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 object-side surface having a convex surface facing the object 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 convex surface facing the object side; a sixth lens L6 that has positive power and has an image-side surface having a concave 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 also tend to become larger. Meanwhile, due to the demand for omnidirectional sensing of the vehicle's surroundings, vehicle-mounted cameras are increasingly being mounted in spatially limited locations such as side mirrors. For this reason, there is a demand for miniaturization of vehicle-mounted cameras. In addition, there is a demand for a smaller diameter of the first lens to reduce the possibility of collision with stones, gravel, and the like. Patent Document 1 describes a lens system that is mounted on an in-vehicle camera or the like and is made up of seven lenses, in which the diameter of the first lens is relatively small. [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, the sixth lens is a biconcave lens, so the light emitted from the sixth lens is directed off-axis. Therefore, in order to reduce the angle of incidence of the light incident on the sensor surface, 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, deteriorating imaging performance.

[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 convex surface on the object side facing the object 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 convex surface on the object side facing the object side, a sixth lens having positive power and a concave 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 convex surface on the object side facing the object 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 convex surface on the object side facing the object side, a sixth lens having positive power and a concave 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, since the sixth lens is a meniscus lens with a concave surface facing the image side, the angle of the off-axis light beams emitted from the sixth lens with respect to the optical axis can be made small. Therefore, even if the power of the seventh lens adjacent to the sixth lens is made small, the angle of the light beams incident on the sensor surface can be made small. In addition, the occurrence of astigmatism and curvature of field in areas with high image heights can be suppressed, and good imaging performance can be maintained. In addition, since the power of the seventh lens is small, the error sensitivity of the seventh lens can also be made low. Therefore, it is possible to provide a compact, high-resolution imaging lens system.

[0011] It is also preferable that the image side surface of the seventh lens has an inflection point. By having an inflection point on the image side surface of the seventh lens, it is possible to suitably correct curvature of field in the seventh lens and realize a high-resolution imaging lens system.

[0012] Furthermore, when the radius of curvature of the object-side surface of the first lens is defined as L1R1 and the distance on the optical axis from the apex of the object-side surface of the first lens to the aperture is defined as L1-STOP, it is preferable that the imaging lens system satisfies the following conditional formula (1): L1R1 / (L1-STOP)<2.0 (1) When the imaging lens system satisfies the above conditional formula (1), the curvature of the object side surface of the first lens can be made tight, and the angle of incidence of the light beam incident on the first lens can be made gentle. This makes it possible to suppress the astigmatism occurring on the object side surface of the first lens to be small. This makes it possible to maintain good imaging performance over the entire field of view. When the value of L1R1 / (L1-STOP) is 2.0 or more, the curvature of the object side surface of the first lens becomes loose, the angle of incidence of the light beam incident on the first lens becomes tight, and large astigmatism occurs on the object side surface of the first lens. The value of L1R1 / (L1-STOP) is more preferably 1.80 or less, 1.70 or less, and further preferably 1.60 or less.

[0013] Furthermore, when the composite focal length of the lens group located on the object side of the aperture is defined as FGF, and the distance on the optical axis from the vertex of the object-side surface of the first lens to the aperture is defined as L1-STOP, it is preferable to satisfy the following conditional expression (2): 2.0<|(L1-STOP) / FGF|<3.0 ···(2) When the imaging lens system satisfies the above conditional expression (2), the imaging lens system can be made compact more reliably. Specifically, in order to reduce the diameter of the first lens, it is necessary to increase the power of the front group (the lens group located closer to the object side than the aperture) of the imaging lens system. However, if the power of the front group is too large, the distortion becomes too large, and it is necessary to increase the size of the rear group (the lens group located closer to the object side than the aperture) in order to correct the distortion. Therefore, if the value of |(L1-STOP) / FGF| is smaller than 2.0, the power of the front group is small, that is, the composite focal length of the front group becomes long, and as a result, the diameter of the first lens becomes large. On the other hand, if the value of |(L1-STOP) / FGF| is larger than 3.0, the power of the front group becomes too large, the distortion becomes too large, and it is necessary to increase the size of the rear group in order to correct the distortion. The value of |(L1-STOP) / FGF| is more preferably 2.3 or more and 2.5 or less, and even more preferably 2.35 or more and 2.45 or less.

[0014] Furthermore, when the focal length of the entire imaging lens system is defined as F and the combined focal length of the fifth and sixth lenses is defined as F56, it is preferable that the imaging lens system satisfies the following conditional expression (3). 5.0<|F56 / F|<12.0 ···(3) When the imaging lens system satisfies the above conditional expression (3), not only the longitudinal chromatic aberration and the chromatic aberration of magnification but also the spherical aberration, the astigmatism, and the higher-order components of the curvature of field can be suitably corrected, and a high-resolution imaging lens system can be realized. When the value of |F56 / F| is 5.0 or less, the spherical aberration and the curvature of field are biased toward the under side (increased in the negative direction). On the other hand, when the value of |F56 / F| is 12.0 or more, the spherical aberration and the curvature of field are biased toward the over side (increased in the positive direction). The value of |F56 / F| is more preferably 5.5 or more and 10.5 or less, and even more preferably 6.5 or more and 8.5 or less. In a cemented lens, when the difference in refractive index between the cemented surfaces is small, the critical angle can be made large, making it difficult for total reflection to occur. As a result, the curvature of the cemented surfaces can be made tight, making it possible to correct spherical aberration, astigmatism, and higher-order components of field curvature.

[0015] Furthermore, when the focal length of the entire imaging lens system is defined as F and the composite focal length of the lens group located on the object side with respect to the aperture stop is defined as FGF, it is preferable that the following conditional expression (4) be satisfied. 2.0<|FGF / F|<3.5 ···(4) When the imaging lens system satisfies the above conditional formula (4), a compact imaging lens system with high resolution can be realized while ensuring a sufficient back focus. Specifically, when the value of |FGF / F| is 2.0 or less, the spherical aberration, coma aberration, and lateral chromatic aberration occurring in the front group become large, and it is necessary to enlarge the rear group in order to correct the spherical aberration, coma aberration, and lateral chromatic aberration diagram. On the other hand, when the value of |FGF / F| is 3.5 or more, the power of the front group becomes small, and it is necessary to enlarge the front group in order to correct the field curvature and distortion while ensuring a sufficient back focus. The value of |FGF / F| is more preferably 2.2 or more and 2.7 or less, and even more preferably 2.3 or more and 2.7 or less.

[0016] In addition, when the composite focal length of the lens group located on the object side of the aperture is defined as FGF, and the composite focal length of the lens group located on the image side of the aperture is defined as RGF, it is preferable that the imaging lens system satisfies the following conditional expression (5): 0.9<|FGF / RGF|<1.5 ···(5) By making the imaging lens system satisfy the above conditional formula (5), it is possible to balance between compactness and high resolution of the imaging lens. Specifically, when the value of |FGF / RGF| is 0.9 or less, the spherical aberration, coma aberration, and lateral chromatic aberration occurring in the front group become large, and it is necessary to enlarge the rear group in order to correct the spherical aberration, coma aberration, and lateral chromatic aberration diagram. On the other hand, when the value of |FGF / RGF| is 1.5 or more, the power of the front group becomes small, and it is necessary to enlarge the front group in order to correct the field curvature and distortion while ensuring a sufficient back focus. The value of |FGF / RGF| is more preferably 0.94 or more and 1.1 or less, and even more preferably 0.95 or more and 1.0 or less.

[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 is a meniscus lens having 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.

[0023] The third lens L3 is a meniscus lens having 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 concave 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 is a meniscus lens having negative power. The object side surface S10 of the fifth lens L5 has an aspheric shape with a convex 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 is a meniscus lens having 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 concave surface facing the image side.

[0028] The seventh lens L7 has a positive power. An object side surface S14 of the seventh lens L7 has an aspheric shape with a convex surface facing the object side. In addition, an image side surface S15 of the seventh lens L7 has an aspheric shape with a convex 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 adopted for 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, r is the ray height from the optical axis OA, and the aspheric coefficients of the 4th, 6th, 8th, 10th, 12th, 14th, and 16th orders are α 4 , α 6 , α 8 , 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, "-5.54772E-03" corresponds to "-5.54772×10 -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 F' line, e line, and C' 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. The configuration of an imaging lens system 11 according to Example 2 is the same as that of Example 1, and therefore a 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 1, and therefore the description thereof will be omitted. The characteristic data of the imaging lens system 11 according to Example 3 will be described below.

[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 1, 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 composite focal length F56, the composite focal length FGF, the composite focal length RGF, the value of L1R1 / (L1-STOP), the value of |(L1-STOP) / FGF|, the value of |F56 / F|, the value of |FGF / F|, and the value of |FGF / RGF|. In Table 9, the focal lengths are calculated using the e-line and are in mm.

[0055] [Table 9]

[0056] In Examples 1 to 4, the sixth lens L6 is a meniscus lens, so that it is possible to provide a compact and high-resolution imaging lens system 11. 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°, so that 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 / (L1-STOP) satisfies the above conditional expression (1), so that the curvature of the object side surface of the first lens L1 can be made tight, and the astigmatism generated on the object side surface of the first lens can be kept small, thereby maintaining good imaging performance over the entire field of view.

[0058] Furthermore, in Examples 1 to 4, the value of |(L1-STOP) / FGF| satisfies the above conditional expression (2), so that the imaging lens system can be made more compact with greater certainty.

[0059] In addition, in Examples 1 to 4, the value of |F56 / F| satisfies the above conditional expression (3), so that not only the longitudinal chromatic aberration and the chromatic aberration of magnification but also the spherical aberration, the astigmatism, and the higher-order components of the curvature of field can be suitably corrected, and a high-resolution imaging lens system can be realized. 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 |FGF / F| satisfies the above conditional expression (4), so that a compact, high-resolution imaging lens system can be realized while ensuring a sufficient back focus. 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 value of |FGF / RGF| satisfies the above conditional expression (5), so that a balance can be achieved between compactness and high resolution of the imaging lens. In fact, in Examples 1 to 4, various aberrations can be suitably reduced, as shown in Figs. 2, 4, 6, and 8.

[0062] 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.

[0063] (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.

[0064] 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.

[0065] 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.

[0066] 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).

[0067] 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.

[0068] 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.

[0069] The imaging element 12 may be composed of, for example, 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 called imaging data.

[0070] 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.

[0071] 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]

[0072] 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 its object side facing the object side, a second lens having negative power and a convex surface on its object side facing the object side, a third lens having positive power and a convex surface on its object side facing the object side, a stop, a fourth lens having positive power, a fifth lens having a convex surface on its object side facing the object side, a sixth lens having positive power and a concave surface on its image side facing the image side, and a seventh lens having positive power and a convex surface on its 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. the seventh lens has an image side surface having an inflection point, 2. The imaging lens system according to claim 1.

3. When a radius of curvature of an object-side surface of the first lens is defined as L1R1 and a distance on an optical axis from a vertex of the object-side surface of the first lens to the aperture stop is defined as L1-STOP, the following conditional expression (1) is satisfied:

2. The imaging lens system according to claim 1. L1R1 / (L1-STOP)<2.0...(1)

4. 2. The imaging lens system according to claim 1 , wherein when a composite focal length of a lens group located on the object side of the aperture is defined as FGF, and a distance on the optical axis from a vertex of the object-side surface of the first lens to the aperture is defined as L1-STOP, the imaging lens system satisfies the following conditional expression (2): 2.0<|(L1-STOP) / FGF|<3.0...(2)

5. 2. The imaging lens system according to claim 1, wherein the following conditional expression (3) is satisfied, when a focal length of the entire imaging lens system is defined as F and a composite focal length of the fifth lens and the sixth lens is defined as F56: 5.0<|F56 / F|<12.0...(3)

6. 2. The imaging lens system according to claim 1, wherein the following conditional expression (4) is satisfied, when a focal length of the entire imaging lens system is defined as F and a composite focal length of a lens group located on the object side with respect to the aperture is defined as FGF: 2.0<|FGF / F|<3.5...(4)

7. 2. The imaging lens system according to claim 1, wherein when a composite focal length of a lens group located on the object side of the aperture is defined as FGF and a composite focal length of a lens group located on the image side of the aperture is defined as RGF, the imaging lens system satisfies the following conditional expression (5): 0.9<|FGF / RGF|<1.5...(5)

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