Imaging lens and imaging device

Abstract

To provide a compact image capturing lens which has a wide view angle and a large aperture diameter and yet offers good optical performance.SOLUTION: An image capturing lens disclosed herein comprises a first lens group having positive refractive power, a second lens group having positive refractive power, and a third lens having negative refractive power, arranged in order from the object side to the image plane side, the first lens group having a first aspherical lens with negative refractive power located on the most object side. While focusing, the second lens group moves along an optical axis. The image capturing lens satisfies the following conditional expression: -2.5<f1 / f<-1.0 ...(1), where f1 represents a focal length of the first aspherical lens located on the most object side in the first lens group, and f represents a focal length of the entire system.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an imaging lens and an imaging device. [Background technology]

[0002] In recent years, imaging devices using solid-state imaging elements, such as digital still cameras, have become widely used. With the widespread use of digital still cameras, there is a demand for even higher image quality. In particular, digital still cameras with a high pixel count require imaging lenses with excellent imaging performance compatible with solid-state imaging elements with a high pixel count. Recently, there has also been a growing demand for compactness, a wide angle of view, and a large aperture to meet video shooting needs. Imaging lenses that satisfy all of these requirements are needed. Furthermore, miniaturization requires not only reductions in overall optical length and front lens diameter in the shooting state, but also in the state in which the lens group is housed within the camera body. Meanwhile, there is a demand for a wide-angle, large-aperture lens to be compatible with the above various requirements. There is a particular demand for a wide-angle, large-aperture lens. There are many types of imaging lenses used in digital still cameras, and one type of lens suited to wide-angle, large-aperture lenses is the retrofocus type (see Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-303791 [Patent Document 2] International Publication No. 2011 / 027690 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, various imaging lenses with large apertures on the wide-angle side have been proposed, but it is difficult to achieve both compactness and size reduction at the same time.

[0005] It is desirable to provide an imaging lens that is compact, has a wide angle, and has a large aperture, yet is capable of achieving good optical performance, and an imaging device that includes such an imaging lens. [Means for solving the problem]

[0006] An imaging lens according to an embodiment of the present disclosure includes, in order from an object side to an image plane side, a first lens group having positive refractive power, a second lens group having positive refractive power, and a third lens group having negative refractive power, the first lens group having a first aspherical lens having negative refractive power closest to the object side, the second lens group moving on an optical axis during focusing, The second lens group is composed of one biconvex positive lens element, and the lens surfaces before and after the positive lens element in the second lens group are configured so that their concave surfaces face the positive lens element, and the second lens group further has an aperture diaphragm. The following conditional expression is satisfied: -2.5 <f1 / f<-1.0 ……(1) 0.6 <LST / LT<0.9 ……(3)’ however, f1: focal length of the first aspherical lens located closest to the object in the first lens group f: focal length of the entire system LST: Distance from aperture stop to image plane LT: Optical total length Let's say.

[0007] An imaging device according to an embodiment of the present disclosure includes an imaging lens and an imaging element that outputs an imaging signal corresponding to an optical image formed by the imaging lens, and the imaging lens is configured by the imaging lens according to the embodiment of the present disclosure.

[0008] In an imaging lens or an imaging device according to an embodiment of the present disclosure, the configuration of each lens group is optimized so that good optical performance can be achieved while being compact, having a wide angle, and having a large aperture. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a lens cross-sectional view showing a first configuration example (Example 1) of an imaging lens according to an embodiment of the present disclosure. [Figure 2]4 is an aberration diagram showing longitudinal aberration of the imaging lens according to Example 1 when focused on infinity. FIG. [Figure 3] 4 is an aberration diagram showing longitudinal aberration of the imaging lens according to Example 1 when focusing on a close distance. FIG. [Figure 4] 4 is an aberration diagram showing lateral aberration of the imaging lens according to Example 1 when focused on infinity. FIG. [Figure 5] 4 is an aberration diagram showing lateral aberration of the imaging lens according to Example 1 when focusing on a close distance. FIG. [Figure 6] FIG. 10 is a lens cross-sectional view showing a second configuration example (Example 2) of an imaging lens according to an embodiment. [Figure 7] 10 is an aberration diagram showing longitudinal aberration of the imaging lens according to Example 2 when focused on infinity. FIG. [Figure 8] 10 is an aberration diagram showing longitudinal aberration of the imaging lens according to Example 2 when focusing on a close distance. FIG. [Figure 9] 10 is an aberration diagram showing lateral aberration of the imaging lens according to Example 2 when focused on infinity. FIG. [Figure 10] 10 is an aberration diagram showing lateral aberration of the imaging lens according to Example 2 when focusing on a close distance. FIG. [Figure 11] FIG. 10 is a lens cross-sectional view showing a third configuration example (Example 3) of an imaging lens according to an embodiment. [Figure 12] 10 is an aberration diagram showing longitudinal aberration of the imaging lens according to Example 3 when focused on infinity. FIG. [Figure 13] 10 is an aberration diagram showing longitudinal aberration of the imaging lens according to Example 3 when focusing on a close distance. FIG. [Figure 14] 10 is an aberration diagram showing lateral aberration of the imaging lens according to Example 3 when focused on infinity. FIG. [Figure 15] 10A and 10B are aberration diagrams showing lateral aberrations of the imaging lens according to Example 3 when focusing on a close distance. [Figure 16] FIG. 10 is a lens cross-sectional view showing a fourth configuration example (Example 4) of an imaging lens according to an embodiment. [Figure 17] 10 is an aberration diagram showing longitudinal aberration of the imaging lens according to Example 4 when focused on infinity. FIG. [Figure 18] 10 is an aberration diagram showing longitudinal aberration of the imaging lens according to Example 4 when focusing on a close distance. FIG. [Figure 19] 10 is an aberration diagram showing lateral aberration of the imaging lens according to Example 4 when focused on infinity. FIG. [Figure 20] 10 is an aberration diagram showing lateral aberration of the imaging lens according to Example 4 when focusing on a close distance. FIG. [Figure 21] FIG. 10 is a lens cross-sectional view showing a fifth configuration example (Example 5) of an imaging lens according to an embodiment. [Figure 22] 10 is an aberration diagram showing longitudinal aberration of the imaging lens according to Example 5 when focused on infinity. FIG. [Figure 23] 10 is an aberration diagram showing longitudinal aberration of the imaging lens according to Example 5 when focusing on a close distance. FIG. [Figure 24] 10 is an aberration diagram showing lateral aberration of the imaging lens according to Example 5 when focused on infinity. FIG. [Figure 25] 10 is an aberration diagram showing lateral aberration of the imaging lens according to Example 5 when focusing on a close distance. FIG. [Figure 26] FIG. 1 is a block diagram illustrating an example of the configuration of an imaging device. [Figure 27] 1 is a block diagram showing an example of a schematic configuration of a vehicle control system; [Figure 28] FIG. 2 is an explanatory diagram showing an example of the installation positions of an outside-vehicle information detection unit and an imaging unit. [Figure 29] FIG. 1 is a diagram illustrating an example of a schematic configuration of an endoscope system. [Figure 30] FIG. 30 is a block diagram showing an example of the functional configuration of the camera and the CCU shown in FIG. 29. [Figure 31] FIG. 1 is a diagram illustrating an example of a schematic configuration of a microsurgery system. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The description will be made in the following order. 0. Comparative Example 1. Basic lens structure 2. Action and Effects 3. Application example to imaging devices 4. Numerical examples of lenses 5. Application Examples 6. Other embodiments

[0011] <0. Comparative Example> The imaging lens described in Patent Document 1 (JP 2002-303791 A) employs a retrofocus type and positions a focusing group immediately before the lens positioned closest to the image plane, thereby achieving a compact size and suppressing aberration fluctuations during focusing. However, the imaging lens described in Patent Document 1 has a folding reflecting member for compactness, and if the imaging element is further enlarged, the radial constraints become very strict, making it difficult to maintain compactness. Furthermore, if a wider angle and larger aperture are attempted while maintaining the radial constraints, the refractive power of each lens group becomes too strong, making it difficult to correct aberrations.

[0012] The imaging lens described in Patent Document 2 (WO 2011 / 027690) is composed of, in order from the object side, a first lens group, a second lens group, and a third lens group. By moving the second lens group in the optical axis direction during focusing, the number of lenses is reduced to approximately three to five, allowing for compactness and suppressing aberration fluctuations during focusing. However, in the imaging lens described in Patent Document 2, the first lens group is composed of two lenses. Further widening the angle of view makes the first lens group larger, making it difficult to maintain compactness. Furthermore, as the aperture becomes larger, optimizing the power of the first lens group to correct spherical aberrations becomes more difficult. Furthermore, the burden of off-axis residual aberrations that cannot be fully corrected by the first lens group must be corrected by the third lens group, which is composed of one or two lenses, including an aspherical lens, making it extremely difficult to achieve both optical performance and manufacturability.

[0013] <1. Basic lens configuration> FIG. 1 shows a first configuration example of an imaging lens according to an embodiment of the present disclosure, which corresponds to the configuration of Example 1 described later. FIG. 6 shows a second configuration example of an imaging lens according to an embodiment, which corresponds to the configuration of Example 2 described later. FIG. 11 shows a third configuration example of an imaging lens according to an embodiment, which corresponds to the configuration of Example 3 described later. FIG. 16 shows a fourth configuration example of an imaging lens according to an embodiment, which corresponds to the configuration of Example 4 described later. FIG. 21 shows a fifth configuration example of an imaging lens according to an embodiment, which corresponds to the configuration of Example 5 described later.

[0014] 1 and other figures, Z1 indicates the optical axis. An optical member such as a cover glass for protecting the imaging element may be disposed between the imaging lenses 1 to 5 according to the first to fifth configuration examples and the image plane. In addition to the cover glass, various optical filters (filters FL) such as a low-pass filter or an infrared cut filter may also be disposed as optical members.

[0015] The configuration of an imaging lens according to an embodiment of the present disclosure will be described below by appropriately associating it with imaging lenses 1 to 5 according to the configuration examples shown in FIG. 1 etc., however, the technology according to the present disclosure is not limited to the configuration examples shown in the drawings.

[0016] An imaging lens according to one embodiment is configured so that, arranged in order from the object side to the image plane side, are a first lens group G1 having positive refractive power, a second lens group G2 having positive refractive power, and a third lens group G3 having negative refractive power.

[0017] The first lens group G1 has a first aspherical lens with negative refractive power closest to the object side. During focusing, the second lens group G2 moves on the optical axis.

[0018] Here, in the imaging lens according to one embodiment, a "lens group" refers to a lens group that has refractive power and whose spacing between adjacent lens groups changes during focusing. A lens group that is composed solely of flat plates and has no refractive power is not defined as a lens group.

[0019] In addition, the imaging lens according to one embodiment may further satisfy certain conditional expressions, etc., which will be described later.

[0020] <2. Actions and Effects> Next, the functions and effects of the imaging lens according to the embodiment of the present disclosure will be described, along with a more preferable configuration of the imaging lens according to the embodiment of the present disclosure, and the functions and effects thereof. The effects described in this specification are merely examples and are not limiting, and other effects may also be present.

[0021] According to an embodiment of the imaging lens, the configuration of each lens group is optimized so that it is possible to achieve good optical performance while being compact, wide-angle, and large-aperture. This makes it possible to provide an imaging lens that is compact, wide-angle, and large-aperture, yet capable of achieving good optical performance, and an imaging device that includes such an imaging lens.

[0022] In an imaging lens according to one embodiment, the aperture stop St may be located closer to the image plane than the first aspherical lens in the first lens group G1. The first aspherical lens may be a lens L11 having negative refractive power. By locating the aperture stop St behind the first aspherical lens with negative refractive power that is located closest to the object, it is possible to achieve a compact size despite a large aperture. Furthermore, by using an aspherical lens as the lens L11 located closest to the object in the first lens group G1 and optimizing its refractive power, it is possible to effectively correct off-axis aberrations such as field curvature even at a wide angle.

[0023] The imaging lens according to one embodiment may satisfy the following conditional expression (1). -2.5 <f1 / f<-1.0 ……(1) however, f1: focal length of the first aspherical lens (lens L11) located closest to the object in the first lens group G1 f: focal length of the entire system Let's say.

[0024] Conditional formula (1) was established to achieve a compact optical system with high performance, and is a conditional formula for appropriately setting the focal length of lens L11, which is located closest to the object, relative to the focal length of the entire system. If the lower limit of conditional formula (1) is exceeded, the negative refractive power of lens L11 becomes small, making it difficult to reduce the effective diameter of lens L11 and widen the angle of view. On the other hand, if the upper limit of conditional formula (1) is exceeded, the axial light beam strongly diverged by lens L11 is incident on a lens behind aperture stop St, making it difficult to correct spherical aberration and coma. This also leads to an increase in the aperture diameter, making it difficult to reduce the size of the entire optical system.

[0025] Furthermore, by setting the numerical range of conditional expression (1) to the following conditional expressions (1A) and (1B), a better effect can be obtained. -2.0 <f1 / f<-1.0 ……(1A) -1.5 <f1 / f<-1.0 ……(1B)

[0026] Furthermore, the imaging lens according to one embodiment may satisfy the following conditional expression (2). -0.41 <f1 / LT<-0.2 ……(2) however, f1: focal length of the first aspherical lens (lens L11) located closest to the object in the first lens group G1 LT: Optical total length Let's say.

[0027] Conditional expression (2) is established to ensure that the optical system is compact and lightweight, and is a conditional expression for appropriately setting the relationship between the focal length of the first aspherical lens (lens L11) located closest to the object in the first lens group G1 and the overall optical length. If the lower limit of conditional expression (2) is not met, the focal length of the first aspherical lens located closest to the object in the first lens group G1 becomes too long, making it difficult to achieve a wide angle of view. On the other hand, if the upper limit of conditional expression (2) is exceeded, the overall length becomes too long, which increases the asymmetry in the power arrangement required for a wide angle of view, making it difficult to correct various aberrations and achieve high image quality.

[0028] Furthermore, by setting the numerical range of conditional expression (2) to the following conditional expressions (2A) and (2B), a better effect can be obtained. -0.38 <f1 / LT<-0.2 ……(2A) -0.36 <f1 / LT<-0.2 ……(2B)

[0029] Furthermore, the imaging lens according to one embodiment may have an aperture stop St and may satisfy the following conditional expression (3). 0.6 <LST / LT<1.0 ……(3) however, LST: Distance from aperture stop St to image plane LT: Optical total length Let's say.

[0030] Conditional expression (3) is established to suppress off-axis aberrations and achieve compactness, and defines the relationship between the distance from the aperture stop St to the image plane and the total optical length. If the lower limit of conditional expression (3) is exceeded, the entrance pupil position becomes too far from the object-side surface of the lens L11 located closest to the object, resulting in a large lens diameter for lens L11. On the other hand, if the upper limit of conditional expression (3) is exceeded, not only does the lens diameter of the lens located closer to the image plane than the aperture stop St become large, but it also makes it difficult to correct off-axis aberrations occurring in the lens L11 located closest to the object. Adding a lens near the image plane to compensate for insufficient correction of off-axis aberrations increases the total optical length, which is undesirable because it impacts compactness.

[0031] Furthermore, by setting the numerical range of conditional expression (3) to the following conditional expressions (3A) and (3B), a better effect can be obtained. 0.7 <LST / LT<0.9 ……(3A) 0.8 <LST / LT<0.9 ……(3B)

[0032] Furthermore, the imaging lens according to an embodiment may satisfy the following conditional expression (4). -0.8 <f2 / f3<-0.2 ……(4) however, f2: Focal length of the second lens group G2 f3: Focal length of the third lens group G3 Let's say.

[0033] Conditional expression (4) is defined to suppress image plane fluctuations during focusing while contributing to compactness, and is a conditional expression for appropriately setting the ratio between the focal length of the second lens group G2, which serves as a focus lens group, and the focal length of the third lens group G3, which is the lens group closest to the image plane. 4 ), if the lower limit of conditional expression () is not satisfied, the amount of movement during focusing becomes large, making it difficult to ensure sufficient spacing before and after the focus lens group. Also, the refractive power of the third lens group G3, which is the final lens group, becomes strong, making it difficult to correct off-axis aberrations such as curvature of field and astigmatism. 4 ) is exceeded, the refractive power of the focus lens group becomes too strong, making it difficult to suppress image plane fluctuations at close range.

[0034] Furthermore, by setting the numerical range of conditional expression (4) to the following conditional expressions (4A) and (4B), a better effect can be obtained. -0.7 <f2 / f3<-0.3 ……(4A) -0.6 <f2 / f3<-0.3 ……(4B)

[0035] In the imaging lens according to one embodiment, the first lens group G1 may further include a second aspherical lens (lens L13) having positive refractive power, in which case the following conditional expression (5) may be satisfied: 65<νd(1G)<85 ……(5) however, νd(1G): Abbe number for the d-line of the second aspherical lens (lens L13) Let's say.

[0036] Conditional expression (5) is defined to minimize the number of lenses while effectively correcting chromatic aberration, and is a conditional expression for appropriately setting the Abbe number of the second aspherical lens having positive refractive power in the first lens group G1. If the lower limit of conditional expression (5) is exceeded, it becomes difficult to correct longitudinal chromatic aberration and lateral chromatic aberration. On the other hand, if the upper limit of conditional expression (5) is exceeded, it becomes difficult to correct longitudinal chromatic aberration and lateral chromatic aberration.

[0037] Furthermore, by setting the numerical range of conditional expression (5) to the following conditional expressions (5A) and (5B), a better effect can be obtained. 70<νd(1G)<85 ……(5A) 80<νd(1G)<85 ……(5B)

[0038] In an imaging lens according to an embodiment, the second lens group G2 may be composed of a single biconvex positive lens. In this case, the lens surfaces before and after the positive lens in the second lens group G2 may be concave relative to the positive lens. This configuration makes it possible to effectively correct curvature of field and coma of the upper ray.

[0039] <3. Application example to imaging device> Next, a specific example of application of the imaging lens according to an embodiment of the present disclosure to an imaging device will be described.

[0040] 26 shows an example of the configuration of an imaging device 100 to which an imaging lens according to an embodiment is applied. The imaging device 100 is, for example, a digital still camera, and includes a camera block 110, a camera signal processing unit 20, an image processing unit 30, an LCD (Liquid Crystal Display) 40, an R / W (Reader / Writer) 50, a CPU (Central Processing Unit) 60, an input unit 70, and a lens drive control unit 80.

[0041] The camera block 110 has an imaging function and includes an imaging lens 111 and an imaging element 112 such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor). The imaging element 112 converts an optical image formed by the imaging lens 111 into an electrical signal, and outputs an imaging signal (image signal) corresponding to the optical image. The imaging lenses 1 to 5 according to the configuration examples shown in FIG. 1 and the like can be used as the imaging lens 111.

[0042] The camera signal processing unit 20 performs various signal processing on the image signal output from the image sensor 112, such as analog-to-digital conversion, noise removal, image quality correction, and conversion into luminance and color difference signals.

[0043] The image processing unit 30 performs recording and playback processing of image signals, and performs compression, encoding, decompression and decoding processing of image signals based on a predetermined image data format, as well as conversion processing of data specifications such as resolution.

[0044] The LCD 40 has a function of displaying various data such as the operation status of the user on the input unit 70 and captured images. The R / W 50 writes image data encoded by the image processing unit 30 to the memory card 1000 and reads image data recorded on the memory card 1000. The memory card 1000 is, for example, a semiconductor memory that is detachable from a slot connected to the R / W 50.

[0045] The CPU 60 functions as a control processing unit that controls each circuit block provided in the imaging device 100, and controls each circuit block based on instruction input signals and the like from the input unit 70. The input unit 70 is made up of various switches and the like that are operated as required by the user. The input unit 70 is composed of, for example, a shutter release button for operating the shutter and a selection switch for selecting an operation mode, and is configured to output instruction input signals to the CPU 60 in response to user operations. The lens drive control unit 80 controls the drive of the lenses arranged in the camera block 110, and is configured to control motors and the like (not shown) that drive each lens of the imaging lens 111 based on control signals from the CPU 60.

[0046] The operation of the imaging device 100 will be described below. In a standby state for photographing, under the control of the CPU 60, an image signal corresponding to an image photographed by the camera block 110 is output to the LCD 40 via the camera signal processing unit 20 and displayed as a camera-through image. Furthermore, when an instruction input signal for zooming or focusing is input from the input unit 70, for example, the CPU 60 outputs a control signal to the lens drive control unit 80, and a predetermined lens of the imaging lens 111 moves under the control of the lens drive control unit 80.

[0047] When a shutter (not shown) of the camera block 110 is operated by an instruction input signal from the input unit 70, the captured image signal is output from the camera signal processing unit 20 to the image processing unit 30, where it is compressed and encoded and converted into digital data in a predetermined data format. The converted data is output to the R / W 50 and written to the memory card 1000.

[0048] Focusing is performed by the lens drive control unit 80 moving a predetermined lens of the imaging lens 111 based on a control signal from the CPU 60, for example, when the shutter release button on the input unit 70 is pressed halfway or fully pressed for recording (photographing).

[0049] When reproducing image data recorded on the memory card 1000, the R / W 50 reads out the specified image data from the memory card 1000 in response to an operation on the input unit 70, and the image processing unit 30 performs an expansion / decoding process. After that, the reproduced image signal is output to the LCD 40, and the reproduced image is displayed.

[0050] Although the above-described embodiment shows an example in which the imaging device is applied to a digital still camera, the application range of the imaging device is not limited to digital still cameras and can be applied to various other imaging devices. For example, the imaging device can be applied to digital single-lens reflex cameras, digital non-reflex cameras, digital video cameras, surveillance cameras, etc. Furthermore, the imaging device can be widely used as a camera unit of digital input / output devices such as mobile phones with built-in cameras and information terminals with built-in cameras. Furthermore, the imaging device can be applied to cameras with interchangeable lenses. [Example]

[0051] <4. Numerical examples of lenses> Next, specific numerical examples of the imaging lens according to an embodiment of the present disclosure will be described. Here, examples will be described in which specific numerical values ​​are applied to imaging lenses 1 to 5 according to the configuration examples shown in FIG. 1 etc.

[0052] The meanings of symbols used in the following tables and explanations are as follows: "Si" indicates the number of the i-th surface, with the symbols increasing sequentially from the object side. "ri" indicates the paraxial radius of curvature of the i-th surface (mm). "di" indicates the axial distance (mm) between the i-th surface and the (i+1)-th surface. "ndi" indicates the refractive index of the material of the optical element that makes up the i-th surface at the d-line (wavelength 587.6 nm). "νdi" indicates the Abbe number of the material of the optical element that makes up the i-th surface at the d-line. "φi" indicates the clear aperture (mm) of the i-th surface. A portion where the "ri" value is "∞" indicates a flat surface, an aperture surface, etc. "ASP" in the surface number (Si) column indicates that the surface is aspherical. "STO" in the surface number column indicates that an aperture stop St is located at the corresponding position. "OBJ" in the surface number column indicates that the surface is the object surface (subject surface). "IMG" in the surface number column indicates that the surface in question is the image plane. "f" indicates the focal length of the entire system (unit: mm). "Fno" indicates the maximum aperture (F-number). "ω" indicates the half angle of view (unit: °). "Y" indicates the image height (unit: mm). "L" indicates the total optical length (the distance on the optical axis from the surface closest to the object to the image plane IMG) (unit: mm).

[0053] Furthermore, some of the lenses used in the examples have aspherical lens surfaces. The aspherical shape is defined by the following formula. In the tables showing the aspherical coefficients described later, "Ei" is an exponential expression with the base 10, that is, "10 -i " For example, "0.12345E-05" represents "0.12345 x 10 -5 " represents.

[0054] (Aspherical formula) x=cy 2 / (1+(1-(1+k)c 2 y 2 ) 1 / 2 )+A4·y 4 +A6·y 6 +A8·y 8 +A10·y 10 +A12·y12 +A14·y 14 Here, the distance from the vertex of the lens surface along the optical axis (sag) is "x," the height in the direction perpendicular to the optical axis is "y," the paraxial curvature at the vertex of the lens surface (the reciprocal of the radius of curvature) is "c," and the conic constant is "k." A4, A6, A8, A10, A12, and A14 are the 4th-, 6th-, 8th-, 10th-, 12th-, and 14th-order aspheric coefficients, respectively.

[0055] [Example 1] Table 1 shows basic lens data for the imaging lens 1 according to Example 1 shown in FIG. 1. Table 2 shows the focal length f of the entire system, the F-number, the total angle of view 2ω, the image height Y, and the total optical length L of the imaging lens 1 according to Example 1. Table 3 shows data on surface spacings that are variable during focusing in the imaging lens 1 according to Example 1. Table 2 shows values ​​when the object distance (d0) is infinity. Table 3 shows values ​​when the object distance (d0) is infinity and when it is close. Table 4 shows values ​​of coefficients that represent the shape of the aspherical surface in the imaging lens 1 according to Example 1. Table 5 shows the first surface and focal length (unit: mm) of each lens group in the imaging lens 1 according to Example 1.

[0056] The imaging lens 1 according to Example 1 is configured to include, in order from the object side to the image plane side, a first lens group G1 having positive refractive power, a second lens group G2 having positive refractive power, and a third lens group G3 having negative refractive power. An aperture stop St is disposed within the first lens group G1. A filter FL is disposed between the third lens group G3 and the image plane.

[0057] When focusing from infinity to a close distance, the second lens group G2 moves toward the object side in the direction of the optical axis.

[0058] The first lens group G1 consists of, in order from the object side to the image plane side, lens L11, aperture stop St, lens L12, lens L13, and lens L14. Lens L11 is a first aspherical lens, and is a negative meniscus lens with aspherical surfaces on both sides, with its convex surface facing the object side. Lens L12 is a positive meniscus lens with its concave surface facing the object side. Lens L13 is a second aspherical lens, and is a positive lens with a biconvex shape and aspherical surfaces on both sides. Lens L14 is a negative meniscus lens with its convex surface facing the object side.

[0059] The second lens group G2 is made up of the lens L21, which is a positive biconvex lens.

[0060] The third lens group G3 is made up of a lens L31, which is a negative meniscus lens with its concave surface facing the object side.

[0061] The above configuration achieves a wide angle and large aperture while also achieving compactness.

[0062] [Table 1]

[0063] [Table 2]

[0064] [Table 3]

[0065] [Table 4]

[0066] [Table 5]

[0067] Fig. 2 shows longitudinal aberration of the imaging lens 1 according to Example 1 when focusing at infinity. Fig. 3 shows longitudinal aberration of the imaging lens 1 according to Example 1 when focusing at a close distance. Fig. 4 shows lateral aberration of the imaging lens 1 according to Example 1 when focusing at infinity. Fig. 5 shows lateral aberration of the imaging lens 1 according to Example 1 when focusing at a close distance.

[0068] Figures 2 and 3 show longitudinal aberrations, including spherical aberration, astigmatism (field curvature), and distortion. In the spherical aberration diagrams in Figures 2 and 3 and the lateral aberration diagrams in Figures 4 and 5, the solid line shows values ​​at the d-line (587.56 nm), the dashed-dotted line shows values ​​at the g-line (435.84 nm), and the dashed line shows values ​​at the C-line (656.27 nm). In the astigmatism diagrams in Figures 2 and 3, S shows values ​​at the sagittal image plane, and T shows values ​​at the tangential image plane. The astigmatism diagrams and distortion diagrams in Figures 2 and 3 show values ​​at the d-line. The same applies to the aberration diagrams in the other examples that follow.

[0069] As can be seen from each aberration diagram, the imaging lens 1 according to Example 1 has excellent correction of various aberrations and has excellent imaging performance.

[0070] [Example 2] Table 6 shows basic lens data for the imaging lens 2 according to Example 2 shown in FIG. 6. Table 7 shows values ​​for the focal length f of the entire system, the F-number, the total angle of view 2ω, the image height Y, and the total optical length L of the imaging lens 2 according to Example 2. Table 8 shows data on surface spacings that are variable during focusing in the imaging lens 2 according to Example 2. Table 7 shows values ​​when the object distance (d0) is infinity. Table 8 shows values ​​when the object distance (d0) is infinity and when it is close. Table 9 shows values ​​of coefficients that represent the shape of the aspherical surface in the imaging lens 2 according to Example 2. Table 10 shows the first surface and focal length (unit: mm) of each lens group in the imaging lens 2 according to Example 2.

[0071] The imaging lens 2 according to Example 2 is configured to include, in order from the object side to the image plane side, a first lens group G1 having positive refractive power, a second lens group G2 having positive refractive power, and a third lens group G3 having negative refractive power. An aperture stop St is disposed within the first lens group G1. A filter FL is disposed between the third lens group G3 and the image plane.

[0072] When focusing from infinity to a close distance, the second lens group G2 moves toward the object side in the direction of the optical axis.

[0073] The first lens group G1 consists of, in order from the object side to the image plane side, lens L11, aperture stop St, lens L12, lens L13, and lens L14. Lens L11 is a first aspherical lens, and is a negative meniscus lens with aspherical surfaces on both sides, with its convex surface facing the object side. Lens L12 is a positive meniscus lens with its concave surface facing the object side. Lens L13 is a second aspherical lens, and is a positive lens with a biconvex shape and aspherical surfaces on both sides. Lens L14 is a negative meniscus lens with its convex surface facing the object side.

[0074] The second lens group G2 is made up of a lens L21, which is a biconvex positive lens with aspherical surfaces on both sides.

[0075] The third lens group G3 is made up of a lens L31, which is a negative meniscus lens with its concave surface facing the object side.

[0076] The above configuration achieves a wide angle and large aperture while also achieving compactness.

[0077] [Table 6]

[0078] [Table 7]

[0079] [Table 8]

[0080] [Table 9]

[0081] [Table 10]

[0082] Fig. 7 shows longitudinal aberration of the imaging lens 2 according to Example 2 when focusing at infinity. Fig. 8 shows longitudinal aberration of the imaging lens 2 according to Example 2 when focusing at a close distance. Fig. 9 shows lateral aberration of the imaging lens 2 according to Example 2 when focusing at infinity. Fig. 10 shows lateral aberration of the imaging lens 2 according to Example 2 when focusing at a close distance.

[0083] As can be seen from each aberration diagram, the imaging lens 2 according to Example 2 has excellent correction of various aberrations and has excellent imaging performance.

[0084] [Example 3] Table 11 shows basic lens data for the imaging lens 3 according to Example 3 shown in FIG. 11. Table 12 shows the values ​​of the focal length f, F-number, total angle of view 2ω, image height Y, and total optical length L of the entire system of the imaging lens 3 according to Example 3. Table 13 shows data on surface spacings that are variable during focusing in the imaging lens 3 according to Example 3. Table 12 shows values ​​when the object distance (d0) is infinity. Table 13 shows values ​​when the object distance (d0) is infinity and when it is close. Table 14 shows values ​​of coefficients that represent the shape of the aspherical surface in the imaging lens 3 according to Example 3. Table 15 shows the first surface and focal length (unit: mm) of each lens group in the imaging lens 3 according to Example 3.

[0085] The imaging lens 3 according to Example 3 is configured to include, in order from the object side to the image plane side, a first lens group G1 having positive refractive power, a second lens group G2 having positive refractive power, and a third lens group G3 having negative refractive power. An aperture stop St is disposed within the first lens group G1. A filter FL is disposed between the third lens group G3 and the image plane.

[0086] When focusing from infinity to a close distance, the second lens group G2 moves toward the object side in the direction of the optical axis.

[0087] The first lens group G1 consists of, in order from the object side to the image plane side, lens L11, aperture stop St, lens L12, lens L13, and lens L14. Lens L11 is a first aspherical lens, and is a negative meniscus lens with aspherical surfaces on both sides, with its convex surface facing the object side. Lens L12 is a positive meniscus lens with its concave surface facing the object side. Lens L13 is a second aspherical lens, and is a positive lens with a biconvex shape and aspherical surfaces on both sides. Lens L14 is a negative biconcave lens.

[0088] The second lens group G2 is made up of the lens L21, which is a positive biconvex lens.

[0089] The third lens group G3 is made up of a lens L31, which is a negative meniscus lens with its concave surface facing the object side.

[0090] The above configuration achieves a wide angle and large aperture while also achieving compactness.

[0091] [Table 11]

[0092] [Table 12]

[0093] [Table 13]

[0094] [Table 14]

[0095] [Table 15]

[0096] Fig. 12 shows longitudinal aberration of the imaging lens 3 according to Example 3 when focusing at infinity. Fig. 13 shows longitudinal aberration of the imaging lens 3 according to Example 3 when focusing at a close distance. Fig. 14 shows lateral aberration of the imaging lens 3 according to Example 3 when focusing at infinity. Fig. 15 shows lateral aberration of the imaging lens 3 according to Example 3 when focusing at a close distance.

[0097] As can be seen from each aberration diagram, the imaging lens 3 according to Example 3 has excellent correction of various aberrations and has excellent imaging performance.

[0098] [Example 4] Table 16 shows basic lens data for the imaging lens 4 according to Example 4 shown in FIG. 16. Table 17 shows the focal length f of the entire system, the F-number, the total angle of view 2ω, the image height Y, and the total optical length L of the imaging lens 4 according to Example 4. Table 18 shows data on surface spacings that are variable during focusing in the imaging lens 4 according to Example 4. Table 17 shows values ​​when the object distance (d0) is infinity. Table 18 shows values ​​when the object distance (d0) is infinity and when the object distance is close. Table 19 shows values ​​of coefficients that represent the shape of the aspherical surface in the imaging lens 4 according to Example 4. Table 20 shows the first surface and focal length (unit: mm) of each lens group in the imaging lens 4 according to Example 4.

[0099] The imaging lens 4 according to Example 4 is configured to include, in order from the object side to the image plane side, a first lens group G1 having positive refractive power, a second lens group G2 having positive refractive power, and a third lens group G3 having negative refractive power. An aperture stop St is disposed within the first lens group G1. A filter FL is disposed between the third lens group G3 and the image plane.

[0100] When focusing from infinity to a close distance, the second lens group G2 moves toward the object side in the direction of the optical axis.

[0101] The first lens group G1 consists of, in order from the object side to the image plane side, lens L11, aperture stop St, lens L12, lens L13, and lens L14. Lens L11 is a first aspherical lens, and is a negative meniscus lens with aspherical surfaces on both sides, with its convex surface facing the object side. Lens L12 is a positive meniscus lens with its concave surface facing the object side. Lens L13 is a second aspherical lens, and is a positive lens with a biconvex shape and aspherical surfaces on both sides. Lens L14 is a negative biconcave lens.

[0102] The second lens group G2 is made up of a lens L21, which is a biconvex positive lens with aspherical surfaces on both sides.

[0103] The third lens group G3 is made up of a lens L31, which is a negative meniscus lens with its concave surface facing the object side.

[0104] The above configuration achieves a wide angle and large aperture while also achieving compactness.

[0105] [Table 16]

[0106] [Table 17]

[0107] [Table 18]

[0108] [Table 19]

[0109] [Table 20]

[0110] Fig. 17 shows longitudinal aberration of the imaging lens 4 according to Example 4 when focusing at infinity. Fig. 18 shows longitudinal aberration of the imaging lens 4 according to Example 4 when focusing at a close distance. Fig. 19 shows lateral aberration of the imaging lens 4 according to Example 4 when focusing at infinity. Fig. 20 shows lateral aberration of the imaging lens 4 according to Example 4 when focusing at a close distance.

[0111] As can be seen from each aberration diagram, the imaging lens 4 according to Example 4 has excellent correction of various aberrations and has excellent imaging performance.

[0112] [Example 5] Table 21 shows basic lens data for the imaging lens 5 according to Example 5 shown in FIG. 21. Table 22 shows the focal length f of the entire system, the F-number, the total angle of view 2ω, the image height Y, and the total optical length L of the imaging lens 5 according to Example 5. Table 23 shows data on surface spacings that are variable during focusing in the imaging lens 5 according to Example 5. Table 22 shows values ​​when the object distance (d0) is infinity. Table 23 shows values ​​when the object distance (d0) is infinity and when the object distance is close. Table 24 shows values ​​of coefficients that represent the shape of the aspherical surface in the imaging lens 5 according to Example 5. Table 25 shows the first surface and focal length (unit: mm) of each lens group in the imaging lens 5 according to Example 5.

[0113] The imaging lens 5 according to Example 5 is configured to include, in order from the object side to the image plane side, a first lens group G1 having positive refractive power, a second lens group G2 having positive refractive power, and a third lens group G3 having negative refractive power. An aperture stop St is disposed within the first lens group G1. A filter FL is disposed between the third lens group G3 and the image plane.

[0114] When focusing from infinity to a close distance, the second lens group G2 moves toward the object side in the direction of the optical axis.

[0115] The first lens group G1 consists of, in order from the object side to the image plane side, lens L11, aperture stop St, lens L12, lens L13, and lens L14. Lens L11 is a first aspherical lens, and is a negative meniscus lens with aspherical surfaces on both sides, with its convex surface facing the object side. Lens L12 is a positive meniscus lens with its concave surface facing the object side. Lens L13 is a second aspherical lens, and is a positive lens with a biconvex shape and aspherical surfaces on both sides. Lens L14 is a negative biconcave lens.

[0116] The second lens group G2 is made up of a lens L21, which is a biconvex positive lens with aspherical surfaces on both sides.

[0117] The third lens group G3 is made up of the lens L31, which is a negative biconcave lens.

[0118] The above configuration achieves a wide angle and large aperture while also achieving compactness.

[0119] [Table 21]

[0120] [Table 22]

[0121] [Table 23]

[0122] [Table 24]

[0123] [Table 25]

[0124] Fig. 22 shows longitudinal aberration of the imaging lens 5 according to Example 5 at the wide-angle end when focusing on infinity. Fig. 23 shows longitudinal aberration when focusing on a close distance. Fig. 24 shows lateral aberration of the imaging lens 5 according to Example 5 when focusing on infinity. Fig. 25 shows lateral aberration of the imaging lens 5 according to Example 5 when focusing on a close distance.

[0125] As can be seen from each aberration diagram, the imaging lens 5 according to Example 5 has excellent correction of various aberrations and has excellent imaging performance.

[0126] [Other numerical data for each example] Tables 26 and 27 show the values ​​for each of the above conditional expressions for each example. As can be seen from Tables 26 and 27, the values ​​for each example fall within the numerical range for each conditional expression.

[0127] [Table 26]

[0128] [Table 27]

[0129] <5. Application Examples> [5.1 First application example] The technology according to the present disclosure can be applied to various products. For example, the technology according to the present disclosure may be realized as a device mounted on any type of moving body, such as an automobile, an electric vehicle, a hybrid electric vehicle, a motorcycle, a bicycle, a personal mobility device, an airplane, a drone, a ship, a robot, a construction machine, or an agricultural machine (tractor).

[0130] 27 is a block diagram showing a schematic configuration example of a vehicle control system 7000, which is an example of a mobile object control system to which the technology according to the present disclosure can be applied. The vehicle control system 7000 includes a plurality of electronic control units connected via a communication network 7010. In the example shown in FIG. 27, the vehicle control system 7000 includes a drive system control unit 7100, a body system control unit 7200, a battery control unit 7300, an outside-vehicle information detection unit 7400, an inside-vehicle information detection unit 7500, and an integrated control unit 7600. The communication network 7010 connecting these multiple control units may be 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), or FlexRay (registered trademark).

[0131] Each control unit includes a microcomputer that performs arithmetic processing according to various programs, a storage unit that stores the programs executed by the microcomputer or parameters used in various calculations, and a drive circuit that drives various devices to be controlled. Each control unit includes a network I / F for communicating with other control units via a communication network 7010, and a communication I / F for communicating with devices or sensors inside and outside the vehicle via wired or wireless communication. Figure 27 illustrates the functional configuration of the integrated control unit 7600, including a microcomputer 7610, a general-purpose communication I / F 7620, a dedicated communication I / F 7630, a positioning unit 7640, a beacon receiving unit 7650, an in-vehicle device I / F 7660, an audio / video output unit 7670, an in-vehicle network I / F 7680, and a storage unit 7690. Similarly, the other control units also include a microcomputer, a communication I / F, a storage unit, and the like.

[0132] The drivetrain control unit 7100 controls the operation of devices related to the drivetrain of the vehicle in accordance with various programs. For example, the drivetrain control unit 7100 functions as a control device for a driving force generating device for generating driving force for the vehicle, such as an internal combustion engine or a drive motor, a driving force transmission mechanism for transmitting driving force to the wheels, a steering mechanism for adjusting the steering angle of the vehicle, and a braking device for generating braking force for the vehicle. The drivetrain control unit 7100 may also function as a control device for an ABS (Antilock Brake System) or an ESC (Electronic Stability Control), etc.

[0133] A vehicle state detection unit 7110 is connected to the drivetrain control unit 7100. The vehicle state detection unit 7110 includes at least one of a gyro sensor that detects the angular velocity of the axial rotational motion of the vehicle body, an acceleration sensor that detects the acceleration of the vehicle, or a sensor that detects the amount of operation of the accelerator pedal, the amount of operation of the brake pedal, the steering angle of the steering wheel, the engine rotation speed, the rotation speed of the wheels, etc. The drivetrain control unit 7100 performs arithmetic processing using signals input from the vehicle state detection unit 7110, and controls the internal combustion engine, the drive motor, the electric power steering device, the brake device, etc.

[0134] Body system control unit 7200 controls the operation of various devices mounted on the vehicle body in accordance with various programs. For example, body system control unit 7200 functions as a control device for a keyless entry system, a smart key system, a power window device, or various lamps such as head lamps, backup lamps, brake lamps, turn signals, and fog lamps. In this case, radio waves transmitted from a portable device that serves as a key or signals from various switches may be input to body system control unit 7200. Body system control unit 7200 receives these radio waves or signals and controls the vehicle's door lock device, power window device, lamps, etc.

[0135] The battery control unit 7300 controls the secondary battery 7310, which is the power supply source for the drive motor, in accordance with various programs. For example, information such as battery temperature, battery output voltage, or remaining battery capacity is input to the battery control unit 7300 from a battery device equipped with the secondary battery 7310. The battery control unit 7300 performs arithmetic processing using these signals, and controls the temperature regulation of the secondary battery 7310 or a cooling device or the like provided in the battery device.

[0136] The outside vehicle information detection unit 7400 detects information outside the vehicle equipped with the vehicle control system 7000. For example, at least one of an imaging unit 7410 and an outside vehicle information detection unit 7420 is connected to the outside vehicle information detection unit 7400. The imaging unit 7410 includes at least one of a ToF (Time Of Flight) camera, a stereo camera, a monocular camera, an infrared camera, and other cameras. The outside vehicle information detection unit 7420 includes at least one of an environmental sensor for detecting the current weather or climate, or a surrounding information detection sensor for detecting other vehicles, obstacles, pedestrians, etc. around the vehicle equipped with the vehicle control system 7000.

[0137] The environmental sensor may be, for example, at least one of a raindrop sensor that detects rain, a fog sensor that detects fog, a sunshine sensor that detects the degree of sunshine, and a snow sensor that detects snowfall. The surrounding information detection sensor may be at least one of an ultrasonic sensor, a radar device, and a LIDAR (Light Detection and Ranging, Laser Imaging Detection and Ranging) device. The imaging unit 7410 and the outside vehicle information detection unit 7420 may each be provided as an independent sensor or device, or may be provided as a device in which multiple sensors or devices are integrated.

[0138] 28 shows an example of the installation positions of the imaging unit 7410 and the vehicle exterior information detection unit 7420. The imaging units 7910, 7912, 7914, 7916, and 7918 are provided, for example, at least one of the front nose, side mirrors, rear bumper, back door, and upper part of the windshield inside the vehicle cabin of the vehicle 7900. The imaging unit 7910 provided on the front nose and the imaging unit 7918 provided on the upper part of the windshield inside the vehicle cabin mainly acquire images of the front of the vehicle 7900. The imaging units 7912 and 7914 provided on the side mirrors mainly acquire images of the sides of the vehicle 7900. The imaging unit 7916 provided on the rear bumper or back door mainly acquires images of the rear of the vehicle 7900. The imaging unit 7918 provided on the upper part of the windshield inside the vehicle cabin is mainly used to detect leading vehicles, pedestrians, obstacles, traffic lights, traffic signs, lanes, etc.

[0139] 28 shows an example of the imaging ranges of the imaging units 7910, 7912, 7914, and 7916. Imaging range a indicates the imaging range of imaging unit 7910 provided on the front nose, imaging ranges b and c indicate the imaging ranges of imaging units 7912 and 7914 provided on the side mirrors, respectively, and imaging range d indicates the imaging range of imaging unit 7916 provided on the rear bumper or back door. For example, by overlaying the image data captured by imaging units 7910, 7912, 7914, and 7916, a bird's-eye view image of vehicle 7900 viewed from above can be obtained.

[0140] The vehicle exterior information detection units 7920, 7922, 7924, 7926, 7928, and 7930 provided on the front, rear, sides, and corners of the vehicle 7900 and above the windshield inside the vehicle cabin may be, for example, ultrasonic sensors or radar devices. The vehicle exterior information detection units 7920, 7926, and 7930 provided on the front nose, rear bumper, back door, and above the windshield inside the vehicle cabin of the vehicle 7900 may be, for example, LIDAR devices. These vehicle exterior information detection units 7920 to 7930 are mainly used to detect preceding vehicles, pedestrians, obstacles, etc.

[0141] Returning to FIG. 27 , the explanation will be continued. The outside-vehicle information detection unit 7400 causes the imaging unit 7410 to capture an image outside the vehicle and receives the captured image data. The outside-vehicle information detection unit 7400 also receives detection information from the connected outside-vehicle information detection unit 7420. If the outside-vehicle information detection unit 7420 is an ultrasonic sensor, a radar device, or a LIDAR device, the outside-vehicle information detection unit 7400 emits ultrasonic waves or electromagnetic waves and receives information on the received reflected waves. The outside-vehicle information detection unit 7400 may perform object detection processing or distance detection processing for people, cars, obstacles, signs, text on the road, etc. based on the received information. The outside-vehicle information detection unit 7400 may also perform environment recognition processing for recognizing rainfall, fog, road conditions, etc. based on the received information. The outside-vehicle information detection unit 7400 may also calculate the distance to an object outside the vehicle based on the received information.

[0142] The outside vehicle information detection unit 7400 may also perform image recognition processing or distance detection processing to recognize people, vehicles, obstacles, signs, characters on the road, etc., based on the received image data. The outside vehicle information detection unit 7400 may perform processing such as distortion correction or alignment on the received image data, and may also generate an overhead image or a panoramic image by combining image data captured by different image capturing units 7410. The outside vehicle information detection unit 7400 may also perform viewpoint conversion processing using image data captured by different image capturing units 7410.

[0143] The interior information detection unit 7500 detects information inside the vehicle. A driver state detection unit 7510 that detects the state of the driver is connected to the interior information detection unit 7500, for example. The driver state detection unit 7510 may include a camera that captures an image of the driver, a biosensor that detects the driver's biometric information, or a microphone that collects sound from within the vehicle cabin. The biosensor is provided, for example, on the seat or steering wheel, and detects the biometric information of a passenger sitting in the seat or the driver gripping the steering wheel. The interior information detection unit 7500 may calculate the driver's level of fatigue or concentration, or determine whether the driver is dozing, based on the detection information input from the driver state detection unit 7510. The interior information detection unit 7500 may perform processing such as noise canceling on the collected audio signal.

[0144] The integrated control unit 7600 controls the overall operation of the vehicle control system 7000 in accordance with various programs. An input unit 7800 is connected to the integrated control unit 7600. The input unit 7800 may be implemented by a device that can be operated by a passenger, such as a touch panel, a button, a microphone, a switch, or a lever. Data obtained by voice recognition of a voice input through a microphone may be input to the integrated control unit 7600. The input unit 7800 may be, for example, a remote control device using infrared or other radio waves, or an externally connected device such as a mobile phone or a personal digital assistant (PDA) that can operate the vehicle control system 7000. The input unit 7800 may be, for example, a camera, in which case the passenger can input information by gestures. Alternatively, data obtained by detecting the movement of a wearable device worn by the passenger may be input. Furthermore, the input unit 7800 may include, for example, an input control circuit that generates an input signal based on information input by the passenger or the like using the input unit 7800 and outputs the input signal to the integrated control unit 7600. By operating this input unit 7800, passengers and the like input various data to the vehicle control system 7000 and instruct processing operations.

[0145] The storage unit 7690 may include a ROM (Read Only Memory) that stores various programs executed by the microcomputer, and a RAM (Random Access Memory) that stores various parameters, calculation results, sensor values, etc. The storage unit 7690 may also be realized by a magnetic storage device such as an HDD (Hard Disc Drive), a semiconductor storage device, an optical storage device, a magneto-optical storage device, or the like.

[0146] The general-purpose communication I / F 7620 is a general-purpose communication I / F that mediates communication between various devices present in the external environment 7750. The general-purpose communication I / F 7620 may implement a cellular communication protocol such as GSM (Global System of Mobile communications), WiMAX (registered trademark), LTE (Long Term Evolution), or LTE-Advanced (LTE-A), or other wireless communication protocols such as wireless LAN (also referred to as Wi-Fi (registered trademark)) or Bluetooth (registered trademark). The general-purpose communication I / F 7620 may connect to devices (e.g., application servers or control servers) present on an external network (e.g., the Internet, a cloud network, or an operator-specific network) via, for example, a base station or an access point. The general-purpose communication I / F 7620 may also connect to terminals present near the vehicle (e.g., terminals of drivers, pedestrians, or stores, or machine-type communication (MTC) terminals) using, for example, P2P (Peer to Peer) technology.

[0147] The dedicated communication I / F 7630 is a communication I / F that supports a communication protocol designed for use in vehicles. The dedicated communication I / F 7630 may implement a standard protocol such as WAVE (Wireless Access in Vehicle Environment), which is a combination of a lower layer IEEE802.11p and an upper layer IEEE1609, a dedicated short range communications (DSRC), or a cellular communication protocol. The dedicated communication I / F 7630 typically performs V2X communication, which is a concept including one or more of vehicle-to-vehicle communication, vehicle-to-infrastructure communication, vehicle-to-home communication, and vehicle-to-pedestrian communication.

[0148] The positioning unit 7640 performs positioning by receiving, for example, GNSS signals from GNSS (Global Navigation Satellite System) satellites (for example, GPS signals from GPS (Global Positioning System) satellites), and generates position information including the latitude, longitude, and altitude of the vehicle. Note that the positioning unit 7640 may identify the current position by exchanging signals with a wireless access point, or may obtain position information from a terminal such as a mobile phone, PHS, or smartphone that has a positioning function.

[0149] The beacon receiver 7650 receives, for example, radio waves or electromagnetic waves transmitted from radio stations or the like installed on the road, and acquires information such as the current location, congestion, road closures, required travel time, etc. The function of the beacon receiver 7650 may be included in the dedicated communication I / F 7630 described above.

[0150] The in-vehicle device I / F 7660 is a communication interface that mediates connections between the microcomputer 7610 and various in-vehicle devices 7760 present in the vehicle. The in-vehicle device I / F 7660 may establish a wireless connection using a wireless communication protocol such as wireless LAN, Bluetooth (registered trademark), NFC (Near Field Communication), or WUSB (Wireless USB). The in-vehicle device I / F 7660 may also establish a wired connection such as USB (Universal Serial Bus), HDMI (High-Definition Multimedia Interface), or MHL (Mobile High-Definition Link) via a connection terminal (and a cable, if necessary) not shown. The in-vehicle device 7760 may include, for example, at least one of a mobile device or a wearable device owned by a passenger, or an information device carried or installed in the vehicle. The in-vehicle device 7760 may also include a navigation device that searches for a route to a desired destination. The in-vehicle device I / F 7660 exchanges control signals or data signals with these in-vehicle devices 7760 .

[0151] The in-vehicle network I / F 7680 is an interface that mediates communication between the microcomputer 7610 and the communication network 7010. The in-vehicle network I / F 7680 transmits and receives signals in accordance with a predetermined protocol supported by the communication network 7010.

[0152] The microcomputer 7610 of the integrated control unit 7600 controls the vehicle control system 7000 in accordance with various programs based on information acquired via at least one of the general-purpose communication I / F 7620, the dedicated communication I / F 7630, the positioning unit 7640, the beacon receiving unit 7650, the in-vehicle device I / F 7660, and the in-vehicle network I / F 7680. For example, the microcomputer 7610 may calculate control target values ​​for the driving force generating device, the steering mechanism, or the braking device based on acquired information inside and outside the vehicle, and output control commands to the drivetrain control unit 7100. For example, the microcomputer 7610 may perform cooperative control aimed at realizing functions of an Advanced Driver Assistance System (ADAS), including vehicle collision avoidance or impact mitigation, following driving based on the following distance, vehicle speed maintenance driving, vehicle collision warning, vehicle lane departure warning, etc. In addition, the microcomputer 7610 may perform cooperative control for the purpose of autonomous driving, in which the vehicle travels autonomously without relying on driver operation, by controlling a driving force generating device, a steering mechanism, a braking device, etc. based on information acquired about the vehicle's surroundings.

[0153] The microcomputer 7610 may generate three-dimensional distance information between the vehicle and objects such as surrounding structures and people, and create local map information including information about the vicinity of the vehicle's current location, based on information acquired via at least one of the general-purpose communication I / F 7620, the dedicated communication I / F 7630, the positioning unit 7640, the beacon receiving unit 7650, the in-vehicle device I / F 7660, and the in-vehicle network I / F 7680. Furthermore, the microcomputer 7610 may predict dangers, such as a vehicle collision, the approach of a pedestrian, or entry into a closed road, based on the acquired information, and generate a warning signal. The warning signal may be, for example, a signal for generating a warning sound or turning on a warning lamp.

[0154] The audio / video output unit 7670 transmits at least one of audio and image output signals to an output device capable of visually or audibly notifying vehicle occupants or the outside of the vehicle of information. In the example of FIG. 27 , an audio speaker 7710, a display unit 7720, and an instrument panel 7730 are illustrated as output devices. The display unit 7720 may include, for example, at least one of an on-board display and a head-up display. The display unit 7720 may have an AR (Augmented Reality) display function. The output device may be other devices besides these devices, such as headphones, a wearable device such as an eyeglass-type display worn by the occupant, a projector, or a lamp. When the output device is a display device, the display device visually displays results obtained by various processes performed by the microcomputer 7610 or information received from other control units in various formats, such as text, images, tables, and graphs. When the output device is an audio output device, the audio output device converts audio signals consisting of reproduced audio data or acoustic data into analog signals and audibly outputs the analog signals.

[0155] In the example shown in FIG. 27 , at least two control units connected via the communication network 7010 may be integrated into one control unit. Alternatively, each control unit may be composed of multiple control units. Furthermore, the vehicle control system 7000 may include another control unit not shown. In the above description, some or all of the functions performed by one control unit may be assigned to another control unit. In other words, as long as information is transmitted and received via the communication network 7010, predetermined arithmetic processing may be performed by one of the control units. Similarly, a sensor or device connected to one control unit may be connected to another control unit, and multiple control units may transmit and receive detection information to and from each other via the communication network 7010.

[0156] In the vehicle control system 7000 described above, the imaging lens and imaging device of the present disclosure can be applied to the imaging unit 7410 and the imaging units 7910, 7912, 7914, 7916, and 7918.

[0157] [5.2 Second application example] The technology disclosed herein can be applied to a medical imaging system, which is a medical system that uses imaging technology, such as an endoscope system or a microscope system.

[0158] [Endoscope system] An example of an endoscopic system will be described with reference to FIGS. 29 and 30. FIG. 29 is a diagram illustrating an example of a schematic configuration of an endoscopic system 5000 to which the technology according to the present disclosure can be applied. FIG. 30 is a diagram illustrating an example of the configuration of an endoscope 5001 and a CCU (Camera Control Unit) 5039. FIG. 29 illustrates a state in which an operator (e.g., a doctor) 5067, who is a surgical participant, is performing surgery on a patient 5071 on a patient bed 5069 using the endoscopic system 5000. As shown in FIG. 29, the endoscopic system 5000 includes an endoscope 5001, which is a medical imaging device, a CCU 5039, a light source device 5043, a recording device 5053, an output device 5055, and a support device 5027 that supports the endoscope 5001.

[0159] In endoscopic surgery, an insertion aid called a trocar 5025 is inserted into a patient 5071. Then, a scope 5003 and surgical tools 5021 connected to an endoscope 5001 are inserted into the body of the patient 5071 via the trocar 5025. The surgical tools 5021 are, for example, energy devices such as an electric scalpel, forceps, etc.

[0160] A surgical image, which is a medical image showing the inside of the body of a patient 5071 photographed by an endoscope 5001, is displayed on a display device 5041. An operator 5067 performs a procedure on the surgical target using a surgical tool 5021 while viewing the surgical image displayed on the display device 5041. Note that the medical image is not limited to a surgical image, and may be a diagnostic image photographed during a diagnosis.

[0161] [Endoscopy] The endoscope 5001 is an imaging unit that captures images of the inside of the body of a patient 5071. For example, as shown in FIG. 30 , the endoscope 5001 is a camera 5005 that includes a focusing optical system 50051 that focuses incident light, a zoom optical system 50052 that enables optical zoom by changing the focal length of the imaging unit, a focus optical system 50053 that enables focus adjustment by changing the focal length of the imaging unit, and a light-receiving element 50054. The endoscope 5001 generates pixel signals by focusing light onto the light-receiving element 50054 via a connected scope 5003, and outputs the pixel signals to the CCU 5039 via a transmission system. The scope 5003 has an objective lens at its tip and is an insertion section that guides light from a connected light source device 5043 into the body of the patient 5071. The scope 5003 is, for example, a rigid scope if it is a rigid endoscope or a flexible scope if it is a flexible endoscope. The scope 5003 may be a direct endoscope or an oblique endoscope. Furthermore, the pixel signal may be a signal based on a signal output from a pixel, such as a RAW signal or an image signal. A configuration may also be adopted in which a memory is installed in the transmission system connecting the endoscope 5001 and the CCU 5039, and parameters related to the endoscope 5001 and the CCU 5039 are stored in the memory. The memory may be located, for example, at a connection portion of the transmission system or on a cable. For example, parameters at the time of shipment of the endoscope 5001 and parameters that change when power is applied may be stored in the memory of the transmission system, and the operation of the endoscope may be changed based on parameters read from the memory. The endoscope and the transmission system may be collectively referred to as an endoscope. The light receiving element 50054 is a sensor that converts received light into a pixel signal, and is, for example, a CMOS (Complementary Metal Oxide Semiconductor) type imaging element. It is preferable that the light receiving element 50054 be an imaging element capable of color imaging with a Bayer array. Furthermore, the light receiving element 50054 is preferably an imaging element having a number of pixels corresponding to a resolution of, for example, 4K (3840 horizontal pixels × 2160 vertical pixels), 8K (7680 horizontal pixels × 4320 vertical pixels), or square 4K (3840 or more horizontal pixels × 3840 or more vertical pixels). The light receiving element 50054 may be a single sensor chip or multiple sensor chips.For example, a prism may be provided to separate incident light into predetermined wavelength bands, and each wavelength band may be imaged by a different light-receiving element. Alternatively, multiple light-receiving elements may be provided for stereoscopic vision. The light-receiving element 50054 may be a sensor including an image processing circuit within its chip structure, or a Time of Flight (ToF) sensor. The transmission system may be, for example, an optical fiber cable or wireless transmission. Wireless transmission may be performed via any means capable of transmitting pixel signals generated by the endoscope 5001. For example, the endoscope 5001 and the CCU 5039 may be connected wirelessly, or the endoscope 5001 and the CCU 5039 may be connected via a base station in the operating room. In this case, the endoscope 5001 may simultaneously transmit not only pixel signals but also information related to the pixel signals (e.g., pixel signal processing priority, synchronization signal, etc.). The endoscope may be configured such that the scope and camera are integrated, or a light-receiving element is provided at the tip of the scope.

[0162] [CCU (Camera Control Unit)] The CCU 5039 is a control device that comprehensively controls the connected endoscope 5001 and light source device 5043, and is, for example, an information processing device having an FPGA 50391, a CPU 50392, a RAM 50393, a ROM 50394, a GPU 50395, and an I / F 50396, as shown in FIG. 30 . The CCU 5039 may also comprehensively control the connected display device 5041, recording device 5053, and output device 5055. For example, the CCU 5039 controls the irradiation timing, irradiation intensity, and type of irradiation light source of the light source device 5043. The CCU 5039 also performs image processing such as development processing (e.g., demosaic processing) and correction processing on pixel signals output from the endoscope 5001, and outputs the processed pixel signals (e.g., images) to an external device such as the display device 5041. The CCU 5039 also transmits control signals to the endoscope 5001 to control the driving of the endoscope 5001. The control signal is, for example, information regarding imaging conditions such as the magnification and focal length of the imaging unit. The CCU 5039 may have an image down-conversion function and may be configured to be able to simultaneously output a high-resolution (e.g., 4K) image to the display device 5041 and a low-resolution (e.g., HD) image to the recording device 5053.

[0163] The CCU 5039 may also be connected to external devices (e.g., recording devices, display devices, output devices, and support devices) via an IP converter that converts signals into a predetermined communication protocol (e.g., IP (Internet Protocol)). The connection between the IP converter and the external device may be configured as a wired network, or a partial or entire network may be configured as a wireless network. For example, the IP converter on the CCU 5039 side may have a wireless communication function and transmit the received video to an IP switcher or an output-side IP converter via a wireless communication network such as a fifth-generation mobile communication system (5G) or a sixth-generation mobile communication system (6G).

[0164] [Light source device] The light source device 5043 is a device capable of emitting light in a predetermined wavelength band and includes, for example, multiple light sources and a light source optical system that guides the light from the multiple light sources. The light sources are, for example, a xenon lamp, an LED light source, or an LD light source. The light source device 5043 has, for example, LED light sources corresponding to the three primary colors R, G, and B, and emits white light by controlling the output intensity and output timing of each light source. The light source device 5043 may also include a light source that can emit special light used for special light observation, in addition to a light source that emits normal light used for normal light observation. The special light is light in a predetermined wavelength band different from the normal light used for normal light observation, such as near-infrared light (light with a wavelength of 760 nm or more), infrared light, blue light, or ultraviolet light. The normal light is, for example, white light or green light. Narrowband light observation, which is a type of special light observation, alternately emits blue light and green light, allowing high-contrast imaging of specific tissues, such as blood vessels on the surface of mucous membranes, by utilizing the wavelength-dependence of light absorption in body tissue. Furthermore, in fluorescence observation, which is a type of special light observation, excitation light that excites a drug injected into body tissue is irradiated and fluorescence emitted by the body tissue or the drug as a marker is received to obtain a fluorescence image, thereby making it easier for the surgeon to visualize body tissue that is difficult for the surgeon to visualize under normal light. For example, in fluorescence observation using infrared light, infrared light having an excitation wavelength band is irradiated onto a drug such as indocyanine green (ICG) injected into body tissue, and the fluorescence of the drug is received, making it easier to visualize the structure of body tissue and affected areas. Furthermore, in fluorescence observation, a drug (e.g., 5-ALA) that is excited by special light in the blue wavelength band and emits fluorescence in the red wavelength band may be used. The type of irradiated light for the light source device 5043 is set under the control of the CCU 5039. The CCU 5039 may have a mode in which normal light observation and special light observation are alternately performed by controlling the light source device 5043 and the endoscope 5001. In this case, it is preferable that information based on pixel signals obtained under special light observation be superimposed on pixel signals obtained under normal light observation. The special light observation may be infrared observation, which uses infrared light to see deeper than the surface of an organ, or multispectral observation using hyperspectral spectroscopy. Photodynamic therapy may also be combined.

[0165] [Recording Device] The recording device 5053 is a device, such as a recorder, that records pixel signals (e.g., images) acquired from the CCU 5039. The recording device 5053 records images acquired from the CCU 5039 on a HDD, an SDD, or an optical disk. The recording device 5053 may be connected to a network within the hospital so as to be accessible from devices outside the operating room. The recording device 5053 may also have an image down-conversion or up-conversion function.

[0166] [Display device] The display device 5041 is a device capable of displaying an image, such as a display monitor. The display device 5041 displays an image based on pixel signals acquired from the CCU 5039. The display device 5041 may also function as an input device that enables gaze recognition, voice recognition, and instruction input using gestures by including a camera and a microphone.

[0167] [Output device] The output device 5055 is a device, such as a printer, that outputs information acquired from the CCU 5039. The output device 5055 prints, for example, a print image based on the pixel signal acquired from the CCU 5039 onto paper.

[0168] [Support device] The support device 5027 is an articulated arm including a base 5029 having an arm control device 5045, an arm 5031 extending from the base 5029, and a holder 5032 attached to the tip of the arm 5031. The arm control device 5045 is configured with a processor such as a CPU and controls the drive of the arm 5031 by operating according to a predetermined program. The support device 5027 controls the position and posture of the endoscope 5001 held by the holder 5032, for example, by controlling parameters such as the length of each link 5035 constituting the arm 5031 and the rotation angle and torque of each joint 5033 using the arm control device 5045. This allows the endoscope 5001 to be changed to a desired position or posture, allowing the scope 5003 to be inserted into the patient 5071 and the observation area within the body to be changed. The support device 5027 functions as an endoscope support arm that supports the endoscope 5001 during surgery. This allows the support device 5027 to take the place of an assistant scopist who holds the endoscope 5001. The support device 5027 may also be a device that supports a microscope device 5301 (described later) and may also be called a medical support arm. The support device 5027 may be controlled autonomously by the arm control device 5045, or may be controlled by the arm control device 5045 based on user input. For example, the control method may be a master-slave method in which the support device 5027, which serves as a slave device (replica device) serving as a patient cart, is controlled based on the movement of a master device (primary device) that is an operator console located at the user's hand. The support device 5027 may also be remotely controlled from outside the operating room.

[0169] The above describes an example of the endoscope system 5000 to which the technology according to the present disclosure can be applied. For example, the technology according to the present disclosure may be applied to a microscope system.

[0170] [Microscope system] 31 is a diagram showing an example of a schematic configuration of a microsurgical system to which the technology according to the present disclosure can be applied. In the following description, the same components as those in the endoscope system 5000 are denoted by the same reference numerals, and redundant description thereof will be omitted.

[0171] 31 shows a schematic diagram of an operator 5067 performing surgery on a patient 5071 on a patient bed 5069 using a microsurgical system 5300. For simplicity, the illustration of the cart 5037 of the microsurgical system 5300 is omitted, and a microscope device 5301 that replaces the endoscope 5001 is simplified. However, the microscope device 5301 in this description may refer to the microscope unit 5303 provided at the tip of the link 5035, or may refer to the entire configuration including the microscope unit 5303 and the support device 5027.

[0172] As shown in Figure 31, during surgery, a microsurgical system 5300 is used to display an enlarged image of the surgical site captured by a microscope device 5301 on a display device 5041 installed in an operating room. The display device 5041 is installed in a position facing an operator 5067, who performs various procedures on the surgical site, such as resecting the affected area, while observing the state of the surgical site using the image displayed on the display device 5041. Microsurgical systems are used, for example, in ophthalmic surgery and brain surgery.

[0173] The above describes examples of an endoscopic system 5000 and a microsurgery system 5300 to which the technology of the present disclosure can be applied. Note that the systems to which the technology of the present disclosure can be applied are not limited to these examples. For example, the support device 5027 may support another observation device or another surgical tool at its tip instead of the endoscope 5001 or the microscope unit 5303. Examples of such other observation devices include forceps, a surgeon, an insufflation tube for insufflation, or an energy treatment tool for incising tissue or sealing blood vessels by cauterization. Supporting these observation devices and surgical tools with a support device allows them to be more stably fixed in position than when medical staff support them manually, and also reduces the burden on medical staff. The technology of the present disclosure may be applied to support devices that support components other than the microscope unit.

[0174] Of the configurations described above, the technology according to the present disclosure can be suitably applied to the camera 5005. In particular, the imaging lens according to the present disclosure can be suitably applied to at least some of the optical systems of the camera 5005: the focusing optical system 50051, the zoom optical system 50052, and the focus optical system 50053.

[0175] <6. Other embodiments> The technology according to the present disclosure is not limited to the above-described embodiment and examples, and various modifications are possible.

[0176] For example, the shapes and numerical values ​​of each part shown in the above embodiment and example are merely examples of specific embodiments for implementing this technology, and the technical scope of this technology should not be interpreted in a limited manner based on these.

[0177] Furthermore, for example, the configuration may include a number of lenses different from the number of lenses shown in the above embodiment and example, or may include a lens that has substantially no refractive power.

[0178] For example, the present technology can be configured as follows. According to the present technology having the following configuration, the configuration of each lens group is optimized so that it is possible to realize good optical performance while being compact, wide-angle, and large-diameter. This makes it possible to provide an imaging lens that is compact, wide-angle, and large-diameter, yet capable of achieving good optical performance, and an imaging device equipped with such an imaging lens.

[0179] [1] From the object side to the image plane side, a first lens group having positive refractive power; a second lens group having positive refractive power; a third lens group having negative refractive power; It consists of the first lens group has a first aspherical lens having negative refractive power, the first aspherical lens being closest to the object; During focusing, the second lens group moves along the optical axis, The following condition is satisfied: Imaging lens. -2.5 <f1 / f<-1.0 ……(1) however, f1: the focal length of the first aspherical lens arranged closest to the object in the first lens group f: focal length of the entire system Let's say. [2] Furthermore, the following condition is satisfied: The imaging lens according to [1] above. -0.41 <f1 / LT<-0.2 ……(2) however, f1: the lens arranged closest to the object side of the first lens group 1st Aspherical lens focal length LT: Optical total length Let's say. [3] an aperture stop; The following condition is satisfied: The imaging lens according to [1] or [2] above. 0.6 <LST / LT<1.0 ……(3) however, LST: distance from the aperture stop to the image plane LT: Optical total length Let's say. [4] The aperture stop is disposed in the first lens group closer to the image plane than the first aspherical lens. The imaging lens according to [3] above. [5] Furthermore, the following condition is satisfied: The imaging lens according to any one of [1] to [4] above. -0.8 <f2 / f3<-0.2 ……(4) however, f2: focal length of the second lens group f3: focal length of the third lens group Let's say. [6] the first lens group further includes a second aspherical lens having positive refractive power; The following condition is satisfied: The imaging lens according to any one of [1] to [5] above. 65<νd(1G)<85 ……(5) however, νd(1G): Abbe number for the d line of the second aspherical lens Let's say. [7] the second lens group is composed of one biconvex positive lens element, The front and rear lens surfaces of the second lens group sandwiching the positive lens are concave with respect to the positive lens. The imaging lens according to any one of [1] to [6] above. [8] an imaging element that outputs an imaging signal corresponding to an optical image formed by the imaging lens; The imaging lens is From the object side to the image plane side, a first lens group having positive refractive power; a second lens group having positive refractive power; a third lens group having negative refractive power; It consists of the first lens group has a first aspherical lens having negative refractive power, the first aspherical lens being closest to the object; During focusing, the second lens group moves along the optical axis, The following condition is satisfied: Imaging device. -2.5 <f1 / f<-1.0 ……(1) however, f1: the focal length of the first aspherical lens arranged closest to the object in the first lens group f: focal length of the entire system Let's say. [9] Further comprising a lens having substantially no refractive power. The imaging lens according to any one of [1] to [7] above.

[10] The imaging lens further comprises a lens having substantially no refractive power. The imaging device according to [8] above. [Explanation of symbols]

[0180] L11...lens (first aspherical lens), L13...lens (second aspherical lens), G1...first lens group, G2...second lens group, G3...third lens group, IMG...image plane, St...aperture stop, Z1...optical axis, 1-5...imaging lens, FL...filter, 110...camera block, 111...imaging lens, 112...imaging element, 20...camera signal processing unit, 30...image processing unit, 40...L CD, 50...R / W (reader / writer), 60...CPU, 70...input unit, 80...lens drive control unit, 100...imaging device, 1000...memory card, 5005...camera, 50051...light-collecting optical system, 50052...zoom optical system, 50053...focus optical system, 50054...light-receiving element, 7410...imaging unit, 7910, 7912, 7914, 7916, 7918...imaging unit.

Claims

1. From the object side to the image plane side, As a lens group, a first lens group having positive refractive power; a second lens group having positive refractive power; a third lens group having negative refractive power; It consists of the first lens group has a first aspherical lens having negative refractive power, the first aspherical lens being closest to the object; During focusing, the second lens group moves on the optical axis, the second lens group is composed of one biconvex positive lens element, the front and rear lens surfaces of the second lens group sandwiching the positive lens are configured so that their concave surfaces face the positive lens, Further, it has an aperture stop, The following condition is satisfied: Imaging lens. -2.5<f1 / f<-1.0...(1) 0.6<LST / LT<0.9...(3)' however, f1: focal length of the first aspherical lens arranged closest to the object in the first lens group f: focal length of the entire system LST: distance from the aperture stop to the image plane LT: Optical total length Let's say.

2. Furthermore, the following condition is satisfied: The imaging lens according to claim 1 . -0.41<f1 / LT<-0.2...(2) however, f1: focal length of the first aspherical lens arranged closest to the object in the first lens group LT: Optical total length Let's say.

3. The aperture stop is disposed in the first lens group closer to the image plane than the first aspherical lens. The imaging lens according to claim 1 .

4. Furthermore, the following condition is satisfied: The imaging lens according to claim 1 . -0.8<f2 / f3<-0.2...(4) however, f2: focal length of the second lens group f3: focal length of the third lens group Let's say.

5. the first lens group further includes a second aspherical lens having a positive refractive power; The following condition is satisfied: The imaging lens according to claim 1 . 65<νd(1G)<85...(5) however, νd(1G): Abbe number of the second aspherical lens with respect to the d line Let's say.

6. an imaging element that outputs an imaging signal corresponding to an optical image formed by the imaging lens; The imaging lens is From the object side to the image plane side, a first lens group having positive refractive power; a second lens group having positive refractive power; a third lens group having negative refractive power; It consists of the first lens group has a first aspherical lens having negative refractive power, the first aspherical lens being closest to the object; During focusing, the second lens group moves on the optical axis, the second lens group is composed of one biconvex positive lens element, the front and rear lens surfaces of the second lens group sandwiching the positive lens are configured so that their concave surfaces face the positive lens, Further, it has an aperture stop, The following condition is satisfied: Imaging device. -2.5<f1 / f<-1.0...(1) 0.6<LST / LT<0.9...(3)' however, f1: focal length of the first aspherical lens arranged closest to the object in the first lens group f: focal length of the entire system LST: distance from the aperture stop to the image plane LT: Optical total length Let's say.

7. Further comprising a lens having substantially no refractive power.

6. The imaging lens according to claim 1.

8. The imaging lens further comprises a lens having substantially no refractive power. The imaging device according to claim 6 .

Images