Imaging lens system, camera module, vehicle-mounted system, and moving body

Abstract

To provide an imaging lens system, a camera module, an on-vehicle system, and a moving body which are made compact while having a wide angle and have high resolution.SOLUTION: The imaging lens system 11 includes, in order from the object side to the image side, a first lens L1 having negative power and having an object-side surface that is a convex surface facing the object side, a second lens L2 having negative power and having an image-side surface that is a concave surface facing the image side, a third lens L3 having positive power, a diaphragm STOP, a fourth lens L4 having positive power and having an image-side surface that is a convex surface facing the image side, a fifth lens L5 having negative power, and a sixth lens L6 having an image-side surface that is a convex surface facing the image side and having an inflection point. A seventh lens L7 having a positive power with an object-side surface being a convex surface facing the object side, wherein when a focal distance of a combined focal distance of the first lens L1 and the second lens L2 is defined as f12, and a focal distance of the entire optical system is defined as f, the following conditional formula (1) is satisfied: f12 / f <1.5 (1) SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an imaging lens system, a camera module, an in-vehicle system, and a moving body. [Background technology]

[0002] In recent years, in-vehicle cameras have been required to have sensing functions for detecting people and objects, and as a result, the resolution of image sensors has increased and they are becoming larger. Accordingly, the imaging lens systems mounted on in-vehicle cameras and the like are also becoming larger. Meanwhile, due to the demand for omnidirectional sensing around the vehicle, in-vehicle cameras are increasingly being mounted in spatially limited locations, such as side mirrors. Therefore, there is a growing demand for miniaturized in-vehicle cameras. Patent Document 1 describes a lens system consisting of seven lenses that is mounted on an in-vehicle camera or the like. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-102291 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the imaging lens system described in Patent Document 1, the diameter of the first lens is large, and the vehicle-mounted camera is not sufficiently compact. On the other hand, if the diameter of the first lens is reduced, it becomes difficult to obtain a sufficient angle of view.

[0005] The present invention has been made in view of the above problems, and has as its object to provide an imaging lens system, camera module, in-vehicle system, and mobile object that has a wide angle, is compact, and has high resolution. [Means for solving the problem]

[0006] An imaging lens system of one embodiment comprises, in order from the object side to the image side, a first lens having a convex object-side surface facing the object side and negative power, a second lens having a concave image-side surface facing the image side and negative power, a third lens having positive power, a stop, a fourth lens having a convex image-side surface facing the image side and positive power, a fifth lens having negative power, a sixth lens having a convex image-side surface facing the image side and having an inflection point, and a seventh lens having a convex object-side surface facing the object side and positive power, When the combined focal length of the first lens and the second lens is defined as f12 and the focal length of the entire optical system is defined as f, the following conditional expression (1) is satisfied. |f12 / f|<1.5 (1) [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a wide-angle, compact, and high-resolution imaging lens system, a camera module, an in-vehicle system, and a mobile object. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a cross-sectional view showing the configuration of a camera module and an imaging lens system according to a first embodiment. [Figure 2] 3A to 3C are diagrams showing spherical aberration (longitudinal aberration), curvature of field, and distortion in the imaging lens system of Example 1. [Figure 3] FIG. 10 is a cross-sectional view showing the configuration of a camera module and an imaging lens system according to a second embodiment. [Figure 4] 10A to 10C are diagrams showing spherical aberration (longitudinal aberration), curvature of field, and distortion in the imaging lens system of Example 2. [Figure 5] FIG. 10 is a cross-sectional view showing the configuration of a camera module and an imaging lens system according to a third embodiment. [Figure 6] 10A to 10C are diagrams showing spherical aberration (longitudinal aberration), curvature of field, and distortion in the imaging lens system of Example 3. [Figure 7] 1 is a schematic diagram of a vehicle equipped with an in-vehicle system including a camera module according to an embodiment of the present invention. [Figure 8] 8 is a block diagram showing the configuration of an imaging device that constitutes the in-vehicle system of FIG. 7. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] An embodiment of the present invention will be described below with reference to the drawings. This embodiment can realize a highly reliable system, particularly in a sensing system, ensuring healthy lives and promoting well-being for all people of all ages, and targets "3.6, by 2020, halve the number of global road traffic deaths and injuries." This embodiment also contributes to the realization of inclusive, safe, resilient, and sustainable cities and human settlements, and targets "11.2, by 2030, provide access to safe, affordable, accessible, and sustainable transport systems for all, improving road safety, including by expanding public transport, with special attention to the needs of vulnerable groups, women, children, persons with disabilities, and older persons." (Embodiment 1: Imaging lens system) The imaging lens system according to the first embodiment comprises, in order from the object side to the image side, a first lens having a convex object-side surface facing the object side and negative power, a second lens having a concave image-side surface facing the image side and negative power, a third lens having positive power, a stop, a fourth lens having a convex image-side surface facing the image side and positive power, a fifth lens having negative power, a sixth lens having a convex image-side surface facing the image side and having an inflection point, and a seventh lens having a convex object-side surface facing the object side. When the combined focal length of the first lens and the second lens is defined as f12 and the focal length of the entire optical system is defined as f, the following conditional expression (1) is satisfied. |f12 / f|<1.5 (1)

[0010] This makes it possible to provide a wide-angle, compact, and high-resolution imaging lens system. Specifically, when the imaging lens system satisfies the above conditional expression (1), the diameter of the first lens can be reduced while maintaining the angle of view of the imaging lens system, and a compact imaging lens system with a wide angle can be realized. More specifically, when the value of |f12 / f| is 1.5 or greater, the power of the first lens and the second lens is too small, making it impossible to reduce the diameter of the first lens while maintaining the angle of view of the imaging lens system. The upper limit of |f12 / f| is more preferably 1.40, 1.30, 1.20, 1.15, or 1.10, and even more preferably 1.05, 1.04, 1.03, or 1.01. Furthermore, by having the third and fourth lenses with positive power, it is possible to correct the chromatic aberration of magnification that occurs in the first and second lenses, thereby achieving high resolution in the imaging lens system. Furthermore, by making the image-side surface of the sixth lens convex toward the image side and having an inflection point, the peripheral portion of the image-side surface of the sixth lens can be made concave toward the image side. This allows light rays emitted from the peripheral portion of the sixth lens to be significantly bent off-axis, allowing the position of light rays incident on the seventh lens to be closer to the object side, thereby shortening the overall optical length of the imaging lens system. Note that the overall optical length is the distance on the optical axis from the object-side surface of the first lens L1 to the image plane in the imaging lens system. Therefore, it is possible to provide a wide-angle, compact, and high-resolution imaging lens system.

[0011] Furthermore, when the focal length of the fourth lens is defined as f4, it is preferable that the following conditional expression (2) be satisfied. 2.8 <f4 / f<3.0···(2) When the imaging lens system satisfies the above conditional expression (2), the power of the fourth lens can be increased and the curvature of the image-side surface of the fourth lens can be made sharper, thereby allowing light rays to be bent significantly by the fourth lens. This shortens the optical path required for light rays to reach a desired height from the optical axis on the object-side surface of the lens located closer to the image than the fourth lens and on the sensor surface (image-forming surface). In other words, the overall optical length of the imaging lens system can be shortened, contributing to a more compact imaging lens system. Specifically, if the value of f4 / f is 2.8 or less, the power of the fourth lens is too strong, making it difficult to correct curvature of field. On the other hand, if the value of f4 / f is 3.0 or more, the power of the fourth lens is too weak, making it difficult to sufficiently contribute to shortening the overall optical length of the imaging lens system and also making it difficult to correct spherical aberration and coma. The lower limit of f4 / f is more preferably 2.85. The upper limit of f4 / f is more preferably 2.98.

[0012] Furthermore, when the refractive index of the first lens with respect to the d-line is defined as nd1, it is preferable that the following conditional expression (3) be satisfied. nd1>1.8 (3) When the imaging lens system satisfies the above conditional expression (3), the diameter of the first lens can be reduced, and the imaging lens system can be made more compact. Specifically, if the value of nd1 is 1.8 or less, the power of the first lens is too small, making it impossible to reduce the diameter of the first lens while maintaining the angle of view of the imaging lens system. The lower limit of nd1 is more preferably 1.85, and even more preferably 1.90.

[0013] It is also preferable that the image side surface of the seventh lens be concave toward the image side. By making the image side surface of the seventh lens concave toward the image side, it is possible to effectively correct field curvature and distortion in the seventh lens, and to realize a high-resolution imaging lens system.

[0014] It is also preferable that the object side and image side surfaces of the seventh lens have aspherical shapes, and that at least one of the object side and image side surfaces of the seventh lens has at least one inflection point. The object side and image side surfaces of the seventh lens have aspherical shapes, and at least one of the object side and image side surfaces of the seventh lens has at least one inflection point, thereby making it possible to suitably correct field curvature and distortion in the seventh lens and realize a high-resolution imaging lens system.

[0015] Furthermore, when the total optical length of the imaging lens system is defined as TTL and the distance on the optical axis from the vertex of the object-side surface of the first lens to the diaphragm is defined as L1-STOP, it is preferable that the following conditional expression (4) be satisfied: (L1-STOP) / TTL<0.45 (4) When the imaging lens system satisfies the above conditional expression (4), the overall optical length of the imaging lens system can be shortened, and a more compact imaging lens system can be realized. Specifically, when the value of (L1-STOP) / TTL is 0.45 or greater, the distance on the optical axis of the lens group (front group) on the object side of the aperture stop becomes too long, which results in the distance on the optical axis of the lens group (rear group) on the image side of the aperture stop also becoming too long. The upper limit of (L1-STOP) / TTL is more preferably 0.44, 0.43, or 0.42, and even more preferably 0.41 or 0.40.

[0016] (Embodiment 2: Camera Module) The camera module according to the second embodiment includes the imaging lens system described above and an imaging element disposed at the focal position of the imaging lens system and converting light collected through the imaging lens system into an electrical signal, thereby providing a wide-angle, compact, and high-resolution camera module.

[0017] Next, examples corresponding to the imaging lens system according to the first embodiment and the camera module according to the second embodiment will be described with reference to the drawings. Example 1 1 is a cross-sectional view showing the configuration of a camera module 10 of Example 1. Specifically, camera module 10 includes an imaging lens system 11 and an imaging element 12. Imaging lens system 11 and imaging element 12 are housed in a housing (not shown).

[0018] The imaging element 12 is an element that converts received light into an electrical signal, and is, for example, a CCD image sensor or a CMOS image sensor. The imaging element 12 is disposed at the imaging position (focal position) of the imaging lens system 11.

[0019] The imaging lens system 11 according to Example 1 is composed of, in order from the object side to the image side, a front group Gf consisting of a first lens L1, a second lens L2, and a third lens L3, an aperture stop (STOP), and a rear group Gr consisting of a fourth lens L4, a fifth lens L5, a sixth lens L6, and a seventh lens L7. The imaging plane of the imaging lens system 11 is indicated by IMG. If necessary, an optical filter (such as an infrared transmission filter, a visible / infrared bandpass filter, or an infrared cut filter) may be disposed between the imaging lens system 11 and the imaging element 12. In this specification, an example in which an infrared cut filter (IRCF) is disposed between the imaging lens system 11 and the imaging element 12 will be described.

[0020] The first lens L1 is a meniscus lens with negative power. The object-side surface S1 of the first lens L1 has a spherical shape with a convex surface facing the object side. The image-side surface S2 of the first lens L1 has a spherical shape with a concave surface facing the image side.

[0021] The second lens L2 is a meniscus lens with negative power. The object-side surface S3 of the second lens L2 has an aspheric shape with a convex surface facing the object side. The image-side surface S4 of the second lens L2 has an aspheric shape with a concave surface facing the image side.

[0022] The third lens L3 has positive power. The object-side surface S5 of the third lens L3 has an aspheric shape with a convex surface facing the object side. The image-side surface S6 of the third lens L3 also has an aspheric shape with a convex surface facing the image side.

[0023] The aperture stop STOP is an aperture that determines the F-number (F-number, Fno) of the lens system, and is disposed between the third lens L3 and the fourth lens L4.

[0024] The fourth lens L4 has positive power. The object-side surface S9 of the fourth lens L4 has an aspheric shape with a convex surface facing the object side. The image-side surface S10 of the fourth lens L4 also has an aspheric shape with a convex surface facing the image side.

[0025] The fifth lens L5 has negative power. The object-side surface S11 of the fifth lens L5 has an aspheric shape with a concave surface facing the object side. The object-side surface S11 of the fifth lens L5 has an inflection point at a height of 1.142 mm from the optical axis OA. The image-side surface S12 of the fifth lens L5 has an aspheric shape with a concave surface facing the image side.

[0026] The sixth lens L6 has positive power. The object-side surface S13 of the sixth lens L6 has an aspheric shape with a convex surface facing the object side. The image-side surface S14 of the sixth lens L6 also has an aspheric shape with a convex surface facing the image side. The image-side surface S14 of the sixth lens L6 has an inflection point at a height of 1.397 mm from the optical axis OA.

[0027] The seventh lens L7 is a meniscus lens with positive power. The object-side surface S15 of the seventh lens L7 has an aspheric shape with a convex surface facing the object side. The image-side surface S16 of the seventh lens L7 has an aspheric shape with a concave surface facing the image side. The image-side surface S16 of the seventh lens L7 has inflection points at heights of 0.620 mm, 1.882 mm, and 2.860 mm from the optical axis OA.

[0028] The infrared cut filter (IRCF) is a filter for cutting light in the infrared region. When designing the imaging lens system 11, the infrared cut filter is treated as an integral part of the imaging lens system 11. However, the infrared cut filter is not an essential component of the imaging lens system 11. The infrared cut filter is disposed on the image side of the seventh lens L7. Furthermore, a sensor cover glass may be placed between the infrared cut filter and the imaging element 12 to prevent dust from adhering to the imaging element 12.

[0029] Table 1 shows lens data for each lens surface in the imaging lens system 11 of Example 1. Table 1 presents the lens data, such as the radius of curvature (mm) of each surface, the surface spacing (mm) on the optical axis OA, the refractive index nd for the d-line, and the Abbe number vd for the d-line. In Table 1, surfaces marked with an asterisk (*) are aspherical. In the imaging lens system 11 of Example 1, the F-number is 2.0, and the total angle of view is 210°.

[0030] [Table 1]

[0031] The aspheric shapes used on the lens surfaces are as follows: Z is the amount of sag, c is the inverse of the radius of curvature, k is the conic coefficient, and r is the ray height from the optical axis OA. The aspheric coefficients of the 4th, 6th, 8th, 10th, 12th, 14th, and 16th orders are α4, α6, α8, and α 10 , α 12 , α 14 , α 16 When this is the case, it is expressed by the following equation:

number

[0032] Table 2 shows aspherical coefficients for defining the aspherical shape of the aspherical lens surface in the imaging lens system 11 of Example 1. In Table 2, for example, "-7.74E-04" corresponds to "-7.74×10 -4The same applies to the numerical expressions in the following tables.

[0033] [Table 2]

[0034] Next, aberrations will be described with reference to the drawings. Figure 2 shows diagrams of spherical aberration (longitudinal aberration), curvature of field, and distortion in the imaging lens system 11 of Example 1. In the longitudinal aberration diagram of Figure 2(A), the horizontal axis indicates the position where the light ray intersects with the optical axis OA, and the vertical axis indicates the height of the light ray passing through the entrance pupil. Figure 2(A) also shows the simulation results for light rays with wavelengths of 420 nm, 550 nm, and 680 nm. In the field curvature diagram of Figure 2(B), the horizontal axis represents the distance along the optical axis OA, and the vertical axis represents the image height (angle of view). In the field curvature diagram of Figure 2(B), Sag represents the image formation position of the sagittal ray bundle, and Tan represents the image formation position of the tangential ray bundle. Figure 2(B) also shows the simulation results for light with a wavelength of 550 nm. In the distortion diagram of Figure 2(C), the horizontal axis represents image distortion (%) and the vertical axis represents image height (angle of view). Figure 2(C) also shows the simulation results for light with a wavelength of 550 nm.

[0035] Example 2 3 is a cross-sectional view showing a camera module 10 according to Example 2. In the imaging lens system 11 according to Example 2, the object-side surface S11 of the fifth lens L5 does not have an inflection point, the image-side surface S14 of the sixth lens L6 has an inflection point at a position 1.530 mm above the optical axis OA, the object-side surface S15 of the seventh lens L7 has an inflection point at a position 3.060 mm above the optical axis OA, and the image-side surface S16 of the seventh lens L7 has inflection points at positions 0.337 mm, 1.485 mm, and 2.790 mm above the optical axis OA. The imaging lens system 11 according to Example 2 has the same configuration as that of Example 1, except for the inflection points of the object-side surface S11 of the fifth lens L5, the image-side surface S14 of the sixth lens, and the object-side surface S15 and the image-side surface S16 of the seventh lens L7, and therefore a description thereof will be omitted. Below, characteristic data of the imaging lens system 11 according to Example 2 will be described.

[0036] Table 3 shows lens data for each lens surface of the imaging lens system 11 according to Example 2. The items shown in Table 3 are the same as those in Table 1, and therefore their explanation will be omitted. Furthermore, the imaging lens system 11 of Example 2 has an F-number of 2.0 and a total angle of view of 210°.

[0037] [Table 3]

[0038] Table 4 shows aspherical coefficients for defining the aspherical shape of the aspherical lens surface in the imaging lens system 11 of Example 2. In Table 4, the aspherical shape adopted for the lens surface is expressed by the same formula as in Example 1.

[0039] [Table 4]

[0040] 4 shows diagrams of spherical aberration (longitudinal aberration), field curvature, and distortion in the imaging lens system 11 of Example 2. The explanation of each aberration diagram shown in Fig. 4 is the same as that in Fig. 2, and therefore will not be repeated.

[0041] Example 3 5 is a cross-sectional view showing a camera module 10 according to Example 3. In the imaging lens system 11 according to Example 3, the object surface S11 of the fifth lens L5 has an inflection point at a position 1.104 mm above the optical axis OA, the image side surface S14 of the sixth lens L6 has an inflection point at a position 1.345 mm above the optical axis OA, and the image side surface S16 of the seventh lens L7 has inflection points at positions 0.682 mm and 1.797 mm above the optical axis OA. The imaging lens system 11 according to Example 3 has the same configuration as that of Example 1, except for the inflection points of the object side surface S11 of the fifth lens L5, the image side surface S14 of the sixth lens L6, and the image side surface S16 of the seventh lens L7, and therefore a description thereof will be omitted. Below, characteristic data of the imaging lens system 11 according to Example 3 will be described.

[0042] Table 5 shows lens data for each lens surface of the imaging lens system 11 according to Example 3. The items shown in Table 5 are the same as those in Table 1, and therefore their explanation will be omitted. Furthermore, the imaging lens system 11 of Example 3 has an F-number of 2.0 and a total angle of view of 210°.

[0043] [Table 5]

[0044] Table 6 shows aspherical coefficients for defining the aspherical shape of the aspherical lens surface in the imaging lens system 11 of Example 3. In Table 6, the aspherical shape adopted for the lens surface is expressed by the same formula as in Example 1.

[0045] [Table 6]

[0046] 6 shows diagrams of spherical aberration (longitudinal aberration), field curvature, and distortion in the imaging lens system 11 of Example 3. The explanation of each aberration diagram shown in FIG. 6 is the same as that in FIG. 2, and therefore will not be repeated.

[0047] Table 7 shows the total optical length TTL of the imaging lens system 11, the focal length f of the entire optical system of the imaging lens system 11, the focal length f1 of the first lens L1, the focal length f2 of the second lens L2, the focal length f3 of the third lens L3, the focal length f4 of the fourth lens L4, the focal length f5 of the fifth lens L5, the focal length f6 of the sixth lens L6, the focal length f7 of the seventh lens L7, the value of |f12 / f|, the value of f4 / f, the value of nd1, and the value of (L1-STOP) / TTL. In Table 7, the total optical length and focal length are in mm. The focal lengths shown in Table 7 were calculated using the d-line.

[0048] [Table 7]

[0049] In Examples 1 to 3, the imaging lens system 11 satisfies the above conditional expression (1), so that the diameter of the first lens L1 can be reduced while maintaining the angle of view of the imaging lens system 11, thereby realizing a wide-angle yet compact imaging lens system 11. Furthermore, because the third lens L3 and the fourth lens L4 have positive power, it is possible to correct chromatic aberration of magnification that occurs in the first lens L1 and the second lens L2, and it is possible to achieve high resolution in the imaging lens system 11. Furthermore, because the image-side surface S14 of the sixth lens L6 is convex toward the image side and has an inflection point, it is possible to shorten the overall optical length of the imaging lens system 11. This makes it possible to provide a wide-angle yet compact imaging lens system 11 that also has high resolution. Specifically, in Examples 1 to 3, the ratios D / TTL of the effective diameter D of the object-side surface S1 of the first lens L1 to the total optical length TTL of the imaging lens system 11 were 0.362, 0.358, and 0.362, respectively, enabling the diameter of the first lens L1 to be reduced. Furthermore, in Examples 1 to 3, the ratios TTL / f of the total optical length TTL of the imaging lens system 11 to the focal length f of the entire optical system of the imaging lens system 11 were 9.796, 10.302, and 9.696, respectively, enabling the total optical length TTL of the imaging lens system 11 to be shortened. Furthermore, in Examples 1 to 3, the total angle of view was 210°, and the imaging lens system 11 had a wide angle of view that was sufficiently wide for vehicle sensing. Furthermore, in Examples 1 to 3, various aberrations were suitably reduced, as shown in FIGS. 2, 4, and 6, enabling the imaging lens system 11 to have high resolution.

[0050] Furthermore, in Examples 1 to 3, the value of f4 / f satisfies the above conditional expression (2), so that the total optical length TTL of the imaging lens system 11 can be shortened, which contributes to making the imaging lens system more compact. In fact, in Examples 1 to 3, the ratios TTL / f are 9.796, 10.302, and 9.696, respectively, which realizes a shortened total optical length TTL of the imaging lens system 11.

[0051] Furthermore, in Examples 1 to 3, the value of nd1 satisfies the above conditional expression (3), so that the diameter of the first lens L1 can be reduced, and the imaging lens system can be made compact. In fact, in Examples 1 to 3, the ratios D / TTL are 0.362, 0.358, and 0.362, respectively, and the diameter of the first lens L1 can be reduced.

[0052] In addition, in Examples 1 to 3, the image-side surface S16 of the seventh lens L7 is concave toward the image side, and the object-side surface S15 and the image-side surface S16 of the seventh lens L7 have aspheric shapes, and at least one of the object-side surface S15 and the image-side surface S16 of the seventh lens L7 has at least one inflection point. This makes it possible to appropriately correct field curvature and distortion in the seventh lens L7, thereby achieving a high-resolution imaging lens system 11. In fact, in Examples 1 to 3, various aberrations can be appropriately reduced, as shown in FIGS. 2, 4, and 6.

[0053] Furthermore, in Examples 1 to 3, the value of (L1-STOP) / TTL satisfies the above conditional expression (4), thereby shortening the total optical length TTL of the imaging lens system 11 and achieving a compact imaging lens system 11. In fact, in Examples 1 to 3, the ratios TTL / f are 9.796, 10.302, and 9.696, respectively, and a reduction in the total optical length TTL of the imaging lens system 11 is achieved.

[0054] Furthermore, by providing the camera module 10 with the imaging lens system 11, it is possible to provide a camera module 10 that is wide-angle, compact, and has high resolution.

[0055] (Embodiment 3) FIG. 9 is a schematic diagram of a vehicle 40 equipped with an in-vehicle system including an imaging device 50 including an imaging lens system 11 according to the first or second embodiment and an imaging element 12 that converts light collected through the imaging lens system 11 into an electrical signal. As shown in the figure, the imaging device 50 can be mounted on the vehicle 40, and FIG. 9 illustrates an example of the mounting position of the imaging device 50 on the vehicle 40. The imaging device 50 mounted on the vehicle 40 can also be called an in-vehicle camera and can be installed in various locations on the vehicle 40. For example, the first imaging device 50a may be installed on or near the front bumper as a camera that monitors the front of the vehicle 40 while the vehicle 40 is traveling. The second imaging device 50b that monitors the front of the vehicle 40 may be installed near an inner rearview mirror inside the vehicle 40. The third imaging device 50c may be installed on the dashboard or in the instrument panel as a camera that monitors the driver's driving status. The fourth imaging device 50d may be installed at the rear of the vehicle 40 to monitor the rear of the vehicle 40. The imaging devices 50a and 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 includes imaging devices installed in various positions, such as a left side camera that captures images of the left rear side and a right side camera that captures images of the right rear side.

[0056] An image signal of an image captured by the imaging device 50 may be output to an information processing device 42 and / or a display device 43, etc., within the vehicle 40. The information processing device 42 and the display device 43, together with the imaging device 50, constitute an in-vehicle system. The information processing device 42 within the vehicle 40 includes a device that processes the image signal acquired by the imaging device 50 and recognizes various objects in the captured image to assist the driver in driving. The information processing device 42 may include, but is not limited to, a navigation system, a collision damage mitigation braking system, a vehicle-to-vehicle distance control device, a lane departure warning system, etc. The display device 43 displays an image processed and output by the information processing device 42, but can also receive an image signal directly from the imaging device 50. The display device 43 may be, but is not limited to, a liquid crystal display (LCD), an organic electroluminescence (EL) display, or an inorganic EL display. The display device 43 can display, to a driver or other occupant, an image signal output from the imaging device 50, which captures an image from a position difficult for the driver to view, such as a rear camera.

[0057] Fig. 10 shows the configuration of an imaging device 50 that constitutes the in-vehicle system of Fig. 9. As shown in the figure, the imaging device 50 according to one embodiment includes a control unit 52, a storage unit 54, and a camera module 10.

[0058] The control unit 52 controls the camera module 10 and processes the electrical signal output from the image sensor 12 of the camera module 10. The control unit 52 may be configured as, for example, a processor. The control unit 52 may also include one or more processors. The processor may include a general-purpose processor that loads a specific program to execute 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 IC is also called an application-specific integrated circuit (ASIC). The processor may include a programmable logic device. A programmable logic device is also called a programmable logic device (PLD). The PLD may include a field-programmable gate array (FPGA). The control unit 52 may be either an SoC (system-on-a-chip) or a SiP (system in a package) in which one or more processors work together.

[0059] The storage unit 54 stores various information or parameters related to the operation of the imaging device 50. The storage unit 54 may be configured with, for example, a semiconductor memory or the like. 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 parameters, etc., used by the control unit 52 to perform detection processing based on the captured images. The storage unit 54 may be included in the control unit 52.

[0060] As described above, the camera module 10 captures an image of a subject formed via the imaging lens system 11 with the imaging element 12 and outputs the captured image. The image captured by the camera module 10 is also referred to as a captured image.

[0061] The imaging element 12 may be configured, for example, as a CMOS (Complementary Metal Oxide Semiconductor) image sensor or a CCD (Charge Coupled Device). The imaging element 12 has an imaging surface on which a plurality of pixels are arranged. Each pixel outputs a signal specified by a current or voltage according to the amount of incident light. The signal output by each pixel is also referred to as imaging data.

[0062] The imaging data may be read by the camera module 10 for all pixels and imported into the control unit 52 as a captured image. A captured image read out for all pixels is also referred to as a maximum captured image. The imaging data may be read by the camera module 10 for some pixels and imported as a captured image. In other words, the imaging data may be read out from pixels in a predetermined capture range. The imaging data read out from pixels in the predetermined capture range may be imported as a captured image. The predetermined capture range may be set by the control unit 52. The camera module 10 may acquire the predetermined capture range from the control unit 52. The image sensor 12 may capture an image of a predetermined capture range from the subject image formed via the imaging lens system 11.

[0063] It should be noted that the present invention is not limited to the above-described embodiments, and modifications can be made as appropriate without departing from the spirit of the present invention. For example, the applications of the imaging lens system of the present invention are not limited to vehicle-mounted cameras and surveillance cameras, and it can also be used for other applications, such as being mounted on small electronic devices such as mobile phones. [Explanation of symbols]

[0064] 10 Camera Module 11 Imaging lens system 12 Image sensor 40 Vehicles (moving objects) 42 Information processing equipment (processing equipment) 43 Display device (output device) 50 Imaging device 52 Control section L1 First lens L2 Second lens L3 Third lens L4 4th lens L5 Fifth lens L6 6th lens L7 7th lens STOP Aperture Gf front group Gr rear group IRCF Infrared Cut Filter IMG Image plane OA optical axis

Claims

1. The lens comprises, in order from the object side to the image side, a first lens having a convex object side surface facing the object side and negative power, a second lens having a concave image side surface facing the image side and negative power, a third lens having positive power, a stop, a fourth lens having a convex image side surface facing the image side and positive power, a fifth lens having negative power, a sixth lens having a convex image side surface facing the image side and having an inflection point, and a seventh lens having a convex object side surface facing the object side and positive power. When a composite focal length of the first lens and the second lens is defined as f12 and a focal length of the entire optical system is defined as f, the optical system satisfies the following conditional expression (1): Imaging lens system. |f12 / f|<1.5...(1)

2. When the focal length of the fourth lens is defined as f4, the following conditional expression (2) is satisfied:

2. The imaging lens system according to claim 1, wherein: 2.8<f4 / f<3.0...(2)

3. 2. The imaging lens system according to claim 1, wherein the following conditional expression (3) is satisfied when the refractive index of the first lens with respect to the d-line is defined as nd1. nd1>1.8...(3)

4. the seventh lens has an image side surface that is concave toward the image side. The imaging lens system according to claim 1 .

5. the object side surface and the image side surface of the seventh lens have an aspherical shape, and at least one of the object side surface and the image side surface of the seventh lens has at least one inflection point. The imaging lens system according to claim 1 .

6. 2. The imaging lens system according to claim 1, wherein, when a total optical length of the imaging lens system is defined as TTL and a distance on the optical axis from a vertex of the object-side surface of the first lens to the aperture stop is defined as L1-STOP, the imaging lens system satisfies the following conditional expression (4): (L1-STOP) / TTL<0.45...(4)

7. 7. A camera module comprising: the imaging lens system according to claim 1; and an imaging element that converts light collected through the imaging lens system into an electrical signal.

8. An in-vehicle system mounted on a vehicle, The camera module according to claim 7; an information processing device that processes a captured image output from the imaging element of the camera module and recognizes an object in the captured image; An in-vehicle system comprising:

9. A moving body equipped with the in-vehicle system according to claim 8, the in-vehicle system further includes an output device that outputs information to an occupant; The mobile body is characterized in that the information processing device is configured to output the recognition information of the object to the output device.

Images