object-side vertex of the first lens G1 and the effective diameter position in the optical axis direction is represented by Sag and the effective diameter is represented by Ea, the following inequality (6) is satisfied. Here, with respect to the sagittal of the optical system L0, the direction toward the image side is considered the positive direction.

[0056] 0.00 < Sag / Ea < 0.25 (6)

[0057] Inequality (6) defines the range of distances along the optical axis between the vertex of the face of the first lens G1 and the effective diameter position. When the range is less than the lower limit of inequality (6), the distortion correction is insufficient because the peripheral portion of the object-side lens surface of the lens G1 has a concave surface on the object side, which is not preferred. When the range is greater than the upper limit of inequality (6), the curvature of the lens surface of the peripheral portion of the first lens G1 increases, resulting in a decrease in the formability of the first lens G1, which is also not preferred.

[0058] In one embodiment, when the half-angle of the optical system L0 is represented by ω, the following inequality (7) is satisfied.

[0059] 48.0 < ω < 70.0 (7)

[0060] Inequality (7) defines the range of the half-angle of the optical system L0. When the range is less than the lower limit of inequality (7), distortion aberrations and field curvature are overcorrected, which is not preferred. When the range is greater than the upper limit of inequality (7), distortion aberrations are not adequately corrected, which is also not preferred.

[0061] In one embodiment, when the material of the negative lens GN1, which is the closest to the object, is represented by νd with respect to the Abbe number of the d-line, the following inequality (8) is satisfied.

[0062] 12.0 < νd < 40.0 (8)

[0063] Inequality (8) defines the range of Abbe numbers for the material of the negative lens GN1.

[0064] When the range is less than the lower limit of inequality (8), the on-axis chromatic aberration is overcorrected, which is not preferred. When the range is greater than the upper limit of inequality (8), the on-axis chromatic aberration is not adequately corrected, which is also not preferred.

[0065] In another embodiment, when the refractive index of the material of the negative lens GN1, which is arranged closest to the image in the negative lens included in the rear unit L2, with respect to the d line is represented by nd, the following inequality (9) is satisfied.

[0066] 1.50 < nd < 1.80 (9)

[0067] Inequality (9) defines the range of the refractive index of the material of the negative lens GN1.

[0068] When the range is less than the lower limit of inequality (9), spherical aberration is not adequately corrected, which is not preferred. When the range is greater than the upper limit of inequality (9), spherical aberration is overcorrected, which is also not preferred.

[0069] In another embodiment, the numerical ranges in inequalities (1) to (9) are respectively set to the ranges in the following inequalities (1a) to (9a).

[0070] 0.41 < ImgH / L < 1.50 (1a)

[0071] 0.56 < fG1 / f1 (2a)

[0072] -2.80 < f1 / f < -1.00 (3a)

[0073] 0.50 < fω1 / f1 < 2.50 (4a)

[0074] -5.80 < fGR / f2 < -2.20 (5a)

[0075] 0.05 < Sag / Ea < 0.23 (6a)

[0076] 48.0 < ω < 70.0 (7a)

[0077] 15.0 < νd < 40.0 (8a)

[0078] 1.52 < nd < 1.75 (9a)

[0079] In addition, in another embodiment, the numerical ranges in inequalities (1) to (9) are respectively set to the ranges in the following inequalities (1b) to (9b).

[0080] 0.42 < 1 mgH / L < 1.30 (1b)

[0081] 0.60 < fG1 / f1 (2b)

[0082] -2.75 < f1 / f < -2.00 (3b)

[0083] 0.80 < fω1 / f1 < 2.20 (4b)

[0084] -5.50 < fGR / f2 < -2.80 (5b)

[0085] 0.10 < Sag / Ea < 0.20 (6b)

[0086] 50.0 < ω < 65.0 (7b)

[0087] 16.0 < νd < 35.0 (8a)

[0088] 1.55 < nd < 1.73 (9a)

[0089] Next, the configurations that the optical system L0 in each example must satisfy will be described.

[0090] The optical systems L0 in each example include at least eight lenses. The sensitivity of each lens can be increased by allowing the refractive power to be distributed among the lenses.

[0091] In the optical systems L0 of the various examples, the front unit L1 includes at least two lenses. Therefore, while ensuring the number of lenses to allow the optical system to have a wide angle, distortion aberrations in the front unit L1 can be advantageously corrected.

[0092] In the optical systems L0 of the various examples, the front unit L1 includes a positive lens. Since the rear unit L2 as a whole has positive refractive power, as a result of the positive lens being arranged in the front unit L1, lenses with positive refractive power are arranged on both the object side and image side of the aperture stop SP. Therefore, field curvature and distortion aberrations can be advantageously corrected.

[0093] 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 aspherical. Specifically, since the angle of incidence of off-axis rays entering the lens G1, which is arranged closest to the object in the front unit L1, is small, using an aspherical surface as the lens surface of lens G1 is advantageous for correcting distortion aberrations and ensuring peripheral illumination. In another embodiment, to enhance the above effects, both the object-side and image-side lens surfaces of lens G1 are aspherical.

[0094] In the optical system L0 of various examples, in one embodiment, a positive lens, other positive lenses, and a negative lens are arranged sequentially in the rear unit L2, starting from the position closest to the object. With the positive lenses positioned near and on the image side of the aperture stop SP, light rays that have already entered the rear unit L2 can be converged, and the distance from the aperture stop SP to the image plane can be reduced.

[0095] In one embodiment, the object-side lens surface of the lens GR, which is arranged closest to the image in the optical system L0 of each example, includes a portion convex on the object side near the optical axis and a peripheral portion concave on the object side. Similarly, the image-side lens surface of the lens GR includes a portion concave on the image side near the optical axis and a peripheral portion convex on the image side. Therefore, astigmatism at the peripheral portion can be corrected simultaneously with Petzval correction at the portion near the optical axis of the lens GR.

[0096] Furthermore, since an aspherical lens shape with inflection points such as those described above can be achieved, a resin lens (lens B) is used as the lens included in the optical system L0.

[0097] Next, the detailed configurations of Examples 1 to 4 will be described. Note that, regarding 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 described primarily.

[0098] Example 1

[0099] The optical system L0 of Example 1 comprises, 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. With the front unit L1 having negative refractive power, the optical system L0 has a so-called anti-focus configuration, and the principal point is thus positioned on the image side, allowing the size of the optical system L0 to be reduced in the radial direction while ensuring the back focal length.

[0100] In the optical system L0 of Example 1, the front unit L1 includes lenses G1 to G3, and the rear unit L2 includes lenses G4 to G9. Additionally, an optical filter FL may be arranged on the image side of the rear unit L2.

[0101] In the optical system L0 of Example 1, the object-side and image-side lens surfaces of the lens G1, which is arranged closest to the object in the front unit L1, each have aspherical shapes. Therefore, the incident angle of off-axis rays entering the lens G1 is small, which is beneficial for correcting distortion aberrations and ensuring peripheral illumination.

[0102] In the optical system L0 of Example 1, the positive lens, other positive lenses, and negative lenses are arranged sequentially in the rear unit L2, starting from the position closest to the object. Therefore, due to the positive refractive power near and in part of the image side of the aperture stop SP, 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.

[0103] In the optical system L0 of Example 1, the front unit L1 includes a positive lens G3. Therefore, lenses with positive refractive power are arranged on both the object side and the image side of the aperture stop SP, thus advantageously correcting field curvature and distortion aberrations.

[0104] In the optical system L0 of Example 1, the object-side lens surface of the lens GR, arranged closest to the image in the rear unit L2, includes a portion convex on the object side near the optical axis and a peripheral portion concave on the object side. Similarly, the image-side lens surface of the lens GR includes a portion concave on the image side near the optical axis and a peripheral portion convex on the image side. Therefore, Petzval aberrations at the portion near the optical axis of the lens GR can be corrected simultaneously with astigmatism at the peripheral portion. Furthermore, the negative lens GN1, arranged closest to the object in the negative lens of the rear unit L2, also has a lens shape similar to that of the lens GR.

[0105] In the optical system L0 of Example 1, the negative lens GN1, arranged closest to the object in the rear unit L2, is a lens made of resin material. Therefore, the formability of the negative lens GN1 is improved, and it can be formed into a negative lens GN1 with an aspherical lens shape having an inflection point.

[0106] Example 2

[0107] In the optical system L0 of Example 2, the front unit L1 includes lenses G1 and G2, and the rear unit L2 includes lenses G3 to G8. Additionally, an optical filter FL can be arranged on the image side of the rear unit L2. With eight lenses, the total optical length of the optical system L0 is reduced, and the size of the optical system L0 can be decreased.

[0108] In the optical system L0 of Example 2, the front unit L1 includes a positive lens G2. Therefore, lenses with positive refractive power are arranged on both the object side and the image side of the aperture stop SP, thus advantageously correcting field curvature and distortion aberrations.

[0109] Example 3

[0110] In the optical system L0 of Example 3, the front unit L1 includes lenses G1 to G3, and the rear unit L2 includes lenses G4 to G10. When the optical system L0 includes ten lenses, the sensitivity of each lens can be increased by allowing the refractive power to be distributed among the lenses.

[0111] Example 4

[0112] In the optical system L0 of Example 4, the front unit L1 includes lenses G1 to G4, and the rear unit L2 includes lenses G5 to G11. Additionally, an optical filter FL can be arranged on the image side of the rear unit L2. When the optical system L0 includes eleven lenses, the sensitivity of each lens can be increased by allowing the refractive power to be distributed among the lenses.

[0113] In the optical system L0 of Example 4, three negative lenses are arranged sequentially 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, in one embodiment, a strong negative refractive power is required on the object side of the optical system. By allowing the negative refractive power to be shared among the three negative lenses, the refractive power of each negative lens can be reduced. Therefore, barrel distortion aberration and field curvature can be suppressed.

[0114] The numerical examples 1 to 4 corresponding to examples 1 to 4 are shown below.

[0115] 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 between the k-th and (k+1)-th surfaces along the optical axis. Note that k is the surface number counted from the object side. Furthermore, nd represents the refractive index of each optical component with respect to the d-line, and νd represents the Abbe number 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 formula.

[0116] νd = (nd - 1) / (nF - nC)

[0117] Note that in each numerical example, the half-angle (°) of the optical system is indicated, and the maximum image height corresponding to the half-angle is indicated as "image height". Furthermore, in each numerical example, the focal length of each lens unit at line d is indicated as lens unit data. Note that d, focal length [mm], F-number, and half-angle [°] are values ​​when the optical system in each example is 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 to a value in air. "Total lens length" is the length obtained by adding the back focal length to the distance along the optical axis from the frontmost lens surface (the surface closest to the object) to the rearmost lens surface of the optical system.

[0118] In addition, symbols The aspherical shape is represented by the following expression, where X represents the displacement from the vertex of the face in the direction of the optical axis, h represents the height from the optical axis in the direction perpendicular to the optical axis, R represents the paraxial radius of curvature, k represents the conic constant, and A4, A6, A8, A10, A12, A14, A16, A18, and A20 each represent the aspherical coefficients of each order.

[0119] X = (h 2 / R) / [1 + {1 - (1 + k)(h / R)2}] 1 / 2 + A4 × h 4 + A6 × h 6 + A8 × h 8 + A10 × h 10 + A12 × h 12 + A14 × h 14 + A16 × h 16 + A18 × h 18 + A20 × h 20

[0120] In the various aspherical coefficients, "e±XX" represents "×10±". XX ".

[0121] Numerical Example 1

[0122] Unit: mm

[0123] Surface data

[0124]

[0125] Image plane ∞

[0126] Spherical data

[0127] First page

[0128] K = 0.00000e+00, A4 = 2.54970e-02, A6 = -6.40902e-04, A8 = -4.27401e-03, A10 = 1.50107e-03, A12 = -1.58449e-04

[0129] Second side

[0130] K = 0.00000e+00, A4 = 6.33958e-02, A6 = -7.37338e-02, A8 = 1.68063e-02, A10 = -2.07051e-03

[0131] Third side

[0132] K = 0.00000e+00, A4 = 3.77375e-02, A6 = -1.67398e-01, A8 = 1.74110e-01, A10 = -7.73265e-02, A12 = 1.12872e-02

[0133] Fourth page

[0134] K = 0.00000e+00, A4 = -6.13897e-02, A6 = -3.88994e-01, A8 = 5.79202e-01, A10 = -3.12293e-01

[0135] Fifth page

[0136] K = 0.00000e+00, A4 = -5.70688e-02, A6 = -2.95821e-01

[0137] Sixth page

[0138] K = 0.00000e+00, A4 = 9.60136e-02, A6 = -6.18947e-02, A8 = -5.95627e-01, A10 = 6.65492e-01

[0139] A18 = -5.15324e-01, A20 = 1.37029e-01

[0140] Eighth page

[0141] K = 0.00000e+00, A4 = -1.23212e-01, A6 = -4.76965e-03

[0142] Ninth page

[0143] K = 0.00000e+00, A4 = 4.16656e-02, A6 = -4.78646e-01, A8 = -2.02302e-01, A10 = 1.76310e+01, A12 = -1.08531e+02, A14 = 3.42880e+02, A16 = -6.16495e+02

[0144] A18 = 5.98947e+02, A20 = -2.44370e+02

[0145] Eleventh page

[0146] K = 0.00000e+00, A4 = 1.47619e-01, A6 = -7.54190e-01, A8 = 2.62330e+00, A10 = -6.06508e+00, A12 = 8.07422e+00, A14 = -4.81606e+00, A16 = -9.74318e-01

[0147] A18 = 2.62662e+00, A20 = -8.39803e-01

[0148] Page Twelve

[0149] K = 0.00000e+00, A4 = 5.09820e-02, A6 = -1.78266e-02

[0150] Page Thirteen

[0151] K = 0.00000e+00, A4 = -1.80286e-01, A6 = 4.80067e-02

[0152] Page Fourteen

[0153] K = 0.00000e+00, A4 = -1.78921e-01, A6 = -1.21046e-01, A8 = 5.69246e-01, A10 = -1.53447e+00, A12 = 2.53863e+00, A14 = -2.73111e+00, A16 = 1.80510e+00

[0154] A18 = -6.50599e-01, A20 = 9.73099e-02

[0155] Page 15

[0156] A16 = 3.38996e+00

[0157] A18 = -1.32669e+00, A20 = 2.09991e-01

[0158] Page 16

[0159] K = -1.00000e+00, A4 = -3.02303e-01, A6 = 4.25798e-01, A8 = -5.97774e-01, A10 = 7.34558e-01, A12 = -6.19998e-01, A14 = 3.17882e-01, A16 =-9.02908e-02

[0160] A18 = 1.19372e-02, A20 = -3.39726e-04

[0161] Page 17

[0162] K = 0.00000e+00, A4 = 2.19111e-01, A6 = -6.65840e-02

[0163] Page 18

[0164] K = 0.00000e+00, A4 = 1.22189e-01, A6 = -1.86431e-02, A8 = 2.18119e-03, A10 = 3.38466e-05

[0165] Page 19

[0166] K = 0.00000e+00, A4 = -1.61286e-01, A6 = 1.54522e-02, A8 = -6.00885e-03

[0167] Page 20

[0168] K = 0.00000e+00, A4 = -7.36344e-02, A6 = 7.74757e-03, A8 = -1.27965e-03, A10 = 1.28730e-04, A12 = -1.17664e-05

[0169] Various data

[0170] Focal length 2.94

[0171] F-value 2.21

[0172] Angle of view 52.79

[0173] Like the height of 3.88

[0174] Total lens length: 7.13

[0175] BF 1.52

[0176] Lens-Unit Data

[0177] unit start surface focal length

[0178] L1 1 -6.65

[0179] L2 7 2.33

[0180] Single lens data

[0181]

[0182] Numerical Example 2

[0183] Unit: mm

[0184] Surface data

[0185]

[0186] Image plane ∞

[0187] Spherical data

[0188] First page

[0189] K = -1.09449e+01, A4 = 4.21461e-02, A6 = -1.02324e-02, A8 = 4.89806e-03, A10 = -1.63399e-03, A12 = 3.39007e-04, A14 = -3.57982e-05, A16 =9.91744e-07

[0190] A18 = -8.66980e-08, A20 = 1.61150e-09

[0191] Second side

[0192] K = -4.77071e+00, A4 = 3.86428e-01, A6 = -5.68268e-01, A8 = 1.27418e+00, A10 = -2.12005e+00, A12 = 2.29734e+00, A14 = -1.48840e+00, A16 =5.06978e-01

[0193] A18 = -6.55830e-02, A20 = -1.99040e-03

[0194] Third side

[0195] K = 0.00000e+00, A4 = 7.09504e-02, A6 = 2.20062e-01, A8 = -3.07588e-01, A10 = 4.31630e-01, A12 = -1.24465e+00, A14 = 1.42501e+00, A16 = -3.31675e-01

[0196] A18 = -2.81020e-01, A20 = 4.67600e-02

[0197] Fourth page

[0198] K = 2.25764e+01, A4 = 1.85210e-01, A6 = 9.82566e-01, A8 = -5.30993e+00, A10 = 2.24078e+01, A12 = -5.72662e+01, A14 = 7.39959e+01, A16 = -2.94485e+01

[0199] A18 = -2.28850e+01, A20 = 9.50830e+00

[0200] Sixth page

[0201] K = 0.00000e+00, A4 = 5.77219e-02, A6 = 2.95467e-02, A8 = -1.81855e+00, A10 = 1.58735e+00, A12 = 1.08936e+02, A14 = -8.82560e+02, A16 = 3.01080e+03

[0202] A18 = -4.90080e+03, A20 = 3.11340e+03

[0203] Seventh page

[0204] K = 0.00000e+00, A4 = -1.35288e-01, A6 = 5.51389e-01, A8 = -6.52425e+00, A10 = 4.50622e+01, A12 = -1.94162e+02, A14 = 5.16831e+02, A16 = -8.29792e+02

[0205] A18 = 7.34640e+02, A20 = -2.75210e+02

[0206] Eighth page

[0207] K = 0.00000e+00, A4 = -6.02118e-02, A6 = 7.63129e-01, A8 = -5.14082e+00, A10 = 2.51467e+01, A12 = -7.57406e+01, A14 = 1.40016e+02, A16 = -1.46692e+02

[0208] A18 = 6.84050e+01, A20 = -2.68246e+00

[0209] Ninth page

[0210] K = 2.12397e+00, A4 = 6.57713e-02, A6 = -2.03053e+00, A8 = 8.36111e+00, A10 = -2.35565e+01, A12 = 4.52377e+01, A14 = -5.63275e+01, A16 = 4.36473e+01

[0211] A18 = -1.89155e+01, A20 = 3.49253e+00

[0212] Page 10

[0213] K = -1.77841e+01, A4 = 2.88919e-01, A6 = -2.73548e+00, A8 = 7.86385e+00, A10 = -1.63038e+01, A12 = 2.51925e+01, A14 = -3.31230e+01, A16 = 3.67650e+01

[0214] A18 = -2.72793e+01, A20 = 8.00798e+00

[0215] Eleventh page

[0216] A16 = 2.23548e+00

[0217] A18 = -5.39182e-01, A20 = 6.30107e-02

[0218] Page Twelve

[0219] K = -5.85659e+00, A4 = -9.43399e-02, A6 = -3.67868e-01, A8 = 1.10109e+00, A10 = -1.44062e+00, A12 = 1.11738e+00, A14 = -5.50431e-01, A16 =1.70838e-01

[0220] A18 = -3.05712e-02, A20 = 2.37267e-03

[0221] Page Thirteen

[0222] K = 0.00000e+00, A4 = -5.31965e-03, A6 = 7.84844e-04, A8 = -1.36639e-03

[0223] Page Fourteen

[0224] K = 0.00000e+00, A4 = -3.58813e-03, A6 = 1.12176e-03, A8 = -2.20043e-04, A10 = 3.94519e-05

[0225] Page 15

[0226] K = 0.00000e+00, A4 = 3.47171e-03, A6 = 1.99077e-02, A8 = -3.06640e-01, A10 = 5.02628e-01, A12 = -3.64013e-01, A14 = 1.38631e-01, A16 = -2.74899e-02

[0227] A18 = 2.35659e-03, A20 = -3.02755e-05

[0228] Page 16

[0229] K = 0.00000e+00, A4 = -1.19473e-01, A6 = 1.04106e-01, A8 = -6.02809e-01, A10 = 9.19869e-01, A12 = -6.71299e-01, A14 = 2.74179e-01, A16 = -6.43304e-02

[0230] A18 = 8.13327e-03, A20 = -4.31857e-04

[0231] Page 17

[0232] K = 0.00000e+00, A4 = -2.80744e-02, A6 = -1.62828e-01, A8 = 1.45446e-01, A10 = -6.32545e-02, A12 = 1.63531e-02, A14 = -2.64957e-03, A16 =2.65366e-04

[0233] A18 = -1.50195e-05, A20 = 3.63367e-07

[0234] Various data

[0235] Focal length 1.92

[0236] F-value 2.21

[0237] Perspective 58.21

[0238] Like the height 3.10

[0239] Total lens length 6.50

[0240] BF 0.41

[0241] Lens-Unit Data

[0242] unit start surface focal length

[0243] L1 1 -3.11

[0244] L2 6 1.71

[0245] Single lens data

[0246]

[0247] Numerical Example 3

[0248] Unit: mm

[0249] Surface data

[0250]

[0251] Image plane ∞

[0252] Spherical data

[0253] First page

[0254] K = 0.00000e+00, A4 = -3.07731e-03, A6 = 3.00737e-03, A8 = -8.47144e-04, A10 = 1.21092e-04, A12 = -6.93945e-06

[0255] Second side

[0256] K = 0.00000e+00, A4 = 2.86153e-02, A6 = -3.02061e-02, A8 = 9.25596e-03, A10 = -1.37869e-03

[0257] Third side

[0258] K = 0.00000e+00, A4 = 6.15659e-02, A6 = -4.70842e-02, A8 = 1.50910e-02, A10 = -2.32884e-03, A12 = 2.32308e-05

[0259] Fourth page

[0260] K = 0.00000e+00, A4 = 3.86307e-02, A6 = -4.60362e-02, A8 = 1.68308e-02, A10 = -4.98505e-03

[0261] Fifth page

[0262] K = 0.00000e+00, A4 = 3.66836e-02, A6 = 2.61744e-02

[0263] Sixth page

[0264] K = 0.00000e+00, A4 = 8.63360e-02, A6 = 1.36372e-01, A8 = -2.19196e-01, A10 = 2.29418e-01

[0265] A18 = -5.15324e-01, A20 = 1.37029e-01

[0266] Eighth page

[0267] K = 0.00000e+00, A4 = -1.03223e-01, A6 = -9.83741e-02

[0268] Ninth page

[0269] 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

[0270] A18 = 7.18831e+01, A20 = -2.41209e+01

[0271] Page 10

[0272] 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

[0273] A18 = 1.40973e+01, A20 = -3.29067e+00

[0274] Eleventh page

[0275] K = 0.00000e+00, A4 = 3.16674e-02, A6 = -3.34507e-02

[0276] Page Twelve

[0277] K = 0.00000e+00, A4 = -3.06293e-01, A6 = 1.14326e-01

[0278] Page Thirteen

[0279] 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

[0280] A18 = -4.73228e-01, A20 = 6.95500e-02

[0281] Page Fourteen

[0282] 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

[0283] A18 = -1.75866e-01, A20 = 2.96999e-02

[0284] Page 15

[0285] 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

[0286] A18 = 3.04576e-04, A20 = -5.54668e-06

[0287] Page 16

[0288] K = 0.00000e+00, A4 = 6.26857e-02, A6 = -1.40260e-02

[0289] Page 17

[0290] K = 0.00000e+00, A4 = 6.95417e-02, A6 = 1.29310e-02, A8 = -8.04863e-03, A10 = 9.39637e-04

[0291] Page 18

[0292] K = 0.00000e+00, A4 = -5.92072e-02, A6 = 4.64173e-03, A8 = -3.64040e-04

[0293] Page 19

[0294] K = 0.00000e+00, A4 = -3.98586e-02, A6 = 3.65251e-03, A8 = -4.07558e-04, A10 = 3.33785e-05, A12 = -2.86780e-06

[0295] Page 20

[0296] 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

[0297] Page 21

[0298] 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

[0299] Various data

[0300] Focal length 3.02

[0301] F-value 2.21

[0302] Perspective 52.06

[0303] Like the height of 3.88

[0304] Total lens length: 8.70 mm

[0305] BF 0.45

[0306] Lens-Unit Data

[0307]

[0308] Single lens data

[0309]

[0310] Numerical Example 4

[0311] Unit: mm

[0312] Surface data

[0313]

[0314] Image plane ∞

[0315] Spherical data

[0316] First page

[0317] K = 0.00000e+00, A4 = -6.07893e-04, A6 = 1.32175e-03, A8 = -2.93328e-04, A10 = 3.07045e-05, A12 = -1.25878e-06

[0318] Second side

[0319] K = 0.00000e+00, A4 = 3.03485e-02, A6 = -1.67125e-02, A8 = 6.33996e-03, A10 = -1.07597e-03

[0320] Third side

[0321] K = 0.00000e+00, A4 = 9.16094e-02, A6 = -3.58801e-02, A8 = 1.03115e-02, A10 = -2.84761e-03, A12 = 2.39186e-04

[0322] Fourth page

[0323] K = 0.00000e+00, A4 = 9.51787e-02, A6 = -2.90906e-02, A8 = -9.16503e-03, A10 = 1.21401e-03

[0324] Fifth page

[0325] K = 0.00000e+00, A4 = 1.12544e-01, A6 = -2.08590e-02, A8 = 8.45431e-04, A10 = -5.73030e-04

[0326] Sixth page

[0327] K = 0.00000e+00, A4 = 1.55899e-01, A6 = -5.98208e-02

[0328] Seventh page

[0329] K = 0.00000e+00, A4 = 6.97646e-02, A6 = -3.75828e-02

[0330] Eighth page

[0331] K = 0.00000e+00, A4 = 5.97916e-02, A6 = 2.65502e-01, A8 = -6.09114e-01, A10 = 5.87441e-01

[0332] A18 = -5.15324e-01, A20 = 1.37029e-01

[0333] Page 10

[0334] K = 0.00000e+00, A4 = -8.55150e-02, A6 = -1.28438e-01

[0335] Eleventh page

[0336] 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

[0337] A18 = -1.89261e+01, A20 = 9.22077e+00

[0338] Page Twelve

[0339] 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

[0340] A18 = 1.20228e+01, A20 = -2.44933e+00

[0341] Page Thirteen

[0342] K = 0.00000e+00, A4 = 1.44043e-02, A6 = -3.33594e-02

[0343] Page Fourteen

[0344] K = 0.00000e+00, A4 = -4.07482e-01, A6 = 1.58953e-01

[0345] Page 15

[0346] 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

[0347] A18=-5.33067e-01, A20=7.98230e-02

[0348] Page 16

[0349] 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

[0350] A18 = -1.98749e-01, A20 = 3.05655e-02

[0351] Page 17

[0352] 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

[0353] A18 = 9.11564e-04, A20 = -9.37171e-05

[0354] Page 18

[0355] K = 0.00000e+00, A4 = 4.50798e-02, A6 = -1.13848e-02

[0356] Page 19

[0357] K = 0.00000e+00, A4 = 6.75442e-02, A6 = 1.15663e-02, A8 = -7.29456e-03, A10 = 8.55124e-04

[0358] Page 20

[0359] K = 0.00000e+00, A4 = -6.04143e-02, A6 = 7.15022e-03, A8 = -5.74141e-04

[0360] Page 21

[0361] K = 0.00000e+00, A4 = -5.00251e-02, A6 = 4.21282e-03, A8 = -3.31094e-04, A10 = 5.54193e-05, A12 = -6.88983e-06

[0362] Page 22

[0363] A16 = 1.15953e-08

[0364] Page 23

[0365] 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

[0366] Various data

[0367] Focal length 2.58

[0368] F-value 2.21

[0369] Angle of view 56.35

[0370] Like the height of 3.88

[0371] Total lens length 9.00

[0372] BF 0.45

[0373] Lens-Unit Data

[0374] unit start surface focal length

[0375] L1 1 -6.13

[0376] L2 9 2.36

[0377] Single lens data

[0378]

[0379] Table 1 shows the values ​​under inequalities (1) to (9) in each example.

[0380] Table 1

[0381]

[0382] camera device

[0383] Next, the optical system L0 in each example will be described as the camera device used as a camera optical system.

[0384] Figure 11 This is a schematic diagram of a camera device 10 including the optical system L0 in each example. The camera 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.

[0385] 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.

[0386] Note that this applies not only to Figure 11 The digital still camera shown, and the optical system L0 of each example, are also applicable to various types of optical devices such as digital video cameras and silver halide film cameras. Furthermore, the camera can be of the lens-integrated type or the lens-interchangeable type.

[0387] Lens device

[0388] Next, the lens arrangement using the optical system L0 of each example will be described.

[0389] Figure 12 This is a schematic external view of a lens assembly 20 including the optical systems L0 of the various examples. The lens assembly 20 is a so-called interchangeable lens detachably mounted on a camera body (not shown). The lens assembly 20 includes a camera optical system 21 formed by one of the optical systems described in Examples 1 to 4. In addition, the lens assembly 20 includes a focusing operation unit 22 and an operation unit 23 configured to change the shooting mode.

[0390] The focusing operation unit 22 is operated by the user to mechanically or electrically change the configuration of the camera optical system 21, so that the focus position can be changed.

[0391] Additionally, the operation unit 23 can be operated by the user to change the configuration of the lens units of the imaging optical system 21 for purposes other than focusing. For example, in response to the operation of the operation unit 23, the configuration of the lens units 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, the focus position remains substantially unchanged.

[0392] 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 its spirit.

[0393] 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 appended claims should be given the broadest interpretation to cover all such modifications and equivalent structures and functions.

Claims

1. An optical system comprising, from the object side to the image side: The anterior unit has negative refractive power; Aperture stop; as well as The rear unit has positive refractive power. The optical system includes at least eight lenses. The rear unit includes an aspherical lens A with an inflection point, and Among them, the following inequalities are satisfied: 0.40 < 1 mgH / L 0.52 < fG1 / f1, -2.98 < f1 / f < 0.00, 12.0 < νd < 40.0, Wherein, ImgH represents the maximum image height of the optical system, L represents the total optical length of the optical system, f1 represents the focal length of the front unit, fG1 represents the focal length of the first lens G1 included in the front unit and arranged closest to the object, f represents the focal length of the entire optical system, and νd represents the Abbe number of the material of the negative lens GN1, which is arranged closest to the object in the negative lens included in the rear unit.

2. The optical system according to claim 1, in, In the rear unit, positive lenses, other positive lenses, and negative lenses are arranged sequentially from the position closest to the object toward the image.

3. The optical system according to claim 1, in, The following inequalities must be satisfied: 0.00 < fω1 / f1 < 3.00, Where fω1 represents the off-axis focal length of the front unit in the sagittal direction.

4. The optical system according to claim 1, in, The following inequalities must be satisfied: -6.00 < fGR / f2 < -2.00, Wherein, fGR represents the focal length of the lens GR included in the rear unit and arranged closest to the image, and f2 represents the focal length of the rear unit.

5. The optical system according to claim 1, in, The optical system includes a lens B made of resin material, and Wherein, at least one of the object-side lens surface and the image-side lens surface of the lens B is an aspherical surface.

6. The optical system according to claim 1, in, The following inequalities must be satisfied: 0.00 < Sag / Ea < 0.25 Wherein, Sag represents the axial distance between the vertex of the object-side lens surface of the first lens G1 and the effective diameter position, and Ea represents the effective diameter of the first lens G1.

7. The optical system according to claim 1, in, The following inequalities must be satisfied: 48.0 < ω < 70.0 Where ω[°] represents the half angle corresponding to the maximum image height of the optical system.

8. The optical system according to claim 1, in, The following inequalities must be satisfied: 1.50 < nd < 1.70, Wherein, nd represents the refractive index of the material of the negative lens GN1 with respect to the d-line.

9. The optical system according to claim 1, in, The following inequalities must be satisfied: 0.40 < ImgH / L ≤ 3.

00.

10. The optical system according to claim 1, in, The following inequalities must be satisfied: 0.52 < fG1 / f1 ≤ 2.

00.

11. The optical system according to claim 1, in, The object-side lens surface of the negative lens GN1 includes a portion protruding on the object side near the axis and a peripheral portion recessed on the object side, and The image-side lens surface of the negative lens GN1 includes a portion located near the axis and recessed on the image side, and a peripheral portion protruding on the image side.

12. The optical system according to claim 1, in, The object-side lens surface of the lens GR, which is included in the rear unit and is closest to the image arrangement, includes a portion protruding on the object side near the axis and a peripheral portion recessed on the object side. The image-side lens surface of the lens GR includes a portion located near the axis and recessed on the image side, and a peripheral portion protruding on the image side.

13. The optical system according to claim 1, in, The front unit includes two lenses, and the rear unit includes six lenses.

14. The optical system according to claim 1, in, The front unit includes three lenses, and the rear unit includes six lenses.

15. The optical system according to claim 1, in, The front unit includes three lenses, and the rear unit includes seven lenses.

16. The optical system according to claim 1, in, The front unit includes four lenses, and the rear unit includes seven lenses.

17. An optical system comprising, from the object side to the image side: The anterior unit has negative refractive power; Aperture stop; as well as The rear unit has positive refractive power. The front unit includes at least two lenses. The rear unit includes an aspherical lens with an inflection point, and Among them, the following inequalities are satisfied: 0.40 < 1 mgH / L Where ImgH represents the maximum image height of the optical system, and L represents the total optical length of the optical system.

18. A camera device, comprising: The optical system according to any one of claims 1 to 17; as well as A camera element that receives the image formed by the optical system.

19. A lens device, comprising: The optical system according to any one of claims 1 to 17; as well as An operating unit that is configured to be operated by a user.

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