Imaging lens and imaging device

Abstract

Imaging lens consisting, in order starting from the object side, of a first lens (L1) with a negative refractive power, a second lens (L2) with a positive refractive power, a third lens (L3) with a positive refractive power, a fourth lens (L4) with a negative refractive power, a fifth lens (L5) with a positive refractive power, a sixth lens (L6) with a positive refractive power and a seventh lens (L7) with a negative refractive power, wherein the following condition formulas are satisfied: f 12 / f < − 3.2 vd 7 < 55 40 < vd 3 where, f12 is the combined focal length of the first lens (L1) and the second lens (L2), f is the focal length of the entire system, vd7 is the Abbe number of the material of the seventh lens (L7) with respect to the d-line, and vd3 is the Abbe number of the material of the third lens (L3) with respect to the d-line.

Description

BACKGROUND OF THE INVENTION Area of ​​the invention

[0001] The present invention relates to an imaging lens and an imaging device, and in particular an imaging lens suitable for use in a vehicle-based camera for taking pictures, especially in front of, to the side, behind, etc. of vehicles, in a camera of a portable terminal device and in a surveillance camera which uses image sensors such as CCDs (Charge Coupled Device), CMOSs ​​(Complementary Metal Oxide Semiconductor) and the like, and an imaging device which is equipped with this imaging lens. Description of the state of the art

[0002] In recent years, miniaturization and an increased number of pixels have been achieved in image sensors such as CCDs, CMOS, and the like. Alongside these developments, and because the size of the bodies of imaging devices equipped with these image sensors has also been miniaturized, the imaging lenses attached to them must also be miniaturized and lighter, in addition to offering favorable optical performance.

[0003] Meanwhile, lenses used in vehicle-based cameras, handheld cameras, surveillance cameras, and similar devices are required to exhibit high weather resistance, usability across a wide temperature range from ambient temperatures in cold climates to temperatures inside a vehicle in the tropics during summer, compact size, and high performance. In particular, cameras positioned inside vehicles to monitor their front require low f-numbers and usability across a wide wavelength range, from the visible to the infrared, to enable nighttime use.Furthermore, when lenses are used in vehicle-based cameras, from the perspective of the exterior image of vehicles, there is also a requirement for lens sections exposed to the outside of vehicles to be small.

[0004] The Japanese patent publication JP 2010-91697 A proposes an imaging lens with a six-lens configuration, in which a negative lens, a positive lens, a positive lens, a negative lens, a positive lens and a positive lens are arranged in order starting from the object side, as imaging lenses to be attached to vehicle-based cameras.

[0005] Furthermore, US patent 8,797,659 B2 discloses a focusing macro lens with three different lens groups, in which focusing is achieved by fixing the first lens group and the second lens group and by moving the second lens group with a positive refractive power as a whole on the optical axis when focusing from an infinity object to an object at a short distance. SUMMARY OF THE INVENTION

[0006] The requirements for imaging lenses for mounting on vehicle-based cameras, surveillance cameras and the like are becoming stricter year by year, and it is therefore desirable for the imaging lens disclosed in JP 2010-91697 A to have a smaller F-number and achieve higher performance.

[0007] The present invention was developed in light of the aforementioned circumstances. The object of the present invention is to provide an imaging lens with a small f-number that is capable of achieving high performance, as well as an imaging device equipped with this imaging lens.

[0008] This problem is solved with an imaging lens having the features of claim 1 and with an imaging lens having the features of claim 2.

[0009] A first imaging lens of the present invention consists, in order starting from the object side, essentially of a first lens with a negative refractive power, a second lens with a positive refractive power, a third lens with a positive refractive power, a fourth lens with a negative refractive power, a fifth lens with a positive refractive power, a sixth lens with a positive refractive power and a seventh lens with a negative refractive power, wherein The following conditional formulas must be fulfilled: f12 / f<−3.2 νd7<55 40<νd3 where, f12 is the combined focal length of the first lens and the second lens, f is the focal length of the entire system, vd7 is the Abbe number of the material of the seventh lens with respect to the d-line, and vd3 is the Abbe number of the material of the third lens with respect to the d-line.

[0010] A second imaging lens of the present invention consists, in order starting from the object side, essentially of a first lens with a negative refractive power, a second lens with a positive refractive power, a third lens with a positive refractive power, a fourth lens with a negative refractive power, a fifth lens with a positive refractive power, a sixth lens with a positive refractive power and a seventh lens with a negative refractive power, wherein The following conditional formulas must be fulfilled: f12 / f<−3.2 D4 / f<0.39 where, f12 is the combined focal length of the first lens and the second lens, f is the focal length of the entire system, and D4 is the air gap between the second lens and the third lens.

[0011] It should be noted that the above expression “consists essentially of” means that, in addition to the lenses listed as constituent elements, the imaging lens according to the invention may also include lenses that have practically no refractive power, optical elements other than lenses such as an aperture and a cover glass, and mechanical components such as lens flanges, a lens tube, a camera shake correction mechanism, etc.

[0012] In the present invention, surface shapes of lenses, such as a convex surface, a concave surface, a planar (flat) surface, biconcave, meniscus-shaped, biconvex, planoconvex, planocovave, and the like, and the sign of the refractive powers of lenses, such as positive or negative, in the paraxial (near-axis) region, are further considered if aspherical surfaces are included therein, unless otherwise specified. Furthermore, in the present invention, the sign of the radius of curvature is positive if a surface shape is convex on the object side and negative if the surface shape is convex on the image side. The expression "the center of the lens surface has a positive refractive power" means that a value of a paraxial radius of curvature is such that the lens surface forms a convex surface.Furthermore, the expression "the center of the lens surface has a negative refractive power" is meant to indicate that a value of a paraxial radius of curvature is such that the lens surface forms a concave surface.

[0013] In the first and second imaging lenses of the present invention described above, it is advantageous if the following condition formulas (8) and (13) to (23) are satisfied. It should be noted that preferably the imaging lens can have a configuration in which (exactly) any one of the following condition formulas (8) and (13) to (23) is satisfied, or a configuration in which any combination of two or more of the condition formulas is satisfied. −5.0<(R14+R15) / (R14−R15)<−0.01 25<νd5 0.5 <f3 / f<10 0.5 <f2 / f<7 f1 / f<−0.25 0.3 <f123 / f<15 0.5 <f234 / f<18 0.5 <f12345 / f<10 0.4 <f2345 / f<10 0.1 <f3456 / f<5,0 −4.0<(R8+R9) / (R8−R9)<4.0 -3 <f / f45<3 where, f is the focal length of the entire system, f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, f45 is the combined focal length of the fourth and fifth lenses. f123 is the combined focal length of the first lens, the second lens and the third lens, f234 is the combined focal length of the second lens, the third lens and the fourth lens, f345 is the combined focal length of the third lens, the fourth lens and the fifth lens, f2345 is the combined focal length of the second lens, the third lens, the fourth lens and the fifth lens. f3456 is the combined focal length of the third lens, the fourth lens, the fifth lens and the sixth lens. f12345 is the combined focal length of the first lens, the second lens, the third lens, the fourth lens and the fifth lens. vd5 is the Abbe number of the material of the fifth lens with respect to the d-line, R8 is the radius of curvature of the object-side surface of the fourth lens, R9 is the radius of curvature of the image-side surface of the fourth lens, R14 is the radius of curvature of the object-side surface of the seventh lens, and R15 is the radius of curvature of the image-side surface of the seventh lens.

[0014] An imaging device according to the invention is equipped with at least one of the first to second imaging lenses according to the invention described above.

[0015] According to the first imaging lens of the present invention, a refractive power arrangement and the like are suitably adjusted in the lens system consisting of seven lenses, and conditions (1) to (3) are fulfilled. This results in a compact imaging lens with a small f-value that is capable of achieving favorable optical performance.

[0016] According to the second imaging lens of the present invention, a refractive power arrangement and the like are suitably adjusted in the lens system consisting of seven lenses, and condition formulas (1) and (4) are fulfilled. This results in a compact imaging lens with a small f-value that is capable of achieving favorable optical performance. According to the imaging device of the present invention, the imaging device is equipped with the imaging lens of the present invention. This makes it possible to configure the imaging device with a small size in order to carry out photography even under poor lighting conditions and to obtain favorable images with high resolution, whereby various aberrations are corrected. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a view illustrating a lens configuration and optical paths of an imaging lens according to an embodiment of the present invention. Fig. Figure 2 is a view to illustrate the surface shape and the like of the second lens. Fig. Figure 3 is a cross-sectional view illustrating the lens configuration of an imaging lens of Example 1 of the present invention. Fig. Figure 4 is a cross-sectional view illustrating the lens configuration of an imaging lens of Example 2 of the present invention. Fig. Figure 5 is a cross-sectional view illustrating the lens configuration of an imaging lens of Example 3 of the present invention. Fig. Figure 6 is a cross-sectional view illustrating the lens configuration of an imaging lens of Example 4 of the present invention. Fig. Figure 7 is a cross-sectional view illustrating the lens configuration of an imaging lens of Example 5 of the present invention. Fig. Figure 8 is a cross-sectional view illustrating the lens configuration of an imaging lens of Example 6 of the present invention. Fig. Figure 9 is a cross-sectional view illustrating the lens configuration of an imaging lens of Example 7 of the present invention. Fig. Figure 10 is a cross-sectional view illustrating the lens configuration of an imaging lens of Example 8 of the present invention. Fig. Figure 11 is a cross-sectional view illustrating the lens configuration of an imaging lens of Example 9 of the present invention. Fig. Figure 12 is a cross-sectional view illustrating the lens configuration of an imaging lens of Example 10 of the present invention. Fig. Figure 13 is a cross-sectional view illustrating the lens configuration of an imaging lens of Example 11 of the present invention. Fig. Figure 14 is a cross-sectional view illustrating the lens configuration of an imaging lens of Example 12 of the present invention. Fig. Figure 15 is a cross-sectional view illustrating the lens configuration of an imaging lens of Example 13 of the present invention. Fig. Figure 16 is a cross-sectional view illustrating the lens configuration of an imaging lens of Example 14 of the present invention. Fig. Figure 17 is a cross-sectional view illustrating the lens configuration of an imaging lens of Example 15 of the present invention. Fig. Figure 18 is a cross-sectional view illustrating the lens configuration of an imaging lens of Example 16 of the present invention. Fig. Figure 19 is a cross-sectional view illustrating the lens configuration of an imaging lens of Example 17 of the present invention. Fig. Figure 20 is a cross-sectional view illustrating the lens configuration of an imaging lens of Example 18 of the present invention. Fig. Figure 21 is a cross-sectional view illustrating the lens configuration of an imaging lens of Example 19 of the present invention. Fig. Figure 22 is a cross-sectional view illustrating the lens configuration of an imaging lens of Example 20 of the present invention. Fig. Figure 23 is a cross-sectional view illustrating the lens configuration of an imaging lens of Example 21 of the present invention. Fig. Figure 24 is a cross-sectional view illustrating the lens configuration of an imaging lens of Example 22 of the present invention. Fig. Figure 25 is a cross-sectional view illustrating the lens configuration of an imaging lens of Example 23 of the present invention. Fig. Figure 26 is a cross-sectional view illustrating the lens configuration of an imaging lens of Example 24 of the present invention. Fig. Figure 27 is a cross-sectional view illustrating the lens configuration of an imaging lens of Example 25 of the present invention. Fig. Figure 28 is a cross-sectional view illustrating the lens configuration of an imaging lens of Example 26 of the present invention. Fig. Figure 29 shows aberration diagrams of spherical aberration, astigmatism, distortion and longitudinal chromatic aberration of the imaging lens of Example 1 of the present invention. Fig. Figure 30 shows aberration diagrams of spherical aberration, astigmatism, distortion and longitudinal chromatic aberration of the imaging lens of Example 2 of the present invention. Fig. Figure 31 shows aberration diagrams of spherical aberration, astigmatism, distortion and longitudinal chromatic aberration of the imaging lens of Example 3 of the present invention. Fig. Figure 32 shows aberration diagrams of spherical aberration, astigmatism, distortion and longitudinal chromatic aberration of the imaging lens of Example 4 of the present invention. Fig. Figure 33 shows aberration diagrams of spherical aberration, astigmatism, distortion and longitudinal chromatic aberration of the imaging lens of Example 5 of the present invention. Fig. Figure 34 shows aberration diagrams of spherical aberration, astigmatism, distortion and Longitudinal chromatic aberration of the imaging lens of Example 6 of the present invention. Fig. Figure 35 shows aberration diagrams of spherical aberration, astigmatism, distortion and longitudinal chromatic aberration of the imaging lens of Example 7 of the present invention. Fig. Figure 36 shows aberration diagrams of spherical aberration, astigmatism, distortion and longitudinal chromatic aberration of the imaging lens of Example 8 of the present invention. Fig. Figure 37 shows aberration diagrams of spherical aberration, astigmatism, distortion and longitudinal chromatic aberration of the imaging lens of Example 9 of the present invention. Fig. Figure 38 shows aberration diagrams of spherical aberration, astigmatism, distortion and longitudinal chromatic aberration of the imaging lens of Example 10 of the present invention. Fig. Figure 39 shows aberration diagrams of spherical aberration, astigmatism, distortion and longitudinal chromatic aberration of the imaging lens of Example 11 of the present invention. Fig. Figure 40 shows aberration diagrams of spherical aberration, astigmatism, distortion and longitudinal chromatic aberration of the imaging lens of Example 12 of the present invention. Fig. Figure 41 shows aberration diagrams of spherical aberration, astigmatism, distortion and longitudinal chromatic aberration of the imaging lens of Example 13 of the present invention. Fig. Figure 42 shows aberration diagrams of spherical aberration, astigmatism, distortion and longitudinal chromatic aberration of the imaging lens of Example 14 of the present invention. Fig. Figure 43 shows aberration diagrams of spherical aberration, astigmatism, distortion and longitudinal chromatic aberration of the imaging lens of Example 15 of the present invention. Fig. Figure 44 shows aberration diagrams of spherical aberration, astigmatism, distortion and longitudinal chromatic aberration of the imaging lens of Example 16 of the present invention. Fig. Figure 45 shows aberration diagrams of spherical aberration, astigmatism, distortion and longitudinal chromatic aberration of the imaging lens of Example 17 of the present invention. Fig. Figure 46 shows aberration diagrams of spherical aberration, astigmatism, distortion and longitudinal chromatic aberration of the imaging lens of Example 18 of the present invention. Fig. Figure 47 shows aberration diagrams of spherical aberration, astigmatism, distortion and longitudinal chromatic aberration of the imaging lens of Example 19 of the present invention. Fig. Figure 48 shows aberration diagrams of spherical aberration, astigmatism, distortion and longitudinal chromatic aberration of the imaging lens of Example 20 of the present invention. Fig. Figure 49 shows aberration diagrams of spherical aberration, astigmatism, distortion and longitudinal chromatic aberration of the imaging lens of Example 21 of the present invention. Fig. Figure 50 shows aberration diagrams of spherical aberration, astigmatism, distortion and longitudinal chromatic aberration of the imaging lens of Example 22 of the present invention. Fig. Figure 51 shows aberration diagrams of spherical aberration, astigmatism, distortion and longitudinal chromatic aberration of the imaging lens of Example 23 of the present invention. Fig. Figure 52 shows aberration diagrams of spherical aberration, astigmatism, distortion and longitudinal chromatic aberration of the imaging lens of Example 24 of the present invention. Fig. Figure 53 shows aberration diagrams of spherical aberration, astigmatism, distortion and longitudinal chromatic aberration of the imaging lens of Example 25 of the present invention. Fig. Figure 54 shows aberration diagrams of spherical aberration, astigmatism, distortion and longitudinal chromatic aberration of the imaging lens of Example 26 of the present invention. Fig. Figure 55 is a view illustrating an arrangement of a vehicle-based imaging device according to the embodiment of the present invention. DESCRIPTION OF PREFERRED EXECUTION FORMS

[0017] The following section describes embodiments of the present invention in detail with reference to the accompanying drawings. [Types of imaging lenses]

[0018] First, the imaging lens according to the embodiment of the present invention is compared with regard to Fig. 1 described. Fig. Figure 1 is a view illustrating a lens configuration and optical paths of the imaging lens according to the embodiment of the present invention. It should be noted that the Fig. 1 Illustrated imaging lens 1 corresponds to an imaging lens of Example 1 of the present invention, which will be described later.

[0019] In Fig. 1 is the left side of the figure, the object side, and the right side is the image side. Fig. Figure 1 additionally illustrates axial rays 2 from an object point at infinite distance and off-axis rays 3, 4 at full viewing angle 2ω. Furthermore, it illustrates Fig. 1. An image sensor 5, which is arranged on the image surface Sim encompassing the pixel Pim of the imaging lens 1, is considered when the imaging lens 1 is attached to an imaging device. The image sensor 5 converts an optical image formed by the imaging lens 1 into an electrical signal. For example, a CCD image sensor, a CMOS image sensor, or the like can be used as the image sensor.

[0020] When the imaging lens 1 is attached to the imaging device, it is preferably to provide a cover glass, a low-pass filter, an infrared cut-off filter or the like, according to the configuration of a camera to which the lens is attached. Fig. Figure 1 illustrates an example in which a plane-parallel optical element PP, which is intended to represent such components, is provided between the lens furthest from the image side and the image sensor 5 (the image surface Sim).

[0021] First, the configuration of the first embodiment of the present invention is described. The imaging lens according to the first embodiment of the present invention comprises, in order starting from the object side, a first lens L1 with a negative refractive power, a second lens L2 with a positive refractive power, a third lens L3 with a positive refractive power, a fourth lens L4 with a negative refractive power, a fifth lens L5 with a positive refractive power, and a sixth lens with a positive refractive power. In the Fig. In the illustrated example 1, an aperture diaphragm St is arranged between the third lens L3 and the fourth lens L4. It should be noted that the in Fig. 1 The illustrated aperture diaphragm St does not necessarily represent its size or shape, but its position on the optical axis Z.

[0022] Furthermore, the imaging lens of the first embodiment is configured to satisfy the following condition formulas (1) to (3): f12 / f<−3.2 νd7<55 40<νd3 where, f12 is the combined focal length of the first lens L1 and the second lens L2, f is the focal length of the entire system, vd7 is the Abbe number of the material of the seventh lens L7 with respect to the d-line, and vd3 is the Abbe number of the material of the third lens L3 with respect to the d-line.

[0023] The configuration of the second embodiment of the present invention is described below. The imaging lens according to the second embodiment of the present invention consists, in order starting from the object side, of a first lens L1 with a negative refractive power, a second lens L2 with a positive refractive power, a third lens L3 with a positive refractive power, a fourth lens L4 with a negative refractive power, a fifth lens L5 with a positive refractive power, a sixth lens L6 with a positive refractive power, and a seventh lens L7 with a negative refractive power, in the same manner as the imaging lens according to the first embodiment. In the Fig. In the illustrated example 1, an aperture diaphragm St is arranged between the third lens L3 and the fourth lens L4.

[0024] Furthermore, the imaging lens of the second embodiment is configured according to the following formulas. (1) and (4) to fulfill: f12 / f<−3.2 D4 / f<0.39 where, f12 is the combined focal length of the first lens L1 and the second lens L2, f is the focal length of the entire system, and D4 is the air gap between the second lens L2 and the third lens L3.

[0025] Each of the imaging lenses of the first to second embodiments consists, in order starting from the object side, of a first lens L1 with a negative refractive power, a second lens L2 with a positive refractive power, a third lens L3 with a positive refractive power, a fourth lens L4 with a negative refractive power, a fifth lens L5 with a positive refractive power, a sixth lens L6 with a positive refractive power, and a seventh lens L7 with a negative refractive power. Such a configuration simplifies the manufacture of lenses with favorable resolution characteristics that correct various aberrations.

[0026] By configuring the first lens L1, which is the lens furthest from the object, to have a negative refractive power, a lens system can still achieve a large viewing angle, and ensuring back focus and reducing the size of the lens system in the radial direction is simplified.

[0027] By configuring the second lens L2 and the third lens L3 to have positive refractive powers, and by configuring the fifth lens L5 and the sixth lens L6 to have positive refractive powers, each section within the lens system that carries a positive refractive power can be formed by two positive lenses. Such a configuration simplifies the correction of spherical aberration and astigmatism.

[0028] In the imaging lens of the first embodiment, the following can be achieved by fulfilling the condition formula. (1) A decrease in the absolute value of the combined focal length of the first lens L1 and the second lens L2 is suppressed as a positive value within the defined upper limit. This simplifies the suppression of the increase in the negative refractive power of the first lens L1 or the increase in the positive refractive power of the second lens L2. Similarly, the suppression of astigmatism is simplified.

[0029] By fulfilling the upper limit defined by condition formula (2), the correction of lateral chromatic aberration is simplified and the achievement of favorable resolution characteristics is also simplified.

[0030] By fulfilling the lower limit defined by condition formula (3), the correction of longitudinal chromatic aberration is simplified and the achievement of favorable resolution characteristics is also simplified.

[0031] In the imaging lens of the second embodiment, the following can be achieved by fulfilling the condition formula. (1) The defined upper limit suppresses the decrease in the combined focal length of the first lens L1 and the second lens L2. This simplifies the suppression of the increase in the negative refractive power of the first lens L1 or the increase in the positive refractive power of the second lens L2. Similarly, the suppression of astigmatism is simplified.

[0032] By satisfying the upper limit defined by condition formula (4), the air gap between the second lens L2 and the third lens L3 is avoided, and the reduction of the size of the lens system is simplified.

[0033] In the imaging lens of the third embodiment, the condition formula is fulfilled. (2) The defined upper limit simplifies the correction of lateral chromatic aberration and also simplifies the achievement of favorable resolution characteristics.

[0034] It should be noted that the imaging lens according to the first embodiment can have the configuration of the imaging lens of the second embodiment or the configuration of the imaging lens of the second embodiment. Furthermore, the imaging lens according to the second embodiment can have the configuration of the imaging lens of the first embodiment or the configuration of the imaging lens of the first embodiment.

[0035] Furthermore, the imaging lens according to the first embodiment can have part of the configuration of the imaging lens according to the second embodiment. The imaging lens according to the second embodiment can have part of the configuration of the imaging lens according to the first embodiment or can have part of the configuration of the imaging lens according to the third embodiment.

[0036] Next, preferred configurations of the imaging lens according to the aforementioned first and second embodiments of the present invention and their advantageous effects are described. It should be noted that the imaging lens may preferably have exactly one of the following configurations or any combination of two or more of the configurations. 1.8 <f345 / f f1 / f2 < −0.42 −5.0<(R14+R15) / (R14−R15)<−0.01 −0.8<(R5+R6) / (R5−R6) 1.25 <f5 / f 0.5<(R10+R11) / (R10−R11) (R12+R13) / (R12−R13)<1.0 25<νd5 0.5 <f3 / f<10 0.5 <f2 / f<7 f1 / f<−0.25 0.3 <f123 / f<15 0.5 <f234 / f<18 0.5 <f12345 / f<10 0.4 <f2345 / f<10 0.1 <f3456 / f<5,0 −4.0<(R8+R9) / (R8−R9)<4.0 -3 <f / f45<3 where, f is the focal length of the entire system, f1 is the focal length of the first lens L1, f2 is the focal length of the second lens L2, f3 is the focal length of the third lens L3, f5 is the focal length of the fifth lens L5, f45 is the combined focal length of the fourth lens L4 and the fifth lens L5, f123 is the combined focal length of the first lens L1, the second lens L2 and the third lens L3, f234 is the combined focal length of the second lens L2, the third lens L3 and the fourth lens L4, f345 is the combined focal length of the third lens L3, the fourth lens L4 and the fifth lens L5, f2345 is the combined focal length of the second lens L2, the third lens L3, the fourth lens L4 and the fifth lens L5, f3456 is the combined focal length of the third lens L3, the fourth lens L4, the fifth lens L5 and the sixth lens L6, f12345 is the combined focal length of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4 and the fifth lens L5, vd5 is the Abbe number of the material of the fifth lens L5 with respect to the d-line, R5 is the radius of curvature of the object-side surface of the third lens L3, R6 is the radius of curvature of the image-side surface of the third lens L3, R8 is the radius of curvature of the object-side surface of the fourth lens L4, R9 is the radius of curvature of the image-side surface of the fourth lens L4, R10 is the radius of curvature of the object-side surface of the fifth lens L5, R11 is the radius of curvature of the image-side surface of the fifth lens L5, R12 is the radius of curvature of the object-side surface of the sixth lens L6, R13 is the radius of curvature of the image-side surface of the sixth lens L6, R14 is the radius of curvature of the object-side surface of the seventh lens L7, and R15 is the radius of curvature of the image-side surface of the seventh lens L7.

[0037] By fulfilling the lower limit defined by condition formula (6), it is simplified to avoid the combined focal length of the third lens L3 to the fifth lens L5 decreasing as a positive value. This simplifies ensuring back focus or correcting astigmatism.

[0038] By satisfying the upper limit defined by condition formula (7), reducing the negative refractive power of the first lens L1, i.e., increasing the absolute value of the focal length of the first lens L1, is simplified. Furthermore, the correction of distortion is simplified. Alternatively, suppressing an excessive decrease in the positive refractive power of the second lens L2, i.e., decreasing the absolute value of the focal length of the second lens L2, is simplified, and the correction of spherical aberration and astigmatism is also simplified.

[0039] By satisfying the upper limit defined by condition formula (8), configuring the radius of curvature of the object-side surface such that it is smaller than the radius of curvature of the image-side surface is simplified, while the object-side surface of the seventh lens L7 is concave. This simplifies the correction of astigmatism or the correction of lateral chromatic aberration.

[0040] By satisfying the lower limit defined by condition formula (8), differentiating (delimiting) the radius of curvature of the object-side surface of the seventh lens L7 from the radius of curvature of the image-side surface of the seventh lens L7 and increasing the refractive power of the seventh lens L7 is simplified, while the seventh lens L7 has a meniscus shape with a convex surface facing the image side. Furthermore, the correction of coma aberration is simplified.

[0041] By satisfying the lower limit defined by condition formula (9), suppressing the increase in the absolute value of the radius of curvature of the image-side surface is simplified, and the correction of coma aberration is also simplified, while the third lens L3 is a biconvex lens.

[0042] By fulfilling the lower limit defined by condition formula (10), suppressing an excessive increase in the positive refractive power of the fifth lens L5 is simplified. This simplifies ensuring back focus or reducing the error sensitivity of the fifth lens L5 with respect to eccentricity.

[0043] By satisfying the lower limit defined by condition formula (11), suppressing the decrease in the absolute value of the radius of curvature of the object-side surface of the fifth lens L5 is simplified, or configuring the object-side surface of the fifth lens L5 as concave is simplified while the object-side surface of the fifth lens L5 is convex. Furthermore, the correction of spherical aberration and coma aberration is simplified.

[0044] By satisfying the upper limit defined by condition formula (12), the configuration of the sixth lens L6 as a biconvex lens is simplified, and the correction of spherical aberration is also simplified.

[0045] By satisfying the lower limit defined by condition formula (13), the correction of longitudinal chromatic aberration is simplified.

[0046] By fulfilling the upper limit defined by condition formula (14), increasing the refractive power of the third lens L3 is simplified, and the correction of astigmatism and spherical aberration is also simplified.

[0047] By fulfilling the lower limit defined by condition formula (14), reducing the refractive power of the third lens L3 is simplified, and reducing the error sensitivity of the third lens L3 with respect to eccentricity is simplified.

[0048] By fulfilling the upper limit defined by condition formula (15), increasing the refractive power of the second lens L2 is simplified, and the correction of astigmatism, spherical aberration, and distortion is simplified.

[0049] By fulfilling the lower limit defined by condition formula (15), reducing the refractive power of the second lens L2 is simplified, and reducing the error sensitivity of the second lens L2 with respect to eccentricity is simplified.

[0050] By fulfilling the upper limit defined by condition formula (16), the reduction of the refractive power of the first lens L1 is simplified, resulting in a simplified correction of astigmatism.

[0051] By satisfying the upper limit defined by condition formula (17), the suppression of the increase in the combined focal length of the first lens L1 to the third lens L3 is simplified as a positive value, and the suppression of astigmatism and spherical aberration is also simplified.

[0052] By satisfying the lower limit defined by condition formula (17), suppressing the decrease of the combined focal length of the first lens L1 to the third lens L3 as a positive value is simplified, and achieving a large angle of view is also simplified.

[0053] By satisfying the upper limit defined by condition formula (18), the suppression of the increase in the combined focal length of the second lens L2 to the fourth lens L4 is simplified as a positive value, resulting in a simplified correction of astigmatism.

[0054] By satisfying the lower limit defined by condition formula (18), suppressing the decrease of the combined focal length of the second lens L2 to fourth lens L4 as a positive value is simplified, ensuring back focus is simplified, or correcting spherical aberration is simplified.

[0055] By satisfying the upper limit defined by condition formula (19), suppressing an excessive increase in the combined focal length of the first lens L1 to the fifth lens L5 is simplified as a positive value. This simplifies reducing the size of the lens system or correcting spherical aberration.

[0056] By fulfilling the lower limit defined by condition formula (19), the suppression of an excessive decrease in the combined focal length of the first lens L1 to fifth lens L5 as a positive value is simplified, and ensuring the back focus is simplified.

[0057] By satisfying the upper limit defined by condition formula (20), suppressing an excessive increase in the combined focal length of the second lens L2 to the fifth lens L5 is simplified as a positive value. This simplifies shortening the overall length of the lens system or reducing lateral chromatic aberration.

[0058] By fulfilling the lower limit defined by condition formula (20), suppressing an excessive decrease in the combined focal length of the second lens L2 to the fifth lens L5 as a positive value is simplified. This simplifies the correction of longitudinal chromatic aberration or the ensuring of a long back focus.

[0059] By satisfying the upper limit defined by condition formula (21), the suppression of an excessive increase in the combined focal length of the third lens L3 to sixth lens L6 as a positive value is simplified, and the correction of spherical aberration, astigmatism, or lateral chromatic aberration is simplified.

[0060] By satisfying the lower limit defined by condition formula (21), the suppression of an excessive decrease in the combined focal length of the third lens L3 to the sixth lens L6 is simplified as a positive value. This simplifies achieving a wide angle of view or correcting longitudinal chromatic aberration.

[0061] By fulfilling the upper limit defined by condition formula (22), differentiating the radius of curvature of the object-side surface of the fourth lens L4 from the radius of curvature of the image-side surface of the fourth lens L4 and increasing the refractive power of the fourth lens L4 is simplified, while the fourth lens L4 has a meniscus shape with a concave surface facing the image side. Furthermore, the correction of longitudinal chromatic aberration or the correction of coma aberration and astigmatism is simplified.

[0062] By fulfilling the lower limit defined by condition formula (22), differentiating the radius of curvature of the object-side surface of the fourth lens L4 from the radius of curvature of the image-side surface of the fourth lens L4 and increasing the refractive power of the fourth lens L4 is simplified, while the fourth lens L4 has a meniscus shape with a concave surface facing the image side. Furthermore, the correction of longitudinal chromatic aberration or spherical aberration is simplified.

[0063] By satisfying the upper limit defined by condition formula (23), suppressing an excessive decrease in the combined focal length of the fourth lens L4 and the fifth lens L5 as a positive value is simplified. This simplifies increasing the negative refractive power of the fourth lens L4 and simplifies the correction of longitudinal chromatic aberration.

[0064] By satisfying the lower limit defined by condition formula (23), the suppression of an excessive decrease in the combined focal length of the fourth lens L4 and the fifth lens L5 as a negative value, which results in an increase in the positive refractive power of the fifth lens L5, is simplified. This simplifies the correction of spherical aberration or the reduction of the overall length of the lens system.

[0065] It should be noted that it is still preferred to satisfy the following conditional formulas, in which upper or lower bounds have been added to or the upper or lower bounds in the above conditional formulas have been modified, in order to enhance the advantageous effects described above. Furthermore, the conditional formulas described below may also be preferably satisfied, each of which is configured by combining a modified value of the lower bound and a modified value of the upper bound. Preferred modifications of the conditional formulas are described below as examples; however, the modifications of the conditional formulas are not limited to those listed below, and the modified values ​​described below may be combined.

[0066] It is preferred if the upper limit defined by condition formula (1) is -3.3 and particularly preferred if it is -3.5.

[0067] It is preferred if condition formula (1) is provided with a lower limit, and if the lower limit is -50. This simplifies the suppression of an excessive decrease in the negative refractive power of the first lens L1. Furthermore, it simplifies achieving a large viewing angle or reducing the size of the lens system in the radial direction. Particularly preferably, the lower limit defined by condition formula (1) is -40, more preferably -35, and even more preferably -30. As described above, it is particularly preferred if the following condition formulas (1-1) to (1-5) are satisfied: f12 / f<−3.3 f12 / f<−3.5 -50 <f12 / f<−3,2 -40 <f12 / f<−3,3 -35 <f12 / f<−3,3

[0068] It is preferred if the upper limit defined by condition formula (2) is 50, particularly preferred 45, further preferred 42 and even more preferred 35.

[0069] It is preferred if condition formula (2) is provided with a lower bound and if the lower bound is 15. This simplifies the suppression of the cost of the material for the seventh lens L7. It is particularly preferred if the lower bound defined by condition formula (2) is 17. As described above, it is preferred if, for example, the following condition formulas (2-1) to (2-5) are satisfied: 15<νd7<55 νd7<50 νd7<45 νd7<42 15<νd7<45

[0070] It is preferred if condition formula (3) is provided with an upper limit and if the upper limit is 85. This simplifies the reduction of the cost of the material for the third lens L3. It is particularly preferred if the upper limit defined by condition formula (3) is 70, further preferably 68, and even more preferably 65.

[0071] It is preferred if the lower limit defined by condition formula (3) is 45, particularly preferably 50, and even more preferably 52. ​​As described above, it is preferred if, for example, the following condition formulas (3-1) to (3-6) are satisfied: 40<νd3<85 40<νd3<70 45<νd3 50<νd3 52<νd3 50<νd3<68

[0072] It is preferred if the upper limit defined by condition formula (4) is 0.35, particularly preferred 0.3, further preferred 0.25, further preferred 0.2, further preferred 0.15 and even more preferred 0.1.

[0073] It is preferred if the lower limit defined by condition formula (4) is 0.01, particularly preferably 0.02, further preferably 0.03, and even more preferably 0.04. As described above, it is preferred if the following condition formulas (4-1) to (4-10) are satisfied: 0.0 <D4 / f<0,35 0.0 <D4 / f<0,3 0.0 <D4 / f<0,25 0.0 <D4 / f<0,2 0.0 <D4 / f<0,15 0.0 <D4 / f<0,1 0.01 <D4 / f<0,35 0.02 <D4 / f<0,3 0.03 <D4 / f<0,25 0.04 <D4 / f<0,2

[0074] It is preferred if condition formula (6) is provided with an upper limit and if the upper limit is 15. This simplifies the reduction of the overall length. It is preferred if the upper limit defined by condition formula (6) is 10, particularly preferably 8, and further preferably 7.

[0075] It is preferred if the lower limit defined by condition formula (6) is 1.85, particularly preferably 1.9, and further preferably 1.95. As described above, it is preferred if, for example, the following condition formulas (6-1) to (6-5) are satisfied: 1.8 <f345 / f<15 1.8 <f345 / f<10 1.8 <f345 / f<8 1.9 <f345 / f<10 1.85 <f345 / f<7

[0076] It is preferred if the upper limit defined by condition formula (7) is -0.43 and particularly preferred if it is -0.44.

[0077] It is preferred if condition formula (7) is provided with a lower limit and if the lower limit is -5. This simplifies suppressing a decrease in the negative refractive power of the first lens L1, i.e., reducing the absolute value of the focal length of the first lens L1, and simplifies achieving a large angle of view. It is preferred if the condition formula (7) is provided with a lower limit of -5. (7) defined lower limit -3 is, most preferably -2, more preferably -1, more preferably -0.8 and even more preferably -0.7. As described above, it is preferred if, for example, the following condition formulas (7-1) to (7-6) are satisfied: -5 <f1 / f2<−0,43 -3 <f1 / f2<−0,42 -2 <f1 / f2<−0,42 -1 <f1 / f2<−0,42 -0.8 <f1 / f2<−0,42 -0.7 <f1 / f2<−0,42

[0078] It is preferred if the upper limit defined by condition formula (8) is -0.2, particularly preferred if -0.3, further preferred if -0.4 and even more preferred if -0.5.

[0079] It is preferred if the lower limit defined by condition formula (8) is -2.1, particularly preferred -2.0, further preferred -1.9 and even more preferred -1.8. As described above, it is preferred if, for example, the following condition formulas (8-1) to (8-10) are satisfied: −4.0<(R14+R15) / (R14−R15)<−0.01 −3.0<(R14+R15) / (R14−R15)<−0.01 −3.0<(R14+R15) / (R14−R15)<−0.2 −2.1<(R14+R15) / (R14−R15)<−0.01 −2.0<(R14+R15) / (R14−R15)<−0.2 −1.9<(R14+R15) / (R14−R15)<−0.2 −2.0<(R14+R15) / (R14−R15)<−0.3 −1.8<(R14+R15) / (R14−R15)<−0.3 −2.2<(R14+R15) / (R14−R15)<−0.4 −2.1<(R14+R15) / (R14−R15)<−0.4

[0080] It is preferred if an upper limit is defined for condition formula (9) and if the upper limit is 3.0. This simplifies the suppression of a decrease in the radius of curvature of the object-side surface of the third lens L3, which is concave, resulting in simplified correction of spherical aberration. It is particularly preferred if the upper limit defined by condition formula (9) is 2.0, particularly preferably 1.0, further preferably 0.95, and even more preferably 0.9.

[0081] It is preferred if the lower limit defined by condition formula (9) is -0.75, particularly preferred if it is -0.7, and further preferred if it is -0.68. As described above, it is preferred if, for example, condition formulas (9-1) to (9-7) are satisfied: −0.8<(R5+R6) / (R5−R6)<2.0 −0.8<(R5+R6) / (R5−R6)<1.0 −0.8<(R5+R6) / (R5−R6)<0.95 −0.8<(R5+R6) / (R5−R6)<0.9 −0.75<(R5+R6) / (R5−R6)<1.0 −0.7<(R5+R6) / (R5−R6)<1.0 −0.68<(R5+R6) / (R5−R6)<2.0

[0082] It is preferred if condition formula (10) is provided with an upper limit and if the upper limit is 10. This simplifies increasing the positive refractive power of the fifth lens L5, which results in a simplified reduction of the angles at which peripheral light rays reach the image sensor. It is particularly preferred if the upper limit defined by condition formula (10) is 8.0, further preferably 5.0, further preferably 4.0, and even more preferably 3.5.

[0083] It is preferred if the lower limit defined by condition formula (10) is 1.27, particularly preferably 1.28, and further preferably 1.3. As described above, it is preferred if, for example, the following condition formulas (10-1) to (10-7) are satisfied: 1.25 <f5 / f<10 1.25 <f5 / f<8,0 1.25 <f5 / f<5,0 1.27 <f5 / f<4,0 1.25 <f5 / f<3,5 1.28 <f5 / f<5,0 1.3 <f5 / f<5,0

[0084] It is preferred if condition formula (11) is provided with an upper limit and if the upper limit is 5.0. This simplifies increasing the refractive power of the fifth lens L5, resulting in a simplified reduction of the angles at which principal rays of off-axis rays reach the image sensor or in a simplified correction of spherical aberration. It is particularly preferred if the upper limit defined by condition formula (11) is 4.0, further preferably 3.0, further preferably 2.5, and even more preferably 2.3.

[0085] It is preferred if the lower limit defined by condition formula (11) is 0.6, particularly preferably 0.65, further preferably 0.7, and even more preferably 0.8. As described above, it is preferred if, for example, the following condition formulas (11-1) to (11-8) are satisfied: 0.65<(R10+R11) / (R10−R11) 0.5<(R10+R11) / (R10−R11)<5.0 0.6<(R10+R11) / (R10−R11)<4.0 0.7<(R10+R11) / (R10−R11)<3.0 0.5<(R10+R11) / (R10−R11)<2.5 0.5<(R10+R11) / (R10−R11)<2.3 0.8<(R10+R11) / (R10−R11)<4.0 0.65<(R10+R11) / (R10−R11)<3.0

[0086] It is preferred if the upper limit defined by condition formula (12) is 0.7, particularly preferred 0.5, further preferred 0.3, further preferred 0.2 and even more preferred 0.1.

[0087] It is preferred if condition formula (12) is provided with a lower limit and if the lower limit is -1.0. This simplifies the suppression of a decrease in the radius of curvature of the object-side surface, resulting in simplified correction of field curvature and coma aberration, while the sixth lens L6 is a biconvex lens. It is particularly preferred if the lower limit defined by condition formula (12) is -0.9, further preferably -0.8, further preferably -0.7, and even more preferably -0.6. As described above, it is preferred if, for example, the following condition formulas (12-1) to (12-7) are satisfied: −1.0<(R12+R13) / (R12−R13)<1.0 (R12+R13) / (R12−R13)<0.5 −0.9<(R12+R13) / (R12−R13)<0.3 −0.8<(R12+R13) / (R12−R13)<0.2 −0.7<(R12+R13) / (R12−R13)<0.5 −0.6<(R12+R13) / (R12−R13)<0.7 −0.8<(R12+R13) / (R12−R13)<0.3

[0088] It is preferred if condition formula (13) is provided with an upper limit and if the upper limit is 85. This simplifies the reduction of the cost of the material for the fifth lens L5. It is particularly preferred if the upper limit defined by condition formula (13) is 70, more preferably 68, and still more preferably 65.

[0089] It is preferred if the lower limit defined by condition formula (13) is 28, particularly preferably 30, and even more preferably 35. As described above, it is preferred if, for example, the following condition formulas (13-1) to (13-5) are satisfied: 30<νd5 25<νd5<85 25<νd5<70 28<νd5<68 30<νd5<65

[0090] It is preferred if the upper limit defined by condition formula (14) is 8, particularly preferred 7, further preferred 6, further preferred 5 and even more preferred 4.5.

[0091] It is preferred if the lower limit defined by condition formula (14) is 0.6, particularly preferably 0.8, further preferably 1.0, and even more preferably 1.2. As described above, it is preferred if, for example, the following condition formulas (14-1) to (14-7) are satisfied: 0.5 <f3 / f<7 0.8 <f3 / f<10 0.5 <f3 / f<10 0.6 <f3 / f<8 0.8 <f3 / f<7 1.0 <f3 / f<6 1.2 <f3 / f<5

[0092] It is preferred if the upper limit defined by condition formula (15) is 6.5, particularly preferred 6, further preferred 5 and even more preferred 4.5.

[0093] It is preferred if the lower limit defined by condition formula (15) is 0.7, particularly preferably 0.9, further preferably 1.2, further preferably 1.5, and even more preferably 1.7. As described above, it is preferred if, for example, the following condition formulas (15-1) to (15-7) are satisfied: 0.5 <f2 / f<6 0.9 <f2 / f<7 0.7 <f2 / f<6,5 0.9 <f2 / f<6 1.2 <f2 / f<5 1.5 <f2 / f<4,5 1.7 <f2 / f<7

[0094] It is preferred if the upper limit defined by condition formula (16) is -0.4, particularly preferred if -0.6, further preferred if -0.8 and even more preferred if -1.0.

[0095] It is preferred if condition formula (16) is provided with a lower limit, and if the lower limit is -10. This simplifies increasing the refractive power of the first lens L1, resulting in a simplified achievement of a wide viewing angle. It is preferred if the lower limit defined by condition formula (16) is -8, more preferably -7, more preferably -5, more preferably -3, and still more preferably -2. As described above, it is preferred if, for example, the following condition formulas (16-1) to (16-7) are satisfied: -10 <f1 / f<−0,25 -8 <f1 / f<−0,25 -8 <f1 / f<−0,4 -7 <f1 / f<−0,4 -5 <f1 / f<−0,6 -3 <f1 / f<−0,8 -2 <f1 / f<−1,0

[0096] It is preferred if the upper limit defined by condition formula (17) is 10, particularly preferably 8, further preferably 6 and even more preferably 5.

[0097] It is preferred if the lower limit defined by condition formula (17) is 0.5, particularly preferably 0.8, further preferably 1.0, and even more preferably 1.1. As described above, it is preferred if, for example, the following condition formulas (17-1) to (17-8) are satisfied: 0.3 <f123 / f<15 0.5 <f123 / f<10 0.8 <f123 / f<8 1.0 <f123 / f<6 1.1 <f123 / f<5 0.3 <f123 / f<10 0.5 <f123 / f<6 0.8 <f123 / f<8

[0098] It is preferred if the upper limit defined by condition formula (18) is 15, particularly preferred 10, further preferred 8, further preferred 7 and even more preferred 6.

[0099] It is preferred if the lower limit defined by condition formula (18) is 0.8, particularly preferably 1.0, and even more preferably 1.2. As described above, it is preferred if, for example, the following condition formulas (18-1) to (18-7) are satisfied: 0.5 <f234 / f<10 0.8 <f234 / f<15 1.0 <f234 / f<8 1.2 <f234 / f<7 1.0 <f234 / f<6 0.8 <f234 / f<8 0.5 <f234 / f<6

[0100] It is preferred if the upper limit defined by condition formula (19) is 9, particularly preferred 8, further preferred 7, further preferred 6 and even more preferred 5.5.

[0101] It is preferred if the lower limit defined by condition formula (19) is 0.8, particularly preferably 1.0, further preferably 1.2, and even more preferably 1.5. As described above, it is preferred if, for example, the following condition formulas (19-1) to (19-8) are satisfied: 0.5 <f12345 / f<8 0.5 <f12345 / f<9 0.8 <f12345 / f<8 1.0 <f12345 / f<7 1.2 <f12345 / f<6 1.5 <f12345 / f<5,5 0.8 <f12345 / f<10 0.8 <f12345 / f<7

[0102] It is preferred if the upper limit defined by condition formula (20) is 8, particularly preferred 6, further preferred 5, further preferred 4 and even more preferred 3.

[0103] It is preferred if the lower limit defined by condition formula (20) is 0.6, particularly preferably 0.8, further preferably 1.0, and even more preferably 1.2. As described above, it is preferred if, for example, the following condition formulas (20-1) to (20-7) are satisfied: 0.6 <f2345 / f<8 0.8 <f2345 / f<6 1.0 <f2345 / f<5 1.2 <f2345 / f<4 1.0 <f2345 / f<3 0.4 <f2345 / f<6 0.8 <f2345 / f<8

[0104] It is preferred if the upper limit defined by condition formula (21) is 4.0, particularly preferred 3.0 and further preferred 2.0.

[0105] It is preferred if the lower limit defined by condition formula (21) is 0.3, particularly preferably 0.5, and further preferably 0.6. As described above, it is preferred if, for example, the following condition formulas (21-1) to (21-6) are satisfied: 0.3 <f3456 / f<4,0 0.5 <f3456 / f<3,0 0.6 <f3456 / f<2,0 0.3 <f3456 / f<5,0 0.1 <f3456 / f<2,0 0.3 <f3456 / f<3,0

[0106] It is preferred if the upper limit defined by condition formula (22) is 3.0, particularly preferred 2.0, further preferred 1.0 and even more preferred 0.9.

[0107] It is preferred if the lower limit defined by condition formula (22) is -3.5, particularly preferred -3.0, further preferred -2.5, and even more preferably -2.0. As described above, it is preferred if, for example, the following condition formulas (22-1) to (22-5) are satisfied: −3.5<(R8+R9) / (R8−R9)<3.0 −3.0<(R8+R9) / (R8−R9)<2.0 −2.5<(R8+R9) / (R8−R9)<1.0 −2.0<(R8+R9) / (R8−R9)<2.0 −3.0<(R8+R9) / (R8−R9)<3.0

[0108] It is preferred if the upper limit defined by condition formula (23) is 2, particularly preferably 1, further preferably 0.7, further preferably 0.5, further preferably 0.3 and even more preferably 0.2.

[0109] It is preferred if the lower limit defined by condition formula (23) is -2, particularly preferred -1, further preferred -0.7, further preferred -0.5 and even more preferred -0.3. As described above, it is preferred if, for example, the following condition formulas (23-1) to (23-6) are satisfied: -1 <f / f45<1 -0.7 <f / f45<0,7 -0.5 <f / f45<0,5 -0.3 <f / f45<1 -1 <f / f45<0,3 -0.5 <f / f45<0,3

[0110] The aperture diaphragm refers to a diaphragm that determines the f-number (Fno) of the lens system. It is preferred that the aperture diaphragm be located on the object side of the sixth lens L6. In this case, "the aperture diaphragm is located on the object side of the sixth lens L6" means that the center (the position on the optical axis) of the aperture diaphragm is located further towards the object side than the image-side surface of the sixth lens L6. By locating the aperture diaphragm on the object side of the sixth lens L6, reducing the aperture diameter of the first lens L1 is simplified, resulting in a simplified reduction of the lens diameter. For example, if the imaging lenses of the present embodiments are used in vehicle-based cameras, lens sections exposed to the outside of the vehicle must be small so as not to detract from the vehicle's appearance.By positioning the aperture diaphragm on the object side of the sixth lens L6, reducing the aperture diameter of the first lens L1 is simplified. This simplifies the reduction of the lens sections exposed to the outside of a vehicle. Furthermore, it simplifies reducing the angle of incidence of light rays reaching the image sensor, resulting in simplified shading suppression.

[0111] It is preferred if the aperture diaphragm is located on the object side of the fifth lens L5.

[0112] It is preferred that the aperture diaphragm be located on the object side of the image-side surface of the fourth lens L4. This simplifies the miniaturization of sections exposed to the outside of the lens system.

[0113] It is preferred if the aperture diaphragm is located on the image side of the second lens L2. This allows the diameters of the seventh lens L7 and the first lens L1 to be balanced, resulting in a simplified reduction of the overall lens diameter.

[0114] It is preferred if the aperture diaphragm is located on the image side of the third lens L3.

[0115] In order to miniaturize the sections exposed to the outside of the lens system and to reduce the diameters of the entire lens system in a well-balanced manner, it is preferred if the aperture diaphragm is arranged between the second lens L2 and the third lens L3, between the third lens L3 and the fourth lens L4, or between the fourth lens L4 and the fifth lens L5.

[0116] It is preferred if the first lens L1 has a convex surface facing the object. This simplifies the correction of distortion.

[0117] It is preferred if the first lens L1 has a meniscus shape with a convex surface facing the object. This simplifies the correction of distortion.

[0118] It is preferred if the second lens L2 is a lens having a convex surface facing the image side. This simplifies the correction of astigmatism.

[0119] It is preferred if the object-side surface of the second lens L2 is concave. This simplifies the correction of distortion. The object-side surface of the second lens L2 can also be convex. This simplifies the correction of astigmatism.

[0120] It is preferred if the object-side surface of the third lens L3 is convex. This simplifies the correction of astigmatism.

[0121] It is preferred if the image-side surface of the third lens L3 is convex. This simplifies the correction of spherical aberration.

[0122] It is preferred if the object-side surface of the fourth lens L4 is concave. This simplifies increasing the negative refractive power of the fourth lens L4, resulting in simplified correction of longitudinal chromatic aberration or astigmatism.

[0123] It is preferred if the image-side surface of the fourth lens L4 is concave. This simplifies increasing the negative refractive power of the fourth lens L4, resulting in simplified correction of longitudinal chromatic aberration or spherical aberration.

[0124] It is preferable if the object-side surface of the fifth lens L5 is concave. This simplifies the correction of astigmatism.

[0125] It is preferred if the image-side surface of the fifth lens L5 is convex or planar. This simplifies the correction of spherical aberration.

[0126] It is preferred if the object-side surface of the sixth lens L6 is convex. This simplifies the correction of spherical aberration.

[0127] It is preferred if the image-side surface of the sixth lens L6 is convex. This simplifies the correction of astigmatism.

[0128] It is preferred if the object-side surface of the seventh lens L7 is concave. This simplifies the correction of astigmatism.

[0129] It is preferred that the image-side surface of the seventh lens L7 be planar or convex. This simplifies the reduction of the angles at which the principal rays of the off-axis rays reach the image sensor. Alternatively, the image-side surface of the seventh lens L7 can be concave. This simplifies the correction of astigmatism.

[0130] It is preferred if the Abbe number of the material of the first lens L1 with respect to the d-line is greater than or equal to 30. This allows for favorable correction of longitudinal and lateral chromatic aberration. Furthermore, it is particularly preferred if the Abbe number of the material of the first lens L1 with respect to the d-line is greater than or equal to 35, and especially preferably greater than or equal to 40.

[0131] It is preferred if the Abbe number of the material of the first lens L1 with respect to the d-line is less than or equal to 85. This simplifies increasing the refractive index of the material of the first lens L1, resulting in a simplified achievement of a wide viewing angle or a simplified reduction in the cost of the material of the first lens L1. Furthermore, it is particularly preferred if the Abbe number of the material of the first lens L1 with respect to the d-line is less than or equal to 80, particularly preferably less than or equal to 70, and further preferably less than or equal to 65.

[0132] It is preferred if the Abbe number of the material of the second lens L2 with respect to the d-line is greater than or equal to 15. This allows for favorable correction of longitudinal chromatic aberration. Furthermore, it is particularly preferred if the Abbe number of the material of the second lens L2 with respect to the d-line is greater than or equal to 18, and especially preferably greater than or equal to 20.

[0133] It is preferred if the Abbe number of the material of the second lens L2 with respect to the d-line is less than or equal to 60. This allows for favorable correction of lateral chromatic aberration. Furthermore, it is particularly preferred if the Abbe number of the material of the second lens L2 with respect to the d-line is less than or equal to 50, and especially preferably less than or equal to 45.

[0134] It is preferred if the Abbe number of the material of the fourth lens L4 with respect to the d-line is less than or equal to 40. This allows for favorable correction of longitudinal chromatic aberration. Furthermore, it is particularly preferred if the Abbe number of the material of the fourth lens L4 with respect to the d-line is less than or equal to 35, particularly preferably less than or equal to 30, further preferably less than or equal to 25, and even more preferably less than or equal to 20.

[0135] It is preferred if the Abbe number of the material of the sixth lens L6 with respect to the d-line is greater than or equal to 30. This allows for favorable correction of longitudinal and lateral chromatic aberrations. Furthermore, it is particularly preferred if the Abbe number of the material of the sixth lens L6 with respect to the d-line is greater than or equal to 40, particularly preferably greater than or equal to 50, and even more preferably greater than or equal to 55.

[0136] It is preferred if the Abbe number of the material of the sixth lens L6 with respect to the d-line is less than or equal to 80. This simplifies reducing the cost of the material of the sixth lens L6 or increasing the refractive index of the sixth lens L6, resulting in simplified correction of field curvature. Additionally, it is particularly preferred if the Abbe number of the material of the sixth lens L6 with respect to the d-line is less than or equal to 70, and particularly preferably less than or equal to 65.

[0137] In the imaging lenses according to the first and second embodiments of the present invention, it is preferred that exactly one of the surfaces of each lens from the first lens L1 to the seventh lens L7 is aspherical. This makes it possible to correct various aberrations effectively.

[0138] It is preferred if at least exactly one of the surfaces of the second lens L2 is aspherical. By configuring at least one of the surfaces of the second lens L2 as aspherical, the correction of field curvature and spherical aberration is simplified. This makes it possible to achieve a favorable resolution. It is particularly preferred if both surfaces of the second lens L2 are aspherical.

[0139] It is preferred if the object-side surface of the second lens L2 is aspherical. This simplifies the effective correction of spherical aberration, astigmatism, and distortion.

[0140] It is preferred if the image-side surface of the second lens L2 is aspherical. This simplifies the effective correction of spherical aberration, astigmatism, and distortion.

[0141] It is preferred that the object-side surface of the second lens L2 has a shape in which the center (paraxial region) has a positive refractive power and the edge of the effective diameter has a weaker positive refractive power than the center. Alternatively, it is preferred that the object-side surface of the second lens L2 has a shape in which the center has a positive refractive power and the edge of the effective diameter has a negative refractive power. This simplifies the correction of spherical aberration and astigmatism.

[0142] In aspheric surfaces, a convex surface (a positive refractive power) and a concave surface (a negative refractive power) should be considered in paraxial regions unless otherwise specified. The refractive power at each point in regions outside the paraxial areas of aspheric surfaces should be determined as a function of whether the absolute value of the radius of curvature at that point is greater or less than the absolute value of the paraxial radius of curvature. In such a case, the radius of curvature at that point is the distance from that point to the point where the surface normal at that point intersects the optical axis. If the absolute value of the radius of curvature at a point on an aspheric surface is greater than the absolute value of the paraxial radius of curvature, the refractive power at that point is less than that in the paraxial regions.If the absolute value of the radius of curvature at a certain point on an aspherical surface is smaller than the absolute value of the paraxial radius of curvature, the refractive power at that point is greater (stronger) than those in the paraxial regions.

[0143] In aspheric surfaces, whether a surface is convex (positive refractive power) or concave (negative refractive power) at each point in regions outside the paraxial range depends on which side of a point where a surface intersects the optical axis is located. If a surface is on the object side, and a point where the normal intersects the optical axis is on the image side of a point where a surface intersects the optical axis, then the surface at that point is convex (positive refractive power).If a point where the normal line intersects the optical axis lies on the object side of a point where a surface intersects the optical axis, then the surface at that point is concave (negative refractive power). If a point where the normal line intersects the optical axis lies on the object side of a point where a surface intersects the optical axis, then the surface at that point is convex (positive refractive power). If a point where the normal line intersects the optical axis lies on the image side of a point where a surface intersects the optical axis, then the surface at that point is concave (negative refractive power).

[0144] It should be noted that the "effective diameter of a surface" refers to the diameter of a circle constructed through an outermost point in the radial direction (a point furthest from the optical axis) of the points where all image-forming rays intersect lens surfaces, and the expression "edge of the effective diameter" refers to this outermost point. It should be noted that in systems exhibiting rotational symmetry with respect to the optical axis, a graph constructed through the outermost points is a circle. However, in systems lacking rotational symmetry, the graph is not a circle. In such cases, the diameter of an equivalent circle may be the effective diameter.

[0145] The following section describes the shape of an aspherical surface in detail. Fig. Figure 2 is a diagram for describing the shape of a surface of the second lens. Here, i is a lens surface of each lens. "i" is a symbol representing the corresponding lens surface. For example, if the object-side surface of the second lens L2 is represented by 3, the following description regarding the object-side surface of the second lens L2 with i can be understood as 3. Furthermore, if a certain point on a lens surface i is denoted by Xi, and an intersection of the normal line at that point and the optical axis is denoted by Pi, then the length (|Xi - Pi|) of Xi - Pi is defined as the absolute value |RXi| of the radius of curvature at point Xi, and Pi is defined as the center of curvature at point Xi. Furthermore, an intersection of the i-th lens surface and the optical axis is denoted by Qi.In this case, the refractive power at a point Xi is defined depending on whether a point Pi lies on the object side or the image side, based on a point Qi as a reference. On the object-side surface, if a point Pi lies on the image side of a point Qi, the refractive power is defined as positive, whereas if a point Pi lies on the object side of a point Qi, the refractive power is defined as negative. On the image-side surface, if a point Pi lies on the object side of a point Qi, the refractive power is defined as positive, whereas if a point Pi lies on the image side of a point Qi, the refractive power is defined as negative.

[0146] When comparing the refractive power at the center with the refractive power at point Xi, the absolute value of the radius of curvature at the center (paraxial radius of curvature) is compared with the absolute value |RXi| of the radius of curvature at point Xi. If |RXi| is smaller than the absolute value of the paraxial radius of curvature, the refractive power at point Xi is greater than the refractive power at the center. Conversely, if |RXi| is larger than the absolute value of the paraxial radius of curvature, the refractive power at point Xi is weaker than the refractive power at the center. The same applies to both cases: the case of a surface having a positive refractive power and the case of a surface having a negative refractive power.

[0147] With reference to Fig. 2 describes the shape of the object-side surface of the second lens L2 above. Fig. Figure 2 illustrates a diagram of the optical paths of the in Fig. 1 illustrated imaging lens 1. In Fig. 2 is a point Q3, the center of the object-side surface of the second lens L2 and an intersection point of the object-side surface of the second lens L2 and the optical axis Z. Furthermore, in Fig. 2 the point X3 on the object-side surface of the second lens L2 at an edge of the effective diameter and is an intersection point of the outermost ray encompassed in off-axis rays 3 and the object-side surface of the second lens L2. In Fig. Although point X3 lies at the edge of the effective diameter, point X3 is any point on the object-side surface of the second lens L2. Therefore, other points can be considered in the same way.

[0148] In this case, the intersection of the normal line of a lens surface at a point X3 with the optical axis Z is defined as a point P3, as shown in Fig. As illustrated in Figure 2, a line segment X3 - P3 connecting points X3 and P3 is defined as the radius of curvature RX3 at point X3, and the length |X3 - P3| of the line segment X3 - P3 is defined as the absolute value |RX3| of the radius of curvature RX3. That is, |X3 - P3| is |RX3|. Furthermore, the radius of curvature at point Q3, i.e., the radius of curvature at the center of the object-side surface of the second lens L2, is denoted by R3, and its absolute value is denoted as |R3| (in Figure 2). Fig. 2 not shown because the value of |R3| is extremely large).

[0149] For example, the expression “a shape in which the center has a positive refractive power and the edge of the effective diameter has a negative refractive power” of the object-side surface of the second lens L2 described above, where a point X3 is the edge of the effective diameter, means a convex shape in the paraxial region, encompassing a point Q3, and a shape in which a point P3 lies on the object side of point Q3.

[0150] Furthermore, the expression "the center has a positive refractive power and the edge of the effective diameter has a weaker positive refractive power than that of the center" means, with respect to the object-side surface of the second lens L2, if a point X3 is the edge of the effective diameter, a convex shape in the paraxial region comprising a point Q3, and a shape in which a point P3 lies on the image side of point Q3 and the absolute value |RX3| of the radius of curvature at a point X3 is greater than the absolute value |R3| of the radius of curvature at point Q3.

[0151] The object-side surface of the second lens L2 can have a shape in which the center has a negative refractive power and the edge of the effective diameter has a weaker negative refractive power than that of the center. This simplifies the correction of spherical aberration and astigmatism.

[0152] Additionally, the object-side surface of the second lens L2 can have a shape in which the center has a positive refractive power and the edge of the effective diameter has a stronger positive refractive power than that of the center. This simplifies the correction of astigmatism.

[0153] It is preferred that the image-side surface of the second lens L2 has a shape in which the center has a positive refractive power and the edge of the effective diameter has a weaker positive refractive power than that of the center, or a shape in which the center has a positive refractive power and the edge of the effective diameter has a negative refractive power. This simplifies the correction of spherical aberration and astigmatism.

[0154] It is preferred if at least exactly one of the surfaces of the third lens L3 is aspherical. By configuring at least exactly one of the surfaces of the third lens L3 as aspherical, the correction of spherical aberration and astigmatism is simplified. This makes it possible to achieve a favorable resolution. It is particularly preferred if both surfaces of the third lens L3 are aspherical.

[0155] It is preferred if the object-side surface of the third lens L3 is aspherical. This simplifies the favorable correction of spherical aberration and astigmatism.

[0156] The object-side surface of the third lens L3 can have a shape in which the center has a positive refractive power and the edge of the effective diameter has a weaker positive refractive power than that of the center. This simplifies the correction of spherical aberration and astigmatism.

[0157] It is preferred if the image-side surface of the third lens L3 is aspherical. This simplifies the effective correction of spherical aberration.

[0158] The image-side surface of the third lens L3 can have a shape in which the center has a positive refractive power and the edge of the effective diameter has a stronger positive refractive power than that of the center. This simplifies the correction of spherical aberration.

[0159] It is preferred if at least exactly one of the surfaces of the fourth lens L4 is aspherical.

[0160] Configuring at least one of the surfaces of the fourth lens L4 as aspherical simplifies the correction of spherical aberration and field curvature. This allows for achieving favorable resolution. It is particularly advantageous if both surfaces of the fourth lens L4 are aspherical.

[0161] It is preferred that the object-side surface of the fourth lens L4 has a shape in which the center exhibits a negative refractive power and the edge of the effective diameter has a weaker negative refractive power than that of the center. This simplifies the correction of spherical aberration and astigmatism.

[0162] It is preferred that the image-side surface of the fourth lens L4 has a shape in which the center exhibits a negative refractive power and the edge of the effective diameter exhibits a stronger negative refractive power than that of the center. This simplifies the correction of spherical aberration and astigmatism.

[0163] It is preferred if at least exactly one of the surfaces of the fifth lens L5 is aspherical. By configuring at least exactly one of the surfaces of the fifth lens L5 as aspherical, the correction of spherical aberration and field curvature is simplified. This makes it possible to achieve a favorable resolution. It is particularly preferred if both surfaces of the fifth lens L5 are aspherical.

[0164] It is preferred if the object-side surface of the fifth lens L5 is aspherical. This simplifies the favorable correction of spherical aberration and astigmatism.

[0165] It is preferred that the object-side surface of the fifth lens L5 has a shape in which the center has a negative refractive power and the edge of the effective diameter has a stronger negative refractive power than that of the center, or a shape in which the center has a positive refractive power and the edge of the effective diameter has a negative refractive power. This simplifies the correction of spherical aberration.

[0166] The object-side surface of the fifth lens L5 can have a shape in which the center has a positive refractive power and the edge of the effective diameter has a stronger positive refractive power than that of the center. This simplifies the correction of astigmatism.

[0167] It is preferred if the image-side surface of the fifth lens L5 is aspherical. This simplifies the effective correction of spherical aberration and astigmatism.

[0168] The image-side surface of the fifth lens L5 can have a shape in which the center has a positive refractive power and the edge of the effective diameter has a stronger positive refractive power than that of the center. This simplifies the correction of astigmatism.

[0169] The image-side surface of the fifth lens L5 can have a shape in which the center has a positive refractive power and the edge of the effective diameter has a weaker positive refractive power than that of the center. This simplifies the correction of spherical aberration.

[0170] It is preferred if at least exactly one of the surfaces of the seventh lens L7 is aspherical. By configuring at least exactly one of the surfaces of the seventh lens L7 as aspherical, the correction of spherical aberration and astigmatism is simplified. This makes it possible to achieve a favorable resolution. It is particularly preferred if both surfaces of the seventh lens L7 are aspherical.

[0171] It is preferred if the object-side surface of the seventh lens L7 is aspherical. This simplifies the favorable correction of spherical aberration and astigmatism.

[0172] The object-side surface of the seventh lens L7 can have a shape in which the center has a negative refractive power and the edge of the effective diameter has a stronger negative refractive power than that of the center. This simplifies the correction of astigmatism and coma aberration.

[0173] It is preferred if the image-side surface of the seventh lens L7 is aspherical. This simplifies the effective correction of spherical aberration.

[0174] The image-side surface of the seventh lens L7 can have a shape in which the center has a negative refractive power and the edge of the effective diameter has a weaker negative refractive power than that of the center, or a shape in which the center has a negative refractive power and the edge of the effective diameter has a positive refractive power. This simplifies the correction of astigmatism.

[0175] The image-side surface of the seventh lens L7 can have a shape in which the center has a planar surface or a positive refractive power, and the edge of the effective diameter has a stronger positive refractive power than that of the center. This simplifies the correction of astigmatism.

[0176] It is preferred that the material of the first lens L1 be glass. For example, if the imaging lens is used in harsh environments such as vehicle-mounted cameras, surveillance cameras, and the like, the first lens L1, located furthest from the object, must be made of a material resistant to surface deterioration caused by wind and rain, temperature changes due to direct sunlight, and chemicals such as oil, cleaning agents, and the like—that is, a material with high water resistance, weather resistance, acid resistance, chemical resistance, and the like. Furthermore, the first lens L1 must be made of a material that is hard and not easily breakable. Configuring the material to be glass allows these requirements to be met.Alternatively, the material of the first lens L1 can be a transparent ceramic.

[0177] It should be noted that protective agents to increase strength, scratch resistance, and chemical resistance may be applied to the object-side surface of the first lens L1. In this case, the material of the first lens L1 may be plastic. Such a protective agent may be a hard coating or a water-repellent coating.

[0178] For example, lenses for vehicle-based cameras must be resistant to various vibrations. Accordingly, it is preferred if the first lens L1 is thick and the center thickness of the first lens L1 is greater than or equal to 0.5 mm.

[0179] When lenses are used for vehicle-based cameras, they must be usable across a wide temperature range, from ambient temperatures in cold climates to the temperatures inside a vehicle in the tropics during summer. To manufacture optical systems with good environmental resistance sufficient to withstand such conditions, it is preferred that all lenses be made of glass. When the imaging lens is used as a lens for surveillance cameras or vehicle-based cameras, it may be used under a variety of conditions, such as a wide temperature range from high to low temperatures, humid conditions, and the like. To manufacture optical systems that are resistant to these conditions, it is preferred that all lenses be made of glass.

[0180] It is preferred that the materials of any or any combination of the first lens L1 to the seventh lens L7 are plastic. Configuring the materials as plastic simplifies the reduction of the cost and weight of the lens system and allows for the accurate and cost-effective production of aspherical surface shapes, resulting in the possibility of correcting aspherical aberration and field curvature.

[0181] It is preferred that the imaging lens incorporates a plastic lens with a positive refractive power and a plastic lens with a negative refractive power to create a lens system resistant to temperature changes. Generally, plastic lenses exhibit characteristics that vary significantly with temperature, causing focus shifts. However, configuring the lens system to include the plastic lens with a positive refractive power and the plastic lens with a negative refractive power cancels out changes in refractive power, thus minimizing performance degradation.

[0182] Acrylic, a polyolefin-based material, a polycarbonate-based material, an epoxy resin, PET (polyethylene terephthalate), PES (polyethersulfone), a polycarbonate and the like can be used as plastic materials, for example.

[0183] It should be noted that a filter that cuts off blue light from ultraviolet light, or an IR (infrared) cutoff filter that cuts off infrared light, may be provided between the lens system and the image sensor 5, depending on the application of the imaging lens 1. A coating exhibiting the same characteristics as those of the above filters may be applied to the lens surface. Alternatively, materials that absorb ultraviolet light, blue light, infrared light, and the like may be used as the materials for any of the lenses.

[0184] Fig. Figure 1 shows an example in which an optical element PP, representing various types of filters and the like, is arranged between the lens system and the image sensor 5. However, these different types of filters can instead be arranged between the respective lenses. Alternatively, a coating exhibiting the same effects as the different types of filters can be applied to the lens surfaces of any of the lenses encompassed by the imaging objective.

[0185] It should be noted that there is a possibility that the light rays traveling between the respective lenses on the outside of the effective diameter may become scattered light and reach the image surface, resulting in double images (ghosting). Therefore, where necessary, a light-shielding means is preferably provided to block the scattered light. For example, an opaque coating can be applied to sections of the outside of the effective diameters of the lenses, or an opaque plate can be incorporated. Alternatively, opaque plates can be provided as the light-shielding means along the optical paths of the rays that become scattered light. Alternatively, something like a hood can be arranged further towards the object than the lens furthest from the object to block scattered light. Fig. Figure 1 shows an example in which a light-shielding means 11 is provided on the outside of the effective diameter of the image-side surface of the first lens L1. It should be noted that the positions where the light-shielding means are provided do not correspond to the one shown in Figure 1. Fig. The example shown is limited and the light-shielding means can be arranged on other lenses or between the lenses.

[0186] Furthermore, elements such as apertures and the like, which shield peripheral rays, can be positioned between the respective lenses in a region where no actual problems arise with the ratio of the peripheral ray amplitude. Peripheral rays are those rays emitted from an object point outside the optical axis Z, specifically those rays passing through the peripheral portions of the entrance pupil in the optical system. Positioning the element that shields the peripheral rays in this manner allows for an improvement in the image quality of the peripheral areas of the imaging zone. Furthermore, shielding the light that produces double images with this element reduces double images.

[0187] Furthermore, it is preferred if the lens system is configured with only seven lenses, comprising a first lens L1 to a seventh lens L7.

[0188] The imaging device according to the present embodiment is equipped with the imaging lens according to the present embodiment. Accordingly, the imaging device can be configured with a small size, and bright and cost-effective images with high resolution can be obtained when using an image sensor.

[0189] It should be noted that the images captured by the imaging device equipped with the imaging lens according to the first and second embodiments can be displayed on mobile phones (including smartphones). For example, the imaging device equipped with the imaging lens according to the present embodiment is installed in a car as a vehicle-mounted camera, the vehicle-mounted camera capturing images behind and around the car, and the captured images then being displayed on a display device. In such a case, in a car equipped with a navigation system, the captured images can be displayed on the navigation system's display device. If, however, the car does not have a navigation system, a dedicated display device, such as a liquid crystal display or the like, must be installed in the car.However, display units are expensive. On the other hand, the latest mobile phones are equipped with high-performance displays that allow users to view moving images and websites. Using mobile phones as display units for vehicle-mounted cameras eliminates the need to install dedicated display units in cars without navigation systems, making it possible to install vehicle-mounted cameras in cars at a lower cost.

[0190] Images captured by the vehicle-based camera can be transmitted to a mobile phone either wired via cable or wirelessly via infrared communication. Furthermore, when the car's gearshift is engaged in reverse or a turn signal is activated, the images captured by the vehicle-based camera can be automatically displayed on the mobile phone's screen by synchronizing the mobile phone's operating status with that of the car.

[0191] It should be noted that the display device for showing the images captured by the vehicle-based camera is not limited to a mobile phone and can be a portable data terminal such as a PDA, a compact personal computer, or a laptop car navigation system.

[0192] Furthermore, a mobile phone equipped with the imaging lens according to the invention can be mounted in a car to be used as a vehicle-based camera. The latest smartphones have processing capabilities equivalent to those of PCs.

[0193] Accordingly, mobile phone cameras can be used as vehicle-based cameras, for example, by mounting a mobile phone on the dashboard or similar location in the car and pointing the camera forward. A smartphone application could include a function for recognizing white lines and traffic signs and issuing warnings. Furthermore, the mobile phone could be part of a system that issues warnings if the driver is detected nodding off or looking to the side when the camera is pointed at them. Additionally, by pairing the mobile phone with the car, it could be part of a system that performs steering wheel operations. There is a demand for vehicle-based cameras to be resistant to harsh environments, as cars are operated in both high-temperature and low-temperature environments.When the imaging lens according to the invention is mounted on mobile phones, the mobile phones are removed from the cars by the drivers, except while driving. Accordingly, the imaging lens can be designed to be less resistant to the environment; thus, a cost-effective vehicle-based system can be introduced. [Numerical examples of the imaging lens]

[0194] Numerical examples of the imaging lens according to the invention are described below. [Example 1]

[0195] Fig. Figure 3 illustrates a cross-sectional view showing the lens configuration of an imaging lens from Example 1. Fig. 3. The left side is the object side and the right side is the image side. In the same way as in Fig. Figure 1 also shows an aperture diaphragm St, an optical element PP, and an image sensor 5 arranged on the image surface Sim. An aperture diaphragm St in each of the figures does not necessarily represent its shape or size, but rather its position on the optical axis Z. Tables present data relating to the imaging lens of Example 1. In Table 1, (A) denotes basic lens data, (B) denotes miscellaneous data, and (C) denotes aspheric surface data.

[0196] In the basic lens data, column Si shows the i-th (i = 1, 2, 3, ...) surface number, where the value of i increases continuously from the object-side surface of the element furthest from the object, designated 1, towards the image side. Column Ri shows the radii of curvature of the i-th surface, and column Di shows the distances between the i-th surfaces and the (i + 1)-th surfaces along the optical axis Z. Furthermore, column Ndj shows the refractive indices of the j-th (j = 1, 2, 3, ...) elements with respect to the d-line (wavelength: 587.56 nm), where the value of j increases continuously from the element furthest from the object, designated 1, towards the image side. Column vdj shows the number of the j-th optical elements with respect to the d-line.

[0197] It should be noted that the basic lens data also shows an aperture diaphragm St and an optical element PP. The column of surface numbers corresponding to the aperture diaphragm St indicates the letters (St). It should be noted that the sign of the radius of curvature is positive if a surface has a convex surface towards the object side, and negative if a surface has a convex surface towards the image side.

[0198] In various data, L (in air) is the distance (air-converted length corresponds to back focus) along the optical axis Z from the object-side surface of the first lens L1 to the image surface Sim, Bf (in air) is the distance (air-converted length corresponds to back focus) along the optical axis from the image-side surface of the most image-side lens to the image surface Sim, f is the focal length of the entire system, f1 to f7 are the respective focal lengths of the first to seventh lenses L7, f12 is the combined focal length of the first lens L1 and the second lens L2, f45 is the combined focal length of the fourth lens L4 and the fifth lens L5, f123 is the combined focal length of the first lens L1, the second lens L2 and the third lens L3, f234 is the combined focal length of the second lens L2, the third lens L3 and the fourth lens L4, f345 is the combined focal length of the third lens L3.f2345 is the combined focal length of the second lens L2, the third lens L3, the fourth lens L4 and the fifth lens L5, f3456 is the combined focal length of the third lens L3, the fourth lens L4, the fifth lens L5 and the sixth lens L6, and f12345 is the combined focal length of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4 and the fifth lens L5.

[0199] In the basic lens data, the marking “*” indicates surface area numbers of aspherical surfaces. Numerical values ​​of the paraxial radii of curvature (the radii of curvature of the center) are shown as the radii of curvature of aspherical surfaces. The aspherical surface data shows surface area numbers of the aspherical surfaces and aspherical surface coefficients with respect to the aspherical surfaces. It should be noted that “E - n” (n: integer) in each of the numerical values ​​of the aspherical surface coefficients is “× 10 -n “ means and “E + n” means “×10 n “The aspheric surface coefficients are the values ​​of the respective coefficients K, RBm (m = 3, 4, 5, ...11) in the following formula for aspheric surfaces: Zd=C⋅h2 / {1+(1−K⋅C2⋅h2)1 / 2}+ΣRBm⋅hm where Zd is the depth of an aspherical surface (the length of a perpendicular line drawn from a point on an aspherical surface with height h to a plane perpendicular to the optical axis, touching the vertex of the aspherical surface). h is the height (the distance from the optical axis to a lens surface), C is an inverse number of a paraxial radius of curvature, K, RBm are aspherical surface coefficients (m = 3, 4, 5, ...11).

[0200] In each of the following tables, mm is used as the unit of length; however, other suitable units may also be used, as optical systems are usable even when proportionally enlarged or miniaturized. Additionally, the numerical values ​​in Table 1 are rounded to a predetermined number of decimal places.

[0201] Fig. Figure 29 are diagrams illustrating, in order from the left side of the drawing sheet, spherical aberration, astigmatism, distortion, and lateral chromatic aberration of the imaging lens from Example 1. F in each of the spherical aberration diagrams refers to an F-number, and ω in each of the other aberration diagrams refers to half a viewing angle. Distortion diagrams show the displacement range from an ideal image height f × tan(φ) using the focal length f of the entire system and a viewing angle φ (which is one variable 0 ≤ φ ≤ ω). Each aberration diagram shows aberration with respect to the d-line (wavelength: 587.56 nm) as the reference wavelength.The spherical aberration diagram also shows aberrations with respect to the F-line (wavelength: 486.13 nm), the C-line (wavelength: 656.27 nm), the s-line (wavelength: 852.11 nm), and the offence against the sine condition (SNC). The lateral chromatic aberration diagram also shows aberrations with respect to the F-line, the C-line, and the s-line. The line types in the lateral chromatic aberration diagram are the same as those in the spherical aberration diagram; accordingly, redundant descriptions are omitted.

[0202] The elements in the data, their meanings, and the way in which they are shown in the descriptions above for Example 1 also apply to the following examples, unless otherwise stated. [Example 2]

[0203] Fig. Figure 4 is a cross-sectional view illustrating the imaging lens of Example 2. Table 2 presents basic lens data, miscellaneous data, and aspherical surface data relating to the imaging lens of Example 2. Fig. Figure 30 illustrates, in order starting from the left side of the drawing sheet, a diagram of spherical aberration, an astigmatism diagram, a distortion diagram and a lateral chromatic aberration diagram of the imaging lens of Example 2. [Example 3]

[0204] Fig. Figure 5 is a cross-sectional view illustrating the imaging lens of Example 3. Table 3 presents basic lens data, miscellaneous data, and aspherical surface data relating to the imaging lens of Example 3. Fig. Figure 31 illustrates, in order starting from the left side of the drawing sheet, a diagram of spherical aberration, an astigmatism diagram, a distortion diagram and a lateral chromatic aberration diagram of the imaging lens of Example 3. [Example 4]

[0205] Fig. Figure 6 is a cross-sectional view illustrating the imaging lens of Example 4. Table 4 presents basic lens data, miscellaneous data, and aspherical surface data relating to the imaging lens of Example 6. Fig. Figure 32 illustrates, in order starting from the left side of the drawing sheet, a diagram of spherical aberration, an astigmatism diagram, a distortion diagram and a lateral chromatic aberration diagram of the imaging lens of Example 4. [Example 5]

[0206] Fig. Figure 7 is a cross-sectional view illustrating the imaging lens of Example 5. Table 5 presents basic lens data, miscellaneous data, and aspherical surface data relating to the imaging lens of Example 5. Fig. Figure 33 illustrates, in order starting from the left side of the drawing sheet, a diagram of spherical aberration, an astigmatism diagram, a distortion diagram and a lateral chromatic aberration diagram of the imaging lens of Example 5. [Example 6]

[0207] Fig. Figure 8 is a cross-sectional view illustrating the imaging lens of Example 6. Table 6 presents basic lens data, miscellaneous data, and aspherical surface data relating to the imaging lens of Example 6. Fig. Figure 34 illustrates, in order starting from the left side of the drawing sheet, a diagram of spherical aberration, an astigmatism diagram, a distortion diagram and a lateral chromatic aberration diagram of the imaging lens of Example 6. [Example 7]

[0208] Fig. Figure 9 is a cross-sectional view illustrating the imaging lens of Example 7. Table 7 presents basic lens data, miscellaneous data, and aspherical surface data relating to the imaging lens of Example 7. Fig. Figure 35 illustrates, in order starting from the left side of the drawing sheet, a diagram of spherical aberration, an astigmatism diagram, a distortion diagram and a lateral chromatic aberration diagram of the imaging lens of Example 7. [Example 8]

[0209] Fig. Figure 10 is a cross-sectional view illustrating the imaging lens of Example 8. Table 8 presents basic lens data, miscellaneous data, and aspherical surface data relating to the imaging lens of Example 8. Fig. Figure 36 illustrates, in order starting from the left side of the drawing sheet, a diagram of spherical aberration, an astigmatism diagram, a distortion diagram and a lateral chromatic aberration diagram of the imaging lens of Example 8. [Example 9]

[0210] Fig. Figure 11 is a cross-sectional view illustrating the imaging lens of Example 9. Table 9 presents basic lens data, miscellaneous data, and aspherical surface data relating to the imaging lens of Example 9. Fig. Figure 37 illustrates, in order starting from the left side of the drawing sheet, a diagram of spherical aberration, an astigmatism diagram, a distortion diagram and a lateral chromatic aberration diagram of the imaging lens of Example 9. [Example 10]

[0211] Fig. Figure 12 is a cross-sectional view illustrating the imaging lens of Example 10. Table 10 presents basic lens data, miscellaneous data, and aspherical surface data relating to the imaging lens of Example 10. Fig. Figure 38 illustrates, in order starting from the left side of the drawing sheet, a diagram of spherical aberration, an astigmatism diagram, a distortion diagram and a lateral chromatic aberration diagram of the imaging lens of Example 10. [Example 11]

[0212] Fig. Figure 13 is a cross-sectional view illustrating the imaging lens of Example 11. Table 11 presents basic lens data, miscellaneous data, and aspherical surface data relating to the imaging lens of Example 11. Fig. Figure 39 illustrates, in order starting from the left side of the drawing sheet, a diagram of spherical aberration, an astigmatism diagram, a distortion diagram and a lateral chromatic aberration diagram of the imaging lens of Example 11. [Example 12]

[0213] Fig. Figure 14 is a cross-sectional view illustrating the imaging lens of Example 12. Table 12 presents basic lens data, miscellaneous data, and aspherical surface data relating to the imaging lens of Example 12. Fig. Figure 40 illustrates, in order starting from the left side of the drawing sheet, a diagram of spherical aberration, an astigmatism diagram, a distortion diagram and a lateral chromatic aberration diagram of the imaging lens of Example 12. [Example 13]

[0214] Fig. Figure 15 is a cross-sectional view illustrating the imaging lens of Example 13. Table 13 presents basic lens data, miscellaneous data, and aspherical surface data relating to the imaging lens of Example 13. Fig. Figure 41 illustrates, in order starting from the left side of the drawing sheet, a diagram of spherical aberration, an astigmatism diagram, a distortion diagram and a lateral chromatic aberration diagram of the imaging lens of Example 13. [Example 14]

[0215] Fig. Figure 16 is a cross-sectional view illustrating the imaging lens of Example 14. Table 14 presents basic lens data, miscellaneous data, and aspherical surface data relating to the imaging lens of Example 14. Fig. Figure 42 illustrates, in order starting from the left side of the drawing sheet, a diagram of spherical aberration, an astigmatism diagram, a distortion diagram and a lateral chromatic aberration diagram of the imaging lens of Example 14. [Example 15]

[0216] Fig. Figure 17 is a cross-sectional view illustrating the imaging lens of Example 15. Table 15 presents basic lens data, miscellaneous data, and aspherical surface data relating to the imaging lens of Example 15. Fig. Figure 43 illustrates, in order starting from the left side of the drawing sheet, a diagram of spherical aberration, an astigmatism diagram, a distortion diagram and a lateral chromatic aberration diagram of the imaging lens of Example 15. [Example 16]

[0217] Fig. Figure 18 is a cross-sectional view illustrating the imaging lens of Example 16. Table 16 presents basic lens data, miscellaneous data, and aspherical surface data relating to the imaging lens of Example 16. Fig. Figure 44 illustrates, in order starting from the left side of the drawing sheet, a diagram of spherical aberration, an astigmatism diagram, a distortion diagram and a lateral chromatic aberration diagram of the imaging lens of Example 16. [Example 17]

[0218] Fig. Figure 19 is a cross-sectional view illustrating the imaging lens of Example 17. Table 17 presents basic lens data, miscellaneous data, and aspherical surface data relating to the imaging lens of Example 17. Fig. Figure 45 illustrates, in order starting from the left side of the drawing sheet, a diagram of spherical aberration, an astigmatism diagram, a distortion diagram and a lateral chromatic aberration diagram of the imaging lens of Example 17. [Example 18]

[0219] Fig. Figure 20 is a cross-sectional view illustrating the imaging lens of Example 18. Table 18 presents basic lens data, miscellaneous data, and aspherical surface data relating to the imaging lens of Example 18. Fig. Figure 46 illustrates, in order starting from the left side of the drawing sheet, a diagram of spherical aberration, an astigmatism diagram, a distortion diagram and a lateral chromatic aberration diagram of the imaging lens of Example 18. [Example 19]

[0220] Fig. Figure 21 is a cross-sectional view illustrating the imaging lens of Example 19. Table 19 presents basic lens data, miscellaneous data, and aspherical surface data relating to the imaging lens of Example 19. Fig. Figure 47 illustrates, in order starting from the left side of the drawing sheet, a diagram of spherical aberration, an astigmatism diagram, a distortion diagram and a lateral chromatic aberration diagram of the imaging lens of Example 19. [Example 20]

[0221] Fig. Figure 22 is a cross-sectional view illustrating the imaging lens of Example 20. Table 20 presents basic lens data, miscellaneous data, and aspherical surface data relating to the imaging lens of Example 20. Fig. Figure 48 illustrates, in order starting from the left side of the drawing sheet, a diagram of spherical aberration, an astigmatism diagram, a distortion diagram and a lateral chromatic aberration diagram of the imaging lens of Example 20. [Example 21]

[0222] Fig. Figure 23 is a cross-sectional view illustrating the imaging lens of Example 21. Table 21 presents basic lens data, miscellaneous data, and aspherical surface data relating to the imaging lens of Example 21. Fig. Figure 49 illustrates, in order starting from the left side of the drawing sheet, a diagram of spherical aberration, an astigmatism diagram, a distortion diagram and a lateral chromatic aberration diagram of the imaging lens of Example 21. [Example 22]

[0223] Fig. Figure 24 is a cross-sectional view illustrating the imaging lens of Example 22. Table 22 presents basic lens data, miscellaneous data, and aspherical surface data relating to the imaging lens of Example 22. Fig. Figure 50 illustrates, in order starting from the left side of the drawing sheet, a diagram of spherical aberration, an astigmatism diagram, a distortion diagram and a lateral chromatic aberration diagram of the imaging lens of Example 22. [Example 23]

[0224] Fig. Figure 25 is a cross-sectional view illustrating the imaging lens of Example 23. Table 23 presents basic lens data, miscellaneous data, and aspherical surface data relating to the imaging lens of Example 23. Fig. Figure 51 illustrates, in order starting from the left side of the drawing sheet, a diagram of spherical aberration, an astigmatism diagram, a distortion diagram and a lateral chromatic aberration diagram of the imaging lens of Example 23. [Example 24]

[0225] Fig. Figure 26 is a cross-sectional view illustrating the imaging lens of Example 24. Table 24 presents basic lens data, miscellaneous data, and aspherical surface data relating to the imaging lens of Example 24. Fig. Figure 52 illustrates, in order starting from the left side of the drawing sheet, a diagram of spherical aberration, an astigmatism diagram, a distortion diagram and a lateral chromatic aberration diagram of the imaging lens of Example 24. [Example 25]

[0226] Fig. Figure 27 is a cross-sectional view illustrating the imaging lens of Example 25. Table 25 presents basic lens data, miscellaneous data, and aspherical surface data relating to the imaging lens of Example 25. Fig. Figure 53 illustrates, in order starting from the left side of the drawing sheet, a diagram of spherical aberration, an astigmatism diagram, a distortion diagram and a lateral chromatic aberration diagram of the imaging lens of Example 25. [Example 26]

[0227] Fig. Figure 28 is a cross-sectional view illustrating the imaging lens of Example 26. Table 26 presents basic lens data, miscellaneous data, and aspherical surface data relating to the imaging lens of Example 26. Fig. Figure 54 illustrates, in order starting from the left side of the drawing sheet, a diagram of spherical aberration, an astigmatism diagram, a distortion diagram and a lateral chromatic aberration diagram of the imaging lens of Example 26.

[0228] Regarding the imaging lenses of Examples 1 to 12 of Examples 1 to 26 above, the material for all lenses is glass. In Examples 13 to 25, a first lens L1, a second lens L2, and a sixth lens L6 are glass, and a third lens L3, a fourth lens L4, a fifth lens L5, and a seventh lens L7 are plastic. In Example 26, a first lens L1, a third lens L3, and a sixth lens L6 are glass, and a second lens L2, a fourth lens L4, a fifth lens L5, and a seventh lens L7 are plastic.

[0229] Tables 27 and 28 present the values ​​of the imaging lens corresponding to the condition formulas (1) to (23), which are summarized for each of the examples 1 to 26. The values ​​shown in Tables 27 and 28 refer to the d-line. [Table 27] Beispiele Bedingungsformeln (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) f12 / f vd7 vd3 D4 / f (R3+R4) / (R3-R4) f345 / f f1 / f2 (R14+R15) / (R14-R15) (R5+R6) / (R5-R6) f5 / f (R10+R11) / (R10-R11) (R12+R13) / (R12-R13) 1 -7,08 30,13 63,33 0,05 0,99 3,08 -0,52 -1.00 0,69 1,91 1,10 0,05 2 -8,67 26,3 63,3 0,05 0,96 3,95 -0,53 -1,69 0,64 2,09 1,16 0,02 3 -6,43 26,3 63,3 0,06 0,68 2,56 -0,51 -0,56 0,67 1,80 1,03 -0,03 4 -9,90 38,03 63,33 0,05 1,35 3,50 -0,55 -1.00 0,63 1,90 1,19 0,00 5 -9,21 34,54 63,33 0,05 1,16 3,21 -0,56 -1.00 0,66 1,82 1,11 0,00 6 -3,88 32,10 63,33 0,05 1,09 2,75 -0,45 -1.00 0,31 2,38 2,12 0,03 7 -3,85 26,29 63,33 0,06 0,62 2,68 -0,45 -1,00 0,66 1,76 0,94 -0,05 8 -3,33 41,41 63,33 0,06 0,49 2,19 -0,44 -1.00 0,43 2,12 0,84 -0,56 9 -8,87 26,29 63,33 0,05 0,19 2,82 -0,63 -1,00 -0,25 1,61 1,25 -0,19 10 -3,89 26,29 63,33 0,05 0,66 2,20 -0,48 -1.00 -0,41 1,31 1,00 -0,53 11 -3,30 17,47 63,33 0,05 -0,44 2,19 -0,49 -1.00 -0,60 1,64 1,15 -0,32 12 -5,48 17,47 63,33 0,06 -0,87 2,00 -0,64 -0,72 0,19 1,38 1,00 -0,56 13 -25,61 23,62 55,48 0,06 3,30 5,49 -0,55 -1,00 -0,37 2,02 0,30 -0,26 14 -21,56 23,62 55,48 0,06 3,57 5,01 -0,53 -1,00 -0,27 2,10 0,24 -0,25 15 -21,76 23,62 55,48 0,06 3,13 6,40 -0,54 -1.00 0,14 2,50 0,42 -0,20 16 13,07 23,62 55,48 0,06 3,49 4,68 -0,66 -1,00 0,24 1,77 0,07 -0,13 17 -7,28 23,62 55,48 0,06 3,79 3,88 -0,44 -1,00 0,19 3,30 1,06 -0,10 18 -5,41 23,62 55,48 0,06 2,16 3,81 -0,42 -1,00 -0,18 2,87 1,17 -0,19 19 -4.76 23,62 55,48 0,06 2.29 4,55 -0,39 -1,00 -0.30 3,30 1,21 -0,21 20 -7,54 23,62 55,48 0,05 2,03 4,70 -0,47 -1,00 -0,19 3,08 1,15 -0,17 21 -7,01 23,62 55,48 0,05 2,04 4,08 -0.46 -1.00 -0,04 2,70 1,14 -0,17 22 -4,26 23,62 55,48 0,06 2,34 3,72 -0,36 -1.00 0,13 2,89 1,17 -0,15 23 -6,89 23,62 55,48 0,05 0,64 3,64 -0,54 -1.00 0,41 2,15 0,86 -0,20 24 -20,10 23,62 55,48 0,05 0,86 3,83 -0,64 -1.00 -0,20 1,84 0,97 -0,21 25 -16,69 23,62 55,48 0,06 1,04 3,83 -0.60 -1,00 0,36 2,16 0,94 -0,41 26 -3,25 23,62 63,33 0,05 0,75 3,03 -0.39 -1.00 0,87 2,78 0,97 0,05 [Table 28] Beispiele Bedingungsformeln (13) (14) (15) (16) (17) (18) (19) (20) (21) (22) (23) vd5 f3 / f f2 / f f1 / f f123 / f f234 / f f12345 / f f2345 / f f3456 / f (R8+R9) / (R8-R9) f / f45 1 53,2 1,89 2,55 -1,32 1,38 2,82 2,34 1,81 1,06 -0,26 -0,06 2 53,2 1,83 2,14 -1,13 1,24 2,24 2,98 1,73 1,11 -0,04 -0,18 3 53,2 2,08 2,82 -1,44 1,63 2,93 1,92 1,80 1,00 -0,13 0,07 4 40,9 1,97 2,44 -1,36 1,41 2,92 2,63 1,82 1,08 -0,01 -0,10 5 40,9 1,94 2.41 -1,34 1,42 2,83 2,42 1,79 1,07 -0,18 -0,06 6 40,9 1,48 2,56 -1,16 1,16 1,65 2,54 1,61 1,15 0,35 -0,18 7 53,2 1,75 3,14 -1,41 1,59 3,39 2,54 1,86 1,01 -0,40 -0,04 8 40,9 1,33 2,46 -1,09 1,07 1,52 2,05 1,37 1,21 0,68 -0,20 9 31,3 1,86 1,92 -1,21 1,55 1,74 2,43 1,41 1,02 0,14 -0,06 10 31,3 1,30 2,82 -1,34 1,20 2,25 2,17 1,46 1,15 -0,14 -0,10 11 31,3 2,28 2,54 -1,24 3,39 2,09 2,39 1,48 0,99 0,81 0,16 12 29,8 1,57 1,96 -1,26 1,58 2,04 1,93 1,37 0,95 0,01 0,07 13 55,5 2,45 3.16 -1,74 1,54 7,13 3,66 2,16 1,31 -0,31 -0,17 14 55,5 2,37 3,17 -1,68 1,47 5,71 3,28 2,05 1,35 -0,15 -0,17 15 55,5 2,29 2,96 -1,59 1,41 4.32 4,38 2,16 1,41 -0,10 -0,24 16 55,5 2,58 2,55 -1,69 1,35 6,30 2,33 1,86 1,38 -0,21 -0,10 17 55,5 2,88 3,86 -1,71 2.19 3,67 3,00 2,13 1,17 -1,85 -0,01 18 55,5 3,15 3,99 -1,66 2,92 4,38 3,40 2,19 1,09 -0,98 0,02 19 55,5 3,72 4,21 -1,64 4,16 4,89 4,95 2,43 1,13 -1,07 0,01 20 55,5 4,02 3,52 -1,66 3,59 4,62 4,05 2,28 1,09 -1,03 0,02 21 55,5 3,14 3,61 -1,67 2,61 4,68 3,35 2,22 1,10 -1,03 0,01 22 55,5 2,66 4,58 -1,66 2,52 4,94 3,69 2,29 1,12 -1,05 -0,02 23 55,5 2,68 2,83 -1,52 2,42 3,89 3,26 1,99 1,02 -0,39 0,00 24 55,5 4,61 2,88 -1,85 3,85 5,98 2,93 2,20 0,98 -0,41 0,13 25 55,5 2,99 2,54 -1,52 2,20 3,12 2,79 1,97 1,11 -0,25 0,02 26 55,5 2,01 3,21 -1,24 1,78 2,68 3,07 1,88 1,19 -0,12 -0,08

[0230] As can be seen from the data described above, each of the imaging lenses in examples 1 to 26 is constructed from seven lenses and can be manufactured in a small size. Furthermore, the respective imaging lenses have low f-numbers of 1.5 to 1.6, effectively correcting aberrations and exhibiting high optical performance. These imaging lenses are suitable for use in surveillance cameras, vehicle-mounted cameras, for photographing the front, side, and rear of automobiles, and similar applications. [Design of the imaging device]

[0231] Fig. Figure 55 shows, as an example of use, the aspect of an automobile 100 on which the imaging device equipped with the imaging lens of the present embodiment is attached. Fig.55 The automobile 100 is equipped with an external vehicle camera 101 for photographing a blind spot area on the side surface of its passenger side, an external vehicle camera 102 for photographing a blind spot area behind the automobile 100, and an internal vehicle camera 103, which is provided on the back of a room mirror for photographing the same field of vision as that of the driver. The external vehicle cameras 101, 102, and the internal vehicle camera 103 correspond to the imaging device according to the embodiment of the present invention and are equipped with the imaging lens according to the present embodiment of the present invention and with an imaging element that converts an optical image formed by the imaging lens into an electrical signal.

[0232] All imaging lenses according to the examples of the present invention exhibit the advantageous aspects described above. Accordingly, the external vehicle cameras 101, 102 and the internal vehicle camera 103 can also be configured with larger viewing angles while being small and inexpensive, thus enabling the acquisition of good images even in peripheral areas of the imaging field.

[0233] The present invention has been described with reference to the embodiments and examples. The present invention is not limited to the embodiments and examples described above, and various modifications are possible. For example, values ​​such as the radius of curvature, the surface distances, the refractive indices, the number of lenses of each objective element, and the like are not limited to the values ​​of the numerical examples shown in the tables, but can assume other values.

[0234] It should be noted that all lenses in the examples above are made of homogeneous materials. However, gradient-index lenses can also be used. Furthermore, in some of the examples above, the second lens L2 through the seventh lens L7 are diffractive lenses with aspherical surfaces. A diffractive optical element can be formed on exactly one or more surfaces.

[0235] The embodiment of the imaging device has been described with reference to the figure of an example in which the present invention is applied to a vehicle-based camera. The present invention is not limited to this application and can, for example, be applied to cameras of portable devices, surveillance cameras, and the like.

Claims

[1] Imaging lens comprising, in order starting from the object side, a first lens (L1) with a negative refractive power, a second lens (L2) with a positive refractive power, a third lens (L3) with a positive refractive power, a fourth lens (L4) with a negative refractive power, a fifth lens (L5) with a positive refractive power, a sixth lens (L6) with a positive refractive power and a seventh lens (L7) with a negative refractive power, wherein the following condition formulas are satisfied: f12 / f<−3.2 vd7<55 40 <vd3 where, f12 is the combined focal length of the first lens (L1) and the second lens (L2), f is the focal length of the entire system, vd7 is the Abbe number of the material of the seventh lens (L7) with respect to the d-line, and vd3 is the Abbe number of the material of the third lens (L3) with respect to the d-line. [2] Imaging lens comprising, in order starting from the object side, a first lens (L1) with a negative refractive power, a second lens (L2) with a positive refractive power, a third lens (L3) with a positive refractive power, a fourth lens (L4) with a negative refractive power, a fifth lens (L5) with a positive refractive power, a sixth lens (L6) with a positive refractive power and a seventh lens (L7) with a negative refractive power, wherein The following conditional formulas must be fulfilled: f12 / f<−3.2 D4 / f<0.39 where f12 is the combined focal length of the first lens (L1) and the second lens (L2), f is the focal length of the entire system, and D4 is the air gap between the second lens (L2) and the third lens (L3). [3] Imaging lens according to claim 2, wherein the following condition formula is further satisfied: 40 <vd3 where, vd3 is the Abbe number of the material of the third lens (L3) with respect to the d-line. [4] Imaging lens according to one of claims 1 to 3, wherein the following condition formula is further satisfied: 25 <vd5 where, vd5 is the Abbe number of the material of the fifth lens (L5) with respect to the d-line. [5] Imaging lens according to one of claims 1 to 4, wherein the following condition formula is further satisfied: 0.5 <f3 / f<10 where, f3 is the focal length of the third lens (L3), and f is the focal length of the entire system. [6] Imaging lens according to one of claims 1 to 5, wherein the following condition formula is further satisfied: 0.5 <f2 / f<7 where, f2 is the focal length of the second lens (L2), and f is the focal length of the entire system. [7] Imaging lens according to any one of claims 1 to 6, wherein the following condition formula is satisfied: f1 / f<−0.25 where, f1 is the focal length of the first lens (L1), and f is the focal length of the entire system. [8] Imaging lens according to any one of claims 1 to 7, wherein the following condition formula is satisfied: 0.3 <f123 / f<15 where, f123 is the combined focal length of the first lens (L1), the second lens (L2) and the third lens (L3), and f is the focal length of the entire system. [9] Imaging lens according to any one of claims 1 to 8, wherein the following condition formula is further satisfied: 0.5 <f234 / f<18 where, f234 is the combined focal length of the second lens (L2), the third lens (L3) and the fourth lens (L4), and f is the focal length of the entire system. [10] Imaging lens according to any one of claims 1 to 9, wherein the following condition formula is further satisfied: 0.5 <f12345 / f<10 where, f12345 is the combined focal length of the first lens (L1), the second lens (L2), the third lens (L3), the fourth lens (L4) and the fifth lens (L5), and f is the focal length of the entire system. [11] Imaging lens according to any one of claims 1 to 10, wherein the following condition formula is further satisfied: −5.0<(R14+R15) / (R14−R15)<−0.01 where, R14 is the radius of curvature of the object-side surface of the seventh lens (L7), and R15 is the radius of curvature of the image-side surface of the seventh lens (L7). [12] Imaging lens according to one of claims 1 to 11, wherein the following condition formula is further satisfied: 0.4 <f2345 / f<10 where f2345 is the combined focal length of the second lens (L2), the third lens (L3), the fourth lens (L4) and the fifth lens (L5), and f is the focal length of the entire system. [13] Imaging lens according to one of claims 1 to 12, wherein the following condition formula is further satisfied: 0.1 <f3456 / f<5,0 where, f3456 is the combined focal length of the third lens (L3), the fourth lens (L4), the fifth lens (L5) and the sixth lens (L6), and f is the focal length of the entire system. [14] Imaging lens according to any one of claims 1 to 13, wherein the following condition formula is further satisfied: −4.0<(R8+R9) / (R8−R9)<4.0 where, R8 is the radius of curvature of the object-side surface of the fourth lens (L4), and R9 is the radius of curvature of the image-side surface of the fourth lens (L4). [15] Imaging lens according to any one of claims 1 to 14, wherein the following condition formula is further satisfied: -3 <f / f45<3 where, f45 is the combined focal length of the fourth lens (L4) and the fifth lens (L5), and f is the focal length of the entire system. [16] Imaging device equipped with the imaging lens according to any one of claims 1 to 15.

Images