Imaging lenses and imaging devices

Abstract

This imaging lens comprises, in order from the object side to the image plane side where the imaging element is arranged: a front lens system having positive refractive power; and a rear lens system having a lens surface on the side most toward the image plane that is concave toward the image plane side near the optical axis and convex toward the image plane side in the peripheral portion, the imaging lens satisfies the following conditional expression: (1) 1.0 < Gun2R2 (sag6‑sag10) / (TTL / 2Y)<2.8,(2)5.0(%)<OD MAX <20.0(%).

Description

Technical Field

[0001] The present invention relates to an imaging lens that forms an optical image of a subject on an imaging element such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor), and an imaging device equipped with such an imaging lens. Background Art

[0002] For digital still cameras, low-profile cameras such as card-type cameras are produced year by year, and the size of the imaging device is expected to be reduced. In addition, in the pursuit of design for smartphones or tablet computers, the size of the imaging device is expected to be reduced to ensure sufficient space for installing many functions to achieve miniaturization and differentiation of the terminal itself. Therefore, there is an increasing demand for further size reduction of the imaging lens installed on the imaging device. In addition, while reducing the size of imaging elements such as CCD and CMOS, progress has been made in increasing the number of pixels by miniaturizing the pixel pitch of the imaging element. Along with this, high performance is also expected for the imaging lens used in such an imaging device. Known examples of such small and high-performance imaging lenses include the imaging lenses described in PTL 1 and PTL 2.

[0003] Citation List

[0004] Patent Literature

[0005] PTL 1: International Publication No. WO2013 / 187405

[0006] PTL 2: International Publication No. WO2015 / 098226 Summary of the invention

[0007] Meanwhile, there has been a demand for increasing the element size (size of the imaging surface) of the imaging element in order to enable high-sensitivity shooting while preventing image quality from being deteriorated due to noise in shooting in a dark place.

[0008] It is desirable to provide a small-sized, high-performance imaging lens as an optical system, which is suitable for an imaging element of a large element size and has various aberrations well corrected, and an imaging apparatus mounted with such an imaging lens.

[0009] An imaging lens according to an embodiment of the present disclosure includes, in order from the object side to the side of the image plane on which an imaging element is arranged: a front group lens system having positive refractive power; and a rear group lens system having, on a side closest to the image plane, a lens surface which is concave toward the image plane side in the vicinity of the optical axis and convex toward the image plane side in a peripheral portion, and satisfies the following conditional expression:

[0010] 1.0<Gun2R2 (sag6-sag10) / (TTL / 2Y)<2.8......(1)

[0011] 5.0(%)<OD MAX <20.0(%)......(2),

[0012] in

[0013] Gun2R2 (sag6-sag10) It indicates the distance between two points parallel to the optical axis, on the lens surface closest to the image plane of the rear lens system, between the point where the principal ray of 60% image height intersects and the point where the principal ray of 100% image height intersects (unit: "mm").

[0014] TTL is the distance from the vertex of the lens surface on the side of the front lens system closest to the object to the image plane on the optical axis.

[0015] 2Y represents the diagonal length of the imaging element, and

[0016] OD MAX represents the maximum value of the distortion aberration within the imaging area generated by the imaging lens 300 .

[0017] An imaging device according to an embodiment of the present disclosure includes: an imaging lens; an imaging element that outputs an imaging signal corresponding to an optical image formed by the imaging lens; and an operation unit that corrects distortion aberration of an image captured by the imaging element, and the imaging lens is configured by the imaging lens according to an embodiment of the present disclosure.

[0018] In the imaging lens or imaging device according to the embodiment of the present disclosure, as a configuration of an optical system suitable for an imaging element of a large element size and having a small size, the front lens system and the rear lens system arranged sequentially from the object side to the image plane side are optimized, and various aberrations are well corrected. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a block diagram showing an overview of an imaging device according to an embodiment of the present disclosure.

[0020] Figure 2 is a lens cross-sectional diagram of a first configuration example of an imaging lens according to an embodiment of the present disclosure.

[0021] Figure 3 is a lens cross-sectional diagram of a second configuration example of the imaging lens according to the embodiment.

[0022] Figure 4 is a lens cross-sectional diagram of a third configuration example of the imaging lens according to the embodiment.

[0023] Figure 5is a lens cross-sectional diagram of a fourth configuration example of the imaging lens according to the embodiment.

[0024] Figure 6 is a lens cross-sectional diagram of a fifth configuration example of the imaging lens according to the embodiment.

[0025] Figure 7 is a lens cross-sectional diagram of a sixth configuration example of the imaging lens according to the embodiment.

[0026] Figure 8 is a lens cross-sectional diagram of a seventh configuration example of the imaging lens according to the embodiment.

[0027] Fig. 9 is a lens cross-sectional diagram of an eighth configuration example of the imaging lens according to the embodiment.

[0028] Fig.10 is a lens cross-sectional diagram of a ninth configuration example of the imaging lens according to the embodiment.

[0029] Fig.11 is a lens cross-sectional diagram of a tenth configuration example of the imaging lens according to the embodiment.

[0030] Fig.12 is a lens cross-sectional diagram of an eleventh configuration example of the imaging lens according to the embodiment.

[0031] Fig.13 is a lens cross-sectional diagram of a twelfth configuration example of the imaging lens according to the embodiment.

[0032] Fig.14 is the parameter Gun2R2 in the conditional expression (1). (sag6-sag10) An illustration of the overview of .

[0033] Fig.15 is to show that a specific value is applied to Figure 2 Aberration diagrams of various aberrations in Numerical Example 1 of the imaging lens shown.

[0034] Fig.16 is to show that a specific value is applied to Figure 3 Aberration diagrams of various aberrations in Numerical Example 2 of the imaging lens shown.

[0035] Fig.17 is to show that a specific value is applied to Figure 4 Aberration diagrams of various aberrations in Numerical Example 3 of the imaging lens shown.

[0036] Fig.18 is to show that a specific value is applied to Figure 5 Aberration diagrams of various aberrations in Numerical Example 4 of the imaging lens shown.

[0037] Fig.19 is to show that a specific value is applied to Figure 6 Aberration diagrams of various aberrations in Numerical Example 5 of the imaging lens shown.

[0038] Fig. 20 is to show that a specific value is applied to Figure 7 Aberration diagrams of various aberrations in Numerical Example 6 of the imaging lens shown.

[0039] Fig.21 is to show that a specific value is applied to Figure 8 Aberration diagrams of various aberrations in Numerical Example 7 of the imaging lens shown.

[0040] Fig. 22 is to show that a specific value is applied to Fig. 9 Aberration diagrams of various aberrations in Numerical Example 8 of the imaging lens shown.

[0041] Fig.23 is to show that a specific value is applied to Fig.10 Aberration diagrams of various aberrations in Numerical Example 9 of the imaging lens shown.

[0042] Fig.24 is to show that a specific value is applied to Fig.11 Aberration diagrams of various aberrations in Numerical Example 10 of the imaging lens shown.

[0043] Fig.25 is to show that a specific value is applied to Fig.12 Aberration diagrams of various aberrations in Numerical Example 11 of the imaging lens shown.

[0044] Fig.26 is to show that a specific value is applied to Fig.13 Aberration diagrams of various aberrations in Numerical Example 12 of the imaging lens shown.

[0045] Fig. 27 is a front view showing a configuration example of the imaging apparatus.

[0046] Fig.28 is a rear view showing a configuration example of the imaging apparatus.

[0047] Fig.29 is a block diagram showing an example of a schematic configuration of a vehicle control system.

[0048] Fig.30 It is a diagram for explaining an example of the installation positions of the vehicle exterior information detection section and the imaging section.

[0049] Fig.31 This is a diagram showing an example of a schematic configuration of an endoscopic surgery system.

[0050] Fig.32 Is a description Fig.31 A block diagram of an example of the functional configuration of a camera head and a camera control unit (CCU) described in FIG. DETAILED DESCRIPTION

[0051] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the description is given in the following order.

[0052] 0. Comparison example

[0053] 1. Basic configuration of imaging equipment

[0054] 2. Basic lens configuration

[0055] 3. Function and effect

[0056] 4. Specific application examples of imaging equipment

[0057] 5. Numerical Examples of Lenses

[0058] 6. Practical application examples

[0059] 6.1 First practical application example

[0060] 6.2 Second practical application example

[0061] 7. Other embodiments

[0062] <0. Comparative Example>

[0063] PTL 1 describes an imaging lens that meets the following conditions:

[0064] 0.60<L / 2Y<0.95

[0065] in

[0066] L represents the total length of the imaging lens, and

[0067] 2Y represents the length of the diagonal line of the imaging plane (the length of the diagonal line of the rectangular effective pixel area of ​​the solid-state imaging element).

[0068] In the imaging lens described in PTL 1, in order to achieve further size reduction of the imaging lens while increasing the element size of the imaging element (the size of the imaging surface) to achieve high-sensitivity shooting, it is necessary to reduce the value of the above conditional expression. In the numerical example described in PTL 1, the minimum value of the above conditional expression is 0.69; in order to further shorten the total length of the imaging lens from this value, it is difficult to ensure the necessary optical performance using the technology described in PTL 1 alone due to insufficient correction of off-axis aberrations. Therefore, there is room for improvement by considering the number of lenses, the optical power configuration, and the shape of the lens on the side closest to the image plane.

[0069] In addition, PTL 2 describes an imaging lens that satisfies the following conditions:

[0070] 0.55<L inf / D<0.80

[0071] in

[0072] L inf represents the distance on the optical axis from the lens surface closest to the subject to the image plane, and

[0073] D represents the diagonal length of the effective imaging area.

[0074] In the imaging lens described in PTL 2, in order to achieve further size reduction of the imaging lens while increasing the element size of the imaging element to achieve high-sensitivity shooting, it is necessary to reduce the value of the above conditional expression. In the numerical example described in PTL 2, the minimum value of the above conditional expression is 0.582; in order to further shorten the total length of the imaging lens from this value, it is difficult to ensure the necessary optical performance using the technology described in PTL 2 alone due to insufficient correction of off-axis aberrations. In addition, in the case of using an imaging element with a large D, it is difficult to ensure the necessary optical performance using the number of lenses and the focal length configuration described in PTL 2 so as to ensure good performance while shortening the total length. Therefore, there is room for improvement by considering the number of lenses, the optical focal length configuration, and the shape of the lens on the side closest to the image plane.

[0075] Therefore, it is desirable to provide a high-performance imaging lens of a small size for an optical system, which is suitable for an imaging element of a large element size and has various aberrations well corrected, and an imaging apparatus mounted with such an imaging lens.

[0076] <1. Basic configuration of imaging equipment>

[0077] Figure 1 FIG. 2 shows a configuration example of an imaging device according to an embodiment of the present disclosure. Figure 1 As described in the figure, the imaging device according to the embodiment of the present invention includes an imaging lens 300, an imaging element 301, and an operation unit 302. The imaging element 301 performs conversion into an electric imaging signal based on an optical image formed on an image plane IMG by the imaging lens 300, and is composed of, for example, a solid-state imaging element such as a CCD or a CMOS. The image plane (image forming plane) of the imaging lens 300 is set to coincide with the imaging surface of the imaging element 301.

[0078] The operation unit 302 acquires the image captured by the imaging element 301 and performs various types of image processing. The operation unit 302 includes an image acquisition section 303 that acquires the image captured by the imaging element 301, and a distortion aberration image correction section 304 that outputs an image that has been subjected to such image processing to correct distortion aberration on the acquired image.

[0079] <2. Basic configuration of lens>

[0080] Figures 2 to 13 1 to 12 configuration examples of the imaging lens 300 according to the embodiment of the present disclosure are shown, which will be applied to Figure 1 An imaging lens 300 in an imaging device is shown in FIG. Figure 2 A first configuration example of the imaging lens 300 according to an embodiment of the present disclosure is shown. Figure 3 A second configuration example of the imaging lens 300 according to the embodiment is shown. Figure 4 A third configuration example of the imaging lens 300 according to the embodiment is shown. Figure 5 A fourth configuration example of the imaging lens 300 according to the embodiment is shown. Figure 6 A fifth configuration example of the imaging lens 300 according to the embodiment is shown. Figure 7 A sixth configuration example of the imaging lens 300 is shown. Figure 8 A seventh configuration example of the imaging lens 300 is shown. Fig. 9 An eighth configuration example of the imaging lens 300 is shown. Fig.10 A ninth configuration example of the imaging lens 300 is shown. Fig.11 A tenth configuration example of the imaging lens 300 is shown. Fig.12 An eleventh configuration example of the imaging lens 300 is shown. Fig.13 A twelfth configuration example of the imaging lens 300 is shown. Numerical examples in which specific numerical values ​​are applied to these configuration examples are described later.

[0081] exist Figure 2 In the figure, the symbol IMG represents the image plane, Z1 represents the optical axis, St represents the aperture stop. The imaging element 301 (such as CCD and CMOS) Figure 1 ) can be arranged near the image plane IMG. Between the imaging lens 300 and the image plane IMG, optical components such as a sealing glass SG for protecting the imaging element and various filters can be arranged.

[0082] In the following, appropriately combined Figure 2 A description is given of the configuration of the imaging lens 300 according to an embodiment of the present disclosure based on the configuration examples shown in and the like; however, the technology according to the present disclosure is not limited to the illustrated configuration examples.

[0083] The imaging lens 300 according to the embodiment is composed of a front lens group Gun1 and a rear lens group Gun2 in order from the object side to the image plane side along the optical axis Z1.

[0084] The front lens system Gun1 has positive refractive power. The rear lens system Gun2 has a lens surface that is concave toward the image plane near the optical axis and convex toward the image plane in the peripheral portion on the side closest to the image plane. It is desirable that the front lens system Gun1 is composed of a plurality of lenses and the rear lens system Gun2 is composed of a single lens.

[0085] like Figures 2 to 9 as well as Fig.13 As shown in the configuration example, for example, the imaging lens 300 according to the present embodiment is substantially composed of six lenses, in which the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5 and the sixth lens L6 are sequentially arranged from the object side to the image plane side. In the case where the six lenses are used as a whole for the configuration in this manner, it is desirable that the front lens system Gun1 includes the first to fifth lenses L1 to L5, and the rear lens system Gun2 includes the sixth lens L6. In addition, in this case, the first lens L1 preferably has a positive refractive power near the optical axis. The second lens L2 preferably has a positive or negative refractive power near the optical axis. The third lens L3 preferably has a negative refractive power near the optical axis. The fourth lens L4 preferably has a negative refractive power near the optical axis. The fifth lens L5 preferably has a positive or negative refractive power near the optical axis. The sixth lens L6 preferably has a positive or negative refractive power near the optical axis. The sixth lens L6 preferably has an aspherical shape in which the lens surface on the image side is concave toward the image side in the vicinity of the optical axis and is convex toward the image side in the peripheral portion.

[0086] In addition, if Figures 9 to 12In the configuration example shown in , for example, the imaging lens 300 according to the embodiment may be basically configured by seven lenses, wherein the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, and the seventh lens L7 are arranged in order from the object side to the image plane side. In the case where the seven lenses are used as a whole for the configuration in this manner, it is desirable that the front lens system Gun1 includes the first to sixth lenses L1 to L6, and the rear lens system Gun2 includes the seventh lens L7. In addition, in this case, the first lens L1 preferably has a positive refractive power near the optical axis. The second lens L2 preferably has a positive refractive power near the optical axis. The third lens L3 preferably has a negative refractive power near the optical axis. The fourth lens L4 preferably has a positive or negative refractive power near the optical axis. The fifth lens L5 preferably has a negative refractive power near the optical axis. The sixth lens L6 preferably has a positive or negative refractive power near the optical axis. The seventh lens L7 preferably has a positive or negative refractive power near the optical axis. The seventh lens L7 preferably has an aspherical shape in which a lens surface on the image side is concave toward the image side in the vicinity of the optical axis and is convex toward the image side in a peripheral portion.

[0087] In addition, it is desirable that the imaging lens 300 according to the embodiment of the present disclosure also satisfies predetermined conditional expressions and the like described later.

[0088] <3. Functions and Effects>

[0089] Next, the action and effect of the imaging lens 300 according to the embodiment of the present disclosure will be described. In addition, a description is given of a more desirable configuration in the imaging lens 300 according to the embodiment of the present disclosure.

[0090] It should be noted that the effects described here are merely illustrative and not restrictive, and other effects may be present.

[0091] In the imaging lens 300 according to the embodiment, the front lens system Gun1 and the rear lens system Gun2 arranged in order from the object side to the image plane side are optimized in configuration to accommodate the imaging element 301 of a large element size and have a small size for the optical system and various aberrations are well corrected.

[0092] In the imaging lens 300 according to the embodiment, as described later, it is desirable to perform optimization of the refractive power arrangement, optimization of the lens geometry that effectively uses the aspherical surface, optimization of the lens material, etc. Thus, it is possible to provide a high-performance imaging lens 300 having a small size for the optical system, which corresponds to the imaging element 301 having a large element size, has a small size for the optical system, and various aberrations are well corrected.

[0093] In the imaging lens 300 according to the embodiment, the configuration such as the refractive power configuration is optimized, and in order to be able to be operated by the operation unit 302 ( Figure 1 ) while generating distortion aberration within a predetermined range (conditional expression (2)) of correction, while correcting other aberrations in a well-balanced manner.

[0094] According to the imaging apparatus of the embodiment, distortion aberration generated by the imaging lens 300 is corrected by the arithmetic unit 302 , thus making it possible to accommodate a high-pixel imaging element 301 of a large element size and achieve size reduction of the imaging apparatus as a whole.

[0095] In the imaging lens 300 according to the embodiment, the lens surface of the rear lens system Gun2 on the side closest to the image plane is concave toward the image plane side near the optical axis and is convex toward the image plane side in the peripheral part, thereby making it possible to suppress the incident angle of light emitted from the lens surface on the image plane IMG.

[0096] For the imaging lens 300 according to the embodiment, it is desirable to satisfy the following conditional expressions (1) and (2). Fig.14 The parameter Gun2R2 in the conditional expression (1) is shown (sag6-sag10) Overview.

[0097] 1.0<Gun2R2 (sag6-sag10) / (TTL / 2Y)<2.8......(1)

[0098] 5.0(%)<OD MAX <20.0(%)......(2)

[0099] in

[0100] Gun2R2 (sag6-sag10) It represents the distance between two points parallel to the optical axis, on the lens surface closest to the image plane of the rear lens system, between the point where the principal ray intersects with 60% of the image height and the point where the principal ray intersects with 100% of the image height (unit: "mm").

[0101] TTL represents the distance from the vertex of the lens surface on the side closest to the object of the front lens system to the image plane on the optical axis.

[0102] 2Y represents the diagonal length of the imaging element, and

[0103] OD MAX It represents the maximum value of the distortion aberration within the imaging area generated by the imaging lens.

[0104] Conditional expression (1) defines the ratio between the distance between two points on the lens surface on the side closest to the image plane of the rear lens system Gun2, which intersects with the principal ray of 60% image height and the point intersecting with the principal ray of 100% image height, and the distance on the optical axis from the vertex of the lens surface on the side closest to the object of the front lens system Gun1 to the image plane, and the diagonal length of the imaging element 301. In addition, the above conditional expression (2) defines the maximum value of distortion aberration within the imaging area of ​​the imaging lens 300. Satisfying conditional expressions (1) and (2) makes it possible to ensure a small size and good performance.

[0105] Exceeding the upper limit of conditional expression (1) increases the distance between the two points on the lens surface on the side closest to the image plane of the rear lens system Gun2, where the main ray intersects with 60% of the image height and the point where the main ray intersects with 100% of the image height. In this case, the refractive power for incident light is enhanced, making it possible to achieve size reduction, although the processing difficulty in lens molding increases, which helps correct off-axis coma. Falling below the lower limit of conditional expression (1) reduces the distance between the two points on the lens surface on the side closest to the image plane of the rear lens system Gun2, where the main ray intersects with 60% of the image height and the point where the main ray intersects with 100% of the image height. In this case, the refractive power for incident light is weakened, making it difficult to achieve size reduction due to the increase in the total length of the lens.

[0106] In addition, exceeding the upper limit of conditional expression (2) results in an excessively large amount of distortion. Although there is an advantage in shortening the total length, it becomes difficult to correct other off-axis aberrations in a well-balanced manner. Falling below the lower limit of conditional expression (2) requires correction of distortion in the imaging lens 300, thus making it difficult to achieve the shortening of the total length required for the imaging device.

[0107] Note that in order to better achieve the above-mentioned effect of the conditional expression (1), it is more desirable to set the numerical range of the conditional expression (1) as follows: conditional expression (1)′.

[0108] 1.1<Gun2R2 (sag6-sag10) / (TTL / 2Y)<2.6......(1)'

[0109] In addition, it is desirable that the imaging lens 300 according to the embodiment satisfies the following conditional expression (3):

[0110] 1.7<f / Gun1R1<2.8......(3)

[0111] in

[0112] f represents the focal length of the entire lens system, and

[0113] Gun1R1 represents the radius of curvature of the lens surface of the front lens system Gun1 on the side closest to the object.

[0114] Conditional expression (3) defines the ratio between the focal length of the entire system and the radius of curvature of the lens surface on the side of the front lens system Gun1 closest to the object. Satisfying conditional expression (3) makes it possible to ensure a small size and good performance. Exceeding the upper limit of conditional expression (3) results in a longer focal length of the entire system and a weakening of the refractive power for incident light, making it difficult to achieve size reduction due to the increase in the total length of the lens. Falling below the lower limit of conditional expression (3) shortens the focal length of the entire system and enhances the refractive power for incident light, making it possible to achieve size reduction, although the sensitivity during lens assembly increases, which helps to correct various aberrations.

[0115] Note that in order to better achieve the above-described effect of the conditional expression (3), it is more desirable to set the numerical range of the conditional expression (3) to the following conditional expression (3)′.

[0116] 1.9<f / Gun1R1<2.6......(3)'

[0117] In addition, it is desirable that the imaging lens 300 according to the embodiment satisfies the following conditional expression (4):

[0118] 2.2<f / Gun2R2<3.8......(4)

[0119] in,

[0120] f represents the focal length of the entire lens system, and

[0121] Gun2R2 represents the curvature radius of the lens surface of the rear lens system Gun2 on the side closest to the image plane.

[0122] Conditional expression (4) defines the ratio between the focal length of the entire system and the radius of curvature of the lens surface on the side closest to the image plane of the rear lens system Gun2. Satisfying conditional expression (4) makes it possible to ensure a small size and good performance. Exceeding the upper limit of conditional expression (4) results in a longer focal length of the entire system and a weakening of the refractive power for incident light, making it difficult to achieve size reduction due to the increase in the total length of the lens. Falling below the lower limit of conditional expression (4) shortens the focal length of the entire system and enhances the refractive power for incident light, making it possible to achieve size reduction, although the sensitivity during lens assembly increases, which helps to correct various aberrations.

[0123] Note that in order to better achieve the above-described effect of the conditional expression (4), it is more desirable to set the numerical range of the conditional expression (4) to the following conditional expression (4)′.

[0124] 2.4<f / Gun2R2<3.5......(4)'

[0125] In addition, it is desirable that the imaging lens 300 according to the embodiment satisfies the following conditional expression (5):

[0126] 17.3<νd(L4)<61.7......(5)

[0127] in

[0128] νd(L4) denotes the Abbe number of fourth lens L4 with respect to the d-line.

[0129] The above conditional expression (5) defines the Abbe number of the fourth lens L4. Satisfying the conditional expression (5) makes it possible to ensure good performance. Exceeding the upper limit of the conditional expression (5) results in the refractive index of the F line and the g line not being sufficiently obtained, thereby making it difficult to suppress axial chromatic aberration. Falling below the lower limit of the conditional expression (5) results in the refractive index of the F line and the g line being too large, thereby making it difficult to suppress axial chromatic aberration.

[0130] In addition, it is desirable that the imaging lens 300 according to the embodiment further satisfies the following conditional expression (6):

[0131] 20.2<νd(L5)<61.3......(6)

[0132] in

[0133] νd(L5) denotes the Abbe number of the fifth lens L5 with respect to the d-line.

[0134] Conditional expression (6) defines the Abbe number of the fifth lens L5. Satisfying conditional expression (6) makes it possible to ensure good performance. Exceeding the upper limit of conditional expression (6) results in the refractive index of the F line and the g line not being sufficiently obtained, thus making it difficult to suppress axial chromatic aberration. Falling below the lower limit of conditional expression (6) results in the refractive index of the F line and the g line being too large, thus making it difficult to suppress axial chromatic aberration.

[0135] In addition, it is desirable that the imaging lens 300 according to the embodiment further satisfies the following conditional expression (7):

[0136] 23.2<νd(L6)<61.3......(7)

[0137] in

[0138] νd(L6) denotes the Abbe number of sixth lens L6 with respect to the d-line.

[0139] The above conditional expression (7) defines the Abbe number of the sixth lens L6. Satisfying the conditional expression (7) makes it possible to ensure good performance. Exceeding the upper limit of the conditional expression (7) results in the refractive index of the F line and the g line not being sufficiently obtained, thereby making it difficult to suppress axial chromatic aberration. Falling below the lower limit of the conditional expression (7) results in the refractive index of the F line and the g line being too large, thereby making it difficult to suppress axial chromatic aberration.

[0140] Furthermore, in the imaging lens 300 according to the embodiment, the aperture stop St is preferably provided between the lens surface on the object side of the first lens L1 and the lens surface on the image plane side of the first lens L1, between the lens surface on the image plane side of the first lens L1 and the lens surface on the image plane side of the second lens L2, or between the lens surface on the image plane side of the second lens L2 and the lens surface on the image plane side of the third lens L3. In the case where the aperture stop St is provided between the lens surface on the object side of the first lens L1 and the lens surface on the image plane side of the first lens L1, propagation of light incident on the first lens L1 is suppressed, thereby making it possible to achieve both aberration correction and improvement of stray light caused by the first lens L1. In the case where the aperture stop St is provided between the lens surface on the image plane side of the first lens L1 and the lens surface on the image plane side of the second lens L2, propagation of light incident on the second lens L2 is suppressed, thereby making it possible to achieve both aberration correction and improvement of stray light caused by the second lens L2.

[0141] <4. Specific application examples of imaging equipment>

[0142] Next, an example in which the imaging lens 300 according to the present embodiment is applied to an imaging device is described.

[0143] Fig. 27 and Fig.28 Each shows a configuration example of an imaging device to which the imaging lens 300 according to the present embodiment is applied. The configuration example is an example of a mobile terminal device (for example, a mobile information terminal or a mobile phone terminal) having an imaging device. The mobile terminal device includes a substantially rectangular housing 201. A display unit 202 and a front camera unit 203 are provided on the front surface side of the housing 201 ( Fig. 27 A main camera unit 204 and a camera flash 205 are provided on the rear surface side of the housing 201 ( Fig.28 ). In addition, operation buttons 206 and 207 are provided on one side of the housing 201.

[0144] For example, the display unit 202 is a touch panel that senses a contact state with a surface to allow various operations. Thus, the display unit 202 has a display function that displays various information and an input function that allows a user to perform input operations. The display unit 202 displays an operation state and various data, such as an image captured by the front camera unit 203 or the main camera unit 204. Note that various operations can be performed from the operation buttons 206 and 207.

[0145] For example, the imaging lens 300 of this embodiment can be Fig. 27 and Fig.28 The camera module lens is used as an imaging device (front camera unit 203 or main camera unit 204) in the portable terminal device shown in the figure. When used as such a camera module lens, an imaging element 301 such as a CCD or a CMOS is arranged near the image plane IMG of the imaging lens 300, and the imaging element 301 outputs an imaging signal (image signal) corresponding to the optical image formed by the imaging lens 300. In this case, Figure 2 As shown in FIG. 1 , optical components such as sealing glass SG and various filters for protecting imaging elements may be disposed between the final lens and the image plane IMG. In addition, optical components such as sealing glass SG and various filters may be disposed at any position between the final lens and the image plane IMG.

[0146] Note that the imaging lens according to the present embodiment is not limited to application to the above-mentioned mobile terminal device, but can also be applied to imaging lenses of other electronic devices, such as digital still cameras and digital video cameras. The imaging lens 300 can also be applied to general small-sized imaging devices in which solid-state imaging devices such as CCD and CMOS are used, such as optical sensors, mobile module cameras, network cameras, etc. In addition, the imaging lens 300 according to the present embodiment can also be applied to surveillance cameras, etc.

[0147] <5. Numerical examples of lenses>

[0148] Next, a specific numerical working example of the imaging lens 300 according to the present embodiment is described.

[0149] Here, numerical working examples are described in which specific numerical values ​​are applied to Figures 2 to 13 1 to 12 of the respective configuration examples are shown in FIG.

[0150] It should be noted that the meanings of the various symbols indicated in the following table and the specification are as follows. "Si" represents the number of the i-th surface assigned in ascending order from the side closest to the object. "Ri" represents the paraxial curvature radius value of the i-th surface (mm). "Di" represents the value of the interval between the i-th surface and the (i+1)-th surface on the optical axis (mm). "Ndi" represents the value of the refractive index of the material of the optical element having the i-th surface on the d-line (wavelength 587.6nm). "νdi" represents the value of the Abbe number of the material of the optical element having the i-th surface on the d-line. The part where the value of "Ri" is "∞" represents a plane or a virtual surface. "Li" represents the properties of the surface. In "Li", for example, "L1R1" represents the lens surface of the first lens L1 on the object side, and "L1R2" represents the lens surface of the first lens L1 on the image side. Similarly, in “Li”, “L2R1” represents the lens surface of the second lens L2 on the object side, and “L2R2” represents the lens surface of the second lens L2 on the image side. The same applies to the other lens surfaces.

[0151] In addition, a portion of the lenses used in each numerical working example has a lens surface configured by an aspherical surface. The aspherical surface shape is defined by the following expression. Note that in each table showing aspherical surface coefficients described below, "Ei" represents an exponential expression with 10 as the base, that is, "10 -i ”, for example, “0.12345E-05” means “0.12345×10 -5 ”.

[0152] (Aspherical expression)

[0153] Z=C·h 2 / {1+(1-(1+K)·C 2 ·h 2 ) 1 / 2}+ΣAn·h n

[0154] (n=integer greater than or equal to 3)

[0155] in,

[0156] Z represents the depth of the aspherical surface,

[0157] C represents the paraxial curvature equal to 1 / R,

[0158] h is the length from the optical axis to the lens surface,

[0159] K represents the eccentricity (second-order aspheric surface coefficient), and

[0160] An represents the nth order aspheric surface coefficient.

[0161] (Overview of Numerical Examples)

[0162] Each of the imaging lenses 1 to 12 to which the following numerical examples are applied has a configuration satisfying the above-described basic lens configuration. That is, each of the imaging lenses 1 to 12 is composed of a front lens system Gun1 and a rear lens system Gun2 in order from the object side to the image plane side along the optical axis Z1.

[0163] The aperture stop St is arranged between the lens surface on the object side of the first lens L1 and the lens surface on the image side of the first lens L1, between the lens surface on the image side of the first lens L1 and the lens surface on the image side of the second lens L2, or between the lens surface on the image side of the second lens L2 and the lens surface on the image side of the third lens L3.

[0164] (Imaging lenses 1 to 8 and 12)

[0165] Imaging lenses 1 to 8 and 12 ( Figures 2 to 9 and 13) are each basically composed of six lenses, wherein the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5 and the sixth lens L6 are arranged in order from the object side to the image side. The front lens system Gun1 includes the first to fifth lenses L1 to L5. The rear lens system Gun2 includes the sixth lens L6.

[0166] In imaging lenses 1 to 8 and 12, the first lens L1 has positive refractive power near the optical axis. The second lens L2 has positive or negative refractive power near the optical axis. The third lens L3 has negative refractive power near the optical axis. The fourth lens L4 has negative refractive power near the optical axis. The fifth lens L5 has positive or negative refractive power near the optical axis. The sixth lens L6 has positive or negative refractive power near the optical axis. The sixth lens L6 has an aspherical shape in which the lens surface on the image side is concave toward the image side near the optical axis and convex toward the image side in the peripheral portion.

[0167] In the imaging lenses 1 to 8 and 12 , seal glass SG is provided between the sixth lens L6 and the image plane IMG.

[0168] (Imaging lenses 9 to 11)

[0169] Imaging lenses 9 to 11 ( Figures 9 to 12 ) are each basically configured by seven lenses, wherein the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6 and the seventh lens L7 are arranged in order from the object side to the image side. The front lens system Gun1 includes the first to sixth lenses L1 to L6. The rear lens system Gun2 includes the seventh lens L7.

[0170] In imaging lenses 9 to 11, the first lens L1 has positive refractive power near the optical axis. The second lens L2 has positive refractive power near the optical axis. The third lens L3 has negative refractive power near the optical axis. The fourth lens L4 has positive or negative refractive power near the optical axis. The fifth lens L5 has negative refractive power near the optical axis. The sixth lens L6 has positive or negative refractive power near the optical axis. The seventh lens L7 has positive or negative refractive power near the optical axis. The seventh lens L7 has an aspherical shape in which the lens surface on the image side is concave toward the image side near the optical axis and convex toward the image side in the peripheral portion.

[0171] In the imaging lenses 9 to 11 , seal glass SG is provided between the seventh lens L7 and the image plane IMG.

[0172] [Numerical Example 1]

[0173] Table 1 shows the Figure 2 The imaging lens 1 shown is basic lens data of Numerical Example 1 to which specific numerical values ​​are applied. In the imaging lens 1 of Numerical Example 1, the second lens L2 has negative refractive power near the optical axis. The fifth lens L5 has positive refractive power near the optical axis. The sixth lens L6 has negative refractive power near the optical axis.

[0174] In the imaging lens 1 according to Numerical Example 1, both surfaces of each of the first lens L1 to the sixth lens L6 have an aspherical shape. Tables 2 and 3 show coefficient values ​​representing the aspherical shape.

[0175] In addition, Table 4 shows values ​​of focal length F, F number, total length, and half angle of view ω of the entire lens system in the imaging lens 1 according to Numerical Example 1. Table 5 shows values ​​of respective focal lengths of first lens L1 to sixth lens L6 .

[0176] [Table 1]

[0177]

[0178]

[0179] [Table 2]

[0180]

[0181]

[0182] [Table 3]

[0183]

[0184] [Table 4]

[0185]

[0186] [Table 5]

[0187]

[0188]

[0189] Fig.15 Various aberrations in the above-mentioned numerical example 1 are shown. Fig.15 Spherical aberration, astigmatism (field curvature), and distortion are shown as various aberrations. Each of these aberration diagrams shows the aberration with the d-line (587.56nm) as the reference wavelength. The spherical aberration diagram and the astigmatism aberration diagram also show aberrations with respect to the g-line (435.84nm) and the C-line (656.27nm). In the astigmatism aberration diagram, S represents the value on the sagittal image plane, and T represents the value on the tangential image plane. The same applies to the aberration diagrams in other subsequent numerical examples.

[0190] As can be understood from each aberration diagram, it is apparent that the imaging lens 1 according to Numerical Example 1 is adaptable to a large element size and has excellent optical performance due to a small size for the optical system and various aberrations are well corrected.

[0191] [Numerical Example 2]

[0192] Table 6 shows the Figure 3 The imaging lens 2 shown applies the basic lens data of Numerical Example 2 of specific numerical values. In the imaging lens 2 of Numerical Example 2, the second lens L2 has a negative refractive power near the optical axis. The fifth lens L5 has a positive refractive power near the optical axis. The sixth lens L6 has a negative refractive power near the optical axis.

[0193] In the imaging lens 2 according to Numerical Example 2, both surfaces of each of the first lens L1 to the sixth lens L6 have an aspherical shape. Tables 7 and 8 show coefficient values ​​representing the aspherical shape.

[0194] In addition, Table 9 shows values ​​of focal length F, F number, total length, and half angle of view ω of the entire lens system in the imaging lens 2 according to Numerical Example 2. Table 10 shows values ​​of respective focal lengths of first lens L1 to sixth lens L6 .

[0195] [Table 6]

[0196]

[0197]

[0198] [Table 7]

[0199]

[0200]

[0201] [Table 8]

[0202]

[0203] [Table 9]

[0204]

[0205] [Table 10]

[0206]

[0207]

[0208] Fig.16 Various aberrations in the above-mentioned Numerical Example 2 are shown.

[0209] As can be understood from each aberration diagram, it is apparent that the imaging lens 2 according to Numerical Example 2 is adaptable to a large element size and has excellent optical performance due to a small size for the optical system and various aberrations are well corrected.

[0210] [Numerical Example 3]

[0211] Table 11 shows the Figure 4 The imaging lens 3 shown applies basic lens data of Numerical Example 3 of specific numerical values. In the imaging lens 3 of Numerical Example 3, the second lens L2 has positive refractive power near the optical axis. The fifth lens L5 has positive refractive power near the optical axis. The sixth lens L6 has negative refractive power near the optical axis.

[0212] In the imaging lens 3 according to Numerical Example 3, both surfaces of each of the first lens L1 to the sixth lens L6 have an aspherical shape. Table 12 and Table 13 show coefficient values ​​representing the aspherical shape.

[0213] In addition, Table 14 shows values ​​of focal length F, F number, total length, and half angle of view ω of the entire lens system in the imaging lens 3 according to Numerical Example 3. Table 15 shows values ​​of respective focal lengths of the first lens L1 to the sixth lens L6 .

[0214] [Table 11]

[0215]

[0216]

[0217] [Table 12]

[0218]

[0219] [Table 13]

[0220]

[0221] [Table 14]

[0222]

[0223] [Table 15]

[0224]

[0225] Fig.17 Various aberrations in the above-mentioned Numerical Example 3 are shown.

[0226] As can be understood from each aberration diagram, it is apparent that the imaging lens 3 according to Numerical Example 3 is adaptable to a large element size and has excellent optical performance due to a small size for the optical system and various aberrations are well corrected.

[0227] [Numerical Example 4]

[0228] Table 16 shows the Figure 5 The imaging lens 4 shown is applied to the basic lens data of the numerical example 4 of specific numerical values. In the imaging lens 4 of the numerical example 4, the second lens L2 has positive refractive power near the optical axis. The fifth lens L5 has positive refractive power near the optical axis. The sixth lens L6 has negative refractive power near the optical axis.

[0229] In the imaging lens 4 according to Numerical Example 4, both surfaces of each of the first lens L1 to the sixth lens L6 have an aspherical shape. Table 17 and Table 18 show coefficient values ​​representing the aspherical shape.

[0230] In addition, Table 19 shows values ​​of focal length F, F number, total length, and half angle of view ω of the entire lens system in the imaging lens 4 according to Numerical Example 4. Table 20 shows values ​​of respective focal lengths of the first lens L1 to the sixth lens L6.

[0231] [Table 16]

[0232]

[0233] [Table 17]

[0234]

[0235]

[0236] [Table 18]

[0237]

[0238]

[0239] [Table 19]

[0240]

[0241] [Table 20]

[0242]

[0243] Fig.18 Various aberrations in the above-mentioned numerical example 4 are shown.

[0244] As can be understood from each aberration diagram, it is apparent that the imaging lens 4 according to Numerical Example 4 is adaptable to a large element size and has excellent optical performance due to a small size for the optical system and various aberrations are well corrected.

[0245] [Numerical Example 5]

[0246] Table 21 shows the Figure 6 The imaging lens 5 shown is basic lens data of Numerical Example 5 with specific numerical values. In the imaging lens 5 of Numerical Example 5, the second lens L2 has positive refractive power near the optical axis. The fifth lens L5 has positive refractive power near the optical axis. The sixth lens L6 has negative refractive power near the optical axis.

[0247] In the imaging lens 5 according to Numerical Example 5, both surfaces of each of the first lens L1 to the sixth lens L6 have an aspherical shape. Table 22 and Table 23 show coefficient values ​​representing the aspherical shape.

[0248] In addition, Table 24 shows values ​​of focal length F, F number, total length, and half angle of view ω of the entire lens system in the imaging lens 5 according to Numerical Example 5. Table 25 shows values ​​of respective focal lengths of the first lens L1 to the sixth lens L6.

[0249] [Table 21]

[0250]

[0251] [Table 22]

[0252]

[0253]

[0254] [Table 23]

[0255]

[0256]

[0257] [Table 24]

[0258]

[0259] [Table 25]

[0260]

[0261] Fig.19 Various aberrations in the above-mentioned numerical example 5 are shown.

[0262] As can be understood from each aberration diagram, it is apparent that the imaging lens 5 according to Numerical Example 5 is adaptable to a large element size and has excellent optical performance due to a small size for the optical system and various aberrations are well corrected.

[0263] [Numerical Example 6]

[0264] Table 26 shows the Figure 7 The imaging lens 6 shown applies the basic lens data of the numerical example 6 of specific numerical values. In the imaging lens 6 of the numerical example 6, the second lens L2 has a positive refractive power near the optical axis. The fifth lens L5 has a positive refractive power near the optical axis. The sixth lens L6 has a negative refractive power near the optical axis.

[0265] In the imaging lens 6 according to Numerical Example 6, both surfaces of each of the first lens L1 to the sixth lens L6 have an aspherical shape. Table 27 and Table 28 show coefficient values ​​representing the aspherical shape.

[0266] In addition, Table 29 shows values ​​of focal length F, F number, total length, and half angle of view ω of the entire lens system in the imaging lens 6 according to Numerical Example 6. Table 30 shows values ​​of respective focal lengths of the first lens L1 to the sixth lens L6.

[0267] [Table 26]

[0268]

[0269]

[0270] [Table 27]

[0271]

[0272]

[0273] [Table 28]

[0274]

[0275] [Table 29]

[0276]

[0277] [Table 30]

[0278]

[0279] Fig. 20 Various aberrations in the above-mentioned Numerical Example 6 are shown.

[0280] As can be understood from each aberration diagram, it is apparent that the imaging lens 6 according to Numerical Example 6 is adaptable to a large element size and has excellent optical performance due to a small size for the optical system and various aberrations are well corrected.

[0281] [Numerical Example 7]

[0282] Table 31 shows the Figure 8 The imaging lens 7 shown applies the basic lens data of the numerical example 7 of specific numerical values. In the imaging lens 7 of the numerical example 7, the second lens L2 has a negative refractive power near the optical axis. The fifth lens L5 has a positive refractive power near the optical axis. The sixth lens L6 has a negative refractive power near the optical axis.

[0283] In the imaging lens 7 according to Numerical Example 7, both surfaces of each of the first lens L1 to the sixth lens L6 have an aspherical shape. Table 32 and Table 33 show coefficient values ​​representing the aspherical shape.

[0284] In addition, Table 34 shows values ​​of focal length F, F number, total length, and half angle of view ω of the entire lens system in imaging lens 7 according to Numerical Example 7. Table 35 shows values ​​of respective focal lengths of first lens L1 to sixth lens L6.

[0285] [Table 31]

[0286]

[0287]

[0288] [Table 32]

[0289]

[0290]

[0291] [Table 33]

[0292]

[0293] [Table 34]

[0294]

[0295] [Table 35]

[0296]

[0297] Fig.21 Various aberrations in the above-mentioned numerical example 7 are shown.

[0298] As can be understood from each aberration diagram, it is apparent that the imaging lens 7 according to Numerical Example 7 is adaptable to a large element size and has excellent optical performance due to a small size for the optical system and various aberrations are well corrected.

[0299] [Numerical Example 8]

[0300] Table 36 shows the Fig. 9 The imaging lens 8 shown applies the basic lens data of the numerical example 8 of the specific numerical value. In the imaging lens 8 of the numerical example 8, the second lens L2 has a positive refractive power near the optical axis. The fifth lens L5 has a negative refractive power near the optical axis. The sixth lens L6 has a positive refractive power near the optical axis.

[0301] In the imaging lens 8 according to Numerical Example 8, both surfaces of each of the first lens L1 to the sixth lens L6 have an aspherical shape. Table 37 and Table 38 show coefficient values ​​representing the aspherical shape.

[0302] In addition, Table 39 shows values ​​of focal length F, F number, total length, and half angle of view ω of the entire lens system in imaging lens 8 according to Numerical Example 8. Table 40 shows values ​​of respective focal lengths of first lens L1 to sixth lens L6.

[0303] [Table 36]

[0304]

[0305] [Table 37]

[0306]

[0307]

[0308] [Table 38]

[0309]

[0310]

[0311] [Table 39]

[0312]

[0313] [Table 40]

[0314]

[0315] Fig. 22 Various aberrations in the above-mentioned Numerical Example 8 are shown.

[0316] As can be understood from each aberration diagram, it is apparent that the imaging lens 8 according to Numerical Example 8 is adaptable to a large element size and has excellent optical performance due to a small size for the optical system and various aberrations are well corrected.

[0317] [Numerical Example 9]

[0318] Table 41 shows the Fig.10 The imaging lens 9 shown applies the basic lens data of the numerical example 9 of specific numerical values. In the imaging lens 9 of the numerical example 9, the fourth lens L4 has a positive refractive power near the optical axis. The sixth lens L6 has a positive refractive power near the optical axis. The seventh lens L7 has a negative refractive power near the optical axis.

[0319] In the imaging lens 9 according to Numerical Example 9, both surfaces of each of the first lens L1 to the seventh lens L7 have an aspherical shape. Table 42 and Table 43 show coefficient values ​​representing the aspherical shape.

[0320] In addition, Table 44 shows values ​​of focal length F, F number, total length, and half angle of view ω of the entire lens system in the imaging lens 9 according to Numerical Example 9. Table 45 shows values ​​of respective focal lengths of the first lens L1 to the seventh lens L7.

[0321] [Table 41]

[0322]

[0323] [Table 42]

[0324]

[0325]

[0326] [Table 43]

[0327]

[0328]

[0329] [Table 44]

[0330]

[0331] [Table 45]

[0332]

[0333] Fig.23 Various aberrations in the above-mentioned numerical example 9 are shown.

[0334] As can be understood from each aberration diagram, it is apparent that the imaging lens 9 according to Numerical Example 9 is adaptable to a large element size and has excellent optical performance due to a small size for the optical system and various aberrations are well corrected.

[0335] [Numerical Example 10]

[0336] Table 46 shows Fig.11 The imaging lens 10 shown is applicable to basic lens data of Numerical Example 10 of specific numerical values. In the imaging lens 10 of Numerical Example 10, the fourth lens L4 has negative refractive power near the optical axis. The sixth lens L6 has negative refractive power near the optical axis. The seventh lens L7 has negative refractive power near the optical axis.

[0337] In the imaging lens 10 according to Numerical Example 10, both surfaces of each of the first lens L1 to the seventh lens L7 have an aspherical shape. Tables 47 and 48 show coefficient values ​​representing the aspherical shape.

[0338] In addition, Table 49 shows values ​​of focal length F, F number, total length, and half angle of view ω of the entire lens system in the imaging lens 10 according to Numerical Example 10. Table 50 shows values ​​of respective focal lengths of first lens L1 to seventh lens L7.

[0339] [Table 46]

[0340]

[0341]

[0342] [Table 47]

[0343]

[0344] [Table 48]

[0345]

[0346]

[0347] [Table 49]

[0348]

[0349]

[0350] [Table 50]

[0351]

[0352] Fig.24 Various aberrations in the above-mentioned numerical example 10 are shown.

[0353] As can be understood from each aberration diagram, it is apparent that the imaging lens 10 according to Numerical Example 10 is adaptable to a large element size and has excellent optical performance due to a small size for the optical system and various aberrations are well corrected.

[0354] [Numerical Example 11]

[0355] Table 51 shows Fig.12 The imaging lens 11 shown applies the basic lens data of the numerical example 11 of specific numerical values. In the imaging lens 11 of the numerical example 11, the fourth lens L4 has a negative refractive power near the optical axis. The sixth lens L6 has a negative refractive power near the optical axis. The seventh lens L7 has a positive refractive power near the optical axis.

[0356] In the imaging lens 11 according to Numerical Example 11, both surfaces of each of the first lens L1 to the seventh lens L7 have an aspherical shape. Table 52 and Table 53 show coefficient values ​​representing the aspherical shape.

[0357] In addition, Table 54 shows values ​​of focal length F, F number, total length, and half angle of view ω of the entire lens system in the imaging lens 11 according to Numerical Example 11. Table 55 shows values ​​of respective focal lengths of first lens L1 to seventh lens L7.

[0358] [Table 51]

[0359]

[0360]

[0361] [Table 52]

[0362]

[0363]

[0364] [Table 53]

[0365]

[0366]

[0367] [Table 54]

[0368]

[0369] [Table 55]

[0370]

[0371] Fig.25 Various aberrations in the above-mentioned numerical example 11 are shown.

[0372] As can be understood from each aberration diagram, it is apparent that the imaging lens 11 according to Numerical Example 11 is adaptable to a large element size and has excellent optical performance due to a small size for the optical system and various aberrations are well corrected.

[0373] [Numerical Example 12]

[0374] Table 56 shows the Fig.13 The imaging lens 12 shown applies the basic lens data of the numerical example 12 of specific numerical values. In the imaging lens 12 of the numerical example 12, the second lens L2 has a positive refractive power near the optical axis. The fifth lens L5 has a positive refractive power near the optical axis. The sixth lens L6 has a negative refractive power near the optical axis.

[0375] In the imaging lens 12 according to Numerical Example 12, both surfaces of each of the first lens L1 to the sixth lens L6 have an aspherical shape. Table 57 and Table 58 show coefficient values ​​representing the aspherical shape.

[0376] In addition, Table 59 shows values ​​of focal length F, F number, total length, and half angle of view ω of the entire lens system in the imaging lens 12 according to Numerical Example 12. Table 60 shows values ​​of respective focal lengths of first lens L1 to sixth lens L6.

[0377] [Table 56]

[0378]

[0379] [Table 57]

[0380]

[0381]

[0382] [Table 58]

[0383]

[0384] [Table 59]

[0385]

[0386] [Table 60]

[0387]

[0388] Fig.26 Various aberrations in the above-mentioned numerical example 12 are shown.

[0389] As can be understood from each aberration diagram, it is apparent that the imaging lens 12 according to Numerical Example 12 is adaptable to a large element size and has excellent optical performance due to a small size for the optical system and various aberrations are well corrected.

[0390] [Other numerical data of each embodiment]

[0391] Tables 61 to 62 summarize the values ​​related to each of the above-mentioned conditional expressions for each numerical example. As can be understood from Tables 61 to 62, the value of each numerical example of each conditional expression falls within the range of the corresponding numerical value.

[0392] [Table 61]

[0393]

[0394] [Table 62]

[0395]

[0396]

[0397] <6. Application Examples>

[0398] [6.1 First application example]

[0399] The technology according to the present disclosure can be applied to various products. For example, the technology according to the present disclosure can be implemented as a device to be installed on a movable body of any kind of automobile, electric vehicle, hybrid electric vehicle, motorcycle, bicycle, personal mobile device, airplane, drone, ship, robot, construction machinery, agricultural machinery (tractor), etc.

[0400] Fig.29 7000 is a block diagram showing an example of a schematic configuration of a vehicle control system 7000 as an example of a mobile body control system to which the technology of the embodiment of the present invention can be applied. The vehicle control system 7000 includes a plurality of electronic control units connected to each other via a communication network 7010. Fig.29 In the example shown, the vehicle control system 7000 includes 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 that connects the plurality of control units to each other may be, for example, an in-vehicle communication network conforming to any standard, such as a controller area network (CAN), a local interconnect network (LIN), a local area network (LAN), FlexRay (registered trademark), and the like.

[0401] Each control unit includes: a microcomputer that performs arithmetic processing according to various programs; a storage part that stores programs executed by the microcomputer, parameters for various operations, etc.; and a drive circuit that drives various control object devices. Each control unit also includes: a network interface (I / F) for communicating with other control units via the communication network 7010; and a communication I / F for communicating with devices, sensors, etc. inside and outside the vehicle through wired communication or radio communication. Fig.29 The functional configuration of the integrated control unit 7600 shown in FIG. 76 includes a microcomputer 7610, a general communication I / F 7620, a dedicated communication I / F 7630, a positioning section 7640, a beacon receiving section 7650, an in-vehicle device I / F 7660, a sound / image output section 7670, an in-vehicle network I / F 7680, and a storage section 7690. Other control units similarly include a microcomputer, a communication I / F, a storage section, and the like.

[0402] The drive system control unit 7100 controls the operation of devices related to the drive system of the vehicle according to various programs. For example, the drive system control unit 7100 has the function of a control device for controlling the following devices: a drive force generating device for generating a vehicle (such as an internal combustion engine, a drive motor, etc.), a drive force transmission mechanism for transmitting the drive force to the wheels, a steering mechanism for adjusting the steering angle of the vehicle, a braking device for generating the braking force of the vehicle, etc. The drive system control unit 7100 may have the function of a control device for an anti-lock braking system (ABS), an electronic stability control (ESC), etc.

[0403] The drive system control unit 7100 is connected to the vehicle state detection part 7110. The vehicle state detection part 7110 includes, for example, at least one of a gyro sensor, an acceleration sensor, and a sensor. The gyro sensor detects the angular velocity of the axial rotational motion of the vehicle body, the acceleration sensor detects the acceleration of the vehicle, and the sensor is used to detect the operation amount of the accelerator pedal, the operation amount of the brake pedal, the steering angle of the steering wheel, the engine speed or the rotation speed of the wheel, etc. The drive system control part 7100 uses the signal input from the vehicle state detection part 7110 to perform calculation processing and control the internal combustion engine, the drive motor, the electric power steering device, the brake device, etc.

[0404] The vehicle body system control unit 7200 controls the operation of various devices provided to the vehicle body according to various programs. For example, the vehicle body system control unit 7200 is used as a control device for a keyless entry system, a smart key system, a power window device, or various lights such as a headlight, a reverse light, a brake light, a turn signal, a fog light, etc. In this case, a signal of a radio wave transmitted from a mobile device as a substitute for a key or various switches may be input to the vehicle body system control unit 7200. The vehicle body system control unit 7200 receives these input radio waves or signals, and controls a door lock device, a power window device, lights, etc. of the vehicle.

[0405] The battery control unit 7300 controls the secondary battery 7310 as a power source for driving the motor according to various programs. For example, information about the battery temperature, the battery output voltage, the amount of charge remaining in the battery, etc. is provided to the battery control unit 7300 from the battery device including the secondary battery 7310. The battery control unit 7300 performs operation processing using these signals, and performs control for adjusting the temperature of the secondary battery 7310 or controlling a cooling device provided to the battery device, etc.

[0406] The vehicle exterior information detection part 7400 detects information outside the vehicle including the vehicle control system 7000. For example, the vehicle exterior information detection part 7400 is connected to at least one of the imaging part 7410 and the vehicle exterior information detection part 7420. The imaging part 7410 includes at least one of a time of flight (ToF) camera, a stereo camera, a monocular camera, an infrared camera, and other cameras. The vehicle exterior information detection part 7420 includes, for example, an environmental sensor for detecting current atmospheric conditions or weather conditions and at least one of a peripheral information detection sensor for detecting another vehicle, an obstacle, a pedestrian, etc. on the periphery of the vehicle including the vehicle control system 7000.

[0407] For example, the environmental sensor may be at least one of a raindrop sensor for detecting rain, a fog sensor for detecting fog, a sunshine sensor for detecting the degree of sunshine, and a snow sensor for detecting snowfall. The peripheral information detection sensor may be at least one of an ultrasonic sensor, a radar device, and a LIDAR device (a light detection and ranging device, or a laser imaging detection and ranging device). The imaging portion 7410 and the vehicle exterior information detection portion 7420 may be provided as independent sensors or devices, respectively, or may be provided as a device integrating multiple sensors or devices.

[0408] Fig.307910 and the vehicle exterior information detection section 7420 are arranged at least one of the positions on the front nose, side mirrors, rear bumper and rear door of the vehicle 7900 and the upper part of the windshield inside the vehicle. The imaging section 7910 arranged on the front nose and the imaging section 7918 arranged on the upper part of the windshield inside the vehicle mainly obtain the image of the front of the vehicle 7900. The imaging sections 7912 and 7914 arranged on the side mirrors mainly obtain the image of the side of the vehicle 7900. The imaging section 7916 arranged on the rear bumper or the rear door mainly obtains the image of the rear of the vehicle 7900. The imaging section 7918 arranged on the upper part of the windshield inside the vehicle is mainly used to detect the front vehicle, pedestrians, obstacles, signals, traffic signs, lanes, etc.

[0409] By the way, Fig.30 An example of the shooting range of each imaging portion 7910, 7912, 7914, and 7916 is described. Imaging range a represents the imaging range of the imaging portion 7910 set to the front nose. Imaging ranges b and c respectively represent the imaging ranges of the imaging portions 7912 and 7914 provided to the side mirrors. Imaging range d represents the imaging range of the imaging portion 7916 set on the rear bumper or the rear door. For example, by superimposing image data imaged by the imaging portions 7910, 7912, 7914, and 7916, a bird's-eye view image of the vehicle 7900 observed from above can be obtained.

[0410] The vehicle exterior information detection parts 7920, 7922, 7924, 7926, 7928 and 7930 provided at the front, rear, side and corner of the vehicle 7900 and the upper part of the windshield inside the vehicle may be, for example, ultrasonic sensors or radar devices. The vehicle exterior information detection parts 7920, 7926 and 7930 provided at the front end of the vehicle 7900, the rear bumper, the rear door of the vehicle 7900 and the upper part of the windshield inside the vehicle may be, for example, LIDAR devices. These vehicle exterior information detection parts 7920 to 7930 are mainly used to detect the front vehicle, pedestrians, obstacles, etc.

[0411] Back to Fig.29, continue to explain. The vehicle exterior information detection part 7400 enables the imaging part 7410 to image the image outside the vehicle and receive the image data. In addition, the vehicle exterior information detection part 7400 receives detection information from the vehicle exterior information detection part 7420 connected to the vehicle exterior information detection part 7400. In the case where the vehicle exterior information detection part 7420 is an ultrasonic sensor, a radar device, or a LIDAR device, the vehicle exterior information detection part 7400 sends ultrasonic waves, electromagnetic waves, etc., and receives information of the received reflected waves. The vehicle exterior information detection part 7400 can also detect objects such as people, vehicles, obstacles, signs, and text on the road surface based on the received information, or detect the distance therebetween. The vehicle exterior information detection part 7400 can also perform environmental recognition processing such as identifying rainfall, fog, and road conditions based on the received information. The vehicle exterior information detection part 7400 can also calculate the distance to objects outside the vehicle based on the received information.

[0412] In addition, the vehicle exterior information detection part 7400 can also perform image recognition processing to identify people, vehicles, obstacles, signs, text on the road surface, etc. or detect the distance between them based on the received image data. The vehicle exterior information detection part 7400 can perform distortion aberration correction or position alignment processing on the received image data, and synthesize the image data captured by multiple different imaging parts 7410 to generate a bird's-eye view image or a panoramic image. The vehicle exterior information detection part 7400 can also use the image data captured by the imaging part 7410 including different imaging parts to perform viewpoint conversion processing.

[0413] The vehicle-mounted information detection part 7500 detects information inside the vehicle. The vehicle-mounted information detection part 7500 is connected to, for example, a driver state detection part 7510 that detects the state of the driver. The driver state detection part 7510 may include a camera that images the driver, a biosensor that detects the driver's biometric information, a microphone that collects sounds inside the vehicle, and the like. The biosensor is, for example, arranged in a seat surface, a steering wheel, and the like, and detects biometric information of an occupant sitting in a seat or a driver holding the steering wheel. The vehicle-mounted information detection part 7500 can calculate the driver's fatigue or concentration, or determine whether the driver is dozing off, based on the detection information input from the driver state detection part 7510. The vehicle-mounted information detection part 7500 can also perform noise elimination processing and the like on the sound signal obtained by collecting the sound.

[0414] The integrated control unit 7600 controls the overall operation within the vehicle control system 7000 according to various programs. The integrated control unit 7600 is connected to the input part 7800. The input part 7800 is implemented by a device capable of input operation by a passenger, such as a touch panel, a button, a microphone, a switch, a joystick, etc. Data obtained by voice recognition of a voice input via a microphone can be provided to the integrated control unit 7600. The input part 7800 can be, for example, a remote control device using infrared or other radio waves, or an external connection device that supports the operation of the vehicle control system 7000, such as a mobile phone, a personal digital assistant (PDA), etc. The input part 7800 can be, for example, a camera. In this case, the occupant can input information by gestures. Alternatively, data obtained by detecting the movement of a wearable device worn by the occupant can be input. In addition, the input part 7800 can include, for example, an input control circuit, etc., which generates an input signal based on the information input by the occupant, etc. using the above-mentioned input part 7800, and outputs the generated input signal to the integrated control unit 7600. The occupant or the like inputs various data or gives instructions for processing operations to the vehicle control system 7000 by operating the input portion 7800 .

[0415] The storage portion 7690 may include a read-only memory (ROM) storing various programs executed by the microcomputer and a random access memory (RAM) storing various parameters, operation results, sensor values, etc. In addition, the storage portion 7690 may be implemented by a magnetic storage device such as a hard disk drive (HDD), a semiconductor storage device, an optical storage device, a magneto-optical storage device, or the like.

[0416] The general communication I / F 7620 is a widely used communication I / F that serves as a medium for communication with various devices existing in the external environment 7750. The general communication I / F 7620 can implement a cellular communication protocol such as Global System for Mobile Communications (GSM (registered trademark)), Worldwide Interoperability for Microwave Access (WiMAX (registered trademark)), Long Term Evolution (LTE (registered trademark)), LTE Advanced (LTE-A), etc. or another wireless communication protocol such as wireless LAN (also known as Wireless Fidelity (Wi-Fi (registered trademark)), Bluetooth (registered trademark), etc. The general communication I / F 7620 can be connected to a device (e.g., an application server or a control server) existing on an external network (e.g., the Internet, a cloud network, or a company private network) via a base station or an access point, for example. In addition, the general communication I / F 7620 can be connected to a terminal existing near the vehicle (the terminal is, for example, a terminal of a driver, a pedestrian, or a store, or a machine type communication (MTC) terminal) using, for example, a point-to-point (P2P) technology.

[0417] The dedicated communication I / F 7630 is a communication I / F that supports a communication protocol developed for use in a vehicle. The dedicated communication I / F 7630 may implement a standard protocol, for example, such as Wireless Access in Vehicular Environments (WAVE) (which is a combination of the Institute of Electrical and Electronics Engineers (IEEE) 802.11p as a lower layer and IEEE 1609 as a higher layer), a dedicated short-range communication (DSRC), or a cellular communication protocol. The dedicated communication I / F 7630 typically performs V2X communication, a concept of which includes one or more of communication between vehicles and vehicles (vehicle-to-vehicle), communication between roads and vehicles (vehicle-to-infrastructure), communication between vehicles and homes (vehicle-to-home), and communication between pedestrians and vehicles (vehicle-to-pedestrian).

[0418] For example, the positioning section 7640 performs positioning by receiving a global navigation satellite system (GNSS) signal from a GNSS satellite (e.g., a GPS signal from a global positioning system (GPS) satellite), and generates position information including the latitude, longitude, and altitude of the vehicle. Incidentally, the positioning section 7640 can identify the current position by exchanging signals with a wireless access point, or can obtain position information from a terminal such as a mobile phone, a personal handyphone system (PHS), or a smart phone with a positioning function.

[0419] The beacon receiving section 7650 receives, for example, radio waves or electromagnetic waves transmitted from a radio station installed on a road or the like, thereby obtaining information on the current position, congestion, closed roads, necessary time, etc. Incidentally, the function of the beacon receiving section 7650 may be included in the above-mentioned dedicated communication I / F 7630.

[0420] The vehicle-mounted device I / F 7660 is a communication interface that mediates the connection between the microcomputer 7610 and various vehicle-mounted devices 7760 present in the vehicle. The vehicle-mounted device I / F 7660 can establish a wireless connection using a wireless communication protocol such as wireless LAN, Bluetooth (registered trademark), near field communication (NFC), or wireless universal serial bus (WUSB). In addition, the vehicle-mounted device I / F 7660 can establish a wired connection via a connection terminal (and a cable if necessary) not shown in the figure through a universal serial bus (USB), a high-definition multimedia interface (HDMI (registered trademark)), a mobile high-definition link (MHL), etc. The vehicle-mounted device 7760 may, for example, include at least one of a mobile device and a wearable device owned by an occupant and an information device carried into or attached to the vehicle. The vehicle-mounted device 7760 may also include a navigation device that searches for a path to an arbitrary destination. The vehicle-mounted device I / F 7660 exchanges control signals or data signals with these vehicle-mounted devices 7760.

[0421] The in-vehicle network I / F 7680 is an interface that serves as a communication medium between the microcomputer 7610 and the communication network 7010. The in-vehicle network I / F 7680 transmits and receives signals and the like in accordance with a predetermined protocol supported by the communication network 7010.

[0422] The microcomputer 7610 of the integrated control unit 7600 controls the vehicle control system 7000 according to various programs based on information obtained via at least one of the general communication I / F 7620, the dedicated communication I / F 7630, the positioning part 7640, the beacon receiving part 7650, the vehicle-mounted device I / F 7660, and the vehicle-mounted network I / F 7680. For example, the microcomputer 7610 can calculate a control target value for a driving force generating device, a steering mechanism, or a braking device based on the obtained information about the inside and outside of the vehicle, and output a control command to the drive system control unit 7100. For example, the microcomputer 7610 can perform cooperative control aimed at realizing functions of an advanced driver assistance system (ADAS), including collision avoidance or impact mitigation of a vehicle, follow-up driving based on a following distance, vehicle speed maintenance driving, warning of a vehicle collision, warning of a vehicle leaving a lane, and the like. In addition, the microcomputer 7610 can perform cooperative control intended for autonomous driving based on the information obtained about the vehicle's surroundings by controlling the drive force generating device, steering mechanism, braking device, etc., which enables the vehicle to drive autonomously without relying on the driver's operation, etc.

[0423] The microcomputer 7610 can generate three-dimensional distance information between the vehicle and objects such as surrounding structures, people, etc., and generate local map information including information about the surrounding environment of the current position of the vehicle based on information obtained via at least one of the general communication I / F 7620, the dedicated communication I / F 7630, the positioning part 7640, the beacon receiving part 7650, the vehicle-mounted device I / F 7660, and the vehicle-mounted network I / F 7680. In addition, the microcomputer 7610 can predict dangers such as collision of vehicles, approach of pedestrians, etc., entering a closed road, etc. based on the obtained information, and generate a warning signal. The warning signal can be, for example, a signal for generating a warning sound or lighting a warning lamp.

[0424] The sound / image output portion 7670 transmits an output signal of at least one of sound and image to an output device capable of visually or auditorily notifying information to the occupants of the vehicle or the outside of the vehicle. Fig.29In the example of , as output devices, an audio speaker 7710, a display portion 7720, and an instrument panel 7730 are illustrated. The display portion 7720 may, for example, include at least one of an on-board display and a head-up display. The display portion 7720 may have an augmented reality (AR) display function. The output device may be a device other than these devices, and may be another device such as headphones, a wearable device such as a glasses-type display worn by an occupant, a projector, a lamp, etc. In the case where the output device is a display device, the display device visually displays the results obtained by various processes performed by the microcomputer 7610 or information received from another control unit in various forms such as text, images, tables, charts, etc. In addition, in the case where the output device is an audio output device, the audio output device converts an audio signal composed of reproduced audio data or sound data, etc. into an analog signal, and outputs the analog signal auditorily.

[0425] By the way, in Fig.29 In the example shown, at least two control units connected to each other via the communication network 7010 may be integrated into one control unit. Alternatively, each individual control unit may include multiple control units. In addition, the vehicle control system 7000 may include another control unit not shown in the figure. In addition, some or all of the functions performed by one of the above control units may be assigned to another control unit. That is, as long as information is sent and received via the communication network 7010, a predetermined operation process may be performed by any control unit. Similarly, a sensor or device connected to one of the control units may be connected to another control unit, and multiple control units may send and receive detection information to each other via the communication network 7010.

[0426] In the above-mentioned vehicle control system 7000 , the imaging lens and the imaging device of the present disclosure may be applied to the imaging portion 7410 and any one of the imaging portions 7910 , 7912 , 7914 , 7916 , and 7918 .

[0427] [6.2 Second application example]

[0428] The technology according to the present disclosure can be applied to an endoscopic surgery system.

[0429] Fig.31 FIG. 5 is a diagram showing an example of a schematic configuration of an endoscopic surgery system 5000 to which the technology of the embodiment of the present invention can be applied. Fig.31, a surgeon (doctor) 5067 is shown performing surgery on a patient 5071 on a patient bed 5069 using an endoscopic surgery system 5000. As shown in the figure, the endoscopic surgery system 5000 includes an endoscope 5001, other surgical tools 5017, a support arm device 5027 on which the endoscope 5001 is supported, and a cart 5037 on which various devices for endoscopic surgery are installed.

[0430] In endoscopic surgery, instead of cutting the abdominal wall to perform laparotomy, multiple tubular aperture devices called trocars 5025a to 5025d are used to puncture the abdominal wall. Then, the lens barrel 5003 of the endoscope 5001 and other surgical tools 5017 are inserted into the body cavity of the patient 5071 through the trocars 5025a to 5025d. In the depicted example, as other surgical tools 5017, a pneumoperitoneum tube 5019, an energy device 5021 and forceps 5023 are inserted into the body cavity of the patient 5071. In addition, the energy device 5021 is a processing tool for cutting and peeling off tissues, sealing blood vessels, etc. by high-frequency current or ultrasonic vibration. However, the surgical tool 5017 depicted is only an example, and as the surgical tool 5017, various surgical tools commonly used in endoscopic surgery, such as forceps or retractors, can be used.

[0431] An image of a surgical site in a body cavity of a patient 5071 captured by the endoscope 5001 is displayed on a display device 5041. The surgeon 5067 performs treatment such as, for example, resection of a diseased area using an energy device 5021 or forceps 5023 while observing in real time the image of the surgical area displayed on the display device 5041. It should be noted that, although not shown, the pneumoperitoneum tube 5019, the energy device 5021, and the forceps 5023 are supported by the surgeon 5067, an assistant, etc. during surgery.

[0432] (Support arm equipment)

[0433] The support arm device 5027 includes an arm unit 5031 extending from a base unit 5029. In the example shown, the arm unit 5031 includes joint portions 5033a, 5033b, and 5033c and connecting rods 5035a and 5035b, and is driven under the control of the arm control device 5045. The endoscope 5001 is supported by the arm unit 5031 so that the position and posture of the endoscope 5001 are controlled. Therefore, stable fixation in position of the endoscope 5001 can be achieved.

[0434] (Endoscope)

[0435] The endoscope 5001 includes a barrel 5003 having a predetermined length from its distal end to be inserted into a body cavity of a patient 5071 and a camera head 5005 connected to the proximal end of the barrel 5003. In the example shown, the endoscope 5001 is described as a rigid endoscope having a hard barrel 5003. However, the endoscope 5001 may be additionally configured as a flexible endoscope having a flexible barrel 5003.

[0436] The lens barrel 5003 has an opening at its distal end, and the objective lens is assembled in the opening. The light source device 5043 is connected to the endoscope 5001, so that the light generated by the light source device 5043 is introduced into the distal end of the lens barrel through the light guide extending inside the lens barrel 5003, and irradiated toward the observation target in the body cavity of the patient 5071 through the objective lens. Note that the endoscope 5001 can be an endoscope for front observation, an endoscope for oblique observation, or an endoscope for side observation.

[0437] An optical system and an image pickup element are provided inside the camera head 5005 so that reflected light (observation light) from an observation target is converged on the image pickup element through the optical system. The observation light is photoelectrically converted by the imaging element to generate an electric signal corresponding to the observation light, that is, an image signal corresponding to the observation image. The image signal is sent to the CCU 5039 as RAW data. Note that the camera head 5005 has a function incorporated therein for appropriately driving the optical system of the camera head 5005 to adjust the magnification and focal length.

[0438] Note that in order to establish compatibility with, for example, stereoscopic vision (three-dimensional (3D) display), a plurality of image pickup elements may be provided on the camera head 5005. In this case, a plurality of relay optical systems are provided inside the lens barrel 5003 in order to guide observation light to each of the plurality of image pickup elements.

[0439] (Various equipment in the cart)

[0440] The CCU 5039 includes a central processing unit (CPU), a graphics processing unit (GPU), etc., and integrally controls the operations of the endoscope 5001 and the display device 5041. Specifically, the CCU 5039 performs various image processing for displaying an image based on the image signal, for example, development processing (demosaic processing), on the image signal received from the camera head 5005. The CCU 5039 provides the image signal on which the image processing has been performed to the display device 5041. In addition, the CCU 5039 transmits a control signal to the camera head 5005 to control the driving of the camera head 5005. The control signal may include information related to image pickup conditions such as magnification or focal length.

[0441] The display device 5041 displays an image based on an image signal on which image processing has been performed by the CCU 5039 under the control of the CCU 5039. If the endoscope 5001 is prepared for high-resolution imaging, such as 4K (horizontal pixel number 3840×vertical pixel number 2160), 8K (horizontal pixel number 7680×vertical pixel number 4320), etc., and / or for 3D display, a display device of a corresponding display of the high-resolution and / or 3D display can be used as the display device 5041. In the case where the device is prepared for imaging of a high resolution such as 4K or 8K, if the display device used as the display device 5041 has a size equal to or not less than 55 inches, a more immersive experience can be obtained. In addition, a plurality of display devices 5041 having different resolutions and / or different sizes can be provided according to the purpose.

[0442] The light source device 5043 includes a light source, such as a light emitting diode (LED), and provides the endoscope 5001 with illumination light for imaging the surgical area.

[0443] The arm control device 5045 includes a processor such as a CPU, and operates according to a predetermined program to control the driving of the arm unit 5031 supporting the arm device 5027 according to a predetermined control method.

[0444] The input device 5047 is an input interface of the endoscopic surgery system 5000. The user can input various information or instructions to the endoscopic surgery system 5000 via the input device 5047. For example, the user will input various information related to the surgery, such as the patient's physical information, information related to the surgical process of the surgery, etc. through the input device 5047. In addition, the user will input, for example, instructions to drive the arm unit 5031, instructions to change the image pickup conditions (type of irradiation light, magnification, focal length, etc.) performed by the endoscope 5001, instructions to drive the energy device 5021, etc. through the input device 5047.

[0445] The type of input device 5047 is not limited, and may be any of various known input devices. As input device 5047, for example, a mouse, a keyboard, a touch panel, a switch, a foot switch 5057 and / or a lever, etc. may be applied. In the case where a touch panel is used as input device 5047, it may be provided on the display surface of display device 5041.

[0446] In addition, the input device 5047 is a device installed on the user, such as a glasses-type wearable device or a head-mounted display (HMD), and various inputs are performed in response to the posture or sight of the user detected by any of the devices mentioned. In addition, the input device 5047 includes a camera that can detect the user's movement, and various inputs are performed in response to the posture or sight of the user detected from the video captured by the camera. In addition, the input device 5047 includes a microphone that can collect the user's voice, and various inputs are performed by the voice collected by the microphone. By configuring the input device 5047 in this way, various information can be input in a non-contact manner, and in particular, users (such as surgeons 5067) belonging to the clean area can operate the equipment belonging to the non-clean area in a non-contact manner. In addition, since the user can operate the equipment without releasing the surgical tools owned by the hand, the convenience of the user is improved.

[0447] The treatment tool control device 5049 controls the driving of the energy device 5021 to perform cauterization or incision of tissues, sealing of blood vessels, etc. The pneumoperitoneum device 5051 supplies gas to the body cavity of the patient 5071 through the pneumoperitoneum tube 5019 to expand the body cavity, thereby ensuring the field of view of the endoscope 5001 and ensuring the working space of the surgeon. The recorder 5053 is a device capable of recording various information related to the operation. The printer 5055 is a device capable of printing various information related to the operation in various forms such as text, images, or graphics.

[0448] Hereinafter, the characteristic configuration of the endoscopic surgery system 5000 will be described in particular detail.

[0449] (Support arm equipment)

[0450] The supporting arm device 5027 includes a base unit 5029 serving as a base and an arm unit 5031 extending from the base unit 5029. In the example shown, the arm unit 5031 includes a plurality of joint portions 5033a, 5033b, and 5033c and a plurality of links 5035a and 5035b connected to each other through the joint portion 5033b. Fig.31 In order to simplify the description, the structure of the arm unit 5031 is described in a simplified form. In fact, the shape, quantity and configuration of the joint parts 5033a-5033c and the connecting rods 5035a and 5035b, as well as the direction of the rotation axis of the joint parts 5033a-5033c, etc. can be appropriately set so that the arm unit 5031 has a desired degree of freedom. For example, the arm unit 5031 can preferably be constructed so that it has a degree of freedom equal to or not less than 6 degrees of freedom. This makes it possible to freely move the endoscope 5001 within the movable range of the arm unit 5031. Therefore, the lens barrel 5003 of the endoscope 5001 can be inserted into the body cavity of the patient 5071 from the desired direction.

[0451] Actuators are provided on the joint parts 5033a to 5033c, respectively, and the joint parts 5033a to 5033c are configured to be rotatable around a specified rotation axis by driving each actuator. The drive of the actuator is controlled by the arm control device 5045 to control the rotation angle of each of the joint parts 5033a to 5033c, thereby controlling the drive of the arm unit 5031. Therefore, the control of the position and posture of the endoscope 5001 can be achieved. Therefore, the arm control device 5045 can control the drive of the arm unit 5031 by various known control methods, such as force control or position control.

[0452] For example, when the surgeon 5067 appropriately performs an operation input through the input device 5047 (including the foot switch 5057), the arm control device 5045 appropriately controls the drive of the arm unit 5031 in response to the operation input, and controls the position and posture of the endoscope 5001. After the endoscope 5001 at the distal end of the arm unit 5031 is moved from an arbitrary position to a different arbitrary position through the control just described, the endoscope 5001 can be fixedly supported at the position after the movement. It should be noted that the arm unit 5031 can be operated in a master-slave manner. In this case, the user can remotely control the arm unit 5031 through the input device 5047 placed at a location away from the operating room.

[0453] In addition, in the case of applying force control, the arm control device 5045 can perform power-assisted control to drive the actuators of the joint parts 5033a to 5033c, so that the arm unit 5031 can receive the external force of the user and move smoothly following the external force. This makes it possible to move the arm unit 5031 with a relatively weak force when the user directly touches and moves the arm unit 5031. Therefore, the user can move the endoscope 5001 more intuitively with a simpler and easier operation, which can improve the convenience of the user.

[0454] Here, usually in endoscopic surgery, endoscope 5001 is supported by a doctor called an endoscopist. In contrast, when support arm device 5027 is used, the position of endoscope 5001 can be fixed more surely without using hands, so that an image of the surgical field can be stably obtained and surgery can be performed smoothly.

[0455] It should be noted that the arm control device 5045 may not necessarily be provided on the cart 5037. In addition, the arm control device 5045 may not necessarily be a single device. For example, the arm control device 5045 may be provided in each of the joint portions 5033a to 5033c of the arm unit 5031 supporting the arm device 5027 so that a plurality of arm control devices 5045 cooperate with each other to achieve drive control of the arm unit 5031.

[0456] (Light source equipment)

[0457] The light source device 5043 provides the irradiation light when the surgical area is imaged to the endoscope 5001. The light source device 5043 includes a white light source, which includes, for example, an LED, a laser light source, or a combination thereof. In this case, in the case where the white light source includes a combination of red, green, and blue (RGB) laser light sources, since the output intensity and output timing can be controlled with high precision for each color (each wavelength), the adjustment of the white balance of the picked-up image can be performed by the light source device 5043. In addition, in this case, if the laser beams from the respective RGB laser sources are irradiated on the observation target in time division, and the drive of the image pickup element of the camera head 5005 is controlled synchronously with the irradiation timing, images corresponding to the R, G, and B colors can be picked up in time division. According to the method just described, a color image can be obtained even if a color filter is not provided for the image pickup element.

[0458] In addition, the drive of the light source device 5043 can also be controlled so that the intensity of the output light changes at every specified time. By controlling the drive of the image pickup element of the camera head 5005 in synchronization with the timing of the change in light intensity to acquire images in a time-division manner and synthesize the images, a high dynamic range image without underexposed shadows and overexposed highlights can be created.

[0459] In addition, the light source device 5043 may also be configured to provide light of a prescribed wavelength band for special light observation. In special light observation, for example, by utilizing the wavelength dependence of light absorption in biological tissue, light having a narrower wavelength band than the irradiated light during normal observation (i.e., white light) is irradiated to perform narrow-band light observation (narrow-band imaging) for imaging prescribed tissues such as blood vessels in the superficial part of the mucosa with high contrast. Alternatively, in special light observation, fluorescence observation for obtaining an image from fluorescence generated by irradiation of excitation light may be performed. In fluorescence observation, fluorescence from body tissue may be observed by irradiating excitation light onto body tissue (autofluorescence observation), or a fluorescence image may be obtained by locally injecting a reagent such as indocyanine green (ICG) into the body tissue and irradiating excitation light corresponding to the fluorescence wavelength of the reagent onto the body tissue. The light source device 5043 may be configured to provide narrow-band light and / or excitation light suitable for special light observation as described above.

[0460] (Camera head and CCU)

[0461] Reference Fig.32 The functions of the camera head 5005 and CCU 5039 of the endoscope 5001 are described in more detail. Fig.32 It is a depiction Fig.31 A block diagram of an example of a functional configuration of a camera head 5005 and a CCU 5039 is depicted.

[0462] Reference Fig.32 , the camera head 5005 has as its functions a lens unit 5007, an image pickup unit 5009, a drive unit 5011, a communication unit 5013, and a camera head control unit 5015. In addition, the CCU 5039 has as its functions a communication unit 5059, an image processing unit 5061, and a control unit 5063. The camera head 5005 and the CCU 5039 are connected via a transmission cable 5065 so as to be able to communicate with each other bidirectionally.

[0463] First, the functional configuration of the camera head 5005 is described. The lens unit 5007 is an optical system provided at the connection position of the camera head 5005 and the lens barrel 5003. The observation light introduced from the far end of the lens barrel 5003 is introduced into the camera head 5005 and enters the lens unit 5007. The lens unit 5007 includes a combination of a plurality of lenses including a zoom lens and a focus lens. The lens unit 5007 has an optical characteristic adjusted so that the observation light is converged on the light receiving surface of the image pickup element of the image pickup unit 5009. In addition, the zoom lens and the focus lens are configured so that their positions on their optical axes are movable for adjusting the magnification and focus of the picked-up image.

[0464] The image pickup unit 5009 includes an image pickup element and is arranged at a later stage of the lens unit 5007. The observation light passing through the lens unit 5007 is condensed on a light receiving surface of the image pickup element, and an image signal corresponding to the observation image is generated by photoelectric conversion of the image pickup element. The image signal generated by the image pickup unit 5009 is provided to the communication unit 5013.

[0465] As the image pickup element included in the image pickup unit 5009, for example, a complementary metal oxide semiconductor (CMOS) type image sensor is used, which has a Bayer array and can pick up a color image. It should be noted that as the image pickup element, for example, an image pickup element prepared for imaging at a high resolution equal to or not less than 4K can be used. If an image of the surgical area is obtained at a high resolution, the doctor 5067 can understand the state of the surgical area with enhanced details and can perform surgery more smoothly.

[0466] In addition, the image pickup element included in the image pickup unit 5009 includes a pair of image pickup elements for acquiring right-eye and left-eye image signals compatible with 3D display. In the case of applying 3D display, the doctor 5067 can more accurately grasp the depth of the living tissue in the surgical area. It should be noted that if the image pickup unit 5009 is configured as a multi-plate image pickup unit, a plurality of systems of lens units 5007 are provided corresponding to the respective image pickup elements of the image pickup unit 5009.

[0467] The image pickup unit 5009 may not necessarily be provided on the camera head 5005. For example, the image pickup unit 5009 may be provided in the interior of the lens barrel 5003 just behind the objective lens.

[0468] The driving unit 5011 includes an actuator and moves the zoom lens and the focus lens of the lens unit 5007 by a predetermined distance along the optical axis under the control of the camera head control unit 5015. Therefore, the magnification and focus of the image picked up by the image pickup unit 5009 can be appropriately adjusted.

[0469] The communication unit 5013 includes a communication device for sending and receiving various information to and from the CCU 5039. The communication unit 5013 sends the image signal acquired from the camera unit 5009 as RAW data to the CCU 5039 via the transmission cable 5065. Therefore, in order to display the picked-up image of the operating area with low latency, it is preferable to transmit the image signal through optical communication. This is because, during the operation, the surgeon 5067 performs the operation while observing the state of the diseased area through the picked-up image. In order to perform the operation with higher safety and certainty, it is necessary to display the moving image of the operating area as real time as possible. In the case of applying optical communication, a photoelectric conversion module for converting an electrical signal into an optical signal is provided in the communication unit 5013. After the image signal is converted into an optical signal by the photoelectric conversion module, it is transmitted to the CCU 5039 through the transmission cable 5065.

[0470] In addition, the communication unit 5013 receives a control signal for controlling the drive of the camera head 5005 from the CCU 5039. The control signal includes information related to image pickup conditions, such as information specifying the frame rate of the picked-up image, information specifying the exposure value when the image is picked up, and / or information specifying the magnification and focus of the picked-up image. The communication unit 5013 provides the received control signal to the camera head control unit 5015. It should be noted that the control signal from the CCU 5039 can also be transmitted through optical communication. In this case, a photoelectric conversion module for converting an optical signal into an electrical signal is provided in the communication unit 5013. After the control signal is converted into an electrical signal by the photoelectric conversion module, it is provided to the camera head control unit 5015.

[0471] It should be noted that the control unit 5063 of the CCU 5039 automatically sets image pickup conditions such as frame rate, exposure value, magnification or focus based on the acquired image signal. In other words, an automatic exposure (AE) function, an automatic focus (AF) function, and an automatic white balance (AWB) function are incorporated in the endoscope 5001.

[0472] The camera head control unit 5015 controls the driving of the camera head 5005 based on the control signal received from the CCU 5039 through the communication unit 5013. For example, the camera head control unit 5015 controls the driving of the image pickup element of the image pickup unit 5009 based on the information specifying the frame rate of the picked-up image and / or the information specifying the exposure value at the time of image pickup. In addition, for example, the camera head control unit 5015 controls the driving unit 5011 so as to appropriately move the zoom lens and the focus lens of the lens unit 5007 based on the information specifying the magnification and focus of the picked-up image. The camera head control unit 5015 may also include a function for storing information for identifying the lens barrel 5003 and / or the camera head 5005.

[0473] It should be noted that by arranging components such as the lens unit 5007 and the image pickup unit 5009 in a sealed structure with high airtightness and waterproofness, the camera head 5005 can be provided with resistance to high-pressure sterilization processing.

[0474] Now, the functional configuration of the CCU 5039 is described. The communication unit 5059 includes a communication device for sending and receiving various information to and from the camera head 5005. The communication unit 5059 receives an image signal transmitted thereto from the camera head 5005 through a transmission cable 5065. Therefore, preferably, the image signal can be transmitted through optical communication as described above. In this case, in order to be compatible with optical communication, the communication unit 5059 includes a photoelectric conversion module for converting an optical signal into an electrical signal. The communication unit 5059 provides the image signal after conversion into the electrical signal to the image processing unit 5061.

[0475] Furthermore, the communication unit 5059 transmits a control signal for controlling the driving of the camera head 5005 to the camera head 5005. The control signal may also be transmitted by optical communication.

[0476] The image processing unit 5061 performs various image processing on the image signal in the form of RAW data sent thereto from the camera head 5005. The image processing includes various known signal processing, such as development processing, image quality improvement processing (bandwidth enhancement processing, super-resolution processing, noise reduction (NR) processing, and / or image stabilization processing), and / or magnification processing (electronic zoom processing). In addition, the image processing unit 5061 performs detection processing on the image signal in order to perform AE, AF, and AWB.

[0477] The image processing unit 5061 includes a processor such as a CPU or a GPU, and when the processor operates according to a predetermined program, the above-mentioned image processing and detection processing can be performed. Note that in the case where the image processing unit 5061 includes a plurality of GPUs, the image processing unit 5061 appropriately divides the information related to the image signal so that the image processing is performed in parallel by the plurality of GPUs.

[0478] The control unit 5063 performs various controls related to the imaging of the surgical site and the display of the imaging image by the endoscope 5001. For example, the control unit 5063 generates a control signal for controlling the driving of the camera head 5005. Therefore, if the user inputs the image pickup condition, the control unit 5063 generates a control signal based on the user's input. Alternatively, in the case where the endoscope 5001 has an AE function, an AF function, and an AWB function built in, the control unit 5063 appropriately calculates the optimal exposure value, focal length, and white balance based on the detection processing result of the image processing unit 5061, and generates a control signal.

[0479] In addition, the control unit 5063 controls the display device 5041 to display the image of the surgical area based on the image signal on which the image processing unit 5061 has performed image processing. Thus, the control unit 5063 uses various image recognition technologies to recognize various objects in the surgical area image. For example, the control unit 5063 can recognize surgical tools such as forceps, specific living body areas, bleeding, fog when the energy device 5021 is used, etc. by detecting the shape, color, etc. of the edge of the object included in the surgical area image. When the control unit 5063 controls the display part 5041 to display the surgical site image, it causes various surgical auxiliary information to be displayed overlapping with the surgical site image according to the recognition result. In the case where the surgical auxiliary information is displayed overlappingly and prompted to the surgeon 5067, the surgeon 5067 can perform the operation more safely and reliably.

[0480] The transmission cable 5065 connecting the camera head 5005 and the CCU 5039 to each other is an electric signal cable ready for communication of electric signals, an optical fiber ready for optical communication, or a composite cable ready for both electric and optical communication.

[0481] Here, although in the example shown, communication is performed by wired communication using the transmission cable 5065, communication between the camera head 5005 and the CCU 5039 may be performed by wireless communication in other ways. In the case where communication between the camera head 5005 and the CCU 5039 is performed by wireless communication, it is not necessary to lay the transmission cable 5065 in the operating room. Therefore, it is possible to eliminate the situation where the movement of medical staff in the operating room is disturbed by the transmission cable 5065.

[0482] In the above, an example of an endoscopic surgery system 5000 to which the technology according to the embodiment of the present invention can be applied is described. Although the endoscopic surgery system 5000 is used as an example for description, the system to which the technology according to the embodiment of the present invention can be applied is not limited to this example. For example, the technology according to the embodiment of the present disclosure can be applied to a flexible endoscope system or a microsurgery system for inspection.

[0483] The technology according to the present disclosure can be preferably applied to the camera head 5005 in the above-mentioned components. In particular, the imaging lens according to the present disclosure can be preferably applied to the lens unit 5007 of the camera head 5005.

[0484] <7. Other embodiments>

[0485] The technology according to the present disclosure is not limited to the description of the above-mentioned embodiments and examples, and may be modified and operated in various ways.

[0486] For example, the shapes and numerical values ​​of the respective parts illustrated in each of the aforementioned numerical examples are merely examples of implementation of the present technology, and the technical scope of the present technology should not be construed as being limited by these examples.

[0487] In addition, although a description has been given of a configuration that basically includes six or seven lenses in the above-mentioned embodiments and examples, a configuration that also includes a lens that does not have substantial refractive power may be adopted. In addition, the imaging lens of the present disclosure may have a configuration of five or fewer lenses or eight or more lenses.

[0488] In addition, for example, the present technology may also have the following configurations.

[0489] According to the present technology having the following configuration, the front group lens system and the rear group lens system are arranged in order from the object side to the image plane side to optimize the configuration of each lens system. Thus, it is possible to provide a high-performance imaging lens having a small size for an optical system, which is suitable for an imaging element of a large element size and has various aberrations well corrected, and an imaging device. [1]

[0491] An imaging lens, comprising, from the object side to the image side where the imaging element is arranged, the following:

[0492] A front lens system having positive refractive power; and

[0493] A rear lens system having a lens surface which is concave toward the image plane in the vicinity of the optical axis and convex toward the image plane in the peripheral portion on the side closest to the image plane,

[0494] The following conditional expressions are met:

[0495] 1.0<Gun2R2 (sag6-sag10) / (TTL / 2Y)<2.8......(1)

[0496] 5.0(%)<OD MAX <20.0(%)......(2)

[0497] in,

[0498] Gun2R2 (sag6-sag10) It represents the distance between two points parallel to the optical axis, on the lens surface closest to the image plane of the rear lens system, between the point where the principal ray of 60% of the image height intersects with the point where the principal ray of 100% of the image height intersects, in units of "mm",

[0499] TTL represents the distance from the vertex of the lens surface on the side closest to the object of the front lens system to the image plane on the optical axis.

[0500] 2Y represents the diagonal length of the imaging element, and

[0501] OD MAX It represents the maximum value of the distortion aberration within the imaging area generated by the imaging lens. [2]

[0503] The imaging lens according to [1], wherein:

[0504] The front lens system includes a plurality of lenses, and

[0505] The rear lens system includes a single lens. [3]

[0507] The imaging lens according to [1] or [2], wherein:

[0508] The front lens system includes, in order from the object side to the image side,

[0509] A first lens having positive refractive power near the optical axis,

[0510] A second lens having positive or negative refractive power near the optical axis,

[0511] The third lens has negative refractive power near the optical axis,

[0512] a fourth lens having negative refractive power near the optical axis, and

[0513] a fifth lens having positive or negative refractive power near the optical axis, and

[0514] The rear lens system includes a sixth lens having positive or negative refractive power near the optical axis. [4]

[0516] The imaging lens according to any one of [1] to [3], wherein the following conditional expression is satisfied:

[0517] 1.7<f / Gun1R1<2.8......(3)

[0518] in,

[0519] f represents the focal length of the entire lens system, and

[0520] Gun1R1 represents the radius of curvature of the lens surface of the front lens system on the side closest to the object. [5]

[0522] The imaging lens according to any one of [1] to [4], wherein the following conditional expression is satisfied:

[0523] 2.2<f / Gun2R2<3.8......(4)

[0524] in,

[0525] f represents the focal length of the entire lens system, and

[0526] Gun2R2 represents the radius of curvature of the lens surface of the rear lens system that is closest to the image plane. [6]

[0528] The imaging lens according to any one of [1] to [5], wherein:

[0529] The front lens system includes a first lens, a second lens, a third lens and a fourth lens in order from the object side to the image side, and

[0530] The following conditions are met:

[0531] 17.3<νd(L4)<61.7......(5)

[0532] in,

[0533] νd(L4) represents the Abbe number of the fourth lens with respect to the d-line. [7]

[0535] The imaging lens according to any one of [1] to [6], wherein:

[0536] The front lens system includes a first lens, a second lens, a third lens, a fourth lens and a fifth lens in order from the object side to the image side, and

[0537] The following conditional expressions are met:

[0538] 20.2<νd(L5)<61.3......(6)

[0539] in,

[0540] νd(L5) represents the Abbe number of the fifth lens with respect to the d-line. [8]

[0542] The imaging lens according to any one of [1] to [7], wherein:

[0543] The front lens system includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens in order from the object side to the image side, and

[0544] The following conditional expressions are met:

[0545] 23.2<νd(L6)<61.3......(7)

[0546] in,

[0547] νd(L6) represents the Abbe number of the sixth lens with respect to the d-line. [9]

[0549] The imaging lens according to any one of [1] to [8], wherein:

[0550] The front lens system includes a first lens, a second lens and a third lens in order from the object side to the image side, and

[0551] The aperture stop is arranged between the lens surface of the first lens on the object side and the lens surface of the first lens on the image plane side, or between the lens surface of the first lens on the image plane side and the lens surface of the second lens on the image plane side, or between the lens surface of the second lens on the image plane side and the lens surface of the third lens on the image plane side.

[10]

[0553] The imaging lens according to any one of [1], [2], or [4] to [9], wherein:

[0554] The front lens system includes, in order from the object side to the image side,

[0555] A first lens having positive refractive power near the optical axis,

[0556] A second lens having positive refractive power near the optical axis,

[0557] The third lens has negative refractive power near the optical axis,

[0558] The fourth lens has positive or negative refractive power near the optical axis,

[0559] a fifth lens having negative refractive power near the optical axis, and

[0560] a sixth lens having positive or negative refractive power near the optical axis, and

[0561] The rear lens system includes a seventh lens having positive or negative refractive power near the optical axis.

[11]

[0563] An imaging device, comprising:

[0564] Imaging lens;

[0565] an imaging element that outputs an imaging signal corresponding to an optical image formed by the imaging lens; and

[0566] an arithmetic unit that corrects distortion aberration of an image captured by the imaging element,

[0567] The imaging lens includes, from the object side to the image plane side where the imaging element is arranged, the following:

[0568] A front lens system having positive refractive power; and

[0569] a rear lens system having, on the side closest to the image plane, a lens surface which is concave toward the image plane in the vicinity of the optical axis and convex toward the image plane in the peripheral portion, and

[0570] The imaging lens satisfies the following conditional expression:

[0571] 1.0<Gun2R2 (sag6-sag10) / (TTL / 2Y)<2.8......(1)

[0572] 5.0(%)<OD MAX <20.0(%)......(2)

[0573] in,

[0574] Gun2R2 (sag6-sag10) It represents the distance between two points parallel to the optical axis, on the lens surface closest to the image plane of the rear lens system, between the point where the principal ray of 60% of the image height intersects with the point where the principal ray of 100% of the image height intersects, in units of "mm",

[0575] TTL represents the distance from the vertex of the lens surface on the side closest to the object of the front lens system to the image plane on the optical axis.

[0576] 2Y represents the diagonal length of the imaging element, and

[0577] OD MAX It represents the maximum value of the distortion aberration within the imaging area generated by the imaging lens.

[12]

[0579] The imaging lens according to any one of [1] to

[10] further includes a lens having substantially no refractive power.

[13]

[0581] The imaging device according to

[11] , wherein the imaging lens further includes a lens having substantially no refractive power.

[0582] This application claims the benefit of Japanese Priority Patent Application JP 2019-68037 filed in the Japan Patent Office on Mar. 29, 2019, the entire contents of which are hereby incorporated by reference.

[0583] It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and alterations may occur depending on design requirements and other factors insofar as they are within the scope of the appended claims or the equivalents thereof.

Claims

1. An imaging lens, comprising, from the object side to the image side where the imaging element is arranged, the following: A front lens system with positive refractive power; as well as A rear lens system having a lens surface which is concave toward the image plane in the vicinity of the optical axis and convex toward the image plane in the peripheral portion on the side closest to the image plane, The following conditional expressions are met: 1.0<Gun2R2 (sag6-sag10) / (TTL / 2Y)<2.8......(1) 5.0(%)<OF MAX <20.0(%)......(2) in, Gun2R2 (sag6-sag10) It represents the distance between two points parallel to the optical axis, on the lens surface closest to the image plane of the rear lens system, between the point where the principal ray of 60% of the image height intersects with the point where the principal ray of 100% of the image height intersects, in units of "mm", TTL represents the distance from the vertex of the lens surface on the side closest to the object of the front lens system to the image plane on the optical axis. 2Y represents the diagonal length of the imaging element, and OD MAX represents the maximum value of the distortion aberration in the imaging area generated by the imaging lens, Among them, the following conditional expressions are satisfied: 1.9<f / Gun1R1<2.6......(3)', 2.4<f / Gun2R2<3.5......(4)' where f is the focal length of the entire lens system, and Gun1R1 represents the radius of curvature of the lens surface of the front lens system on the side closest to the object, Gun2R2 represents the radius of curvature of the lens surface of the rear lens system closest to the image plane. The front lens system includes, from the object side to the image side, A first lens having positive refractive power near the optical axis, A second lens having positive refractive power near the optical axis, The third lens has negative refractive power near the optical axis, The fourth lens element has positive or negative refractive power near the optical axis. a fifth lens having negative refractive power near the optical axis, and a sixth lens having positive or negative refractive power near the optical axis, and The rear lens system includes a seventh lens having positive or negative refractive power near the optical axis.

2. The imaging lens according to claim 1, wherein: The front lens system includes a plurality of lenses, and The rear lens system includes a single lens.

3. The imaging lens according to claim 1, wherein: The front lens system includes a first lens, a second lens, a third lens and a fourth lens in order from the object side to the image side, and The following conditions are met: 17.3<νd(L4)<61.7......(5) in, νd(L4) represents the Abbe number of the fourth lens with respect to the d-line.

4. The imaging lens according to claim 1, wherein: The front lens system includes a first lens, a second lens, a third lens, a fourth lens and a fifth lens in order from the object side to the image side, and The following conditional expressions are met: 20.2<νd(L5)<61.3......(6) in, νd(L5) represents the Abbe number of the fifth lens with respect to the d-line.

5. The imaging lens according to claim 1, wherein: The front lens system includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens in order from the object side to the image side, and The following conditional expressions are met: 23.2<νd(L6)<61.3......(7) in, νd(L6) represents the Abbe number of the sixth lens with respect to the d-line.

6. The imaging lens according to claim 1, wherein: The front lens system includes a first lens, a second lens and a third lens in order from the object side to the image side, and The aperture stop is arranged between the lens surface of the first lens on the object side and the lens surface of the first lens on the image plane side, or between the lens surface of the first lens on the image plane side and the lens surface of the second lens on the image plane side, or between the lens surface of the second lens on the image plane side and the lens surface of the third lens on the image plane side.

7. An imaging device comprising: Imaging lens; an imaging element that outputs an imaging signal corresponding to an optical image formed by the imaging lens; as well as an arithmetic unit that corrects distortion aberration of an image captured by the imaging element, The imaging lens includes, from the object side to the image plane side where the imaging element is arranged, the following: A front lens system having positive refractive power; and a rear lens system having, on the side closest to the image plane, a lens surface which is concave toward the image plane in the vicinity of the optical axis and convex toward the image plane in the peripheral portion, and The imaging lens satisfies the following conditional expression: 1.0<Gun2R2 (sag6-sag10) / (TTL / 2Y)<2.8......(1) 5.0(%)<OF MAX <20.0(%)......(2) in, Gun2R2 (sag6-sag10) It represents the distance between two points parallel to the optical axis, on the lens surface closest to the image plane of the rear lens system, between the point where the principal ray of 60% of the image height intersects with the point where the principal ray of 100% of the image height intersects, in units of "mm", TTL represents the distance from the vertex of the lens surface on the side closest to the object of the front lens system to the image plane on the optical axis. 2Y represents the diagonal length of the imaging element, and OD MAX represents the maximum value of the distortion aberration in the imaging area generated by the imaging lens, Among them, the following conditional expressions are satisfied: 1.9<f / Gun1R1<2.6......(3)', 2.4<f / Gun2R2<3.5......(4)' where f is the focal length of the entire lens system, and Gun1R1 represents the radius of curvature of the lens surface of the front lens system on the side closest to the object, Gun2R2 represents the radius of curvature of the lens surface of the rear lens system closest to the image plane. The front lens system includes, from the object side to the image side, A first lens having positive refractive power near the optical axis, A second lens having positive refractive power near the optical axis, The third lens has negative refractive power near the optical axis, The fourth lens element has positive or negative refractive power near the optical axis. a fifth lens having negative refractive power near the optical axis, and a sixth lens having positive or negative refractive power near the optical axis, and The rear lens system includes a seventh lens having positive or negative refractive power near the optical axis.

Images