Image pickup lens and image pickup device

Abstract

An imaging lens (110) is provided with a lens system (10) in which a negative first lens (L1), a positive second lens (L2), a stop (STO), a positive third lens (L3), and a negative fourth lens (L4) are arranged in this order from the object side to the image surface side. The focal length f under the d line of the lens system (10), the focal length f1 of the first lens (L1), the focal length f4 of the fourth lens (L4), the Abbe numbers vd1-vd4 of the first to fourth lenses (L1-L4), the total length TTL of the lens system (10), and the maximum image height ImgH satisfy the following conditional expressions (1)-(6). 2 < f1 / f <-0.9 (1)-2.5 < f4 / f <-0.7 (2) vd1 > 40 (3) vd1 / vd2 > 1.2 (4) vd3 / vd4 > 1.4 (5) 2 < TTL / ImgH < 4 (6).

Description

Technical Field

[0001] The present invention relates to a camera lens and a camera device. Background Art

[0002] Generally speaking, a camera device is sometimes installed in a variety of electronic devices such as smartphones, distance sensors, and VR (Virtual Reality) glasses. Usually, the camera device has a camera lens and an imaging element, and the camera lens is used to form an image of the object on the imaging element by imaging the light reflected by the object, thereby acquiring an image of the object. The camera lens of such a camera device is sometimes composed of a plurality of lenses each having a positive or negative refractive power. In recent years, various studies have been conducted to widen the angle and miniaturize the camera lens having a plurality of lenses.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent No. 6049924

[0006] Patent Document 2: Japanese Patent No. 6501810 Summary of the invention

[0007] Problems to be solved by the invention

[0008] On the other hand, when photographing a subject in a dark place, for example, the imaging device sometimes images not only visible light but also near-infrared light. However, in an imaging device that images visible light and near-infrared light, the wavelength range of light to be passed through the imaging lens becomes larger, so there is a problem that it is difficult to fully correct chromatic aberration in the imaging lens.

[0009] That is, when the chromatic aberration of visible light is corrected only by the camera lens, the chromatic aberration in a wide wavelength range including near-infrared light cannot be fully corrected, and good imaging performance cannot be ensured. In addition, especially when a wide-angle camera lens is used to correct the chromatic aberration in a wide wavelength range, there is a tendency that the intervals between multiple lenses become wider and the total length of the camera lens becomes longer. As a result, there is also a problem that it is difficult to achieve the miniaturization of the front lens diameter and the shortening of the total length, and the miniaturization of the camera lens is hindered.

[0010] The present disclosure has been made in view of the above-mentioned problems, and an object of the present disclosure is to provide an imaging lens and an imaging device that can satisfactorily correct chromatic aberration while achieving a wide angle and miniaturization.

[0011] Solutions to the problem

[0012] According to one embodiment of the present disclosure, there is provided an imaging lens having a lens system, wherein the lens system is sequentially arranged from the object side to the image side: a first lens having a negative refractive power and a concave surface facing the image side, a second lens having a positive refractive power, an aperture, a third lens having a positive refractive power and a concave surface facing the object side, and a fourth lens having a negative refractive power. When the focal length of the lens system under the d-line is set to f, the focal length of the first lens is set to f1, the focal length of the fourth lens is set to f4, the Abbe numbers of the first to fourth lenses are set to νd1 to νd4, the total length of the lens system is set to TTL, and the maximum image height is set to ImgH, the lens system satisfies the following conditional expressions (1) to (6).

[0013] -2<f1 / f<-0.9···(1)

[0014] -2.5<f4 / f<-0.7···(2)

[0015] νd1>40···(3)

[0016] νd1 / νd2>1.2···(4)

[0017] νd3 / νd4>1.4···(5)

[0018] 2<TTL / ImgH<4···(6)

[0019] According to another aspect of the present disclosure, an imaging device includes the imaging lens having the above-described configuration.

[0020] Effects of the Invention

[0021] According to the imaging lens and imaging device of the present disclosure, it is possible to correct chromatic aberration well while achieving a wide angle and miniaturization. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a diagram showing the configuration of an imaging device according to one embodiment.

[0023] Figure 2 This is a diagram showing the structure of the imaging lens of Example 1.

[0024] Figure 3 1 and 2 are aberration diagrams of the imaging lens of Example 1.

[0025] Figure 4 It is a diagram showing the relative amount of light with respect to the image height of the imaging lens of Example 1.

[0026] Figure 5 This is a diagram showing the structure of the imaging lens of Example 2.

[0027] Figure 6 1 and 1 are aberration diagrams of the imaging lens of Example 2.

[0028] Figure 7 It is a diagram showing the relative amount of light with respect to the image height of the imaging lens of Example 2.

[0029] Figure 8 This is a diagram showing the structure of an imaging lens according to Example 3.

[0030] Fig. 9 1 and 1 are aberration diagrams of the imaging lens of Example 3.

[0031] Fig.10 It is a diagram showing the relative amount of light with respect to the image height of the imaging lens of Example 3.

[0032] Fig.11 This is a diagram showing the structure of an imaging lens according to Example 4.

[0033] Fig.12 1 and 1 are aberration diagrams of the imaging lens of Example 4.

[0034] Fig.13 It is a diagram showing the relative amount of light with respect to the image height of the imaging lens of Example 4.

[0035] Fig.14 This is a diagram showing the structure of the imaging lens of Example 5.

[0036] Fig.15 1 and 1 are aberration diagrams of the imaging lens of Example 5.

[0037] Fig.16 It is a diagram showing the relative amount of light with respect to the image height of the imaging lens of Example 5.

[0038] Fig.17 This is a diagram showing the structure of the imaging lens of Example 6.

[0039] Fig.18 1 and 1 are aberration diagrams of the imaging lens of Example 6.

[0040] Fig.19 It is a diagram showing the relative amount of light with respect to the image height of the imaging lens of Example 6.

[0041] Fig. 20 This is a diagram showing the structure of the imaging lens of Example 7.

[0042] Fig.21 1 and 1 are aberration diagrams of the imaging lens of Example 7.

[0043] Fig. 22 It is a diagram showing the relative amount of light with respect to the image height of the imaging lens of Example 7.

[0044] Explanation of symbols

[0045] 10, 11, 12, 13, 14, 15, 16, 17 Lens system

[0046] 20 Bandpass filter

[0047] 30 Camera Components

[0048] L1 1st lens

[0049] L2 2nd lens

[0050] L3 3rd lens

[0051] L4 4th lens

[0052] STO Aperture

[0053] 110 Camera Lens

[0054] 120 Image acquisition unit

[0055] 130 processors

[0056] 140 Memory

[0057] 150 Input and output unit DETAILED DESCRIPTION

[0058] Hereinafter, one embodiment of the present disclosure will be described with reference to the drawings. The embodiment described below is an example and is not to be construed as limiting the description.

[0059] [Composition of the imaging device]

[0060] Figure 1 This is a diagram showing the configuration of an imaging device according to one embodiment. Figure 1 The illustrated imaging device includes an imaging lens 110 , an image acquisition unit 120 , a processor 130 , a memory 140 , and an input / output unit 150 .

[0061] The imaging lens 110 allows light reflected by an object, which is a subject, to pass through the imaging lens 110 and forms an optical image of the object on an image plane. Specifically, the imaging lens 110 includes a lens system 10 , a bandpass filter 20 , and an imaging element 30 .

[0062] The lens system 10 includes, in order from the object side as a subject toward the image plane IA side of the image sensor 30 , a first lens L1 , a second lens L2 , an aperture STO, a third lens L3 , and a fourth lens L4 .

[0063] The first lens L1 has a lens surface S1 on the object side and a concave lens surface S2 on the image plane IA side. The first lens L1 is a lens having a negative refractive power and a concave surface facing the image plane IA side.

[0064] The second lens L2 has a lens surface S3 on the object side and a lens surface S4 on the image plane IA side. The second lens L2 is a lens having a positive refractive power.

[0065] The aperture STO adjusts the amount of light incident on the third lens L3 by changing the size of the opening at the central portion.

[0066] The third lens L3 has a lens surface S6 on the object side and a convex lens surface S7 on the image plane IA side. The third lens L3 is a lens having a convex surface facing the image plane IA side and having a positive refractive power.

[0067] The fourth lens L4 has a concave lens surface S8 on the object side and a lens surface S9 on the image plane IA side. The fourth lens L4 is a lens with a negative refractive power whose concave surface faces the object side.

[0068] It should be noted that the first to fourth lenses L1 to L4 included in the lens system 10 may each be formed of a single lens or may be formed by bonding a plurality of lenses together. The detailed configuration of the lens system 10 will be described in detail later.

[0069] The bandpass filter 20 allows visible light and near-infrared light to pass through the light passing through the lens system 10. That is, the bandpass filter 20 allows visible light and near-infrared light having a wavelength in the range of 400 to 960 nm, for example, to pass through the light passing through the lens system 10. It should be noted that the imaging lens 110 may also be formed in a configuration without the bandpass filter 20. In addition, an optical component such as a sealing glass for protecting the imaging element 30 may be arranged at the position of the bandpass filter 20.

[0070] The imaging element 30 acquires an optical image of the object by detecting the light irradiated on the image plane IA and converting it into an electrical signal. The imaging element 30 includes, for example, a CCD (Charge Coupled Device) sensor or a CMOS (Complementary Metal Oxide Semiconductor) sensor, and includes a light receiving element such as a photodiode on the image plane IA.

[0071] The image acquisition unit 120 generates an image of an object from the optical image acquired by the imaging lens 110 .

[0072] The processor 130 includes, for example, a CPU (Central Processing Unit), an FPGA (Field Programmable Gate Array), or a DSP (Digital Signal Processor), and controls the entire camera apparatus.

[0073] The memory 140 includes, for example, a RAM (Random Access Memory) or a ROM (Read Only Memory), and stores information used for information processing executed by the processor 130 .

[0074] The input / output unit 150 receives input from a user operation and outputs an image according to the user operation.

[0075] The image acquisition unit 120 , the processor 130 , the memory 140 , and the input / output unit 150 are connected via a bus so as to be able to transmit data such as images and control signals to each other.

[0076] [Configuration of Lens System 10]

[0077] As described above, the lens system 10 has the first lens L1, the second lens L2, the aperture STO, the third lens L3 and the fourth lens L4 in order from the object side to the image plane IA side. When the focal length of the lens system 10 under the d line is set to f, the focal length of the first lens L1 is set to f1, the focal length of the fourth lens L4 is set to f4, the Abbe numbers of the first to fourth lenses are set to νd1 to νd4, respectively, the total length of the lens system 10 is set to TTL, and the maximum image height is set to ImgH, the lens system 10 satisfies the following conditional expressions (1) to (6).

[0078] -2<f1 / f<-0.9···(1)

[0079] -2.5<f4 / f<-0.7···(2)

[0080] νd1>40···(3)

[0081] νd1 / νd2>1.2···(4)

[0082] νd3 / νd4>1.4···(5)

[0083] 2<TTL / ImgH<4···(6)

[0084] By making the lens system 10 satisfy the above-mentioned conditional expressions (1) to (6), the off-axis light that is greatly refracted by the negative first lens L1 can be guided to the image plane IA at a gentle angle by the positive second lens L2 and the third lens L3 arranged before and after the aperture STO. In addition, by arranging the aperture STO between the second lens L2 and the third lens L3, the cutoff amount of the off-axis light can be suppressed to a minimum while realizing the miniaturization of the front lens diameter, so that the peripheral light amount can be easily ensured. In other words, the wide-angle and miniaturization of the camera lens 110 can be sought.

[0085] Conditional expression (1) specifies the relationship between the focal length f1 of the first lens L1 and the focal length f under the d-line of the lens system 10. By making the ratio f1 / f of their focal lengths greater than the lower limit of conditional expression (1), the negative refractive power of the first lens L1 becomes moderately strong, and a wide angle of view can be ensured with a short total length TTL. On the other hand, by making the ratio f1 / f of the focal lengths less than the upper limit of conditional expression (1), the negative refractive power of the first lens L1 can be prevented from becoming too strong, and correction of off-axis aberrations can be achieved, resulting in good resolution performance.

[0086] It should be noted that the lower limit of conditional expression (1) is usually -2, preferably -1.8. In addition, the upper limit of conditional expression (1) is usually -0.9, preferably -1.1. Therefore, the focal length ratio f1 / f may be included in the range of, for example, greater than -2 and less than -0.9, or greater than -1.8 and less than -1.1.

[0087] Conditional expression (2) defines the relationship between the focal length f4 of the fourth lens L4 and the focal length f on the d-line of the lens system 10. By making the focal length ratio f4 / f satisfy conditional expression (2), the refractive power of the fourth lens L4 can be appropriately set, thereby correcting aberrations well.

[0088] It should be noted that the lower limit of conditional expression (2) is usually -2.5, preferably -2. In addition, the upper limit of conditional expression (2) is usually -0.7. Therefore, the focal length ratio f4 / f may be included in the range of, for example, greater than -2.5 and less than -0.7, or may be included in the range of greater than -2 and less than -0.7.

[0089] Conditional expression (3) defines the Abbe number vd1 of the first lens L1 at the d-line. By forming the first lens L1 using a material having a large Abbe number so that the height of the off-axis light becomes high, the occurrence of chromatic aberration of the off-axis light can be suppressed.

[0090] In addition, conditional expressions (4) and (5) specify the ratio of the Abbe numbers νd1 to νd4 of the first to fourth lenses L1 to L4. That is, conditional expression (4) specifies the lower limit of the ratio νd1 / νd2 of the Abbe numbers of the first lens L1 and the second lens L2 arranged in front of the aperture STO, and conditional expression (5) specifies the lower limit of the ratio νd3 / νd4 of the Abbe numbers of the third lens L3 and the fourth lens L4 arranged behind the aperture STO. By appropriately setting the Abbe numbers of the combination of the positive lens and the negative lens respectively arranged before and after the aperture STO as in conditional expressions (4) and (5), chromatic aberration can be well corrected over a wide wavelength range from visible light to near-infrared light.

[0091] It should be noted that the lower limit value of the conditional expression (4) is usually 1.2. In addition, the lower limit value of the conditional expression (5) is usually 1.4, preferably 1.7.

[0092] Conditional expression (6) defines the relationship between the total length TTL and the maximum image height ImgH of the lens system 10. By satisfying conditional expression (6), it is possible to correct aberrations well while miniaturizing the imaging lens 110.

[0093] It should be noted that the lower limit of conditional expression (6) is usually 2, preferably 2.2. In addition, the upper limit of conditional expression (6) is usually 4, preferably 3.6. Therefore, the ratio of total length to maximum image height TTL / ImgH may be within the range of, for example, greater than 2 and less than 4, or within the range of greater than 2.2 and less than 3.6.

[0094] When the distance between the lens surface S2 of the first lens L1 and the lens surface S3 of the second lens L2 is set to D12, the lens system 10 of the present embodiment can further satisfy the following conditional expression (7).

[0095] D12 / f<0.8···(7)

[0096] Conditional expression (7) defines the relationship between the air gap D12 between the first lens L1 and the second lens L2 and the focal length f of the lens system 10. By satisfying conditional expression (7), the height of the off-axis light passing through the first lens L1 can be suppressed, and the front lens diameter can be reduced.

[0097] When the entrance pupil diameter of the lens system 10 is defined as EPD, the lens system 10 of the present embodiment can further satisfy the following conditional expression (8).

[0098] f / EPD<2.8···(8)

[0099] Conditional expression (8) specifies the relationship between the focal length f and the entrance pupil diameter EPD of the lens system 10 on the d-line, and is a conditional expression that specifies the so-called F number. By satisfying conditional expression (8), even for a miniaturized and high-definition imaging element 30, the necessary amount of light can be ensured with a short exposure time.

[0100] When the focal length of the second lens L2 is set to f2, the lens system 10 of the present embodiment can further satisfy the following conditional expression (9).

[0101] 1<f2 / f<4···(9)

[0102] Conditional expression (9) specifies the relationship between the focal length f2 of the second lens L2 and the focal length f under the d-line of the lens system 10. By making the ratio f2 / f of their focal lengths greater than the lower limit of conditional expression (9), the refractive power of the second lens L2 will not become excessively strong, and the aberration generated in the second lens L2 can be suppressed, and the performance degradation caused by the decentering error can be reduced. On the other hand, by making the ratio f2 / f of the focal lengths less than the upper limit of conditional expression (9), when the refractive power of each of the second lens L2 and the third lens L3 is adjusted within an appropriate range, the positive refractive power required for enlarging the aperture and shortening the total length TTL can be obtained. Therefore, the performance degradation caused by the decentering error of the second lens L2 and the third lens L3 can be reduced.

[0103] It should be noted that the lower limit value of conditional expression (9) is usually 1, preferably 1.5. In addition, the upper limit value of conditional expression (9) is usually 4, preferably 3.5. Therefore, the focal length ratio f2 / f can be included in the range of greater than 1 and less than 4, or in the range of greater than 1.5 and less than 3.5.

[0104] When the focal length of the lens system 10 at a wavelength of 940 nm is defined as fir, the lens system 10 of the present embodiment can further satisfy the following conditional expression (10).

[0105] 0.92<fir / f<1.08···(10)

[0106] Conditional expression (10) defines the relationship between the focal length of the lens system 10 at line d and the focal length fir of the lens system 10 at a wavelength of 940 nm. By satisfying conditional expression (10), the deviation of the focal positions of visible light and near-infrared light is reduced, and changes in optical characteristics due to wavelength can be reduced.

[0107] As described above, according to this embodiment, the focal length, Abbe number, total length, and maximum image height in the lens system can be appropriately set to maintain a balance between wide-angle and miniaturization of the imaging lens and aberration correction in a wide wavelength range including visible light and near-infrared light. Therefore, chromatic aberration can be well corrected while achieving wide-angle and miniaturization.

[0108] Example

[0109] The following is an example of the imaging lens 110 of the present disclosure. Parameters used in each example are as follows: In the table of lens data and lens system specification data, "degree" is used as the unit of angle, and "mm" is used as the unit of length.

[0110] f: focal length of the lens system below line d

[0111] Fno: F number (= f / EPD)

[0112] ω: half field of view

[0113] ImgH: Maximum image height

[0114] TTL: Total optical length of the lens system (the distance on the optical axis from the object-side lens surface S1 of the first lens L1 to the image surface IA)

[0115] i: lens surface number (i = 1, ..., 4, 6, ..., 9)

[0116] Ri: radius of curvature of the i-th lens surface Si

[0117] Di: The center distance between the i-th lens surface Si and the (i+1)-th lens surface S(i+1)

[0118] nd: refractive index of lens material for d-line

[0119] νd: Abbe number of the lens material

[0120] It should be noted that surface number 5 corresponds to the surface of the aperture STO located between the lens surface S4 and the lens surface S6; surface number 10 corresponds to the surface on the object side of the bandpass filter 20; and surface number 11 corresponds to the surface on the image side of the bandpass filter 20. In addition, "INF" in the radius of curvature indicates that the surface is a plane.

[0121] In the following embodiments, all lens surfaces Si have an aspherical shape. Here, the aspherical shape can be represented by the distance (droop) X in the optical axis direction from the tangent plane of the surface vertex. When the height from the optical axis is set to H, the radius of curvature is set to R, the cone constant is set to K, and the m-th aspherical coefficient is set to Am, the droop X can be obtained by the following formula.

[0122] X=(H 2 / R) / [1+{1-(1+K)H 2 / R 2} 1 / 2 ]+ΣAm·H m

[0123] Therefore, the aspheric shape is determined by showing the value of the aspheric coefficient Am in the above aspheric formula. In the table of aspheric data shown below, the value of the aspheric coefficient "E±n" (n is a natural number) is expressed as an exponential with 10 as the base. That is, "E±n" means "×10 ±n ”.

[0124] [Example 1]

[0125] Figure 2 1 is a diagram showing the structure of the imaging lens 110 according to the first embodiment. Figure 2 It is shown in Figure 1 The lens system 10 shown corresponds to the lens system 11 , the bandpass filter 20 , and the image plane IA of the imaging element 30 .

[0126] in addition, Figure 3 for Figure 2 1 is an aberration diagram of the imaging lens 110. Figure 3 In the spherical aberration diagram, the single-dot chain line represents the aberration under the F line, the solid line represents the aberration under the d line, the short-dashed line represents the aberration under the C line, and the long-dashed line represents the aberration under near-infrared light with a wavelength of 940 nm.

[0127] in addition, Figure 4 It is shown Figure 2 Graph showing relative light amount with respect to image height of the imaging lens 110. The relative light amount indicates the ratio of the light amount at the image height position when the light amount at the optical axis position on the image plane IA is set to 100%.

[0128] The camera lens 110 of Example 1 has a lens system 11, which is configured in sequence from the object side to the image plane IA side: a first lens L1 with a convex surface facing the object side and a concave surface facing the image plane IA side and having negative refractive power; a second lens L2 with a convex surface facing the object side and a concave surface facing the image plane IA side and having positive refractive power; an aperture STO; a third lens L3 with a convex surface facing the object side and a convex surface facing the image plane IA side and having positive refractive power; and a fourth lens L4 with a concave surface facing the object side and a convex surface facing the image plane IA side and having negative refractive power.

[0129] Table 1 shows lens data of the imaging lens 110 of Example 1.

[0130] [Table 1]

[0131] Face number R D Nd vd 1 100.0000 0.2400 1.54449 56.33 2 0.6834 0.3208 3 1.3333 0.2878 1.66059 20.40 4 7.7504 0.1692 5(STO) INF 0.1379 6 4.0059 0.5911 1.54449 56.33 7 -0.3301 0.0860 8 -0.7486 0.2016 1.66059 20.40 9 -26.2805 0.3206 10 INF 0.4450 1.51680 64.20 11 INF 0.3000

[0132] In addition, the following Tables 2 and 3 show the aspherical surface data of the imaging lens 110 of Example 1. That is, Tables 2 and 3 show the conic constant K and the aspherical coefficient Am of the lens system 11 .

[0133] [Table 2]

[0134] Face number K A4 A6 A8 1 3.50781E+01 1.48734E+00 -4.32871E+00 6.53483E+00 2 -1.56691E+00 2.81835E+00 9.22514E-01 -8.17150E+01 3 5.80431E-01 2.81732E-01 -2.28208E+00 1.19051E+01 4 1.39477E+01 7.64650E+01 1.09105E+00 7.40468E+01 6 -1.09391E+01 -5.09351E-01 3.98773E+00 -5.85542E+01 7 2.26244E+00 1.88287E+00 3.23161E+01 1.87459E+02 8 3.43024E-02 8.75211E+00 -7.64309E+01 4.06478E+02 9 -2.00000E+01 2.68851E+00 -1.99339E+01 7.39659E+01

[0135] [Table 3]

[0136] Face number A10 A12 A14 A16 1 -5.95101E+00 3.09339E+00 -7.03862E-01 0.00000E+00 2 2.89815E+02 -4.14498E+02 2.19820E+02 0.00000E+00 3 -6.47802E+01 2.72733E+02 -4.15539E+02 0.00000E+00 4 1.81838E+02 4.15604E+02 0.00000E+00 0.00000E+00 6 2.90021E+02 -3.83381E+02 0.00000E+00 0.00000E+00 7 7.78158E+02 2.60357E+03 6.37012E+03 7.43837E+03 8 -1.41596E+03 3.06444E+03 -3.65770E+03 1.84165E+03 9 -1.73351E+02 2.51453E+02 -2.04267E+02 7.05611E+01

[0137] Table 4 below shows specification data of the lens system of Example 1. That is, Table 4 shows the focal length f, F number Fno, half angle of view ω, maximum image height ImgH, and total optical length TTL of the lens system 11 .

[0138] [Table 4]

[0139] f 0.85 Fno 2.40 ω 60.11 Ih 1.184 TTL 3.10

[0140] [Example 2]

[0141] Figure 5 1 is a diagram showing the structure of an imaging lens 110 according to Example 2. Figure 5 It is shown in Figure 1 The lens system 10 shown corresponds to a lens system 12 , a bandpass filter 20 , and an image plane IA of an image pickup element 30 .

[0142] in addition, Figure 6 for Figure 5 1 is an aberration diagram of the imaging lens 110. Figure 6 In the spherical aberration diagram, the single-dot chain line represents the aberration under the F line, the solid line represents the aberration under the d line, the short-dashed line represents the aberration under the C line, and the long-dashed line represents the aberration under near-infrared light with a wavelength of 940 nm.

[0143] in addition, Figure 7 It is shown Figure 5 Graph showing relative light amount with respect to image height of the imaging lens 110. The relative light amount indicates the ratio of the light amount at the image height position when the light amount at the optical axis position on the image plane IA is set to 100%.

[0144] The camera lens 110 of Example 2 has a lens system 12, which is configured in sequence from the object side to the image plane IA side: a first lens L1 with a convex surface facing the object side and a concave surface facing the image plane IA side and having a negative refractive power; a second lens L2 with a convex surface facing the object side and a convex surface facing the image plane IA side and having a positive refractive power; an aperture STO; a third lens L3 with a convex surface facing the object side and a convex surface facing the image plane IA side and having a positive refractive power; and a fourth lens L4 with a concave surface facing the object side and a concave surface facing the image plane IA side and having a negative refractive power.

[0145] Table 5 shows lens data of the imaging lens 110 of Example 2.

[0146] [Table 5]

[0147] Face number R D Nd vd 1 11.5331 0.2400 1.54449 56.33 2 0.6089 0.3577 3 1.2848 0.4057 1.58800 38.00 4 6.6218 0.2194 5(STO) INF 0.1668 6 3.0276 0.6386 1.54449 56.33 7 -0.3355 0.1003 8 -0.6686 0.2016 1.66059 20.40 9 23.5746 0.2250 10 INF 0.4450 1.51680 64.20 11 INF 0.3000

[0148] In addition, the following Tables 6 and 7 show the aspherical surface data of the imaging lens 110 of Example 2. That is, Tables 6 and 7 show the conic constant K and the aspherical coefficient Am of the lens system 12 .

[0149] [Table 6]

[0150] Face number K A4 A6 A8 1 -2.19604E+01 8.34467E-01 -1.83451E+00 1.94262E+00 2 -1.08278E+00 1.43009E+00 2.75447E+00 -3.32786E+01 3 -6.89451E-01 -1.29646E-01 1.13600E+00 -4.83138E+00 4 1.99359E+01 1.94254E+01 2.37091E+00 1.28941E+01 6 -1.62607E+01 -5.03328E-01 2.45254E+00 3.08694E+01 7 2.02532E+00 1.97943E+00 2.19295E+01 7.81116E+01 8 -3.42274E-01 7.38605E+00 -5.65625E+01 2.63174E+02 9 -2.00000E+01 1.67251E+00 -1.18500E+01 3.89057E+01

[0151] [Table 7]

[0152] Face number A10 A12 A14 A16 1 1.16928E+00 3.82463E+01 5.24479E+02 0.00000E+00 2 7.41396E+01 -6.98262E+01 2.50247E+01 0.00000E+00 3 9.14490E+00 -4.90081E+00 0.00000E+00 0.00000E+00 4 5.25366E+01 5.31088E+01 0.00000E+00 0.00000E+00 6 1.12883E+02 -9.72315E+01 0.00000E+00 0.00000E+00 7 -9.68611E+01 -1.40799E+02 2.92086E+02 1.66308E+02 8 7.94983E+02 1.49797E+03 1.55180E+03 6.69956E+02 9 7.85636E+01 9.67668E+01 6.57354E+01 1.87271E+01

[0153] In addition, the following Table 8 shows the specification data of the lens system of Example 2. That is, Table 8 shows the focal length f, F number Fno, half angle of view ω, maximum image height ImgH and total optical length TTL of the lens system 12.

[0154] [Table 8]

[0155] f 0.84 Fno 2.40 ω 60.11 Ih 1.184 TTL 3.30

[0156] [Example 3]

[0157] Figure 8 1 is a diagram showing the structure of an imaging lens 110 according to Example 3. Figure 8 It is shown in Figure 1 The lens system 10 shown corresponds to the lens system 13 , the bandpass filter 20 , and the image plane IA of the imaging element 30 .

[0158] in addition, Fig. 9 for Figure 8 1 is an aberration diagram of the imaging lens 110. Fig. 9 In the spherical aberration diagram, the single-dot chain line represents the aberration under the F line, the solid line represents the aberration under the d line, the short-dashed line represents the aberration under the C line, and the long-dashed line represents the aberration under near-infrared light with a wavelength of 940 nm.

[0159] in addition, Fig.10 It is shown Figure 8 Graph showing relative light amount with respect to image height of the imaging lens 110. The relative light amount indicates the ratio of the light amount at the image height position when the light amount at the optical axis position on the image plane IA is set to 100%.

[0160] The camera lens 110 of Example 3 has a lens system 13, which is configured in sequence from the object side to the image plane IA side: a first lens L1 with a convex surface facing the object side and a concave surface facing the image plane IA side and having negative refractive power; a second lens L2 with a convex surface facing the object side and a convex surface facing the image plane IA side and having positive refractive power; an aperture STO; a third lens L3 with a convex surface facing the object side and a convex surface facing the image plane IA side and having positive refractive power; and a fourth lens L4 with a concave surface facing the object side and a convex surface facing the image plane IA side and having negative refractive power.

[0161] Table 9 shows lens data of the imaging lens 110 of Example 3.

[0162] [Table 9]

[0163] Face number R D Nd vd 1 100.0000 0.2500 1.54449 56.33 2 0.6159 0.5301 3 1.4139 0.4381 1.58800 28.00 4 -4.2866 0.2575 5(STO) INF 0.1603 6 2.7906 0.6594 1.54449 56.33 7 -0.3361 0.0800 8 -0.4865 0.2000 1.66059 20.40 9 1.8595 0.2797 10 INF 0.4450 1.51680 64.20 11 INF 0.3000

[0164] In addition, the following Tables 10 and 11 show the aspherical surface data of the imaging lens 110 of Example 3. That is, Tables 10 and 11 show the conic constant K and the aspherical coefficient Am of the lens system 13 .

[0165] [Table 10]

[0166] Face number K A4 A6 A8 1 -4.00000E+01 4.66127E-01 -5.71227E-01 3.86531E-01 2 -8.18163E-01 8.62062E-01 -4.33849E-01 7.24109E+00 3 -1.66417E+00 -2.40522E-01 6.44013E-01 -2.31072E-01 4 1.88016E+01 1.26345E+01 2.47663E+00 9.43601E+00 6 4.14303E+01 7.07665E+01 5.23196E+00 4.36629E+01 7 3.13013E+00 1.37980E+00 1.38248E+01 1.05552E+02 8 -6.93337E-01 5.92498E+00 -2.69886E+01 9.36278E+01 9 -1.05980E+01 1.82302E-01 4.88991E+00 -3.03407E+01

[0167] [Table 11]

[0168] Face number A10 A12 A14 A16 1 1.88163E+01 5.75824E+02 7.54633E+03 0.00000E+00 2 -3.33913E+01 4.40102E+01 -1.86734E+01 0.00000E+00 3 2.84393E-01 -5.91840E-01 0.00000E+00 0.00000E+00 4 2.35517E+01 -2.20124E+01 0.00000E+00 0.00000E+00 6 1.32233E+02 -1.25008E+02 0.00000E+00 0.00000E+00 7 3.69334E+02 5.77241E+02 1.00830E+02 4.84237E+02 8 2.77808E+02 5.71857E+02 6.29058E+02 2.75691E+02 9 7.64744E+01 1.02762E+02 7.29381E+01 2.15592E+01

[0169] In addition, the following Table 12 shows the specification data of the lens system of Example 3. That is, Table 12 shows the focal length f, F number Fno, half angle of view ω, maximum image height ImgH and total optical length TTL of the lens system 13.

[0170] [Table 12]

[0171] f 0.76 Fno 2.20 ω 65.14 Ih 1.24 TTL 3.60

[0172] [Example 4]

[0173] Fig.11 1 is a diagram showing the structure of an imaging lens 110 according to Example 4. Fig.11 It is shown in Figure 1 The lens system 10 shown corresponds to a lens system 14 , a bandpass filter 20 , and an image plane IA of an image pickup element 30 .

[0174] in addition, Fig.12 for Fig.11 1 is an aberration diagram of the imaging lens 110. Fig.12In the spherical aberration diagram, the single-dot chain line represents the aberration under the F line, the solid line represents the aberration under the d line, the short-dashed line represents the aberration under the C line, and the long-dashed line represents the aberration under near-infrared light with a wavelength of 940 nm.

[0175] in addition, Fig.13 It is shown Fig.11 Graph showing relative light amount with respect to image height of the imaging lens 110. The relative light amount indicates the ratio of the light amount at the image height position when the light amount at the optical axis position on the image plane IA is set to 100%.

[0176] The camera lens 110 of Example 4 has a lens system 14, which is configured in sequence from the object side to the image plane IA side: a first lens L1 with a convex surface facing the object side and a concave surface facing the image plane IA side and having negative refractive power; a second lens L2 with a convex surface facing the object side and a concave surface facing the image plane IA side and having positive refractive power; an aperture STO; a third lens L3 with a convex surface facing the object side and a convex surface facing the image plane IA side and having positive refractive power; and a fourth lens L4 with a concave surface facing the object side and a convex surface facing the image plane IA side and having negative refractive power.

[0177] Table 13 shows lens data of the imaging lens 110 of Example 4.

[0178] [Table 13]

[0179] Face number R D Nd vd 1 1.6513 0.2500 1.51023 53.80 2 0.3865 0.2963 3 0.9513 0.5895 1.63218 23.70 4 3.6061 0.0840 5(STO) INF 0.0000 6 2.3205 0.7840 1.51023 53.80 7 -0.2861 0.0800 8 -0.6252 0.6804 1.63218 23.70 9 -15.7741 0.0909 10 INF 0.4450 1.51680 64.20 11 INF 0.2000

[0180] In addition, the following Tables 14 and 15 show the aspherical surface data of the imaging lens 110 of Example 4. That is, Tables 14 and 15 show the conic constant K and the aspherical coefficient Am of the lens system 14 .

[0181] [Table 14]

[0182] Face number K A4 A6 A8 1 3.63345E00 2.95702E01 1.84326E00 3.28485E100 2 1.18900E00 2.38480E00 6.92449E00 1.68381E01 3 6.29440E-02 5.52364E-01 -3.09223E+00 2.52526E+01 4 3.87319E+00 1.41895E+00 -9.22796E+00 2.35771E+02 6 1.31754E+01 -6.19017E-01 2.31492E+01 -4.26276E+02 7 -3.08284E+00 -2.09446E+00 9.82121E+00 -8.43350E+01 8 6.53563E+01 8.19409E+E01 2.51883E+00 5.47473E+00 9 4.00000E01 4.34272EE01 1.12920E00 1.53108E+00

[0183] [Table 15]

[0184] Face number A10 A12 A14 A16 1 -3.07608E+00 1.52475E+00 -3.12421E-01 0.00000E+00 2 8.70902E+01 -1.08863E+02 3.50679E+01 0.00000E+00 3 -1.31739E+02 3.61129E+02 -3.62567E+02 0.00000E+00 4 1.02852E+03 0.00000E+00 0.00000E+00 0.00000E+00 6 2.82851E+03 0.00000E+00 0.00000E+00 0.00000E+00 7 3.80098E+02 -9.32129E+02 1.00049E+03 0.00000E+00 8 -8.21537E+00 7.74314E+00 -4.10868E+00 9.31271E-01 9 -2.39122E+00 3.00388E+00 -2.14443E+00 6.25019E-01

[0185] Table 16 below shows the specification data of the lens system of Example 4. That is, Table 16 shows the focal length f, F number Fno, half angle of view ω, maximum image height ImgH, and total optical length TTL of the lens system 14 .

[0186] [Table 16]

[0187] f 0.85 Fno 2.40 0 60.12 Ih 1.184 TTL 3.50

[0188] [Example 5]

[0189] Fig.141 is a diagram showing the structure of an imaging lens 110 according to Example 5. Fig.14 It is shown in Figure 1 The lens system 10 shown corresponds to a lens system 15 , a bandpass filter 20 , and an image plane IA of an image pickup element 30 .

[0190] in addition, Fig.15 for Fig.14 1 is an aberration diagram of the imaging lens 110. Fig.15 In the spherical aberration diagram, the single-dot chain line represents the aberration under the F line, the solid line represents the aberration under the d line, the short-dashed line represents the aberration under the C line, and the long-dashed line represents the aberration under near-infrared light with a wavelength of 940 nm.

[0191] in addition, Fig.16 It is shown Fig.14 Graph showing relative light amount with respect to image height of the imaging lens 110. The relative light amount indicates the ratio of the light amount at the image height position when the light amount at the optical axis position on the image plane IA is set to 100%.

[0192] The camera lens 110 of Example 5 has a lens system 15, which is configured in sequence from the object side to the image plane IA side: a first lens L1 with a convex surface facing the object side and a concave surface facing the image plane IA side and having negative refractive power; a second lens L2 with a convex surface facing the object side and a convex surface facing the image plane IA side and having positive refractive power; an aperture STO; a third lens L3 with a convex surface facing the object side and a convex surface facing the image plane IA side and having positive refractive power; and a fourth lens L4 with a concave surface facing the object side and a convex surface facing the image plane IA side and having negative refractive power.

[0193] Table 17 shows lens data of the imaging lens 110 of Example 5.

[0194] [Table 17]

[0195] Face number R D Nd vd 1 20.8741 0.2500 1.54449 56.33 2 0.5285 0.4976 3 0.9967 0.5234 1.60792 26.90 4 9.4252 0.2776 5(STO) INF 0.0999 6 2.8770 0.6309 1.54449 56.33 7 -0.3218 0.0800 8 -0.5221 0.4194 1.66059 20.40 9 -3.4500 0.0763 10 1NF 0.4450 1.51680 64.20 11 INF 0.3000

[0196] In addition, the following Table 18 and Table 19 show the aspherical surface data of the imaging lens 110 of Example 5. That is, Table 18 and Table 19 show the conic constant K and the aspherical coefficient Am of the lens system 15.

[0197] [Table 18]

[0198] Face number K A4 A6 A8 1 1.19624E+01 1.32559E+01 6.41349E+02 7.57263E+03 2 8.81015E+01 1.37736E+02 2.51055E+01 7.09809E+00 3 -1.71585E+00 -2.52104E-01 1.06532E+00 -1.87914E+00 4 2.00000E+01 -4.00754E-02 1.40541E+00 -4.60979E+00 6 -1.60641E+01 -6.47173E-01 6.18028E+00 -1.28184E+02 7 2.60948E+00 9.65341E+01 2.07477E+01 7.98098E+01 8 6.45464E+01 7.99321E+00 7.79085E+01 4.92005E+02 9 5.69532E+00 8.13056E+01 7.80280E+00 3.45735E+01

[0199] [Table 19]

[0200] Face number A10 A12 A14 A16 1 1.35744E-02 -3.98228E-03 4.31769E-04 0.00000E+00 2 -1.91114E+01 1.67609E+01 -4.59073E+00 0.00000E+00 3 2.60360E+00 -1.42078E+00 0.00000E+00 0.00000E+00 4 1.10569E+01 9.51597E+00 0.00000E+00 0.00000E+00 6 8.83807E+02 2.05976E+03 0.00000E+00 0.00000E+00 7 1.87130E02 2.89087E03 9.16480E+03 9.37763E+03 8 -1.92133E+03 4.26717E+03 -4.72567E+03 1.91702E+03 9 -8.68653E+01 1.24557E+02 -9.56052E+01 3.07274E+01

[0201] Table 20 below shows the specification data of the lens system of Example 5. That is, Table 20 shows the focal length f, F number Fno, half angle of view ω, maximum image height ImgH, and total optical length TTL of the lens system 15 .

[0202] [Table 20]

[0203] f 0.75 Fno 2.50 ω 60.00 Ih 1.17 TTL 3.60

[0204] [Example 6]

[0205] Fig.17 1 is a diagram showing the structure of an imaging lens 110 according to Example 6. Fig.16 It is shown in Figure 1 The lens system 10 shown corresponds to a lens system 16 , a bandpass filter 20 , and an image plane IA of an image pickup element 30 .

[0206] in addition, Fig.18 for Fig.17 1 is an aberration diagram of the imaging lens 110. Fig.18 In the spherical aberration diagram, the single-dot chain line represents the aberration under the F line, the solid line represents the aberration under the d line, the short-dashed line represents the aberration under the C line, and the long-dashed line represents the aberration under near-infrared light with a wavelength of 940 nm.

[0207] in addition, Fig.19 It is shown Fig.17 Graph showing relative light amount with respect to image height of the imaging lens 110. The relative light amount indicates the ratio of the light amount at the image height position when the light amount at the optical axis position on the image plane IA is set to 100%.

[0208] The camera lens 110 of Example 6 has a lens system 16, which is configured in sequence from the object side to the image plane IA side: a first lens L1 with a convex surface facing the object side and a concave surface facing the image plane IA side and having negative refractive power; a second lens L2 with a convex surface facing the object side and a concave surface facing the image plane IA side and having positive refractive power; an aperture STO; a third lens L3 with a convex surface facing the object side and a convex surface facing the image plane IA side and having positive refractive power; and a fourth lens L4 with a concave surface facing the object side and a convex surface facing the image plane IA side and having negative refractive power.

[0209] Table 21 shows lens data of the imaging lens 110 of Example 6.

[0210] [Table 21]

[0211] Face number R D Nd vd 1 1.5896 0.3120 1.54449 56.33 2 0.5404 0.4441 3 1.6027 0.7842 1.60792 26.90 4 9.9925 0.1347 5(STO) INF 0.0000 6 3.0451 1.0560 1.54449 56.33 7 -0.4094 0.1040 8 -0.8146 0.8636 1.60792 26.90 9 -52.0000 0.0806 10 INF 0.5100 11 INF 0.3000

[0212] In addition, the following Table 22 and Table 23 show the aspherical surface data of the imaging lens 110 of Example 6. That is, Table 22 and Table 23 show the cone constant K and the aspherical coefficient Am of the lens system 16.

[0213] [Table 22]

[0214] Face number K A4 A6 A8 1 -3.30296E+00 2.31875E+00 -1.13468E+01 2.19707E+01 2 -1.06742E+00 2.15856E+00 -4.15493E+00 -2.47808E+00 3 1.09503E+00 5.65548E-01 -2.14305E+00 8.80505E+00 4 2.00000E+01 6.01299E+01 1.78684E+00 2.22430E+01 6 1.66499E+01 -2.60570E-01 4.97793E+00 -5.81424E+01 7 3.89831E+00 1.95972E+00 1.17525E+01 5.54044E+01 8 -4.53310E-01 2.91177E+00 -1.45804E+01 5.76346E+01 9 -4.00000E+01 3.05368E-02 2.47715E-01 -6.52976E-01

[0215] [Table 23]

[0216] Face number A10 A12 A14 A16 1 2.29295E+01 1.27593E+01 2.96718E+00 0.00000E+00 2 1.20712E+01 -1.08518E+01 3.15199E+00 0.00000E+00 3 -2.14277E+01 2.65733E+01 -1.28001E+01 0.00000E+00 4 -5.13066E+01 0.00000E+00 0.00000E+00 0.00000E+00 6 2.19441E+02 0.00000E+00 0.00000E+00 0.00000E+00 7 1.46584E+02 -2.08751E+02 1.24345E+02 0.00000E+00 8 1.72309E+02 3.32974E+02 3.66968E+02 1.73162E+02 9 6.05724E+01 2.81360E+01 5.88568E+02 2.88920E+03

[0217] Table 24 below shows specification data of the lens system of Example 6. That is, Table 24 shows the focal length f, F number Fno, half angle of view ω, maximum image height ImgH, and total optical length TTL of the lens system 16 .

[0218] [Table 24]

[0219] f 1.11 Fno 2.40 ω 60.11 Ih 1.54 TTL 4.59

[0220] [Example 7]

[0221] Fig. 20 1 is a diagram showing the structure of an imaging lens 110 according to Example 7. Fig. 20 It is shown in Figure 1 The lens system 10 shown corresponds to a lens system 17 , a bandpass filter 20 , and an image plane IA of an image pickup element 30 .

[0222] in addition, Fig.21 for Fig. 20 1 is an aberration diagram of the imaging lens 110. Fig.21 In the spherical aberration diagram, the single-dot chain line represents the aberration under the F line, the solid line represents the aberration under the d line, the short-dashed line represents the aberration under the C line, and the long-dashed line represents the aberration under near-infrared light with a wavelength of 940 nm.

[0223] in addition, Fig. 22 It is shown Fig. 20 Graph showing relative light amount with respect to image height of the imaging lens 110. The relative light amount indicates the ratio of the light amount at the image height position when the light amount at the optical axis position on the image plane IA is set to 100%.

[0224] The camera lens 110 of Example 7 has a lens system 17, which is configured in order from the object side to the image plane IA side: a first lens L1 with a convex surface facing the object side and a concave surface facing the image plane IA side and having negative refractive power; a second lens L2 with a convex surface facing the object side and a convex surface facing the image plane IA side and having positive refractive power; an aperture STO; a third lens L3 with a convex surface facing the object side and a convex surface facing the image plane IA side and having positive refractive power; and a fourth lens L4 with a concave surface facing the object side and a convex surface facing the image plane IA side and having negative refractive power.

[0225] Table 25 shows lens data of the imaging lens 110 of Example 7.

[0226] [Table 25]

[0227] Face number R D Nd vd 1 15.4065 0.3000 1.54449 56.33 2 0.8447 0.2752 3 2.3829 0.7205 1.64975 21.45 4 12.8603 0.2204 5(STO) INF 0.0986 6 3.0665 0.6189 1.56000 45.00 7 -0.2652 0.0600 8 -0.3969 0.8014 1.60792 26.90 9 -3.5637 0.0600 10 INF 0.4450 11 INF 0.2000

[0228] Table 26 and Table 27 below show aspherical surface data of the imaging lens 110 of Example 7. That is, Table 26 and Table 27 show the cone constant K and the aspherical coefficient Am of the lens system 17 .

[0229] [Table 26]

[0230] Face number K A4 A6 A8 1 3.09385E+01 8.89213E-01 -2.00856E+00 2.00430E+00 2 -4.63560E-01 2.60784E+00 -2.59820E+00 -2.09410E+01 3 9.72616E00 1.25079E00 4.85093E00 1.90468E01 4 2.00000E+01 8.02859E-01 2.44650E+00 -2.92520E+01 6 1.52781E+01 -9.68706E-01 6.57722E+00 -8.75613E+01 7 -3.03886E+00 -3.24487E+00 5.81366E+01 -7.42369E+02 8 -9.13346E-01 1.10543E+01 -8.50130E+01 3.95394E+02 9 5.42684E+00 1.02241E-01 3.31473E+00 -1.56431E+01

[0231] [Table 27]

[0232] Face number A10 A12 A14 A16 1 1.07694E+00 3.04165E+01 3.54300E+02 0.00000E+00 2 5.82158E+01 -5.82227E+01 2.09959E+01 0.00000E+00 3 -4.71175E+01 5.97044E+01 -2.89808E+01 0.00000E+00 4 1.97912E+02 -4.42533E+02 0.00000E+00 0.00000E+00 6 3.85561E+02 0.00000E+00 0.00000E+00 0.00000E+00 7 4.72943E+03 -1.57556E+04 2.43329E+04 -1.06526E+04 8 1.14238E+03 1.84519Ev03 1.21817E+03 0.00000E+00 9 3.27744E+01 3.73618E+01 2.24760E+01 5.58212E+00

[0233] Table 28 below shows the specification data of the lens system of Example 7. That is, Table 28 shows the focal length f, F number Fno, half angle of view ω, maximum image height ImgH, and total optical length TTL of the lens system 17 .

[0234] [Table 28]

[0235] f 0.85 Fno 2.60 ω 58.27 Ih 1.15 TTL 3.80

[0236] [Summary of Embodiments]

[0237] Table 29 shows the corresponding values ​​of conditional expressions (1) to (10) in the lens systems 11 to 17 of the above-mentioned Examples 1 to 7. In addition, Tables 30 and 31 show the parameters related to conditional expressions (1) to (10). As shown in Table 29, all the Examples satisfy all conditional expressions (1) to (10).

[0238] [Table 29]

[0239] [Table 30]

[0240] f f1 f2 f3 f4 TTL Imgl1 Example 1 0.848 1.26 2.39 0.59 1.17 3.100 1.184 Example 2 0.842 -1.19 1.87 0.59 -0.98 3.300 1.184 Example 3 0.759 -1.14 1.86 0.60 -1.06 3.600 1.238 Example 4 0.845 -1.06 1.88 0.56 -1.05 3.500 1.184 Example 5 0.750 -1.00 1.51 0.57 -0.99 3.600 1.170 Example 6 1.107 -1.68 3.03 0.74 -1.37 4.589 1.538 Example 7 0.848 1.65 3.15 0.47 0.81 3.800 1.150

[0241] [Table 31]

[0242] vd1 vd2 vd3 vd4 D12 EPD fir Example 1 56.33 20.40 56.33 20.40 0.321 0.353 0.852 Example 2 56.33 38.00 56.33 20.40 0.358 0.351 0.844 Example 3 56.33 28.00 56.33 20.40 0.530 0.345 0.762 Example 4 53.80 23.70 53.80 23.70 0.296 0.352 0.851 Example 5 56.33 20.40 56.33 20.40 0.498 0.300 0.753 Example 6 56.33 20.40 56.33 20.40 0.444 0.461 1.117 Example 7 56.33 21.45 45.00 26.90 0.275 0.326 0.861

[0243] In addition, as shown in the aberration diagrams of each embodiment ( Figure 3 , 6 , 9, 12, 15, 18, 21), the lens systems 11 to 17 are realized to ensure the amount of transmitted light and to correct aberration well despite having a wide field of view of about 60 degrees at half field of view. In addition, as shown in the coordinate diagram of the peripheral light amount relative to the image height of the imaging lens of each embodiment ( Figure 4 , 7 , 10, 13, 16, 19, 22), despite having a wide field of view, it is still possible to ensure that the amount of light at a position with a higher image height (peripheral light) is close to 50% of the amount of light at the optical axis position.

[0244] The embodiments of the present disclosure are described above, but the various configurations and combinations thereof in the various embodiments are only examples, and additions, omissions, substitutions, and other changes may be appropriately made without departing from the scope of the present disclosure. The present disclosure is not limited to the embodiments, but only to the claims.

[0245] Furthermore, each aspect disclosed in this specification may be combined with any other features disclosed in this specification.

[0246] The present disclosure described above includes the following [Item 1] to [Item 6].

[0247] [Item 1] An imaging lens having a lens system, wherein the lens system is configured in order from an object side to an image plane side:

[0248] a first lens having a concave surface facing the image plane and having a negative refractive power,

[0249] The second lens has positive refractive power,

[0250] Aperture

[0251] a third lens having a convex surface facing the image plane and having a positive refractive power, and

[0252] a fourth lens having a concave surface facing the object side and having a negative refractive power,

[0253] When the focal length of the lens system under the d-line is set to f, the focal length of the first lens is set to f1, the focal length of the fourth lens is set to f4, the Abbe numbers of the first to fourth lenses are set to νd1 to νd4, the total length of the lens system is set to TTL, and the maximum image height is set to ImgH, the lens system satisfies the following conditional equations (1) to (6).

[0254] -2<f1 / f<-0.9···(1)

[0255] -2.5<f4 / f<-0.7···(2)

[0256] νd1>40···(3)

[0257] νd1 / νd2>1.2···(4)

[0258] νd3 / νd4>1.4···(5)

[0259] 2<TTL / ImgH<4···(6)

[0260] [Item 2] The imaging lens according to Item 1, wherein:

[0261] When the distance between the concave surface of the first lens and the object-side surface of the second lens is set to D12, the lens system satisfies the following conditional expression (7).

[0262] D12 / f<0.8···(7)

[0263] [Item 3] The imaging lens according to Item 1 or 2, wherein:

[0264] When the entrance pupil diameter of the lens system is defined as EPD, the lens system satisfies the following conditional expression (8).

[0265] f / EPD<2.8···(8)

[0266] [Item 4] The imaging lens according to any one of Items 1 to 3, wherein:

[0267] When the focal length of the second lens is set to f2, the lens system satisfies the following conditional expression (9).

[0268] 1<f2 / f<4···(9)

[0269] [Item 5] The imaging lens according to any one of Items 1 to 4, wherein:

[0270] When the focal length of the lens system at a wavelength of 940 nm is defined as fir, the lens system satisfies the following conditional expression (10).

[0271] 0.92<fir / f<1.08···(10)

[0272] [Item 6] An imaging device including the imaging lens according to any one of Items 1 to 5.

Claims

1. A camera lens having a lens system, wherein the lens system is configured in order from the object side to the image side: a first lens having a concave surface facing the image plane and having a negative refractive power, The second lens has positive refractive power, Aperture a third lens having a convex surface facing the image plane and having a positive refractive power, and a fourth lens having a concave surface facing the object side and having a negative refractive power, When the focal length of the lens system under the d-line is set to f, the focal length of the first lens is set to f1, the focal length of the fourth lens is set to f4, the Abbe numbers of the first to fourth lenses are set to νd1 to νd4, the total length of the lens system is set to TTL, and the maximum image height is set to ImgH, the lens system satisfies the following conditional expressions (1) to (6): -2<f1 / f<-0.9···(1) -2.5<f4 / f<-0.7···(2) νd1>40···(3) νd1 / νd2>1.2···(4) νd3 / νd4>1.4···(5) 2<TTL / ImgH<4···(6).

2. The imaging lens according to claim 1, wherein: When the distance between the concave surface of the first lens and the object-side surface of the second lens is set to D12, the lens system satisfies the following conditional expression (7): D12 / f<0.8···(7).

3. The imaging lens according to claim 1, wherein: When the entrance pupil diameter of the lens system is set to EPD, the lens system satisfies the following conditional formula (8): f / EPD<2.8···(8).

4. The imaging lens according to claim 1, wherein: When the focal length of the second lens is set to f2, the lens system satisfies the following conditional expression (9): 1<f2 / f<4···(9).

5. The imaging lens according to claim 1, wherein: When the focal length of the lens system at a wavelength of 940 nm is set to fir, the lens system satisfies the following conditional formula (10): 0.92<fir / f<1.08···(10). 6 . An imaging device comprising the imaging lens according to claim 1 .

Images