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

Abstract

To provide a compact imaging lens system with a high resolution, a camera module, an on-vehicle system, and a moving body.SOLUTION: An imaging lens system 11 comprises, in order from an object side to an image side: a first lens L1 that has negative power and has an object-side surface having a convex surface facing the object side; a second lens L2 that has negative power and has an image-side surface having a concave surface facing the image side; a third lens L3 that has positive power and has an object-side surface having a convex surface facing the object side; a diaphragm STOP; a fourth lens L4 that has positive power; a fifth lens L5 that has negative power and has an object-side surface having a concave surface facing the object side; a sixth lens L6 that has positive power and has an image-side surface having a convex surface facing the image side; and a seventh lens L7 that has positive power and has an object-side surface having a convex surface facing the object side. The fifth lens L5 and the sixth lens L6 constitute a cemented lens having negative composite power.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, sensing functions for detecting people and objects have been required for vehicle-mounted cameras, and image sensors have become larger with higher resolution. Accordingly, the imaging lens systems mounted on vehicle-mounted cameras and the like tend to become larger. On the other hand, due to the demand for omnidirectional sensing around the vehicle, vehicle-mounted cameras are increasingly being mounted in spatially limited locations such as side mirrors. Therefore, there is a demand for miniaturization of vehicle-mounted cameras. Patent Document 1 describes a lens system consisting of seven lenses that is mounted on an on-vehicle camera or the like. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-102291 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the imaging lens system described in Patent Document 1, since the sixth lens is a biconcave lens, the light beam emitted from the sixth lens heads off-axis. Therefore, in order to keep the angle of incidence of the light beam incident on the sensor surface small, it is necessary to increase the power of the seventh lens adjacent to the sixth lens. This causes large astigmatism and curvature of field in areas with high image heights, resulting in poor imaging performance. In addition, the imaging lens system described in Patent Document 1 has a problem in that the ratio (hereinafter referred to as "peripheral illumination") of the amount of light focused on the periphery of the imaging surface to the amount of light focused on the center of the imaging surface (the intersection point between the imaging surface and the optical axis) is low.

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

[0006] An imaging lens system of one embodiment includes, in order from the object side to the image side, a first lens having negative power and a convex surface on the object side facing the object side, a second lens having negative power and a concave surface on the image side facing the image side, a third lens having positive power and a convex surface on the object side facing the object side, a stop, a fourth lens having positive power, a fifth lens having a concave surface on the object side facing the object side, a sixth lens having positive power and a convex surface on the image side facing the image side, and a seventh lens having positive power and a convex surface on the object side facing the object side, The fifth lens and the sixth lens form a cemented lens having a negative composite power. Effect of the Invention

[0007] According to the present invention, it is possible to provide a compact and high-resolution imaging lens system, a camera module, an in-vehicle system, and a moving body. [Brief description of the drawings]

[0008] [Figure 1] 1 is a cross-sectional view showing a configuration of a camera module and an imaging lens system according to a first embodiment. [Diagram 2] 3A to 3C are diagrams showing spherical aberration (longitudinal aberration) and curvature of field in the imaging lens system of Example 1. [Diagram 3] FIG. 11 is a cross-sectional view showing the configuration of a camera module and an imaging lens system according to a second embodiment. [Figure 4] 11A to 11C are diagrams showing spherical aberration (longitudinal aberration) and curvature of field in the imaging lens system of Example 2. [Diagram 5] FIG. 11 is a cross-sectional view showing the configuration of a camera module and an imaging lens system according to a third embodiment. [Figure 6]11A to 11C are diagrams showing spherical aberration (longitudinal aberration) and curvature of field in the imaging lens system of Example 3. [Figure 7] FIG. 11 is a cross-sectional view showing the configuration of a camera module and an imaging lens system according to a fourth embodiment. [Figure 8] 11A to 11C are diagrams showing spherical aberration (longitudinal aberration) and curvature of field in the imaging lens system of Example 4. [Figure 9] 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 10] 10 is a block diagram showing a configuration of an imaging device constituting the in-vehicle system of FIG. 9. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. This embodiment can realize a highly reliable system, particularly in a sensing system, and ensures healthy lives and promotes welfare for all people of all ages, and targets "3.6 By 2020, halve the number of global road traffic fatalities and injuries." in "3. Health and well-being for all" of the Sustainable Development Goals (SDGs) advocated by the United Nations. In addition, this embodiment contributes to the development of resilient infrastructure, and targets "9. Build resilient infrastructure, promote industry, innovation and infrastructure, and promote economic development and human welfare, with a focus on affordable and equitable access for all." in "9. Infrastructure and infrastructure." in the Sustainable Development Goals (SDGs) advocated by the United Nations. (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 negative power and a convex surface on the object side facing the object side, a second lens having negative power and a concave surface on the image side facing the image side, a third lens having positive power and a convex surface on the object side facing the object side, a stop, a fourth lens having positive power, a fifth lens having a concave surface on the object side facing the object side, a sixth lens having positive power and a convex surface on the image side facing the image side, and a seventh lens having positive power and a convex surface on the object side facing the object side, The fifth lens and the sixth lens form a cemented lens having a negative composite power.

[0010] This makes it possible to provide a compact, high-resolution imaging lens system. Specifically, the image side surface of the sixth lens faces the convex surface toward the image side, and the object side surface of the seventh lens faces the convex surface toward the object side, so that the angle of incidence of light rays incident on the seventh lens can be made small, and the occurrence of astigmatism can be suppressed. Also, the object side surface of the seventh lens faces the convex surface toward the object side, so that the occurrence of field curvature in areas with high image heights can be suppressed, and the peripheral illumination ratio can be increased. Therefore, it is possible to provide a compact, high-resolution imaging lens system.

[0011] Furthermore, when the radius of curvature of the object side surface of the first lens is defined as L1R1 and the focal length of the entire imaging lens system is defined as f, it is preferable to satisfy the following conditional expression (1). 6.0 <L1R1 / f<7.5 ···(1) When the imaging lens system satisfies the above conditional formula (1), the diameter of the first lens can be reduced, and the imaging lens system can be made compact. When the imaging lens system satisfies the above conditional formula (1), the occurrence of lateral chromatic aberration and astigmatism can be suppressed. Specifically, when the value of L1R1 / f is 6.0 or less, the curvature of the image side surface of the first lens becomes too large to make the power of the first lens sufficiently strong, and the manufacturing of the first lens becomes difficult. When the value of L1R1 / f is 7.5 or more, the diameter of the first lens becomes too large, and the imaging lens system cannot be made compact. When the value of L1R1 / f is 7.5 or more, the angle of incidence of off-axis incident light entering the first lens becomes large, and large lateral chromatic aberration and astigmatism occur on the object side surface of the first lens. The value of L1R1 / f is more preferably 6.5 or more and 7.2 or less, more preferably 6.5 or more and 7.15 or less, and even more preferably 6.5 or more and 7.1 or less.

[0012] Furthermore, when the focal length of the first lens of the imaging lens system is defined as f1 and the focal length of the entire imaging lens system is defined as f, it is preferable that the imaging lens system satisfies the following conditional expression (2). 2.5<|f1 / f|<3.5 ...(2) When the imaging lens system satisfies the above conditional expression (2), the diameter of the first lens can be reduced, and the imaging lens system can be made compact. When the imaging lens system satisfies the above conditional expression (2), the occurrence of lateral chromatic aberration, astigmatism, and curvature of field can be suppressed. Specifically, when the value of |f1 / f| is 2.5 or less, the diameter of the first lens can be reduced, but the power of the first lens becomes too strong, and large lateral chromatic aberration, astigmatism, and curvature of field occur in the first lens, and it becomes difficult to correct these aberrations with the second lens to the seventh lens. When the value of |f1 / f| is 3.5 or more, the occurrence of lateral chromatic aberration, astigmatism, and curvature of field in the first lens can be suppressed, but the power of the first lens becomes too weak, and the diameter of the first lens becomes too large, and the imaging lens system cannot be made compact. The value of |f1 / f| is more preferably 2.7 or more, and even more preferably 3.4 or less, or 2.8 to 3.0 or less.

[0013] Furthermore, when the focal length of the first lens is defined as f1 and the focal length of the second lens is defined as f2, it is preferable that the following conditional expression (3) be satisfied. 0.9 <f1 / f2<1.5 ···(3) When the imaging lens system satisfies the above conditional formula (3), the diameter of the first lens can be made small and the occurrence of various aberrations can be suppressed. Specifically, when the value of f1 / f2 is 0.9 or less, the diameter of the first lens can be made small, but the power of the first lens becomes too strong, resulting in large curvature of field in the first lens. Also, when the value of f1 / f2 is 1.5 or more, the occurrence of various aberrations in the first lens can be suppressed, but the negative power of the first lens becomes too weak, resulting in the diameter of the first lens becoming too large. The value of f1 / f2 is more preferably 0.97 or more and 1.45 or less, and even more preferably 0.98 or more and 1.25 or less.

[0014] Furthermore, when the focal length of the seventh lens is defined as f7 and the focal length of the entire imaging lens system is defined as f, it is preferable that the following conditional expression (4) be satisfied. 4.0 <f7 / f<8.0 ···(4) When the imaging lens system satisfies the above conditional formula (4), it is possible to prevent the occurrence of shading and to effectively correct the curvature of field. If the value of f7 / f is 4.0 or less, the power of the seventh lens becomes too strong, resulting in overcorrection of the curvature of field. On the other hand, if the value of f7 / f is 8.0 or more, the power of the seventh lens becomes too weak, resulting in an excessively large angle of incidence of light rays on the sensor surface (image surface), particularly the peripheral portion, and thus causing shading. The value of f7 / f is more preferably 4.8 or more and 7.9 or less, and even more preferably 7.2 or less and 7.0 or less.

[0015] It is preferable that the object side and image side surfaces of the seventh lens have aspheric shapes having an inflection point. By having the object side and image side surfaces of the seventh lens have aspheric shapes having an inflection point, it is possible to appropriately correct field curvature and distortion in the seventh lens, thereby achieving a high-resolution imaging lens system.

[0016] Moreover, the seventh lens is preferably a meniscus lens. Since the seventh lens is a meniscus lens, it is possible to improve the peripheral illumination ratio and effectively correct the curvature of field. Specifically, since the image side surface of the seventh lens faces the concave surface toward the image side, it is possible to correct the curvature of field. Meanwhile, since the object side surface of the seventh lens faces the convex surface toward the object side, it is possible to improve the peripheral illumination ratio. This makes it possible to suppress the decrease in the peripheral illumination ratio caused by the image side surface of the seventh lens facing the concave surface toward the image side.

[0017] (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 making it possible to provide a compact, high-resolution camera module.

[0018] 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 a 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).

[0019] 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 an image forming position (focal position) of the imaging lens system 11.

[0020] The imaging lens system 11 according to the first embodiment is composed of, in order from the object side to the image side, a front group Gf composed of a first lens L1, a second lens L2, and a third lens L3, an aperture stop (STOP), and a rear group Gr composed 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.

[0021] The first lens L1 is a meniscus lens having 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.

[0022] The second lens L2 has a negative power. The object side surface S3 of the second lens L2 has an aspheric shape with a concave 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.

[0023] The third lens L3 has a 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 has an aspheric shape with a convex surface facing the image side.

[0024] The aperture STOP is an aperture that determines the F-number (F number, Fno) of the lens system. The aperture STOP is disposed between the third lens L3 and the fourth lens L4.

[0025] The fourth lens L4 has a positive power. An object side surface S8 of the fourth lens L4 has a spherical shape with a convex surface facing the object side. In addition, an image side surface S9 of the fourth lens L4 has a spherical shape with a convex surface facing the image side.

[0026] The fifth lens L5 has a negative power. The object side surface S10 of the fifth lens L5 has an aspheric shape with a concave surface facing the object side. The image side surface S11 of the fifth lens L5 has an aspheric shape with a concave surface facing the image side.

[0027] The sixth lens L6 has a positive power. The object side surface S12 of the sixth lens L6 has an aspheric shape with a convex surface facing the object side. The image side surface S13 of the sixth lens L6 has an aspheric shape with a convex surface facing the image side.

[0028] The seventh lens L7 is a meniscus lens having a positive power. The object side surface S14 of the seventh lens L7 has an aspheric shape with a convex surface facing the object side. The image side surface S15 of the seventh lens L7 has an aspheric shape with a concave surface facing the image side.

[0029] 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 being integrated with 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.

[0030] Table 1 shows lens data for each lens surface in the imaging lens system 11 of Example 1. In Table 1, the lens data includes 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, a surface marked with an "*" indicates that it is an aspheric surface. In the imaging lens system 11 of Example 1, the F-number is 2.0, and the total angle of view (2ω) is 210°.

[0031] [Table 1]

[0032] The aspheric shape used on the lens surface is expressed as follows: Z is the amount of sag, c is the inverse of the radius of curvature, k is the cone 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 Then, it is expressed by the following equation.

number

[0033] Table 2 shows aspheric coefficients for defining the aspheric shape of the lens surface that is made aspheric in the imaging lens system 11 of Example 1. Note that in Table 2, for example, "-1.30824E-03" corresponds to "-1.30824×10 -3 The same applies to the numerical expressions in the following tables.

[0034] [Table 2]

[0035] Next, aberration will be described with reference to the drawings. Fig. 2 shows a diagram of spherical aberration (longitudinal aberration) and a diagram of curvature of field in the imaging lens system 11 of the first embodiment. In the longitudinal aberration diagram of Fig. 2(A), the horizontal axis indicates the position where the light ray intersects with the optical axis OA, and the vertical axis indicates the passing height of the light ray on the entrance pupil. Fig. 2(A) also shows the simulation results for the e-line, C'-line, and F'-line. In the field curvature diagram of Fig. 2(B), the horizontal axis indicates the distance in the direction of the optical axis OA, and the vertical axis indicates the image height (angle of view). In the field curvature diagram of Fig. 2(B), Sag indicates the image formation position of the sagittal ray bundle, and Tan indicates the image formation position of the tangential ray bundle. Fig. 2(B) also shows the simulation results for the e-line.

[0036] Example 2 3 is a cross-sectional view showing a camera module 10 according to Example 2. In Example 2, the second lens L2 has negative power, the object side surface S3 of the second lens L2 has an aspheric shape with a convex surface facing the object side, and the image side surface S4 of the second lens L2 has an aspheric shape with a concave surface facing the image side. The configuration of the imaging lens system 11 according to Example 2 other than the second lens L2 is the same as that of Example 1, so the description thereof will be omitted. Hereinafter, characteristic data of the imaging lens system 11 according to Example 2 will be described.

[0037] 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, in the imaging lens system 11 of Example 2, the F-number is 2.0, and the total angle of view (2ω) is 210°.

[0038] [Table 3]

[0039] Table 4 shows aspheric coefficients for defining the aspheric shape of the lens surface that is made aspheric in the imaging lens system 11 of Example 2. In Table 4, the aspheric shape adopted for the lens surface is expressed by the same formula as in Example 1.

[0040] [Table 4]

[0041] Fig. 4 shows spherical aberration diagrams (longitudinal aberration diagrams) and field curvature diagrams 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, so the explanation will be omitted.

[0042] Example 3 5 is a cross-sectional view showing a camera module 10 according to Example 3. The imaging lens system 11 according to Example 3 has a lens configuration similar to that of Example 2, and therefore the description thereof will be omitted. Hereinafter, characteristic data of the imaging lens system 11 according to Example 3 will be described.

[0043] 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, in the imaging lens system 11 of Example 3, the F-number is 2.0, and the total angle of view (2ω) is 210°.

[0044] [Table 5]

[0045] Table 6 shows aspheric coefficients for defining the aspheric shape of the lens surface that is made aspheric in the imaging lens system 11 of Example 3. In Table 6, the aspheric shape adopted for the lens surface is expressed by the same formula as in Example 1.

[0046] [Table 6]

[0047] Fig. 6 shows spherical aberration diagrams (longitudinal aberration diagrams) and field curvature diagrams 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, so the explanation will be omitted.

[0048] Example 4 7 is a cross-sectional view showing a camera module 10 according to Example 4. The configuration of an imaging lens system 11 according to Example 4 is the same as that of Example 2, so a description thereof will be omitted. Hereinafter, characteristic data of the imaging lens system 11 according to Example 4 will be described.

[0049] Table 7 shows lens data for each lens surface of the imaging lens system 11 according to Example 4. The items shown in Table 7 are the same as those in Table 1, and therefore their explanation will be omitted. Furthermore, in the imaging lens system 11 of Example 4, the F-number is 2.0, and the total angle of view (2ω) is 210°.

[0050] [Table 7]

[0051] Table 8 shows aspheric coefficients for defining the aspheric shape of the lens surface that is made aspheric in the imaging lens system 11 of Example 4. In Table 8, the aspheric shape adopted for the lens surface is expressed by the same formula as in Example 1.

[0052] [Table 8]

[0053] Fig. 8 shows spherical aberration diagrams (longitudinal aberration diagrams) and field curvature diagrams in the imaging lens system 11 of Example 4. The explanation of each aberration diagram shown in Fig. 8 is the same as that in Fig. 2, so the explanation will be omitted.

[0054] Table 9 shows 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 L1R1 / f, the value of |f1 / f|, the value of f1 / f2, and the value of f7 / f. In Table 9, the unit of focal length is mm. The focal lengths shown in Table 9 were calculated using the e-line.

[0055] [Table 9]

[0056] In Examples 1 to 4, the image side surface of the sixth lens faces the convex surface toward the image side, and the object side surface of the seventh lens faces the convex surface toward the object side, so that a compact and high-resolution imaging lens system can be provided. Specifically, in Examples 1 to 4, as shown in Figs. 2, 4, 6, and 8, various aberrations can be suitably reduced. Therefore, in Examples 1 to 4, the imaging lens system 11 has high resolution. Also, in Examples 1 to 4, the total angle of view (2ω) is 210°, and the imaging lens system 11 has a wide angle of view sufficient for vehicle sensing.

[0057] In addition, in Examples 1 to 4, the value of L1R1 / f satisfies the above conditional formula (1), so that the diameter of the first lens can be made small and the occurrence of lateral chromatic aberration and astigmatism can be suppressed. In fact, in Examples 1 to 4, various aberrations can be suitably reduced, as shown in Figures 2, 4, 6, and 8.

[0058] In addition, in Examples 1 to 4, the value of |f1 / f| satisfies the above conditional expression (2), so that the diameter of the first lens can be made small and the occurrence of lateral chromatic aberration, astigmatism, and curvature of field can be suppressed. In fact, in Examples 1 to 4, various aberrations can be suitably reduced, as shown in Figures 2, 4, 6, and 8.

[0059] In addition, in Examples 1 to 4, the value of f1 / f2 satisfies the above conditional expression (3), so that the diameter of the first lens can be made small and the occurrence of various aberrations can be suppressed. In fact, in Examples 1 to 4, various aberrations can be suitably reduced, as shown in Figures 2, 4, 6, and 8.

[0060] In addition, in Examples 1 to 4, the value of f7 / f satisfies the above conditional expression (4), so that shading can be prevented from occurring and curvature of field can be effectively corrected. In fact, in Examples 1 to 4, various aberrations can be suitably reduced, as shown in Figures 2, 4, 6, and 8.

[0061] In addition, in Examples 1 to 4, the object side and image side surfaces of the seventh lens have aspheric shapes having inflection points, so that the seventh lens can effectively correct field curvature and distortion, thereby realizing a high-resolution imaging lens system. In fact, in Examples 1 to 4, various aberrations can be effectively reduced, as shown in Figures 2, 4, 6, and 8.

[0062] In addition, in Examples 1 to 4, the seventh lens is a meniscus lens, which improves the peripheral illumination ratio and effectively corrects the field curvature. In fact, in Examples 1 to 4, various aberrations can be suitably reduced as shown in Figures 2, 4, 6, and 8.

[0063] Furthermore, by providing the camera module 10 with the imaging lens system 11, it is possible to provide a compact camera module 10 with high resolution.

[0064] (Embodiment 3) FIG. 9 is a schematic diagram of a vehicle 40 equipped with an on-board 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 into an electrical signal. As shown in the figure, the imaging device 50 can be mounted on the vehicle 40, and FIG. 9 is an example of an arrangement illustrating a 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 on-board camera, and can be installed in various places on the vehicle 40. For example, the first imaging device 50a may be arranged on or near the front bumper as a camera that monitors the front when the vehicle 40 is traveling. The second imaging device 50b that monitors the front may be arranged near an inner rearview mirror inside the vehicle 40. The third imaging device 50c may be arranged on the dashboard or in the instrument panel as a camera that monitors the driving situation of the driver. The fourth imaging device 50d may be installed at the rear of the vehicle 40 for rear monitoring 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 the left rear side and a right side camera that captures the right rear side.

[0065] 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 in 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 in 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 includes, but is not limited to, a navigation device, a collision damage mitigation brake device, a vehicle distance control device, and a lane departure warning device. 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 employ, but is not limited to, a liquid crystal display (LCD), an organic EL (Electro-Luminescence) display, and an inorganic EL display. The display device 43 can display an image signal output from the imaging device 50, which captures an image at a position that is difficult for the driver to view, such as a rear camera, to a passenger such as the driver.

[0066] Fig. 10 shows the configuration of an imaging device 50 constituting 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.

[0067] The control unit 52 controls the camera module 10 and processes an electrical signal output from the image sensor 12 of the camera module 10. The control unit 52 may be configured as a processor, for example. The control unit 52 may 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 integrated circuit (ASIC) may also be called an application-specific integrated circuit (ASIC). The processor may include a programmable logic device. The programmable logic device may also be called a programmable logic device (PLD). The PLD may include a field-programmable gate array (FPGA). The control unit 52 may be either a system-on-a-chip (SoC) in which one or more processors work together, or a system in a package (SiP).

[0068] 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 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 and the like for 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.

[0069] As described above, the camera module 10 captures an object image 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 called a captured image.

[0070] 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.

[0071] The imaging data may be read by the camera module 10 for all pixels and taken into the control unit 52 as a captured image. The 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 taken into the control unit 52 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 taken into the capture image. The predetermined capture range may be set by the control unit 52. The camera module 10 may obtain the predetermined capture range from the control unit 52. The imaging element 12 may capture an image of a predetermined capture range of a subject image formed via the imaging lens system 11.

[0072] The present invention is not limited to the above-described embodiments, and can be modified as appropriate without departing from the spirit and scope of the present invention. For example, the imaging lens system of the present invention is not limited to use in vehicle-mounted cameras and surveillance cameras, and can also be used for other purposes, such as being mounted on small electronic devices such as mobile phones. [Explanation of symbols]

[0073] 10 Camera Module 11 Imaging lens system 12 Image sensor 40 Vehicles (mobile objects) 42 Information processing device (processing device) 43 Display device (output device) 50 Imaging device 52 Control section L1 First lens L2 Second lens L3 Third lens L4 4th lens L5 5th lens L6 6th lens L7 7th lens STOP Squeeze Gf front group Gr rear group IRCF Infrared Cut Filter IMG Image plane OA optical axis

Claims

1. The optical system comprises, in order from the object side to the image side, a first lens having negative power and a convex surface on the object side facing the object side, a second lens having negative power and a concave surface on the image side facing the image side, a third lens having positive power and a convex surface on the object side facing the object side, a stop, a fourth lens having positive power, a fifth lens having negative power and a concave surface on the object side facing the object side, a sixth lens having positive power and a convex surface on the image side facing the image side, and a seventh lens having positive power and a convex surface on the object side facing the object side. the fifth lens and the sixth lens form a cemented lens having a negative composite power, Imaging lens system.

2. When a radius of curvature of the object side surface of the first lens is defined as L1R1 and a focal length of the entire imaging lens system is defined as f, the following conditional expression (1) is satisfied:

2. The imaging lens system according to claim 1. 6.0<L1R1 / f<7.5...(1)

3. When the focal length of the first lens is defined as f1 and the focal length of the entire imaging lens system is defined as f, the following conditional expression (2) is satisfied:

2. The imaging lens system according to claim 1. 2.5<|f1 / f|<3.5...(2)

4. 2. The imaging lens system according to claim 1, wherein the following conditional expression (3) is satisfied, where the focal length of the first lens is defined as f1 and the focal length of the second lens is defined as f2: 0.9<f1 / f2<1.5...(3)

5. 2. The imaging lens system according to claim 1, wherein the following conditional expression (4) is satisfied, when a focal length of the seventh lens is defined as f7 and a focal length of the entire imaging lens system is defined as f: 4.0<f7 / f<8.0...(4)

6. the object side surface and the image side surface of the seventh lens have an aspheric shape having an inflection point, 2. The imaging lens system according to claim 1.

7. The imaging lens system according to claim 1 , wherein the seventh lens is a meniscus lens.

8. 8. 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.

9. An in-vehicle system installed in a vehicle, A camera module according to claim 8; 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:

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

Images