Imaging lens system and camera module, imaging device, in-vehicle system, mobile device equipped therewith

Abstract

This invention provides an imaging lens system with a wide angle of view and high resolution over a wide temperature range, while also offering telecentric properties. [Solution] In an imaging lens system having, in order from the object side toward the image side, a first lens having negative power with its image side facing concave toward the image side, a second lens having negative power, a third lens having positive power with its object side facing convex toward the object side and its image side facing convex toward the image side, a fourth lens, a fifth lens with its image side facing concave toward the image side, and a sixth lens having positive power with its object side facing convex toward the object side, the fourth lens has an inflection point on at least one of its object side and image side.

Description

Technical Field

[0001] The present invention relates to an imaging lens system, a camera module including the same, an imaging device, an in-vehicle system, and a moving body.

Background Art

[0002] In recent years, an imaging lens system for in-vehicle use has been required to have a lens corresponding to a wide field of view. The imaging lens system for in-vehicle use is used in an in-vehicle camera, and for example, is used for view applications such as front, back, and side, and sensing applications in order to ensure safety when driving a vehicle.

[0003] The imaging lens system of the in-vehicle camera is required to be an imaging lens system having an extremely wide field of view and high bright resolution. Furthermore, an in-vehicle camera mounted on a side mirror or the like of an automobile (vehicle) is required to be lightweight and inexpensive so that it can be used in a wide temperature range because it is mounted close to the outside air in a cold region or a hot region and in a narrow space.

[0004] In addition, it is desirable that the imaging lens system using infrared rays has a telecentricity in which the principal ray is incident at an angle close to perpendicular to the imaging element. In particular, when a band-pass filter or the like is used, when the principal ray incident angle (CRA) to the imaging element is large, a wavelength (short wavelength) shift occurs and the transmittance decreases. Therefore, telecentricity is highly regarded in the imaging lens system. Patent Document 1 describes an imaging lens system in an in-vehicle camera.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] The present invention has been made in view of the above, and provides an imaging lens system with a wide angle of view and a bright image, which also has telecentric properties that provide high resolution over a wide temperature range. [Means for solving the problem]

[0007] In an imaging lens system, the first lens having negative power with its image side facing concave toward the image, the second lens having negative power, the third lens having positive power with its object side facing convex toward the object and its image side facing convex toward the image, the fourth lens, the fifth lens with its image side facing concave toward the image, and the sixth lens having positive power with its object side facing convex toward the object, the fourth lens having an inflection point on at least one of its object side and image side. [Effects of the Invention]

[0008] The present invention provides an imaging lens system with a wide angle of view and high resolution over a wide temperature range, exhibiting telecentric properties. [Brief explanation of the drawing]

[0009] [Figure 1] This is a cross-sectional view of the imaging lens system according to Example 1. [Figure 2A] This is a spherical aberration diagram of the imaging lens system according to Example 1. [Figure 2B] This is a diagram showing the image field curvature of the imaging lens system according to Example 1. [Figure 2C] This is a distortion aberration diagram of the imaging lens system according to Example 1. [Figure 3] This is a cross-sectional view of the imaging lens system according to Example 2. [Figure 4A] This is a spherical aberration diagram of the imaging lens system according to Example 2. [Figure 4B] This is a diagram showing the image field curvature of the imaging lens system according to Example 2. [Figure 4C] This is a distortion aberration diagram of the imaging lens system according to Example 2. [Figure 5] It is a cross-sectional view of the imaging lens system according to Example 3. [Figure 6A] It is a spherical aberration diagram of the imaging lens system according to Example 3. [Figure 6B] It is a diagram of the field curvature of the imaging lens system according to Example 3. [Figure 6C] It is a distortion aberration diagram of the imaging lens system according to Example 3. [Figure 7] It is a cross-sectional view of the imaging lens system according to Example 4. [Figure 8A] It is a spherical aberration diagram of the imaging lens system according to Example 4. [Figure 8B] It is a diagram of the field curvature of the imaging lens system according to Example 4. [Figure 8C] It is a distortion aberration diagram of the imaging lens system according to Example 4. [Figure 9] It is a cross-sectional view of the imaging lens system according to Example 5. [Figure 10A] It is a spherical aberration diagram of the imaging lens system according to Example 5. [Figure 10B] It is a diagram of the field curvature of the imaging lens system according to Example 5. [Figure 10C] It is a distortion aberration diagram of the imaging lens system according to Example 5. [Figure 11] It is a cross-sectional view of the imaging lens system according to Example 6. [Figure 12A] It is a spherical aberration diagram of the imaging lens system according to Example 6. [Figure 12B] It is a diagram of the field curvature of the imaging lens system according to Example 6. [Figure 12C] It is a distortion aberration diagram of the imaging lens system according to Example 6. [Figure 13] It is a cross-sectional view of the imaging lens system according to Example 7. [Figure 14A] It is a spherical aberration diagram of the imaging lens system according to Example 7. [Figure 14B] It is a diagram of the field curvature of the imaging lens system according to Example 7. [Figure 14C] It is a distortion aberration diagram of the imaging lens system according to Example 7. [Figure 15]This is a diagram illustrating the configuration of an imaging device equipped with an imaging lens system. [Figure 16] This is a schematic diagram of a vehicle equipped with an imaging device. [Figure 17] This is a diagram showing the configuration of a vehicle equipped with an imaging device. [Modes for carrying out the invention]

[0010] Embodiments of the present invention will be described below with reference to the drawings and other figures. In the drawings and descriptions of this embodiment, functionally identical elements may be indicated by the same number. The following description shows embodiments in accordance with the principle, but these are for the purpose of understanding this embodiment and are not to be used to interpret this embodiment restrictively. The description of this embodiment is merely a typical example and does not limit the scope of the claims or applications in any way.

[0011] Although this embodiment has been described in sufficient detail for those skilled in the art to implement, it is important to understand that other forms are possible, and that the configuration and structure can be modified and various elements replaced without departing from the scope and spirit of the technical idea. Therefore, the following description should not be interpreted as limiting.

[0012] Furthermore, this embodiment can realize a highly reliable system, particularly in sensing systems, and aims to build resilient infrastructure, promote inclusive and sustainable industrialization, and drive innovation. It targets "9.1: Develop quality, reliable, sustainable and resilient infrastructure, including local and transboundary infrastructure, to support economic development and human well-being, with a focus on affordable and equitable access for all," one of the United Nations' Sustainable Development Goals (SDGs). [Embodiment 1] Hereinafter, based on embodiments of the present invention and with reference to the drawings, the imaging lens system and the camera module, imaging device, in-vehicle system, and mobile body equipped therewith according to the present invention will be described in detail.

[0013] Figure 1 is an example of the first embodiment, and at the same time, it relates to Example 1, which is based on specific numerical values. Before describing the example that includes specific numerical values, first, the fundamental embodiment of the present invention will be described.

[0014] The imaging lens system 11, which has a configuration of 6 lenses, satisfies the following condition (1) when the focal length of the fourth lens L4 is f4. 0.0003≦|1 / f4|≦0.08 ···(1) The imaging lens system 11, which has a configuration of 7 lenses, satisfies the following condition (2) when the focal length of the 4th lens L4 is f4 and the focal length of the 5th lens L5 is f5. 0.0003≦|1 / f4+1 / f5|≦0.08 ···(2) The imaging lens system 11 satisfies the following condition (3) when the focal length of the third lens L3 is f3 and the focal length of the entire optical system is f. 1.5 ≤ f³ / f ≤ 2.0 ···(3) The imaging lens system 11 satisfies the following condition (4), where ttl is the distance from the object-side lens surface S1 of the first lens L1 to the imaging surface S20 of the image sensor 12 on the optical axis O, and f is the focal length of the entire optical system. 5 ≤ ttl / f ≤ 6 ···(4) By satisfying these conditions, the imaging lens system 11 can provide an imaging lens system with a wide angle of view and high resolution over a wide temperature range, while also being bright.

[0015] As an embodiment, the imaging lens system 11 of the camera module 10 will be described as an example including specific numerical values.

[0016] [Example 1] Figure 1 is a cross-sectional view showing the lens configuration of the imaging lens system 11 of the camera module 10 of Embodiment 1. As shown in Figure 1, Embodiment 1 consists of six lenses. The imaging lens system 11 of Embodiment 1 comprises, in the order of the optical axis O direction from the object side toward the image side, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, and a sixth lens L6.

[0017] Furthermore, the imaging lens system 11 includes a front lens group that determines the angle of view characteristics, etc., through the first lens L1 and the second lens L2. In addition, the imaging lens system 11 has a front lens group and a rear lens group that contributes to brightness, light-gathering characteristics, etc., through the third lens L3, fourth lens L4, fifth lens L5, and sixth lens L6, flanking the optical aperture 1.

[0018] The first lens L1 has a lens surface S1 which is the object side of a spherical surface with positive curvature and a convex shape toward the object, facing the object, and a lens surface S2 which is the image side of a spherical surface with positive curvature and a concave shape toward the image. The first lens L1 is a negative lens with negative power (negative refractive power) that diffuses light rays, and is a meniscus-shaped glass lens with a thicker edge than the center.

[0019] The second lens L2 has an aspherical lens surface S3 with positive curvature and a convex shape towards the object side, and an aspherical lens surface S4 with positive curvature and a concave shape towards the image side. The second lens L2 is a negative lens with negative power and is a meniscus-shaped plastic lens.

[0020] The optical diaphragm 1 (STOP) has an opening that allows light rays to pass through the optical diaphragm surface S5, and the amount of light rays is set by the diameter of the opening. The optical diaphragm 1 is made of a non-transparent material and has a thin shape.

[0021] The third lens L3 has a spherical lens surface S6 with positive curvature that is convex towards the object side, and a spherical lens surface S7 with negative curvature that is convex towards the image side. The third lens, L3, is a glass lens with positive power where light rays converge, and it is thicker towards the center than towards the edges.

[0022] The fourth lens L4 has an aspherical lens surface S8 with positive curvature and a convex shape towards the object side, and an aspherical lens surface S9 with positive curvature and a concave shape towards the image side. The fourth lens L4 is a plastic lens with negative power.

[0023] Furthermore, the lens surface S8 has a convex shape towards the object in the paraxial region passing through the optical axis O within the effective image circle diameter, and a concave shape in the edge region. In other words, the lens surface S8 has one inflection point IP8.

[0024] Furthermore, the lens surface S9 has a concave shape on the image side in the paraxial portion passing through the optical axis O within the effective image circle diameter, and a convex shape in the edge portion. In other words, the lens surface S8 has one inflection point IP9.

[0025] Thus, the fourth lens L4, by having an inflection point, corrects spherical aberration, coma aberration, etc., that occur at bright Fno. Furthermore, even if the first lens L1 is small, the effective image circle diameter (image height) can be secured. The fourth lens L4 may have at least one of the inflection point IP8 on the lens surface S8 and the inflection point IP9 on the lens surface S9.

[0026] The fifth lens L5 has an aspherical lens surface S10 with positive curvature and a convex shape on the object side, and an aspherical lens surface S11 with positive curvature and a concave shape on the image side. The fifth lens L5 is a negative lens with negative power and is a meniscus-shaped plastic lens.

[0027] In a six-lens configuration, the lens surface S11, which is the image side of the fifth lens L5 (the second lens from the image side), does not have an inflection point and has a stronger negative power from the center to the edge. In other words, the negative power of the lens surface S11 is stronger at the edge than at the center.

[0028] The concave image side (lens surface S11) of the fifth lens L5 transmits light rays from the fourth lens L4, ensuring a good peripheral illumination ratio at the periphery of the image sensor 12 and preventing vignetting.

[0029] The sixth lens L6 has an aspherical lens surface S12 with positive curvature that is convex towards the object side, and an aspherical lens surface S13 with negative curvature that is convex towards the image side. The sixth lens L6 is a positive lens with positive power and is made of plastic.

[0030] In a six-lens configuration, the lens surface S12 of the sixth lens L6, which is the closest lens to the first image sensor 12 from the image side, has no inflection point and possesses a strong positive power where light rays converge from the center to the edge. In other words, the positive power of the lens surface S12 is stronger at the edge than at the center.

[0031] The concave image side (lens surface S11) of the fifth lens L5 and the convex object side (lens surface S12) of the sixth lens L6, through which light rays from the fourth lens L4 pass, can improve the principal ray incidence angle (CRA) to the image sensor 12. Therefore, when light rays are incident on the bandpass filter 14 installed between the sixth lens L6 and the image sensor 12, the short-wavelength shift of the transmitted wavelength can be suppressed and transmittance can be ensured.

[0032] The first lens L1 is a glass lens with excellent weather resistance, capable of withstanding natural outdoor environments such as sunlight, temperature, humidity, and rain. The lens surface S1 of the first lens L1 may also be coated with a water-repellent or water-resistant coating. The third lens L3 is a glass lens capable of suppressing focus fluctuations due to changes in ambient temperature, etc.

[0033] Furthermore, the second lens L2, fourth lens L4, fifth lens L5, and sixth lens L6 are made of plastic to achieve weight reduction, cost reduction, and impact resistance. At least one of the second lens L2, fourth lens L4, fifth lens L5, and sixth lens L6 may be a plastic lens.

[0034] Thus, the imaging lens system 11 comprises, in order from the object side to the image side, a first lens L1 having negative power with its image side facing concave toward the image side, a second lens L2 having negative power, a third lens L3 having positive power with its object side facing convex toward the object side and its image side facing convex toward the image side, a fourth lens L4, a fifth lens L5 with its image side facing concave toward the image side, and a sixth lens L6 having positive power with its object side facing convex toward the object side. In this imaging lens system, the fourth lens L4 has an inflection point on at least one of its object side and image side, thereby providing an imaging lens system with a wide angle of view and brightness, and high resolution over a wide temperature range. Furthermore, the imaging lens system 11, by having a fifth lens L5 with a concave image side and a sixth lens L6 with a convex object side, can provide an imaging lens system with telecentricity.

[0035] Furthermore, each lens surface of the first lens L1 to the sixth lens L6 may be curved, similar to the lens surface S2 of the first lens L1, as long as at least the surface with an effective image circle diameter passing through the optical axis O is curved, and the edges may be flat.

[0036] The bandpass filter 14 (BPF) of the camera module 10 is a filter that allows only light rays of a predetermined wavelength to pass through. For example, the bandpass filter 14 transmits infrared light rays in the wavelength range of 750 nm to 1000 nm. The bandpass filter 14 has a BPF surface S16 and a BPF surface S17.

[0037] The cover glass 13 (CG) of the camera module 10 is a glass plate for protecting the image sensor 12. The cover glass 13 has a CG surface S18 and a CG surface S19. The image sensor 12 (IMG) is an element capable of capturing light rays (images) in the wavelength range of 750 nm to 1000 nm, and has an imaging surface S20.

[0038] Thus, the camera module 10 comprises an imaging lens system 11, an optical aperture 1, a bandpass filter 14, a cover glass 13, and an image sensor 12, with each edge fixed to the housing (barrel, etc.) of the camera module 10 or the imaging lens system 11 by flanges or the like. The optical aperture 1 is installed integrally with the imaging lens system 11, but it is not an essential component of the imaging lens system 11. The imaging lens system 11 may also be provided with flanges or the like that substitute for the function of an aperture diaphragm and thus serve as the optical aperture 1.

[0039] Furthermore, the optical aperture 1 is installed between the second lens L2 and the third lens L3, but it may also be installed between the third lens L3 and the fourth lens L4, or at any position between the first lens L1 and the sixth lens L6. By installing the optical aperture 1, the front element diameter of the first lens L1 can be further reduced in the imaging lens system 11. Moreover, the imaging lens system 11 may have multiple optical apertures.

[0040] Furthermore, although the camera module 10 includes a bandpass filter 14 between the sixth lens L6 and the cover glass 13, it may also be placed between the cover glass 13 and the image sensor 12, i.e., on the object side of the image sensor 12. Moreover, the camera module 10 does not necessarily need the cover glass 13.

[0041] Table 1 shows the lens data for each lens surface of the imaging lens system 11 in Example 1.

[0042] [Table 1]

[0043] Table 1, the lens data table, shows the paraxial radius of curvature R, interplanar spacing D, refractive index Nd, and Abbe number vd for each surface. The interplanar spacing D(i) is the distance between surfaces S(i) and S(i+1) on the optical axis O. For example, it indicates that the central thickness on the optical axis O, which is the distance between the object-side lens surface S1 and the image-side lens surface S2, is 1.000 mm. Surfaces marked with an asterisk (e.g., lens surface S3 of the second lens L2) indicate aspherical lens surfaces. That is, the second lens L2, fourth lens L4, fifth lens L5, and sixth lens L6 are aspherical lenses. Such aspherical lens surfaces can effectively correct spherical aberration and coma aberration. The aspherical shapes used for the aspherical lens surfaces in Table 1 are represented by Equation 1.

[0044]

number

[0045] Here, Z is the sag amount. c is the reciprocal of the paraxial radius of curvature R, k is the conicity coefficient, and r is the height from the optical axis. A4, A6, A8, A10, A12, A14, and A16 represent the 4th, 6th, 8th, 10th, 12th, 14th, and 16th order aspherical coefficients, respectively.

[0046] Table 2 shows the aspheric coefficients and other parameters used to define the aspherical shape of the lens surface designated as aspherical in Table 1 in the imaging lens system 11 of Example 1.

[0047] [Table 2]

[0048] In Table 2, for example, "-6.589901E-03" means "-6.589901 × 10 to the power of -3".

[0049] Table 3 shows the characteristic values ​​for the imaging lens system 11 of Example 1, as shown in Tables 1 and 2.

[0050] [Table 3]

[0051] In the imaging lens system 11, Fno is the F-number (F-value). An Fno of 1.3 ensures sufficient light and allows for a brighter imaging lens. Fno is generally smaller than Fno 2.8, which is considered a dark optical system. The imaging lens system 11 is preferably in the range of 1.5 to 1. The imaging lens system 11 corrects various aberrations such as spherical aberration and coma aberration that occur when the effective aperture (e.g., entrance pupil diameter, exit pupil diameter) is increased and a bright optical system (e.g., F-number of 1.3) is achieved.

[0052] ω represents the half-angle of view, and the full-angle view is 2ω. For example, in Example 1, the half-angle of view ω is 73.8° and the horizontal angle of view (full-angle) is 147.6°, making it an ultra-wide-angle lens that supports a wide field of view of 100° or more. This lens may also be a fisheye lens with a horizontal angle of view of 180° or more. The range of the horizontal angle of view (full-angle) is preferably 120° to 160°.

[0053] f represents the focal length of the entire lens system from the first lens L1 to the sixth lens L6. f1 represents the focal length of the first lens L1. f2 represents the focal length of the second lens L2, f3 represents the focal length of the third lens L3, f4 represents the focal length of the fourth lens L4, f5 represents the focal length of the fifth lens L5, and f6 represents the focal length of the sixth lens L6. Additionally, ttl represents the total optical length along the optical axis O from the object-side lens surface S1 of the first lens L1 to the imaging surface S20 of the image sensor 12. bf represents the distance along the optical axis O from the image-side lens surface S13 of the sixth lens L6 to the imaging surface S20 of the image sensor 12.

[0054] Figure 2A shows the spherical aberration of the imaging lens system 11 of Example 1. The horizontal axis in Figure 2A represents the distance in the direction of the optical axis O. The vertical axis represents the pupil coordinates relative to the entrance pupil diameter. The solid line in Figure 2A represents a ray with a wavelength of 0.94 μm. Thus, the imaging lens system 11 of Example 1 has minimal distance deviation in the direction of the optical axis O, and the spherical aberration is corrected to an appropriate range.

[0055] Figure 2B shows the field curvature of the imaging lens system 11 of Example 1. In Figure 2B, the horizontal axis represents the distance in the direction of the optical axis O, and the vertical axis represents the image height (angle of view). In addition, the solid line in Figure 2B represents the field curvature in the tangential plane, and the dotted line represents the field curvature in the sagittal plane. Thus, in the imaging lens system 11 of Example 1, the distance deviation in the direction of the optical axis O of each field curvature is small, and the field curvature is corrected to an appropriate range.

[0056] Figure 2C shows the distortion aberration of the imaging lens system 11 of Example 1. In Figure 2C, the horizontal axis represents the ratio in the optical axis O direction, and the vertical axis represents the field of view (image height). As shown above, the imaging lens system 11 of Example 1 has a small ratio in the optical axis O direction, and the distortion aberration is corrected to an appropriate range.

[0057] [Example 2] Figure 3 is a cross-sectional view showing the configuration of the imaging lens system 11 of the camera module 10 in Embodiment 2.

[0058] The fourth lens L4 has an aspherical lens surface S8 with positive curvature and a convex shape towards the object side, and an aspherical lens surface S9 with positive curvature and a concave shape towards the image side. The fourth lens L4 is a plastic lens with positive power.

[0059] The sixth lens L6 has an aspherical lens surface S12 with positive curvature and a convex shape on the object side, and an aspherical lens surface S13 with positive curvature and a concave shape on the image side. The sixth lens L6 is a positive lens with positive power and is a meniscus-shaped plastic lens.

[0060] The configuration of the imaging lens system 11 in Example 2 is the same as in Example 1, except for the configurations of the fourth lens L4 and the sixth lens L6 described, so the explanation is omitted. Also, the configuration of the camera module 10 in Example 2 is the same as in Example 1, so the explanation is omitted. This Example 2 differs from Example 1 in lens data, etc., as follows.

[0061] Table 4 shows the lens data for each lens surface of the imaging lens system 11 in Example 2. The lens data in Table 4 shows data for the same items as in Table 1.

[0062] [Table 4]

[0063] Table 5 shows the aspheric coefficients and other parameters used to define the aspherical shape of the aspherical lens surface in the imaging lens system 11 of Example 2. Table 5 shows the same values ​​for the same items as in Table 2.

[0064] [Table 5]

[0065] Table 6 shows the characteristic values ​​for the imaging lens system 11 of Example 2, as shown in Tables 4 and 5, etc., for the same items as shown in Table 3, which is the characteristic value for Example 1.

[0066] [Table 6]

[0067] Figure 4A shows the spherical aberration of the imaging lens system 11 of Example 2, Figure 4B shows the field curvature of the imaging lens system 11 of Example 2, and Figure 4C shows the distortion aberration of the imaging lens system 11 of Example 2. Since Figures 4A to 4C show graphs for the same items as Figures 2A to 2C, the explanation for each aberration diagram is the same and will be omitted.

[0068] [Example 3] Figure 5 is a cross-sectional view showing the configuration of the imaging lens system 11 of the camera module 10 in Embodiment 3.

[0069] The sixth lens L6 has an aspherical lens surface S12 with positive curvature and a convex shape on the object side, and an aspherical lens surface S13 with positive curvature and a concave shape on the image side. The sixth lens L6 is a positive lens with positive power and is a meniscus-shaped plastic lens. The configuration of the imaging lens system 11 in Example 3 is the same as in Example 1, except for the configuration of the sixth lens L6 described, so its description is omitted. Also, the configuration of the camera module 10 in Example 3 is the same as in Example 1, so its description is omitted. This Example 3 differs from Example 1 in the following ways regarding lens data, etc.

[0070] Table 7 shows the lens data for each lens surface of the imaging lens system 11 in Example 3. The lens data in Table 7 shows data for the same items as in Table 1.

[0071] [Table 7]

[0072] Table 8 shows the aspheric coefficients and other parameters used to define the aspherical shape of the aspherical lens surface in the imaging lens system 11 of Example 3. Table 8 shows the same values ​​for the same items as in Table 2.

[0073] [Table 8]

[0074] Table 9 shows the characteristic values ​​for the imaging lens system 11 of Example 3, as shown in Tables 7 and 8, etc., for the same items as shown in Table 3, which is the characteristic value for Example 1.

[0075] [Table 9]

[0076] Figure 6A shows the spherical aberration of the imaging lens system 11 of Example 3, Figure 6B shows the field curvature of the imaging lens system 11 of Example 3, and Figure 6C shows the distortion aberration of the imaging lens system 11 of Example 3. Since Figures 6A to 6C show graphs for the same items as Figures 2A to 2C, the explanation for each aberration diagram is the same and will be omitted.

[0077] [Example 4] Figure 7 is a cross-sectional view showing the lens configuration of the imaging lens system 11 of the camera module 10 of Embodiment 4. As shown in Figure 7, Embodiment 4 consists of seven lenses. The imaging lens system 11 of Embodiment 7 comprises, in the order of the optical axis O direction from the object side toward the image side, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, and a seventh lens L7.

[0078] Furthermore, the imaging lens system 11 includes a front lens group that determines the angle of view characteristics, etc., through the first lens L1 and the second lens L2. In addition, the imaging lens system 11 has a front lens group and a rear lens group that contributes to brightness, light-gathering characteristics, etc., through the third lens L3, fourth lens L4, fifth lens L5, sixth lens L6, and seventh lens L7, flanking the optical aperture 1.

[0079] The first lens L1 has a lens surface S1 which is the object side of a spherical surface with positive curvature and a convex shape toward the object, facing the object, and a lens surface S2 which is the image side of a spherical surface with positive curvature and a concave shape toward the image. The first lens L1 is a negative lens with negative power and is a meniscus-shaped glass lens.

[0080] The second lens L2 has an aspherical lens surface S3 with positive curvature and a convex shape towards the object side, and an aspherical lens surface S4 with positive curvature and a concave shape towards the image side. The second lens L2 is a negative lens with negative power and is a meniscus-shaped plastic lens.

[0081] The optical diaphragm 1 (STOP) has an opening that allows light rays to pass through the optical diaphragm surface S5, and the amount of light rays is set by the diameter of the opening. The optical diaphragm 1 is made of a non-transparent material and has a thin shape.

[0082] The third lens L3 has a spherical lens surface S6 with positive curvature that is convex towards the object side, and a spherical lens surface S7 with negative curvature that is convex towards the image side. The third lens, L3, is a positive lens with positive power and is made of glass.

[0083] The fourth lens L4 has an aspherical lens surface S8 with positive curvature and a convex shape towards the object side, and an aspherical lens surface S9 with positive curvature and a concave shape towards the image side. The fourth lens L4 is a plastic lens with positive power.

[0084] Furthermore, the lens surface S8 has a convex shape towards the object in the paraxial region passing through the optical axis O within the effective image circle diameter, and a concave shape in the edge region. In other words, the lens surface S8 has an inflection point IP8.

[0085] Furthermore, the lens surface S9 has a concave shape on the image side in the paraxial portion passing through the optical axis O within the effective image circle diameter, and a convex shape in the edge portion. In other words, the lens surface S8 has an inflection point IP9.

[0086] Thus, the fourth lens L4, by having an inflection point, corrects spherical aberration, coma aberration, etc., that occur at bright Fno. Furthermore, even if the first lens L1 is small, the effective image circle diameter (image height) can be secured. The fourth lens L4 may have at least one of the inflection point IP8 on the lens surface S8 and the inflection point IP9 on the lens surface S9.

[0087] The fifth lens L5 has an aspherical lens surface S10 with negative curvature and a concave shape on the object side, and an aspherical lens surface S11 with negative curvature and a convex shape on the image side. The fifth lens L5 is a plastic lens with positive power.

[0088] Furthermore, the lens surface S10 has a concave shape towards the object side in the paraxial portion passing through the optical axis O within the effective image circle diameter, and a convex shape in the edge portion. In other words, the lens surface S10 has an inflection point IP10.

[0089] Furthermore, the lens surface S11 has a convex shape towards the image side in the paraxial portion passing through the optical axis O, and a concave shape in the edge portion, within the effective image circle diameter. In other words, the lens surface S11 has an inflection point IP11.

[0090] Thus, the fifth lens L5 corrects spherical aberration, coma aberration, etc. that occur at bright Fno by having an inflection point. Furthermore, even if the first lens L1 is small, the effective image circle diameter (image height) can be secured. The fifth lens L5 may have at least one of the inflection point IP10 on the lens surface S10 and the inflection point IP11 on the lens surface S11. In addition, the fifth lens L5 may have at least one of the inflection points IP8 and IP9 of the fourth lens L4, and the inflection points IP10 and IP11 of the fifth lens L5.

[0091] The sixth lens L6 has an aspherical lens surface S12 with positive curvature and a convex shape on the object side, and an aspherical lens surface S13 with positive curvature and a concave shape on the image side. The sixth lens L6 is a negative lens with negative power and is a meniscus-shaped plastic lens.

[0092] In a seven-lens configuration, the lens surface S13, which is the image side of the sixth lens L6 (the second lens from the image side), does not have an inflection point and has a stronger negative power from the center to the edge. In other words, the negative power of the lens surface S13 is stronger at the edge than at the center.

[0093] The concave image side (lens surface S13) of the sixth lens L6 transmits light rays from the fourth lens L4 and the fifth lens L5, ensuring a good peripheral illumination ratio at the periphery of the image sensor 12 and preventing vignetting.

[0094] The seventh lens L7 has an aspherical lens surface S14 with positive curvature and a convex shape on the object side, and an aspherical lens surface S15 with positive curvature and a concave shape on the image side. The sixth lens L6 is a positive lens with positive power and is a meniscus-shaped plastic lens.

[0095] In a seven-lens configuration, the lens surface S14 of the seventh lens L7, which is the closest lens to the first image sensor 12 from the image side, has no inflection point and possesses a strong positive power where light rays converge from the center to the edge. In other words, the positive power of the lens surface S14 is stronger at the edge than at the center.

[0096] The concave image side (lens surface S13) of the sixth lens L6 and the convex object side (lens surface S14) of the seventh lens L7, through which light rays from the fourth lens L4 and fifth lens L5 pass, can improve the principal ray incidence angle (CRA) to the image sensor 12. Therefore, when light rays are incident on the bandpass filter 14 installed between the seventh lens L7 and the image sensor 12, the short-wavelength shift of the transmitted wavelength can be suppressed and transmittance can be ensured.

[0097] The first lens L1 is a glass lens with excellent weather resistance, capable of withstanding natural outdoor environments such as sunlight, temperature, humidity, and rain. The lens surface S1 of the first lens L1 may also be coated with a water-repellent or water-resistant coating. The third lens L3 is a glass lens capable of suppressing focus fluctuations due to changes in ambient temperature, etc.

[0098] Furthermore, the second lens L2, fourth lens L4, fifth lens L5, sixth lens L6, and seventh lens L7 are made of plastic to achieve weight reduction, cost reduction, and impact resistance. At least one of the second lens L2, fourth lens L4, fifth lens L5, sixth lens L6, and seventh lens L7 may be a plastic lens.

[0099] Thus, the imaging lens system 11 comprises, in order from the object side to the image side, a first lens L1 having negative power with its image side concave toward the image side, a second lens L2 having negative power, a third lens L3 having positive power with its object side convex toward the object side and its image side convex toward the image side, a fourth lens L4, a fifth lens L5, a sixth lens L6 with its image side concave toward the image side, and a seventh lens L7 having positive power with its object side convex toward the object side. By having inflection points on at least one surface between the object side and the image side of the fourth lens L4, and between the object side and the image side of the fifth lens L5, the imaging lens system can provide a bright imaging lens system with a wide angle of view and high resolution over a wide temperature range. Furthermore, by having a sixth lens L6 with a concave image side and a seventh lens L7 with a convex object side, the imaging lens system 11 can provide an imaging lens system with telecentricity.

[0100] Furthermore, each lens surface of the first lens L1 to the seventh lens L7 may have a curved surface at least for the effective image circle diameter passing through the optical axis O, similar to the lens surface S2 of the first lens L1, and the edges may be flat.

[0101] The bandpass filter 14 (BPF) of the camera module 10 is a filter that allows only light rays of a predetermined wavelength to pass through. For example, the bandpass filter 14 transmits light rays in the wavelength range of 750 nm to 1000 nm. The bandpass filter 14 has a BPF surface S16 and a BPF surface S17.

[0102] The cover glass 13 (CG) of the camera module 10 is a glass plate for protecting the image sensor 12. The cover glass 13 has a CG surface S18 and a CG surface S19. The image sensor 12 (IMG) is an element capable of capturing light rays (images) in the wavelength range of 750 nm to 1000 nm, and has an imaging surface S20.

[0103] Thus, the camera module 10 comprises an imaging lens system 11, an optical aperture 1, a bandpass filter 14, a cover glass 13, and an image sensor 12, with each edge fixed to the housing (barrel, etc.) of the camera module 10 or the imaging lens system 11 by flanges or the like. The optical aperture 1 is installed integrally with the imaging lens system 11, but it is not an essential component of the imaging lens system 11. The imaging lens system 11 may also be provided with flanges or the like that substitute for the function of an aperture diaphragm and thus serve as the optical aperture 1.

[0104] Furthermore, the optical aperture 1 is installed between the second lens L2 and the third lens L3, but it may also be installed between the third lens L3 and the fourth lens L4, or at any position between the first lens L1 and the seventh lens L7. By installing the optical aperture 1, the imaging lens system 11 can further reduce the front element diameter of the first lens L1. Moreover, the imaging lens system 11 may have multiple optical apertures.

[0105] Furthermore, although the camera module 10 includes a bandpass filter 14 between the seventh lens L7 and the cover glass 13, it may also be placed between the cover glass 13 and the image sensor 12, i.e., on the object side of the image sensor 12. Moreover, the camera module 10 does not necessarily need the cover glass 13.

[0106] Table 10 shows the lens data for each lens surface of the imaging lens system 11 in Example 4. Except for the seventh lens L7, Table 10 shows data for the same items as in Table 1.

[0107] [Table 10]

[0108] Table 11 shows the aspheric coefficients and other parameters used to define the aspherical shape of the aspherical lens surface in the imaging lens system 11 of Example 4. Table 11 shows the same values ​​for the same items as in Table 2, except for lens surfaces S14 and S15 of the seventh lens L7.

[0109] [Table 11]

[0110] Table 12 shows the characteristic values ​​for the imaging lens system 11 of Example 4, as shown in Tables 10 and 11.

[0111] [Table 12]

[0112] In the imaging lens system 11, f represents the focal length of the entire lens system from the first lens L1 to the seventh lens L7. f7 represents the focal length of the seventh lens L7. bf represents the distance on the optical axis O from the image-side lens surface S15 of the seventh lens L7 to the imaging surface S20 of the image sensor 12. All other values ​​are shown as those for the same items as shown in Table 3, which is the characteristic value of Example 1.

[0113] Figure 8A shows the spherical aberration of the imaging lens system 11 of Example 4, Figure 8B shows the field curvature of the imaging lens system 11 of Example 4, and Figure 8C shows the distortion aberration of the imaging lens system 11 of Example 4. Since Figures 8A to 8C show graphs for the same items as Figures 2A to 2C, the explanation for each aberration diagram is the same and will be omitted.

[0114] [Example 5] Figure 9 is a cross-sectional view showing the configuration of the imaging lens system 11 of the camera module 10 in Example 5. The configuration of the imaging lens system 11 in Example 5 is the same as that of Example 4, so its explanation is omitted. Similarly, the configuration of the camera module 10 in Example 5 is the same as that of Example 4, so its explanation is omitted. This Example 5 differs from Example 4 in lens data, etc., as follows.

[0115] Table 13 shows the lens data for each lens surface of the imaging lens system 11 in Example 5. The lens data in Table 13 shows data for the same items as in Table 10. Also, surfaces marked with an asterisk (*) indicate aspherical lens surfaces. That is, the second lens L2 and the fourth lenses L4 to the seventh lenses L7 are aspherical lenses.

[0116] [Table 13]

[0117] Table 14 shows the aspheric coefficients and other parameters used to define the aspherical shape of the aspherical lens surface in the imaging lens system 11 of Example 5. Table 14 shows the values ​​for the same items as in Table 11.

[0118] [Table 14]

[0119] Table 15 shows the characteristic values ​​for the imaging lens system 11 of Example 5, as shown in Tables 13 and 14, etc., for the same items as shown in Table 12, which is the characteristic value for Example 4.

[0120] [Table 15]

[0121] Figure 10A shows the spherical aberration of the imaging lens system 11 of Example 5, Figure 10B shows the field curvature of the imaging lens system 11 of Example 5, and Figure 10C shows the distortion aberration of the imaging lens system 11 of Example 5. Since Figures 10A to 10C show graphs for the same items as Figures 2A to 2C, the explanation for each aberration diagram is the same and will be omitted.

[0122] [Example 6] Figure 11 is a cross-sectional view showing the configuration of the imaging lens system 11 of the camera module 10 in Embodiment 6.

[0123] The seventh lens L7 has an aspherical lens surface S14 with positive curvature that is convex towards the object side, and an aspherical lens surface S15 with negative curvature that is convex towards the image side. The sixth lens L6 is a positive lens with positive power and is a meniscus-shaped plastic lens. The configuration of the imaging lens system 11 in Example 6 is the same as in Example 4, except for the configuration of the seventh lens L7 described, so its description is omitted. Similarly, the configuration of the camera module 10 in Example 6 is the same as in Example 4, so its description is omitted. This Example 6 differs from Example 4 in the following ways regarding lens data, etc.

[0124] Table 16 shows the lens data for each lens surface of the imaging lens system 11 in Example 6. The lens data in Table 16 shows data for the same items as in Table 10. Also, surfaces marked with an asterisk (*) indicate aspherical lens surfaces. That is, the second lens L2 and the fourth lenses L4 to the seventh lenses L7 are aspherical lenses.

[0125] [Table 16]

[0126] Table 17 shows the aspheric coefficients and other parameters used to define the aspherical shape of the aspherical lens surface in the imaging lens system 11 of Example 6. Table 17 shows the values ​​for the same items as in Table 11.

[0127] [Table 17]

[0128] Table 18 shows the characteristic values ​​for the imaging lens system 11 of Example 6, as shown in Tables 16 and 17, etc., for the same items as shown in Table 12, which is the characteristic value for Example 4.

[0129] [Table 18]

[0130] Figure 12A shows the spherical aberration of the imaging lens system 11 of Example 6, Figure 12B shows the field curvature of the imaging lens system 11 of Example 6, and Figure 12C shows the distortion aberration of the imaging lens system 11 of Example 6. Since Figures 12A to 12C show graphs for the same items as Figures 2A to 2C, the explanation for each aberration diagram is the same and will be omitted.

[0131] [Example 7] Figure 13 is a cross-sectional view showing the configuration of the imaging lens system 11 of the camera module 10 in Example 7. The configuration of the imaging lens system 11 in Example 7 is the same as that of Example 4, so its explanation is omitted. Similarly, the configuration of the camera module 10 in Example 7 is the same as that of Example 4, so its explanation is omitted. This Example 7 differs from Example 4 in lens data, etc., as follows.

[0132] Table 19 shows the lens data for each lens surface of the imaging lens system 11 in Example 7. The lens data in Table 19 shows data for the same items as in Table 10. Also, surfaces marked with an asterisk (*) indicate aspherical lens surfaces. That is, the second lens L2 and the fourth lenses L4 to the seventh lenses L7 are aspherical lenses.

[0133] [Table 19]

[0134] Table 20 shows the aspheric coefficients and other parameters used to define the aspherical shape of the aspherical lens surface in the imaging lens system 11 of Example 7. Table 20 shows the same values ​​for the same items as in Table 11.

[0135] [Table 20]

[0136] Table 21 shows the characteristic values ​​for the imaging lens system 11 of Example 7, as shown in Tables 19 and 20, etc., for the same items as shown in Table 12, which is the characteristic value for Example 4.

[0137] [Table 21]

[0138] Figure 14A shows the spherical aberration of the imaging lens system 11 of Example 7, Figure 14B shows the field curvature of the imaging lens system 11 of Example 7, and Figure 14C shows the distortion aberration of the imaging lens system 11 of Example 7. Since Figures 14A to 14C show graphs for the same items as Figures 2A to 2C, the explanation for each aberration diagram is the same and will be omitted.

[0139] [Summary of conditional expressions] Table 22 summarizes the main characteristic values ​​and calculated related values ​​of the imaging lens system 11 in Examples 1 to 6. The wavelength of the light ray in these examples was 0.94 μm.

[0140] [Table 22]

[0141] The imaging lens system 11 with a 6-lens configuration (Examples 1 to 3) satisfies the following condition (1) when the focal length of the fourth lens L4 is f4. 0.0003≦|1 / f4|≦0.08 ···(1) By satisfying condition (1), the imaging lens system 11 can provide an imaging lens system with a wide angle of view and high resolution over a wide temperature range, in a bright imaging lens system. Furthermore, it is even better if |1 / f4| satisfies 0.0007 ≤ |1 / f4| ≤ 0.0123.

[0142] The imaging lens system 11 with a 7-lens configuration (Examples 4 to 7) satisfies the following condition (2) when the focal length of the 4th lens L4 is f4 and the focal length of the 5th lens L5 is f5. 0.0003≦|1 / f4+1 / f5|≦0.08 ···(2) By satisfying condition (2), the imaging lens system 11 can provide an imaging lens system with a wide angle of view and high resolution over a wide temperature range, in a bright imaging lens system. Furthermore, it is even better if |1 / f4+1 / f5| satisfies 0.0190≦|1 / f4+1 / f5|≦0.0425.

[0143] The imaging lens system 11 satisfies the following condition (3) when the focal length of the third lens L3 is f3 and the focal length of the entire optical system is f. 1.5 ≤ f³ / f ≤ 2.0 ···(3) By satisfying condition (3), the imaging lens system 11 can provide an imaging lens system with a wide angle of view and high resolution over a wide temperature range, while also being bright. Furthermore, it is preferable that f3 / f satisfies the condition 1.70 ≤ f3 / f ≤ 1.91.

[0144] The imaging lens system 11 satisfies the following condition (4), where ttl is the distance from the object-side lens surface S1 of the first lens L1 to the imaging surface S20 of the image sensor 12 on the optical axis O, and f is the focal length of the entire optical system. 5 ≤ ttl / f ≤ 6 ···(4) By satisfying condition (4), the imaging lens system 11 can provide an imaging lens system with a wide angle of view and high resolution over a wide temperature range, while also being bright. Furthermore, it is preferable that ttl / f satisfies 5.56 ≤ ttl / f ≤ 5.64.

[0145] [Differentiation] The present invention is not limited to the embodiments described above, and includes various other modifications. For example, the embodiments described above are described in detail to make the present invention easier to understand, and are not necessarily limited to those having all the configurations described.

[0146] Furthermore, it is possible to replace parts of the configuration of one embodiment with parts of the configuration of another embodiment, and it is also possible to add parts of the configuration of another embodiment to the configuration of one embodiment. In addition, it is possible to add, delete, or replace parts of the configuration of each embodiment with parts of other configurations. [Embodiment 2] Figure 15 shows the configuration of an imaging device 50 equipped with the imaging lens system 11 of Embodiment 1. As shown in the figure, the imaging device 50 according to the embodiment includes a camera module 10 that houses the imaging lens system 11 and an image sensor 12 etc. in a housing (not shown), a control unit 52, and a storage unit 54.

[0147] The control unit 52 controls the camera module 10 and processes the electrical signals output from the image sensor 12 of the camera module 10. This control unit 52 may be composed of, for example, a processor unit (PU), RAM, ROM, etc. The control unit 52 may also include one or more processors.

[0148] The processor may include a general-purpose processor that loads a specific program and executes a specific function, and a dedicated processor specialized for a specific process. The dedicated processor may include an application-specific integrated circuit (IC). An application-specific integrated circuit (ASIC) is also called an application-specific integrated circuit (ASIC). The processor may also include a programmable logic device (Programmable Logic Device). A programmable logic device (PLD) is also called a Programmable Logic Device (PLD). A PLD may include a Field-Programmable Gate Array (FPGA). The control unit 52 may be either a System-on-a-Chip (SoC) or a System-in-a-Package (SiP) in which one or more processors cooperate.

[0149] The storage unit 54 stores various information or parameters related to the operation of the imaging device 50. The storage unit 54 may be composed of, for example, a semiconductor memory. The storage unit 54 may function as a work memory for the control unit 52. The storage unit 54 may store captured images. The storage unit 54 may store various information or parameters for the control unit 52 to perform detection processing and control based on the captured images. The storage unit 54 may be included in the control unit 52.

[0150] As mentioned above, the camera module 10 captures an image of a subject (object) formed via the imaging lens system 11 using the image sensor 12, and outputs the captured image. The image captured by the camera module 10 is also called the captured image.

[0151] The image sensor 12 may be composed of, for example, a CMOS (Complementary Metal Oxide Semiconductor) image sensor or a CCD (Charge Coupled Device). The image sensor 12, positioned at the focal point of the imaging lens system 11, has an imaging surface in which multiple pixels are arranged. Each pixel outputs a signal that is specified by current or voltage according to the amount of incident light. The signal output by each pixel is also called imaging data.

[0152] The imaging data may be read out by the camera module 10 for all pixels and taken into the control unit 52 as an image. The image obtained by reading out all pixels is also called the maximum image. The imaging data may be read out by the camera module 10 for some pixels and taken into the image. In other words, the imaging data may be read out from pixels within a predetermined acquisition range. The imaging data read out from pixels within a predetermined acquisition range may be taken into the image. The predetermined acquisition range may be set by the control unit 52. The camera module 10 may obtain the predetermined acquisition range from the control unit 52. The image sensor 12 may capture an image within a predetermined acquisition range from the subject image formed via the imaging lens system 11. Alternatively, the imaging device 50 (imaging camera) may be an imaging system in which the camera module 10 is a separate unit connected by cables or the like. [Embodiment 3] Figure 16 is a schematic diagram of a vehicle 40 equipped with an in-vehicle system that includes an imaging device 50 comprising an imaging lens system according to Embodiment 1 or Embodiment 2 and an image sensor that converts the light focused through the lens into an electrical signal.

[0153] As shown in Figure 16, the vehicle 40, which is a motor vehicle that travels day and night, is equipped with tires, steering, etc., for driving. The mobile vehicle 40 is equipped with an imaging device 50 that can obtain bright, high-resolution images corresponding to a wide field of view. The vehicle 40 is also equipped with an information processing device 42, a display device 43, etc.

[0154] Figure 16 shows several example arrangements illustrating the mounting positions of the imaging devices 50 in the vehicle 40. For example, the first imaging device 50a, which is one of the imaging devices 50, may be placed on or near the front bumper as a camera that monitors the area in front of the vehicle 40 while it is in motion. The second imaging device 50b, which is another imaging device 50 that monitors the area in front, may be placed near the rearview mirror inside the vehicle 40. The third imaging device 50c may be placed on the dashboard or inside the instrument panel, etc., as a camera that monitors the driver's driving conditions. The fourth imaging device 50d may be installed at the rear of the vehicle 40 for use as a rear monitor.

[0155] The first imaging device 50a and the second imaging device 50b can be called front cameras. The third imaging device 50c can be called an in-camera. The fourth imaging device 50d can be called a rear camera. The imaging device 50 is not limited to these, and can be installed in various positions, such as a left-side camera that images the left rear side and a right-side camera that images the right rear side, and is an imaging device that can provide a wide field of view with few blind spots. In this way, the imaging lens system 11 within the imaging device 50 can be installed in various positions on the vehicle 40.

[0156] Figure 17 is a diagram showing the configuration of a vehicle 40 on which an in-vehicle system 41 is mounted, which includes an imaging device 50 comprising an imaging lens system 11 according to Embodiment 1 or Embodiment 2 and an imaging sensor 12 that converts the light focused through thereon into an electrical signal.

[0157] As shown in Figure 17, the imaging device 50 mounted on the vehicle 40 as an automobile can also be called an on-board camera and can be installed in various locations on the vehicle 40. Furthermore, the on-board system 41 equipped with the imaging device 50 etc. mounted on the vehicle 40 as an automobile is also a mobile system equipped with the imaging device 50 etc. mounted on a mobile body. In other words, the mobile body is not limited to the vehicle 40 as an automobile, but includes, for example, a moving bicycle, motorcycle, wheelchair, train, drone, helicopter, airplane, ship, etc.

[0158] As shown in Figure 17, the image signal of the captured image captured by the imaging device 50 is output to the information processing device 42, display device 43, etc. of the vehicle 40 via a cable or bus, etc. Furthermore, the image signal of the captured image may be output to the information processing device, display device, etc. of the control center via wireless or network, etc. The in-vehicle system 41 comprises at least the information processing device 42 and the imaging device 50. The in-vehicle system 41 may also comprise the information processing device 42, the imaging device 50, and the display device 43, etc.

[0159] The information processing device 42 of the vehicle 40 acquires the captured image output from the camera module 10 of the imaging device 50 and processes the image signal of the captured image. The information processing device 42 may also process the captured images acquired by the first imaging device 50a and the second imaging device 50b, which are imaging devices 50 as shown in Figure 16, by combining them. The information processing device 42 may be composed of, for example, a processor unit (PU), RAM, ROM, etc.

[0160] The information processing device 42 recognizes various objects in the captured image, such as people (including the driver of the vehicle 40 captured by the in-camera), other vehicles, other moving objects, animals, roads, and road signs, and generates recognition information such as images of the objects, their type, location, and speed of movement.

[0161] The captured images may be images of the vehicle 40 in the direction of movement, or one or more images that meet predetermined conditions, for example, one image when the vehicle 40 is traveling at a predetermined speed or higher, and multiple images when it is traveling at a speed lower than that.

[0162] The information processing device 42 includes devices that assist the driver in driving. For example, the information processing device 42 includes, but is not limited to, a navigation device, a collision damage mitigation braking device, a distance control device, and a lane departure warning device.

[0163] The display device 43 displays images and other recognition information processed and output by the information processing device 42 as an output device, but it may also notify audio, which is recognition information corresponding to the images and other recognition information, using an audio output device as an output device.

[0164] Furthermore, the display device 43 may employ, but is not limited to, a liquid crystal display (LCD), an organic electro-luminescence (EL) display, or an inorganic EL display. The display device 43 can also directly receive image signals, such as captured images output from an imaging device 50 that captures images from a position difficult for the driver to see, such as a rear camera, for example, a fourth imaging device 50d, and display the captured images to the driver or other occupants. The display device 43 may also be an output device equipped with an audio output device that outputs sound, etc., based on the image signal.

[0165] It should be noted that the present invention is not limited to the embodiments described above, and can be modified as appropriate without departing from the spirit of the invention. For example, the applications of the imaging lens system 11 of the present invention are not limited to in-vehicle cameras, but can also be used in other applications such as fixed surveillance cameras, digital cameras, and cameras mounted on small electronic devices such as portable mobile phones.

[0166] Furthermore, the present invention includes various embodiments other than those described above. For example, the above-described embodiments are explained in detail to make the present invention easier to understand, and are not necessarily limited to those having all the configurations described.

[0167] Furthermore, the present invention allows for the replacement of parts of the configuration of one embodiment with the configuration of another embodiment, and also allows for the addition of configurations from other embodiments to the configuration of one embodiment. In addition, the present invention allows for the addition, deletion, and replacement of parts of the configuration of each embodiment with other configurations. [Explanation of Symbols]

[0168] 1: Optical aperture (STOP), 10: Camera module, 11: Imaging lens system, 12: Image sensor (IMG), 13: Cover glass (CG), 14: Bandpass filter (BPF), 40: Vehicles, 41: In-vehicle systems, 42: Information processing equipment, 43:Display device, 50, 50a, 50b, 50c, 50d: Imaging devices (imaging cameras, in-vehicle cameras) 52: Control unit, 54: Memory section, L1: First lens, L2: Second lens, L3: Third lens, L4: Fourth lens, L5: Fifth lens, L6: 6th lens, L7: 7th lens, S1~S4, S6~S15: Lens surface, S5: Optical aperture surface, S16, S17: BPF surface, S18, S19: CG surface, S20: Imaging surface IP8, IP9, IP10, IP11: Inflection point.

Claims

1. Starting from the object side and moving towards the image side, A first lens having negative power with its image side facing the image side as a concave surface, The second lens possesses negative power, A third lens having positive power, with the object side facing the object and the image side facing the image, The fourth lens, A fifth lens with its image side facing the image side, A sixth lens having positive power with the side surface of the object facing the object, In an imaging lens system having, The imaging lens system wherein the fourth lens has an inflection point on at least one of its surfaces, between the object surface and the image surface.

2. In the imaging lens system described in claim 1, An imaging lens system that satisfies the following condition (1) when the focal length of the fourth lens is f4. 0.0003≦|1 / f4|≦0.08...(1)

3. Starting from the object side and moving towards the image side, A first lens having negative power with its image side facing the image side as a concave surface, The second lens possesses negative power, A third lens having positive power, with the object side facing the object and the image side facing the image, The fourth lens, The fifth lens, A sixth lens with its image side facing the image side, A seventh lens having positive power with the side surface of the object facing the object, In an imaging lens system having, An imaging lens system having an inflection point on at least one surface between the object side and the image side of the fourth lens, and between the object side and the image side of the fifth lens.

4. In the imaging lens system described in claim 3, An imaging lens system that satisfies the following condition (2) when the focal length of the fourth lens is f4 and the focal length of the fifth lens is f5. 0.0003≦|1 / f4+1 / f5|≦0.08...(2)

5. In the imaging lens system according to claim 1 or claim 3, The image lens system is such that the second lens from the image side does not have an inflection point and has stronger negative power towards the edge than towards the center.

6. In the imaging lens system according to claim 1 or claim 3, The image lens system is such that the object side of the first lens from the image side does not have an inflection point and has stronger positive power towards the edge than towards the center.

7. In the imaging lens system according to claim 1 or claim 3, An imaging lens system that satisfies the following condition (3), where f is the focal length of the entire optical system and f3 is the focal length of the third lens. 1.5 ≤ f³ / f ≤ 2.0 ... (3)

8. In the imaging lens system according to claim 1 or claim 3, An imaging lens system that satisfies the following condition (4), where ttl is the distance from the object-side lens surface of the first lens to the imaging surface of the image sensor on the optical axis, and f is the focal length of the entire optical system. 5 ≤ ttl / f ≤ 6 ... (4)

9. In the imaging lens system according to claim 1 or claim 3, An imaging lens system with an F-number in the range of 1.5 to 1.

10. In the imaging lens system according to claim 1 or claim 3, An imaging lens system having an aperture between the second lens and the third lens.

11. In the imaging lens system according to claim 1 or claim 3, An imaging lens system with a horizontal field of view in the range of 120° to 160°.

12. The imaging lens system according to any one of claims 1 to 4, A camera module comprising an image sensor that converts light collected through the aforementioned imaging lens system into an electrical signal.

13. In the camera module according to claim 12, The aforementioned image sensor is a camera module that captures light rays in the wavelength range of 750 nm to 1000 nm.

14. An imaging device comprising: a camera module according to claim 12; a control unit for controlling the camera module; and a storage unit for storing information for the control unit to perform control.

15. An in-vehicle system comprising a camera module according to claim 12, and an information processing device that recognizes an object in an image captured by the camera module and generates recognition information.

16. A mobile body comprising: a camera module according to claim 12; an information processing device that recognizes an object in an image captured by the camera module and generates recognition information; and an output device that outputs the recognition information.

Images