Imaging optical system and imaging device

Abstract

To make it possible to excellently correct various aberrations while achieving miniaturization and reduction in weight by using an aspherical lens properly.SOLUTION: An image formation optical system of the present disclosure comprises: a plurality of lenses that includes an aspherical lens; and an aperture stop. Let a lens diameter of the aspherical lens be y, and a sag amount of an aspherical surface of the aspherical lens be x, and when a sag amount at a point where dx / dy=0 (dx / dy: a primary differential of the sag amount x by the lens dimeter y) in the aspherical surface of the aspherical lens is x1, x2, and ...xn, and when a sag amount in a position where the lens diameter y is a light beam effective radius is xn+1, and when a maximum value of |xi-xi-1|(i=2, ...n+1) is xm, the image formation optical system satisfies following conditional expressions. 0.01<xm / Dga<0.50.....(1), and n≥2.....(2) where Dga is a light beam effective radius on the aspherical surface of the aspherical lens.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This disclosure relates to an imaging optical system and an imaging device. [Background technology]

[0002] In recent years, imaging devices such as digital cameras have seen advancements in image sensor size and image quality. Consequently, high performance is required of the imaging lenses used in these devices, and strict correction of various aberrations is becoming increasingly necessary. On the other hand, with the advancement of shorter flange back distances in mirrorless cameras and the like, there is also a demand for miniaturization of optical systems. In response to these demands, various imaging optical systems using aspherical lenses have been proposed (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2016-139087 [Patent Document 2] Japanese Patent Publication No. 2004-29832 [Overview of the project] [Problems that the invention aims to solve]

[0004] In imaging optical systems, when attempting to achieve miniaturization and weight reduction while maintaining high resolution even at the edges, there is a tendency for astigmatism, field curvature, coma aberration, and sagittal coma flare to worsen.

[0005] It is desirable to provide an imaging optical system that can achieve miniaturization and weight reduction while effectively correcting various aberrations by appropriately using aspherical lenses, and an imaging device equipped with such an imaging optical system. [Means for solving the problem]

[0006] The first imaging optical system according to an embodiment of the present disclosure includes a plurality of lenses including an aspherical lens and an aperture stop. The system comprises multiple lenses, including at least six lenses with refractive power. Let the lens diameter of the aspherical lens be y, the sag amount of the aspherical surface of the aspherical lens be x, and the sag amounts at the points where dx / dy = 0 (dx / dy: the first derivative of the sag amount x with respect to the lens diameter y) on the aspherical surface of the aspherical lens be x1, x2,... xn, and the sag amount at the position where the lens diameter y becomes the effective radius of the light ray be x n+1 , |x i -x i-1 | (i = 2,... n + 1) is xm, and it is an imaging optical system that satisfies the following conditional expressions. 0.01 < xm / Dga < 0.50......(1) n ≥ 2......(2) 1.644 < 0.0024 * Vga + Nga < 2.400......(3) 1.893 < 0.0093 * Vga + Nga < 3.000......(4) 0.3 < Lexp / Lgaf < 50.0......(5) 0.01≦hga 2 *hga^ 2 / hi 4 <10.00 ……(10) 0.60 <BF / fa<5.00 ……(12)’ However, Dga: The effective radius of the light ray on the aspherical surface of the aspherical lens Vga: The Abbe number of the aspherical lens Nga: The refractive index of the aspherical lens Lgaf: The distance from the object-side surface of the aspherical lens to the image plane Lexp: The distance from the exit pupil of the optical system to the image plane hga: Height of the pupillary meriaxial ray when passing through the object-side surface of the aspherical lens. hga^: Height of the pupillary paraxial ray when passing through the object-side surface of the aspherical lens. hi: Radius of the aperture diameter of the optical system BF: Back focus (the distance from the image-plane side of the lens closest to the image plane in an imaging optical system to the image plane itself). fa: Focal length of the entire system Let it be so.

[0007] The second imaging optical system according to an embodiment of the present disclosure includes a plurality of lenses including an aspherical lens and an aperture stop. Let the lens diameter of the aspherical lens be y, the sag amount of the aspherical surface of the aspherical lens be x, and the sag amounts at the points where dx / dy = 0 (dx / dy: the first derivative of the sag amount x with respect to the lens diameter y) on the aspherical surface of the aspherical lens be x1, x2,... xn, and the sag amount at the position where the lens diameter y becomes the effective radius of the light beam be x n+1 , |x i -x i-1 | (i = 2,... n + 1) is an imaging optical system that satisfies the following conditional expressions when the maximum value is xm. 0.01 < xm / Dga < 0.50......(1) n ≧ 2......(2) 1.644 < 0.0024 * Vga + Nga < 2.400......(3) 1.893 < 0.0093 * Vga + Nga < 3.000......(4) 0.05 < Lenp / Lgae < 50.00......(6) However, Dga: The effective radius of the light beam on the aspherical surface of the aspherical lens Vga: The Abbe number of the aspherical lens Nga: The refractive index of the aspherical lens Lgae: The distance from the object-side surface of the lens closest to the object among the plurality of lenses to the aspherical lens Lenp: The distance from the object-side surface of the lens closest to the object among the plurality of lenses to the exit pupil of the optical system is defined as such.

[0008] The first imaging device according to an embodiment of the present disclosure includes an imaging optical system and an imaging element that outputs an imaging signal corresponding to the optical image formed by the imaging optical system, and the imaging optical system is configured by the first imaging optical system according to an embodiment of the present disclosure described above.

[0009] The second imaging device according to an embodiment of the present disclosure includes an imaging optical system and an imaging element that outputs an imaging signal corresponding to the optical image formed by the imaging optical system, and the imaging optical system is configured by the second imaging optical system according to an embodiment of the present disclosure described above.

[0010] In the first and second imaging optical systems or first and second imaging devices according to one embodiment of the present disclosure, the shape and position of the aspherical lenses are optimized to enable good correction of various aberrations while achieving miniaturization and weight reduction. [Brief explanation of the drawing]

[0011] [Figure 1] This is a lens cross-sectional view showing a first configuration example (Example 1) of an imaging optical system according to one embodiment of the present disclosure. [Figure 2] This is an aberration diagram showing the longitudinal aberration of the imaging optical system according to Example 1 when it is in focus at infinity. [Figure 3] This is an aberration diagram showing the lateral aberration of the imaging optical system according to Example 1 when it is in focus at infinity. [Figure 4] This is a lens cross-sectional view showing a second configuration example (Example 2) of an imaging optical system according to one embodiment. [Figure 5] This is an aberration diagram showing the longitudinal aberration of the imaging optical system according to Example 2 when it is in focus at infinity. [Figure 6] This is an aberration diagram showing the transverse aberration of the imaging optical system according to Example 2 when it is in focus at infinity. [Figure 7] This is a lens cross-sectional view showing a third configuration example (Example 3) of an imaging optical system according to one embodiment. [Figure 8] This is an aberration diagram showing the longitudinal aberration of the imaging optical system according to Example 3 when it is in focus at infinity. [Figure 9] This is an aberration diagram showing the lateral aberration of the imaging optical system according to Example 3 when it is in focus at infinity. [Figure 10] This is a lens cross-sectional view showing a fourth configuration example (Example 4) of an imaging optical system according to one embodiment. [Figure 11] This is an aberration diagram showing the longitudinal aberration of the imaging optical system according to Example 4 at the wide-angle end and when focused at infinity. [Figure 12] This is an aberration diagram showing the longitudinal aberration of the imaging optical system according to Example 4 at the telephoto end and when focused at infinity. [Figure 13]This is an aberration diagram showing the lateral aberration of the imaging optical system according to Example 4 at the wide-angle end and when focused at infinity. [Figure 14] This is an aberration diagram showing the lateral aberration of the imaging optical system according to Example 4 at the telephoto end and when focused at infinity. [Figure 15] This is a lens cross-sectional view showing a fifth configuration example (Example 5) of an imaging optical system according to one embodiment. [Figure 16] This is an aberration diagram showing the longitudinal aberration of the imaging optical system according to Example 5 when it is in focus at infinity. [Figure 17] This is an aberration diagram showing the lateral aberration of the imaging optical system according to Example 5 when it is in focus at infinity. [Figure 18] This is a lens cross-sectional view showing a sixth configuration example (Example 6) of an imaging optical system according to one embodiment. [Figure 19] This is an aberration diagram showing the longitudinal aberration of the imaging optical system according to Example 6 when it is in focus at infinity. [Figure 20] This is an aberration diagram showing the transverse aberration of the imaging optical system according to Example 6 when it is in focus at infinity. [Figure 21] This is a lens cross-sectional view showing a seventh configuration example (Example 7) of an imaging optical system according to one embodiment. [Figure 22] This is an aberration diagram showing the longitudinal aberration of the imaging optical system according to Example 7 when it is in focus at infinity. [Figure 23] This is an aberration diagram showing the lateral aberration of the imaging optical system according to Example 7 when it is in focus at infinity. [Figure 24] This is an explanatory diagram illustrating the general sag amount of aspherical lenses. [Figure 25] This is an explanatory diagram illustrating the overview of the pupil's paraxial ray and the pupil's paraaxial ray. [Figure 26] This is a block diagram showing an example configuration of an imaging device. [Figure 27] This block diagram shows an example of a schematic configuration of a vehicle control system. [Figure 28] This is an explanatory diagram showing an example of the installation location of the external information detection unit and the imaging unit. [Figure 29] This figure shows an example of a schematic configuration of an endoscope system. [Figure 30] Figure 29 shows an example of the functional configuration of the camera and CCU (blockchain). [Figure 31] This figure shows an example of a schematic configuration of a microsurgical system. [Modes for carrying out the invention]

[0012] The embodiments of this disclosure will be described in detail below with reference to the drawings. The description will be given in the following order. 0. Comparative Example 1. Basic lens configuration 2. Action and Effects 3. Examples of application to imaging devices 4. Numerical Examples of Lenses 5. Application Examples 6. Other Embodiments

[0013] <0. Comparative Example> Glass aspherical lenses face significant constraints on manufacturability regarding the reversal of aspherical curvature and local curvature. Therefore, when using glass aspherical lenses in a typical lens system, the aspherical shape is limited, making it difficult to achieve miniaturization and weight reduction while effectively correcting various aberrations, particularly distortion, field curvature, and coma. In contrast, plastic aspherical lenses differ from glass aspherical lenses in their molding method, resulting in fewer constraints on aspherical curvature reversal and local curvature. However, plastic aspherical lenses suffer from weaker environmental resistance, such as greater refractive index changes due to temperature fluctuations.

[0014] Patent Document 1 (Japanese Patent Publication No. 2016-139087) proposes a large-aperture wide-angle prime lens as an imaging optical system. However, due to the various aberrations that occur with wide-angle lenses, it is difficult to adequately correct astigmatism and coma aberration at high image heights.

[0015] Furthermore, Patent Document 2 (Japanese Patent Publication No. 2004-29832) proposes a zoom lens using a plastic aspherical lens as an imaging optical system. However, because it is made of plastic, it is necessary to consider temperature changes in its shape, which limits the degree of freedom in the aspherical shape. As a result, it is difficult to adequately correct astigmatism and field curvature.

[0016] <1. Basic Lens Configuration> One embodiment of this disclosure relates to an imaging optical system optimized for digital still cameras and digital mirrorless cameras, and to an optical instrument having such an imaging optical system. In particular, it relates to a compact and high-performance imaging optical system capable of performing good aberration correction by effectively using aspherical surfaces, and to an imaging device equipped with such an imaging optical system.

[0017] Figure 1 shows a first configuration example of an imaging optical system according to one embodiment of the present disclosure, and corresponds to the configuration of Example 1 described later. Figure 4 shows a second configuration example of an imaging optical system according to one embodiment, and corresponds to the configuration of Example 2 described later. Figure 7 shows a third configuration example of an imaging optical system according to one embodiment, and corresponds to the configuration of Example 3 described later. Figure 10 shows a fourth configuration example of an imaging optical system according to one embodiment, and corresponds to the configuration of Example 4 described later. Figure 15 shows a fifth configuration example of an imaging optical system according to one embodiment, and corresponds to the configuration of Example 5 described later. Figure 18 shows a sixth configuration example of an imaging optical system according to one embodiment, and corresponds to the configuration of Example 6 described later. Figure 21 shows a seventh configuration example of an imaging optical system according to one embodiment, and corresponds to the configuration of Example 7 described later.

[0018] In Figure 1, etc., Z1 indicates the optical axis. Between the imaging optical systems 1 to 7 according to the first to seventh configuration examples and the image plane, optical elements such as cover glass for protecting the image sensor may be placed. In addition to cover glass, various optical filters such as low-pass filters and infrared cut filters may be placed as optical elements.

[0019] Hereinafter, the configuration of the imaging optical system according to one embodiment of the present disclosure will be described in correspondence with the imaging optical systems 1 to 7 shown in Figure 1 and other examples as appropriate, but the technology of the present disclosure is not limited to the illustrated configuration examples.

[0020] An imaging optical system according to one embodiment comprises a plurality of lenses, including an aspherical lens GA, and an aperture diaphragm St.

[0021] In one embodiment of the imaging optical system, the lens diameter of the aspherical lens GA is y, and the sag amount of the aspherical surface of the aspherical lens GA is x. The sag amounts at the points on the aspherical surface of the aspherical lens GA where dx / dy = 0 (dx / dy: the first derivative of the sag amount x due to the lens diameter y) are x1, x2, ..., xn, and the sag amount at the position where the lens diameter y is the effective radius of light is x. n+1 , |x i -x i-1 When xm is the maximum value of |(i=2,…n+1), the following condition is satisfied. 0.01 <xm / Dga<0.50 ……(1) n≧2 ……(2) 1.644<0.0024*Vga+Nga<2.400 ……(3) 1.893<0.0093*Vga+Nga<3.000 ……(4) 0.3 <Lexp / Lgaf<50.0 ……(5) however, Dga: Effective ray radius at the aspherical surface of the aspherical lens GA Vga: Abbe number of aspherical lens GA Nga: Refractive index of aspherical lens GA Lgaf: Distance from the object-side surface to the image plane of an aspherical lens (GA). Lexp: Distance from the exit pupil to the image plane of the optical system. Let's assume that.

[0022] Furthermore, the imaging optical system according to one embodiment may be configured to satisfy the following conditional equation. 0.01 <xm / Dga<0.50 ……n≧2 n≧2 ……(2) 1.644<0.0024*Vga+Nga<2.400 ……(3) 1.893<0.0093*Vga+Nga<3.000 ……(4) 0.05 <Lenp / Lgae<50.00 ……(6) however, Dga: Effective ray radius at the aspherical surface of the aspherical lens GA Vga: Abbe number of aspherical lens GA Nga: Refractive index of aspherical lens GA Lgae: The distance from the object-side surface of the lens closest to the object among multiple lenses to the aspherical lens GA. Lensp: The distance from the object-side surface of the lens closest to the object among multiple lenses to the exit pupil of the optical system. Let's assume that.

[0023] Figure 24 shows an overview of the sag amount x of an aspherical lens GA. In an aspherical lens, the point where dx / dy = 0 means an inflection point where the shape of the surface changes from convex to concave, or from concave to convex. Figure 24 shows an example with two inflection points (n=2). The sag amount x at the position where the lens diameter y is the effective ray radius. n+1 It becomes x3.

[0024] Furthermore, the imaging optical system according to one embodiment may also satisfy predetermined conditional formulas, etc., as described later.

[0025] In the case where the imaging optical system according to one embodiment is a variable magnification optical system (zoom lens), the conditional values ​​in each of the above conditional formulas shall be the values ​​at the wide-angle end. The same applies to the conditional formulas described later.

[0026] <2. Action and Effects> Next, the operation and effects of an imaging optical system according to one embodiment of the present disclosure will be described. In addition, a more preferred configuration of the imaging optical system according to one embodiment of the present disclosure, and its operation and effects will be described. Furthermore, the effects described herein are merely illustrative and not limited to those described herein, and other effects may also occur.

[0027] According to one embodiment of the imaging optical system, by optimizing the shape and position of the aspherical lens GA and using the aspherical lens GA appropriately, it is possible to achieve miniaturization and weight reduction while effectively correcting various aberrations (especially distortion, field curvature, and coma aberration).

[0028] Furthermore, the imaging optical system according to one embodiment satisfies the above-mentioned conditions (1) and (2), thereby creating a shape difference between the central and peripheral parts of the aspherical lens GA with respect to the optical axis Z1. This makes it possible to effectively correct field curvature and coma aberration. If the values ​​fall below the lower limits of conditions (1) and (2), it becomes impossible to create a shape difference between the central and peripheral parts of the aspherical lens GA with respect to the optical axis Z1, making it difficult to correct field curvature and coma aberration. On the other hand, if the values ​​exceed the upper limit of condition (1), it becomes necessary to give the aspherical lens GA a large amount of sag, making it difficult to stably manufacture lenses with high shape accuracy.

[0029] Furthermore, the lower limit of condition (1) may be set to 0.03. This allows for a greater difference in shape between the central and peripheral parts with respect to the optical axis Z1 in the aspherical lens GA, thereby enabling better correction of field curvature and coma aberration. Alternatively, the upper limit of condition (1) may be set to 0.30. This reduces the amount of sag, allowing for more stable manufacturing of lenses with higher shape accuracy.

[0030] Furthermore, the lower limit of condition (1) may be set to 0.04. This allows for a greater difference in shape between the central and peripheral parts of the aspherical lens GA with respect to the optical axis Z1, thereby enabling better correction of field curvature and coma aberration. Alternatively, the upper limit of condition (1) may be set to 0.20. This allows for a further reduction in sag, enabling the more stable manufacture of lenses with even higher shape accuracy.

[0031] Furthermore, the imaging optical system according to one embodiment satisfies both the above-mentioned conditions (3) and (4), allowing the use of a glass material with a high refractive index for the aspherical lens GA. This makes it possible to give the aspherical lens GA a strong refractive power even with an aspherical shape with small curvature. If the value falls below the lower limit of either condition (3) or condition (4), the aspherical lens GA is required to have an aspherical shape with a larger curvature, which increases the eccentricity sensitivity of the aspherical lens GA and makes stable production difficult. On the other hand, if the value exceeds the upper limit of either condition (3) or condition (4), the specific gravity of glass material generally has a positive correlation with the refractive index, and the higher the specific gravity, the higher the refractive index tends to be. Therefore, the aspherical lens GA becomes heavier, making it difficult to miniaturize and lighten the optical system.

[0032] The lower limit of condition (3) may be set to 1.700. This allows the aspherical lens GA to have a stronger refractive power.

[0033] Figure 25 shows an overview of the pupil's paraxial ray and the pupil's paraaxial ray. The pupil's paraxial ray is a ray that enters the lens diameter of the imaging optical system at an angle to the optical axis Z1, passes through the intersection of the entrance pupil of the optical system and the optical axis Z1, and forms an image at the maximum image height. The pupil's paraaxial ray is a ray that enters the lens diameter of the imaging optical system at 0° (parallel) to the optical axis Z1, passes through the entrance pupil of the optical system, and forms an image on the optical axis. In Figure 25, the angle of incidence of the ray is measured from the optical axis Z1, with clockwise being positive and counterclockwise being negative. Also in Figure 25, the object is assumed to be on the left side of the optical system, and the ray entering the imaging optical system from the object side travels from left to right.

[0034] Generally, in an imaging optical system, as the exit pupil approaches the image plane, a difference arises between the height of the pupil's paraxial ray from the optical axis Z1 and the height of the pupil's paraxial ray from the optical axis Z1. Therefore, in an imaging optical system according to one embodiment, satisfying the above condition (5) makes it possible to effectively correct field curvature and coma aberration. If the value falls below the lower limit of condition (5), the exit pupil approaches the image plane too closely, increasing the angle of incidence to the image plane, resulting in significant vignetting and making it difficult to secure sufficient peripheral light. On the other hand, if the value exceeds the upper limit of condition (5), the aspherical lens GA approaches the image plane too closely, potentially causing interference between the image plane and the lens due to manufacturing tolerances.

[0035] Alternatively, the lower limit of condition (5) may be set to 1.0. This allows for greater ambient light to be secured.

[0036] Furthermore, the upper limit of condition (5) may be set to 16.0. This allows for a greater distance between the aspherical lens GA and the image plane, further reducing the sensitivity to manufacturing errors of the aspherical lens GA. Additionally, the upper limit of condition (5) may be set to 5.0. This allows for an even greater distance between the aspherical lens GA and the image plane, further reducing the sensitivity to manufacturing errors of the aspherical lens GA.

[0037] Furthermore, the imaging optical system according to one embodiment, by satisfying the above condition (6), can create a difference between the height of the pupil's paraxial ray passing through the aspherical lens GA and the height of the pupil's paraxial ray, thereby enabling good correction of field curvature and coma aberration. If the value falls below the lower limit of condition (6), the aspherical lens GA will be too close to the image plane, potentially causing interference between the image plane and the lens due to manufacturing errors. On the other hand, if the value exceeds the upper limit of condition (6), the aspherical lens GA will be closer to the object, increasing the diameter of the aspherical lens GA and making miniaturization and weight reduction difficult.

[0038] Alternatively, the lower limit of condition (6) may be set to 0.9. This allows for a greater distance between the aspherical lens GA and the image plane, thereby further reducing the sensitivity to manufacturing errors of the aspherical lens GA.

[0039] Furthermore, the upper limit of condition (6) may be set to 16.0. This allows the diameter of the aspherical lens GA to be made smaller, enabling further miniaturization and weight reduction. Additionally, the upper limit of condition (6) may be set to 2.0. This allows the diameter of the aspherical lens GA to be made even smaller, enabling further miniaturization and weight reduction.

[0040] Furthermore, the imaging optical system according to one embodiment may satisfy the following condition (7). 0.01<|DLga| / DLa<1.00 ……(7) however, DLga: Distance along the optical axis between the object-side surface of the aspherical lens GA and the aperture diaphragm St. DLa: The distance from the object-side surface of the lens closest to the object among multiple lenses to the image-side surface of the lens closest to the image plane among multiple lenses. Let's assume that.

[0041] By satisfying condition (7), the distance between the aspherical lens GA and the aperture diaphragm St can be appropriately set, thereby creating a difference between the height of the pupil's paraxial rays passing through the aspherical lens GA and the height of the pupil's paraxial rays. This makes it possible to effectively correct field curvature and coma aberration. If the value falls below the lower limit of condition (7), the pupil's paraxial rays and the pupil's paraxial rays passing through the aspherical lens GA pass closer to the optical axis Z1 in the aspherical lens GA, making it difficult to correct field curvature and distortion aberrations. On the other hand, if the value exceeds the upper limit of condition (7), there is either no lens on the object side of the aperture diaphragm St, or no lens on the image plane side of the aperture diaphragm St, making it difficult to properly correct aberrations.

[0042] Furthermore, the lower limit of conditional equation (7) may be set to 0.30. This allows for better correction of field curvature and distortion. Additionally, the lower limit of conditional equation (7) may be set to 0.40. This allows for even better correction of field curvature and distortion.

[0043] Furthermore, the imaging optical system according to one embodiment may satisfy the following condition (8). -20.0 <hga^ / hgf^≦1.0 ……(8) however, hga^: Height of the pupillary paraxial ray when passing through the aspherical lens GA. hgf^: The height of the pupil's paraxial ray when passing through the lens closest to the object among multiple lenses. Let's assume that.

[0044] By satisfying condition (8), aspherical lens GA can be produced stably. If the value falls below the lower limit of condition (8), the aspherical lens GA will become larger, making it difficult to produce it stably. On the other hand, the upper limit of condition (8) is when the aspherical lens GA and the lens closest to the object are identical, and therefore the upper limit will not be exceeded.

[0045] Furthermore, the lower limit of condition (8) may be set to -10.0. This allows for a smaller aspherical lens GA, thus enabling more stable production of the aspherical lens GA. Additionally, the lower limit of condition (8) may be set to 0.8. This allows the aspherical lens GA to be positioned closer to the object than the aperture diaphragm St, enabling better correction of field curvature and distortion aberrations.

[0046] Alternatively, the upper limit of condition (8) may be set to -0.4. This allows for further miniaturization of the aspherical lens GA.

[0047] Furthermore, the imaging optical system according to one embodiment may satisfy the following condition (9). -20.0 <hga^ / hgb^≦1.0 ……(9) however, hga^: Height of the pupillary paraxial ray when passing through the aspherical lens GA. hgb^: Height of the pupil's paraxial ray when passing through the lens closest to the image plane among multiple lenses. Let's assume that.

[0048] By satisfying condition (9), aspherical lenses GA can be produced stably.

[0049] Furthermore, the lower limit of condition (9) may be set to -4.0. This allows for further miniaturization of the aspherical lens GA, thereby enabling more stable production of the aspherical lens GA.

[0050] Alternatively, the upper limit of condition (9) may be set to 0.5. This allows the aspherical lens GA to be positioned closer to the object than the aperture diaphragm St, thereby providing better correction of field curvature and distortion. Furthermore, the upper limit of condition (9) may be set to -0.4. This allows the aspherical lens GA to be positioned closer to the object than the aperture diaphragm St, providing even better correction of field curvature and distortion.

[0051] Furthermore, the imaging optical system according to one embodiment may satisfy the following condition (10). 0.01≦hga 2 *hga^ 2 / hi 4 <10.00 ……(10) however, hga: Height of the paraaxial ray of the pupil when passing through the aspheric lens GA. hga^: Height of the pupillary paraxial ray when passing through the aspherical lens GA. hi: Radius of the aperture diameter of the optical system Let's assume that.

[0052] By satisfying condition (10), the aspherical lens GA can have appropriate sensitivity to field curvature and coma aberration, and can effectively correct field curvature and coma aberration. If the value falls below the lower limit of condition (10), the height hga of the pupil's paraxial ray passing through the aspherical lens GA and the height hga^ of the pupil's paraxial ray passing through the aspherical lens GA become too low, making it difficult for the aspherical lens GA to have the sensitivity to correct field curvature and coma aberration. On the other hand, if the value exceeds the upper limit of condition (10), the height hga^ of the pupil's paraxial ray passing through the aspherical lens GA becomes too high, increasing the diameter of the aspherical lens GA and making the entire optical system larger, thus making miniaturization difficult.

[0053] The lower limit of condition (10) may be set to 0.1. This allows the aspherical lens GA to have more appropriate sensitivity to field curvature and coma aberration. The upper limit of condition (10) may also be set to 3.00. This allows the diameter of the aspherical lens GA to be made smaller.

[0054] Furthermore, the imaging optical system according to one embodiment may satisfy the following condition (11). -4.0 <DLga / fa<5.0 ……(11) however, DLga: Distance along the optical axis between the object-side surface of the aspherical lens GA and the aperture diaphragm St. fa: Focal length of the entire system Let's assume that.

[0055] As the overall focal length fa decreases, the exit pupil moves closer to the image plane, and the angle of incidence of light rays to the image plane decreases. In general, as the exit pupil moves closer to the image plane, a difference arises between the height of the pupil's paraxial ray from the optical axis Z1 and the height of the pupil's paraxial ray from the optical axis Z1. Therefore, by satisfying condition (11), the pupil's paraxial ray and the pupil's paraxial ray can be corrected well in the aspherical lens GA. If the value falls below the lower limit of condition (11), the distance of the aspherical lens GA to the aperture diaphragm St becomes long, making it difficult to miniaturize the optical system. On the other hand, if the value exceeds the upper limit of condition (11), the aspherical lens GA moves too close to the image plane, increasing the eccentricity sensitivity of the aspherical lens GA and making it difficult to stably produce the aspherical lens GA.

[0056] The lower limit of conditional equation (11) may be set to 0.9. This allows the aspherical lens GA to be positioned on the image plane side of the exit pupil, and a sufficient distance from the exit pupil to the aspherical lens GA to be secured, thereby effectively correcting field curvature and distortion aberrations.

[0057] Furthermore, in the imaging optical system according to one embodiment, the configuration may include at least six lenses as the plurality of lenses. In order to provide a large-aperture and high-performance optical system, it is necessary to correct aberrations well, but if the number of lenses is less than six, it becomes difficult to correct aberrations well. By using a configuration with at least seven lenses, aberrations can be corrected more effectively. Furthermore, by using a configuration with at least eight lenses, aberrations can be corrected even more effectively.

[0058] Furthermore, in the imaging optical system according to one embodiment, the aspherical lens GA may be located on the image plane side of the aperture diaphragm St, and one or more positive lenses may be provided between the aperture diaphragm St and the aspherical lens GA. By arranging the positive lenses on the image plane side of the aperture diaphragm St, the height difference between the pupil paraxial ray and the pupil paraxial ray with respect to the optical axis Z1 can be increased, thereby allowing the aspherical lens GA to have appropriate sensitivity to field curvature and coma aberration.

[0059] Furthermore, the imaging optical system according to one embodiment may satisfy the following condition (12). 0.01 <BF / fa<5.00 ……(12) however, BF: Back focus (the distance from the image-plane side of the lens closest to the image plane in an imaging optical system to the image plane itself). fa: Focal length of the entire system Let's assume that.

[0060] Conditional equation (12) specifies a desirable range for the ratio of the back focus BF to the total focal length fa of the system. If the ratio exceeds the upper limit of conditional equation (12), the back focus BF becomes too long, making it difficult to shorten the overall length. On the other hand, if it falls below the lower limit, it becomes difficult to secure the distance between the image plane and the lens closest to the image plane, resulting in poor manufacturability.

[0061] The lower limit of condition (12) may be set to 0.60. This allows for a shorter back focus (BF) and a shorter overall length. Alternatively, the upper limit of condition (12) may be set to 3.00. This ensures sufficient distance between the image plane and the lens closest to the image plane, thereby improving manufacturability.

[0062] Furthermore, the imaging optical system according to one embodiment may satisfy the following condition (13). 0.001≦fa / |fga|<5.000 ……(13) however, fa: Focal length of the entire system fga: Focal length of the aspherical lens GA Let's assume that.

[0063] If the value falls below the lower limit of condition equation (13), the focal length of the entire system becomes wider, making it difficult to correct aberrations in the entire system. On the other hand, if the value exceeds the upper limit of condition equation (13), the radius of curvature of the aspherical lens GA becomes tighter (smaller), which worsens the manufacturability of the aspherical lens GA.

[0064] The lower limit of condition (13) may be set to 0.010. This allows for a shorter back focus (BF) and thus a shorter overall length. Alternatively, the upper limit of condition (13) may be set to 0.700. This ensures sufficient distance between the image plane and the lens closest to the image plane, thereby improving manufacturability.

[0065] Furthermore, the imaging optical system according to one embodiment may satisfy the following condition (14). 2.3 <Sga<6.0 ……(14) however, Sga: Specific gravity of aspherical lens GA [g / cm³] 3 ] Let's assume that.

[0066] The specific gravity of glass materials generally has a positive correlation with the refractive index, with a tendency for the refractive index to increase as the specific gravity increases. Conditional equation (14) is an equation for appropriately setting the specific gravity of the aspherical lens GA in order to reduce the weight of the lens. If the specific gravity falls below the lower limit of conditional equation (14), the refractive index of the aspherical lens GA becomes too small, and the refractive power of the aspherical lens GA weakens, making it impossible to properly correct distortion and field curvature with the aspherical lens GA. On the other hand, if the specific gravity exceeds the upper limit of conditional equation (14), the specific gravity of the aspherical lens GA becomes too high, making it difficult to reduce the weight of the lens as a whole.

[0067] <3. Examples of application to imaging devices> Next, we will describe a specific example of applying an imaging optical system according to one embodiment of the present disclosure to an imaging device.

[0068] Figure 26 shows an example configuration of an imaging device 100 to which an imaging optical system according to one embodiment is applied. This imaging device 100 is, for example, a digital still camera and comprises a camera block 110, a camera signal processing unit 20, an image processing unit 30, an LCD (Liquid Crystal Display) 40, an R / W (Reader / Writer) 50, a CPU (Central Processing Unit) 60, an input unit 70, and a lens drive control unit 80.

[0069] The camera block 110 is responsible for the imaging function and includes an imaging lens 111 and an image sensor 112 such as a CCD (Charge Coupled Device) or CMOS (Complementary Metal Oxide Semiconductor). The image sensor 112 converts the optical image formed by the imaging lens 111 into an electrical signal, thereby outputting an imaging signal (image signal) corresponding to the optical image. The imaging optical systems 1 to 7 shown in Figure 1 and other examples can be applied as the imaging lens 111.

[0070] The camera signal processing unit 20 performs various signal processing on the image signal output from the image sensor 112, such as analog-to-digital conversion, noise reduction, image quality correction, and conversion to luminance and chromatic difference signals.

[0071] The image processing unit 30 performs recording and playback processing of image signals, and is configured to perform compression encoding, decompression and decoding processing of image signals based on a predetermined image data format, as well as conversion processing of data specifications such as resolution.

[0072] The LCD 40 has the function of displaying various data such as the operation status of the user's input unit 70 and captured images. The R / W 50 writes image data encoded by the image processing unit 30 to the memory card 1000 and reads image data recorded on the memory card 1000. The memory card 1000 is, for example, a semiconductor memory that can be inserted into a slot connected to the R / W 50.

[0073] The CPU 60 functions as a control processing unit that controls each circuit block provided in the imaging device 100, and controls each circuit block based on instruction input signals from the input unit 70. The input unit 70 consists of various switches and the like that the user can operate as needed. For example, the input unit 70 consists of a shutter release button for operating the shutter and a selection switch for selecting an operating mode, and outputs instruction input signals to the CPU 60 according to the user's operation. The lens drive control unit 80 controls the drive of the lenses arranged in the camera block 110, and controls motors (not shown) that drive each lens of the imaging lens 111 based on control signals from the CPU 60.

[0074] The operation of the imaging device 100 will be described below. In the standby state for shooting, under the control of the CPU 60, an image signal corresponding to the image captured by the camera block 110 is output to the LCD 40 via the camera signal processing unit 20 and displayed as a camera-through image. Furthermore, when an instruction input signal for zooming or focusing is input from, for example, the input unit 70, the CPU 60 outputs a control signal to the lens drive control unit 80, and a predetermined lens of the imaging lens 111 moves based on the control of the lens drive control unit 80.

[0075] When the shutter of the camera block 110 (not shown) is operated by an instruction input signal from the input unit 70, the captured image signal is output from the camera signal processing unit 20 to the image processing unit 30, where it is compressed and encoded and converted into digital data in a predetermined data format. The converted data is output to the R / W 50 and written to the memory card 1000.

[0076] Focusing is performed, for example, when the shutter release button on the input unit 70 is half-pressed or fully pressed for recording (shooting), by the lens drive control unit 80 moving a predetermined lens of the imaging lens 111 based on a control signal from the CPU 60.

[0077] When playing back image data recorded on the memory card 1000, in response to an operation on the input unit 70, the R / W 50 reads out predetermined image data from the memory card 1000, the image processing unit 30 performs decompression and decoding processing, and then the playback image signal is output to the LCD 40 and the playback image is displayed.

[0078] In the embodiments described above, an example of applying the imaging device to a digital still camera was shown. However, the scope of application of the imaging device is not limited to digital still cameras, and it can be applied to various other imaging devices. For example, it can be applied to digital SLR cameras, digital non-reflex cameras, digital video cameras, and surveillance cameras. It can also be widely applied as the camera section of digital input / output devices such as mobile phones with cameras and information terminals with cameras. Furthermore, it can be applied to interchangeable lens cameras. [Examples]

[0079] <4. Examples of lens numerical values> Next, a specific numerical example of an imaging optical system according to one embodiment of the present disclosure will be described. Here, an example in which specific numerical values ​​are applied to imaging optical systems 1 to 7 according to each configuration example shown in Figure 1, etc., will be described.

[0080] The meanings of the symbols shown in the following tables and explanations are as follows: "Si" indicates the number of the i-th surface, with the sign increasing sequentially from the object side. "ri" indicates the value of the paraxial radius of curvature of the i-th surface (mm). "di" indicates the value of the distance on the optical axis between the i-th surface and the (i+1)-th surface (mm). "Ndi" indicates the refractive index value of the material of the optical element having the i-th surface for the d-line (wavelength 587.6 nm). "νdi" indicates the Abbe number value of the material of the optical element having the i-th surface for the d-line. "φi" indicates the effective diameter value of the i-th surface (mm). Parts where the value of "ri" is "∞" indicate a plane or aperture surface, etc. "ASP" in the surface number (Si) column indicates that the surface is composed of an aspherical shape. "STO" in the surface number column indicates that an aperture diaphragm St is located at the corresponding position. "OBJ" in the surface number column indicates that the surface is an object surface (subject surface). In the "Face Number" column, "IMG" indicates that the plane is the image plane. "f" indicates the focal length of the entire system (unit: mm). "Fno" indicates the maximum aperture value (F number). "ω" indicates the half-angle of view (unit: °). "Y" indicates the image height (unit: mm). "L" indicates the total optical length (distance along the optical axis Z1 from the plane closest to the object to the image plane IMG) (unit: mm). Furthermore, the angle of incidence of light rays into the imaging optical system is measured from the optical axis Z1, with clockwise being positive and counterclockwise being negative. Also, in Figure 1, etc., the object is assumed to be on the left side of the imaging optical system, and the light rays incident on the imaging optical system from the object side are assumed to travel from left to right.

[0081] Furthermore, some lenses used in each embodiment have lens surfaces composed of aspherical shapes. The aspherical shape is defined by the following formula. In the tables showing the aspherical coefficients described later, "Ei" is expressed as an exponential notation with base 10, i.e., "10 -i This represents "0.12345E-05", for example, "0.12345×10 -5 This represents ".

[0082] (Equation for an aspherical surface) x = 5 2 / (1+(1-(1+k)c2 y 2 ) 1 / 2 )+ΣAi·y i Here, let "x" be the distance from the vertex of the lens surface to the optical axis (sag), "y" be the height perpendicular to the optical axis Z1, "c" be the paraxial curvature (reciprocal of the radius of curvature) at the vertex of the lens surface, and "k" be the conic constant. Ai is the i-th aspherical coefficient.

[0083] [Example 1] Table 1 shows the basic lens data for the imaging optical system 1 according to Example 1 shown in Figure 1. Table 2 shows the values ​​for the overall focal length f, F-number, overall angle of view 2ω, image height Y, and optical length L of the imaging optical system 1 according to Example 1. Note that Table 2 shows the values ​​when the object distance (d0) is at infinity. Tables 3 and 4 show the coefficient values ​​representing the shape of the aspherical surface in the imaging optical system 1 according to Example 1.

[0084] The imaging optical system 1 according to Embodiment 1 comprises six lens components. The six lens components consist of eight lenses L1 to L8, arranged in order from the object side towards the image plane side. The aperture diaphragm St is positioned between lens L1 and lens L2.

[0085] Lens L1 is a biconcave negative lens. Lens L2 is a positive meniscus lens with its convex surface facing the image plane. Lens L3 is a biconcave negative lens. Lenses L2 and L3 are bonded together to form a cemented lens. Lens L4 is a biconvex positive lens. Lens L5 is a biconcave negative lens. Lens L6 is a biconvex positive lens. Lenses L5 and L6 are bonded together to form a cemented lens. Lens L7 is a negative meniscus lens with its convex surface facing the image plane. Lens L8 is a positive meniscus lens with its convex surface facing the object.

[0086] Lenses L4, L7, and L8 are aspherical lenses with aspherical surfaces formed on both sides. In particular, lens L8 has two points where dx / dy = 0 (dx / dy: the first derivative of the sag amount x with respect to the lens diameter y), and is an aspherical lens GA that satisfies the above condition (1).

[0087] In the imaging optical system 1, the distance along the optical axis from the aperture diaphragm St to the object-side surface of lens L8 is DLga in the above conditional equations (7) and (11). Also, the distance from the object-side surface of lens L1 closest to the object to the image-side surface of lens L8 closest to the image plane is DLa in the above conditional equation (7). Furthermore, the distance from the image-side surface of lens L8 closest to the image plane to the image plane is the back focus BF in the above conditional equation (12).

[0088] With the above configuration, an optical system is realized that achieves miniaturization and weight reduction while effectively correcting various aberrations (especially distortion, field curvature, and coma aberration).

[0089] [Table 1]

[0090] [Table 2]

[0091] [Table 3]

[0092] [Table 4]

[0093] Figure 2 shows the longitudinal aberration of the imaging optical system 1 according to Example 1 when it is focused at infinity. Figure 3 shows the transverse aberration of the imaging optical system 1 according to Example 1 when it is focused at infinity.

[0094] Figure 2 shows longitudinal aberrations, including spherical aberration, astigmatism (field curvature), and distortion. In the spherical aberration diagram in Figure 2 and the transverse aberration diagram in Figure 3, the solid line represents the value at the d line (587.56 nm), the dashed line represents the value at the g line (435.84 nm), and the dashed line represents the value at the C line (656.27 nm). In the astigmatism diagram in Figure 2, S represents the value at the sagittal image plane and T represents the value at the tangential image plane. In the astigmatism and distortion diagrams in Figure 2, the value at the d line is shown. The same applies to the aberration diagrams in subsequent embodiments.

[0095] As can be seen from each aberration diagram, the imaging optical system 1 according to Example 1 has good correction of various aberrations and possesses excellent imaging performance.

[0096] [Example 2] Table 5 shows the basic lens data for the imaging optical system 2 according to Example 2 shown in Figure 4. Table 6 shows the values ​​for the overall focal length f, F-number, overall angle of view 2ω, image height Y, and optical length L of the imaging optical system 2 according to Example 2. Note that Table 6 shows the values ​​when the object distance (d0) is at infinity. Tables 7 and 8 show the coefficient values ​​representing the shape of the aspherical surface in the imaging optical system 2 according to Example 2.

[0097] The imaging optical system 2 according to Embodiment 2 comprises nine lens components. The nine lens components consist of 11 lenses L1 to L11, arranged in order from the object side to the image plane side. The aperture diaphragm St is positioned between lens L3 and lens L4.

[0098] Lens L1 is a biconcave negative lens. Lens L2 is a biconvex positive lens. Lens L3 is a biconvex positive lens. Lens L4 is a biconcave negative lens. Lens L5 is a positive meniscus lens with its convex surface facing the image plane. Lens L6 is a biconvex positive lens.

[0099] Lens L7 is a biconvex positive lens. Lens L8 is a biconcave negative lens. Lens L9 is a biconvex positive lens. Lens L10 is a negative meniscus lens with its convex surface facing the image plane. Lens L11 is a negative meniscus lens with its convex surface facing the image plane. Lenses L7 and L8 are bonded together to form a cemented lens. Similarly, lenses L9 and L10 are bonded together to form a cemented lens.

[0100] Lenses L2, L6, and L11 are aspherical lenses with aspherical surfaces formed on both sides. In particular, lens L11 has two points where dx / dy = 0 (dx / dy: the first derivative of the sag amount x with respect to the lens diameter y), and is an aspherical lens GA that satisfies the above condition (1).

[0101] In the imaging optical system 2, the distance along the optical axis from the aperture diaphragm St to the object-side surface of lens L11 is DLga in the above conditions (7) and (11). Also, the distance from the object-side surface of lens L1 closest to the object to the image-side surface of lens L11 closest to the image plane is DLa in the above condition (7). Furthermore, the distance from the image-side surface of lens L11 closest to the image plane to the image plane is the back focus BF in the above condition (12).

[0102] With the above configuration, an optical system is realized that achieves miniaturization and weight reduction while effectively correcting various aberrations (especially distortion, field curvature, and coma aberration).

[0103] [Table 5]

[0104] [Table 6]

[0105] [Table 7]

[0106] [Table 8]

[0107] Figure 5 shows the longitudinal aberration of the imaging optical system 2 according to Example 2 when it is focused at infinity. Figure 6 shows the transverse aberration of the imaging optical system 2 according to Example 2 when it is focused at infinity.

[0108] As can be seen from each aberration diagram, the imaging optical system 2 according to Example 2 has good correction of various aberrations and possesses excellent imaging performance.

[0109] [Example 3] Table 9 shows the basic lens data for the imaging optical system 3 according to Example 3 shown in Figure 7. Table 10 shows the values ​​for the overall focal length f, F-number, overall angle of view 2ω, image height Y, and optical length L for the imaging optical system 3 according to Example 3. Note that Table 10 shows the values ​​when the object distance (d0) is at infinity. Tables 11 and 12 show the coefficient values ​​representing the shape of the aspherical surface in the imaging optical system 3 according to Example 3.

[0110] The imaging optical system 3 according to Embodiment 3 comprises 11 lens components. The 11 lens components consist of 14 lenses L1 to L14, arranged in order from the object side to the image plane side. The aperture diaphragm St is positioned between lens L7 and lens L8.

[0111] Lens L1 is a negative meniscus lens with its convex surface facing the object. Lens L2 is a negative meniscus lens with its convex surface facing the object. Lens L3 is a biconcave negative lens. Lens L4 is a positive meniscus lens with its convex surface facing the object. Lens L5 is a biconcave negative lens. Lens L6 is a biconvex positive lens. Lens L7 is a biconvex positive lens. Lens L8 is a biconvex positive lens. Lens L9 is a biconvex positive lens. Lens L10 is a negative meniscus lens with its convex surface facing the image plane. Lens L11 is a positive meniscus lens with its convex surface facing the image plane. Lens L12 is a biconcave negative lens. Lens L13 is a negative meniscus lens with its convex surface facing the image plane. Lens L14 is a biconvex positive lens. Lenses L3 and L4 are bonded together to form a cemented lens. Lenses L5 and L6 are bonded together to form a cemented lens. Lenses L9 and L10 are bonded together to form a cemented lens.

[0112] Lenses L1, L7, and L13 are aspherical lenses with aspherical surfaces formed on both sides. In particular, lens L13 has two points where dx / dy = 0 (dx / dy: the first derivative of the sag amount x with respect to the lens diameter y), and is an aspherical lens GA that satisfies the above condition (1).

[0113] In the imaging optical system 3, the distance along the optical axis from the aperture diaphragm St to the object-side surface of lens L13 is DLga in the above conditions (7) and (11). Also, the distance from the object-side surface of lens L1 closest to the object to the image-side surface of lens L14 closest to the image plane is DLa in the above condition (7). Furthermore, the distance from the image-side surface of lens L14 closest to the image plane to the image plane is the back focus BF in the above condition (12).

[0114] With the above configuration, an optical system is realized that achieves miniaturization and weight reduction while effectively correcting various aberrations (especially distortion, field curvature, and coma aberration).

[0115] [Table 9]

[0116] [Table 10]

[0117] [Table 11]

[0118] [Table 12]

[0119] Figure 8 shows the longitudinal aberration of the imaging optical system 3 according to Example 3 when it is focused at infinity. Figure 9 shows the transverse aberration of the imaging optical system 3 according to Example 3 when it is focused at infinity.

[0120] As can be seen from each aberration diagram, the imaging optical system 3 according to Example 3 has good correction of various aberrations and possesses excellent imaging performance.

[0121] [Example 4] Table 13 shows the basic lens data for the imaging optical system 4 according to Example 4 shown in Figure 10. Table 14 shows the values ​​for the total focal length f, F-number, total angle of view 2ω, image height Y, and total optical length L for the imaging optical system 4 according to Example 4. Table 15 shows the data for the surface spacing that becomes variable during zooming in the imaging optical system 4 according to Example 4. Note that Tables 14 and 15 show the values ​​for the wide-angle end (Wide) and telephoto end (Tele) respectively when the object distance (d0) is at infinity. Tables 16, 17, and 18 show the coefficient values ​​representing the shape of the aspherical surface in the imaging optical system 4 according to Example 4. Table 19 shows the starting surface and focal length (unit: mm) of each lens group in the imaging optical system 4 according to Example 4.

[0122] The imaging optical system 4 according to Embodiment 4 comprises 12 lens components. The 12 lens components consist of 16 lenses L1 to L16 arranged in order from the object side to the image plane side. The aperture diaphragm St is positioned between lens L7 and lens L8.

[0123] The imaging optical system 4 according to Embodiment 4 constitutes a zoom lens in which the first lens group G1 to the sixth lens group G6 are arranged sequentially from the object side toward the image plane side.

[0124] The first lens group G1 consists of lenses L1 to L4, arranged in order from the object side to the image plane side. Lens L1 is a negative meniscus lens with its convex surface facing the object side. Lens L2 is a negative meniscus lens with its convex surface facing the image plane side. Lens L3 is a negative lens with a biconcave shape. Lens L4 is a positive meniscus lens with its convex surface facing the object side.

[0125] The second lens group G2 consists of lenses L5 and L6, arranged in order from the object side towards the image plane side. Lens L5 is a negative meniscus lens with its convex surface facing the object side. Lens L6 is a positive meniscus lens with its convex surface facing the object side. Lenses L5 and L6 are bonded together to form a cemented lens.

[0126] The third lens group G3 consists of lens L7. Lens L7 is a positive meniscus lens with its convex surface facing the object.

[0127] The fourth lens group G4 consists of lenses L8 to L10, arranged in order from the object side to the image plane side. Lens L8 is a negative meniscus lens with its convex surface facing the object side. Lens L9 is a positive meniscus lens with its convex surface facing the object side. Lens L10 is a positive lens with a biconvex shape. Lenses L8 and L9 are bonded together to form a cemented lens.

[0128] The fifth lens group G5 consists of lenses L11 and L12, arranged in order from the object side to the image plane side. Lens L11 is a biconvex positive lens. Lens L12 is a biconcave negative lens. Lenses L11 and L12 are bonded together to form a cemented lens.

[0129] The sixth lens group G6 consists of lenses L13 to L16, arranged in order from the object side to the image plane side. Lens L13 is a biconvex positive lens. Lens L14 is a biconvex positive lens. Lens L15 is a biconcave negative lens. Lens L16 is a negative meniscus lens with its convex surface facing the object side. Lenses L14 and L15 are bonded together to form a cemented lens.

[0130] In the imaging optical system 4 according to Embodiment 4, when zooming from the wide-angle end to the telephoto end, the first lens group G1 moves toward the image plane, the second lens group G2 moves toward the object, the third lens group G3 moves toward the object, the fourth lens group G4 moves toward the object, the fifth lens group G5 moves toward the object, and the sixth lens group G6 moves toward the object.

[0131] Lenses L1, L2, L7, L10, and L16 are aspherical lenses with aspherical surfaces formed on both sides. In particular, lenses L2 and L16 have two points where dx / dy = 0 (dx / dy: the first derivative of the sag amount x with respect to the lens diameter y), and are aspherical lenses GA that satisfy the above condition (1).

[0132] In the imaging optical system 3, the distance along the optical axis from the object-side surface of lens L2 to the aperture diaphragm St, or the distance along the optical axis from the aperture diaphragm St to the object-side surface of lens L16, is DLga in the above conditions (7) and (11). Also, the distance from the object-side surface of lens L1, which is closest to the object, to the image-side surface of lens L16, which is closest to the image plane, is DLa in the above condition (7). Also, the distance from the image-side surface of lens L16, which is closest to the image plane, to the image plane is the back focus BF in the above condition (12).

[0133] With the above configuration, an optical system is realized that achieves miniaturization and weight reduction while effectively correcting various aberrations (especially distortion, field curvature, and coma aberration).

[0134] [Table 13]

[0135] [Table 14]

[0136] [Table 15]

[0137] [Table 16]

[0138] [Table 17]

[0139] [Table 18]

[0140] [Table 19]

[0141] Figure 11 shows the longitudinal aberration of the imaging optical system 4 according to Example 4 at the wide-angle end and when focused at infinity. Figure 12 shows the longitudinal aberration of the imaging optical system 4 according to Example 4 at the telephoto end and when focused at infinity. Figure 13 shows the transverse aberration of the imaging optical system 4 according to Example 4 at the wide-angle end and when focused at infinity. Figure 14 shows the transverse aberration of the imaging optical system 4 according to Example 4 at the telephoto end and when focused at infinity.

[0142] As can be seen from each aberration diagram, the imaging optical system 4 according to Example 4 has good correction of various aberrations and possesses excellent imaging performance.

[0143] [Example 5] Table 20 shows the basic lens data for the imaging optical system 5 according to Example 5 shown in Figure 15. Table 21 shows the values ​​for the total focal length f, F-number, total angle of view 2ω, image height Y, and total optical length L for the imaging optical system 5 according to Example 5. Note that Table 21 shows the values ​​when the object distance (d0) is at infinity. Tables 22 and 23 show the coefficient values ​​representing the shape of the aspherical surface in the imaging optical system 5 according to Example 5.

[0144] The imaging optical system 5 according to Embodiment 5 comprises six lens components. The six lens components consist of eight lenses L1 to L8, arranged in order from the object side towards the image plane side. The aperture diaphragm St is positioned between lens L1 and lens L2.

[0145] Lens L1 is a positive meniscus lens with its convex surface facing the object. Lens L2 is a positive meniscus lens with its convex surface facing the image plane. Lens L3 is a negative lens with a biconcave shape. Lens L4 is a positive lens with a biconvex shape. Lens L5 is a negative lens with a biconcave shape. Lens L6 is a positive lens with a biconvex shape. Lens L7 is a positive meniscus lens with its convex surface facing the image plane. Lens L8 is a negative meniscus lens with its convex surface facing the object. Lenses L2 and L3 are bonded together to form a cemented lens. Similarly, lenses L5 and L6 are bonded together to form a cemented lens.

[0146] Lenses L4, L7, and L8 are aspherical lenses with aspherical surfaces formed on both sides. In particular, lens L8 has two points where dx / dy = 0 (dx / dy: the first derivative of the sag amount x with respect to the lens diameter y), and is an aspherical lens GA that satisfies the above condition (1).

[0147] In the imaging optical system 5, the distance along the optical axis from the aperture diaphragm St to the object-side surface of lens L8 is DLga in the above conditions (7) and (11). Also, the distance from the object-side surface of lens L1 closest to the object to the image-side surface of lens L8 closest to the image plane is DLa in the above condition (7). Also, the distance from the image-side surface of lens L8 closest to the image plane to the image plane is the back focus BF in the above condition (12).

[0148] With the above configuration, an optical system is realized that achieves miniaturization and weight reduction while effectively correcting various aberrations (especially distortion, field curvature, and coma aberration).

[0149] [Table 20]

[0150] [Table 21]

[0151] [Table 22]

[0152] [Table 23]

[0153] Figure 16 shows the longitudinal aberration of the imaging optical system 5 according to Example 5 when it is focused at infinity. Figure 17 shows the transverse aberration of the imaging optical system 5 according to Example 5 when it is focused at infinity.

[0154] As can be seen from each aberration diagram, the imaging optical system 5 according to Example 5 has good correction of various aberrations and possesses excellent imaging performance.

[0155] [Example 6] Table 24 shows the basic lens data for the imaging optical system 6 according to Example 6 shown in Figure 18. Table 25 shows the values ​​for the total focal length f, F-number, total angle of view 2ω, image height Y, and total optical length L for the imaging optical system 6 according to Example 6. Note that Table 25 shows the values ​​when the object distance (d0) is at infinity. Table 26 shows the coefficient values ​​representing the shape of the aspherical surface in the imaging optical system 6 according to Example 6.

[0156] The imaging optical system 6 according to Embodiment 6 comprises 11 lens components. The 11 lens components consist of 14 lenses L1 to L14, arranged in order from the object side to the image plane side. The aperture diaphragm St is positioned between lens L7 and lens L8.

[0157] Lens L1 is a negative meniscus lens with its convex surface facing the object. Lens L2 is a negative meniscus lens with its convex surface facing the object. Lens L3 is a positive meniscus lens with its convex surface facing the object. Lens L4 is a biconcave negative lens. Lens L5 is a positive meniscus lens with its convex surface facing the object. Lens L6 is a biconvex positive lens. Lens L7 is a negative meniscus lens with its convex surface facing the object. Lens L8 is a biconvex positive lens. Lens L9 is a biconcave negative lens. Lens L10 is a positive meniscus lens with its convex surface facing the image plane. Lens L11 is a negative meniscus lens with its convex surface facing the image plane. Lens L12 is a biconvex positive lens. Lens L13 is a negative meniscus lens with its convex surface facing the object. Lens L14 is a biconcave negative lens. Lenses L4 and L5 are bonded together to form a cemented lens. Lenses L8 and L9 are bonded together to form a cemented lens. Lenses L10 and L11 are bonded together to form a cemented lens.

[0158] Lenses L2 and L13 are aspherical lenses with aspherical surfaces formed on both sides. In particular, lens L13 has two points where dx / dy = 0 (dx / dy: first derivative of sag amount x with respect to lens diameter y), and is an aspherical lens GA that satisfies the above condition (1).

[0159] In the imaging optical system 6, the distance along the optical axis from the aperture diaphragm St to the object-side surface of lens L13 is DLga in the above conditions (7) and (11). Also, the distance from the object-side surface of lens L1 closest to the object to the image-side surface of lens L14 closest to the image plane is DLa in the above condition (7). Furthermore, the distance from the image-side surface of lens L14 closest to the image plane to the image plane is the back focus BF in the above condition (12).

[0160] With the above configuration, an optical system is realized that achieves miniaturization and weight reduction while effectively correcting various aberrations (especially distortion, field curvature, and coma aberration).

[0161] [Table 24]

[0162] [Table 25]

[0163] [Table 26]

[0164] Figure 19 shows the longitudinal aberration of the imaging optical system 6 according to Example 6 when it is focused at infinity. Figure 20 shows the transverse aberration of the imaging optical system 6 according to Example 6 when it is focused at infinity.

[0165] As can be seen from each aberration diagram, the imaging optical system 6 according to Example 6 has excellent aberration correction and superior imaging performance.

[0166] [Example 7] Table 27 shows the basic lens data for the imaging optical system 7 according to Example 7 shown in Figure 21. Table 28 shows the values ​​for the overall focal length f, F-number, overall angle of view 2ω, image height Y, and optical length L for the imaging optical system 7 according to Example 7. Note that Table 28 shows the values ​​when the object distance (d0) is at infinity. Tables 29 and 30 show the coefficient values ​​representing the shape of the aspherical surface in the imaging optical system 7 according to Example 7.

[0167] The imaging optical system 7 according to Embodiment 7 comprises 13 lens components. The 13 lens components consist of 14 lenses L1 to L14 arranged in order from the object side to the image plane side. The aperture diaphragm St is positioned between lens L7 and lens L8.

[0168] Lens L1 is a negative meniscus lens with its convex surface facing the object. Lens L2 is a positive lens with a biconvex shape. Lens L3 is a negative lens with a biconcave shape. Lens L4 is a positive meniscus lens with its convex surface facing the object. Lens L5 is a negative lens with a biconcave shape. Lens L6 is a positive lens with a biconvex shape. Lens L7 is a positive lens with a biconvex shape. Lens L8 is a positive lens with a biconvex shape. Lens L9 is a positive lens with a biconvex shape. Lens L10 is a negative lens with a biconcave shape. Lens L11 is a positive lens with a biconvex shape. Lens L12 is a negative lens with a biconcave shape. Lens L13 is a positive meniscus lens with its convex surface facing the image plane. Lens L14 is a positive meniscus lens with its convex surface facing the image plane. Lenses L5 and L6 are bonded together to form a cemented lens. Lenses L9 and L10 are bonded together to form a cemented lens.

[0169] Lenses L1, L2, L7, and L13 are aspherical lenses with aspherical surfaces formed on both sides. In particular, lenses L2 and L13 have two points where dx / dy = 0 (dx / dy: the first derivative of the sag amount x with respect to the lens diameter y), and are aspherical lenses GA that satisfy the above condition (1).

[0170] In the imaging optical system 7, the distance on the optical axis from the object-side surface of the lens L2 to the aperture stop St, or the distance on the optical axis from the aperture stop St to the object-side surface of the lens L13 is DLga in the above conditional expressions (7) and (11). Further, the distance from the object-side surface of the most object-side lens L1 to the image-side surface of the most image-side lens L14 is DLa in the above conditional expression (7). Further, the distance from the image-side surface of the most image-side lens L14 to the image plane is the back focus BF in the above conditional expression (12).

[0171] With the above configuration, an optical system is realized that achieves miniaturization and weight reduction while favorably correcting various aberrations (particularly distortion aberration, field curvature, and coma aberration).

[0172] [Table 27]

[0173] [Table 28]

[0174] [Table 29]

[0175] [Table 24]

[0176] [Table 30]

[0177] FIG. 22 shows the longitudinal aberration of the imaging optical system 7 according to Example 7 at infinity focus. FIG. 23 shows the lateral aberration of the imaging optical system 7 according to Example 7 at infinity focus.

[0178] As can be seen from each aberration diagram, the imaging optical system 7 according to Example 7 has excellent aberration correction and superior imaging performance.

[0179] [Other numerical data for each example] Tables 31 and 32 summarize the values ​​for each of the above-mentioned conditional expressions for each example. As can be seen from Tables 31 and 32, the values ​​for each example for each conditional expression fall within the specified numerical range.

[0180] [Table 31]

[0181] [Table 32]

[0182] <5. Application Examples> [5.1 First Application Example] The technology disclosed herein can be applied to a variety of products. For example, the technology disclosed herein may be implemented as a device mounted on any type of mobile vehicle, such as automobiles, electric vehicles, hybrid electric vehicles, motorcycles, bicycles, personal mobility devices, airplanes, drones, ships, robots, construction machinery, or agricultural machinery (tractors).

[0183] Figure 27 is a block diagram showing a schematic configuration example of a vehicle control system 7000, which is an example of a mobile control system to which the technology described herein can be applied. The vehicle control system 7000 comprises a plurality of electronic control units connected via a communication network 7010. In the example shown in Figure 27, the vehicle control system 7000 comprises a drive system control unit 7100, a body system control unit 7200, a battery control unit 7300, an external information detection unit 7400, an internal information detection unit 7500, and an integrated control unit 7600. The communication network 7010 connecting these plurality of control units may be an in-vehicle communication network compliant with any standard such as CAN (Controller Area Network), LIN (Local Interconnect Network), LAN (Local Area Network), or FlexRay®.

[0184] Each control unit comprises a microcomputer that performs calculations according to various programs, a storage unit that stores programs executed by the microcomputer or parameters used in various calculations, and a drive circuit that drives various controlled devices. Each control unit is equipped with a network interface for communication with other control units via the communication network 7010, and a communication interface for communication with devices or sensors inside or outside the vehicle via wired or wireless communication. Figure 27 illustrates the functional configuration of the integrated control unit 7600, which includes a microcomputer 7610, a general-purpose communication interface 7620, a dedicated communication interface 7630, a positioning unit 7640, a beacon receiver 7650, an in-vehicle equipment interface 7660, an audio / image output unit 7670, an in-vehicle network interface 7680, and a storage unit 7690. Other control units similarly include a microcomputer, a communication interface, and a storage unit.

[0185] The drivetrain control unit 7100 controls the operation of devices related to the vehicle's drivetrain according to various programs. For example, the drivetrain control unit 7100 functions as a control device for generating driving force for the vehicle, such as an internal combustion engine or a drive motor; a driving force transmission mechanism for transmitting driving force to the wheels; a steering mechanism for adjusting the steering angle of the vehicle; and a braking device for generating braking force for the vehicle. The drivetrain control unit 7100 may also function as a control device such as ABS (Antilock Brake System) or ESC (Electronic Stability Control).

[0186] A vehicle state detection unit 7110 is connected to the drivetrain control unit 7100. The vehicle state detection unit 7110 includes, for example, a gyro sensor for detecting the angular velocity of the vehicle's axial rotational motion, an acceleration sensor for detecting the vehicle's acceleration, or at least one of the sensors for detecting the amount of operation of the accelerator pedal, the amount of operation of the brake pedal, the steering angle of the steering wheel, the engine speed, or the rotational speed of the wheels. The drivetrain control unit 7100 performs calculations using signals input from the vehicle state detection unit 7110 and controls the internal combustion engine, drive motor, electric power steering system, brake system, etc.

[0187] The body system control unit 7200 controls the operation of various devices mounted on the vehicle body according to various programs. For example, the body system control unit 7200 functions as a control device for a keyless entry system, a smart key system, a power window system, or various lamps such as headlights, reverse lights, brake lights, turn signals, or fog lights. In this case, the body system control unit 7200 may receive radio waves transmitted from a portable device that replaces a key or signals from various switches. The body system control unit 7200 receives these radio waves or signals and controls the vehicle's door lock system, power window system, lamps, etc.

[0188] The battery control unit 7300 controls the secondary battery 7310, which is the power source for the drive motor, according to various programs. For example, the battery control unit 7300 receives information such as battery temperature, battery output voltage, or remaining battery capacity from the battery device equipped with the secondary battery 7310. The battery control unit 7300 uses these signals to perform calculations and controls the temperature of the secondary battery 7310 or the cooling device provided in the battery device.

[0189] The external information detection unit 7400 detects information from outside the vehicle equipped with the vehicle control system 7000. For example, at least one of the imaging unit 7410 and the external information detection unit 7420 is connected to the external information detection unit 7400. The imaging unit 7410 includes at least one of the following: a ToF (Time Of Flight) camera, a stereo camera, a monocular camera, an infrared camera, and other cameras. The external information detection unit 7420 includes at least one of the following: an environmental sensor for detecting the current weather or climate, or an ambient information detection sensor for detecting other vehicles, obstacles, or pedestrians around the vehicle equipped with the vehicle control system 7000.

[0190] The environmental sensor may be at least one of the following: a raindrop sensor for detecting rain, a fog sensor for detecting fog, a sunshine sensor for detecting the degree of sunlight, and a snow sensor for detecting snowfall. The ambient information detection sensor may be at least one of the following: an ultrasonic sensor, a radar device, and a LIDAR (Light Detection and Ranging, Laser Imaging Detection and Ranging) device. These imaging unit 7410 and external information detection unit 7420 may be provided as independent sensors or devices, or as a device in which multiple sensors or devices are integrated.

[0191] Here, FIG. 28 shows an example of the installation positions of the imaging unit 7410 and the out-vehicle information detection unit 7420. The imaging units 7910, 7912, 7914, 7916, 7918 are provided, for example, at at least one position among the front nose, side mirrors, rear bumper, back door of the vehicle 7900, and the upper part of the front windshield inside the vehicle cabin. The imaging unit 7910 provided at the front nose and the imaging unit 7918 provided at the upper part of the front windshield inside the vehicle cabin mainly acquire images in front of the vehicle 7900. The imaging units 7912, 7914 provided on the side mirrors mainly acquire images on the sides of the vehicle 7900. The imaging unit 7916 provided on the rear bumper or the back door mainly acquires images behind the vehicle 7900. The imaging unit 7918 provided at the upper part of the front windshield inside the vehicle cabin is mainly used for detecting a preceding vehicle or pedestrians, obstacles, traffic lights, traffic signs, or lanes.

[0192] Note that FIG. 28 shows an example of the imaging ranges of the respective imaging units 7910, 7912, 7914, 7916. The imaging range a indicates the imaging range of the imaging unit 7910 provided at the front nose, and the imaging ranges b and c respectively indicate the imaging ranges of the imaging units 7912 and 7914 provided on the side mirrors. The imaging range d indicates the imaging range of the imaging unit 7916 provided on the rear bumper or the back door. For example, by overlapping the image data captured by the imaging units 7910, 7912, 7914, 7916, an overhead image of the vehicle 7900 seen from above can be obtained.

[0193] The out-vehicle information detection units 7920, 7922, 7924, 7926, 7928, 7930 provided at the front, rear, sides, corners of the vehicle 7900, and the upper part of the front windshield inside the vehicle cabin may be, for example, ultrasonic sensors or radar devices. The out-vehicle information detection units 7920, 7926, 7930 provided at the front nose, rear bumper, back door of the vehicle 7900, and the upper part of the front windshield inside the vehicle cabin may be, for example, LIDAR devices. These out-vehicle information detection units 7920 to 7930 are mainly used for detecting a preceding vehicle, pedestrians, or obstacles.

[0194] Returning to Figure 27, the explanation continues. The external information detection unit 7400 causes the imaging unit 7410 to capture images of the area outside the vehicle and receives the captured image data. The external information detection unit 7400 also receives detection information from the connected external information detection unit 7420. If the external information detection unit 7420 is an ultrasonic sensor, radar device, or LIDAR device, the external information detection unit 7400 emits ultrasonic waves or electromagnetic waves and receives information on the received reflected waves. Based on the received information, the external information detection unit 7400 may perform object detection processing such as detecting people, vehicles, obstacles, signs, or characters on the road surface, or distance detection processing. Based on the received information, the external information detection unit 7400 may perform environmental recognition processing to recognize rainfall, fog, or road surface conditions. Based on the received information, the external information detection unit 7400 may calculate the distance to an object outside the vehicle.

[0195] Furthermore, the external information detection unit 7400 may perform image recognition processing or distance detection processing to recognize people, vehicles, obstacles, signs, or characters on the road surface based on the received image data. The external information detection unit 7400 may perform distortion correction or alignment processing on the received image data, and may also synthesize image data captured by different imaging units 7410 to generate an overhead view image or a panoramic image. The external information detection unit 7400 may also perform viewpoint transformation processing using image data captured by different imaging units 7410.

[0196] The in-vehicle information detection unit 7500 detects information inside the vehicle. The in-vehicle information detection unit 7500 is connected to, for example, a driver status detection unit 7510 that detects the driver's state. The driver status detection unit 7510 may include a camera that images the driver, a biosensor that detects the driver's biometric information, or a microphone that collects sounds inside the vehicle. The biosensor is installed, for example, on the seat or steering wheel and detects the biometric information of a passenger sitting in the seat or a driver holding the steering wheel. Based on the detection information input from the driver status detection unit 7510, the in-vehicle information detection unit 7500 may calculate the driver's level of fatigue or concentration, or determine whether the driver is dozing off. The in-vehicle information detection unit 7500 may perform processing such as noise cancellation on the collected audio signals.

[0197] The integrated control unit 7600 controls the overall operation of the vehicle control system 7000 according to various programs. An input unit 7800 is connected to the integrated control unit 7600. The input unit 7800 is implemented by a device that can be operated by the passenger, such as a touch panel, buttons, a microphone, a switch, or a lever. The integrated control unit 7600 may also receive data obtained by voice recognition of voice input from the microphone. The input unit 7800 may be a remote control device using infrared or other radio waves, or an external device such as a mobile phone or PDA (Personal Digital Assistant) that is compatible with the operation of the vehicle control system 7000. The input unit 7800 may be a camera, in which case the passenger can input information by gesture. Alternatively, data obtained by detecting the movement of a wearable device worn by the passenger may be input. Furthermore, the input unit 7800 may include, for example, an input control circuit that generates an input signal based on the information input by the passenger using the above input unit 7800 and outputs it to the integrated control unit 7600. Passengers and others can input various data or instruct the vehicle control system 7000 to perform processing operations by operating this input unit 7800.

[0198] The memory unit 7690 may include a ROM (Read Only Memory) for storing various programs executed by a microcomputer, and a RAM (Random Access Memory) for storing various parameters, calculation results, or sensor values. The memory unit 7690 may also be implemented using a magnetic storage device such as an HDD (Hard Disk Drive), a semiconductor storage device, an optical storage device, or a magneto-optical storage device.

[0199] The general-purpose communication interface 7620 is a general-purpose communication interface that mediates communication between the vehicle and various devices present in the external environment 7750. The general-purpose communication interface 7620 may implement cellular communication protocols such as GSM (Global System of Mobile communications), WiMAX (registered trademark), LTE (registered trademark) (Long Term Evolution), or LTE-A (LTE-Advanced), or other wireless communication protocols such as wireless LAN (also known as Wi-Fi (registered trademark)) or Bluetooth (registered trademark). The general-purpose communication interface 7620 may connect to devices (e.g., application servers or control servers) located on an external network (e.g., the Internet, a cloud network, or a carrier-specific network) via, for example, a base station or access point. The general-purpose communication interface 7620 may also connect to terminals located near the vehicle (e.g., terminals for drivers, pedestrians, or shops, or MTC (Machine Type Communication) terminals) using, for example, P2P (Peer To Peer) technology.

[0200] The Dedicated Communication I / F 7630 is a communication interface that supports communication protocols developed for use in vehicles. The Dedicated Communication I / F 7630 may implement standard protocols such as WAVE (Wireless Access in Vehicle Environment), DSRC (Dedicated Short Range Communications), or cellular communication protocols, which are combinations of lower-layer IEEE 802.11p and upper-layer IEEE 1609. The Dedicated Communication I / F 7630 typically performs V2X communication, a concept that includes one or more of the following: vehicle-to-vehicle communication, vehicle-to-infrastructure communication, vehicle-to-home communication, and vehicle-to-pedestrian communication.

[0201] The positioning unit 7640 performs positioning by receiving GNSS signals from GNSS (Global Navigation Satellite System) satellites (for example, GPS signals from GPS (Global Positioning System) satellites) and generates location information including the vehicle's latitude, longitude, and altitude. The positioning unit 7640 may also determine its current location by exchanging signals with a wireless access point, or it may acquire location information from a terminal such as a mobile phone, PHS, or smartphone that has a positioning function.

[0202] The beacon receiver 7650 receives radio waves or electromagnetic waves transmitted from, for example, a radio station installed on a road, and obtains information such as the current location, traffic congestion, road closures, or travel time. The functions of the beacon receiver 7650 may also be included in the dedicated communication interface 7630 described above.

[0203] The in-vehicle equipment interface (I / F) 7660 is a communication interface that mediates connections between the microcomputer 7610 and various in-vehicle equipment 7760 located inside the vehicle. The in-vehicle equipment interface (I / F) 7660 may establish a wireless connection using wireless communication protocols such as Wi-Fi, Bluetooth®, NFC (Near Field Communication), or WUSB (Wireless USB). The in-vehicle equipment interface (I / F) 7660 may also establish a wired connection such as USB (Universal Serial Bus), HDMI® (High-Definition Multimedia Interface), or MHL (Mobile High-Definition Link) via connection terminals (and cables if necessary) not shown. The in-vehicle equipment 7760 may include, for example, at least one of the following: a mobile device or wearable device owned by a passenger, or information equipment brought into or installed in the vehicle. The in-vehicle equipment 7760 may also include a navigation device that performs route searching to any destination. The in-vehicle equipment interface 7660 exchanges control signals or data signals with these in-vehicle equipment units 7760.

[0204] The in-vehicle network interface 7680 is an interface that mediates communication between the microcomputer 7610 and the communication network 7010. The in-vehicle network interface 7680 transmits and receives signals and other data in accordance with a predetermined protocol supported by the communication network 7010.

[0205] The microcomputer 7610 of the integrated control unit 7600 controls the vehicle control system 7000 according to various programs based on information acquired via at least one of the general-purpose communication I / F 7620, dedicated communication I / F 7630, positioning unit 7640, beacon receiver 7650, in-vehicle equipment I / F 7660, and in-vehicle network I / F 7680. For example, the microcomputer 7610 may calculate control target values ​​for the drive force generator, steering mechanism, or braking device based on acquired in-vehicle and out-of-vehicle information and output control commands to the drive system control unit 7100. For example, the microcomputer 7610 may perform coordinated control aimed at realizing ADAS (Advanced Driver Assistance System) functions, including vehicle collision avoidance or impact mitigation, following driving based on distance between vehicles, maintaining vehicle speed, vehicle collision warning, or vehicle lane departure warning. Furthermore, the microcomputer 7610 may perform cooperative control for purposes such as autonomous driving, where the vehicle drives autonomously without driver intervention, by controlling the drive force generating device, steering mechanism, or braking device, etc., based on the acquired information about the vehicle's surroundings.

[0206] The microcomputer 7610 may generate three-dimensional distance information between the vehicle and surrounding structures, people, and other objects based on information acquired via at least one of the general-purpose communication I / F 7620, dedicated communication I / F 7630, positioning unit 7640, beacon receiver 7650, in-vehicle equipment I / F 7660, and in-vehicle network I / F 7680, and create local map information including surrounding information of the vehicle's current location. Furthermore, the microcomputer 7610 may predict dangers such as vehicle collision, proximity of pedestrians, or entry into a closed road based on the acquired information, and generate a warning signal. The warning signal may, for example, be a signal to generate a warning sound or illuminate a warning lamp.

[0207] The audio-image output unit 7670 transmits at least one of audio and image output signals to an output device capable of visually or audibly notifying the vehicle's occupants or those outside the vehicle. In the example in Figure 27, the output devices are exemplified as an audio speaker 7710, a display unit 7720, and an instrument panel 7730. The display unit 7720 may include, for example, at least one of an onboard display and a head-up display. The display unit 7720 may also have an AR (Augmented Reality) display function. The output device may be other devices other than these, such as headphones, wearable devices such as glasses-type displays worn by occupants, projectors, or lamps. If the output device is a display device, the display device visually displays the results obtained from various processes performed by the microcomputer 7610 or information received from other control units in various formats such as text, images, tables, and graphs. If the output device is an audio output device, the audio output device converts the audio signal, consisting of reproduced audio data or sound data, into an analog signal and outputs it audibly.

[0208] In the example shown in Figure 27, at least two control units connected via the communication network 7010 may be integrated into a single control unit. Alternatively, each control unit may be composed of multiple control units. Furthermore, the vehicle control system 7000 may include other control units not shown. Also, in the above description, some or all of the functions performed by one control unit may be assigned to other control units. In other words, as long as information is transmitted and received via the communication network 7010, predetermined calculation processing may be performed by any of the control units. Similarly, a sensor or device connected to one control unit may be connected to another control unit, and multiple control units may transmit and receive detection information to each other via the communication network 7010.

[0209] In the vehicle control system 7000 described above, the imaging optical system and imaging device of this disclosure can be applied to the imaging unit 7410 and the imaging units 7910, 7912, 7914, 7916, and 7918.

[0210] [5.2 Second Application Example] The technology relating to this disclosure can be applied to medical imaging systems. Medical imaging systems are medical systems that use imaging technology, such as endoscope systems and microscope systems.

[0211] [Endoscopy System] An example of an endoscopic system will be explained using Figures 29 and 30. Figure 29 is a diagram showing an example of the schematic configuration of an endoscopic system 5000 to which the technology relating to this disclosure can be applied. Figure 30 is a diagram showing an example of the configuration of an endoscope 5001 and a CCU (Camera Control Unit) 5039. Figure 29 illustrates a surgeon (e.g., a physician) 5067, who is a participant in the surgery, performing surgery on a patient 5071 on a patient bed 5069 using the endoscopic system 5000. As shown in Figure 29, the endoscopic system 5000 consists of an endoscope 5001, which is a medical imaging device, a CCU 5039, a light source device 5043, a recording device 5053, an output device 5055, and a support device 5027 that supports the endoscope 5001.

[0212] In endoscopic surgery, an insertion aid called a trocca 5025 is inserted into the patient 5071. Then, via the trocca 5025, the scope 5003 connected to the endoscope 5001 and surgical instruments 5021 are inserted into the patient 5071's body. Surgical instruments 5021 include, for example, energy devices such as electrosurgical units or forceps.

[0213] Surgical images, which are medical images of the inside of patient 5071 taken by endoscope 5001, are displayed on display device 5041. The surgeon 5067 performs the procedure on the surgical target using surgical instruments 5021 while viewing the surgical images displayed on display device 5041. Note that the medical images are not limited to surgical images; they may also be diagnostic images taken during diagnosis.

[0214] [Endoscopy] The endoscope 5001 is an imaging unit that images the inside of the patient 5071's body. For example, as shown in Figure 30, it is a camera 5005 that includes a focusing optical system 50051 that focuses incident light, a zoom optical system 50052 that changes the focal length of the imaging unit to enable optical zoom, a focusing optical system 50053 that changes the focal length of the imaging unit to enable focus adjustment, and a light-receiving element 50054. The endoscope 5001 generates a pixel signal by focusing light onto the light-receiving element 50054 via the connected scope 5003 and outputs the pixel signal to the CCU 5039 through a transmission system. The scope 5003 is an insertion unit that has an objective lens at its tip and guides light from the connected light source device 5043 into the patient 5071's body. The scope 5003 is, for example, a rigid scope in the case of a rigid endoscope, or a flexible scope in the case of a flexible endoscope. The scope 5003 may be a straight-viewing endoscope or an oblique-viewing endoscope. Furthermore, the pixel signal can be any signal based on the signal output from the pixel, such as a RAW signal or an image signal. Alternatively, the transmission system connecting the endoscope 5001 and the CCU 5039 may be equipped with memory to store parameters related to the endoscope 5001 and the CCU 5039. The memory may be located, for example, at the connection point of the transmission system or on the cable. For example, the factory settings of the endoscope 5001 and parameters that change during power-up may be stored in the transmission system's memory, and the operation of the endoscope may be modified based on the parameters read from the memory. The endoscope and transmission system may also be referred to as a set. The photodetector 50054 is a sensor that converts received light into a pixel signal, and is, for example, a CMOS (Complementary Metal Oxide Semiconductor) type image sensor. Preferably, the photodetector 50054 is a color image sensor with a Bayer array. Furthermore, the light-receiving element 50054 is preferably an image sensor having a number of pixels corresponding to a resolution of, for example, 4K (3840 horizontal pixels × 2160 vertical pixels), 8K (7680 horizontal pixels × 4320 vertical pixels), or square 4K (3840 or more horizontal pixels × 3840 or more vertical pixels). The light-receiving element 50054 may be a single sensor chip or multiple sensor chips.For example, a prism may be provided to separate the incident light into predetermined wavelength bands, and each wavelength band may be imaged by a different photodetector. Alternatively, multiple photodetectors may be provided for stereoscopic viewing. The photodetector 50054 may be a sensor containing an image processing circuit within its chip structure, or it may be a Time of Flight (ToF) sensor. The transmission system may be, for example, an optical fiber cable or wireless transmission. Wireless transmission is only required if the pixel signals generated by the endoscope 5001 can be transmitted. For example, the endoscope 5001 and the CCU 5039 may be wirelessly connected, or the endoscope 5001 and the CCU 5039 may be connected via a base station in the operating room. In this case, the endoscope 5001 may simultaneously transmit not only the pixel signals but also information related to the pixel signals (e.g., pixel signal processing priority and synchronization signals). The endoscope may integrate the scope and camera, or a photodetector may be provided at the tip of the scope.

[0215] [CCU (Camera Control Unit)] The CCU5039 is a control device that comprehensively controls the connected endoscope 5001 and light source device 5043. For example, as shown in Figure 30, it is an information processing device having an FPGA 50391, CPU 50392, RAM 50393, ROM 50394, GPU 50395, and I / F 50396. The CCU5039 may also comprehensively control the connected display device 5041, recording device 5053, and output device 5055. For example, the CCU5039 controls the irradiation timing, irradiation intensity, and type of light source of the light source device 5043. The CCU5039 also performs image processing such as development processing (e.g., demosaicing) and correction processing on the pixel signals output from the endoscope 5001, and outputs the processed pixel signals (e.g., images) to external devices such as the display device 5041. The CCU5039 also transmits control signals to the endoscope 5001 to control its operation. The control signal is, for example, information regarding imaging conditions such as the magnification and focal length of the imaging unit. The CCU 5039 may also have an image downconversion function and be configured to simultaneously output high-resolution (e.g., 4K) images to the display device 5041 and low-resolution (e.g., HD) images to the recording device 5053.

[0216] Furthermore, the CCU5039 may be connected to external devices (e.g., recording devices, display devices, output devices, support devices) via an IP converter that converts signals to a predetermined communication protocol (e.g., IP (Internet Protocol)). The connection between the IP converter and the external devices may consist of a wired network, or some or all of the network may be constructed as a wireless network. For example, the IP converter on the CCU5039 side may have a wireless communication function and transmit the received video to an IP switcher or output-side IP converter via a wireless communication network such as a fifth-generation mobile communication system (5G) or a sixth-generation mobile communication system (6G).

[0217] [Light source device] The light source device 5043 is a device capable of irradiating light in a predetermined wavelength band, and includes, for example, a plurality of light sources and a light source optical system that guides the light from the plurality of light sources. The light sources are, for example, xenon lamps, LED light sources, and LD light sources. The light source device 5043 has, for example, LED light sources corresponding to each of the three primary colors R, G, and B, and emits white light by controlling the output intensity and output timing of each light source. In addition, the light source device 5043 may have a light source capable of irradiating special light used for special light observation, separate from the light source that irradiates normal light used for normal light observation. Special light is light in a predetermined wavelength band different from the normal light used for normal light observation, and includes, for example, near-infrared light (light with a wavelength of 760 nm or more), infrared light, blue light, and ultraviolet light. Normal light is, for example, white light or green light. In narrow-band light observation, a type of special light observation, by alternately irradiating with blue light and green light, it is possible to take high-contrast images of predetermined tissues such as blood vessels on the surface of mucous membranes by utilizing the wavelength dependence of light absorption in body tissues. Furthermore, in fluorescence observation, a type of special light observation, excitation light is irradiated to excite a drug injected into body tissue, and a fluorescence image is obtained by receiving the fluorescence emitted by the body tissue or the labeling drug. This makes it easier for the operator to visualize body tissues and other areas that are difficult to see with normal light. For example, in fluorescence observation using infrared light, infrared light having an excitation wavelength band is irradiated onto a drug such as indocyanine green (ICG) injected into body tissue, and the structure of the body tissue and the affected area can be made easier to visualize by receiving the fluorescence of the drug. In addition, in fluorescence observation, a drug that is excited by special light in the blue wavelength band and emits fluorescence in the red wavelength band (e.g., 5-ALA) may be used. The type of irradiation light of the light source device 5043 is set by the control of the CCU 5039. The CCU 5039 may have a mode in which normal light observation and special light observation are performed alternately by controlling the light source device 5043 and the endoscope 5001. In this case, it is preferable that information based on the pixel signal obtained in special light observation is superimposed on the pixel signal obtained in normal light observation. Furthermore, special light observation may include infrared light observation, which involves irradiating with infrared light to view areas deeper than the organ surface, or multispectral observation utilizing hyperspectral spectroscopy. In addition, photodynamic therapy may be combined with this method.

[0218] [Recording device] The recording device 5053 is a device that records pixel signals (e.g., images) acquired from the CCU 5039, and is, for example, a recorder. The recording device 5053 records the images acquired from the CCU 5039 onto an HDD, SSD, or optical disc. The recording device 5053 may be connected to the hospital network and made accessible from equipment outside the operating room. The recording device 5053 may also have an image down-conversion or up-conversion function.

[0219] [Display device] The display device 5041 is a device capable of displaying images, such as a display monitor. The display device 5041 displays a display image based on pixel signals acquired from the CCU 5039. The display device 5041 may also function as an input device that enables eye-tracking, voice recognition, and gesture-based instruction input by equipping it with a camera and microphone.

[0220] [Output device] The output device 5055 is a device that outputs information acquired from the CCU 5039, and is, for example, a printer. The output device 5055 prints a print image on paper based on the pixel signals acquired from the CCU 5039.

[0221] [Support device] The support device 5027 is a multi-joint arm comprising a base portion 5029 having an arm control device 5045, an arm portion 5031 extending from the base portion 5029, and a holding portion 5032 attached to the tip of the arm portion 5031. The arm control device 5045 is composed of a processor such as a CPU and controls the driving of the arm portion 5031 by operating according to a predetermined program. The support device 5027 controls parameters such as the length of each link 5035 constituting the arm portion 5031 and the rotation angle and torque of each joint 5033 by the arm control device 5045, thereby controlling, for example, the position and orientation of the endoscope 5001 held by the holding portion 5032. This allows the endoscope 5001 to be changed to a desired position or orientation, enabling the scope 5003 to be inserted into the patient 5071 and changing the observation area inside the body. The support device 5027 functions as an endoscope support arm that supports the endoscope 5001 during surgery. This allows the support device 5027 to act as a substitute for the scopist, who is an assistant holding the endoscope 5001. The support device 5027 may also be a device that supports the microscope device 5301, which will be described later, and can also be called a medical support arm. The support device 5027 may be controlled autonomously by the arm control device 5045, or it may be controlled by the arm control device 5045 based on user input. For example, the control method may be a master-slave system in which the support device 5027, acting as a slave device (replica device) that is a patient cart, is controlled based on the movement of the master device (primary device), which is the operator console at the user's location. Furthermore, the support device 5027 may be controlled remotely from outside the operating room.

[0222] The above describes an example of an endoscope system 5000 to which the technology described herein may be applied. For example, the technology described herein may be applied to a microscope system.

[0223] [Microscope System] Figure 31 shows an example of a schematic configuration of a microsurgical system to which the technology described herein may be applied. In the following description, components similar to those in the endoscopic system 5000 are denoted by the same reference numerals, and redundant explanations are omitted.

[0224] Figure 31 schematically shows a surgeon 5067 performing surgery on patient 5071 on a patient bed 5069 using a microsurgical system 5300. For simplicity, Figure 31 omits the cart 5037 from the configuration of the microsurgical system 5300, and the microscope device 5301, which replaces the endoscope 5001, is shown in a simplified form. However, in this description, the microscope device 5301 may refer to the microscope unit 5303 located at the tip of the link 5035, or it may refer to the entire configuration including the microscope unit 5303 and the support device 5027.

[0225] As shown in Figure 31, during surgery, the image of the surgical area captured by the microscope device 5301 is displayed enlarged on a display device 5041 installed in the operating room using the microsurgery system 5300. The display device 5041 is positioned opposite the surgeon 5067, and the surgeon 5067 observes the surgical area through the image displayed on the display device 5041 and performs various procedures on the surgical area, such as excision of the affected area. The microsurgery system is used, for example, in ophthalmic surgery and neurosurgery.

[0226] Examples of endoscopic systems 5000 and microsurgical systems 5300 to which the technology relating to this disclosure may be applied have been described above. However, the systems to which the technology relating to this disclosure may be applied are not limited to these examples. For example, the support device 5027 may support other observation devices or surgical instruments at its tip in place of the endoscope 5001 or the microscope unit 5303. Such other observation devices may include, for example, forceps, insufflation tubes for pneumoperitoneum, or energy treatment instruments for tissue incision or blood vessel sealing by cauterization. By supporting these observation devices and surgical instruments with the support device, their position can be fixed more stably than when medical staff support them manually, and the burden on medical staff can be reduced. The technology relating to this disclosure may also be applied to support devices that support components other than the microscope unit.

[0227] The technology relating to this disclosure can be suitably applied to the camera 5005 among the configurations described above. In particular, the imaging optical system of this disclosure can be suitably applied to at least some of the optical systems in the camera 5005, including the condensing optical system 50051, the zoom optical system 50052, and the focusing optical system 50053.

[0228] <6. Other Embodiments> The technology described herein is not limited to the above-described embodiment and examples, and various modifications are possible.

[0229] For example, the shapes and numerical values ​​of each part shown in the above embodiment and example are merely examples of how to implement this technology, and the technical scope of this technology should not be interpreted in a restrictive way based on these.

[0230] Furthermore, for example, the configuration may include a different number of lenses than those shown in the above embodiment and example. Moreover, the configuration may further include lenses that have substantially no refractive power.

[0231] For example, this technology can also take the following configuration. According to the present technology with the following configuration, by optimizing the shape and position of the aspherical lens and appropriately using the aspherical lens, it is possible to provide an imaging optical system that can correct various aberrations well while achieving miniaturization and weight reduction, and an imaging device equipped with such an imaging optical system.

[0232] [1] Multiple lenses, including aspherical lenses, Aperture diaphragm and Equipped with, Let y be the lens diameter of the aspherical lens, and x be the sag of the aspherical surface of the aspherical lens. Let x1, x2, ..., xn be the sag amounts at the points on the aspherical surface of the aspherical lens where dx / dy = 0 (dx / dy: the first derivative of the sag amount x with respect to the lens diameter y). The amount of sag at the position where the lens diameter y is the effective radius of light is x n+1 , |x i -x i-1 When xm is the maximum value of |(i=2,…n+1), The following conditions must be met: Imaging optical system. 0.01 <xm / Dga<0.50 ……(1) n≧2 ……(2) 1.644<0.0024*Vga+Nga<2.400 ……(3) 1.893<0.0093*Vga+Nga<3.000 ……(4) 0.3 <Lexp / Lgaf<50.0 ……(5) however, Dga: Effective ray radius of the aspherical surface of the aspherical lens. Vga: Abbe number of the aspherical lens Nga: Refractive index of the aspherical lens Lgaf: The distance from the object-side surface of the aspherical lens to the image plane. Lexp: Distance from the exit pupil to the image plane of the optical system. Let's assume that. [2] Multiple lenses, including aspherical lenses, Aperture diaphragm and Equipped with, Let y be the lens diameter of the aspherical lens, and x be the sag of the aspherical surface of the aspherical lens. Let x1, x2, ..., xn be the sag amounts at the points on the aspherical surface of the aspherical lens where dx / dy = 0 (dx / dy: the first derivative of the sag amount x with respect to the lens diameter y). The amount of sag at the position where the lens diameter y is the effective radius of light is x n+1 , |x i -x i-1 When xm is the maximum value of |(i=2,…n+1), The following conditions must be met: Imaging optical system. 0.01 <xm / Dga<0.50 ……(1) n≧2 ……(2) 1.644<0.0024*Vga+Nga<2.400 ……(3) 1.893<0.0093*Vga+Nga<3.000 ……(4) 0.05 <Lenp / Lgae<50.00 ……(6) however, Dga: Effective ray radius of the aspherical surface of the aspherical lens. Vga: Abbe number of the aspherical lens Nga: Refractive index of the aspherical lens Lgae: The distance from the object-side surface of the lens closest to the object among the multiple lenses to the aspherical lens. Lenp: The distance from the object-side surface of the lens closest to the object among the multiple lenses to the exit pupil of the optical system. Let's assume that. [3] Furthermore, the following conditions must be met: The imaging optical system described in [1] or [2] above. 0.01<|DLga| / DLa<1.00 ……(7) however, DLga: Distance along the optical axis between the object-side surface of the aspherical lens and the aperture diaphragm. DLa: The distance from the object-side surface of the lens closest to the object among the multiple lenses to the image-side surface of the lens closest to the image plane among the multiple lenses. Let's assume that. [4] Furthermore, the following conditions must be met: The imaging optical system described in any one of the above [1] to [3]. -20.0 <hga^ / hgf^≦1.0 ……(8) however, hga^: Height of the pupillary paraxial ray when passing through the aspherical lens. hgf^: Height of the pupil's paraxial ray when passing through the lens closest to the object among the aforementioned multiple lenses. Let's assume that. [5] Furthermore, the following conditions must be met: An imaging optical system as described in any one of the above [1] to [4]. -20.0 <hga^ / hgb^≦1.0 ……(9) however, hga^: Height of the pupillary paraxial ray when passing through the aspherical lens. hgb^: Height of the pupil's paraxial ray when passing through the lens closest to the image plane among the aforementioned multiple lenses. Let's assume that. [6] Furthermore, the following conditions must be met: The imaging optical system described in any one of the above [1] to [5]. 0.01≦hga 2 *hga^ 2 / hi 4 <10.00 ……(10) however, hga: Height of the pupillary meriaxial ray when passing through the aspherical lens. hga^: Height of the pupillary paraxial ray when passing through the aspherical lens. hi: Radius of the aperture diameter of the optical system Let's assume that. [7] Furthermore, the following conditions must be met: The imaging optical system described in any one of the above [1] to [6]. -4.0 <DLga / fa<5.0 ……(11) however, DLga: Distance along the optical axis between the object-side surface of the aspherical lens and the aperture diaphragm. fa: Focal length of the entire system Let's assume that. [8] The plurality of lenses comprises at least six lenses. The imaging optical system described in any one of the above [1] to [7]. [9] The aspherical lens is located on the image plane side of the aperture diaphragm, and has one or more positive lenses between the aperture diaphragm and the aspherical lens. The imaging optical system described in any one of the above [1] to [8].

[10] Furthermore, the following conditions must be met: The imaging optical system described in any one of the above [1] to [9]. 0.01 <BF / fa<5.00 ……(12) however, BF: The distance from the image-plane-side surface of the lens closest to the image plane in the imaging optical system to the image plane (back focus). fa: Focal length of the entire system Let's assume that.

[11] Furthermore, the following conditions must be met: The imaging optical system described in any one of the above [1] to

[10] . 0.001≦fa / |fga|<5.000 ……(13) however, fa: Focal length of the entire system fga: Focal length of the aspherical lens Let's assume that.

[12] Furthermore, the following conditions must be met: The imaging optical system described in any one of the above [1] to

[11] . 2.3 <Sga<6.0 ……(14) however, Sga: Specific gravity of the aspherical lens [g / cm³] 3 ] Let's assume that.

[13] It includes an imaging optical system and an image sensor that outputs an imaging signal corresponding to the optical image formed by the imaging optical system, The aforementioned imaging optical system is Multiple lenses, including aspherical lenses, Aperture diaphragm and Equipped with, Let y be the lens diameter of the aspherical lens, and x be the sag of the aspherical surface of the aspherical lens. Let x1, x2, ..., xn be the sag amounts at the points on the aspherical surface of the aspherical lens where dx / dy = 0 (dx / dy: the first derivative of the sag amount x with respect to the lens diameter y). The amount of sag at the position where the lens diameter y is the effective radius of light is x n+1 , |x i -x i-1 When xm is the maximum value of |(i=2,…n+1), The following conditions must be met: Imaging device. 0.01 <xm / Dga<0.50 ……(1) n≧2 ……(2) 1.644<0.0024*Vga+Nga<2.400 ……(3) 1.893<0.0093*Vga+Nga<3.000 ……(4) 0.3 <Lexp / Lgaf<50.0 ……(5) however, Dga: Effective ray radius of the aspherical surface of the aspherical lens. Vga: Abbe number of the aspherical lens Nga: Refractive index of the aspherical lens Lgaf: The distance from the object-side surface of the aspherical lens to the image plane. Lexp: Distance from the exit pupil to the image plane of the optical system. Let's assume that.

[14] It includes an imaging optical system and an image sensor that outputs an imaging signal corresponding to the optical image formed by the imaging optical system, The aforementioned imaging optical system is Multiple lenses, including aspherical lenses, Aperture diaphragm and Equipped with, Let y be the lens diameter of the aspherical lens, and x be the sag of the aspherical surface of the aspherical lens. Let x1, x2, ..., xn be the sag amounts at the points on the aspherical surface of the aspherical lens where dx / dy = 0 (dx / dy: the first derivative of the sag amount x with respect to the lens diameter y). The amount of sag at the position where the lens diameter y is the effective radius of light is x n+1 , |x i -x i-1 When xm is the maximum value of |(i=2,…n+1), The following conditions must be met: Imaging device. 0.01 <xm / Dga<0.50 ……(1) n≧2 ……(2) 1.644<0.0024*Vga+Nga<2.400 ……(3) 1.893<0.0093*Vga+Nga<3.000 ……(4) 0.05 <Lenp / Lgae<50.00 ……(6) however, Dga: Effective ray radius of the aspherical surface of the aspherical lens. Vga: Abbe number of the aspherical lens Nga: Refractive index of the aspherical lens Lgae: The distance from the object-side surface of the lens closest to the object among the multiple lenses to the aspherical lens. Lenp: The distance from the object-side surface of the lens closest to the object among the multiple lenses to the exit pupil of the optical system. Let's assume that.

[15] It also includes lenses that have virtually no refractive power. The imaging optical system described in any one of the above [1] to

[12] .

[16] The imaging optical system further comprises a lens that has substantially no refractive power. The imaging apparatus described in

[13] or

[14] above. [Explanation of Symbols]

[0233] G1...First lens group, G2...Second lens group, G3...Third lens group, G4...Fourth lens group, G5...Fifth lens group, G6...Sixth lens group, GA...Aspherical lens, IMG...Image plane, St...Aperture diaphragm, Z1...Optical axis, 1-7...Imaging optical system, 110...Camera block, 111...Imaging lens, 112...Image sensor, 20...Camera signal processing unit, 30...Image processing unit, 40...LCD 50...R / W (Reader / Writer), 60...CPU, 70...Input unit, 80...Lens drive control unit, 100...Imaging device, 1000...Memory card, 5005...Camera, 50051...Collecting optical system, 50052...Zoom optical system, 50053...Focus optical system, 50054...Photodetector, 7410...Imaging unit, 7910, 7912, 7914, 7916, 7918...Imaging unit.

Claims

1. Multiple lenses, including aspherical lenses, Aperture diaphragm and Equipped with, The plurality of lenses comprises at least six lenses having refractive power. Let y be the lens diameter of the aspherical lens, and x be the sag of the aspherical surface of the aspherical lens. The sag amounts at the points on the aspherical surface of the aspherical lens where dx / dy = 0 (dx / dy: the first derivative of the sag amount x with respect to the lens diameter y) are x1, x2, ..., xn. The amount of sag at the position where the lens diameter y is the effective radius of light is x n+1 , | x i -x i-1 When the maximum value of |(i=2, ..., n+1) is xm, The following conditions must be met: Imaging optical system. 0.01<xm / Dga<0.50...(1) n ≥ 2 ……(2) 1.644<0.0024*Vga+Nga<2.400...(3) 1.893<0.0093*Vga+Nga<3.000...(4) 0.3<Lexp / Lgaf<50.0...(5) 0.01≦hga 2 *hga^ 2 / hi 4 <10.00 ...(10) 0.60<BF / fa<5.00...(12)' however, Dga: Effective ray radius at the aspherical surface of the aspherical lens. Vga: Abbe number of the aspherical lens Nga: Refractive index of the aspherical lens Lgaf: Distance from the object-side surface of the aspherical lens to the image plane. Lexp: Distance from the exit pupil of the optical system to the image plane. hga: Height of the pupillary paraxial ray when passing through the object-side surface of the aspherical lens. hga^: Height of the pupillary paraxial ray when passing through the object-side surface of the aspherical lens. hi: Radius of the aperture diameter of the optical system BF: The distance from the image-plane-side surface of the lens closest to the image plane in the imaging optical system to the image plane (back focus). fa: Focal length of the entire system Let's assume that.

2. Furthermore, the following conditions must be met: The imaging optical system according to claim 1. 0.01<|DLga| / DLa<1.00...(7) however, DLga: Distance along the optical axis between the object-side surface of the aspherical lens and the aperture diaphragm. DLa: The distance from the object-side surface of the lens closest to the object among the plurality of lenses to the image-side surface of the lens closest to the image plane among the plurality of lenses. Let's assume that.

3. Furthermore, the following conditions must be met: The imaging optical system according to claim 1. -20.0<hga^ / hgf^≦1.0...(8) however, hga^: Height of the pupillary paraxial ray when passing through the object-side surface of the aspherical lens. hgf^: Height of the pupil's paraxial ray when it passes through the object-side surface of the lens closest to the object among the plurality of lenses. Let's assume that.

4. Furthermore, the following conditions must be met: The imaging optical system according to claim 1. -20.0<hga^ / hgb^≦1.0...(9) however, hga^: Height of the pupillary paraxial ray when passing through the object-side surface of the aspherical lens. hgb^: Height of the pupil's paraxial ray when it passes through the object-side surface of the lens closest to the image plane among the plurality of lenses. Let's assume that.

5. Furthermore, the following conditions must be met: The imaging optical system according to claim 1. -4.0<DLga / fa<5.0...(11) however, DLga: Distance along the optical axis between the object-side surface of the aspherical lens and the aperture diaphragm. fa: Focal length of the entire system Let's assume that.

6. The aspherical lens is located on the image plane side of the aperture diaphragm, and has one or more positive lenses between the aperture diaphragm and the aspherical lens. The imaging optical system according to claim 1.

7. Furthermore, the following conditions must be met: The imaging optical system according to claim 1. 0.001≦fa / |fga|<5.000 …(13) however, fa: Focal length of the entire system fga: Focal length of the aspherical lens Let's assume that.

8. Furthermore, the following conditions must be met: The imaging optical system according to claim 1. 2.3<Sga<6.0...(14) however, Sga: Specific gravity of the aspherical lens [g / cm³] 3 ] Let's assume that.

9. It includes an imaging optical system and an image sensor that outputs an imaging signal corresponding to the optical image formed by the imaging optical system, The aforementioned imaging optical system is Multiple lenses, including aspherical lenses, Aperture diaphragm and Equipped with, The plurality of lenses comprises at least six lenses having refractive power. Let y be the lens diameter of the aspherical lens, and x be the sag of the aspherical surface of the aspherical lens. The sag amounts at the points on the aspherical surface of the aspherical lens where dx / dy = 0 (dx / dy: the first derivative of the sag amount x with respect to the lens diameter y) are x1, x2, ..., xn. The amount of sag at the position where the lens diameter y is the effective radius of light is x n+1 , | x i -x i-1 When the maximum value of |(i=2, ..., n+1) is xm, The following conditions must be met: Imaging device. 0.01<xm / Dga<0.50...(1) n ≥ 2 ……(2) 1.644<0.0024*Vga+Nga<2.400...(3) 1.893<0.0093*Vga+Nga<3.000...(4) 0.3<Lexp / Lgaf<50.0...(5) 0.01≦hga 2 *hga^ 2 / hi 4 <10.00 ...(10) 0.60<BF / fa<5.00...(12)' however, Dga: Effective ray radius at the aspherical surface of the aspherical lens. Vga: Abbe number of the aspherical lens Nga: Refractive index of the aspherical lens Lgaf: Distance from the object-side surface of the aspherical lens to the image plane. Lexp: Distance from the exit pupil of the optical system to the image plane. hga: Height of the pupillary paraxial ray when passing through the object-side surface of the aspherical lens. hga^: Height of the pupillary paraxial ray when passing through the object-side surface of the aspherical lens. hi: Radius of the aperture diameter of the optical system BF: The distance from the image-plane-side surface of the lens closest to the image plane in the imaging optical system to the image plane (back focus). fa: Focal length of the entire system Let's assume that.

10. It also features lenses that have virtually no refractive power. The imaging optical system according to any one of claims 1 to 8.

11. The imaging optical system further comprises a lens that has substantially no refractive power. The imaging device according to claim 9.

Images