Optical system and imaging device

Abstract

The optical system includes a first aperture having a variable aperture diameter, three or more lenses including a positive lens and a negative lens disposed closer to the object side than the first aperture, and a second aperture having a fixed aperture diameter, and the distance on the optical axis from the first aperture to the second aperture is Dst and the focal length of the optical system is f. The optical system satisfies the conditional expression represented by 0.005 < Dst / f < 2.

Description

Technical Field

[0001] The technology of the present invention relates to an optical system and an imaging device. Background Art

[0002] In the past, there are known optical systems that are provided with a stopper or an aperture in addition to an aperture for determining an F value. For example, Japanese Patent Laid-Open No. 07-209571 describes an optical system having the following structure: in addition to an aperture stop for determining an F value, a focus lens group that moves during a focusing operation is provided with a glare blocker, and the opening diameter of the glare blocker changes during focusing. Japanese Patent Laid-Open No. 07-209570 describes an optical system having the following structure: a focus lens group that moves during a focusing operation is provided with a glare blocker, and the glare stopper moves independently of the movement of the focus lens group during focusing.

[0003] Japanese Patent Application Laid-Open No. 2011-107312 describes the following structure: in a zoom lens having a first lens group, a second lens group, and a third lens group in order from the object side to the image side, a sub-aperture is arranged on the image side of the second lens group. Japanese Patent Application Laid-Open No. 2016-191766 describes a zoom lens having a first lens group, a second lens group, a third lens group, and a rear lens group from the object side, and having a flare-cut aperture and an Fno aperture between the second group and the third group.

[0004] Japanese Patent Publication No. 2002-023050 describes the following structure: in a photographic lens including a first lens and a second lens in order from the object side, the aperture position is set to the image side of the second lens, and a glare blocker for limiting the optical path of off-axis light is provided between the first lens and the second lens. Japanese Patent Publication No. 2019-049645 describes a zoom lens including an aperture stop for determining (limiting) an open F value of a light beam and a glare cutter. Summary of the invention

[0005] The present invention provides an optical system which can achieve miniaturization, suppress the decrease of light quantity in the peripheral part of an image, and improve the imaging performance at the intermediate image height, and an imaging device having the optical system.

[0006] Means for solving technical problems

[0007] An optical system according to one embodiment of the present invention comprises: a first aperture having a variable aperture diameter; three or more lenses including a positive lens and a negative lens arranged on the object side of the first aperture; and a second aperture having a fixed aperture diameter, wherein when the distance on the optical axis from the first aperture to the second aperture is set to Dst, the focal length of the optical system is set to f, and when the optical system is a variable magnification optical system, Dst and f are set to values ​​in a variable magnification state in which the height of an on-axis marginal ray from the optical axis reaches a maximum at the position of the second aperture,

[0008] The above optical system satisfies the conditional equation (1) represented by the following equation:

[0009] 0.005<|Dst| / f<2 (1).

[0010] When the opening diameter of the first aperture in the open state is set to φF, the opening diameter of the second aperture is set to φS, and when the optical system is a variable-power optical system, φF and φS are set to values ​​in the variable-power state where the height of the on-axis marginal light from the optical axis at the position of the second aperture reaches the maximum, the optical system of the above-mentioned method preferably satisfies conditional expression (2) represented by the following expression:

[0011] 0.3<φS / φF<2.5 (2).

[0012] In a structure in which a convex lens surface in contact with air is located in the opening of the second aperture, when the distance on the optical axis from the intersection of the lens surface and the optical axis to the second aperture in which the lens surface is located in the opening is set to Dp, with respect to Dp, the sign of the distance on the image side is set to positive, the sign of the distance on the object side is set to negative, and the paraxial curvature radius of the lens surface is set to Rp, the optical system of the above-mentioned mode preferably satisfies conditional formula (3) represented by the following formula:

[0013] 0<Dp / Rp<0.4 (3).

[0014] In a structure in which a convex lens surface in contact with air is located in the opening of the second aperture, when the distance on the optical axis from the intersection of the lens surface and the optical axis to the second aperture in which the lens surface is located in the opening is set to Dp, with respect to Dp, the sign of the distance on the image side is set to positive, the sign of the distance on the object side is set to negative, the paraxial curvature radius of the lens surface is set to Rp, and the effective diameter of the lens surface is set to φEp, the optical system of the above-mentioned mode preferably satisfies conditional formula (4) represented by the following formula:

[0015] 0.7<{Rp-Rp×(1-(φEp / 2) 2 / Rp 2 ) 1 / 2} / Dp<1.5 (4).

[0016] In a structure in which a concave lens surface in contact with air is located near the second aperture, the distance on the optical axis from the intersection of the lens surface and the optical axis to the second aperture is set to Dn, with respect to Dn, the sign of the distance on the image side is set to positive, and the sign of the distance on the object side is set to negative, with the intersection as a reference, and the paraxial curvature radius of the lens surface is set to Rn, when there are two concave lens surfaces in contact with air located near the second aperture, the value of the lens surface having a diameter of the optically effective surface closer to the aperture diameter of the second aperture of the two lens surfaces is used for Dn and Rn, and when the optical system is a variable magnification optical system, Dn is set to a value in the variable magnification state in which the height of the on-axis marginal light from the optical axis reaches the maximum at the position of the second aperture, the optical system of the above-mentioned method preferably satisfies conditional formula (5) represented by the following formula:

[0017] 0<Dn / Rn<0.4 (5).

[0018] In a structure in which a concave lens surface in contact with air is located near the second aperture, the distance on the optical axis from the intersection of the lens surface and the optical axis to the second aperture is set to Dn, with respect to Dn, the sign of the distance on the image side is set to positive, and the sign of the distance on the object side is set to negative, with the intersection as a reference, the paraxial radius of curvature of the lens surface is set to Rn, the effective diameter of the lens surface is set to φEn, when there are two concave lens surfaces in contact with air located near the second aperture, the value of the lens surface having a diameter of the optically effective surface closer to the opening diameter of the second aperture is used for Dn, Rn and φEn, and when the optical system is a variable magnification optical system, Dn is set to a value in the variable magnification state in which the height of the on-axis marginal light from the optical axis reaches the maximum at the position of the second aperture, the optical system of the above-mentioned method preferably satisfies conditional formula (6) represented by the following formula:

[0019] 0.5<{Rn-Rn×(1-(φEn / 2) 2 / Rn 2 ) 1 / 2} / Dn<1.2 (6).

[0020] When the height of the principal ray of the maximum image height at the position of the second aperture from the optical axis is set to hp, the height of the on-axis marginal ray from the optical axis at the position of the second aperture is set to hm, and when the optical system is a variable-magnification optical system, hp and hm are set to values ​​in the variable-magnification state in which the height of the on-axis marginal ray from the optical axis at the position of the second aperture reaches the maximum, the optical system of the above-mentioned method preferably satisfies the conditional expression (7) represented by the following expression:

[0021] 0<|hp| / hm<1 (7).

[0022] The optical system of the above-described method preferably satisfies conditional expression (8) represented by the following equation, when the sum of the distance on the optical axis from the lens surface closest to the object side of the optical system to the lens surface closest to the image side of the optical system and the back focal length of the optical system at the air conversion distance is set to TL, the height of the principal ray of the maximum image height from the optical axis at the position of the second aperture is set to hp, the height of the on-axis marginal ray from the optical axis at the position of the second aperture is set to hm, and when the optical system is a variable-power optical system, Dst, TL, hp, and hm are set to values ​​in a variable-power state in which the height of the on-axis marginal ray from the optical axis at the position of the second aperture reaches the maximum.

[0023] 0.05<(|Dst| / TL) / (|hp| / hm)<1.8 (8).

[0024] When one lens component is set to a single lens or a group of cemented lenses, the composite focal length of all lens components closer to the object side than the second aperture is set to fs, and when the optical system is a variable power optical system, f and fs are set to values ​​in the variable power state where the height of the axial marginal light from the optical axis reaches the maximum at the position of the second aperture, the optical system of the above-mentioned method preferably satisfies the conditional expression (9) represented by the following expression:

[0025] -5<f / fs<5 (9).

[0026] Preferably, when focusing, the second aperture moves integrally with at least one lens of the optical system, or when focusing, the second aperture is integrally fixed with at least one lens of the optical system relative to the image plane. When the optical system is a zoom optical system, preferably, when zooming, the second aperture moves integrally with at least one lens of the optical system, or when zooming, the second aperture is integrally fixed with at least one lens of the optical system relative to the image plane.

[0027] The first aperture may be configured as an aperture that determines an F value.

[0028] An imaging device according to another aspect of the present invention includes the optical system according to the above aspect of the present invention.

[0029] In this specification, a "single lens" means a single lens that is not bonded. However, a composite aspherical lens (a lens in which a spherical lens and a film having an aspherical shape formed on the spherical lens are integrated and functions as a single aspherical lens as a whole) is not considered a bonded lens but is used as a single lens. Unless otherwise specified, the sign of the refractive power and the surface shape related to the lens including an aspherical surface use the sign of the refractive power and the surface shape of the paraxial region.

[0030] The "focal length" used in the conditional expression is the paraxial focal length. Unless otherwise specified, the "distance on the optical axis" used in the conditional expression is a geometric distance. Unless otherwise specified, the value used in the conditional expression is the value when the d-line is used as a reference in a state of focusing on an object at infinity. The "d-line", "C-line", "F-line" and "g-line" recorded in this specification are bright lines, and the wavelength of the d-line is used as 587.56nm (nanometers), the wavelength of the C-line is used as 656.27nm (nanometers), the wavelength of the F-line is used as 486.13nm (nanometers), and the wavelength of the g-line is used as 435.84nm (nanometers).

[0031] Effects of the Invention

[0032] According to the present invention, it is possible to provide an optical system that can achieve miniaturization, suppress a decrease in light quantity in the peripheral portion of an image, and improve image formation performance at an intermediate image height, and an imaging device including the optical system. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 Corresponding to the optical system of Example 1, this is a cross-sectional view showing the structure of an optical system according to an embodiment.

[0034] Figure 2 Yes means Figure 1 Structure of the optical system and cross-sectional view of the light beam.

[0035] Figure 3 This is a diagram for explaining symbols of each conditional expression.

[0036] Figure 4 The diagrams are spherical aberration diagram, astigmatism diagram, distortion diagram, and lateral chromatic aberration diagram of the optical system of Example 1.

[0037] Figure 5 This is a lateral aberration diagram of the optical system of Example 1.

[0038] Figure 6 It means from Figure 2 A cross-sectional view of the structure and light beam when the sub-aperture St1 is removed from the optical system.

[0039] Figure 7 yes Figure 6 Diagram of the lateral aberration of the optical system.

[0040] Figure 8 It is a cross-sectional view showing the structure of the optical system and the light beam of Example 2.

[0041] Fig. 9 1 and 2 are diagrams showing various aberrations of the optical system of Example 2.

[0042] Fig.10 It is a cross-sectional view showing the structure of the optical system and the light beam of Example 3.

[0043] Fig.11 1 and 2 are diagrams showing various aberrations of the optical system of Example 3.

[0044] Fig.12 It is a cross-sectional view showing the structure of the optical system and the light beam of Example 4.

[0045] Fig.13 1 and 2 are diagrams showing various aberrations of the optical system of Example 4.

[0046] Fig.14 It is a cross-sectional view showing the structure of the optical system and the light beam of Example 5.

[0047] Fig.15 1 and 1 are diagrams showing various aberrations of the optical system of Example 5.

[0048] Fig.16 It is a cross-sectional view showing the structure of the optical system and the light beam of Example 6.

[0049] Fig.17 1 and 2 are diagrams showing various aberrations of the optical system of Example 6.

[0050] Fig.18 This is a perspective view of the front side of the imaging device according to one embodiment.

[0051] Fig.19 This is a perspective view of the back side of the imaging device according to one embodiment. DETAILED DESCRIPTION

[0052] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0053] Figure 1 A cross-sectional view of the structure of an optical system according to an embodiment of the present invention is shown in FIG. Figure 1 In the figure, the left side is the object side and the right side is the image side. Figure 1 The example shown corresponds to the optical system of Example 1 described later.

[0054] As an example, Figure 1 The optical system includes 13 lenses, namely, lenses L1 to L13, in order from the object side to the image side.

[0055] exist Figure 1 In the example of FIG. 1 , an example is shown in which a parallel flat plate-shaped optical component PP is arranged between a lens closer to the image side and an image plane Sim, assuming that the optical component PP is applied to an image pickup device. The optical component PP is a component assumed to be various filters and / or a cover glass. The various filters are low-pass filters, infrared cut-off filters, and / or filters that cut off specific wavelength regions. The optical component PP is a component that does not have a refractive power. The image pickup device can also be configured by omitting the optical component PP.

[0056] Figure 1 The optical system includes a main aperture FS with a variable aperture diameter and four sub-apertures St1 to St4 with fixed aperture diameters.

[0057] The main aperture FS corresponds to the "first aperture" of the technique of the present invention. Figure 1 In the example of , the main aperture FS functions as an aperture that determines the F value. Figure 1 In the optical system, the main aperture FS is arranged between the lens L7 and the lens L8.

[0058] Three or more lenses including a positive lens and a negative lens are arranged on the object side of the main aperture FS. With such a configuration, various aberrations generated on the object side of the main aperture FS can be well corrected, especially spherical aberration and axial chromatic aberration.

[0059] The sub-apertures St1 to St4 correspond to the "second aperture" of the present invention. Figure 1 In the optical system, sub-apertures St1 to St4 are arranged as follows. Sub-aperture St1 is arranged adjacent to the object-side surface of lens L4 on the object side. Sub-aperture St2 is arranged so as to include the image-side surface of lens L6 in its opening. Sub-aperture St3 is arranged adjacent to the image-side surface of lens L9. Sub-aperture St4 is arranged adjacent to the image side of the image-side surface of lens L11. In addition, "adjacent" in this specification does not necessarily mean in contact, but means adjacent to each other.

[0060] In the following description, when there is no need to distinguish between the sub-apertures St1 to St4, they are simply referred to as “sub-apertures”. Figure 1 The optical system of the present invention includes four sub-apertures St1 to St4. However, in the technology of the present invention, the number of sub-apertures included in the optical system can be set arbitrarily.

[0061] The aperture diameter of the sub-aperture is constant, not variable. By configuring the aperture diameter of the sub-aperture to be constant, a mechanism for changing the aperture diameter of the sub-aperture is not required, which can contribute to miniaturization and also suppress the complexity of the mechanical mechanism.

[0062] By providing a sub-aperture separately from the main aperture FS that determines the F value, harmful light that causes coma flare and the like at the intermediate image height and degrades the imaging performance can be blocked. In this way, coma flare and the like at the intermediate image height can be suppressed, and thus the imaging performance at the intermediate image height can be improved. In the past, in order to block harmful light at the intermediate image height, in an optical system in which an aperture or a stopper is provided separately from the aperture that determines the F value, sometimes the light at the maximum image height is blocked, and in this case, the undesirable situation of reduced light amount in the peripheral part of the image occurs. In order to avoid such an undesirable situation, it is preferable to configure a sub-aperture near the main aperture FS.

[0063] Therefore, the optical system of the present invention is provided with a sub-aperture so as to satisfy the following conditional expression (1). Here, the distance on the optical axis from the main aperture FS to the sub-aperture is set to Dst. The focal length of the optical system is set to f. However, in the case where the optical system is a variable magnification optical system, Dst and f are set to the on-axis marginal ray B0m at the position of the sub-aperture (reference Figure 2 ) from the optical axis Z reaches the value in the maximum zoom state. As an example, Figure 1 denoted in the figure a distance Dst on the optical axis from the main aperture FS to the sub-aperture St1.

[0064] 0.005<|Dst| / f<2 (1)

[0065] By making the corresponding value of conditional expression (1) not exceed the upper limit, the position of the sub-aperture will not be too far away from the main aperture FS, so it is easy to prevent the sub-aperture from blocking the light of the maximum image height. As a result, it is possible to block harmful light of the intermediate image height while suppressing the decrease in the amount of light in the peripheral part of the image. In addition, by arranging the sub-aperture near the main aperture FS so that the corresponding value of conditional expression (1) does not exceed the upper limit, the outer diameter of the lens near the main aperture FS can be reduced, which is conducive to miniaturization of the optical system. For example, when the focus group that moves during focusing is arranged close to the main aperture FS, in the case where the sub-aperture is arranged inside the focus group, the outer diameter of the lens of the focus group can be reduced, so the focus group can be made lighter, which is conducive to high-speed focusing. In addition, for example, when the sub-aperture is arranged inside the moving group that moves during zooming, the outer diameter of the lens of the moving group can be reduced, so the moving group can be made lighter, which is conducive to reducing the load of the drive system that drives the moving group. By making the corresponding value of conditional expression (1) not be less than the lower limit, the sub-aperture will not be too close to the main aperture FS, so it is easy to configure the sub-aperture so that the main aperture unit does not interfere with the sub-aperture, and the main aperture unit includes a mechanism for changing the opening diameter of the main aperture FS.

[0066] In order to obtain better characteristics, it is preferable to use any one of 1.9, 1.8, 1.7, 1.6, 1.5, 1.4 and 1.3 instead of 2 which is the upper limit of conditional expression (1).

[0067] Furthermore, it is preferable to set the lower limit of conditional expression (1) to 0.007 or 0.008 instead of 0.005.

[0068] exist Figure 2 In Figure 1 The structure of the optical system and the cross-sectional view of the light beam. Figure 2 In the figure, as light beams, the axial light beam B0, the light beam B6 at 6 imaging heights, the light beam B10 at maximum image height, and the axial marginal light beam B0m are shown. The sub-apertures St1 to St4 block harmful light at 6 imaging heights without blocking the axial light beam B0 and the light beam B10 at maximum image height. The "6 imaging height" mentioned here means that the maximum image height is 10 imaging heights and the image height is expressed as a ratio relative to the maximum image height. This notation is the same for other image heights in this specification. In addition, in Figure 2 In FIG. 1 , a beam with an image height of 6 is shown as an example of a beam with an intermediate image height, but the “intermediate image height” of the technology of the present invention is not limited to the image height of 6. An image height greater than 0 and less than the maximum image height can be referred to as an “intermediate image height”.

[0069] In the following, conditional expressions that the optical system of the present invention further preferably satisfies are described. In order to avoid redundant descriptions in the descriptions related to the following conditional expressions, the same symbols are used for the same defined parts, and duplicate descriptions of some symbols are omitted.

[0070] The optical system of the present invention preferably satisfies the following conditional expression (2). Here, the opening diameter of the main aperture FS in the open state is set to φF. The opening diameter of the sub-aperture is set to φS. However, in the case where the optical system is a variable-power optical system, φF and φS are set to the values ​​in the variable-power state where the height of the on-axis marginal light ray B0m from the optical axis Z reaches the maximum at the position of the sub-aperture. As an example, Figure 1 2 shows the opening diameter φF of the main aperture FS in the open state and the opening diameter φS of the sub-aperture St1 .

[0071] 0.3<φS / φF<2.5 (2)

[0072] By making the corresponding value of conditional expression (2) not exceed the upper limit, the opening diameter of the sub-aperture will not become too large, so it is easy to block harmful light. By making the corresponding value of conditional expression (2) not exceed the lower limit, the opening diameter of the sub-aperture will not become too small, so it is easy to configure the sub-aperture not to block axial light.

[0073] In order to obtain better characteristics, it is preferable to set any value of 2.3, 2.2, 2.1, 2, and 1.9 instead of 2.5, which is the upper limit of conditional expression (2). Also, it is preferable to set any value of 0.4, 0.45, 0.5, 0.55, 0.6, and 0.65 instead of 0.3, which is the lower limit of conditional expression (2).

[0074] When a convex lens surface in contact with air is located within the opening of the sub-aperture, the optical system of the present invention preferably satisfies the following conditional expression (3). Figure 3 , the image side surface of the lens Lp is located within the opening of the sub-aperture St2. Figure 3 In the figure, the left side is the object side and the right side is the image side. The image side surface of lens Lp is a convex surface in contact with air. Here, the distance on the optical axis from the intersection of the lens surface and the optical axis Z to the sub-aperture of the lens surface in the opening is set as Dp. The paraxial curvature radius of the lens surface is set as Rp. As an example, in Figure 3 The distance Dp is shown in FIG. Regarding the sign of Dp, the sign of the distance on the image side is set to positive, and the sign of the distance on the object side is set to negative, based on the above-mentioned intersection point. Regarding the sign of the paraxial curvature radius in this specification, the sign of the paraxial curvature radius of the surface of the convex shape facing the object side is set to positive, and the sign of the paraxial curvature radius of the surface of the convex shape facing the image side is set to negative.

[0075] 0<Dp / Rp<0.4 (3)

[0076] By making the corresponding value of conditional expression (3) not be greater than the upper limit, the diameter of the optical effective surface of the lens and the effective diameter can be suppressed from becoming close to each other, which is conducive to improving processability and assemblability. By making the corresponding value of conditional expression (3) not be less than the lower limit, the lens having the lens surface and the sub-aperture in which the lens surface is located in the opening will not be too far apart, so the sub-aperture can be arranged without increasing the total length of the optical system, which is conducive to miniaturization.

[0077] If the lens having the lens surface and the sub-aperture whose lens surface is located in the opening are too far apart, a space for arranging the sub-aperture is required, which may increase the total length of the optical system.

[0078] In order to obtain better characteristics, it is preferable to set any value among 0.35, 0.3, 0.25, 0.2, 0.19 and 0.18 instead of 0.4 which is the upper limit of conditional expression (3).

[0079] In addition, the "optically effective surface" in this specification refers to a surface that can be used as an optical surface. And, the "effective diameter" in this specification refers to twice the distance from the intersection of the light ray passing through the outermost side and the lens surface to the optical axis Z among the light rays incident on the lens surface from the object side and emitted to the image side. The "outside" mentioned here refers to the radial outer side with the optical axis Z as the center, that is, the side away from the optical axis Z. And, in the case where the optical system is a variable magnification optical system, the "light ray passing through the outermost side" is determined by taking into account the entire variable magnification area.

[0080] When the convex lens surface in contact with the air is located within the opening of the secondary aperture, the optical system of the present invention preferably satisfies the following conditional expression (4). Here, the effective diameter of the lens surface is φEp. As an example, Figure 3 The half value of the above-mentioned effective diameter φEp is shown in FIG.

[0081] 0.7<{Rp-Rp×(1-(φEp / 2) 2 / Rp 2 ) 1 / 2} / Dp<1.5 (4)

[0083] By making the corresponding value of conditional expression (4) not be greater than the upper limit, the enlargement of the opening diameter of the sub-aperture can be suppressed, so that harmful light can be easily and effectively blocked. By making the corresponding value of conditional expression (4) not be less than the lower limit, it is easy to prevent not only harmful light but also necessary light from being blocked.

[0084] In order to obtain better characteristics, it is preferred to set the value to any one of 1.4, 1.35, 1.3, 1.25, 1.2 and 1.15 instead of 1.5, which is the upper limit of conditional expression (4). Also, it is preferred to set the value to any one of 0.75, 0.8, 0.85, 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98 and 0.99 instead of 0.7, which is the lower limit of conditional expression (4).

[0085] Furthermore, when the concave lens surface in contact with the air is located adjacent to the secondary aperture, the optical system of the present invention preferably satisfies the following conditional expression (5). Figure 3 The structure in which the object side surface of lens Ln is located adjacent to the sub-aperture St1 is shown in FIG. The object side surface of lens Ln is a concave surface in contact with air. Here, the distance on the optical axis from the intersection of the concave lens surface and the optical axis Z to the sub-aperture is set to Dn. The paraxial curvature radius of the concave lens surface is set to Rn. As an example, Figure 3The distance Dn is shown in . With respect to the sign of Dn, the sign of the distance on the image side is set to positive, and the sign of the distance on the object side is set to negative, with the above-mentioned intersection as a reference. In addition, with respect to one sub-aperture, when there are two concave lens surfaces in contact with the air at a position adjacent to the sub-aperture, that is, when the concave lens surface in contact with the air is located at a position adjacent to the object side and the image side of the sub-aperture, the value of the lens surface having the diameter of the optical effective surface closer to the value of the opening diameter of the sub-aperture among these two lens surfaces is used for Dn and Rn. And, when the optical system is a variable power optical system, Dn is set to the value in the variable power state when the height of the on-axis marginal light ray B0m from the optical axis Z reaches the maximum at the position of the sub-aperture.

[0086] 0<Dn / Rn<0.4 (5)

[0087] By making the corresponding value of conditional expression (5) not exceed the upper limit, the concave lens surface and the secondary aperture are not too far apart, so that the secondary aperture can be arranged without increasing the total length of the optical system, which is conducive to miniaturization. By making the corresponding value of conditional expression (5) below the lower limit, harmful light can be effectively blocked.

[0088] In order to obtain better characteristics, it is preferable to set any value among 0.3, 0.25, 0.2, 0.15, 0.13, 0.1 and 0.05 instead of 0.4 which is the upper limit of conditional expression (5).

[0089] When the concave lens surface in contact with the air is located adjacent to the secondary aperture, the optical system of the present invention preferably satisfies the following conditional expression (6). Here, the effective diameter of the concave lens surface is φEn. As an example, Figure 3 The half value of the above-mentioned effective diameter φEn is shown in FIG.

[0090] 0.5<{Rn-Rn×(1-(φEn / 2) 2 / Rn 2 ) 1 / 2} / Dn<1.2 (6)

[0092] By making the corresponding value of conditional expression (6) not be greater than the upper limit, the diameter of the optical effective surface of the lens and the effective diameter can be suppressed from becoming close to each other, which is conducive to improving processability and assemblability. By making the corresponding value of conditional expression (6) not be less than the lower limit, the concave lens surface and the sub-aperture are not too far apart, so the sub-aperture can be arranged without increasing the total length of the optical system, which is conducive to miniaturization.

[0093] In order to obtain better characteristics, it is preferable to set the upper limit of conditional expression (6) to any value of 1.2 instead of 1.1, 1.08, 1.06, 1.05, 1.04, 1.03, 1.02 and 1.01. It is also preferable to set the lower limit of conditional expression (6) to any value of 0.55, 0.6, 0.65, 0.7, 0.75 and 0.8 instead of 0.5.

[0094] Regarding the light height, the optical system of the present invention preferably satisfies the following conditional expression (7). Here, the height of the principal light ray B10p of the maximum image height from the optical axis Z at the position of the sub-aperture is set to hp. The height of the on-axis marginal light ray B0m from the optical axis Z at the position of the sub-aperture is set to hm. However, in the case where the optical system is a zoom optical system, hp and hm are set to the values ​​in the zoom state where the height of the on-axis marginal light ray B0m from the optical axis Z at the position of the sub-aperture reaches the maximum. As an example, in Figure 2 , the principal ray B10p of the maximum image height and the on-axis marginal ray B0m are shown, and hp and hm related to the sub-aperture St1 are also shown.

[0095] 0<|hp| / hm<1 (7)

[0096] By making the corresponding value of conditional expression (7) not exceed the upper limit, the sub-aperture can be arranged at a position where the height of the principal ray B10p at the maximum image height is lower than the height of the axial marginal ray B0m. This makes it easy to ensure the peripheral light amount at the maximum image height and only block harmful light at the intermediate image height. Regarding the lower limit of conditional expression (7), since |hp|>0 and hm>0, |hp| / hm>0.

[0097] In order to obtain better characteristics, it is preferable to set any value among 0.95, 0.9 and 0.85 instead of 1 which is the upper limit of conditional expression (7).

[0098] Furthermore, the optical system of the present invention preferably satisfies the following conditional expression (8). Here, the sum of the distance on the optical axis from the lens surface closest to the object side of the optical system to the lens surface closest to the image side of the optical system and the back focal length of the optical system at the air conversion distance is set to TL. TL is the total length of the optical system. In the case where the optical system is a variable magnification optical system, Dst, TL, hp, and hm are set to the values ​​in the variable magnification state where the height of the on-axis marginal light ray B0m from the optical axis Z reaches the maximum at the position of the sub-aperture.

[0099] 0.05<(|Dst| / TL) / (|hp| / hm)<1.8 (8)

[0100] By making the corresponding value of conditional expression (8) not exceed the upper limit, the position of the sub-aperture does not become too far away from the main aperture FS, so that the sub-aperture can be prevented from blocking the light reaching the maximum image height, thereby suppressing the reduction of light amount in the peripheral part of the image.

[0101] By making the corresponding value of conditional expression (8) not be less than the lower limit, the sub-aperture will not be too close to the main aperture FS, so it is easy to configure the sub-aperture so that the main aperture unit and the sub-aperture do not interfere with each other. The main aperture unit includes a mechanism for changing the opening diameter of the main aperture FS.

[0102] In order to obtain better characteristics, it is preferable to set the value to any one of 1.7, 1.6, 1.5, 1.4, 1.3, 1.2, 1.1, 1 and 0.9 instead of 1.8, which is the upper limit of conditional expression (8). Furthermore, it is preferable to set the value to any one of 0.06, 0.07, 0.08, 0.09, 0.1, 0.11 and 0.12 instead of 0.05, which is the upper limit of conditional expression (8).

[0103] The optical system of the present invention preferably satisfies the following conditional formula (9). Here, the composite focal length of all lens components closer to the object side than the sub-aperture is set to fs. In addition, one lens component represents a single lens or a group of cemented lenses. In the case where the optical system is a zoom optical system, f and fs are set to the values ​​in the zoom state where the height of the on-axis marginal ray B0m from the optical axis Z reaches the maximum at the position of the sub-aperture.

[0104] -5<f / fs<5 (9)

[0105] By making the corresponding value of conditional expression (9) not exceed the upper limit in the range of f / fs>0, it is easy to effectively block harmful light at the intermediate image height without blocking the light reaching the maximum image height by the sub-aperture. By making the corresponding value of conditional expression (9) not exceed the lower limit in the range of f / fs<0, it is possible to prevent the light beam from being greatly diverged near the sub-aperture. Therefore, it is easy to effectively block harmful light at the intermediate image height without blocking the axial light at the position of the sub-aperture.

[0106] In order to obtain better characteristics, it is preferable to set any value among 4.5, 4, 3.5, 3, 2.5, 2.4, 2.3, 2.2, 2.1, 2, 1.9, 1.8, 1.7, 1.6, 1.5, 1.4, 1.3, 1.2 and 1.1 instead of 5, which is the upper limit of conditional expression (9). It is also preferable to set any value among -4.5, -4, -3.5, -3, -2.5, -2.4, -2.3, -2.2, -2.1, -2, -1.9, -1.8, -1.7 and -1.6 instead of -5, which is the lower limit of conditional expression (9).

[0107] For example, in Figure 1 In the optical system, the lens L1 as a single lens is 1 lens component. Figure 1 The first lens component from the object side is in the optical system of . The cemented lens formed by cementing lens L2 and lens L3 is also a single lens component and Figure 1 The second lens component from the object side in the optical system. The cemented lens formed by cementing lens L4 and lens L5 is also a single lens component and Figure 1 The third lens component from the object side in the optical system. Lens L6, which is a single lens, is also a single lens component. Figure 1 The optical system is the fourth lens component from the object side. The above “all lens components closer to the object side than the sub-aperture” means the lens components that are located as a whole closer to the object side than the sub-aperture, not the lens components that are partially located closer to the object side than the sub-aperture. Figure 1 When the conditional expression (9) is taken into consideration for the sub-aperture St2, a part of the lens surface of the lens L6 is located within the opening of the sub-aperture St2, so the lens L6 is not a lens component closer to the object side than the sub-aperture St2. Figure 1 In the optical system, all the lens components closer to the object side than the sub-aperture St2 refer only to the first, second and third lens components from the object side.

[0108] The sub-aperture preferably moves integrally with at least one lens of the optical system during focusing, or is fixed integrally with at least one lens of the optical system relative to the image plane Sim during focusing. Furthermore, when the optical system is a zoom optical system, the sub-aperture preferably moves integrally with at least one lens of the optical system during zooming, or is fixed integrally with at least one lens of the optical system relative to the image plane Sim during zooming.

[0109] In this case, there is no need to provide a mechanism for moving the sub-aperture separately from the mechanism for moving the lens, which can contribute to miniaturization and also suppress the complexity of the mechanical mechanism. In addition, in this specification, "moving integrally" means moving at the same time by the same amount and in the same direction.

[0110] For example, in Figure 2 In the optical system, when focusing, lenses L8~L13 and sub-apertures St3~St4 move integrally along the optical axis Z, and lenses L1~L7, main aperture FS and sub-apertures St1~St2 are integrally fixed relative to the image plane Sim. Figure 2 The brackets and leftward arrows below the lenses L8 to L13 and sub-apertures St3 to St4 indicate that these are the focusing groups that move toward the object side when focusing from an object at infinity to an object at a close distance.

[0111] The above-mentioned preferred structures and possible structures may be any combination, and are preferably appropriately and selectively adopted according to the required specifications.

[0112] Next, embodiments of the optical system of the present invention are described with reference to the accompanying drawings. In addition, the reference symbols marked on the lenses or lens groups in the cross-sectional views of each embodiment are used independently in each embodiment to avoid the complication of the description and drawings caused by the increase in the number of digits of the reference symbols. Therefore, even if the same reference symbols are marked in the drawings of different embodiments, they are not necessarily the same structure.

[0113] [Example 1]

[0114] The structure of the optical system and the cross-sectional view of the light beam of Example 1 are shown in Figure 1 and Figure 2 , the diagram method and structure are as described above, so some repeated descriptions are omitted here. The optical system of Example 1 includes lenses L1 to L13 in order from the object side to the image side. The optical system of Example 1 includes a main aperture FS with a variable opening diameter and sub-apertures St1 to St4 with fixed opening diameters.

[0115] Regarding the optical system of Example 1, the basic lens data is shown in Table 1, the specifications are shown in Table 2, and the aspheric coefficients are shown in Table 3. The table of basic lens data is recorded as follows. In the Sn column, the surface number of each surface when the surface closest to the object side is set as the first surface and the next surface is numbered in a manner of increasing the number one by one is shown. The radius of curvature of each surface is shown in the R column. In the sign of the radius of curvature, the radius of curvature of the surface with a convex shape facing the object side is set to positive, and the radius of curvature of the surface with a convex shape facing the image side is set to negative. The surface spacing on the optical axis of each surface and the next surface is shown in the D column. In the sign of the surface spacing, the spacing in the image side direction is set to positive, and the spacing in the object side direction is set to negative. The value of the bottom column of the D column is the spacing between the surface closest to the image side in the table and the image plane Sim. The refractive index of each component relative to the d-line is shown in the Nd column. The Abbe number of the d-line reference of each component is shown in the vd column. The optical component PP is also shown in the table of basic lens data.

[0116] In the table of basic lens data, in the surface corresponding to the main aperture FS, the surface number and "(FS)" are written in the surface number column, and "main aperture" is written in the right column of the surface interval. In the surface corresponding to the sub-aperture St1, "sub-aperture St1" is written in the right column of the surface interval, and its opening diameter is written after "φ". The surfaces corresponding to the sub-apertures St2 to St4 are also written in the same way as the surface corresponding to the sub-aperture St1.

[0117] Table 2 shows the focal length f when focusing on an object at infinity, the back focus Bf at the air conversion distance, the open F value FNo., the maximum total angle of view 2ω, the aperture diameter φF of the main aperture FS when open, and the total length TL of the optical system based on the d-line. The [°] in the column of the maximum total angle of view indicates that the unit is degree.

[0118] In the basic lens data, the surface number of the aspheric surface is marked with an * mark, and the value of the paraxial curvature radius is recorded in the column of the curvature radius of the aspheric surface. In Table 3, the surface number of the aspheric surface is shown in the Sn row, and the values ​​of the aspheric coefficients of each aspheric surface are shown in the KA and Am rows. In addition, m in Am is an integer greater than 3 and is different for each surface.

[0119] For example, in the first surface of Example 1, m=3, 4, 5, ..., 16. The numerical values ​​of the aspherical coefficients in Table 3, "E±n" (n: integer), represent "×10 ±n KA and Am are aspherical coefficients in the aspherical formula represented by the following formula.

[0120] Zd=C×h 2 / {1+(1-KA×C 2 ×h 2 ) 1 / 2}+∑Am×h m

[0121] in,

[0122] Zd: depth of aspheric surface (the length of the perpendicular line from a point on the aspheric surface at height h to a plane tangent to the vertex of the aspheric surface and perpendicular to the optical axis Z);

[0123] h: height (the distance from the optical axis Z to the lens surface);

[0124] C: the reciprocal of the paraxial curvature radius;

[0125] KA, Am: Aspheric coefficients,

[0126] Σ in the aspherical expression represents the sum related to m.

[0127] In the data of each table, degrees are used as the unit of angle, and mm (millimeter) is used as the unit of length. Since the optical system can be used in both enlarged and reduced proportions, other appropriate units can also be used. In addition, the values ​​rounded to a preset number of digits are recorded in each table shown below.

[0128] [Table 1] Example 1

[0129]

[0130] [Table 2]

[0131] Example 1

[0132] f 18.20 Bf 19.49 FNo. 1.44 2ω[°] 76.4 φF 23.07 TL 89.41

[0133] [Table 3]

[0134] Example 1

[0135] Sn 1 2 26 27 KA -3.5524107E+00 -4.3839153E-01 -8.7749470E-01 -1.7564944E+00 A3 0.0000000E+00 0.0000000E+00 0.0000000E+00 0.0000000E+00 A4 1.4562563E-04 1.9987653E-04 -2.9457203E-04 4.5987345E-05 A5 -1.5586134E-05 -1.4237156E-05 -3.0213717E-05 -4.2734089E-05 A6 5.2002049E-07 3.8653493E-08 8.8294930E-06 8.3923312E-06 A7 4.4576460E-08 9.7639392E-08 -6.3236083E-07 -6.7249893E-07 A8 -7.2822532E-09 1.3127811E-10 6.6065017E-08 3.8700650E-08 A9 2.3897513E-10 -1.7402613E-09 -1.8681912E-08 -1.0369127E09 A10 2.0729060E-11 1.0104915E-10 2.8496418E-09 -7.1101541E-10 A11 -4.2346876E-13 1.0980116E11 -2.1192026E10 1.4318222E10 A12 -2.6304469E-13 -1.4408297E-12 5.7452181E-12 -4.3454846E-12 A13 2.7068251E-14 5.0098114E-14 1.3592773E-13 -1.7638060E-12 A14 -1.2272789E-15 2.0411475E-16 -3.2656663E-15 2.5353158E-13 A15 2.8191990E-17 -5.1685374E-17 -6.9338244E-16 -1.4072532E-14 A16 -2.6907030E-19 9.6690889E-19 2.5709964E-17 2.9452493E-16

[0136] exist Figure 4 and Figure 5 , various aberration diagrams of the optical system of Example 1 in a state where the optical system is focused on an infinitely distant object are shown. Figure 4 In the figure, spherical aberration, astigmatism, distortion aberration and lateral chromatic aberration are shown from left to right. In the spherical aberration diagram, aberrations at the d-line, C-line and F-line are shown with solid lines, long dashed lines and short dashed lines, respectively. In the astigmatism diagram, aberrations at the d-line in the sagittal direction are shown with solid lines, and aberrations at the d-line in the meridional direction are shown with short dashed lines. In the distortion aberration diagram, aberrations at the d-line are shown with solid lines. In the lateral chromatic aberration diagram, aberrations at the C-line and F-line are shown with long dashed lines and short dashed lines, respectively. In the spherical aberration diagram, the value of the open F value is shown after "FNo.=". In the other aberration diagrams, the value of the maximum half field of view angle is shown after "ω=".

[0137] exist Figure 5 In FIG. 1 , the lateral aberrations on the axis (i.e., image height 0), 2 image heights, 4 image heights, 6 image heights, 8 image heights, and at the maximum image height are shown from the top. Figure 5 In FIG. 1 , aberrations at the d-line, C-line, F-line, and g-line are respectively indicated by a solid line, a long dashed line, a short dashed line, and a dashed-dotted line. Figure 5 The unit of the vertical axis is μm (micrometer).

[0138] For comparison, Figure 6 , a cross-sectional view of the structure and light beam when the sub-aperture St1 is removed from the optical system of Example 1. Figure 6 In the figure, as the light beams, the on-axis light beam B0, the light beam B6 with high image height, and the light beam B10 with maximum image height are shown. Figure 2 and Figure 6 , the on-axis beam B0 and the beam B10 with the maximum image height are the same, but the lower ray of the beam B6 with the maximum image height is at a different height from the optical axis Z. More specifically, in the lens closer to the object side than the main aperture FS, the absolute value of the height of the lower ray of the beam B6 from the optical axis Z is observed to be Figure 2 Compare Figure 6 That is, among the axial light, the light of 6 image height and the light of maximum image height, the sub-aperture St1 only blocks the light of 6 image height without blocking the axial light and the light of maximum image height.

[0139] Figure 7 Shown in Figure 6 Lateral aberration diagram of the optical system shown. Figure 7 The graphical representation method and the units of the vertical axis are Figure 5 Same, in Figure 7 In the figure, the lateral aberrations on the axis (i.e., image height 0), 2 image heights, 4 image heights, 6 image heights, 8 image heights, and at the maximum image height are shown from the top. Figure 5 and Figure 7 , the images on the axis and at the maximum image height are the same, but differences are observed in the images at the intermediate image heights. The most obvious difference is that in the images at 4 image heights and 6 image heights, Figure 7 The area surrounded by the dotted rectangle has a large amount of aberration. Figure 5 It is not observed in the image. From this, it can be seen that the sub-aperture St1 effectively blocks the lower side light of the 4th image height and the 6th image height that produces coma flare, etc., without blocking the axial light beam B0 and the light beam B10 at the maximum image height. In other words, it can be seen that the image forming performance at the intermediate image height is improved by the sub-aperture St1 without reducing the light amount of the peripheral part of the image.

[0140] [Example 2]

[0141] The structure of the optical system and the cross-sectional view of the light beam of Example 2 are shown in Figure 8 . The optical system of Example 2 includes lenses L1 to L12 in sequence from the object side to the image side. The optical system of Example 2 includes a main aperture FS with a variable opening diameter and a sub-aperture St1 with a fixed opening diameter. The main aperture FS functions as an aperture that determines the F value. The main aperture FS is arranged between lens L4 and lens L5. The sub-aperture St1 is arranged to include the object side surface of lens L5 in its opening. When focusing from an object at infinity to an object at a close distance, lenses L5 to lens L9 and sub-aperture St1 move integrally toward the object side along the optical axis Z, and lenses L1 to L4, lenses L10 to L12 and the main aperture FS are fixed relative to the image plane Sim.

[0142] Regarding the optical system of Example 2, basic lens data is shown in Table 4, specifications are shown in Table 5, aspheric coefficients are shown in Table 6, and various aberration diagrams when focusing on an infinitely distant object are shown in Table 8. Fig. 9 . Fig. 9 The graphical method of Example 1 Figure 4 The symbols, meanings, recording methods and illustration methods of the data in other embodiments 2 are also the same as those in embodiment 1. Unless otherwise specified, the symbols, meanings, recording methods and illustration methods of the data after embodiment 3 are also basically the same, so repeated descriptions are omitted below.

[0143] [Table 4] Example 2

[0144]

[0145] [Table 5]

[0146] Example 2

[0147] f 34.01 Bf 13.24 FNo. 1.44 2ω[°] 45.4 φF 25.61 TL 76.07

[0148] [Table 6]

[0149] Example 2

[0150] Sn 17 18 22 23 KA 1.0000000E+00 1.0000000E+00 1.0000000E+00 1.0000000E+00 A3 0.0000000E+00 0.0000000E+00 0.0000000E+00 0.0000000E+00 A4 -6.7892977E+06 2.6728027E+05 2.0699818E+05 2.6025700E+05 A5 -3.4998037E+06 -3.1585103E+06 -3.5609821E+06 2.0701497E+05 A6 2.6708753E+07 3.6167193E+08 1.0411116E+06 -3.2441813E+06 A7 4.1719229E+08 5.7847224E+08 -4.6385997E-08 2.0830649E-07 A8 -4.6906387E-09 -3.6372615E-09 -1.0004409E-08 8.0249345E-09 A9 -2.1393790E-10 -3.2271859E-10 6.1558719E-10 -2.2013977E-09 A10 3.2807144E-11 2.9770156E+11 2.8180923E+11 7.4088106E+11 A11 3.7083422E-13 6.2009046E-13 -1.8453397E-12 4.8533222E-12 A12 -7.9543983E-14 -7.1537115E-14 -2.8600819E-14 -2.7168254E-13

[0151] [Example 3]

[0152] The structure of the optical system and the cross-sectional view of the light beam of Example 3 are shown in Fig.10 . The optical system of Example 3 includes lenses L1 to L13 in order from the object side to the image side. The optical system of Example 3 includes a main aperture FS with a variable opening diameter and sub-apertures St1 to St3 with fixed opening diameters. The main aperture FS functions as an aperture that determines the F value. The main aperture FS is arranged between lens L6 and lens L7. The sub-aperture St1 is arranged to include the image-side surface of lens L4 in its opening. The sub-aperture St2 is arranged adjacent to the image side of the image-side surface of lens L6. The sub-aperture St3 is arranged adjacent to the image side of the image-side surface of lens L8. When focusing from an infinitely distant object to a close-up object, lenses L5 to L9, the main aperture FS, and the sub-apertures St2 to St3 move integrally toward the object side along the optical axis Z, and lenses L1 to L4, lenses L10 to L13, and the sub-aperture St1 are fixed relative to the image plane Sim.

[0153] Regarding the optical system of Example 3, basic lens data is shown in Table 7, specifications are shown in Table 8, aspheric coefficients are shown in Table 9, and various aberration diagrams when focusing on an infinitely distant object are shown in Table 10. Fig.11 .

[0154] [Table 7] Example 3

[0155]

[0156] [Table 8]

[0157] Example 3

[0158] f 30.91 Bf 26.52 FNo. 3.57 2ω[°] 84.4 φF 14.96 TL 117.47

[0159] [Table 9]

[0160] Example 3

[0161] Sn 1 2 19 20 KA 1.0000000E+00 1.0000000E+00 1.0000000E+00 1.0000000E+00 A3 0.0000000E+00 0.0000000E+00 0.0000000E+00 0.0000000E+00 A4 1.7190323E-06 -1.0324755E-05 -3.6874743E-05 -1.7507432E-05 A5 -7.4474335E-07 -9.9518618E-07 1.5262016E-06 1.8963888E-06 A6 3.0051321E-08 6.4950083E-09 2.2784479E-07 -1.6630172E-07 A7 8.1417469E-12 1.0528595E-09 -9.8209300E-08 4.0718008E-08 A8 2.6419440E-11 -1.9802457E-10 4.2866430E-10 3.0729611E-09 A9 -8.4613032E-13 9.3801528E-12 1.4337539E-09 2.2019263E-10 A10 -6.7674963E-14 -2.6840622E-14 4.1053517E-11 -1.0135846E-11 A11 -5.2825214E-15 -9.6141003E-14 -1.4808362E-11 -1.3635971E-12 A12 1.3685955E-17 9.2320265E-15 -7.4799199E-13 3.6925212E-14 A13 -2.1817230E-17 -9.7218804E-16 9.9226988E-14 -2.6847120E-14 A14 1.9880799E-18 3.3672325E-17 2.1856025E-15 1.3212027E-15 A15 7.8661839E-20 4.2370872E-18 2.2178857E-16 1.8274698E-16 A16 9.0261546E-21 -9.1536371E-19 -2.2420853E-16 3.5944816E-17 A17 5.4358767E-22 7.0329374E-20 3.2929455E-17 -3.1433068E-18 A18 -4.4806487E-23 -3.5736344E-22 2.2161945E-19 6.0753510E-19 A19 2.0403062E-24 1.5453784E-22 -2.7567893E-19 6.0854810E-20 A20 -5.5439226E-27 3.7714093E-24 1.1764954E-20 -9.4474266E-22

[0162] [Example 4]

[0163] The structure of the optical system and the cross-sectional view of the light beam of Example 4 are shown in Fig.12 . The optical system of Example 4 includes lenses L1 to L13 in sequence from the object side to the image side. The optical system of Example 4 includes a main aperture FS with a variable opening diameter and sub-apertures St1 to St2 with fixed opening diameters. The main aperture FS functions as an aperture that determines the F value. The main aperture FS is arranged between lens L5 and lens L6. The sub-aperture St1 is arranged to include the image side surface of lens L8 in its opening. The sub-aperture St2 is arranged to include the image side surface of lens L10 in its opening. When focusing, lenses L3 to L10, the main aperture FS and the sub-apertures St1 to St2 move integrally toward the object side along the optical axis Z, and lenses L1 to L2 and lenses L11 to L13 are fixed relative to the image plane Sim.

[0164] Regarding the optical system of Example 4, basic lens data is shown in Table 10, specifications are shown in Table 11, aspheric coefficients are shown in Table 12, and various aberration diagrams when focusing on an infinitely distant object are shown in Table 13. Fig.13 .

[0165] [Table 10] Example 4

[0166]

[0167] [Table 11] Example 4

[0168] f 56.67 Bf 20.50 FNo. 1.75 2ω[°] 52.0 φF 27.29 TL 122.24

[0169] [Table 12]

[0170] Example 4

[0171] Sn 11 12 24 25 KA 1.0000000E+00 1.0000000E+00 1.0000000E+00 1.0000000E+00 A4 -2.0370108E-05 -1.4890456E-05 -2.5350781E-05 -2.0566239E-05 A6 -2.2837244E-08 -1.4092898E-08 5.0780164E-08 5.3699159E-08 A8 1.5881928E-10 1.4530204E-10 -5.4993528E-11 -5.6857976E-11 A10 -2.7238168E-13 -2.5033093E-13 4.3033371E-14 4.1725261E-14

[0172] [Example 5]

[0173] The structure of the optical system and the cross-sectional view of the light beam of Example 5 are shown in Fig.14 The optical system of Example 5 is a zoom lens. Fig.14 In the figure, the wide-angle end state is shown in the upper section marked with "wide-angle end", and the telephoto end state is shown in the lower section marked with "telephoto end". The optical system of Example 5 includes, from the object side to the image side, the first lens group G1, the second lens group G2, the third lens group G3, the fourth lens group G4, and the fifth lens group G5. When changing the magnification, the second lens group G2, the third lens group G3, and the fourth lens group G4 move along the optical axis Z by changing the intervals with the adjacent lens groups, and the first lens group G1 and the fifth lens group G5 are fixed relative to the image plane Sim. Fig.14Between the upper and lower sections, the lens group that moves when changing magnification is indicated by arrows, which roughly indicate the movement trajectory when changing magnification from the wide-angle end to the telephoto end. The lens group that is fixed when changing magnification is indicated by a ground mark.

[0174] The optical system of Example 5 includes a main aperture FS with a variable aperture diameter and sub-apertures St1 to St2 with fixed aperture diameters. The main aperture FS functions as an aperture that determines the F value. The main aperture FS is arranged on the object side of the fifth lens group G5. The sub-aperture St1 is arranged so as to include the object side surface of the lens on the object side of the third lens group G3 within its opening. The sub-aperture St2 is arranged so as to include the object side surface of the fifth lens from the image side of the fifth lens group G5 within its opening. The sub-aperture St1 and the sub-aperture St2 block harmful light of the intermediate image height at the wide-angle end.

[0175] During zooming, the sub-aperture St1 moves integrally with the lenses of the third lens group G3 along the optical axis Z, and the main aperture FS and the sub-aperture St2 are integrally fixed with the lenses of the fifth lens group G5 relative to the image plane Sim. The focus group includes the fourth lens group G4. Fig.14 The brackets and leftward arrow above the 4th lens group G4 indicate that when focusing from an infinitely distant object to a close object, the 4th lens group G4 is a focus group that moves toward the object side. When focusing, the lenses of the lens groups other than the 4th lens group G4, the main aperture FS, and the sub-apertures St1 to St2 are fixed integrally relative to the image plane Sim.

[0176] The basic lens data of the optical system of Example 5 is shown in Table 13. In the table of basic lens data, the symbol DD[] is used for the variable surface interval when changing the magnification, and the surface number on the object side of the interval is marked in [] and recorded in the column of surface interval. The specifications and variable surface intervals of the optical system of Example 5 are shown in Table 14. In Table 14, the columns marked with "wide-angle end" show the values ​​of the wide-angle end state, and the columns marked with "telephoto end" show the values ​​of the telephoto end state. Table 14 also shows the zoom ratio. Fig.15 , various aberration diagrams are shown in the state where the optical system of Example 5 is focused on an object at infinity. Fig.15 , the upper section labeled “wide-angle end” shows aberrations in the wide-angle end state, and the lower section labeled “telephoto end” shows aberrations in the telephoto end state.

[0177] [Table 13]

[0178] Example 5

[0179]

[0180] [Table 14]

[0181] Example 5

[0182] Wide angle Telephoto end Zoom ratio 1.0 3.8 f 154.65 583.13 Bf 58.83 58.83 FNo. 5.77 8.25 2ω[°] 10.4 2.8 φF 24.74 17.04 TL 319.87 319.87 DD[6] 29.41 102.48 DD

[12] 82.07 2.74 DD

[20] 20.83 33.85 DD

[24] 13.87 7.12

[0183] [Example 6]

[0184] The structure of the optical system and the cross-sectional view of the light beam of Example 6 are shown in Fig.16 . The optical system of Example 6 is a zoom lens. The method of recording data and the method of illustrating the diagram of the optical system of Example 6 are basically the same as those of Example 5, so some repeated descriptions are omitted here. The optical system of Example 6 includes the first lens group G1, the second lens group G2, the third lens group G3, the fourth lens group G4, and the fifth lens group G5 from the object side to the image side. When changing the magnification, the second lens group G2 and the fourth lens group G4 move along the optical axis Z, and the first lens group G1, the third lens group G3 and the fifth lens group G5 are fixed relative to the image plane Sim.

[0185] The optical system of Example 6 includes a main aperture FS with a variable aperture diameter and sub-apertures St1 and St2 with fixed aperture diameters. The main aperture FS functions as an aperture that determines the F value. The main aperture FS is arranged on the object side of the third lens group G3. The sub-aperture St1 is arranged so as to include the image side surface of the lens closest to the image side of the second lens group G2 in its opening. The sub-aperture St2 is arranged so as to include the image side surface of the lens closest to the image side of the third lens group G3 in its opening. The sub-aperture St1 and the sub-aperture St2 block harmful light at the intermediate image height at the telephoto end.

[0186] During zooming, the sub-aperture St1 moves integrally with the lenses of the second lens group G2 along the optical axis Z, and the main aperture FS and the sub-aperture St2 are integrally fixed with the lenses of the third lens group G3 relative to the image plane Sim. The focus group includes the fourth lens group G4. Fig.16 The brackets and rightward arrow above the 4th lens group G4 indicate that the 4th lens group G4 is a focus group that moves toward the image side when focusing from an infinitely distant object to a close object. When focusing, the lenses of the lens groups other than the 4th lens group G4, the main aperture FS, and the sub-apertures St1 to St2 are fixed integrally relative to the image plane Sim.

[0187] Regarding the optical system of Example 6, basic lens data is shown in Table 15, specifications and variable surface intervals are shown in Table 16, aspheric coefficients are shown in Table 17, and various aberration diagrams when focusing on an infinitely distant object are shown in Table 18. Fig.17 .

[0188] [Table 15] Example 6

[0189]

[0190] [Table 16]

[0191] Example 6

[0192] Wide angle Telephoto end Zoom ratio 1.0 6.3 f 18.54 116.77 Bf 22.66 22.66 FNo. 4.09 4.12 2ω[°] 77.8 12.8 φF 14.33 16.51 TL 144.32 144.32 DD[7] 1.01 31.03 DD

[16] 31.41 1.38 DD

[23] 2.67 14.16 DD

[26] 21.80 10.31

[0193] [Table 17]

[0194] Example 6

[0195] Sn 8 9 27 28 KA 1.0000000E+00 1.0000000E+00 1.0000000E+00 1.0000000E+00 A4 6.3654280E-05 5.8115700E-05 -3.3313022E-07 1.5864674E-05 A6 -1.6520578E-06 -8.6702710E-07 -3.1035733E-07 4.6814967E-07 A8 3.6308297E-08 -4.5783717E-08 1.3953513E-08 -2.8075495E-08 A10 -6.2436489E-10 3.8246956E-09 -1.9091620E-10 9.8406524E-10 A12 7.5884189E-12 -1.3330761E-10 -7.6081743E-13 -1.9031014E-11 A14 -6.0903631E-14 2.6082780E-12 5.1744107E-14 2.1392501E-13 A16 3.0342366E-16 -2.9426472E-14 -5.9555663E-16 -1.3822383E-15 A18 -8.4569318E-19 1.7856370E-16 2.9430982E-18 4.7328661E-18 A20 1.0050279E-21 -4.5150703E-19 -5.4890319E-21 -6.6078617E-21

[0196] Sn 18 19 KA 1.0000000E+00 1.0000000E+00 A3 0.0000000E+00 0.0000000E+00 A4 -3.8865422E-05 7.1075371E-05 A5 7.6564967E-05 -2.3245540E-05 A6 -7.1121281E-05 8.8240861E-06 A7 3.1399739E-05 -1.6886838E-06 A8 -7.0470848E-06 1.8063804E-07 A9 5.5583077E-07 -1.8197456E-08 A10 9.7347054E-08 2.8022294E-09 A11 -2.8941874E-08 -6.9908347E-11 A12 2.6732043E-09 6.6561840E-11 A13 -2.3823750E-11 9.3073733E-12 A14 -1.4334971E-11 -2.8836404E-13 A15 1.0709284E-12 1.8458979E-14 A16 -2.5308020E-14 1.0024286E-15

[0197] Table 18 shows the values ​​related to conditional expressions (1) and (2) for the optical systems of Examples 1 to 6. In the leftmost column of Table 18, the example number and the corresponding sub-aperture symbol are recorded, and for the examples of the variable-magnification optical system, the variable-magnification state of the value used for calculation is shown after the sub-aperture symbol.

[0198] Among them, "Wide" indicates the wide-angle end, and "Tele" indicates the telephoto end. The display method of the leftmost column is also the same as that of Tables 19 to 22 described later. Regarding the sign of Dst, the sign of the distance on the image side is set to positive, and the sign of the distance on the object side is set to negative, based on the main aperture FS. In Table 18, the columns of corresponding values ​​of conditional expressions (1) and (2) are surrounded by bold lines, and (1) and (2) are recorded thereon, respectively.

[0199] [Table 18]

[0200]

[0201] Table 19 shows the values ​​related to conditional expressions (3) and (4) for the optical systems of Examples 1 to 6. Here, dhp={Rp-Rp×(1-(φEp / 2) 2 / Rp 2 ) 1 / 2 In Table 19, the columns of corresponding values ​​of conditional expressions (3) and (4) are surrounded by bold lines, and (3) and (4) are recorded above them, respectively.

[0202] [Table 19]

[0203]

[0204] Table 20 shows the values ​​related to conditional expressions (5) and (6) for the optical systems of Examples 1 to 6. Here, dhn={Rn-Rn×(1-(φEn / 2) 2 / Rn 2 ) 1 / 2}.

[0205] In Table 20, the columns of corresponding values ​​of conditional expressions (5) and (6) are surrounded by bold lines, and (5) and (6) are recorded above them, respectively.

[0206] [Table 20]

[0207]

[0208] In Table 21, values ​​related to conditional expressions (7) and (8) are shown for the optical systems of Examples 1 to 6. The definition of the sign of Dst is the same as that of Table 18. Regarding the sign of hp, in each cross-sectional view, the height of the light on the upper side of the optical axis Z is set to positive, and the sign of the height of the light on the lower side is set to negative. In Table 21, the columns of corresponding values ​​of conditional expressions (7) and (8) are surrounded by bold lines, and (7) and (8) are recorded above them, respectively.

[0209] [Table 21]

[0210]

[0211] Table 22 shows values ​​related to conditional expression (9) for the optical systems of Examples 1 to 6. In Table 22, columns corresponding to values ​​of conditional expression (9) are surrounded by bold lines, and (9) is written above them.

[0212] [Table 22]

[0213]

[0214] Next, an imaging device according to an embodiment of the present invention will be described. Fig.18 and Fig.19 2 shows an external view of a camera 30 as an imaging device according to an embodiment of the present invention. Fig.18 1 is a perspective view showing the camera 30 as viewed from the front side. Fig.19 The camera 30 is a perspective view viewed from the back. The camera 30 is a so-called mirrorless digital camera, and the interchangeable lens 20 can be detachably mounted. The interchangeable lens 20 includes the optical system 1 according to one embodiment of the present invention housed in a lens barrel.

[0215] The camera 30 includes a camera body 31, and a shutter button 32 and a power button 33 are provided on the upper surface of the camera body 31. In addition, an operation unit 34, an operation unit 35, and a display unit 36 ​​are provided on the back surface of the camera body 31. The display unit 36 ​​can display the captured image and the image existing in the field of view before the capture.

[0216] A photographing opening through which light from a photographic subject enters is provided at the center of the front surface of the camera body 31 , and a bayonet mount 37 is provided at a position corresponding to the photographing opening. The interchangeable lens 20 is mounted on the camera body 31 via the bayonet mount 37 .

[0217] An imaging element such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor) that outputs an imaging signal corresponding to an image of a subject formed by the interchangeable lens 20, a signal processing circuit that processes the imaging signal output from the imaging element to generate an image, and a recording medium for recording the generated image are provided in the camera body 31. In the camera 30, a still image or a moving image can be captured by pressing a shutter button 32, and the image data obtained by the capturing is recorded in the above-mentioned recording medium.

[0218] In the above, the technology of the present invention is described by citing the implementation modes and examples, but the technology of the present invention is not limited to the above implementation modes and examples, and various deformations can be made. For example, the number of lenses and the number of lens groups constituting the optical system are not limited to the above examples. The variable magnification optical system is not limited to a zoom lens, but can also be a variable focal length lens. The sub-aperture can be arranged closer to the object side than the main aperture FS, or it can be arranged closer to the image side than the main aperture FS. The number of sub-apertures that meet the various conditional expressions configured in an optical system can be set arbitrarily. The radius of curvature, surface spacing, refractive index, Abbe number and aspheric coefficient of each lens are not limited to the values ​​shown in the above examples, and other values ​​can be adopted.

[0219] Furthermore, the imaging device according to the embodiment of the present invention is not limited to the above-mentioned example, and may be various types of cameras other than mirrorless cameras, film cameras, video cameras, movie cameras, and surveillance cameras.

[0220] The following additional notes are further disclosed with respect to the above-mentioned embodiments and examples.

[0221] [Supplementary Item 1]

[0222] An optical system comprising:

[0223] The first aperture with variable opening diameter;

[0224] three or more lenses including positive lenses and negative lenses arranged on the object side of the first aperture; and

[0225] The second aperture with a fixed opening diameter,

[0226] Let the distance on the optical axis from the first aperture to the second aperture be Dst, let the focal length of the optical system be f, and

[0227] When the optical system is a variable magnification optical system, Dst and f are set to the values ​​in the variable magnification state when the height of the axial marginal light from the optical axis reaches the maximum at the position of the second aperture.

[0228] The optical system satisfies the conditional equation (1) represented by the following equation:

[0229] 0.005<|Dst| / f<2 (1).

[0230] [Supplementary Item 2]

[0231] An optical system according to supplementary item 1, wherein:

[0232] When the opening diameter of the first aperture in the open state is φF,

[0233] The opening diameter of the second aperture is φS, and

[0234] When the optical system is a variable magnification optical system, φF and φS are set to values ​​in a variable magnification state when the height of the axial marginal light from the optical axis reaches the maximum at the position of the second aperture.

[0235] The optical system satisfies the conditional equation (2) represented by the following equation:

[0236] 0.3<φS / φF<2.5 (2).

[0237] [Supplementary item 3]

[0238] An optical system according to claim 1 or 2, wherein:

[0239] The convex lens surface in contact with the air is located within the opening of the second aperture.

[0240] The distance on the optical axis from the intersection of the lens surface and the optical axis to the second aperture where the lens surface is located in the opening is defined as Dp,

[0241] Regarding Dp, with the intersection point as a reference, the sign of the distance on the image side is set to positive, the sign of the distance on the object side is set to negative, and

[0242] When the paraxial curvature radius of the lens surface is set to Rp,

[0243] The optical system satisfies the conditional equation (3) represented by the following equation:

[0244] 0<Dp / Rp<0.4 (3).

[0245] [Supplementary Item 4]

[0246] An optical system according to any one of supplementary items 1 to 3, wherein:

[0247] The convex lens surface in contact with the air is located within the opening of the second aperture.

[0248] The distance on the optical axis from the intersection of the lens surface and the optical axis to the second aperture where the lens surface is located in the opening is defined as Dp,

[0249] Regarding Dp, with the intersection point as a reference, the sign of the distance on the image side is set to positive, and the sign of the distance on the object side is set to negative.

[0250] The paraxial curvature radius of the lens surface is set to Rp, and

[0251] When the effective diameter of the lens surface is φEp,

[0252] The optical system satisfies the conditional equation (4) represented by the following equation:

[0253] 0.7<{Rp-Rp×(1-(φEp / 2) 2 / Rp 2 ) 1 / 2} / Dp<1.5 (4).

[0254] [Supplementary Item 5]

[0255] An optical system according to any one of notes 1 to 4, wherein:

[0256] The concave lens surface in contact with the air is located near the second aperture.

[0257] The distance on the optical axis from the intersection of the lens surface and the optical axis to the second aperture is Dn,

[0258] Regarding Dn, with the intersection point as a reference, the sign of the distance on the image side is set to positive, and the sign of the distance on the object side is set to negative.

[0259] The paraxial curvature radius of the lens surface is set to Rn,

[0260] When there are two concave lens surfaces in contact with air located near the second aperture, the values ​​of the lens surface having an optically effective surface diameter closer to the aperture diameter of the second aperture are used for Dn and Rn, and

[0261] When the optical system is a variable magnification optical system, Dn is set to a value in a variable magnification state when the height of the axial marginal light from the optical axis reaches the maximum at the position of the second aperture.

[0262] The optical system satisfies the conditional equation (5) represented by the following equation:

[0263] 0<Dn / Rn<0.4 (5).

[0264] [Supplementary Item 6]

[0265] An optical system according to any one of notes 1 to 5, wherein:

[0266] The concave lens surface in contact with the air is located near the second aperture.

[0267] The distance on the optical axis from the intersection of the lens surface and the optical axis to the second aperture is Dn,

[0268] Regarding Dn, with the intersection point as a reference, the sign of the distance on the image side is set to positive, and the sign of the distance on the object side is set to negative.

[0269] The paraxial curvature radius of the lens surface is set to Rn,

[0270] The effective diameter of the lens surface is φEn,

[0271] When there are two concave lens surfaces in contact with air located near the second aperture, the values ​​of the lens surface having an optically effective surface diameter closer to the opening diameter of the second aperture are used for Dn, Rn, and φEn, and

[0272] When the optical system is a variable magnification optical system, Dn is set to a value in a variable magnification state when the height of the axial marginal light from the optical axis reaches the maximum at the position of the second aperture.

[0273] The optical system satisfies the conditional equation (6) represented by the following equation:

[0274] 0.5<{Rn-Rn×(1-(φEn / 2) 2 / Rn 2 ) 1 / 2} / Dn<1.2 (6).

[0275] [Supplementary Item 7]

[0276] An optical system according to any one of supplementary items 1 to 6, wherein:

[0277] The height of the principal ray with the maximum image height at the position of the second aperture from the optical axis is hp,

[0278] The height of the on-axis marginal ray from the optical axis at the position of the second aperture is hm, and

[0279] When the optical system is a variable-power optical system, hp and hm are set to values ​​in a variable-power state when the height of the axial marginal light from the optical axis reaches the maximum at the position of the second aperture.

[0280] The optical system satisfies the conditional equation (7) represented by the following equation:

[0281] 0<|hp| / hm<1 (7).

[0282] [Supplementary Item 8]

[0283] An optical system according to any one of notes 1 to 7, wherein:

[0284] The sum of the distance on the optical axis from the lens surface of the optical system closest to the object side to the lens surface of the optical system closest to the image side and the back focus in the air conversion distance of the optical system is TL,

[0285] The height of the principal ray of the maximum image height at the position of the second aperture from the optical axis is hp,

[0286] The height of the on-axis marginal ray from the optical axis at the position of the second aperture is hm, and

[0287] When the optical system is a variable-power optical system, Dst, TL, hp and hm are set to the values ​​in the variable-power state when the height of the on-axis marginal light from the optical axis reaches the maximum at the position of the second aperture.

[0288] The optical system satisfies the conditional equation (8) represented by the following equation:

[0289] 0.05<(|Dst| / TL) / (|hp| / hm)<1.8 (8).

[0290] [Supplementary Item 9]

[0291] An optical system according to any one of notes 1 to 8, wherein:

[0292] When one lens component is a single lens or a cemented lens, the composite focal length of all lens components on the object side of the second aperture is fs, and

[0293] When the optical system is a variable magnification optical system, f and fs are set to values ​​in a variable magnification state when the height of the axial marginal light from the optical axis reaches the maximum at the position of the second aperture.

[0294] The optical system satisfies the conditional equation (9) represented by the following equation:

[0295] -5<f / fs<5 (9).

[0296] [Supplementary Item 10]

[0297] An optical system according to any one of notes 1 to 9, wherein:

[0298] During focusing, the second aperture moves integrally with at least one lens of the optical system, or during focusing, the second aperture is integrally fixed with at least one lens of the optical system relative to the image plane.

[0299] When the optical system is a variable power optical system, the second aperture moves integrally with at least one lens of the optical system during variable power, or the second aperture is integrally fixed relative to an image plane with at least one lens of the optical system during variable power.

[0300] [Supplementary Note 11]

[0301] An optical system according to any one of notes 1 to 10, wherein:

[0302] The first aperture is an aperture for determining the F value.

[0303] [Supplementary Item 12]

[0304] An imaging device comprising the optical system according to any one of Supplementary Items 1 to 11.

[0305] All documents, patent applications, and technical standards described in this specification are incorporated herein by reference to the same extent as if each individual document, patent application, or technical standard were specifically and individually described as being incorporated by reference.

Claims

1. An optical system, comprising: The first aperture with variable opening diameter; three or more lenses including positive lenses and negative lenses arranged on the object side of the first aperture; and The second aperture with a fixed opening diameter, The distance on the optical axis from the first aperture to the second aperture is Dst, Let the focal length of the optical system be f, and When the optical system is a variable magnification optical system, Dst and f are set to the values ​​in the variable magnification state when the height of the axial marginal light from the optical axis reaches the maximum at the position of the second aperture. The optical system satisfies the conditional equation (1) represented by the following equation: 0.005<|Dst| / f<2 (1).

2. The optical system according to claim 1, wherein: When the opening diameter of the first aperture in the open state is φF, The opening diameter of the second aperture is φS, and When the optical system is a variable magnification optical system, φF and φS are set to values ​​in a variable magnification state when the height of the axial marginal light from the optical axis reaches the maximum at the position of the second aperture. The optical system satisfies the conditional equation (2) represented by the following equation: 0.3<φS / φF<2.5 (2).

3. The optical system according to claim 1, wherein: The convex lens surface in contact with the air is located within the opening of the second aperture. The distance on the optical axis from the intersection of the lens surface and the optical axis to the second aperture where the lens surface is located in the opening is defined as Dp, Regarding Dp, with the intersection point as a reference, the sign of the distance on the image side is set to positive, the sign of the distance on the object side is set to negative, and When the paraxial curvature radius of the lens surface is set to Rp, The optical system satisfies the conditional equation (3) represented by the following equation: 0<Dp / Rp<0.4 (3).

4. The optical system according to claim 1, wherein: The convex lens surface in contact with the air is located within the opening of the second aperture. The distance on the optical axis from the intersection of the lens surface and the optical axis to the second aperture where the lens surface is located in the opening is defined as Dp, Regarding Dp, with the intersection point as a reference, the sign of the distance on the image side is set to positive, and the sign of the distance on the object side is set to negative. The paraxial curvature radius of the lens surface is set to Rp, and When the effective diameter of the lens surface is φEp, The optical system satisfies the conditional equation (4) represented by the following equation: 0.7<{Rp-Rp×(1-(φEp / 2) 2 / Rp 2 ) 1 / 2 } / Dp<1.5 (4)。 5. The optical system according to claim 1, wherein: The concave lens surface in contact with the air is located near the second aperture. The distance on the optical axis from the intersection of the lens surface and the optical axis to the second aperture is Dn, Regarding Dn, with the intersection point as a reference, the sign of the distance on the image side is set to positive, and the sign of the distance on the object side is set to negative. The paraxial curvature radius of the lens surface is set to Rn, When there are two concave lens surfaces in contact with air located near the second aperture, the values ​​of the lens surface having an optically effective surface diameter closer to the aperture diameter of the second aperture are used for Dn and Rn, and When the optical system is a variable magnification optical system, Dn is set to a value in a variable magnification state when the height of the axial marginal light from the optical axis reaches the maximum at the position of the second aperture. The optical system satisfies the conditional equation (5) represented by the following equation: 0 <Dn / Rn<0.4 (5)。 6. The optical system according to claim 1, wherein: The concave lens surface in contact with the air is located near the second aperture. The distance on the optical axis from the intersection of the lens surface and the optical axis to the second aperture is Dn, Regarding Dn, with the intersection point as a reference, the sign of the distance on the image side is set to positive, and the sign of the distance on the object side is set to negative. The paraxial curvature radius of the lens surface is set to Rn, The effective diameter of the lens surface is φEn, When there are two concave lens surfaces in contact with air located near the second aperture, the values ​​of the lens surface having an optically effective surface diameter closer to the opening diameter of the second aperture are used for Dn, Rn, and φEn, and When the optical system is a variable magnification optical system, Dn is set to a value in a variable magnification state when the height of the axial marginal light from the optical axis reaches the maximum at the position of the second aperture. The optical system satisfies the conditional equation (6) represented by the following equation: 0.5<{Rn-Rn×(1-(φEn / 2) 2 / Rn 2 ) 1 / 2 } / Dn<1.2 (6)。 7. The optical system according to claim 1, wherein: The height of the principal ray with the maximum image height at the position of the second aperture from the optical axis is hp, The height of the on-axis marginal ray from the optical axis at the position of the second aperture is hm, and When the optical system is a variable-power optical system, hp and hm are set to values ​​in a variable-power state when the height of the axial marginal light from the optical axis reaches the maximum at the position of the second aperture. The optical system satisfies the conditional equation (7) represented by the following equation: 0<|hp| / hm<1 (7).

8. The optical system according to claim 1, wherein: The sum of the distance on the optical axis from the lens surface of the optical system closest to the object side to the lens surface of the optical system closest to the image side and the back focus in the air conversion distance of the optical system is TL, The height of the principal ray of the maximum image height at the position of the second aperture from the optical axis is hp, The height of the on-axis marginal ray from the optical axis at the position of the second aperture is hm, and When the optical system is a variable-power optical system, Dst, TL, hp and hm are set to the values ​​in the variable-power state when the height of the on-axis marginal light from the optical axis reaches the maximum at the position of the second aperture. The optical system satisfies the conditional equation (8) represented by the following equation: 0.05<(|Dst| / TL) / (|hp| / hm)<1.8 (8).

9. The optical system according to claim 1, wherein: When one lens component is made into a single lens or a cemented lens, The composite focal length of all lens components on the object side of the second aperture is fs, and When the optical system is a variable magnification optical system, f and fs are set to values ​​in a variable magnification state when the height of the axial marginal light from the optical axis reaches the maximum at the position of the second aperture. The optical system satisfies the conditional equation (9) represented by the following equation: -5 <f / fs<5 (9)。 10. The optical system according to claim 1, wherein: During focusing, the second aperture moves integrally with at least one lens of the optical system, or during focusing, the second aperture is integrally fixed with at least one lens of the optical system relative to the image plane. When the optical system is a variable power optical system, the second aperture moves integrally with at least one lens of the optical system during variable power, or the second aperture is integrally fixed relative to an image plane with at least one lens of the optical system during variable power.

11. The optical system according to claim 2, wherein: The convex lens surface in contact with the air is located within the opening of the second aperture. The distance on the optical axis from the intersection of the lens surface and the optical axis to the second aperture where the lens surface is located in the opening is defined as Dp, Regarding Dp, with the intersection point as a reference, the sign of the distance on the image side is set to positive, the sign of the distance on the object side is set to negative, and When the paraxial curvature radius of the lens surface is set to Rp, The optical system satisfies the conditional equation (3) represented by the following equation: 0 <Dp / Rp<0.4 (3)。 12. The optical system according to claim 2, wherein: The convex lens surface in contact with the air is located within the opening of the second aperture. The distance on the optical axis from the intersection of the lens surface and the optical axis to the second aperture where the lens surface is located in the opening is defined as Dp, Regarding Dp, with the intersection point as a reference, the sign of the distance on the image side is set to positive, and the sign of the distance on the object side is set to negative. The paraxial curvature radius of the lens surface is set to Rp, and When the effective diameter of the lens surface is φEp, The optical system satisfies the conditional equation (4) represented by the following equation: 0.7<{Rp-Rp×(1-(φEp / 2) 2 / Rp 2 ) 1 / 2 } / Dp<1.5 (4)。 13. The optical system according to claim 2, wherein: The concave lens surface in contact with the air is located near the second aperture. The distance on the optical axis from the intersection of the lens surface and the optical axis to the second aperture is Dn, Regarding Dn, with the intersection point as a reference, the sign of the distance on the image side is set to positive, and the sign of the distance on the object side is set to negative. The paraxial curvature radius of the lens surface is set to Rn, When there are two concave lens surfaces in contact with air located near the second aperture, the values ​​of the lens surface having an optically effective surface diameter closer to the aperture diameter of the second aperture are used for Dn and Rn, and When the optical system is a variable magnification optical system, Dn is set to a value in a variable magnification state when the height of the axial marginal light from the optical axis reaches the maximum at the position of the second aperture. The optical system satisfies the conditional equation (5) represented by the following equation: 0 <Dn / Rn<0.4 (5)。 14. The optical system according to claim 2, wherein: The concave lens surface in contact with the air is located near the second aperture. The distance on the optical axis from the intersection of the lens surface and the optical axis to the second aperture is Dn, Regarding Dn, with the intersection point as a reference, the sign of the distance on the image side is set to positive, and the sign of the distance on the object side is set to negative. The paraxial curvature radius of the lens surface is set to Rn, The effective diameter of the lens surface is φEn, When there are two concave lens surfaces in contact with air located near the second aperture, the values ​​of the lens surface having an optically effective surface diameter closer to the opening diameter of the second aperture are used for Dn, Rn, and φEn, and When the optical system is a zoom optical system, Dn is set to a value in a zoom state when the height of the axial marginal light from the optical axis reaches the maximum at the position of the second aperture. The optical system satisfies the conditional equation (6) represented by the following equation: 0.5<{Rn-Rn×(1-(φEn / 2) 2 / Rn 2 ) 1 / 2 } / Dn<1.2 (6)。 15. The optical system according to claim 2, wherein: The height of the principal ray with the maximum image height at the position of the second aperture from the optical axis is hp, The height of the on-axis marginal ray from the optical axis at the position of the second aperture is hm, and When the optical system is a variable-power optical system, hp and hm are set to values ​​in a variable-power state when the height of the axial marginal light from the optical axis reaches the maximum at the position of the second aperture. The optical system satisfies the conditional equation (7) represented by the following equation: 0<|hp| / hm<1 (7).

16. The optical system of claim 2, wherein: The sum of the distance on the optical axis from the lens surface of the optical system closest to the object side to the lens surface of the optical system closest to the image side and the back focus in the air conversion distance of the optical system is TL, The height of the principal ray of the maximum image height at the position of the second aperture from the optical axis is hp, The height of the on-axis marginal ray from the optical axis at the position of the second aperture is hm, and When the optical system is a variable-power optical system, Dst, TL, hp and hm are set to the values ​​in the variable-power state when the height of the on-axis marginal light from the optical axis reaches the maximum at the position of the second aperture. The optical system satisfies the conditional equation (8) represented by the following equation: 0.05<(|Dst| / TL) / (|hp| / hm)<1.8 (8).

17. The optical system according to claim 2, wherein: When one lens component is a single lens or a cemented lens, the composite focal length of all lens components on the object side of the second aperture is fs, and When the optical system is a variable magnification optical system, f and fs are set to values ​​in a variable magnification state when the height of the axial marginal light from the optical axis reaches the maximum at the position of the second aperture. The optical system satisfies the conditional equation (9) represented by the following equation: -5 <f / fs<5 (9)。 18. The optical system of claim 2, wherein: During focusing, the second aperture moves integrally with at least one lens of the optical system, or during focusing, the second aperture is integrally fixed with at least one lens of the optical system relative to the image plane. When the optical system is a variable power optical system, the second aperture moves integrally with at least one lens of the optical system during variable power, or the second aperture is integrally fixed relative to an image plane with at least one lens of the optical system during variable power.

19. The optical system of claim 1, wherein: The first aperture is an aperture for determining the F value. 20 . An imaging device comprising the optical system according to claim 1 .

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