Imaging lens and imaging device

Abstract

This imaging lens (10) is provided with, in order from the object side, a first lens (110) having a negative refractive power, a second lens (120) having a negative refractive power, a third lens (130) having a positive refractive power, an aperture stop (170), a fourth lens (140) having a positive refractive power, a fifth lens (150) having a negative refractive power, and a sixth lens (160) having a positive refractive power. Conditional expressions are satisfied: 0.6 < (R1 + R2) / (R1-R2) < 0.8 (1) and-1.1 < (dN4 / dT + dN6 / dT) / f <-0.7 (2).

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the priority of each of Japanese Patent Application No. 2022-136280 filed in Japan on August 29, 2022, Japanese Patent Application No. 2022-136287 filed in Japan on August 29, 2022, Japanese Patent Application No. 2022-136291 filed in Japan on August 29, 2022, Japanese Patent Application No. 2022-136294 filed in Japan on August 29, 2022, and Japanese Patent Application No. 2022-136302 filed in Japan on August 29, 2022, and the entire disclosed contents of these applications are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to a photographing lens and a photographing device. Background Art

[0004] The imaging lens used in cameras including surveillance cameras and vehicle-mounted cameras is required to be resistant to environmental changes and have good imaging performance in the entire area of ​​the screen. In addition, since the mounting space for mounting the imaging lens on the camera is often limited, the imaging lens is also required to be small and lightweight.

[0005] As a single-focus photographic lens that can meet the above requirements, the technologies described in Patent Documents 1 and 2 have been proposed. For example, Patent Document 1 discloses a lens unit that can be used well even in a harsh environment with a wide required temperature range and has high chromatic aberration correction accuracy. For example, Patent Document 2 discloses a lens unit that can be used in a wide temperature range and wavelength band and has excellent compactness.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Publication No. 2008-008960

[0009] Patent Document 2: Japanese Patent Application Publication No. 2013-047753 Summary of the invention

[0010] An imaging lens according to an embodiment of the present disclosure includes:

[0011] The invention comprises, in order from the object side, a first lens having negative refractive power, a second lens having negative refractive power, a third lens having positive refractive power, an aperture stop, a fourth lens having positive refractive power, a fifth lens having negative refractive power, and a sixth lens having positive refractive power.

[0012] When the curvature radius of the object side surface of the first lens is set to R1, the curvature radius of the image side surface of the first lens is set to R2, the refractive index temperature coefficient of the fourth lens in the temperature range of 20°C to 40°C with respect to the d-line is set to dN4 / dT, the refractive index temperature coefficient of the sixth lens in the temperature range of 20°C to 40°C with respect to the d-line is set to dN6 / dT, and the focal length of the photographing lens with respect to the d-line is set to f, the following conditional expression is satisfied:

[0013] 0.6<(R1+R2) / (R1-R2)<0.8 (1)

[0014] -1.1<(dN4 / dT+dN6 / dT) / f<-0.7 (2).

[0015] An imaging device according to an embodiment of the present disclosure includes:

[0016] an imaging lens including, in order from the object side, a first lens having negative refractive power, a second lens having negative refractive power, a third lens having positive refractive power, an aperture stop, a fourth lens having positive refractive power, a fifth lens having negative refractive power, and a sixth lens having positive refractive power; and

[0017] The imaging element converts the optical image formed by the imaging lens into an electrical signal.

[0018] When the curvature radius of the object side surface of the first lens is set to R1, the curvature radius of the image side surface of the first lens is set to R2, the refractive index temperature coefficient of the fourth lens in the temperature range of 20°C to 40°C with respect to the d-line is set to dN4 / dT, the refractive index temperature coefficient of the sixth lens in the temperature range of 20°C to 40°C with respect to the d-line is set to dN6 / dT, and the focal length of the photographing lens with respect to the d-line is set to f, the following conditional expression is satisfied:

[0019] 0.6<(R1+R2) / (R1-R2)<0.8 (43)

[0020] -1.1<(dN4 / dT+dN6 / dT) / f<-0.7 (44).

[0021] An imaging device according to an embodiment of the present disclosure includes:

[0022] an imaging lens including, in order from the object side, a first lens having negative refractive power, a second lens having negative refractive power, a third lens having positive refractive power, an aperture stop, a fourth lens having positive refractive power, a fifth lens having negative refractive power, and a sixth lens having positive refractive power; and

[0023] The imaging element converts the optical image formed by the imaging lens into an electrical signal.

[0024] When the axial distance from the image side surface of the second lens to the object side surface of the third lens is set to D4, the focal length of the photographing lens with respect to the d-line is set to f, and the axial thickness of the second lens is set to D3, the following conditional expression is satisfied:

[0025] D4 / f<0.08 (45)

[0026] 0.12<D3 / f<0.23 (46).

[0027] An imaging device according to an embodiment of the present disclosure includes:

[0028] an imaging lens including, in order from the object side, a first lens having negative refractive power, a second lens having negative refractive power, a third lens having positive refractive power, an aperture stop, a fourth lens having positive refractive power, a fifth lens having negative refractive power, and a sixth lens having positive refractive power; and

[0029] The imaging element converts the optical image formed by the imaging lens into an electrical signal.

[0030] When the curvature radius of the object side surface of the second lens is set to R3, the focal length of the photographing lens relative to the d-line is f, the curvature radius of the object side surface of the third lens is set to R5, and the curvature radius of the image side surface of the third lens is set to R6, the following conditional formula is satisfied:

[0031] -2.2<R3 / f<-1.2 (47)

[0032] -0.15<(R5+R6) / (R5-R6)<0.15 (48).

[0033] An imaging device according to an embodiment of the present disclosure includes:

[0034] an imaging lens including, in order from the object side, a first lens having negative refractive power, a second lens having negative refractive power, a third lens having positive refractive power, an aperture stop, a fourth lens having positive refractive power, a fifth lens having negative refractive power, and a sixth lens having positive refractive power; and

[0035] The imaging element converts the optical image formed by the imaging lens into an electrical signal.

[0036] When the combined focal length of the fourth lens, the fifth lens and the sixth lens with respect to the d-line is set to fg, the focal length of the photographing lens with respect to the d-line is set to f, and the refractive index of the fifth lens is set to N5, the following conditional expression is satisfied:

[0037] 1.4<fg / f<1.8 (49)

[0038] 0.35<N5 / f (50).

[0039] An imaging device according to an embodiment of the present disclosure includes:

[0040] an imaging lens including, in order from the object side, a first lens having negative refractive power, a second lens having negative refractive power, a third lens having positive refractive power, an aperture stop, a fourth lens having positive refractive power, a fifth lens having negative refractive power, and a sixth lens having positive refractive power; and

[0041] The imaging element converts the optical image formed by the imaging lens into an electrical signal.

[0042] When the curvature radius of the object side surface of the sixth lens is set to R11, the curvature radius of the image side surface of the sixth lens is set to R12, the Abbe number of the fourth lens is set to ν4, and the focal length of the photographing lens with respect to the d-line is set to f, the following conditional expression is satisfied:

[0043] 0.05<(R11+R12) / (R11-R12)<0.7 (51)

[0044] 12<ν4 / f (52)

[0045] The two surfaces of the second lens are respectively concave surfaces. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 2 is a lens configuration diagram of the imaging lens according to Example 1 of the present disclosure.

[0047] Figure 2A Yes means Figure 1 A graph showing the astigmatism of a photographing lens.

[0048] Figure 2B Yes means Figure 1 A graph showing the distortion of the shooting lens.

[0049] Figure 3 2 is a lens structure diagram of a photographing lens according to Example 2 of the present disclosure.

[0050] Figure 4A Yes means Figure 3 A graph showing the astigmatism of a photographing lens.

[0051] Figure 4B Yes means Figure 3 A graph showing the distortion of the shooting lens.

[0052] Figure 5It is a lens configuration diagram of an imaging lens according to Example 3 of the present disclosure.

[0053] Fig. 6A Yes means Figure 5 A graph showing the astigmatism of a photographing lens.

[0054] Figure 6B Yes means Figure 5 A graph showing the distortion of the shooting lens.

[0055] Figure 7 It is a lens configuration diagram of an imaging lens according to Example 4 of the present disclosure.

[0056] Fig. 8A Yes means Figure 7 A graph showing the astigmatism of a photographing lens.

[0057] Figure 8B Yes means Figure 7 A graph showing the distortion of the shooting lens.

[0058] Fig. 9 It is a lens configuration diagram of an imaging lens according to Example 5 of the present disclosure.

[0059] Fig. 10A Yes means Fig. 9 A graph showing the astigmatism of a photographing lens.

[0060] Fig. 10B Yes means Fig. 9 A graph showing the distortion of the shooting lens.

[0061] Fig.11 It is a lens structure diagram of the imaging lens involved in Example 6 of the present disclosure.

[0062] Fig. 12A Yes means Fig.11 A graph showing the astigmatism of a photographing lens.

[0063] Fig. 12B Yes means Fig.11 A graph showing the distortion of the shooting lens.

[0064] Fig.13 It is a lens configuration diagram of an imaging lens according to Example 7 of the present disclosure.

[0065] Fig.14A Yes means Fig.13 A graph showing the astigmatism of a photographing lens.

[0066] Fig. 14B Yes means Fig.13 A graph showing the distortion of the shooting lens.

[0067] Fig.15It is a lens configuration diagram of an imaging lens according to Example 8 of the present disclosure.

[0068] Fig.16A Yes means Fig.15 A graph showing the astigmatism of a photographing lens.

[0069] Fig. 16B Yes means Fig.15 A graph showing the distortion of the shooting lens.

[0070] Fig.17 It is a lens structure diagram of the imaging lens involved in Example 9 of the present disclosure.

[0071] Fig.18A Yes means Fig.17 A graph showing the astigmatism of a photographing lens.

[0072] Fig.18B Yes means Fig.17 A graph showing the distortion of the shooting lens. DETAILED DESCRIPTION

[0073] For example, in addition to the traditional visual recognition use, in-vehicle cameras are also used for sensing purposes to detect objects, and further performance is required. With the high pixel count of solid-state imaging elements such as CCD (Charge Coupled Device) and CMOS (Complementary Metal-Oxide Semiconductor Device), the imaging lens used in the camera is also required to have corresponding good optical performance.

[0074] According to one embodiment of the present disclosure, it is possible to provide an imaging lens and an imaging device that have a six-lens structure, are small, lightweight, and inexpensive, and have high optical performance by appropriately setting the shape of the lens.

[0075] Hereinafter, the shooting lens 10 and the shooting device 1 involved in one embodiment of the present disclosure will be described in detail with reference to the accompanying drawings. More specifically, the structure and function of the shooting lens 10 and the shooting device 1 common to each embodiment described later will be described. In each of the drawings showing the structure of the shooting lens 10 and the shooting device 1, the "object side" corresponds to the left side, and the "image side" corresponds to the right side. The drawings used in the following description are schematic drawings, and the dimensional ratios on the drawings may not necessarily be consistent with the actual ones.

[0076] Referring to the following description showing the structure of the imaging lens 10 and the imaging device 1 of Example 1 Figure 1 , the lens structure of the imaging lens 10 and the imaging device 1 according to one embodiment will be mainly described.

[0077] The imaging device 1 includes an imaging lens 10 and an imaging element 20 that converts an optical image formed by the imaging lens 10 into an electrical signal. The imaging element 20 includes, for example, a solid imaging element such as a CCD and a CMOS. An image plane 21 is formed on the surface of the imaging element 20. The imaging device 1 images the subject by imaging the image of the object as the subject on the image plane 21 of the imaging element 20 through the imaging lens 10.

[0078] The photographing lens 10 includes a first lens 110, a second lens 120, a third lens 130, an aperture stop 170, a fourth lens 140, a fifth lens 150, a sixth lens 160, a first flat plate 180a, and a second flat plate 180b, which are arranged in order from the object side. The fourth lens 140 and the fifth lens 150 are formed as a cemented lens. The photographing lens 10 is a six-lens structure single-focus photographing lens. The first lens 110, the second lens 120, the third lens 130, the fourth lens 140, the fifth lens 150, and the sixth lens 160 are respectively formed of glass materials.

[0079] The first lens 110 has a spherical shape. Both surfaces of the first lens 110 are concave surfaces. The second lens 120 has a spherical shape. Both surfaces of the second lens 120 are concave surfaces. The third lens 130 has a spherical shape. Both surfaces of the third lens 130 are convex surfaces. The fourth lens 140 has a spherical shape. Both surfaces of the fourth lens 140 are convex surfaces. The fifth lens 150 has a spherical shape. Both surfaces of the fifth lens 150 are concave surfaces. Both surfaces of the sixth lens 160 are aspherical surfaces. The first flat plate 180a includes optical components such as an IR (Infrared) cut filter. The second flat plate 180b includes optical components such as LID glass configured relative to the imaging element 20. The LID glass is a cover glass for the imaging element 20 as an image sensor.

[0080] The photographing lens 10 is substantially composed of a first lens 110, a second lens 120, a third lens 130, a fourth lens 140, a fifth lens 150, and a sixth lens 160. In the present disclosure, “substantially composed” means that the optical elements substantially constituting the photographing lens 10 are six lenses, namely, the first lens 110 to the sixth lens 160. However, in addition to these, the photographing lens 10 may also include a lens that substantially has no refractive power, and other optical elements other than the lens including the aperture and the cover glass. For example, the photographing lens 10 has an aperture aperture 170, and a first plate 180a and a second plate 180b in addition to the first lens 110 to the sixth lens 160.

[0081] The shooting lens 10 includes, from the object side, a first lens 110 with negative refractive power, a second lens 120 with negative refractive power, a third lens 130 with positive refractive power, an aperture stop 170, a fourth lens 140 with positive refractive power, a fifth lens 150 with negative refractive power, and a sixth lens 160 with positive refractive power.

[0082] In the wide-angle shooting lens 10, the focal length needs to be shortened in order to obtain a wide viewing angle, but due to the mechanical constraints of the shooting lens 10, the back focus must be longer than the focal length. Therefore, a lens with negative refractive power is arranged in front of the shooting lens 10 to temporarily diverge the light incident on the shooting lens 10 from the object side, and then the light is focused by the lens with positive refractive power at the rear. In this way, the principal point of the lens system can appear behind the shooting lens 10, thereby ensuring a back focus longer than the focal length.

[0083] More specifically, light is diverged by the first lens 110 and the second lens 120 having negative refractive power, and light is focused by the third lens 130, the fourth lens 140, and the sixth lens 160 having positive refractive power. In the photographing lens 10, by configuring the first lens 110 and the second lens 120 as negative lenses closest to the object side, a negative refractive power sufficient to place the principal point backward can be obtained. By configuring the third lens 130 having positive refractive power before the aperture stop 170, lateral chromatic aberration can be well corrected. By configuring the fourth lens 140 and the sixth lens 160 having positive refractive power after the aperture stop 170, the incident angle of light to the image plane 21 can be reduced, and aberrations can be well corrected.

[0084] The aperture stop 170 is disposed between the third lens 130 and the fourth lens 140. If the aperture stop 170 is disposed on the image side relative to the fourth lens 140, the photographing lens 10 will be large-scaled, which is not preferred. In addition, if the aperture stop 170 is disposed on the object side relative to the third lens 130, it is difficult to widen the angle of the photographing lens 10, which is not preferred. Therefore, by disposing the aperture stop 170 between the third lens 130 and the fourth lens 140, the photographing lens 10 can achieve good correction of various aberrations and compactness of the lens system.

[0085] The functions of the imaging lens 10 and the imaging device 1 according to one embodiment will be mainly described.

[0086] The imaging lens 10 satisfies the following conditional expressions (1) and (2).

[0087] 0.6<(R1+R2) / (R1-R2)<0.8 (1)

[0088] -1.1<(dN4 / dT+dN6 / dT) / f<-0.7 (2)

[0089] Wherein, R1 is the curvature radius of the object side surface of the first lens 110. R2 is the curvature radius of the image side surface of the first lens 110. dN4 / dT is the refractive index temperature coefficient of the fourth lens 140 with respect to the d-line (wavelength λ=587.56nm) in the temperature range of 20°C to 40°C. dN6 / dT is the refractive index temperature coefficient of the sixth lens 160 with respect to the d-line in the temperature range of 20°C to 40°C. f is the focal length of the photographing lens 10 with respect to the d-line.

[0090] Conditional equation (1) establishes a correlation between the respective curvature radii of the two surfaces of the first lens 110. When the value of (R1+R2) / (R1-R2) is greater than the upper limit of 0.8, the difference in curvature radii between the two concave surfaces of the first lens 110 becomes too large, making it difficult to correct astigmatism. When the value of (R1+R2) / (R1-R2) is less than the lower limit of 0.6, since the curvature radii of the two concave surfaces of the first lens 110 are too close to each other, a large image curvature will be generated. By satisfying conditional equation (1), correction of astigmatism becomes easy and the generation of image curvature is suppressed.

[0091] Conditional expression (2) associates the temperature coefficient of the refractive index of the fourth lens 140 and the temperature coefficient of the refractive index of the sixth lens 160 with the focal length of the photographing lens 10. When the value of (dN4 / dT+dN6 / dT) / f is greater than the upper limit value -0.7, the temperature coefficient of the refractive index of the convex lens including the fourth lens 140 and the sixth lens 160 is too high, and it is difficult to reduce the focus shift when the temperature changes. When the value of (dN4 / dT+dN6 / dT) / f is less than the lower limit value -1.1, the temperature coefficient of the refractive index of the convex lens including the fourth lens 140 and the sixth lens 160 is too low, and the focus shift caused by the concave lens included in the photographing lens 10, which should be offset, becomes overcorrection, and it is difficult to reduce the focus shift. By satisfying conditional expression (2), it is easy to reduce the focus shift when the temperature changes.

[0092] The imaging lens 10 may further satisfy the following conditional expression (3).

[0093] 0.14<D1 / f (3)

[0094] Wherein, D1 is the axial thickness of the first lens 110. That is, D1 is Figure 1 The distance from the object-side surface of the first lens 110 to the image-side surface of the first lens 110 on the optical axis Ax of the photographing lens 10 shown.

[0095] Conditional expression (3) relates the axial thickness of the first lens 110 to the focal length of the shooting lens 10. When the value of D1 / f is below the lower limit of 0.14, the axial thickness of the first lens 110 is too thin, so the refractive power of the first lens 110 as a biconcave lens is reduced, and correction of astigmatism becomes difficult. In addition, due to the thin axial thickness, processing of the first lens 110 becomes difficult. Moreover, due to the pressure applied from the holder for holding the first lens 110, the first lens 110 may also break. By satisfying conditional expression (3), correction of astigmatism and processing of the first lens 110 become easy, and damage to the first lens 110 caused by the holder, etc. can also be suppressed.

[0096] The imaging lens 10 may further satisfy the following conditional expression (4).

[0097] -3.8<f2 / f<-2 (4)

[0098] Wherein, f2 is the focal length of the second lens 120 relative to the d-line.

[0099] Conditional expression (4) relates the focal length of the second lens 120 to the focal length of the photographing lens 10. By making the value of f2 / f less than the upper limit value -2, the refractive power of the second lens 120 as a concave lens can be appropriately suppressed, and the correction of astigmatism becomes good. When the value of f2 / f is less than the lower limit value -3.8, the axial chromatic aberration generated in the second lens 120 is weakened, and as a result, the correction of the axial chromatic aberration of the entire photographing lens 10 becomes difficult. By satisfying conditional expression (4), the axial chromatic aberration of the entire photographing lens 10 is easily corrected.

[0100] In the imaging lens 10, by making both surfaces of the second lens 120 concave, it is possible to easily form a flat receiving portion that can contact the first lens 110 and the spacer in a flat surface without performing additional processing on the second lens 120. Thus, a structure with low tolerance sensitivity can be achieved. Figure 1 As shown, the flat receiving portion is formed on the second lens 120 in a region farthest from the optical axis Ax and in a region where the first lens 110 and the second lens 120 contact each other.

[0101] For example, when the lens surface is convex, it is necessary to additionally form a flat receiving portion in the area farthest from the optical axis on the periphery of the lens. In the case where there is no such flat receiving portion on the convex lens, the receiving position of the convex lens relative to the concave lens is unstable, and the optical axis of the convex lens is offset. As a result, when the convex lens is assembled in the lens system, it is also possible to exceed the assembly tolerance. Since it is not easy to additionally form a flat receiving portion on the periphery of a convex lens surface, it is preferred that a flat receiving portion be formed on the second lens 120 having a concave lens surface formed by normal processing.

[0102] The imaging lens 10 may further satisfy the following conditional expression (5).

[0103] 0.36<D2 / f<0.6 (5)

[0104] Wherein, D2 is the axial distance from the image side surface of the first lens 110 to the object side surface of the second lens 120. That is, D2 is Figure 1 The distance from the image side surface of the first lens 110 to the object side surface of the second lens 120 on the optical axis Ax of the taking lens 10 shown.

[0105] Conditional expression (5) relates the on-axis distance between the first lens 110 and the second lens 120 to the focal length of the photographing lens 10. By making the value of D2 / f less than the upper limit of 0.6, the optical path difference between the position on the optical axis Ax and the position away from the optical axis Ax in the air lens between the first lens 110 and the second lens 120 is suppressed. Thus, the generation of lateral chromatic aberration is suppressed. When the value of D2 / f is less than the lower limit of 0.36, the interval between the first lens 110 and the second lens 120 becomes significantly shorter, so it becomes difficult to correct the spherical aberration. By satisfying conditional expression (5), it becomes easy to correct the spherical aberration.

[0106] The imaging lens 10 may further satisfy the following conditional expression (6).

[0107] -6.7<R1 / f<-4.4 (6)

[0108] Conditional formula (6) relates the radius of curvature of the object side surface of the first lens 110 to the focal length of the shooting lens 10. When the value of R1 / f is above the upper limit value -4.4, correction becomes difficult due to the excessively long focal length outside the axis, and image curvature occurs. When the value of R1 / f is below the lower limit value -6.7, the refractive power outside the axis is too large, and thus overcorrection occurs, resulting in image curvature on the negative side. By satisfying conditional formula (6), the generation of image curvature is suppressed.

[0109] The imaging lens 10 may further satisfy the following conditional expression (7).

[0110] 4.7<ν3 / f<5.7 (7)

[0111] Here, ν3 is the Abbe number of the third lens 130 .

[0112] Conditional expression (7) relates the Abbe number of the third lens 130 to the focal length of the photographing lens 10. When the value of ν3 / f is greater than the upper limit of 5.7, the Abbe number of the third lens 130, which is a convex lens closer to the object side than the aperture stop 170, becomes larger, and lateral chromatic aberration is greatly generated. By satisfying conditional expression (7), the occurrence of lateral chromatic aberration is suppressed. By making the value of ν3 / f greater than the lower limit of 4.7, the axial chromatic aberration generated by the third lens, which is a convex lens, can be suppressed, and the axial chromatic aberration of the entire photographing lens 10 can be corrected.

[0113] The imaging lens 10 may further satisfy the following conditional expression (8).

[0114] N1 / f<0.34 (8)

[0115] Here, N1 is the refractive index of the first lens 110 .

[0116] Conditional formula (8) relates the refractive index of the first lens 110 to the focal length of the photographing lens 10. When the value of N1 / f is greater than the upper limit of 0.34, the refractive power of the first lens 110 becomes larger, for example, the refractive power at the intermediate image height becomes significant. As a result, a larger spherical aberration is generated. By satisfying conditional formula (8), the generation of spherical aberration is suppressed.

[0117] In the photographing lens 10, by making the object side surface of the first lens 110 a concave surface, it is possible to easily form a structure to be held by a holder or the like without performing additional processing on the first lens 110. In addition, when the light incident on the photographing lens 10 is reflected from the image plane 21 and is incident on the object side surface of the first lens 110, the re-reflected light tends to be diffused rather than focused. Therefore, it is possible to suppress the re-reflected light from being re-imaged on the image plane 21 and generating a ghost image.

[0118] The imaging lens 10 may further satisfy the following conditional expression (9).

[0119] Da / f<5.2 (9)

[0120] Here, Da is the total length of the photographing lens 10 on the optical axis Ax. Figure 1 The distance from the object side surface of the first lens 110 to the image plane 21 on the optical axis Ax of the taking lens 10 shown.

[0121] Conditional expression (9) relates the total length of the photographing lens 10 to the focal length of the photographing lens 10. By making the value of Da / f less than the upper limit of 5.2, the optical path ratio between the position on the optical axis Ax and the position away from the optical axis Ax in each air lens becomes higher, so astigmatism is suppressed. In addition, it contributes to the miniaturization of the photographing lens 10 in the total length direction and radial direction, and the design freedom of the camera frame is improved.

[0122] The imaging lens 10 may further satisfy the following conditional expression (10).

[0123] -1.5<f1 / f<-1.2 (10)

[0124] Wherein, f1 is the focal length of the first lens 110 relative to the d-line.

[0125] Conditional expression (10) relates the focal length of the first lens 110 to the focal length of the photographing lens 10. When the value of f1 / f is greater than the upper limit value -1.2, the refractive power of the first lens 110 as a concave lens in the photographing lens 10 becomes too large, and a large image curvature is generated. By satisfying conditional expression (10), the generation of image curvature is suppressed. By making the value of f1 / f greater than the lower limit value -1.5, the refractive power of the first lens 110 does not become too small, so that the axial chromatic aberration can be corrected well.

[0126] The imaging lens 10 may further satisfy the following conditional expression (11).

[0127] 1.6<f3 / f<3.1 (11)

[0128] Wherein, f3 is the focal length of the third lens 130 relative to the d-line.

[0129] Conditional expression (11) associates the focal length of the third lens 130 with the focal length of the shooting lens 10. When the value of f3 / f is greater than the upper limit of 3.1, the refractive power of the third lens 130, which is a convex lens closer to the front than the aperture stop 170, becomes smaller, and image curvature occurs. When the value of f3 / f is less than the lower limit of 1.6, the refractive power of the third lens 130, which is a convex lens in the shooting lens 10, becomes too large, and it is difficult to correct the axial chromatic aberration generated by the convex lens. By satisfying conditional expression (11), the generation of image curvature is suppressed, and it is easy to correct the axial chromatic aberration generated by the convex lens.

[0130] In the photographing lens 10, the fourth lens 140 and the fifth lens 150 are formed into a cemented lens, and the fourth lens 140 and the fifth lens 150 with high sensitivity to axis deviation can be formed into a cemented lens, so that an optical system with low tolerance sensitivity can be realized. In addition, the photographing lens 10 can reduce the number of components by cementing the lens, and reduce the workload of assembling the photographing lens 10.

[0131] In the imaging lens 10, both surfaces of the sixth lens 160 are aspherical, and the sixth lens 160 closest to the image plane 21 is aspherical, so that the incident angle of light to the imaging element 20 can be easily adjusted. As a result, spherical aberration and astigmatism can be easily corrected.

[0132] The imaging lens 10 may further satisfy the following conditional expression (12).

[0133] 1.45<f6 / f<1.8 (12)

[0134] Here, f6 is the focal length of the sixth lens 160 relative to the d-line.

[0135] Conditional formula (12) associates the focal length of the sixth lens 160 with the focal length of the shooting lens 10. When the value of f6 / f is greater than the upper limit of 1.8, the refractive power of the convex lens closest to the image plane 21, that is, the sixth lens 160, becomes smaller, and the image plane 21 tilts toward the object side, making it difficult to correct the image plane curvature. By satisfying conditional formula (12), the correction of the image plane curvature becomes easier. By making the value of f6 / f greater than the lower limit of 1.45, the refractive power of the sixth lens 160 will not become too large, and the tolerance sensitivity can be reduced. As a result, the image plane 21 will not tilt toward the image side, and the correction of the image plane curvature becomes easier.

[0136] In the photographing lens 10 , the first lens 110 , the second lens 120 , the third lens 130 , the fourth lens 140 , the fifth lens 150 , and the sixth lens 160 are respectively formed of glass materials, thereby suppressing yellowing caused by ultraviolet rays and changes in optical characteristics caused by temperature changes.

[0137] The imaging lens 10 may further satisfy the following conditional expression (13).

[0138] 48<W (13)

[0139] Here, W is the half viewing angle of the light incident on the image plane 21 at the maximum image height position.

[0140] Conditional expression (13) is related to the angle of view of the entire system of the photographing lens 10. When the value of W is less than the lower limit value 48, it is difficult to ensure the photographing range that the photographing device 1 used for, for example, a vehicle-mounted camera should satisfy. By satisfying conditional expression (13), it is easy to ensure the photographing range that the photographing device 1 used for, for example, a vehicle-mounted camera should satisfy.

[0141] The imaging lens 10 may further satisfy the following conditional expression (14).

[0142] -2.0<f5 / f<-1.1 (14)

[0143] Here, f5 is the focal length of the fifth lens 150 with respect to the d-line.

[0144] Conditional expression (14) relates the focal length of the fifth lens 150 to the focal length of the photographing lens 10. When the value of f5 / f is greater than the upper limit value -1.1, the refractive power of the fifth lens 150 becomes larger. Since the fifth lens 150 is a concave lens closer to the image side than the aperture stop 170, a larger lateral chromatic aberration is generated in the reverse direction. When the value of f5 / f is less than the lower limit value -2.0, the refractive power of the negative fifth lens 150 that cancels the axial chromatic aberration generated in the positive fourth lens 140 becomes smaller, and correction of axial chromatic aberration becomes difficult. By satisfying conditional expression (14), the generation of lateral chromatic aberration in the reverse direction is suppressed, and correction of axial chromatic aberration becomes easier.

[0145] The imaging lens 10 may further satisfy the following conditional expression (15).

[0146] 1.2<f4 / f<1.8 (15)

[0147] Wherein, f4 is the focal length of the fourth lens 140 with respect to the d-line.

[0148] Conditional expression (15) relates the focal length of the fourth lens 140 to the focal length of the photographing lens 10. When the value of f4 / f is greater than the upper limit of 1.8, the refractive power of the fourth lens 140 as a convex lens becomes smaller, the image plane 21 is tilted toward the image side, and correction of image curvature becomes difficult. When the value of f4 / f is less than the lower limit of 1.2, the refractive power of the positive fourth lens 140 becomes too large, and correction of axial chromatic aberration by the negative fifth lens 150 becomes difficult. By satisfying conditional expression (15), correction of image curvature becomes easy, and correction of axial chromatic aberration by the negative fifth lens 150 also becomes easy.

[0149] The photographing lens 10 may also satisfy the following conditional expressions (16) and (17).

[0150] D4 / f<0.08 (16)

[0151] 0.12<D3 / f<0.23 (17)

[0152] Wherein, D4 is the axial distance from the image side surface of the second lens 120 to the object side surface of the third lens 130. That is, D4 is Figure 1 The distance from the image side surface of the second lens 120 to the object side surface of the third lens 130 on the optical axis Ax of the photographing lens 10 shown in FIG. f is the focal length of the photographing lens 10 with respect to the d-line (wavelength λ=587.56nm). D3 is the axial thickness of the second lens 120. That is, D3 is Figure 1 The distance from the object-side surface of the second lens 120 to the image-side surface of the second lens 120 on the optical axis Ax of the photographing lens 10 shown.

[0153] Conditional expression (16) relates the axial distance between the second lens 120 and the third lens 130 to the focal length of the photographing lens 10. When the value of D4 / f is greater than the upper limit of 0.08, the interval between the negative lens group composed of the first lens 110 and the second lens 120 and the positive lens group composed of the third lens 130 to the sixth lens 160 becomes too wide. As a result, correction of axial chromatic aberration becomes difficult. By satisfying conditional expression (16), correction of axial chromatic aberration becomes easy.

[0154] Conditional expression (17) relates the axial thickness of the second lens 120 to the focal length of the photographing lens 10. When the value of D3 / f is less than the lower limit of 0.12, the refractive power of the second lens 120 as a concave lens becomes smaller, so image curvature occurs. When the value of D3 / f is greater than the upper limit of 0.23, the optical path length of the light passing through the second lens 120 becomes longer, so a larger axial chromatic aberration occurs. By satisfying conditional expression (17), the generation of image curvature and the generation of axial chromatic aberration are suppressed.

[0155] The imaging lens 10 may further satisfy the following conditional expression (18).

[0156] N2 / f<0.33 (18)

[0157] Wherein, N2 is the refractive index of the second lens 120 .

[0158] Conditional expression (18) relates the refractive index of the second lens 120 to the focal length of the photographing lens 10. When the value of N2 / f is equal to or greater than the upper limit of 0.33, the refractive power of the second lens 120 as a concave lens becomes too large, and the image plane 21 tilts toward the image side. By satisfying conditional expression (18), the tilt of the image plane 21 toward the image side is suppressed.

[0159] The imaging lens 10 may further satisfy the following conditional expression (19).

[0160] -1<(R3+R4) / (R3-R4)<-0.82 (19)

[0161] Wherein, R3 is the curvature radius of the object-side surface of the second lens 120 . Wherein, R4 is the curvature radius of the image-side surface of the second lens 120 .

[0162] Conditional expression (19) establishes a relationship between the curvature radii of the two surfaces of the second lens 120. When the value of (R3+R4) / (R3-R4) is less than the lower limit value -1, the difference in the absolute value of the curvature radii of the two concave surfaces of the second lens 120 becomes large, and astigmatism occurs. When the value of (R3+R4) / (R3-R4) is greater than the upper limit value -0.82, the difference in the absolute value of the curvature radii of the two concave surfaces of the second lens 120 becomes small, and correction of axial chromatic aberration becomes difficult. By satisfying conditional expression (19), correction of axial chromatic aberration becomes easy, and the generation of astigmatism is suppressed.

[0163] The imaging lens 10 may also satisfy the following conditional expression (20).

[0164] 0.77<R2 / f<0.9 (20)

[0165] Here, R2 is the radius of curvature of the image-side surface of the first lens 110 .

[0166] Conditional expression (20) establishes a relationship between the radius of curvature of the image side surface of the first lens 110 and the focal length of the shooting lens 10. When the value of R2 / f is greater than the upper limit of 0.9, focusing at the concave lens located closest to the object side, namely the first lens 110, becomes difficult, and spherical aberration will occur. When the value of R2 / f is less than the lower limit of 0.77, the first lens 110 becomes a shape that is difficult to manufacture. In addition, the refractive power of the first lens 110 as a concave lens becomes too large, and the image plane 21 will tilt toward the image side. By satisfying conditional expression (20), the generation of spherical aberration and the tilt of the image plane 21 toward the image side are suppressed.

[0167] The imaging lens 10 may further satisfy the following conditional expression (21).

[0168] 4.8<ν5 / f<5.5 (21)

[0169] Here, ν5 is the Abbe number of the fifth lens 150 .

[0170] Conditional expression (21) relates the Abbe number of the fifth lens 150 to the focal length of the photographing lens 10. When the value of ν5 / f is greater than the upper limit of 5.5, the axial chromatic aberration of the fifth lens 150 as a concave lens is reduced, and correction of the entire optical system becomes difficult. When the value of ν5 / f is less than the lower limit of 4.8, a larger axial chromatic aberration will be generated, resulting in overcorrection. By satisfying conditional expression (21), the axial chromatic aberration of the entire optical system can be corrected.

[0171] The imaging lens 10 may further satisfy the following conditional expression (22).

[0172] 1.4<fg / f<1.8 (22)

[0173] Here, fg is the combined focal length of the fourth lens 140 , the fifth lens 150 , and the sixth lens 160 with respect to the d-line.

[0174] Conditional expression (22) relates the composite focal length of the fourth lens 140 to the sixth lens 160 to the focal length of the photographing lens 10. When the value of fg / f is greater than the upper limit of 1.8, it becomes difficult to focus light by the fourth lens 140, the fifth lens 150, and the sixth lens 160 located on the image side of the aperture stop 170, and astigmatism occurs. When the value of fg / f is less than the lower limit of 1.4, it becomes easy to focus light, but since the refractive power of the lens group located on the image side of the aperture stop 170 is too large, the image plane 21 in the meridional direction will tilt toward the object side. By satisfying conditional expression (22), the generation of astigmatism and the tilt of the image plane 21 in the meridional direction toward the object side are suppressed.

[0175] The photographing lens 10 may also satisfy the following conditional expressions (23) and (24).

[0176] -2.2<R3 / f<-1.2 (23)

[0177] -0.15<(R5+R6) / (R5-R6)<0.15 (24)

[0178] Wherein, R3 is the curvature radius of the object side surface of the second lens 120. f is the focal length of the photographing lens 10 relative to the d-line. R5 is the curvature radius of the object side surface of the third lens 130. R6 is the curvature radius of the image side surface of the third lens 130.

[0179] Conditional formula (23) establishes a relationship between the radius of curvature of the object side surface of the second lens 120 and the focal length of the shooting lens 10. The object side surface of the second lens 120 has the function of further refracting the light focused by the first lens 110. When the value of R3 / f is above the upper limit value -1.2, the refractive power of the object side surface of the second lens 120 becomes too large, thereby generating a large astigmatism. When the value of R3 / f is below the lower limit value -2.2, the refractive power of the object side surface of the second lens 120 becomes too small, thereby generating a large image curvature. By satisfying conditional formula (23), the generation of astigmatism and the generation of image curvature are suppressed.

[0180] Conditional formula (24) establishes a correlation between the curvature radii of the two surfaces of the third lens 130. When the value of (R5+R6) / (R5-R6) is greater than the upper limit of 0.15, the curvature radius of the object side surface of the third lens 130 is greater than the curvature radius of the image side surface of the third lens 130, resulting in a larger image curvature. By satisfying conditional formula (24), the generation of image curvature is suppressed. By making the value of (R5+R6) / (R5-R6) greater than the lower limit of -0.15, the curvature radius of the image side surface of the third lens 130 is greater than the curvature radius of the object side surface of the third lens 130, and astigmatism can be corrected.

[0181] The imaging lens 10 may further satisfy the following conditional expression (25).

[0182] D5 / f<0.75 (25)

[0183] Wherein, D5 is the axial thickness of the third lens 130. That is, D5 is Figure 1 The distance from the object-side surface of the third lens 130 to the image-side surface of the third lens 130 on the optical axis Ax of the photographing lens 10 is shown.

[0184] Conditional expression (25) relates the axial thickness of the third lens 130 to the focal length of the photographing lens 10. When the value of D5 / f is equal to or greater than the upper limit of 0.75, the optical path length of light passing through the third lens 130, which is a convex lens disposed in front of the aperture stop 170, becomes longer, and lateral chromatic aberration is significantly generated. By satisfying conditional expression (25), the generation of lateral chromatic aberration is suppressed.

[0185] The imaging lens 10 may further satisfy the following conditional expression (26).

[0186] 0.03<D6 / f (26)

[0187] Wherein, D6 is the axial distance from the image side surface of the third lens 130 to the object side surface of the fourth lens 140. That is, D6 is Figure 1 The distance from the image side surface of the third lens 130 to the object side surface of the fourth lens 140 on the optical axis Ax of the photographing lens 10 is shown.

[0188] Conditional expression (26) relates the axial distance between the third lens 130 and the fourth lens 140 to the focal length of the photographing lens 10. When the value of D6 / f is equal to or less than the lower limit of 0.03, the lens group having negative refractive power on the object side of the aperture stop 170 and the lens group having positive refractive power on the image side of the aperture stop 170 are too close to each other, so that large axial chromatic aberration occurs. By satisfying conditional expression (26), the occurrence of axial chromatic aberration is suppressed.

[0189] The imaging lens 10 may further satisfy the following conditional expression (27).

[0190] 10<ν1 / f<15 (27)

[0191] Here, ν1 is the Abbe number of the first lens 110 .

[0192] Conditional expression (27) relates the Abbe number of the first lens 110 to the focal length of the photographing lens 10. When the value of ν1 / f is greater than the upper limit of 15, the influence of the negative lens in the entire optical system of the photographing lens 10 becomes too small, resulting in a large axial chromatic aberration. When the value of ν1 / f is less than the lower limit of 10, it becomes overcorrected and a large axial chromatic aberration is generated. By satisfying conditional expression (27), the generation of axial chromatic aberration is suppressed.

[0193] The imaging lens 10 may further satisfy the following conditional expression (28).

[0194] N4 / f<0.4 (28)

[0195] Here, N4 is the refractive index of the fourth lens 140 .

[0196] Conditional expression (28) relates the refractive index of the fourth lens 140 to the focal length of the photographing lens 10. When the value of N4 / f is greater than the upper limit of 0.4, the refractive index of the fourth lens 140 located behind the aperture stop 170 becomes too high, making it difficult to ensure the back focal length. In addition, image curvature is generated due to the high refractive index of the fourth lens 140 as a convex lens. By satisfying conditional expression (28), it is easy to ensure the back focal length and suppress the generation of image curvature.

[0197] The imaging lens 10 may further satisfy the following conditional expression (29).

[0198] 4.8<fg / f (29)

[0199] Here, fg is the combined focal length of the fourth lens 140 and the fifth lens 150 with respect to the d-line.

[0200] Conditional expression (29) relates the combined focal length of the fourth lens 140 and the fifth lens 150 to the focal length of the photographing lens 10. When the value of fg / f is equal to or less than the lower limit value of 4.8, the combined focal length of the fourth lens 140 as a convex lens and the fifth lens 150 as a concave lens located behind the aperture stop 170 becomes shorter, resulting in a large axial chromatic aberration. By satisfying conditional expression (29), the generation of axial chromatic aberration is suppressed.

[0201] The photographing lens 10 may also satisfy the following conditional expressions (30) and (31).

[0202] 1.4<fg / f<1.8 (30)

[0203] 0.35<N5 / f (31)

[0204] Wherein, fg is the combined focal length of the fourth lens 140 , the fifth lens 150 , and the sixth lens 160 with respect to the d-line, f is the focal length of the photographing lens 10 with respect to the d-line, and N5 is the refractive index of the fifth lens 150 .

[0205] Conditional expression (30) relates the composite focal length of the fourth lens 140 to the sixth lens 160 to the focal length of the photographing lens 10. When the value of fg / f is greater than the upper limit of 1.8, it becomes difficult to focus light by the fourth lens 140, the fifth lens 150, and the sixth lens 160 located on the image side of the aperture stop 170, and astigmatism occurs. When the value of fg / f is less than the lower limit of 1.4, it becomes easy to focus light, but since the refractive power of the lens group located on the image side of the aperture stop 170 is too large, the image plane 21 in the meridional direction is tilted toward the object side. By satisfying conditional expression (30), the generation of astigmatism and the tilt of the image plane 21 in the meridional direction toward the object side are suppressed.

[0206] Conditional expression (31) relates the refractive index of the fifth lens 150 to the focal length of the imaging lens 10. By making the value of N5 / f greater than the lower limit of 0.35, the refractive power of the fifth lens 150, which is a concave lens located behind the aperture stop 170, can be ensured, and axial chromatic aberration can be corrected.

[0207] The imaging lens 10 may further satisfy the following conditional expression (32).

[0208] -0.4<(R8+R9) / (R8-R9)<0.25 (32)

[0209] Wherein, R8 is the curvature radius of the object-side surface of the fourth lens 140 , and R9 is the curvature radius of the image-side surface of the fourth lens 140 .

[0210] Conditional expression (32) relates the curvature radius of each of the two surfaces of the fourth lens 140. When the value of (R8+R9) / (R8-R9) is greater than the upper limit of 0.25, the difference in curvature radius between the front and back of the convex lens disposed near the aperture stop 170, i.e., the fourth lens 140, becomes larger, resulting in greater astigmatism. By satisfying conditional expression (32), the generation of astigmatism is suppressed. By making the value of (R8+R9) / (R8-R9) greater than the lower limit of -0.4, correction of axial chromatic aberration can be easily performed.

[0211] The imaging lens 10 may further satisfy the following conditional expression (33).

[0212] 0.4<D8 / f<0.7 (33)

[0213] Wherein, D8 is the axial thickness of the fourth lens 140. That is, D8 is Figure 1The distance from the object-side surface of the fourth lens 140 to the image-side surface of the fourth lens 140 on the optical axis Ax of the photographing lens 10 is shown.

[0214] Conditional expression (33) relates the axial thickness of the fourth lens 140 to the focal length of the photographing lens 10. By making the value of D8 / f less than the upper limit of 0.7, after the light passes through the convex lens disposed near the aperture stop 170, that is, the fourth lens 140, the light in the sagittal direction and the meridional direction is appropriately refracted, thereby suppressing the generation of astigmatism. When the value of D8 / f is less than the lower limit of 0.4, the thickness of the fourth lens 140 becomes thinner, so that the image plane 21 in the meridional direction is curved. When conditional expression (33) is satisfied, the curvature of the image plane 21 in the meridional direction is suppressed.

[0215] The imaging lens 10 may further satisfy the following conditional expression (34).

[0216] 0.015<D10 / f (34)

[0217] Wherein, D10 is the axial distance from the image side surface of the fifth lens 150 to the object side surface of the sixth lens 160. That is, D10 is Figure 1 The distance from the image side surface of the fifth lens 150 to the object side surface of the sixth lens 160 on the optical axis Ax of the photographing lens 10 is shown.

[0218] Conditional expression (34) relates the axial distance between the fifth lens 150 and the sixth lens 160 to the focal length of the imaging lens 10. By setting the value of D10 / f to be greater than the lower limit of 0.015, the incident angle of light incident on the image plane 21 is suppressed.

[0219] The imaging lens 10 may further satisfy the following conditional expression (35).

[0220] R8 / f<1.9 (35)

[0221] Conditional expression (35) relates the radius of curvature of the object side surface of the fourth lens 140 to the focal length of the photographing lens 10. By making the value of R8 / f less than the upper limit of 1.9, the convex surface of the fourth lens 140 located further back than the aperture stop 170 is constrained, and the total optical length can be miniaturized. Therefore, the generation of astigmatism is suppressed.

[0222] The imaging lens 10 may further satisfy the following conditional expression (36).

[0223] 11<ν2 / f (36)

[0224] Here, ν2 is the Abbe number of the second lens 120.

[0225] Conditional expression (36) relates the Abbe number of the second lens 120 to the focal length of the imaging lens 10. By making the value of ν2 / f greater than the lower limit 11, it is easy to correct lateral chromatic aberration. In addition, it is easy to reduce the cost of the imaging lens 10 by selecting an inexpensive material.

[0226] The photographing lens 10 may also satisfy the following conditional expressions (37) and (38).

[0227] 0.05<(R11+R12) / (R11-R12)<0.7 (37)

[0228] 12<ν4 / f (38)

[0229] Here, R11 is the curvature radius of the object-side surface of the sixth lens 160. R12 is the curvature radius of the image-side surface of the sixth lens 160. ν4 is the Abbe number of the fourth lens 140. f is the focal length of the photographing lens 10 with respect to the d-line.

[0230] Conditional expression (37) establishes a relationship between the respective radii of curvature of the two surfaces of the sixth lens 160. By making the value of (R11+R12) / (R12-R12) less than the upper limit of 0.7, in the convex lens, i.e., the sixth lens 160, which is arranged at a position closest to the image plane 21, the difference in the absolute values ​​of the radii of curvature of the two surfaces will not become too large. Therefore, correction of astigmatism becomes easy. When the value of (R11+R12) / (R12-R12) is less than the lower limit of 0.05, the difference in the absolute difference becomes smaller, so that image curvature is generated in the light in the meridional direction. By satisfying conditional expression (37), the generation of image curvature is suppressed.

[0231] The conditional expression (38) relates the Abbe number of the fourth lens 140 to the focal length of the photographing lens 10. By making the value of ν4 / f greater than the lower limit of 12, the axial chromatic aberration generated in the fourth lens 140 can be corrected by the fifth lens 150. In addition, by satisfying the conditional expression (38), it becomes possible to select an inexpensive material, and it is easy to realize the low cost of the photographing lens 10.

[0232] The imaging lens 10 may further satisfy the following conditional expression (39).

[0233] 0.4<D11 / f<0.9 (39)

[0234] Wherein, D11 is the axial thickness of the sixth lens 160. That is, D11 is Figure 1 The distance from the object-side surface of the sixth lens 160 to the image-side surface of the sixth lens 160 on the optical axis Ax of the photographing lens 10 is shown.

[0235] Conditional expression (39) relates the axial thickness of the sixth lens 160 to the focal length of the photographing lens 10. By making the value of D11 / f less than the upper limit of 0.9, the sixth lens 160 does not become too thick, and lateral chromatic aberration can be corrected. In addition, by making the sixth lens 160 have an appropriate thickness, the sixth lens 160 has a shape that is easy to assemble in the photographing lens 10. By making the value of D11 / f greater than the lower limit of 0.4, the refractive power of the sixth lens 160 does not become too large, and the generation of field curvature is suppressed.

[0236] The imaging lens 10 may further satisfy the following conditional expression (40).

[0237] R12 / f<-1.2 (40)

[0238] Conditional expression (40) relates the curvature radius of the image side surface of the sixth lens 160 to the focal length of the photographing lens 10. By making the value of R12 / f less than the upper limit value -1.2, the refractive power of the image side surface of the sixth lens 160 does not become too large, and the tolerance sensitivity is reduced. In addition, astigmatism can be appropriately corrected.

[0239] The imaging lens 10 may further satisfy the following conditional expression (41).

[0240] N6 / f<0.4 (41)

[0241] Here, N6 is the refractive index of the sixth lens 160 .

[0242] Conditional formula (41) relates the refractive index of the sixth lens 160 to the focal length of the shooting lens 10. When the value of N6 / f is greater than the upper limit of 0.4, the refractive index of the convex lens located closest to the image plane 21, that is, the sixth lens 160, becomes higher, so it becomes difficult to correct lateral chromatic aberration. By satisfying conditional formula (41), it becomes easier to correct lateral chromatic aberration. In addition, the sixth lens 160 has an aspherical shape, and by setting an upper limit on the refractive index, the degree of freedom in the selection of the material of the sixth lens 160 becomes higher.

[0243] The imaging lens 10 may further satisfy the following conditional expression (42).

[0244] 1.7<Db / f (42)

[0245] Where Db is the back focal length. Figure 1 The distance from the image side surface of the sixth lens 160 to the image plane 21 on the optical axis Ax of the photographing lens 10 is shown.

[0246] Conditional expression (42) relates the back focus to the focal length of the photographing lens 10. When the value of Db / f is less than the lower limit of 1.7, it is difficult to arrange optical components such as an IR cut filter and LID glass in the photographing lens 10, and it is not easy to constitute an optical system. By satisfying conditional expression (42), it is easy to arrange optical components in the photographing lens 10, and it is easy to constitute an optical system.

[0247] (Example)

[0248] Next, the lens structure of the embodiment of the photographing lens 10 of the present disclosure is mainly described. More specifically, embodiments 1 to 9 based on specific numerical values ​​of the photographing lens 10 are shown. In embodiments 1 to 9, the positive and negative refractive power of each lens, the surface shape, and the parameters shown in conditional expressions (1) to (42) have the characteristics of the above-mentioned one embodiment.

[0249] In Examples 1 to 9, the focal length f of the above-mentioned photographing lens 10, the total length Da on the optical axis Ax of the photographing lens 10, the F value, and the image height are shown in the following Table 1. In each data of each Example in Table 1, the values ​​derived from the lens specifications including the focal length f are values ​​with respect to the d-line unless otherwise specified.

[0250] [Table 1]

[0251] Example 1 2 3 4 5 6 7 8 9 Focal distance f(mm) 4.765 4.774 4.767 4.773 4.767 4.797 4.797 4.784 4.824 F-number 1.560 1.560 1.560 1.560 1.560 1.560 1.560 1.560 1.560 Image height(mm) 3.645 3.645 3.645 3.645 3.645 3.645 3.645 3.645 3.645 Total length Da(mm) 23.985 23.981 24.000 24.000 24.000 24.000 24.000 24.000 24.874

[0252] In Examples 1 to 9, the values ​​of the parameters included in each of Conditional Expressions (1) to (42) are shown in Table 2 below.

[0253] [Table 2]

[0254] Conditional expression Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 (1) 0.69979757 0.687106998 0.656983935 0.6720398 0.668458008 0.682434524 0.67818359 0.677545932 0.766270198 (2) -0.756381973 -0.755065229 -0.755128582 -0.754179411 -0.755207787 -1.064340422 -1.064251581 -1.067146534 -1.059190031 (3) 0.147071273 0.146818239 0.146830558 0.146615997 0.146845959 0.14608594 0.146073746 0.146471093 0.145379024 (4) 2.30558462 2.195154159 2.244878131 2.242437047 2.245494766 3.265669387 3.264594228 2.981891988 3.617803323 (5) 0.382393109 0.381727421 0.504522408 0.579365238 0.549704158 0.3854696 0.382886378 0.392444025 0.498412368 (6) -4.732782715 -4.541730535 -4.247983687 -4.369306335 -4.350868156 -4.221516763 -4.187121115 -4.236354208 -6.479416407 (7) 5.348545015 5.339234028 5.339682007 5.33297021 5.340242086 4.999499134 4.999081822 5.012680212 4.975306334 (8) 0.329620548 0.32904673 0.329074338 0.328660703 0.329108855 0.313141474 0.313115336 0.317381515 0.315015161 (9) 5.039483274 5.029728224 5.034190544 5.027862739 5.03471858 5.008660809 5.008242733 5.021866042 5.166037541 (10) -1.23176174 -1.231626327 -1.267649872 -1.246882935 -1.255137721 -1.32163178 -1.328339112 -1.303818292 -1.449967186 (11) 1.847716357 1.794544654 1.781336578 1.636719739 1.695889782 2.611713379 2.548900899 2.384074198 3.001173624 (12) 1.754496691 1.73915978 1.5702601 1.503120836 1.563834987 1.661090219 1.572213435 1.560237283 1.548604361 (13) 49.53273073 49.43229698 19.92867021 49.91525567 49.93044434 49.95370564 49.96028202 49.9305478 48.4121484 (14) -1.395119025 -1.328379756 -1.24146453 -1.123669083 -1.193557658 -1.778965085 -1.706236306 -1.630378523 -1.93078027 (15) 1.239244669 1.21611477 1.303325712 1.289060209 1.286823512 1.445321911 1.506168903 1.476266661 1.75221433 (16) 0.02101061 0.020974034 0.020975794 0.020949428 0.020977994 0.02086942 0.020867678 0.020924442 0.072689512 (17) 0.168084883 0.157305256 0.157318455 0.146645997 0.146845959 0.17739007 0.208676781 0.188319977 0.20768432 (18) 0.329620548 0.32904673 0.329074338 0.328660703 0.329108855 0.316845796 0.316819349 0.328268712 0.325821184 (19) -0.842761618 -0.850061209 -0.877934272 -0.877934272 -0.877934272 -0.918465228 -0.918465228 -0.918465228 -0.980090913 (20) 0.835860043 0.842315102 0.879384899 0.857012244 0.864568055 0.796826244 0.802942117 0.814302381 0.857418484 (21) 5.348515015 5.339231028 5.339682007 5.33297021 5.340242086 4.963749817 4.96333549 4.976836643 4.93973001 (22) 1.593139861 1.616863472 1.662464863 1.724781066 1.690577461 1.472871257 1.494599697 1.510346489 1.547712984 (23) 1.434227566 1.359877745 1.363426606 1.361712825 1.363569615 1.773900703 1.773752635 1.778577556 2.088189595 (24) 0.008088577 0.120018152 0.082095522 -0.059131155 -0.015383706 -0.121003125 -0.092781799 -0.015907574 0 (25) 0.735371363 0.734091195 0.734152788 0.733229983 0.734229793 0.730429701 0.730368732 0.732355164 0.726895119 (26) 0.21783591 0.159165826 0.041951588 0.041898856 0.041955988 0.299539558 0.314526443 0.267994546 0.265996414 (27) 11.77520748 11.75470867 11.75569493 11.74091842 11.75692798 13.7730868 13.77193715 13.43313595 13.33298027 (28) 0.334802605 0.334219766 0.334247808 0.33382767 0.334282867 0.337666799 0.337638614 0.33855705 0.336032814 (29) 5.413567446 5.678981485 13.57719217 116.2151675 17.3181654 5.104524885 6.672478302 6.832518768 7.618444149 (30) 1.593139861 1.616863472 1.662464863 1.724781066 1.690577461 1.472871257 1.494599697 1.510346489 1.547712984 (31) 0.379279546 0.378619279 0.378651047 0.378175095 0.378690763 0.385387858 0.38535569 0.386403925 0.383522949 (32) 0.148269216 0.192942992 0.155515659 0.148263553 0.173175264 0.059958522 -0.079486514 -0.018919669 -0.338243146 (33) 0.552850793 0.615237809 0.577128991 0.5464518 0.592819873 0.538026762 0.453762884 0.51186199 0.508045615 (34) 0.052526526 0.052435085 0.052439185 0.05237357 0.020977994 0.085286657 0.098497685 0.09918184 0.098740116 (35) 1.605258848 1.645560978 1.6979328 1.670807342 1.70721122 1.791259678 1.646998209 1.647334428 1.557300104 (36) 11.77520748 11.75470867 11.75569493 11.74091842 11.75692798 12.30479788 12.30377079 11.72691511 11.63948079 (37) 0.6335962 0.681695847 0.127261659 0.077818798 0.208808602 0.563755367 0.496888742 0.496551337 0.496551337 (38) 14.07748713 14.05298041 14.0541595 14.0364939 14.05563364 13.23035666 13.22925231 13.26523822 13.16633437 (39) 0.671348853 0.68710832 0.824920896 0.799308189 0.804453844 0.465014463 0.464411723 0.499903096 0.496175885 (40) -1.285255063 -1.241321189 -1.573184545 -1.571207106 -1.468459586 -1.279478269 -1.258334381 -1.244943113 -1.235660983 (41) 0.340121021 0.339528923 0.339557411 0.339130599 0.339593027 0.337835424 0.337807224 0.33872612 0.336200623 (42) 1.922902073 1.917559781 1.816631128 1.814317685 1.82906106 1.983158568 1.979493901 1.973789593 1.959073281

[0255] In the basic lens data of each embodiment, the number i (i is a natural number) in the lens specification is the surface number marked in order from the object side on all the lenses, the aperture stop 170, and the first flat plate 180a and the second flat plate 180b included in the photographing lens 10. Ri is the radius of curvature of the i-th surface. Di is the interval between the i-th surface and the i+1-th surface on the optical axis Ax. Nd is the refractive index with respect to the d-line. νd is the Abbe number with respect to the d-line.

[0256] In all the values ​​of the following specifications, the units of the lengths such as the radius of curvature Ri and the surface interval Di are expressed in millimeters (mm) unless otherwise specified, and are omitted in the tables. However, in the imaging lens 10, the same optical performance can be obtained in scaling up and scaling down, so it is not limited to this.

[0257] When the direction from the object side to the image side is set to positive, k is set to the cone coefficient, A is set to the 4th-order aspheric coefficient, B is set to the 6th-order aspheric coefficient, C is set to the 8th-order aspheric coefficient, and D is set to the 10th-order aspheric coefficient, the shape of the aspheric surface of the lens described in the following embodiments is expressed by the following mathematical formula (16), i.e., the aspheric surface equation. In which h represents the height of the light, c represents the inverse of the central curvature radius, and Z represents the depth from the tangent plane to the vertex of the surface.

[0258] [Mathematical formula 1]

[0259]

[0260] The aspherical surface data in the following examples represent aspherical surface coefficients and the like, and these aspherical surface coefficients determine the aspherical surface shapes of the lens surfaces marked with * in the basic lens data.

[0261] (Example 1)

[0262] Figure 1 1 is a lens configuration diagram of the imaging lens 10 according to Example 1 of the present disclosure. Figure 1 This is a diagram showing the lens structure of the imaging lens 10 according to Example 1 in optical cross section.

[0263] like Figure 1 As shown, in the photographing lens 10 of Example 1, the first lens 110 is a biconcave lens having negative refractive power and a spherical shape. The second lens 120 is a biconcave lens having negative refractive power and a spherical shape. The third lens 130 is a biconvex lens having positive refractive power and a spherical shape. The fourth lens 140 is a biconvex lens having positive refractive power and a spherical shape. The fifth lens 150 is a biconcave lens having negative refractive power and a spherical shape. The sixth lens 160 is a biconvex lens having positive refractive power and an aspherical shape.

[0264] exist Figure 1 , D1 corresponds to the axial thickness of the first lens 110, and is the distance on the optical axis Ax between the surface S1 and the surface S2. D2 is the axial distance between the surface S2 and the surface S3. D3 corresponds to the axial thickness of the second lens 120, and is the distance on the optical axis Ax between the surface S3 and the surface S4. D4 is the axial distance between the surface S4 and the surface S5. D5 corresponds to the axial thickness of the third lens 130, and is the distance on the optical axis Ax between the surface S5 and the surface S6. D6 is the axial distance between the surface S6 and the surface S7. D7 is the axial distance between the surface S7 and the surface S8.

[0265] D8 corresponds to the axial thickness of the fourth lens 140, and is the distance on the optical axis Ax between the surface S8 and the surface S9. D9 corresponds to the axial thickness of the fifth lens 150, and is the distance on the optical axis Ax between the surface S9 and the surface S10. D10 is the axial distance between the surface S10 and the surface S11. D11 corresponds to the axial thickness of the sixth lens 160, and is the distance on the optical axis Ax between the surface S11 and the surface S12. D12 is the axial distance between the surface S12 and the surface S13. D13 corresponds to the axial thickness of the first flat plate 180a, and is the distance on the optical axis Ax between the surface S13 and the surface S14. D14 is the axial distance between the surface S14 and the surface S15. D15 corresponds to the axial thickness of the second flat plate 180b, and is the distance on the optical axis Ax between the surface S15 and the surface S16. D16 is the axial distance between the surface S16 and the image plane 21.

[0266] The above description about the surface interval Di is also applicable to the following other embodiments. Figure 1 It is shown in the figure and omitted in other figures.

[0267] Table 3 shows basic lens data including specification values ​​of the imaging lens 10 according to Example 1. In Table 3, for the aspherical surfaces S11 and S12 indicated by *, the value of the curvature radius Ri indicates the paraxial curvature radius.

[0268] [Table 3]

[0269]

[0270] ※Aspherical surface

[0271] Table 4 shows aspherical surface data including aspherical surface coefficients of the imaging lens 10 according to Example 1. The aspherical surface data shown in Table 4 are data for each of the surfaces S11 and S12 of the sixth lens 160 .

[0272] [Table 4]

[0273]

[0274] Figure 2A and Figure 2B yes Figure 1 Aberration diagram of the taking lens 10.

[0275] Figure 2A Yes means Figure 1 FIG. 1 is a graph showing the astigmatism of the photographing lens 10. Figure 2A In the figure, the vertical axis represents the incident height on the entrance pupil with the pupil diameter normalized to 1, and the horizontal axis represents the offset of the imaging position. Each line in the figure represents the astigmatism (mm) of the light of each wavelength band shown on the right side of the figure. "S" refers to the value of the sagittal image plane, and "T" refers to the value of the meridional image plane.

[0276] Figure 2B Yes means Figure 1 Graph showing the distortion of the photographing lens 10. Figure 2B In FIG. 1 , the vertical axis represents the incident height on the entrance pupil normalized to 1, and the horizontal axis represents the deviation of the imaging position. Each line in the figure represents the distortion (%) of light in each wavelength band shown on the right side of the figure.

[0277] like Figure 2A and Figure 2B As shown, according to Example 1, each aberration of astigmatism and distortion can be corrected favorably, and the imaging lens 10 having excellent imaging performance can be obtained.

[0278] The above description on the aberration diagrams is also applicable to the aberration diagrams shown in other embodiments, and therefore the description is omitted below.

[0279] (Example 2)

[0280] Figure 3 2 is a lens configuration diagram of an imaging lens 10 according to Example 2 of the present disclosure. Figure 3 This is a diagram showing the lens structure of the imaging lens 10 according to Example 2 in optical cross section.

[0281] like Figure 3 As shown, in the photographing lens 10 of Example 2, the first lens 110 is a biconcave lens having negative refractive power and a spherical shape. The second lens 120 is a biconcave lens having negative refractive power and a spherical shape. The third lens 130 is a biconvex lens having positive refractive power and a spherical shape. The fourth lens 140 is a biconvex lens having positive refractive power and a spherical shape. The fifth lens 150 is a biconcave lens having negative refractive power and a spherical shape. The sixth lens 160 is a biconvex lens having positive refractive power and an aspherical shape.

[0283] Table 5 shows basic lens data including specification values ​​of the imaging lens 10 according to Example 2. In Table 5, for the aspherical surfaces S11 and S12 indicated by *, the value of the curvature radius Ri indicates the paraxial curvature radius.

[0284] [Table 5]

[0285]

[0286] ※Aspherical surface

[0287] Table 6 shows aspherical surface data including aspherical surface coefficients of the imaging lens 10 according to Example 2. The aspherical surface data shown in Table 6 are data for each of the surfaces S11 and S12 of the sixth lens 160 .

[0288] [Table 6]

[0289]

[0290] Figure 4A and Figure 4B yes Figure 3 Aberration diagram of the taking lens 10. Figure 4A Yes means Figure 3 FIG. 1 is a graph showing astigmatism of the taking lens 10 . Figure 4B Yes means Figure 3 The distortion curve of the photographing lens 10 is shown in FIG. Figure 4A and Figure 4B As shown, according to Example 2, each aberration of astigmatism and distortion can be corrected favorably, and the imaging lens 10 having excellent imaging performance can be obtained.

[0291] (Example 3)

[0292] Figure 5 1 is a lens configuration diagram of an imaging lens 10 according to Example 3 of the present disclosure. Figure 5 This is a diagram showing the lens structure of the imaging lens 10 according to Example 3 in optical cross section.

[0293] like Figure 5 As shown, in the photographing lens 10 of Example 3, the first lens 110 is a biconcave lens having negative refractive power and a spherical shape. The second lens 120 is a biconcave lens having negative refractive power and a spherical shape. The third lens 130 is a biconvex lens having positive refractive power and a spherical shape. The fourth lens 140 is a biconvex lens having positive refractive power and a spherical shape. The fifth lens 150 is a biconcave lens having negative refractive power and a spherical shape. The sixth lens 160 is a biconvex lens having positive refractive power and an aspherical shape.

[0294] Table 7 shows basic lens data including specification values ​​of the imaging lens 10 according to Example 3. In Table 7, for the aspherical surfaces S11 and S12 indicated by *, the value of the curvature radius Ri indicates the paraxial curvature radius.

[0295] [Table 7]

[0296]

[0297] ※Aspherical surface

[0298] Table 8 shows aspherical surface data including aspherical surface coefficients of the imaging lens 10 according to Example 3. The aspherical surface data shown in Table 8 are data for each of the surfaces S11 and S12 of the sixth lens 160 .

[0299] [Table 8]

[0300]

[0301] Fig. 6A and Figure 6B yes Figure 5 Aberration diagram of the taking lens 10. Fig. 6A Yes means Figure 5 FIG. 1 is a graph showing astigmatism of the taking lens 10 . Figure 6B Yes means Figure 5 The distortion curve of the photographing lens 10 is shown in FIG. Fig. 6A and Figure 6B As shown, according to Example 3, each aberration of astigmatism and distortion can be corrected well, and the imaging lens 10 with excellent imaging performance can be obtained.

[0302] (Example 4)

[0303] Figure 7 1 is a lens configuration diagram of an imaging lens 10 according to Example 4 of the present disclosure. Figure 7 This is a diagram showing the lens structure of the imaging lens 10 according to Example 4 in optical cross section.

[0304] like Figure 7 As shown, in the photographing lens 10 of Example 4, the first lens 110 is a biconcave lens having negative refractive power and a spherical shape. The second lens 120 is a biconcave lens having negative refractive power and a spherical shape. The third lens 130 is a biconvex lens having positive refractive power and a spherical shape. The fourth lens 140 is a biconvex lens having positive refractive power and a spherical shape. The fifth lens 150 is a biconcave lens having negative refractive power and a spherical shape. The sixth lens 160 is a biconvex lens having positive refractive power and an aspherical shape.

[0305] Table 9 shows basic lens data including specification values ​​of the imaging lens 10 according to Example 4. In Table 9, for the aspherical surfaces S11 and S12 indicated by *, the value of the curvature radius Ri indicates the paraxial curvature radius.

[0306] [Table 9]

[0307]

[0308] ※Aspherical surface

[0309] Table 10 shows aspherical surface data including aspherical surface coefficients of the imaging lens 10 according to Example 4. The aspherical surface data shown in Table 10 are data for each of the surfaces S11 and S12 of the sixth lens 160 .

[0310] [Table 10]

[0311]

[0312] Fig. 8A and Figure 8B yes Figure 7 Aberration diagram of the taking lens 10. Fig. 8A Yes means Figure 7 FIG. 1 is a graph showing astigmatism of the taking lens 10 . Figure 8B Yes means Figure 7 The distortion curve of the photographing lens 10 is shown in FIG. Fig. 8A and Figure 8B As shown, according to Example 4, each aberration of astigmatism and distortion can be corrected well, and the imaging lens 10 with excellent imaging performance can be obtained.

[0313] (Example 5)

[0314] Fig. 9 1 is a lens configuration diagram of an imaging lens 10 according to Example 5 of the present disclosure. Fig. 9 This is a diagram showing the lens structure of the imaging lens 10 according to Example 5 in optical cross section.

[0315] like Fig. 9 As shown, in the photographing lens 10 of Example 5, the first lens 110 is a biconcave lens having negative refractive power and a spherical shape. The second lens 120 is a biconcave lens having negative refractive power and a spherical shape. The third lens 130 is a biconvex lens having positive refractive power and a spherical shape. The fourth lens 140 is a biconvex lens having positive refractive power and a spherical shape. The fifth lens 150 is a biconcave lens having negative refractive power and a spherical shape. The sixth lens 160 is a biconvex lens having positive refractive power and an aspherical shape.

[0316] Table 11 shows basic lens data including specification values ​​of the imaging lens 10 according to Example 5. In Table 11, for the aspherical surfaces S11 and S12 indicated by *, the value of the curvature radius Ri indicates the paraxial curvature radius.

[0317] [Table 11]

[0318]

[0319] ※Aspherical surface

[0320] Table 12 shows aspherical surface data including aspherical surface coefficients of the imaging lens 10 according to Example 5. The aspherical surface data shown in Table 12 are data for each of the surfaces S11 and S12 of the sixth lens 160 .

[0321] [Table 12]

[0322]

[0323] Fig. 10A and Fig. 10B yes Fig. 9 Aberration diagram of the taking lens 10. Fig. 10A Yes means Fig. 9 FIG. 1 is a graph showing astigmatism of the taking lens 10 . Fig. 10B Yes means Fig. 9 The distortion curve of the photographing lens 10 is shown in FIG. Fig. 10A and Fig. 10B As shown, according to Example 5, each aberration of astigmatism and distortion can be corrected well, and the imaging lens 10 with excellent imaging performance can be obtained.

[0324] (Example 6)

[0325] Fig.11 1 is a lens configuration diagram of an imaging lens 10 according to Example 6 of the present disclosure. Fig.11 This is a diagram showing the lens structure of the imaging lens 10 according to Example 6 in optical cross section.

[0326] like Fig.11 As shown, in the photographing lens 10 of Example 6, the first lens 110 is a biconcave lens having negative refractive power and a spherical shape. The second lens 120 is a biconcave lens having negative refractive power and a spherical shape. The third lens 130 is a biconvex lens having positive refractive power and a spherical shape. The fourth lens 140 is a biconvex lens having positive refractive power and a spherical shape. The fifth lens 150 is a biconcave lens having negative refractive power and a spherical shape. The sixth lens 160 is a biconvex lens having positive refractive power and an aspherical shape.

[0327] Table 13 shows basic lens data including specification values ​​of the imaging lens 10 according to Example 6. In Table 13, for the aspherical surfaces S11 and S12 indicated by *, the value of the curvature radius Ri indicates the paraxial curvature radius.

[0328] [Table 13]

[0329]

[0330] ※Aspherical surface

[0331] Table 14 shows aspherical surface data including aspherical surface coefficients of the imaging lens 10 according to Example 6. The aspherical surface data shown in Table 14 are data for each of the surfaces S11 and S12 of the sixth lens 160 .

[0332] [Table 14]

[0333]

[0334] Fig. 12A and Fig. 12B yes Fig.11 Aberration diagram of the taking lens 10. Fig. 12A Yes means Fig.11 FIG. 1 is a graph showing astigmatism of the taking lens 10 . Fig. 12B Yes means Fig.11 The distortion curve of the photographing lens 10 is shown in FIG. Fig. 12A and Fig. 12B As shown, according to Example 6, each aberration of astigmatism and distortion can be corrected favorably, and the imaging lens 10 having excellent imaging performance can be obtained.

[0335] (Example 7)

[0336] Fig.13 1 is a lens configuration diagram of an imaging lens 10 according to Example 7 of the present disclosure. Fig.13 This is a diagram showing the lens structure of the imaging lens 10 according to Example 7 in optical cross section.

[0337] like Fig.13 As shown, in the photographing lens 10 of Example 7, the first lens 110 is a biconcave lens having negative refractive power and a spherical shape. The second lens 120 is a biconcave lens having negative refractive power and a spherical shape. The third lens 130 is a biconvex lens having positive refractive power and a spherical shape. The fourth lens 140 is a biconvex lens having positive refractive power and a spherical shape. The fifth lens 150 is a biconcave lens having negative refractive power and a spherical shape. The sixth lens 160 is a biconvex lens having positive refractive power and an aspherical shape.

[0338] Table 15 shows basic lens data including specification values ​​of the imaging lens 10 according to Example 7. In Table 15, for the aspherical surfaces S11 and S12 indicated by *, the value of the curvature radius Ri indicates the paraxial curvature radius.

[0339] [Table 15]

[0340]

[0341] ※Aspherical surface

[0342] Table 16 shows aspherical surface data including aspherical surface coefficients of the imaging lens 10 according to Example 7. The aspherical surface data shown in Table 16 are data for each of the surfaces S11 and S12 of the sixth lens 160 .

[0343] [Table 16]

[0344]

[0345] Fig.14A and Fig. 14B yes Fig.13 Aberration diagram of the taking lens 10. Fig.14A Yes means Fig.13 FIG. 1 is a graph showing astigmatism of the taking lens 10 . Fig. 14B Yes means Fig.13 The distortion curve of the photographing lens 10 is shown in FIG. Fig.14A and Fig. 14B As shown, according to Example 7, each aberration of astigmatism and distortion can be corrected well, and the imaging lens 10 with excellent imaging performance can be obtained.

[0346] (Example 8)

[0347] Fig.15 1 is a lens configuration diagram of an imaging lens 10 according to Example 8 of the present disclosure. Fig.15 This is a diagram showing the lens structure of the imaging lens 10 according to Example 8 in optical cross section.

[0348] like Fig.15 As shown, in the photographing lens 10 of Example 8, the first lens 110 is a biconcave lens having negative refractive power and a spherical shape. The second lens 120 is a biconcave lens having negative refractive power and a spherical shape. The third lens 130 is a biconvex lens having positive refractive power and a spherical shape. The fourth lens 140 is a biconvex lens having positive refractive power and a spherical shape. The fifth lens 150 is a biconcave lens having negative refractive power and a spherical shape. The sixth lens 160 is a biconvex lens having positive refractive power and an aspherical shape.

[0349] Table 17 shows basic lens data including specification values ​​of the imaging lens 10 according to Example 8. In Table 17, for the aspherical surfaces S11 and S12 indicated by *, the value of the curvature radius Ri indicates the paraxial curvature radius.

[0350] [Table 17]

[0351]

[0352] ※Aspherical surface

[0353] Table 18 shows aspherical surface data including aspherical surface coefficients of the imaging lens 10 according to Example 8. The aspherical surface data shown in Table 18 are data for each of the surfaces S11 and S12 of the sixth lens 160 .

[0354] [Table 18]

[0355]

[0356] Fig.16A and Fig. 16B yes Fig.15 Aberration diagram of the taking lens 10. Fig.16A Yes means Fig.15 FIG. 1 is a graph showing astigmatism of the taking lens 10 . Fig. 16B Yes means Fig.15 The distortion curve of the photographing lens 10 is shown in FIG. Fig.16A and Fig. 16BAs shown, according to Example 8, each aberration of astigmatism and distortion can be corrected well, and the imaging lens 10 with excellent imaging performance can be obtained.

[0357] (Example 9)

[0358] Fig.17 1 is a lens configuration diagram of an imaging lens 10 according to Example 9 of the present disclosure. Fig.17 This is a diagram showing the lens structure of the imaging lens 10 according to Example 9 in optical cross section.

[0359] like Fig.17 As shown, in the photographing lens 10 of Example 9, the first lens 110 is a biconcave lens having negative refractive power and a spherical shape. The second lens 120 is a biconcave lens having negative refractive power and a spherical shape. The third lens 130 is a biconvex lens having positive refractive power and a spherical shape. The fourth lens 140 is a biconvex lens having positive refractive power and a spherical shape. The fifth lens 150 is a biconcave lens having negative refractive power and a spherical shape. The sixth lens 160 is a biconvex lens having positive refractive power and an aspherical shape.

[0360] Table 19 shows basic lens data including specification values ​​of the imaging lens 10 according to Example 9. In Table 19, for the aspherical surfaces S11 and S12 indicated by *, the value of the curvature radius Ri indicates the paraxial curvature radius.

[0361] [Table 19]

[0362]

[0363] ※Aspherical surface

[0364] Table 20 shows aspherical surface data including aspherical surface coefficients of the imaging lens 10 according to Example 9. The aspherical surface data shown in Table 20 are data for each of the surfaces S11 and S12 of the sixth lens 160 .

[0365] [Table 20]

[0366]

[0367] Fig.18A and Fig.18B yes Fig.17 Aberration diagram of the taking lens 10. Fig.18A Yes means Fig.17 FIG. 1 is a graph showing astigmatism of the taking lens 10 . Fig.18B Yes means Fig.17 The distortion curve of the photographing lens 10 is shown in FIG. Fig.18A and Fig.18B As shown, according to Example 9, each aberration of astigmatism and distortion can be corrected well, and the imaging lens 10 with excellent imaging performance can be obtained.

[0368] According to the photographing lens 10 and the photographing device 1 involved in one embodiment of the present disclosure as described above, a compact, lightweight and inexpensive structure can be achieved by a six-piece structure, and a high optical performance can be achieved by appropriately setting the shape of the lens. As a result, a compact photographing lens 10 and a photographing device 1 having a high optical performance that can be mounted on cameras including surveillance cameras and vehicle-mounted cameras can be achieved.

[0369] By satisfying the conditional expression (1), the imaging lens 10 can easily correct astigmatism and suppress the occurrence of field curvature. By satisfying the conditional expression (2), the imaging lens 10 can easily reduce focus displacement due to temperature changes.

[0370] By satisfying the conditional expression (3), the imaging lens 10 can easily correct astigmatism and process the first lens 110 , and can also suppress damage to the first lens 110 caused by the holder or the like.

[0371] By satisfying the conditional expression (4), the imaging lens 10 can easily correct the axial chromatic aberration of the entire imaging lens 10 .

[0372] In the imaging lens 10 , both surfaces of the second lens 120 are concave surfaces, and thus a flat receiving portion that can contact the first lens 110 and the spacer in a flat surface can be easily formed without performing additional processing on the second lens 120 .

[0373] The imaging lens 10 can easily correct spherical aberration by satisfying the conditional expression (5).

[0374] The imaging lens 10 can suppress the occurrence of field curvature by satisfying the conditional expression (6).

[0375] The imaging lens 10 can suppress the occurrence of lateral chromatic aberration by satisfying the conditional expression (7). In addition, the imaging lens 10 can correct the axial chromatic aberration of the entire imaging lens 10 .

[0376] The imaging lens 10 can suppress the occurrence of spherical aberration by satisfying the conditional expression (8).

[0377] In the imaging lens 10, by making the object side surface of the first lens 110 concave, a structure to be held by a holder or the like can be easily formed without additional processing of the first lens 110. In addition, the imaging lens 10 can suppress the occurrence of ghost images.

[0378] The imaging lens 10 can suppress astigmatism by satisfying conditional expression (9). In addition, the imaging lens 10 can be miniaturized in the overall length direction and radial direction, and the degree of freedom in the design of the camera housing can be increased.

[0379] The imaging lens 10 can suppress the occurrence of field curvature by satisfying the conditional expression (10). In addition, the imaging lens 10 can also correct longitudinal chromatic aberration well.

[0380] By satisfying the conditional expression (11), the imaging lens 10 can suppress the occurrence of field curvature and easily correct the axial chromatic aberration generated in the third lens 130 .

[0381] The imaging lens 10 can realize an optical system with low tolerance sensitivity by forming the fourth lens 140 and the fifth lens 150 as a cemented lens. In addition, the imaging lens 10 can reduce the workload of assembling the imaging lens 10 .

[0382] The imaging lens 10 can easily adjust the incident angle of light to the imaging element 20 by making both surfaces of the sixth lens 160 aspherical. As a result, the imaging lens 10 can easily correct spherical aberration and astigmatism.

[0383] The imaging lens 10 can easily correct field curvature by satisfying the conditional expression (12). In addition, the imaging lens 10 can also reduce tolerance sensitivity.

[0384] The photographing lens 10 can suppress yellowing due to ultraviolet rays and changes in optical characteristics due to temperature changes by forming the first lens 110 , the second lens 120 , the third lens 130 , the fourth lens 140 , the fifth lens 150 and the sixth lens 160 from glass materials.

[0385] By satisfying conditional expression (13), the photographing lens 10 can easily ensure a photographing range that should be satisfied by the photographing device 1 used in, for example, a vehicle-mounted camera.

[0386] By satisfying the conditional expression (14), the imaging lens 10 can suppress the occurrence of lateral chromatic aberration in the reverse direction and can also easily correct axial chromatic aberration.

[0387] By satisfying the conditional expression (15), the imaging lens 10 can easily correct the field curvature and can also easily correct the longitudinal chromatic aberration caused by the negative fifth lens 150 .

[0388] The imaging lens 10 can easily correct longitudinal chromatic aberration by satisfying the conditional expression (16). The imaging lens 10 can suppress the occurrence of field curvature and longitudinal chromatic aberration by satisfying the conditional expression (17).

[0389] By satisfying the conditional expression (18), the imaging lens 10 can suppress the image plane 21 from tilting toward the image side.

[0390] By satisfying the conditional expression (19), the imaging lens 10 can easily correct axial chromatic aberration and suppress the occurrence of astigmatism.

[0391] By satisfying the conditional expression (20), the imaging lens 10 can suppress the occurrence of spherical aberration and the inclination of the image plane 21 toward the image side.

[0392] By satisfying the conditional expression (21), the imaging lens 10 can correct the axial chromatic aberration in the entire optical system.

[0393] By satisfying the conditional expression (22), the imaging lens 10 can suppress the occurrence of astigmatism and the inclination of the image plane 21 in the meridional direction toward the object side.

[0394] The imaging lens 10 can suppress the generation of astigmatism and field curvature by satisfying the conditional expression (23). The imaging lens 10 can suppress the generation of field curvature by satisfying the conditional expression (24). In addition, the imaging lens 10 can correct astigmatism.

[0395] By satisfying conditional expression (25), the imaging lens 10 can suppress the occurrence of lateral chromatic aberration.

[0396] By satisfying conditional expression (26), the imaging lens 10 can suppress the occurrence of axial chromatic aberration.

[0397] By satisfying conditional expression (27), the imaging lens 10 can suppress the occurrence of axial chromatic aberration.

[0398] By satisfying the conditional expression (28), the imaging lens 10 can easily ensure a back focus and suppress the occurrence of field curvature.

[0399] By satisfying conditional expression (29), the imaging lens 10 can suppress the occurrence of axial chromatic aberration.

[0400] The imaging lens 10 can suppress the generation of astigmatism and the inclination of the image plane 21 toward the object side in the tangential direction by satisfying the conditional expression (30). The imaging lens 10 can correct the longitudinal chromatic aberration by satisfying the conditional expression (31).

[0401] The imaging lens 10 can suppress the occurrence of astigmatism by satisfying the conditional expression (32). In addition, the imaging lens 10 can easily correct axial chromatic aberration.

[0402] The imaging lens 10 can suppress the occurrence of astigmatism by satisfying the conditional expression (33). In addition, the imaging lens 10 can suppress the curvature of the image plane 21 in the tangential direction.

[0403] By satisfying the conditional expression (34), the imaging lens 10 can suppress the incident angle of the light incident on the image plane 21 .

[0404] The imaging lens 10 can suppress the occurrence of astigmatism by satisfying the conditional expression (35).

[0405] The imaging lens 10 can easily correct lateral chromatic aberration by satisfying the conditional expression (36). In addition, the imaging lens 10 can easily achieve low cost by selecting an inexpensive material.

[0406] By satisfying the conditional expression (37), the imaging lens 10 can easily correct astigmatism and suppress the generation of field curvature. By satisfying the conditional expression (38), the imaging lens 10 can correct the axial chromatic aberration generated in the fourth lens 140 by the fifth lens 150. In addition, the imaging lens 10 can easily achieve low cost by selecting inexpensive materials.

[0407] The imaging lens 10 can correct lateral chromatic aberration by satisfying the conditional expression (39). In addition, the refractive power of the sixth lens 160 of the imaging lens 10 does not become too large, and the occurrence of field curvature can be suppressed.

[0408] The imaging lens 10 can reduce tolerance sensitivity by satisfying the conditional expression (40). In addition, the imaging lens 10 can appropriately correct astigmatism.

[0409] The imaging lens 10 can easily correct lateral chromatic aberration by satisfying the conditional expression (41). In addition, the imaging lens 10 can increase the degree of freedom in selecting the material of the sixth lens 160 .

[0410] When the imaging lens 10 satisfies the conditional expression (42), it is easy to arrange the optical components in the imaging lens 10 and to configure the optical system.

[0411] It will be apparent to those skilled in the art that the present disclosure can be implemented in other specified ways other than the above-described embodiments without departing from its spirit or its essential features. Therefore, the foregoing description is illustrative rather than restrictive. The scope of the present disclosure is defined by the appended claims rather than by the foregoing description. All changes that are within their equivalent ranges are included in the present disclosure.

[0412] For example, the shape, size, arrangement, orientation and number of the above-mentioned components are not limited to the above-mentioned description and the contents of the drawings. The shape, size, arrangement, orientation and number of the above-mentioned components can be arbitrarily configured as long as they can achieve their functions.

[0413] The photographing lens 10 involved in one embodiment has been described, but the present disclosure is not limited to the photographing lens 10 of the above-mentioned embodiments, and various modifications can be made within the scope of the invention. For example, the specifications of the photographing lens 10 of each embodiment are examples, and various parameters can be changed within the scope of the present disclosure.

[0414] A part of the embodiments of the present disclosure is exemplified below, but it should be noted that the embodiments of the present disclosure are not limited thereto.

[0415] [Note 1]

[0416] A photographing lens, wherein

[0417] The invention comprises, in order from the object side, a first lens having negative refractive power, a second lens having negative refractive power, a third lens having positive refractive power, an aperture stop, a fourth lens having positive refractive power, a fifth lens having negative refractive power, and a sixth lens having positive refractive power.

[0418] When the curvature radius of the object side surface of the first lens is set to R1, the curvature radius of the image side surface of the first lens is set to R2, the refractive index temperature coefficient of the fourth lens in the temperature range of 20°C to 40°C with respect to the d-line is set to dN4 / dT, the refractive index temperature coefficient of the sixth lens in the temperature range of 20°C to 40°C with respect to the d-line is set to dN6 / dT, and the focal length of the photographing lens with respect to the d-line is set to f, the following conditional expression is satisfied:

[0419] 0.6<(R1+R2) / (R1-R2)<0.8 (1)

[0420] -1.1<(dN4 / dT+dN6 / dT) / f<-0.7 (2).

[0421] [Note 2]

[0422] The imaging lens according to Supplementary Note 1, wherein:

[0423] When the axial thickness of the first lens is set to D1, the following conditional expression is satisfied:

[0424] 0.14<D1 / f (3).

[0425] [Note 3]

[0426] The imaging lens according to Supplementary Note 1 or 2, wherein:

[0427] When the focal length of the second lens relative to the d-line is set to f2, the following conditional expression is satisfied:

[0428] -3.8<f2 / f<-2 (4).

[0429] [Note 4]

[0430] The imaging lens according to any one of Supplementary Notes 1 to 3, wherein:

[0431] The two surfaces of the second lens are respectively concave surfaces.

[0432] [Note 5]

[0433] The imaging lens according to any one of Supplementary Notes 1 to 4, wherein:

[0434] When the axial distance from the image side surface of the first lens to the object side surface of the second lens is set to D2, the following conditional expression is satisfied:

[0435] 0.36<D2 / f<0.6 (5).

[0436] [Note 6]

[0437] The imaging lens according to any one of Supplementary Notes 1 to 5, wherein:

[0438] The following conditions are met:

[0439] -6.7<R1 / f<-4.4 (6).

[0440] [Note 7]

[0441] The imaging lens according to any one of Supplementary Notes 1 to 6, wherein:

[0442] When the Abbe number of the third lens is set to ν3, the following conditional expression is satisfied:

[0443] 4.7<ν3 / f<5.7 (7).

[0444] [Note 8]

[0445] The imaging lens according to any one of Supplementary Notes 1 to 7, wherein:

[0446] When the refractive index of the first lens is set to N1, the following conditional formula is satisfied:

[0447] N1 / f<0.34 (8).

[0448] [Note 9]

[0449] The imaging lens according to any one of Supplementary Notes 1 to 8, wherein:

[0450] The object side surface of the first lens is a concave surface.

[0451] [Note 10]

[0452] The imaging lens according to any one of Supplementary Notes 1 to 9, wherein:

[0453] When the total length of the photographing lens on the axis is Da, the following conditional expression is satisfied: Da / f<5.2 (9).

[0454] [Note 11]

[0455] The imaging lens according to any one of Supplementary Notes 1 to 10, wherein:

[0456] When the focal length of the first lens with respect to the d-line is set to f1, the following conditional expression is satisfied: -1.5<f1 / f<-1.2 (10).

[0457] [Note 12]

[0458] The imaging lens according to any one of Supplementary Notes 1 to 11, wherein:

[0459] When the focal length of the third lens with respect to the d-line is set to f3, the following conditional expression is satisfied: 1.6<f3 / f<3.1 (11).

[0460] [Note 13]

[0461] The photographing lens according to any one of Supplementary Notes 1 to 12, wherein the fourth lens and the fifth lens are formed as a cemented lens.

[0462] [Note 14]

[0463] The imaging lens according to any one of Supplementary Notes 1 to 13, wherein:

[0464] The two surfaces of the sixth lens are respectively aspherical surfaces.

[0465] [Note 15]

[0466] The imaging lens according to any one of Supplementary Notes 1 to 14, wherein:

[0467] When the focal length of the sixth lens with respect to the d-line is set to f6, the following conditional expression is satisfied: 1.45<f6 / f<1.8 (12).

[0468] [Note 16]

[0469] The imaging lens according to any one of Supplementary Notes 1 to 15, wherein:

[0470] The first lens, the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens are respectively formed of glass materials.

[0471] [Note 17]

[0472] The imaging lens according to any one of Supplementary Notes 1 to 16, wherein:

[0473] When the half viewing angle of the light incident on the image plane at the maximum image height position is set to W, the following conditional expression is satisfied:

[0474] 48<W (13).

[0475] [Note 18]

[0476] The imaging lens according to any one of Supplementary Notes 1 to 17, wherein:

[0477] When the focal length of the fifth lens relative to the d-line is set to f5, the following conditional expression is satisfied:

[0478] -2.0<f5 / f<-1.1 (14).

[0479] [Note 19]

[0480] The imaging lens according to any one of Supplementary Notes 1 to 18, wherein:

[0481] When the focal length of the fourth lens relative to the d-line is set to f4, the following conditional expression is satisfied:

[0482] 1.2<f4 / f<1.8 (15).

[0483] [Note 20]

[0484] The imaging lens according to any one of Supplementary Notes 1 to 19, wherein:

[0485] When the axial distance from the image side surface of the second lens to the object side surface of the third lens is set to D4, the focal length of the photographing lens with respect to the d-line is set to f, and the axial thickness of the second lens is set to D3, the following conditional expression is satisfied:

[0486] D4 / f<0.08 (16)

[0487] 0.12<D3 / f<0.23 (17).

[0488] [Note 21]

[0489] The imaging lens according to any one of Supplementary Notes 1 to 20, wherein:

[0490] When the refractive index of the second lens is set to N2, the following conditional formula is satisfied:

[0491] N2 / f<0.33 (18).

[0492] [Note 22]

[0493] The imaging lens according to any one of Supplementary Notes 1 to 21, wherein:

[0494] When the curvature radius of the object side surface of the second lens is set to R3, and the curvature radius of the image side surface of the second lens is set to R4, the following conditional formula is satisfied:

[0495] -1<(R3+R4) / (R3-R4)<-0.82 (19).

[0496] [Note 23]

[0497] The imaging lens according to any one of Supplementary Notes 1 to 22, wherein:

[0498] When the curvature radius of the image side surface of the first lens is set to R2, the following conditional expression is satisfied:

[0499] 0.77<R2 / f<0.9 (20).

[0500] [Note 24]

[0501] The imaging lens according to any one of Supplementary Notes 1 to 23, wherein:

[0502] When the Abbe number of the fifth lens is set to ν5, the following conditional expression is satisfied:

[0503] 4.8<ν5 / f<5.5 (21).

[0504] [Note 25]

[0505] The imaging lens according to any one of Supplementary Notes 1 to 24, wherein:

[0506] When the combined focal length of the fourth lens, the fifth lens, and the sixth lens with respect to the d-line is set to fg, the following conditional expression is satisfied:

[0507] 1.4<fg / f<1.8 (22).

[0508] [Note 26]

[0509] The imaging lens according to any one of Supplementary Notes 1 to 25, wherein:

[0510] When the curvature radius of the object side surface of the second lens is set to R3, the focal length of the photographing lens with respect to the d-line is set to f, the curvature radius of the object side surface of the third lens is set to R5, and the curvature radius of the image side surface of the third lens is set to R6, the following conditional expression is satisfied:

[0511] -2.2<R3 / f<-1.2 (23)

[0512] -0.15<(R5+R6) / (R5-R6)<0.15 (24).

[0513] [Note 27]

[0514] The imaging lens according to any one of Supplementary Notes 1 to 26, wherein:

[0515] When the axial thickness of the third lens is set to D5, the following conditional formula is satisfied:

[0516] D5 / f<0.75 (25).

[0517] [Note 28]

[0518] The imaging lens according to any one of Supplementary Notes 1 to 27, wherein:

[0519] When the axial distance from the image side surface of the third lens to the object side surface of the fourth lens is set to D6, the following conditional expression is satisfied:

[0520] 0.03<D6 / f (26).

[0521] [Note 29]

[0522] The imaging lens according to any one of Supplementary Notes 1 to 28, wherein:

[0523] When the Abbe number of the first lens is set to ν1, the following conditional expression is satisfied:

[0524] 10<ν1 / f<15 (27).

[0525] [Note 30]

[0526] The imaging lens according to any one of Supplementary Notes 1 to 29, wherein:

[0527] When the refractive index of the fourth lens is set to N4, the following conditional formula is satisfied:

[0528] N4 / f<0.4 (28).

[0529] [Note 31]

[0530] The imaging lens according to any one of Supplementary Notes 1 to 30, wherein:

[0531] When the combined focal length of the fourth lens and the fifth lens with respect to the d-line is set to fg, the following conditional expression is satisfied:

[0532] 4.8<fg / f (29).

[0533] [Note 32]

[0534] The imaging lens according to any one of Supplementary Notes 1 to 31, wherein:

[0535] When the combined focal length of the fourth lens, the fifth lens and the sixth lens with respect to the d-line is set to fg, the focal length of the photographing lens with respect to the d-line is set to f, and the refractive index of the fifth lens is set to N5, the following conditional expression is satisfied:

[0536] 1.4<fg / f<1.8 (30)

[0537] 0.35<N5 / f (31).

[0538] [Note 33]

[0539] The imaging lens according to any one of Supplementary Notes 1 to 32, wherein:

[0540] When the curvature radius of the object side surface of the fourth lens is set to R8, and the curvature radius of the image side surface of the fourth lens is set to R9, the following conditional formula is satisfied:

[0541] -0.4<(R8+R9) / (R8-R9)<0.25 (32).

[0542] [Note 34]

[0543] The imaging lens according to any one of Supplementary Notes 1 to 33, wherein:

[0544] When the axial thickness of the fourth lens is set to D8, the following conditional formula is satisfied:

[0545] 0.4<D8 / f<0.7 (33).

[0546] [Note 35]

[0547] The imaging lens according to any one of Supplementary Notes 1 to 34, wherein:

[0548] When the axial distance from the image side surface of the fifth lens to the object side surface of the sixth lens is set to D10, the following conditional expression is satisfied:

[0549] 0.015<D10 / f (34).

[0550] [Note 36]

[0551] The imaging lens according to any one of Supplementary Notes 1 to 35, wherein:

[0552] The following conditions are met:

[0553] R8 / f<1.9 (35).

[0554] [Note 37]

[0555] The imaging lens according to any one of Supplementary Notes 1 to 36, wherein:

[0556] When the Abbe number of the second lens is set to ν2, the following conditional expression is satisfied:

[0557] 11<ν2 / f (36).

[0558] [Note 38]

[0559] The imaging lens according to any one of Supplementary Notes 1 to 37, wherein:

[0560] When the curvature radius of the object side surface of the sixth lens is set to R11, the curvature radius of the image side surface of the sixth lens is set to R12, the Abbe number of the fourth lens is set to ν4, and the focal length of the photographing lens with respect to the d-line is set to f, the following conditional expression is satisfied:

[0561] 0.05<(R11+R12) / (R11-R12)<0.7 (37)

[0562] 12<ν4 / f (38)

[0563] The two surfaces of the second lens are respectively concave surfaces.

[0564] [Note 39]

[0565] The imaging lens according to any one of Supplementary Notes 1 to 38, wherein:

[0566] When the axial thickness of the sixth lens is set to D11, the following conditional formula is satisfied:

[0567] 0.4<D11 / f<0.9 (39).

[0568] [Note 40]

[0569] The imaging lens according to any one of Supplementary Notes 1 to 39, wherein:

[0570] The following conditions are met:

[0571] R12 / f<-1.2 (40).

[0572] [Note 41]

[0573] The imaging lens according to any one of Supplementary Notes 1 to 40, wherein:

[0574] When the refractive index of the sixth lens is set to N6, the following conditional formula is satisfied:

[0575] N6 / f<0.4 (41).

[0576] [Note 42]

[0577] The imaging lens according to any one of Supplementary Notes 1 to 41, wherein:

[0578] When the back focal length is set to Db, the following conditional expression is satisfied:

[0579] 1.7<Db / f (42).

[0580] [Note 43]

[0581] A photographing device, comprising:

[0582] an imaging lens including, in order from the object side, a first lens having negative refractive power, a second lens having negative refractive power, a third lens having positive refractive power, an aperture stop, a fourth lens having positive refractive power, a fifth lens having negative refractive power, and a sixth lens having positive refractive power; and

[0583] The imaging element converts the optical image formed by the imaging lens into an electrical signal.

[0584] When the curvature radius of the object side surface of the first lens is set to R1, the curvature radius of the image side surface of the first lens is set to R2, the refractive index temperature coefficient of the fourth lens in the temperature range of 20°C to 40°C with respect to the d-line is set to dN4 / dT, the refractive index temperature coefficient of the sixth lens in the temperature range of 20°C to 40°C with respect to the d-line is set to dN6 / dT, and the focal length of the photographing lens with respect to the d-line is set to f, the following conditional expression is satisfied:

[0585] 0.6<(R1+R2) / (R1-R2)<0.8 (43)

[0586] -1.1<(dN4 / dT+dN6 / dT) / f<-0.7 (44).

[0587] [Note 44]

[0588] A photographing device, comprising:

[0589] an imaging lens including, in order from the object side, a first lens having negative refractive power, a second lens having negative refractive power, a third lens having positive refractive power, an aperture stop, a fourth lens having positive refractive power, a fifth lens having negative refractive power, and a sixth lens having positive refractive power; and

[0590] The imaging element converts the optical image formed by the imaging lens into an electrical signal.

[0591] When the axial distance from the image side surface of the second lens to the object side surface of the third lens is set to D4, the focal length of the photographing lens with respect to the d-line is set to f, and the axial thickness of the second lens is set to D3, the following conditional expression is satisfied:

[0592] D4 / f<0.08 (45)

[0593] 0.12<D3 / f<0.23 (46).

[0594] [Note 45]

[0595] A photographing device, comprising:

[0596] an imaging lens including, in order from the object side, a first lens having negative refractive power, a second lens having negative refractive power, a third lens having positive refractive power, an aperture stop, a fourth lens having positive refractive power, a fifth lens having negative refractive power, and a sixth lens having positive refractive power; and

[0597] The imaging element converts the optical image formed by the imaging lens into an electrical signal.

[0598] When the curvature radius of the object side surface of the second lens is set to R3, the focal length of the photographing lens relative to the d-line is set to f, the curvature radius of the object side surface of the third lens is set to R5, and the curvature radius of the image side surface of the third lens is set to R6, the following conditional formula is satisfied:

[0599] -2.2<R3 / f<-1.2 (47)

[0600] -0.15<(R5+R6) / (R5-R6)<0.15 (48).

[0601] [Note 46]

[0602] A photographing device, comprising:

[0603] an imaging lens including, in order from the object side, a first lens having negative refractive power, a second lens having negative refractive power, a third lens having positive refractive power, an aperture stop, a fourth lens having positive refractive power, a fifth lens having negative refractive power, and a sixth lens having positive refractive power; and

[0604] The imaging element converts the optical image formed by the imaging lens into an electrical signal.

[0605] When the combined focal length of the fourth lens, the fifth lens and the sixth lens with respect to the d-line is set to fg, the focal length of the photographing lens with respect to the d-line is set to f, and the refractive index of the fifth lens is set to N5, the following conditional expression is satisfied:

[0606] 1.4<fg / f<1.8 (49)

[0607] 0.35<N5 / f (50).

[0608] [Note 47]

[0609] A photographing device, comprising:

[0610] an imaging lens including, in order from the object side, a first lens having negative refractive power, a second lens having negative refractive power, a third lens having positive refractive power, an aperture stop, a fourth lens having positive refractive power, a fifth lens having negative refractive power, and a sixth lens having positive refractive power; and

[0611] The imaging element converts the optical image formed by the imaging lens into an electrical signal.

[0612] When the curvature radius of the object side surface of the sixth lens is set to R11, the curvature radius of the image side surface of the sixth lens is set to R12, the Abbe number of the fourth lens is set to ν4, and the focal length of the photographing lens with respect to the d-line is set to f, the following conditional expression is satisfied:

[0613] 0.05<(R11+R12) / (R11-R12)<0.7 (51)

[0614] 12<ν4 / f (52)

[0615] The two surfaces of the second lens are respectively concave surfaces.

[0616] Description of Reference Numerals

[0617] 1. Shooting device

[0618] 10 Photographic lens

[0619] 110 First lens

[0620] 120 Second lens

[0621] 130 Third lens

[0622] 140 Fourth lens

[0623] 150 Fifth lens

[0624] 160 Sixth lens

[0625] 170 Aperture stop

[0626] 180a First Plate

[0627] 180b Second Plate

[0628] 20 Photographic elements

[0629] 21 Image plane

[0630] Ax Optical axis

[0631] Di surface spacing

[0632] Da Full Length

[0633] Db Back focal length

[0634] Ri Radius of curvature

[0635] Si

Claims

1. A photographing lens, wherein: The invention comprises, in order from the object side, a first lens having negative refractive power, a second lens having negative refractive power, a third lens having positive refractive power, an aperture stop, a fourth lens having positive refractive power, a fifth lens having negative refractive power, and a sixth lens having positive refractive power. When the curvature radius of the object side surface of the first lens is set to R1, the curvature radius of the image side surface of the first lens is set to R2, the refractive index temperature coefficient of the fourth lens in the temperature range of 20°C to 40°C with respect to the d-line is set to dN4 / dT, the refractive index temperature coefficient of the sixth lens in the temperature range of 20°C to 40°C with respect to the d-line is set to dN6 / dT, and the focal length of the photographing lens with respect to the d-line is set to f, the following conditional expression is satisfied: 0.6<(R1+R2) / (R1-R2)<0.8 (1) -1.1<(dN4 / dT+dN6 / dT) / f<-0.7 (2).

2. The imaging lens according to claim 1, wherein: When the axial thickness of the first lens is set to D1, the following conditional expression is satisfied: 0.14<D1 / f (3).

3. The imaging lens according to claim 1 or 2, wherein: When the focal length of the second lens relative to the d-line is set to f2, the following conditional expression is satisfied: -3.8<f2 / f<-2 (4).

4. The imaging lens according to claim 1 or 2, wherein: The two surfaces of the second lens are respectively concave surfaces.

5. The imaging lens according to claim 1 or 2, wherein: When the axial distance from the image side surface of the first lens to the object side surface of the second lens is set to D2, the following conditional expression is satisfied: 0.36<D2 / f<0.6 (5).

6. The imaging lens according to claim 1 or 2, wherein: The following conditions are met: -6.7<R1 / f<-4.4 (6).

7. The imaging lens according to claim 1 or 2, wherein: When the Abbe number of the third lens is set to ν3, the following conditional expression is satisfied: 4.7<ν3 / f<5.7 (7).

8. The imaging lens according to claim 1 or 2, wherein: When the refractive index of the first lens is set to N1, the following conditional formula is satisfied: N1 / f<0.34 (8).

9. The imaging lens according to claim 1 or 2, wherein: The object side surface of the first lens is a concave surface.

10. The imaging lens according to claim 1 or 2, wherein: When the total length of the photographing lens on the axis is set to Da, the following conditional expression is satisfied: Da / f<5.2 (9).

11. The imaging lens according to claim 1 or 2, wherein: When the focal length of the first lens relative to the d-line is set to f1, the following conditional expression is satisfied: -1.5<f1 / f<-1.2 (10).

12. The imaging lens according to claim 1 or 2, wherein: When the focal length of the third lens relative to the d-line is set to f3, the following conditional expression is satisfied: 1.6<f3 / f<3.1 (11).

13. The imaging lens according to claim 1 or 2, wherein: The fourth lens and the fifth lens are formed as a cemented lens.

14. The photographing lens according to claim 1 or 2, wherein: The two surfaces of the sixth lens are respectively aspherical surfaces.

15. The photographing lens according to claim 1 or 2, wherein: When the focal length of the sixth lens with respect to the d-line is set to f6, the following conditional expression is satisfied: 1.45<f6 / f<1.8 (12).

16. The photographing lens according to claim 1 or 2, wherein: The first lens, the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens are respectively formed of glass materials.

17. The photographing lens according to claim 1 or 2, wherein: When the half viewing angle of the light incident on the image plane at the maximum image height position is set to W, the following conditional expression is satisfied: 48＜W (13)。 18. The photographing lens according to claim 1 or 2, wherein: When the focal length of the fifth lens relative to the d-line is set to f5, the following conditional expression is satisfied: -2.0<f5 / f<-1.1 (14).

19. The photographing lens according to claim 1 or 2, wherein: When the focal length of the fourth lens relative to the d-line is set to f4, the following conditional expression is satisfied: 1.2<f4 / f<1.8 (15).

20. The photographing lens according to claim 1 or 2, wherein: When the axial distance from the image side surface of the second lens to the object side surface of the third lens is set to D4, the focal length of the photographing lens with respect to the d-line is set to f, and the axial thickness of the second lens is set to D3, the following conditional expression is satisfied: D4 / f<0.08 (16) 0.12<D3 / f<0.23 (17).

21. The photographing lens according to claim 1 or 2, wherein: When the refractive index of the second lens is set to N2, it satisfies: N2 / f<0.33 (18).

22. The photographing lens according to claim 1 or 2, wherein: When the curvature radius of the object side surface of the second lens is set to R3, and the curvature radius of the image side surface of the second lens is set to R4, the following conditional formula is satisfied: -1<(R3+R4) / (R3-R4)<-0.82 (19).

23. The photographing lens according to claim 1 or 2, wherein: When the curvature radius of the image side surface of the first lens is set to R2, the following conditional expression is satisfied: 0.77<R2 / f<0.9 (20).

24. The photographing lens according to claim 1 or 2, wherein: When the Abbe number of the fifth lens is set to ν5, the following conditional expression is satisfied: 4.8<ν5 / f<5.5 (21).

25. The photographing lens according to claim 1 or 2, wherein: When the combined focal length of the fourth lens, the fifth lens, and the sixth lens with respect to the d-line is set to fg, the following conditional expression is satisfied: 1.4<fg / f<1.8 (22).

26. The photographing lens according to claim 1 or 2, wherein: When the curvature radius of the object side surface of the second lens is set to R3, the focal length of the photographing lens with respect to the d-line is set to f, the curvature radius of the object side surface of the third lens is set to R5, and the curvature radius of the image side surface of the third lens is set to R6, the following conditional expression is satisfied: -2.2<R3 / f<-1.2 (23) -0.15<(R5+R6) / (R5-R6)<0.15 (24).

27. The photographing lens according to claim 1 or 2, wherein: When the axial thickness of the third lens is set to D5, the following conditional formula is satisfied: D5 / f<0.75 (25).

28. The photographing lens according to claim 1 or 2, wherein: When the axial distance from the image side surface of the third lens to the object side surface of the fourth lens is set to D6, the following conditional expression is satisfied: 0.03<D6 / f (26).

29. The photographing lens according to claim 1 or 2, wherein: When the Abbe number of the first lens is set to ν1, the following conditional expression is satisfied: 10<ν1 / f<15 (27).

30. The photographing lens according to claim 1 or 2, wherein: When the refractive index of the fourth lens is set to N4, the following conditional formula is satisfied: N4 / f<0.4 (28).

31. The photographing lens according to claim 1 or 2, wherein: When the combined focal length of the fourth lens and the fifth lens with respect to the d-line is set to fg, the following conditional expression is satisfied: 4.8<fg / f (29).

32. The photographing lens according to claim 1 or 2, wherein: When the combined focal length of the fourth lens, the fifth lens and the sixth lens with respect to the d-line is set to fg, the focal length of the photographing lens with respect to the d-line is set to f, and the refractive index of the fifth lens is set to N5, the following conditional expression is satisfied: 1.4<fg / f<1.8 (30) 0.35<N5 / f (31).

33. The photographing lens according to claim 1 or 2, wherein: When the curvature radius of the object-side surface of the fourth lens is set to R8, and the curvature radius of the image-side surface of the fourth lens is set to R9, the following conditional formula is satisfied: -0.4<(R8+R9) / (R8-R9)<0.25 (32).

34. The photographing lens according to claim 1 or 2, wherein: When the axial thickness of the fourth lens is set to D8, the following conditional formula is satisfied: 0.4<D8 / f<0.7 (33).

35. The photographing lens according to claim 1 or 2, wherein: When the axial distance from the image side surface of the fifth lens to the object side surface of the sixth lens is set to D10, the following conditional expression is satisfied: 0.015<D10 / f (34).

36. The photographing lens according to claim 1 or 2, wherein: The following conditions are met: R8 / f<1.9 (35).

37. The photographing lens according to claim 1 or 2, wherein: When the Abbe number of the second lens is set to ν2, the following conditional expression is satisfied: 11<ν2 / f (36).

38. The photographing lens according to claim 1 or 2, wherein: When the curvature radius of the object side surface of the sixth lens is set to R11, the curvature radius of the image side surface of the sixth lens is set to R12, the Abbe number of the fourth lens is set to ν4, and the focal length of the photographing lens with respect to the d-line is set to f, the following conditional expression is satisfied: 0.05<(R11+R12) / (R11-R12)<0.7 (37) 12<ν4 / f (38) The two surfaces of the second lens are respectively concave surfaces.

39. The photographing lens according to claim 1 or 2, wherein: When the axial thickness of the sixth lens is set to D11, the following conditional formula is satisfied: 0.4<D11 / f<0.9 (39).

40. The photographing lens according to claim 1 or 2, wherein: The following conditions are met: R12 / f<-1.2 (40).

41. The photographing lens according to claim 1 or 2, wherein: When the refractive index of the sixth lens is set to N6, the following conditional formula is satisfied: N6 / f<0.4 (41).

42. The photographing lens according to claim 1 or 2, wherein: When the back focal length is set to Db, the following conditional expression is satisfied: 1.7<Db / f (42).

43. A photographing device, wherein: have: a photographing lens including, in order from the object side, a first lens having negative refractive power, a second lens having negative refractive power, a third lens having positive refractive power, an aperture stop, a fourth lens having positive refractive power, a fifth lens having negative refractive power, and a sixth lens having positive refractive power; as well as The imaging element converts the optical image formed by the imaging lens into an electrical signal. When the curvature radius of the object side surface of the first lens is set to R1, the curvature radius of the image side surface of the first lens is set to R2, the refractive index temperature coefficient of the fourth lens in the temperature range of 20°C to 40°C with respect to the d-line is set to dN4 / dT, the refractive index temperature coefficient of the sixth lens in the temperature range of 20°C to 40°C with respect to the d-line is set to dN6 / dT, and the focal length of the photographing lens with respect to the d-line is set to f, the following conditional expression is satisfied: 0.6<(R1+R2) / (R1-R2)<0.8 (43) -1.1<(dN4 / dT+dN6 / dT) / f<-0.7 (44).

44. A photographing device, wherein: have: a photographing lens including, in order from the object side, a first lens having negative refractive power, a second lens having negative refractive power, a third lens having positive refractive power, an aperture stop, a fourth lens having positive refractive power, a fifth lens having negative refractive power, and a sixth lens having positive refractive power; as well as The imaging element converts the optical image formed by the imaging lens into an electrical signal. When the axial distance from the image side surface of the second lens to the object side surface of the third lens is set to D4, the focal length of the photographing lens with respect to the d-line is set to f, and the axial thickness of the second lens is set to D3, the following conditional expression is satisfied: D4 / f<0.08 (45) 0.12<D3 / f<0.23 (46).

45. A photographing device, wherein: have: a photographing lens including, in order from the object side, a first lens having negative refractive power, a second lens having negative refractive power, a third lens having positive refractive power, an aperture stop, a fourth lens having positive refractive power, a fifth lens having negative refractive power, and a sixth lens having positive refractive power; as well as The imaging element converts the optical image formed by the imaging lens into an electrical signal. When the curvature radius of the object side surface of the second lens is set to R3, the focal length of the photographing lens with respect to the d-line is set to f, the curvature radius of the object side surface of the third lens is set to R5, and the curvature radius of the image side surface of the third lens is set to R6, the following conditional expression is satisfied: -2.2<R3 / f<-1.2 (47) -0.15<(R5+R6) / (R5-R6)<0.15 (48).

46. ​​A photographing device, wherein: have: a photographing lens including, in order from the object side, a first lens having negative refractive power, a second lens having negative refractive power, a third lens having positive refractive power, an aperture stop, a fourth lens having positive refractive power, a fifth lens having negative refractive power, and a sixth lens having positive refractive power; as well as The imaging element converts the optical image formed by the imaging lens into an electrical signal. When the combined focal length of the fourth lens, the fifth lens and the sixth lens with respect to the d-line is set to fg, the focal length of the photographing lens with respect to the d-line is set to f, and the refractive index of the fifth lens is set to N5, the following conditional expression is satisfied: 1.4<fg / f<1.8 (49) 0.35<N5 / f (50).

47. A photographing device, wherein: have: an imaging lens including, in order from the object side, a first lens having negative refractive power, a second lens having negative refractive power, a third lens having positive refractive power, an aperture stop, a fourth lens having positive refractive power, a fifth lens having negative refractive power, and a sixth lens having positive refractive power; and The imaging element converts the optical image formed by the imaging lens into an electrical signal. When the curvature radius of the object side surface of the sixth lens is set to R11, the curvature radius of the image side surface of the sixth lens is set to R12, the Abbe number of the fourth lens is set to ν4, and the focal length of the photographing lens with respect to the d-line is set to f, the following conditional expression is satisfied: 0.05<(R11+R12) / (R11-R12)<0.7 (51) 12<ν4 / f (52) The two surfaces of the second lens are respectively concave surfaces.

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