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

Abstract

We can provide an imaging lens system with a wide field of view and high resolution, offering brightness and resolution. [Solution] In an imaging lens system consisting of a front lens group, an optical aperture, and a rear lens group, arranged in order from the object side to the image side, the front lens group consists of a first lens with negative power in a meniscus shape, a second lens with negative power, and a third lens with positive power, and the rear lens group consists of a fourth lens with positive power whose object-side lens surface is concave, a fifth lens with positive power, a sixth lens with negative power, and a seventh lens with positive power, and when the radius of curvature of the image-side lens surface of the third lens is L3R2 and the radius of curvature of the object-side lens surface of the fourth lens is L4R1, the following condition is satisfied: -1.5 < -(L3R2 + L4R1) / (L3R2 - L4R1) < -0.8.

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, for imaging lens systems for in-vehicle use, lenses corresponding to a wide viewing angle have been required. Imaging lens systems for in-vehicle use are used in in-vehicle cameras, and for example, are used for view applications such as front, back, and side, and sensing applications to ensure safety when driving an automobile.

[0003] The imaging lens system of an in-vehicle camera is required to be an imaging lens system having an extremely wide viewing angle and higher resolution and brightness.

[0004] However, in a configuration of a bright wide-angle imaging system, that is, a configuration with a large aperture, spherical aberration and coma aberration occur, so there is a problem of achieving both a large aperture and high-resolution imaging performance.

[0005] Patent Document 1 describes an imaging lens system in an in-vehicle camera.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] The present invention has been made in view of the above, and provides an imaging lens system having high resolution and brightness corresponding to a wide viewing angle.

Means for Solving the Problems

[0008] In an imaging lens system consisting of a front lens group, an optical aperture, and a rear lens group, arranged in order from the object side to the image side, the front lens group is composed of a first lens with negative power and a meniscus shape, a second lens with negative power, and a third lens with positive power, and the rear lens group is composed of a fourth lens with positive power and a concave lens surface on the object side, a fifth lens with positive power, a sixth lens with negative power, and a seventh lens with positive power, and when the radius of curvature of the image-side lens surface of the third lens is L3R2 and the radius of curvature of the object-side lens surface of the fourth lens is L4R1, the following condition is satisfied: -1.5 < -(L3R2 + L4R1) / (L3R2 - L4R1) < -0.8. [Effects of the Invention]

[0009] This invention can provide an imaging lens system that is bright, has high resolution, and is compatible with a wide field of view. [Brief explanation of the drawing]

[0010] [Figure 1] This is a cross-sectional view of the imaging lens system according to Example 1. [Figure 2] This is an aberration diagram of the imaging lens system according to Example 1. [Figure 3] This is a lateral aberration diagram of the imaging lens system according to Example 1. [Figure 4] This figure shows the eccentricity sensitivity of the imaging lens system according to Example 1. [Figure 5] This is a cross-sectional view of the imaging lens system according to Example 2. [Figure 6] This is an aberration diagram of the imaging lens system according to Example 2. [Figure 7] This is a lateral aberration diagram of the imaging lens system according to Example 2. [Figure 8] This figure shows the eccentricity sensitivity of the imaging lens system according to Example 1. [Figure 9] This is a cross-sectional view of the imaging lens system according to Example 3. [Figure 10] This is an aberration diagram of the imaging lens system according to Example 3. [Figure 11]It is a lateral aberration diagram of the imaging lens system according to Example 3. [Figure 12] It is a diagram showing the decentering sensitivity of the imaging lens system according to Example 3. [Figure 13] It is a cross-sectional view of the imaging lens system according to Example 4. [Figure 14] It is an aberration diagram of the imaging lens system according to Example 4. [Figure 15] It is a lateral aberration diagram of the imaging lens system according to Example 4. [Figure 16] It is a diagram showing the decentering sensitivity of the imaging lens system according to Example 4. [Figure 17] It is a cross-sectional view of the imaging lens system according to Example 5. [Figure 18] It is an aberration diagram of the imaging lens system according to Example 4. [Figure 19] It is a lateral aberration diagram of the imaging lens system according to Example 4. [Figure 20] It is a diagram showing the decentering sensitivity of the imaging lens system according to Example 4. [Figure 21] It is a configuration diagram of an imaging device including an imaging lens system. [Figure 22] It is a schematic diagram of a vehicle including an imaging device. [Figure 23] A configuration diagram of a vehicle including an imaging device.

Modes for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings and the like. In the drawings and descriptions of this embodiment, functionally identical elements may sometimes be denoted by the same numbers. Note that the following descriptions show embodiments based on principles, but these are for understanding this embodiment and are not used to interpret this embodiment restrictively. The descriptions of this embodiment are merely typical examples and do not limit the scope of the claims or application examples in any sense.

[0012] [[ID=4)]] 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.

[0013] 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 Build 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.

[0014] In other words, 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, let's describe the fundamental embodiment of the present invention.

[0015] The imaging lens system 11 satisfies the following condition (1) when the radius of curvature of the image-side lens surface S6 of the third lens L3 is defined as L3R2 and the radius of curvature of the object-side lens surface S9 of the fourth lens L4 is defined as L4R1.

[0016] -1.5<-(L3R2+L4R1) / (L3R2-L4R1)<-0.8 ···(1) By satisfying this condition (1), the camera module 10 can effectively correct spherical aberration and coma aberration, satisfy resolution performance requirements, and obtain bright, high-resolution capabilities that correspond to a wide field of view.

[0017] Furthermore, the imaging lens system 11 should satisfy the following condition (2) when the focal length of the third lens L3 is f3 and the focal length of the fourth lens L4 is f4.

[0018] 0.8 <f3 / f4<1.25 ···(2) By satisfying this condition (2), the imaging lens system 11 can set the power distribution between the third lens L3 and the fourth lens L4 within a predetermined range, and the camera module 10 can effectively correct coma aberration.

[0019] Furthermore, the imaging lens system 11 should satisfy the following condition (3), where Ze3 is the sag amount at the edge of the effective surface of the image-side lens surface S6 of the third lens L3, and TTL is the total optical distance along the optical axis Z from the object-side lens surface S1 of the first lens L1 to the image-forming surface S21 of the image sensor 12.

[0020] 0.0001 <Ze3 / TTL<0.010 ···(3) By satisfying condition (3), the imaging lens system 11 can set the power of the image-side lens surface S6 of the third lens L3 to an appropriate range, and the camera module 10 can effectively correct spherical aberration and coma aberration.

[0021] Furthermore, the imaging lens system 11 should satisfy the following condition (4), where Ze4 is the sag amount of the edge of the effective surface of the object-side lens surface S9 of the fourth lens L4, and TTL is the total optical distance along the optical axis Z from the object-side lens surface S1 of the first lens L1 to the image-forming surface S21 of the image sensor 12.

[0022] -0.02 <Ze4 / TTL<-0.01 ···(4) By satisfying this condition (4), the imaging lens system 11 can set the power of the object-side lens surface S9 of the fourth lens L4 to an appropriate range, and the camera module 10 can effectively correct spherical aberration and coma aberration.

[0023] As an embodiment, the imaging lens system 11 of the camera module 10 will be described as an example including specific numerical values.

[0024] [Example 1] Figure 1 is a cross-sectional view showing the configuration of the imaging lens system 11 of the camera module 10 of Embodiment 1. As shown in Figure 1, the imaging lens system 11 of Embodiment 1 comprises 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, in the order of the optical axis Z direction from the object side to the image side.

[0025] Furthermore, the imaging lens system 11 has a front lens group that determines the angle of view characteristics, etc., through the first lens L1, the second lens L2, and the third lens L3. 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 fourth lens L4, the fifth lens L5, the sixth lens L6, and the seventh lens L7, flanking the optical aperture 1.

[0026] The first lens L1 has a spherical lens surface S1 with positive curvature that is convex towards the object side, and a spherical lens surface S2 with negative curvature that is concave towards the image side. The first lens L1 is a negative lens with a negative refractive power (negative power) that diffuses light rays, and is a meniscus-shaped glass lens with a thicker edge than the center.

[0027] The second lens L2 has an aspherical lens surface S3 with positive curvature and a convex shape towards the object, and an aspherical lens surface S4 with negative curvature and a concave shape towards the image. The second lens L2 is a meniscus-shaped glass lens with a negative refractive power (negative power) that diffuses light rays, and is thicker at the edges than at the center.

[0028] The third lens L3 has an aspherical lens surface S5 with positive curvature that is convex towards the object side, and an aspherical lens surface S6 with positive curvature that is convex towards the image side. The radius of curvature of lens surface S6 is much longer than the radius of curvature of lens surface S5, and also longer than the radius of curvature of lens surface S9 of the fourth lens L4, which will be described later. Lens surface S6 corrects coma aberration with a gentle curve (almost flat curve). The third lens L3 is a positive glass lens that has a positive refractive power (positive power) that converges light rays, and is thicker towards the center than towards the edges.

[0029] The optical diaphragm 1 (STOP) has an opening that allows light rays to pass through the optical diaphragm surfaces S7 and S8, and the amount of light rays is set by the diameter of the opening. The optical diaphragm 1 has a thin, non-transparent shape.

[0030] The fourth lens L4 has an aspherical lens surface S9 with negative curvature and a concave shape on the object side, and an aspherical lens surface S10 with positive curvature and a convex shape on the image side. The concave lens surface S9 corrects coma aberration. The fourth lens L4 is a positive glass lens that has positive refractive power (positive power) that converges light rays, and is thicker on the center side than on the edges. In addition, the lens surface S6 of the third lens L3 and the lens surface S9 of the fourth lens L4 form an air lens, correcting spherical aberration and coma aberration.

[0031] The fifth lens L5 has a spherical lens surface S11 with positive curvature that is convex towards the object side, and a spherical lens surface S12 with positive curvature that is convex towards the image side. The fifth lens L5 is a positive glass lens that has positive refractive power (positive power) that converges light rays, and is thicker towards the center than towards the edge.

[0032] The sixth lens L6 has a spherical lens surface S13 with negative curvature and a concave shape on the object side, and a spherical lens surface S14 with negative curvature and a concave shape on the image side. The sixth lens L6 is a negative glass lens that has a negative refractive power (negative power) that diffuses light rays, and is thicker at the edges than at the center.

[0033] Furthermore, the image-side lens surface S12 of the fifth lens L5 is bonded to the object-side lens surface S13 of the sixth lens L6 by applying a synthetic resin adhesive or the like, forming a cemented lens with the fifth lens L5 and the sixth lens L6. This cemented lens is a lens that has negative refractive power (negative power) that diffuses light rays. In addition, the area around the joint and edges of the cemented lens may be coated with a solvent-free resin mixed with carbon black or the like. By combining the fifth lens L5 and the sixth lens L6, axial chromatic aberration and lateral chromatic aberration can be corrected, and the cemented surface performs higher-order aberration correction.

[0034] The seventh lens L7 has an aspherical lens surface S15 with positive curvature that is convex towards the object side, and an aspherical lens surface S16 with positive curvature that is convex towards the image side. The seventh lens L7 is a positive glass lens that has a positive refractive power (positive power) that converges light rays, and is thicker on the center side than on the edge side of the lens.

[0035] The first lens L1 to the seventh lens L7 are glass lenses, which can suppress focus fluctuations due to changes in ambient temperature. Alternatively, the first lens L1 to the seventh lens L7 may be plastic lenses. In other words, the imaging lens system 11 may be made of plastic lenses to achieve weight reduction, cost reduction, and impact resistance.

[0036] The Fno (F-number) of the imaging lens system 11 is 1.6. Fno 1.6 is an Fno (F-number) that ensures sufficient light and allows the imaging lens to be bright. It is generally smaller than Fno 2.8, which is considered a dark optical system, and may even be less than 1.6.

[0037] These fourth lens L4 to seventh lens L7 correct 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 1.6) is created.

[0038] Furthermore, each lens surface of the first lens L1 to the seventh lens L7 may have a curved surface at least on the surface passing through the optical axis Z, similar to the lens surface S1 of the first lens L1, and its edges may be flat.

[0039] The IR cut filter 14 (IRCF) is a filter that removes IR (infrared light) from the light ray. The IR cut filter 14 has an IRCF surface S17 and an IRCF surface S18. The cover glass 13 (CG) is a glass plate for protecting the image sensor 12. The cover glass 13 has a CG surface S19 and a CG surface S20. The image sensor 12 (IMG) is an element that forms an image of a light ray (image), and has an imaging surface S21.

[0040] Thus, the camera module 10 comprises an imaging lens system 11, an optical aperture 1, an IR cut filter 14, a cover glass 13, and an image sensor 12, with each edge fixed to the housing of the camera module 10 or the imaging lens system 11 by a flange 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, and the optical aperture 1 is optional. The optical aperture 1 is installed between the third lens L3 and the fourth lens L4, but it may be installed at any position between the first lens L1 and the seventh lens L7. Furthermore, the imaging lens system 11 may have multiple optical apertures.

[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 νd for each surface. The interplanar spacing D(i) is the distance between surfaces S(i) and S(i+1) on the optical axis Z. For example, it indicates that the central thickness on the optical axis Z, 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, third lens L3, fourth lens L4, and seventh lens L7 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 quantity. c is the reciprocal of the paraxial radius of curvature, k is the conicity coefficient, and r is the ray 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, "-3.58484E-03" means "-3.58484 × 10⁻³".

[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, f1 represents the focal length of the first lens L1. f2 represents the focal length of the second lens L2, and 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, f6 represents the focal length of the sixth lens L6, and f7 represents the focal length of the seventh lens L7. f represents the focal length of the entire lens system from the first lens L1 to the sixth lens L6.

[0052] Furthermore, Ze3 indicates the sag amount of the edge (effective aperture) of the effective surface of the image-side lens surface S6 of the third lens L3. Ze4 indicates the sag amount of the edge (effective aperture) of the effective surface of the object-side lens surface S9 of the fourth lens L4. TTL indicates the total optical length along the optical axis Z from the object-side lens surface S1 of the first lens L1 to the image-forming surface S21 of the image sensor 12.

[0053] The camera module 10 at this time has a bright f-number of 1.6, and its half-angle of view is 100°, making it an ultra-wide-angle lens. The half-angle of view can also be an ultra-wide-angle lens that supports a wide field of view, such as a fisheye lens with an angle of view of 180° or more.

[0054] Figure 2(a) shows the spherical aberration of the imaging lens system 11 of Example 1. The horizontal axis of Figure 2(a) represents the distance in the direction perpendicular to the optical axis Z. The vertical axis shows the pupil diameter of 0.4683 mm in normalized pupil coordinates. In addition, the solid line in Figure 2(a) represents the wavelength of light 0.546 μm, the dotted line represents the wavelength of light 0.478 μm, and the dashed line represents 0.656 μm. Thus, the imaging lens system 11 of Example 1 has little distance deviation in the direction perpendicular to the optical axis Z, and the spherical aberration is corrected to an appropriate range.

[0055] Figure 2(b) shows the field curvature of the imaging lens system 11 of Example 1. In Figure 2(b), the horizontal axis represents the distance in the direction perpendicular to the optical axis Z, and the vertical axis represents the image height (angle of view). In Figure 2(b), the solid line represents the field curvature Sag in the sagittal plane, and the dotted line represents the field curvature Tan in the tangential plane. The wavelength of the light ray at this time is 0.5461 μm. Thus, in the imaging lens system 11 of Example 1, the distance difference between the field curvature Sag and the field curvature Tan in the direction perpendicular to the optical axis Z is small, and astigmatism is corrected to an appropriate range.

[0056] Figure 2(c) shows the distortion aberration of the imaging lens system 11 of Example 1. In Figure 2(c), the horizontal axis represents the ratio in the direction perpendicular to the optical axis Z, and the vertical axis represents the image height (angle of view). The wavelength of the light ray at this time is 0.5461 μm. As shown above, the imaging lens system 11 of Example 1 has a small ratio in the direction perpendicular to the optical axis Z, and the distortion aberration is corrected to an appropriate range.

[0057] Figure 3 shows the lateral aberration of the imaging lens system 11 of Example 1. Figure 3(a) shows the lateral aberration at 0 degrees, Figure 3(b) at 20 degrees, Figure 3(c) at 40 degrees, Figure 3(d) at 60 degrees, Figure 3(e) at 80 degrees, and Figure 3(f) at 100 degrees. The horizontal axis of Figure 3 shows the lateral aberration ey and ex, and the vertical axis shows the entrance pupil coordinates Py and Px, representing the range from -20 μm to +20 μm. The solid line in Figure 3 represents the wavelength of light 0.546 μm, the dashed line represents the wavelength of light 0.478 μm, and the dotted line represents 0.656 μm. Thus, the imaging lens system 11 of Example 1 has minimal distance shift and the lateral aberration is corrected to an appropriate range.

[0058] Figure 4 shows the eccentricity sensitivity of the imaging lens system 11 of Example 1. Figure 4(a) is Figure 3(a) showing the nominal state on the axis. Figure 4(b) shows the third lens L3 changed by -30 μm, Figure 4(c) shows the third lens L3 changed by +30 μm, Figure 4(d) shows the fourth lens L4 changed by -30 μm, and Figure 4(e) shows the fourth lens L4 changed by +30 μm. In addition, the solid line in Figure 4 represents the wavelength of light 0.546 μm, the dashed line represents the wavelength of light 0.478 μm, and the dotted line represents 0.656 μm. Thus, the imaging lens system 11 of Example 1 corrects lateral aberration to an appropriate range while maintaining good eccentricity sensitivity.

[0059] [Example 2] Figure 5 is a cross-sectional view showing the configuration of the imaging lens system 11 of the camera module 10 in Embodiment 2. Embodiment 2 in Figure 5 differs from Embodiment 1 in Figure 1 in lens data, etc. As shown in Figure 5, the imaging lens system 11 of Embodiment 2 comprises 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 in the order of the optical axis Z direction from the object side to the image side.

[0060] Furthermore, the imaging lens system 11 has a front lens group that determines the angle of view characteristics, etc., through the first lens L1, the second lens L2, and the third lens L3. 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 fourth lens L4, the fifth lens L5, the sixth lens L6, and the seventh lens L7, flanking the optical aperture 1.

[0061] The first lens L1 has a spherical lens surface S1 with positive curvature that is convex towards the object side, and a spherical lens surface S2 with negative curvature that is concave towards the image side. The first lens L1 is a negative lens with a negative refractive power (negative power) that diffuses light rays, and is a meniscus-shaped glass lens with a thicker edge than the center.

[0062] The second lens L2 has an aspherical lens surface S3 with positive curvature and a convex shape towards the object, and an aspherical lens surface S4 with negative curvature and a concave shape towards the image. The second lens L2 is a meniscus-shaped glass lens with a negative refractive power (negative power) that diffuses light rays, and is thicker at the edges than at the center.

[0063] The third lens L3 has an aspherical lens surface S5 with positive curvature and a convex shape towards the object, and an aspherical lens surface S6 with negative curvature and a concave shape towards the image. The radius of curvature of lens surface S6 is much longer than the radius of curvature of lens surface S5, and also longer than the radius of curvature of lens surface S9 of the fourth lens L4, which will be described later. Lens surface S6 corrects coma aberration with a gentle curve (almost flat curve). The third lens L3 is a positive glass lens that has a positive refractive power (positive power) that converges light rays, and is thicker towards the center than towards the edges.

[0064] The optical diaphragm 1 (STOP) has an opening that allows light rays to pass through the optical diaphragm surfaces S7 and S8, and the amount of light rays is set by the diameter of the opening. The optical diaphragm 1 is a thin, non-transparent resin.

[0065] The fourth lens L4 has an aspherical lens surface S9 with negative curvature and a concave shape on the object side, and an aspherical lens surface S10 with positive curvature and a convex shape on the image side. The concave lens surface S9 corrects coma aberration. The fourth lens L4 is a positive glass lens that has positive refractive power (positive power) that converges light rays, and is thicker on the center side than on the edges. In addition, the lens surface S6 of the third lens L3 and the lens surface S9 of the fourth lens L4 form an air lens, correcting spherical aberration and coma aberration.

[0066] The fifth lens L5 has a spherical lens surface S11 with positive curvature that is convex towards the object side, and a spherical lens surface S12 with positive curvature that is convex towards the image side. The fifth lens L5 is a positive glass lens that has positive refractive power (positive power) that converges light rays, and is thicker towards the center than towards the edge.

[0067] The sixth lens L6 has a spherical lens surface S13 with negative curvature and a concave shape on the object side, and a spherical lens surface S14 with negative curvature and a concave shape on the image side. The sixth lens L6 is a negative glass lens that has a negative refractive power (negative power) that diffuses light rays, and is thicker at the edges than at the center.

[0068] Furthermore, the image-side lens surface S12 of the fifth lens L5 is bonded to the object-side lens surface S13 of the sixth lens L6 by applying a synthetic resin adhesive, thereby forming a cemented lens with the fifth lens L5 and the sixth lens L6. This cemented lens is a lens with negative refractive power (negative energy) that diffuses light rays. By combining the fifth lens L5 and the sixth lens L6, axial chromatic aberration and lateral chromatic aberration can be corrected, and the cemented surface performs higher-order aberration correction.

[0069] The seventh lens L7 has an aspherical lens surface S15 with positive curvature that is convex towards the object side, and an aspherical lens surface S16 with positive curvature that is convex towards the image side. The seventh lens L7 is a positive glass lens that has a positive refractive power (positive power) that converges light rays, and is thicker on the center side than on the edge side of the lens.

[0070] The Fno (F-number) of the imaging lens system 11 is 1.6. These fourth lens L4 to seventh lens L7 correct 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 1.6) is achieved.

[0071] Furthermore, the camera module 10 in Figure 5 includes an IR cut filter 14, a cover glass 13, and an image sensor 12, similar to those in Figure 1.

[0072] Thus, the camera module 10 comprises an imaging lens system 11, an optical aperture 1, an IR cut filter 14, a cover glass 13, and an image sensor 12, and is fixed to the housing of the camera module 10 or the imaging lens system 11 by a flange or the like.

[0073] 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.

[0074] [Table 4]

[0075] 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.

[0076] [Table 5]

[0077] 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 shows the characteristic values ​​for Example 1. Note that the F-number of the camera module 10 in this case is a bright 1.6, and the half-angle of view is 100°, making it an ultra-wide-angle lens.

[0078] [Table 6]

[0079] Figure 6(a) shows the spherical aberration of the imaging lens system 11 of Example 2. Figure 6(a) shows graphs for the same items as in Figure 2(a). Note that Figure 6(a) shows normalized pupil coordinates with a pupil diameter of 0.4618 mm. In addition, the solid line in Figure 6(a) represents a wavelength of light of 0.546 μm, the dotted line represents a wavelength of light of 0.478 μm, and the dashed line represents 0.656 μm.

[0080] Figure 6(b) shows the field curvature of the imaging lens system 11 of Example 2. Figure 6(b) shows graphs for the same items as in Figure 2(b). The wavelength of the light ray in Figure 6(b) is 0.5461 μm.

[0081] Figure 6(c) shows the distortion aberration of the imaging lens system 11 of Example 2. Figure 6(c) shows graphs for the same items as in Figure 2(c). The wavelength of the light rays in Figure 6(c) is 0.5461 μm. In this way, the imaging lens system 11 of Example 2 has spherical aberration, astigmatism, and distortion aberration corrected to an appropriate range.

[0082] Figure 7 shows the lateral aberration of the imaging lens system 11 of Example 2. Figure 7 shows graphs for the same items as in Figure 3. In Figure 7, the solid line represents a wavelength of light of 0.546 μm, the dashed line represents a wavelength of light of 0.478 μm, and the dotted line represents 0.656 μm. Thus, the imaging lens system 11 of Example 2 has its lateral aberration corrected to an appropriate range.

[0083] Figure 8 shows the eccentricity sensitivity of the imaging lens system 11 of Example 2. Figure 8 shows graphs for the same items as in Figure 4. In Figure 8, the solid line represents a wavelength of light of 0.546 μm, the dashed line represents a wavelength of light of 0.478 μm, and the dotted line represents 0.656 μm. Thus, the imaging lens system 11 of Example 2 corrects lateral aberration to an appropriate range while maintaining good eccentricity sensitivity.

[0084] [Example 3] Figure 9 is a cross-sectional view showing the configuration of the imaging lens system 11 of the camera module 10 in Embodiment 3. Embodiment 3 in Figure 9 differs from Embodiment 1 in Figure 1 in lens data, etc. As shown in Figure 9, the imaging lens system 11 of Embodiment 3 comprises 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 in the order of the optical axis Z direction from the object side to the image side.

[0085] Furthermore, the imaging lens system 11 has a front lens group that determines the angle of view characteristics, etc., through the first lens L1, the second lens L2, and the third lens L3. 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 fourth lens L4, the fifth lens L5, the sixth lens L6, and the seventh lens L7, flanking the optical aperture 1.

[0086] The first lens L1 has a spherical lens surface S1 with positive curvature that is convex towards the object side, and a spherical lens surface S2 with negative curvature that is concave towards the image side. The first lens L1 is a negative lens with a negative refractive power (negative power) that diffuses light rays, and is a meniscus-shaped glass lens with a thicker edge than the center.

[0087] The second lens L2 has an aspherical lens surface S3 with positive curvature and a convex shape towards the object, and an aspherical lens surface S4 with negative curvature and a concave shape towards the image. The second lens L2 is a meniscus-shaped glass lens with a negative refractive power (negative power) that diffuses light rays, and is thicker at the edges than at the center.

[0088] The third lens L3 has an aspherical lens surface S5 with positive curvature that is convex towards the object side, and an aspherical lens surface S6 with positive curvature that is convex towards the image side. The radius of curvature of lens surface S6 is much longer than the radius of curvature of lens surface S5, and also longer than the radius of curvature of lens surface S9 of the fourth lens L4, which will be described later. Lens surface S6 corrects coma aberration with a gentle curve (almost flat curve). The third lens L3 is a positive glass lens that has a positive refractive power (positive power) that converges light rays, and is thicker towards the center than towards the edges.

[0089] The optical diaphragm 1 (STOP) has an opening that allows light rays to pass through the optical diaphragm surfaces S7 and S8, and the amount of light rays is set by the diameter of the opening. The optical diaphragm 1 is a thin, non-transparent resin.

[0090] The fourth lens L4 has an aspherical lens surface S9 with negative curvature and a concave shape on the object side, and an aspherical lens surface S10 with positive curvature and a convex shape on the image side. The concave lens surface S9 corrects coma aberration. The fourth lens L4 is a positive glass lens that has positive refractive power (positive power) that converges light rays, and is thicker on the center side than on the edges. In addition, the lens surface S6 of the third lens L3 and the lens surface S9 of the fourth lens L4 form an air lens, correcting spherical aberration and coma aberration.

[0091] The fifth lens L5 has a spherical lens surface S11 with positive curvature that is convex towards the object side, and a spherical lens surface S12 with positive curvature that is convex towards the image side. The fifth lens L5 is a positive glass lens that has positive refractive power (positive power) that converges light rays, and is thicker towards the center than towards the edge.

[0092] The sixth lens L6 has a spherical lens surface S13 with negative curvature and a concave shape on the object side, and a spherical lens surface S14 with negative curvature and a concave shape on the image side. The sixth lens L6 is a negative glass lens that has a negative refractive power (negative power) that diffuses light rays, and is thicker at the edges than at the center.

[0093] Furthermore, the image-side lens surface S12 of the fifth lens L5 is bonded to the object-side lens surface S13 of the sixth lens L6 by applying a synthetic resin adhesive, thereby forming a cemented lens with the fifth lens L5 and the sixth lens L6. This cemented lens is a lens with negative refractive power (negative energy) that diffuses light rays. By combining the fifth lens L5 and the sixth lens L6, axial chromatic aberration and lateral chromatic aberration can be corrected, and the cemented surface performs higher-order aberration correction.

[0094] The seventh lens L7 has an aspherical lens surface S15 with positive curvature that is convex towards the object side, and an aspherical lens surface S16 with positive curvature that is convex towards the image side. The seventh lens L7 is a positive glass lens that has a positive refractive power (positive power) that converges light rays, and is thicker on the center side than on the edge side of the lens.

[0095] The Fno (F-number) of the imaging lens system 11 is 1.6. These fourth lens L4 to seventh lens L7 correct 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 1.6) is achieved.

[0096] Furthermore, the camera module 10 in Figure 9 includes an IR cut filter 14, a cover glass 13, and an image sensor 12, similar to those in Figure 1.

[0097] Thus, the camera module 10 comprises an imaging lens system 11, an optical aperture 1, an IR cut filter 14, a cover glass 13, and an image sensor 12, and is fixed to the housing of the camera module 10 or the imaging lens system 11 by a flange or the like.

[0098] 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.

[0099] [Table 7]

[0100] 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.

[0101] [Table 8]

[0102] 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 those shown in Table 3, which shows the characteristic values ​​for Example 1. Note that the F-number of the camera module 10 in this case is a bright 1.6, and the half-angle of view is 100°, making it an ultra-wide-angle lens.

[0103] [Table 9]

[0104] Figure 10(a) shows the spherical aberration of the imaging lens system 11 of Example 3. Figure 10(a) shows graphs for the same items as in Figure 2(a). Note that Figure 10(a) shows the pupil diameter of 0.4797 mm as the normalized pupil coordinate. In addition, the solid line in Figure 10(a) represents the wavelength of light of 0.558 μm, the dotted line represents the wavelength of light of 0.478 μm, and the dashed line represents 0.656 μm.

[0105] Figure 10(b) shows the field curvature of the imaging lens system 11 of Example 3. Figure 19(b) shows graphs for the same items as in Figure 2(b). The wavelength of the light ray in Figure 10(b) is 0.5580 μm.

[0106] Figure 10(c) shows the distortion aberration of the imaging lens system 11 of Example 3. Figure 10(c) shows graphs for the same items as in Figure 2(c). The wavelength of the light rays in Figure 10(c) is 0.5580 μm. In this way, the imaging lens system 11 of Example 3 corrects spherical aberration, astigmatism, and distortion aberration to an appropriate range.

[0107] Figure 11 shows the lateral aberration of the imaging lens system 11 of Example 3. Figure 11 shows graphs for the same items as in Figure 3. In Figure 11, the solid line represents a wavelength of light of 0.558 μm, the dashed line represents a wavelength of light of 0.478 μm, and the dotted line represents 0.656 μm. Thus, the imaging lens system 11 of Example 3 has its lateral aberration corrected to an appropriate range.

[0108] Figure 12 shows the eccentricity sensitivity of the imaging lens system 11 of Example 3. Figure 12 shows graphs for the same items as in Figure 4. In Figure 12, the solid line represents a wavelength of light of 0.558 μm, the dashed line represents a wavelength of light of 0.478 μm, and the dotted line represents 0.656 μm. Thus, the imaging lens system 11 of Example 3 corrects lateral aberration to an appropriate range while maintaining good eccentricity sensitivity.

[0109] [Example 4] Figure 13 is a cross-sectional view showing the configuration of the imaging lens system 11 of the camera module 10 in Embodiment 4. Embodiment 4 in Figure 13 differs from Embodiment 1 in Figure 1 in lens data, etc. As shown in Figure 13, the imaging lens system 11 of Embodiment 4 comprises 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 in the order of the optical axis Z direction from the object side to the image side.

[0110] Furthermore, the imaging lens system 11 has a front lens group that determines the angle of view characteristics, etc., through the first lens L1, the second lens L2, and the third lens L3. 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 fourth lens L4, the fifth lens L5, the sixth lens L6, and the seventh lens L7, flanking the optical aperture 1.

[0111] The first lens L1 has a spherical lens surface S1 with positive curvature that is convex towards the object side, and a spherical lens surface S2 with negative curvature that is concave towards the image side. The first lens L1 is a negative lens with a negative refractive power (negative power) that diffuses light rays, and is a meniscus-shaped glass lens with a thicker edge than the center.

[0112] The second lens L2 has an aspherical lens surface S3 with positive curvature and a convex shape towards the object, and an aspherical lens surface S4 with negative curvature and a concave shape towards the image. The second lens L2 is a meniscus-shaped glass lens with a negative refractive power (negative power) that diffuses light rays, and is thicker at the edges than at the center.

[0113] The third lens L3 has an aspherical lens surface S5 with positive curvature that is convex towards the object side, and an aspherical lens surface S6 with positive curvature that is convex towards the image side. The radius of curvature of lens surface S6 is much longer than the radius of curvature of lens surface S5, and also longer than the radius of curvature of lens surface S9 of the fourth lens L4, which will be described later. Lens surface S6 corrects coma aberration with a gentle curve (almost flat curve). The third lens L3 is a positive glass lens that has a positive refractive power (positive power) that converges light rays, and is thicker towards the center than towards the edges.

[0114] The optical diaphragm 1 (STOP) has an opening that allows light rays to pass through the optical diaphragm surfaces S7 and S8, and the amount of light rays is set by the diameter of the opening. The optical diaphragm 1 is a thin, non-transparent resin.

[0115] The fourth lens L4 has an aspherical lens surface S9 with negative curvature and a concave shape on the object side, and an aspherical lens surface S10 with positive curvature and a convex shape on the image side. The concave lens surface S9 corrects coma aberration. The fourth lens L4 is a positive glass lens that has positive refractive power (positive power) that converges light rays, and is thicker on the center side than on the edges. In addition, the lens surface S6 of the third lens L3 and the lens surface S9 of the fourth lens L4 form an air lens, correcting spherical aberration and coma aberration.

[0116] The fifth lens L5 has a spherical lens surface S11 with positive curvature that is convex towards the object side, and a spherical lens surface S12 with positive curvature that is convex towards the image side. The fifth lens L5 is a positive glass lens that has positive refractive power (positive power) that converges light rays, and is thicker towards the center than towards the edge.

[0117] The sixth lens L6 has a spherical lens surface S13 with negative curvature and a concave shape on the object side, and a spherical lens surface S14 with negative curvature and a concave shape on the image side. The sixth lens L6 is a negative glass lens that has a negative refractive power (negative power) that diffuses light rays, and is thicker at the edges than at the center.

[0118] Furthermore, the image-side lens surface S12 of the fifth lens L5 is bonded to the object-side lens surface S13 of the sixth lens L6 by applying a synthetic resin adhesive, thereby forming a cemented lens with the fifth lens L5 and the sixth lens L6. This cemented lens is a lens with negative refractive power (negative energy) that diffuses light rays. By combining the fifth lens L5 and the sixth lens L6, axial chromatic aberration and lateral chromatic aberration can be corrected, and the cemented surface performs higher-order aberration correction.

[0119] The seventh lens L7 has an aspherical lens surface S15 with positive curvature that is convex towards the object side, and an aspherical lens surface S16 with positive curvature that is convex towards the image side. The seventh lens L7 is a positive glass lens that has a positive refractive power (positive power) that converges light rays, and is thicker on the center side than on the edge side of the lens.

[0120] The Fno (F-number) of the imaging lens system 11 is 1.6. These fourth lens L4 to seventh lens L7 correct 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 1.6) is achieved.

[0121] Furthermore, the camera module 10 in Figure 13 includes an IR cut filter 14, a cover glass 13, and an image sensor 12, similar to those in Figure 1.

[0122] Thus, the camera module 10 comprises an imaging lens system 11, an optical aperture 1, an IR cut filter 14, a cover glass 13, and an image sensor 12, and is fixed to the housing of the camera module 10 or the imaging lens system 11 by a flange or the like.

[0123] Table 10 shows the lens data for each lens surface of the imaging lens system 11 in Example 4. The lens data in Table 10 shows data for the same items as in Table 1.

[0124] [Table 10]

[0125] 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.

[0126] [Table 11]

[0127] Table 12 shows the characteristic values ​​for the imaging lens system 11 of Example 4, as shown in Tables 10 and 11, etc., for the same items as shown in Table 3, which shows the characteristic values ​​for Example 1. Note that the F-number of the camera module 10 in this case is a bright 1.6, and the half-angle of view is 100°, making it an ultra-wide-angle lens.

[0128] [Table 12]

[0129] Figure 14(a) shows the spherical aberration of the imaging lens system 11 of Example 4. Figure 14(a) shows graphs for the same items as in Figure 2(a). Note that Figure 14(a) shows normalized pupil coordinates with a pupil diameter of 0.4797 mm. In addition, the solid line in Figure 14(a) represents a wavelength of light of 0.558 μm, the dotted line represents a wavelength of light of 0.478 μm, and the dashed line represents 0.656 μm.

[0130] Figure 14(b) shows the field curvature of the imaging lens system 11 of Example 4. Figure 14(b) shows graphs for the same items as in Figure 2(b). The wavelength of the light rays in Figure 14(b) is 0.5461 μm.

[0131] Figure 14(c) shows the distortion aberration of the imaging lens system 11 of Example 4. Figure 14(c) shows graphs for the same items as in Figure 2(c). The wavelength of the light rays in Figure 14(c) is 0.5461 μm. In this way, the imaging lens system 11 of Example 4 corrects spherical aberration, astigmatism, and distortion aberration to an appropriate range.

[0132] Figure 15 shows the lateral aberration of the imaging lens system 11 of Example 4. Figure 15 shows graphs for the same items as in Figure 3. In Figure 15, the solid line represents a wavelength of light of 0.546 μm, the dashed line represents a wavelength of light of 0.478 μm, and the dotted line represents 0.656 μm. Thus, the imaging lens system 11 of Example 4 has its lateral aberration corrected to an appropriate range.

[0133] Figure 16 shows the eccentricity sensitivity of the imaging lens system 11 of Example 4. Figure 16 shows graphs for the same items as in Figure 4. In Figure 16, the solid line represents a wavelength of light of 0.546 μm, the dashed line represents a wavelength of light of 0.478 μm, and the dotted line represents 0.656 μm. Thus, the imaging lens system 11 of Example 4 corrects lateral aberration to an appropriate range while maintaining good eccentricity sensitivity.

[0134] [Example 5] Figure 17 is a cross-sectional view showing the configuration of the imaging lens system 11 of the camera module 10 in Embodiment 5. Embodiment 5 in Figure 17 differs from Embodiment 1 in Figure 1 in lens data, etc. As shown in Figure 17, the imaging lens system 11 of Embodiment 5 comprises 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 in the order of the optical axis Z direction from the object side to the image side.

[0135] Furthermore, the imaging lens system 11 has a front lens group that determines the angle of view characteristics, etc., through the first lens L1, the second lens L2, and the third lens L3. 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 fourth lens L4, the fifth lens L5, the sixth lens L6, and the seventh lens L7, flanking the optical aperture 1.

[0136] The first lens L1 has a spherical lens surface S1 with positive curvature that is convex towards the object side, and a spherical lens surface S2 with negative curvature that is concave towards the image side. The first lens L1 is a negative lens with a negative refractive power (negative power) that diffuses light rays, and is a meniscus-shaped glass lens with a thicker edge than the center.

[0137] The second lens L2 has an aspherical lens surface S3 with positive curvature and a convex shape towards the object, and an aspherical lens surface S4 with negative curvature and a concave shape towards the image. The second lens L2 is a meniscus-shaped glass lens with a negative refractive power (negative power) that diffuses light rays, and is thicker at the edges than at the center.

[0138] The third lens L3 has an aspherical lens surface S5 with positive curvature and a convex shape towards the object, and an aspherical lens surface S6 with negative curvature and a concave shape towards the image. The radius of curvature of lens surface S6 is much longer than the radius of curvature of lens surface S5, and also longer than the radius of curvature of lens surface S9 of the fourth lens L4, which will be described later. Lens surface S6 corrects coma aberration with a gentle curve (almost flat curve). The third lens L3 is a positive glass lens that has a positive refractive power (positive power) that converges light rays, and is thicker towards the center than towards the edges.

[0139] The optical diaphragm 1 (STOP) has an opening that allows light rays to pass through the optical diaphragm surfaces S7 and S8, and the amount of light rays is set by the diameter of the opening. The optical diaphragm 1 is a thin, non-transparent resin.

[0140] The fourth lens L4 has an aspherical lens surface S9 with negative curvature and a concave shape on the object side, and an aspherical lens surface S10 with positive curvature and a convex shape on the image side. The concave lens surface S9 corrects coma aberration. The fourth lens L4 is a positive glass lens that has positive refractive power (positive power) that converges light rays, and is thicker on the center side than on the edges. In addition, the lens surface S6 of the third lens L3 and the lens surface S9 of the fourth lens L4 form an air lens, correcting spherical aberration and coma aberration.

[0141] The fifth lens L5 has a spherical lens surface S11 with positive curvature that is convex towards the object side, and a spherical lens surface S12 with positive curvature that is convex towards the image side. The fifth lens L5 is a positive glass lens that has positive refractive power (positive power) that converges light rays, and is thicker towards the center than towards the edge.

[0142] The sixth lens L6 has a spherical lens surface S13 with negative curvature and a concave shape on the object side, and a spherical lens surface S14 with negative curvature and a concave shape on the image side. The sixth lens L6 is a negative glass lens that has a negative refractive power (negative power) that diffuses light rays, and is thicker at the edges than at the center.

[0143] Furthermore, the image-side lens surface S12 of the fifth lens L5 is bonded to the object-side lens surface S13 of the sixth lens L6 by applying a synthetic resin adhesive, thereby forming a cemented lens with the fifth lens L5 and the sixth lens L6. This cemented lens is a lens with negative refractive power (negative energy) that diffuses light rays. By combining the fifth lens L5 and the sixth lens L6, axial chromatic aberration and lateral chromatic aberration can be corrected, and the cemented surface performs higher-order aberration correction.

[0144] The seventh lens L7 has an aspherical lens surface S15 with positive curvature that is convex towards the object side, and an aspherical lens surface S16 with positive curvature that is convex towards the image side. The seventh lens L7 is a positive glass lens that has a positive refractive power (positive power) that converges light rays, and is thicker on the center side than on the edge side of the lens.

[0145] The Fno (F-number) of the imaging lens system 11 is 1.6. These fourth lens L4 to seventh lens L7 correct 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 1.6) is achieved.

[0146] Furthermore, the camera module 10 in Figure 17 includes an IR cut filter 14, a cover glass 13, and an image sensor 12, similar to Figure 1.

[0147] Thus, the camera module 10 comprises an imaging lens system 11, an optical aperture 1, an IR cut filter 14, a cover glass 13, and an image sensor 12, and is fixed to the housing of the camera module 10 or the imaging lens system 11 by a flange or the like.

[0148] 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 1.

[0149] [Table 13]

[0150] 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 same values ​​for the same items as in Table 2.

[0151] [Table 14]

[0152] 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 3, which shows the characteristic values ​​for Example 1. Note that the F-number of the camera module 10 in this case is a bright 1.6, and the half-angle of view is 100°, making it an ultra-wide-angle lens.

[0153] [Table 15]

[0154] Figure 18(a) shows the spherical aberration of the imaging lens system 11 of Example 5. Figure 18(a) shows graphs for the same items as in Figure 2(a). Note that Figure 18(a) shows normalized pupil coordinates with a pupil diameter of 0.4860 mm. In addition, the solid line in Figure 18(a) represents a wavelength of light of 0.546 mm, the dotted line represents a wavelength of light of 0.478 μm, and the dashed line represents 0.656 μm.

[0155] Figure 18(b) shows the field curvature of the imaging lens system 11 of Example 5. Figure 18(b) shows graphs for the same items as in Figure 2(b). The wavelength of the light rays in Figure 18(b) is 0.5461 μm.

[0156] Figure 18(c) shows the distortion aberration of the imaging lens system 11 of Example 5. Figure 18(c) shows graphs for the same items as in Figure 2(c). The wavelength of the light rays in Figure 18(c) is 0.5461 μm. In this way, the imaging lens system 11 of Example 5 has its spherical aberration, astigmatism, and distortion aberration corrected to an appropriate range.

[0157] Figure 19 shows the lateral aberration of the imaging lens system 11 of Example 5. Figure 19 shows graphs for the same items as in Figure 3. In Figure 19, the solid line represents a wavelength of light of 0.546 μm, the dashed line represents a wavelength of light of 0.478 μm, and the dotted line represents 0.656 μm. Thus, the imaging lens system 11 of Example 5 has its lateral aberration corrected to an appropriate range.

[0158] Figure 20 shows the eccentricity sensitivity of the imaging lens system 11 of Example 5. Figure 20 shows graphs for the same items as in Figure 4. In Figure 20, the solid line represents a wavelength of light of 0.546 μm, the dashed line represents a wavelength of light of 0.478 μm, and the dotted line represents 0.656 μm. Thus, the imaging lens system 11 of Example 5 corrects lateral aberration to an appropriate range while maintaining good eccentricity sensitivity.

[0159] [Summary of conditional expressions] Table 16 summarizes the characteristic values ​​of the imaging lens system 11 for Examples 1 to 5. Table 17 shows related values ​​calculated from the values ​​in Table 16 and other tables.

[0160] [Table 16]

[0161] [Table 17]

[0162] The imaging lens system 11 satisfies the following condition (1) when the radius of curvature of the image-side lens surface S6 of the third lens L3 is defined as L3R2 and the radius of curvature of the object-side lens surface S9 of the fourth lens L4 is defined as L4R1.

[0163] -1.5<-(L3R2+L4R1) / (L3R2-L4R1)<-0.8 ···(1) Furthermore, it is preferable that the imaging lens system 11 satisfies -1.22 ≤ -(L3R2 + L4R1) / (L3R2 - L4R1) ≤ -0.88.

[0164] By satisfying this condition (1), the imaging lens system 11 creates an air lens between the image-side lens surface S6 of the third lens L3 and the object-side lens surface S9 of the fourth lens L4. By satisfying this condition (1), the camera module 10 can effectively correct spherical aberration and coma aberration, satisfy resolution performance requirements, and obtain bright, high-resolution capabilities that correspond to a wide field of view.

[0165] If -(L3R2+L4R1) / (L3R2-L4R1) in condition (1) is less than -1.5 or -1.22, the refractive power of the fourth lens L4 in the imaging lens system 11 increases. That is, in the imaging lens system 11, the concave shape of the object-side lens surface S9 of the fourth lens L4 has insufficient power, and the convex shape of the image-side lens surface S10 has relatively excessive power, resulting in an increased refractive power of the fourth lens L4. As a result, the camera module 10 experiences increased coma aberration in the fourth lens L4, especially when the fourth lens L4 is eccentric.

[0166] On the other hand, if -(L3R2+L4R1) / (L3R2-L4R1) in condition (1) is greater than -0.8 or -0.88, the imaging lens system 11 will have excessive power in the concave shape of the object-side lens surface S9 of the fourth lens L4. In other words, the imaging lens system 11 will have a large refractive power at the lens surface S9 of the fourth lens L4. As a result, it will be difficult for the camera module 10 to correct spherical aberration and coma aberration. It should be noted that condition (1) is more preferable when the radius of curvature L3R2 of the image-side lens surface S6 of the third lens L3 is positive.

[0167] Furthermore, the imaging lens system 11 should satisfy the following condition (2) when the focal length of the third lens L3 is f3 and the focal length of the fourth lens L4 is f4.

[0168] 0.8 <f3 / f4<1.25 ···(2) Furthermore, it is preferable that the imaging lens system 11 satisfies 0.844 ≤ -(L3R2 + L4R1) / (L3R2 - L4R1) ≤ 0.897.

[0169] By satisfying this condition (2), the imaging lens system 11 can set the power distribution between the third lens L3 and the fourth lens L4 within a predetermined range, and the camera module 10 can effectively correct coma aberration.

[0170] If the f3 / f4 in condition (2) is less than 0.8 or 0.844, the positive power of the light rays converging in the third lens L3 becomes relatively larger in the imaging lens system 11, and the refractive power of the third lens L3 increases. As a result, the camera module 10 experiences increased coma aberration in the third lens L3, especially when the third lens L3 is deviated.

[0171] On the other hand, if the f3 / f4 in condition (2) is greater than 1.25 or 0.897, the positive power of the light rays converging in the fourth lens L4 becomes relatively larger in the imaging lens system 11, and the refractive power of the fourth lens L4 increases. As a result, the camera module 10 experiences increased coma aberration in the fourth lens L4, especially coma aberration when the fourth lens L4 is deviated.

[0172] Furthermore, the imaging lens system 11 should satisfy the following condition (3) when Ze3 is the sag amount of the edge of the effective surface of the image-side lens surface S6 of the third lens L3, and TTL is the total optical length along the optical axis Z from the object-side lens surface S1 of the first lens L1 to the image-forming surface S21 of the image sensor 12.

[0173] 0.0001 <Ze3 / TTL<0.010 ···(3) Furthermore, it is preferable that the imaging lens system 11 satisfies the condition 0.0021 ≤ Ze3 / TTL ≤ 0.0047.

[0174] By satisfying condition (3), the imaging lens system 11 can set the power of the image-side lens surface S6 of the third lens L3 to an appropriate range, and the camera module 10 can effectively correct spherical aberration and coma aberration.

[0175] If Ze3 / TTL in condition (3) is less than 0.0001 or 0.0021, the refractive power of the object-side lens surface S9 of the fourth lens L4 in the imaging lens system 11 increases. In other words, the power of the image-side lens surface S6 of the third lens L3 decreases in the imaging lens system 11, and the power of the object-side lens surface S9 of the fourth lens L4 that compensates for this inevitably increases, resulting in a higher refractive power of the object-side lens surface S9 of the fourth lens L4. As a result, it becomes difficult for the camera module 10 to correct spherical aberration and coma aberration.

[0176] On the other hand, if Ze3 / TTL in condition (3) is greater than 0.010 or 0.0047, the refractive power of the fourth lens L4 in the imaging lens system 11 increases. That is, in the imaging lens system 11, the power of the image-side lens surface S6 of the third lens L3 increases, and the power of the object-side lens surface S9 of the compensating fourth lens L4 inevitably decreases. As a result, the imaging lens system 11 has insufficient power on the object-side lens surface S9 of the fourth lens L4, and the positive power that converges the overall light rays of the fourth lens L4 becomes excessive, increasing the refractive power of the fourth lens L4. Consequently, the camera module 10 experiences increased coma aberration, especially coma aberration when the fourth lens L4 is eccentric.

[0177] Furthermore, the imaging lens system 11 should satisfy the following condition (4) when Ze4 is the sag amount of the edge of the effective surface of the object-side lens surface S9 of the fourth lens L4, and TTL is the total optical distance along the optical axis Z from the object-side lens surface S1 of the first lens L1 to the image-forming surface S21 of the image sensor 12.

[0178] -0.02 <Ze4 / TTL<-0.01 ···(4) Furthermore, it is preferable that the imaging lens system 11 satisfies -0.0163 ≤ Ze4 / TTL ≤ -0.0150.

[0179] By satisfying this condition (4), the imaging lens system 11 can set the power of the object-side lens surface S9 of the fourth lens L4 to an appropriate range, and the camera module 10 can effectively correct spherical aberration and coma aberration.

[0180] If Ze4 / TTL in condition (4) is less than -0.02 or -0.0163, the refractive power of the object-side lens surface S9 of the fourth lens L4 in the imaging lens system 11 increases, making it difficult for the camera module 10 to correct spherical aberration and coma aberration.

[0181] On the other hand, if Ze4 / TTL in condition (4) is greater than -0.01 or -0.0150, the refractive power of the fourth lens L4 in the imaging lens system 11 increases. That is, in the imaging lens system 11, the power of the object-side lens surface S9 of the fourth lens L4 is insufficient, and the positive power that converges the overall light rays of the fourth lens L4 becomes excessive, resulting in an increased refractive power of the fourth lens L4. As a result, the camera module 10 experiences increased coma aberration in the fourth lens L4, especially coma aberration during eccentricity.

[0182] [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.

[0183] 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 21 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.

[0184] 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.

[0185] 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.

[0186] 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.

[0187] 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.

[0188] 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.

[0189] 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 22 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 thereon into an electrical signal.

[0190] As shown in Figure 22, the vehicle 40, which is an automobile that travels day and night, is equipped with tires, steering, etc., for driving. The vehicle 40, being a mobile unit, 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.

[0191] Figure 22 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 to monitor 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 to monitor 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.

[0192] 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.

[0193] Figure 23 is a diagram showing the configuration of a vehicle 40 equipped with an on-board system 41, 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 the system into an electrical signal.

[0194] As shown in Figure 23, 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.

[0195] As shown in Figure 23, 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.

[0196] 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 22, by combining them. The information processing device 42 may be composed of, for example, a processor unit (PU), RAM, ROM, etc.

[0197] 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.

[0198] 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.

[0199] 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 system, a collision mitigation braking system, a distance control device, and a lane departure warning system.

[0200] 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.

[0201] 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.

[0202] 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 for other applications such as fixed surveillance cameras and cameras mounted on small electronic devices such as portable mobile phones.

[0203] 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.

[0204] 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]

[0205] 1: Optical aperture (STOP), 10: Camera module, 11: Imaging lens system, 12: Image sensor (IMG), 13: Cover glass (CG), 14: IR cut filter (IRCF), 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~S6, S9~S16: Lens surface, S7, S8: Optical aperture surface, S17, S18: IRCF surface, S19, S20: CG surface, S21: Image plane.

Claims

1. In an imaging lens system, the components are arranged in order from the object side to the image side: a front lens group, an optical aperture, and a rear lens group. The front lens group consists of a first lens with negative power in a meniscus shape, a second lens with negative power, and a third lens with positive power. The rear lens group consists of a fourth lens with positive power and a concave lens surface on the object side, a fifth lens with positive power, a sixth lens with negative power, and a seventh lens with positive power. An imaging lens system that satisfies the following condition (1), where L3R2 is the radius of curvature of the image-side lens surface of the third lens and L4R1 is the radius of curvature of the object-side lens surface of the fourth lens. -1.5<-(L3R2+L4R1) / (L3R2-L4R1)<-0.8...(1)

2. In the imaging lens system described in claim 1, An imaging lens system that satisfies the following condition (2) when the focal length of the third lens is f3 and the focal length of the fourth lens is f4. 0.8<f3 / f4<1.25...(2)

3. In the imaging lens system described in claim 1, An imaging lens system that satisfies the following condition (3), where Ze3 is the sag amount at the edge of the effective surface of the image-side lens surface of the third lens, and TTL is the distance along the optical axis from the object-side lens surface of the first lens to the image-forming surface of the image sensor. 0.0001<Ze3 / TTL<0.010...(3)

4. In the imaging lens system described in claim 1, An imaging lens system that satisfies the following condition (4), where Ze4 is the sag amount of the edge of the effective surface of the object-side lens surface of the fourth lens, and TTL is the distance along the optical axis from the object-side lens surface of the first lens to the image-forming surface of the image sensor. -0.02<Ze4 / TTL<-0.01...(4)

5. In the imaging lens system described in claim 1, The third lens is an aspherical lens; this is an imaging lens system.

6. In the imaging lens system described in claim 1, The fourth lens is an aspherical lens; this is an imaging lens system.

7. In the imaging lens system described in claim 1, The fifth lens is a cemented lens that is joined with the sixth lens, forming an imaging lens system.

8. A camera module comprising: an imaging lens system according to any one of claims 1 to 7; and an image sensor that converts light focused through the imaging lens system into an electrical signal.

9. An imaging device comprising: a camera module according to claim 8; a control unit for controlling the camera module; and a storage unit for storing information for the control unit to perform control.

10. An in-vehicle system comprising a camera module according to claim 8, and an information processing device that recognizes an object in an image captured by the camera module and generates recognition information.

11. A mobile body comprising: a camera module as described in claim 8; 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