Camera module, imaging system, and mobile object

Abstract

To provide a camera module, an imaging system, and a mobile object that can suppress the propagation of vibration between housings, ensure desired vibration performance, and prevent noise.SOLUTION: In a camera module according to the present invention, vibration propagation limiting means for limiting the propagation of vibration is provided in a vibration propagation path along which vibration from a first lens 31 vibrated by a vibration mechanism 60 propagates in this order to a first housing 23, a second housing 24, and a third housing 25. The vibration propagation limiting means includes washers 84, 89 interposed between heads 80a, 85a of screws 80, 85 and housings 24, 25, and cushioning materials 90, 92 interposed between the joint surfaces of housings 23, 24, 25.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a camera module such as an in-vehicle camera mounted on a vehicle such as an automobile, an imaging system, and a mobile object equipped with an imaging system. [Background technology]

[0002] Conventionally, automobiles have been equipped with on-board cameras to support parking and prevent collisions through image recognition, and attempts have also been made to apply them to autonomous driving. In addition, camera modules such as such on-board cameras generally include a lens unit having a lens group consisting of multiple lenses arranged along an optical axis, a lens barrel that houses and holds this lens group, and an aperture member arranged between at least one of the lenses in the lens group (see, for example, Patent Document 1).

[0003] In addition, such lens units may be attached to a mounting portion such as the front grille of a vehicle (automobile), with the lens closest to the object exposed to the outside. In such cases, foreign matter such as water droplets, muddy water, ice, snow, and frost easily adheres to the surface of the lens. If this happens, it is necessary to remove the foreign matter to ensure a clear field of view for observation using the lens unit.

[0004] In recent years, foreign matter adhering to the surface of a lens (or lens cover) has been removed by vibrating (ultrasonic vibration) the lens (or lens cover) with a vibrating body. For example, in Patent Document 2, a vibrating device for removing foreign matter such as water droplets and dust adhering to a dome-shaped cover (lens cover) is provided in a camera equipped with a lens unit.

[0005] Specifically, as shown in Figure 8, such a vibration device 102 is provided in a camera that has an imaging unit 105 with a lens 106 and a circuit including an imaging element built in at the top of the camera body 103, and is equipped with a dome-shaped transparent cover 111, a cylindrical vibrating body 112 to which the cover 111 is fixed, and a piezoelectric element 113 that is fixed to the vibrating body 112 and vibrates the cover 111 via the vibrating body 112. The vibrating body 112 has a cylindrical portion 114 having a first end 114a located on the cover 111 side and a second end 114b located on the opposite side from the cover 111, a cylindrical first connecting portion 115 connected to the first end 114a of the cylindrical portion 114 and consisting of a cylinder with an inner diameter larger than that of the cylindrical portion 114, a first ring-shaped portion 116 interposed between the first connecting portion 115 and the cover 111 and having an inner diameter smaller than that of the first connecting portion 115, a second connecting portion 117 connected to the second end 114b of the cylindrical portion 114 and consisting of a cylinder with an outer diameter smaller than that of the cylindrical portion 114, and a second ring-shaped portion 118 interposed between the second connecting portion 117 and the piezoelectric element 113 and having an outer diameter larger than that of the second connecting portion 117.

[0006] In such a vibration device 102, by driving the piezoelectric element 113 to ultrasonically vibrate the cover 111 via the vibrating body 112, the movement and atomization of droplets can be more effectively achieved, or foreign matter adhering to the surface of the cover 111 can be removed. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-231993 [Patent Document 2] Patent No. 6977784 Summary of the Invention [Problem to be solved by the invention]

[0008] Incidentally, all of the components of such a compact camera module, including camera body 103 and vibration device 102, are housed within housing 130. In this case, housing 130 may be constructed by joining multiple housing parts together for reasons such as ease of assembly of the camera components. In particular, when housing 130 is constructed, for reasons of ease of assembly or design, from a cylindrical first housing that forms an accommodation space therein for accommodating vibrating device 102 and a lens unit including lens 106 and a lens barrel, a substantially thin-walled, dish-shaped second housing that forms a recess that mainly accommodates a board portion on which an imaging element of an image sensor module (imaging module) constituting imaging unit 105 is mounted, and a cylindrical third housing that forms an accommodation space therein for accommodating most of the image sensor module and part of an extension from the image sensor module, one problem may arise.

[0009] In other words, in the split-casing structure described above, the casings must be joined together, for example, with screws. However, especially when the casings are made of different materials, vibrations of the lens or cover vibrated by the vibration device are transmitted sequentially through the joint surfaces and screws between the casings, from the first casing closest to the object to the second casing and then to the third casing closest to the image. This vibration transmission can degrade vibration energy, reduce vibration performance, and reduce the vibration displacement of the lens or cover, potentially making it impossible to atomize water droplets or the like adhering to the lens or cover. Furthermore, this vibration transmission can also cause noise due to impacts and resonance between the casings.

[0010] Figure 9 shows experimental data by the inventors, showing the vibration displacement (unit: μm) of the lens or cover caused by a vibration device attached to a first housing, when the housings have a rectangular cross section and are fastened together at their four corners with screws, for different states in which the housings are made of different materials (for example, the first housing is made of stainless steel (SUS304), the second housing is made of engineering plastic (PPS resin), and the third housing is made of aluminum alloy (A5052)). That is, when there is only the first housing (when the second and third housings are not joined), the vibration displacement of the lens or cover is the largest (approximately 35 μm in the figure), but when the second housing is fastened and joined to the image side of the first housing, the vibration displacement of the lens or cover decreases to nearly 30 μm, and when the third housing is further fastened and joined to the image side of the second housing (when the first, second, and third housings are all fastened and joined to each other), the vibration displacement of the lens or cover decreases significantly to approximately 5 μm. In this way, it can be seen that the vibration energy decreases significantly as the housings are successively joined to the image side.

[0011] The present invention has been made in consideration of the above circumstances, and aims to provide a camera module, an imaging system, and a moving body that can suppress the propagation of vibration between housings, ensure desired vibration performance, and prevent noise. [Means for solving the problem]

[0012] In order to solve the above problems, the present invention provides a camera module including a lens group in which a plurality of lenses are arranged along the optical axes of the lenses, a lens barrel that houses and holds the lens group, and an image sensor that converts light collected through the lens group into an electrical signal, a cylindrical first housing that defines an accommodation space therein for receiving the lens barrel that accommodates and holds the lens group; a second housing coupled to an image side of the first housing and forming a recess for receiving a substrate on which the image sensor is mounted so that the image sensor faces the lens group; a cylindrical third housing coupled to the image side of the second housing and surrounding an imaging module including the substrate from the outside; a vibration mechanism provided in the first housing and having a vibrating body for vibrating a first lens located closest to the object side among the lens group; Equipped with The present invention is characterized in that a vibration propagation limiting means for limiting the propagation of vibration is provided in a vibration propagation path along which vibration from the first lens vibrated by the vibration mechanism propagates in sequence to the first housing, the second housing, and the third housing.

[0013] According to the above-described configuration of the present invention, since the vibration propagation limiting means is provided in the vibration propagation path along which the vibration from the first lens vibrated by the vibration mechanism propagates in sequence to the first housing, the second housing, and the third housing, it is possible to prevent the vibration energy from deteriorating due to the vibration propagation and the resulting deterioration of vibration performance. In other words, by suppressing the propagation of vibration between the housings, the desired vibration performance (vibration performance that enables the atomization of water droplets or the like adhering to the lens or cover) can be ensured, and noise due to impacts and resonance between the housings can also be prevented.

[0014] In the above configuration, "limiting the propagation of vibration" means suppressing or blocking the propagation of vibration. "Vibration propagation path" refers to any path that can allow the propagation of vibration waves within the material that makes up the housing. The vibration propagation limiting means may be provided at any one or more positions in the vibration propagation path, but it is preferable to provide multiple vibration propagation limiting means at positions as close as possible to the object side.

[0015] In addition, the above-described configuration of the present invention preferably further includes a screw having a shank with a thread formed thereon to be screwed onto a threaded portion of one housing to fasten the housings together, and a head formed at the end of the shank and abutting against the other housing, and the vibration propagation limiting means preferably includes a washer interposed between the head of the screw and the other housing. This arrangement, in particular, places the washer at the screw fastening location that is likely to become a vibration propagation path, thereby efficiently and effectively limiting vibration propagation. Here, "fastening the housings together" refers to fastening any two of the first to third housings together, and is not limited to fastening adjacent housings together. For example, it also includes fastening the first housing to the third housing with a screw. The washer may be made of any material, including highly elastic materials, as long as it can limit vibration propagation. Examples of suitable materials include rubber and silicone. Alternatively, materials such as plastic are also possible. A combination of multiple materials, such as metal and rubber, is also possible. Using rubber or silicone washers in conjunction with metal washers (e.g., stacking them together) allows you to control (e.g., even out) the pressure on the washers.

[0016] In the above-described configuration of the present invention, the vibration propagation limiting means preferably includes a buffer material inserted between the joint surfaces of the housings. This allows the buffer material to be inserted at the joints of the housings, which are particularly likely to become vibration propagation paths, thereby efficiently and effectively limiting vibration propagation. Examples of such buffer materials include Kapton (registered trademark) and EPDM (ethylene propylene rubber), but plastic materials are also possible.

[0017] The above-described configuration of the present invention is particularly useful in cases where the first, second, and third housings are made of different materials and vibrations are easily propagated.

[0018] The present invention also provides an in-vehicle system having the above-mentioned camera module, and a mobile body equipped with the in-vehicle system. Such in-vehicle systems and mobile bodies can achieve the same effects as the above-mentioned camera module. Note that the term "mobile body" refers to any object that can move, such as a vehicle. [Effects of the Invention]

[0019] According to the camera module of the present invention, the presence of the vibration propagation limiting means makes it possible to prevent deterioration of vibration energy due to vibration propagation and a drop in vibration performance. In other words, by suppressing the propagation of vibration between housings, it is possible to ensure the desired vibration performance and prevent noise. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a plan view of a camera module according to an embodiment of the present invention; [Figure 2] FIG. 2 is a cross-sectional view taken along line AA in FIG. [Figure 3] FIG. 2 is a cross-sectional view taken along line BB in FIG. [Figure 4] This is experimental data showing the vibration displacement of the first lens caused by the vibration mechanism provided in the first housing, in a state where a housing with a rectangular cross section is fastened with screws at its four corners with washers and cushioning material interposed individually at each location as vibration propagation limiting means, and in which the first to third housings made of different materials are joined in stages. [Figure 5] This is experimental data showing the vibration displacement of the first lens caused by the vibration mechanism provided in the first housing, in a state where a housing with a rectangular cross section is fastened with screws at its four corners with washers and cushioning material interposed individually at multiple locations as vibration propagation limiting means, and in which the first to third housings made of different materials are joined in stages. [Figure 6] 1 is a schematic diagram of a vehicle as a moving body on which an imaging system (on-board system) including a camera module according to an embodiment of the present invention is mounted. [Figure 7]FIG. 7 is a block diagram showing the configuration of an imaging device that constitutes the imaging system of FIG. 6. [Figure 8] FIG. 1 is a schematic cross-sectional view of a conventional camera module. [Figure 9] This is experimental data showing the vibration displacement of the lens or lens cover caused by a vibration device installed on the first housing in a conventional state where a housing with a rectangular cross section is fastened at its four corners with screws, when the first to third housings made of different materials are joined in stages. DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. This embodiment contributes to the achievement of "9. Industry, innovation and infrastructure" of the Sustainable Development Goals (SDGs) advocated by the United Nations, which states, "9.1 Develop quality, reliable, sustainable and resilient infrastructure, including regional and transborder infrastructure, to support economic development and human well-being, with a focus on affordable and equitable access for all."

[0022] Fig. 1 is a plan view of a camera module 300 according to one embodiment of the present invention, Fig. 2 is a schematic cross-sectional view of the camera module 300 taken along line AA in Fig. 1, and Fig. 3 is a schematic cross-sectional view of the camera module 300 taken along line BB in Fig. 1. The camera module described below is particularly a camera module such as an in-vehicle camera, which is fixedly installed on the outer surface of a vehicle, for example, with wiring drawn into the vehicle and connected to a display or other device.

[0023] As shown in FIGS. 2 and 3, the camera module 300 of this embodiment is configured by accommodating various optical elements in a housing formed by joining a plurality of housing parts. Specifically, camera module 300 includes, as optical elements, lens group L in which a plurality of lenses are arranged along the optical axes of the lenses, a cylindrical lens barrel 22 that houses and holds lens group L, and image sensor 304 that converts light collected through lens group L into an electrical signal. The housing is made up of a first housing 23 in the shape of a rectangular tube that forms an accommodation space inside to accommodate lens barrel 22 that houses and holds lens group L, a second housing 24 in the shape of a rectangular tube and approximately a thin dish that forms a recess 24g that houses a board 309 on which image sensor 304 is mounted so that image sensor 304 faces lens group L, and determines the position of image sensor 304 in the direction of the optical axis, and a third housing 25 in the shape of a rectangular tube that surrounds image sensor module 310 including board 309 from the outside, and an extension 310A extending from image sensor module 310 protrudes outward from third housing 25. The housings 23, 24, and 25 are made of different materials, for example, the first housing 23 is made of stainless steel (SUS304), the second housing 24 is made of engineering plastic (PPS resin), and the third housing 25 is made of aluminum alloy (A5052). The imaging module 310 is formed by joining, for example, the upper board 309 on which the imaging element 304 is mounted and a lower board on which a circuit for performing image processing is mounted.

[0024] The image-side (lower side in FIG. 1) ends of lens barrel 22 and first housing 23 are supported by second housing 24. The length of second housing 24 in the optical axis direction is shorter than that of first housing 23. The optical axis is indicated by O, and the direction perpendicular to this optical axis O is the radial direction.

[0025] First housing 23 is disposed radially outward of lens barrel 22, and second housing 24 is disposed closer to the image side (lower side in FIG. 1) than first housing 23. Lens barrel 22, first housing 23, second housing 24, and third housing 25 are disposed coaxially. A rectangular plate-shaped inner flange portion 24a is formed at the upper end of the second housing 24, and a convex portion 24b that protrudes toward the object side (upward in Figure 1) is formed at the radial center of this inner flange portion 24a, and a through hole 24c is formed at the radial center of this convex portion 24b.

[0026] Furthermore, a step 24d is formed on the upper surface of the inner flange 24a, and the lower end of the first housing 23 is fitted into this step 24d, thereby positioning the first housing 23 relative to the second housing 24 in the radial direction and the optical axis direction.

[0027] Furthermore, the lens unit 20 including the lens group L and the lens barrel 22 includes a plurality of (for example, six) lenses 31, 32, 33, 34, 35, and 36 arranged in order from the object side. The lens 31 is a first lens 31 located closest to the object side, and this first lens 31 is provided in the first housing 23 and held by a lens holding portion 50, which will be described later. Five lenses 32 , 33 , 34 , 35 , and 36 arranged closer to the image side than the first lens 31 are provided inside the lens barrel 22 .

[0028] Furthermore, a cylindrical protrusion 27 that protrudes toward the image side (downward in FIG. 1) is formed at the lower end of lens barrel 22, and this protrusion 27 is inserted into and fitted into a through-hole 24c provided in second housing 24. As a result, lens barrel 22 and second housing 24 are arranged coaxially and coincident with optical axis O.

[0029] Furthermore, the first lens 31 located closest to the object side is a glass lens, and the lenses 32 to 36 are resin lenses, but this is not limiting (for example, the lens 31 may be a resin lens). Furthermore, the surfaces of the lenses 31 to 36 may be provided with an anti-reflection film, a hydrophilic film, a water-repellent film, or the like, as required.

[0030] The multiple lenses 31 to 36 fixed to and supported by the lens barrel 22 are arranged with their optical axes aligned, and the lenses 31 to 36 are lined up along a single optical axis O to form a group of lenses L used for imaging.

[0031] In this embodiment, the first housing 23 is disposed radially outward from the lens barrel 22. The first housing 23 is made of metal such as SUS and includes a rectangular cylindrical housing main body 23a, a top plate portion 23b in the shape of a rectangular plate that is short in the radial direction and formed integrally with the housing main body 23a at the upper end of the housing main body 23a, and a locking portion 23c that is formed integrally with the top plate portion 23b at the inner peripheral edge of the top plate portion 23b. The thickness of the top plate portion 23b (thickness in the optical axis direction) is thinner than the thickness of the housing main body 23a (thickness in the radial direction).

[0032] The locking portion 23c includes a generally cylindrical protruding portion 23d formed to protrude from the inner peripheral edge of the top plate portion 23b toward the object side (upper side in FIG. 1), and a pressing portion 23e bent radially inward from the upper end of the protruding portion 23d. An inclined surface 23f inclined with respect to the optical axis O is formed along the circumferential direction on the pressing portion 23e. Then, inclined surface 23f presses the surface edge of first lens 31, thereby fixing first lens 31. In other words, in a state in which lens group L is assembled and housed within first housing 23 and lens barrel 22, inclined surface 23f of pressing portion 23e presses first lens 31, which is located closest to the object side of lens group L, and fixes it to the object-side end of first housing 23 in the optical axis direction.

[0033] Furthermore, an inner flange portion 26 having an opening with a diameter smaller than that of sixth lens 36 is provided at the image side end (the lower end in FIG. 1) of lens barrel 22. A plurality of lenses 31-36 constituting lens group L within first housing 23 and lens barrel 22 are held and fixed in the optical axis direction by this inner flange portion 26 and inclined surface 23f of pressing portion 23e. Further, a filter 99 such as an infrared cut filter is provided on the lower surface of the inner flange portion 26 .

[0034] In this embodiment, a ring-shaped lens holding portion 50 that holds the first lens 31 is provided. The lens holder 50 is manufactured by turning a metal such as stainless steel into a thin ring shape. The lens holder 50 has, on its inner periphery, a cylindrical inner circumferential surface 50a and a toric surface 50b that is perpendicular to the inner circumferential surface 50a, with the inner circumferential surface 50a and the toric surface 50b being formed into an L-shaped cross section. The inner circumferential surface 50a is disposed coaxially with the optical axis O, and the toric surface 50b is disposed perpendicular to the optical axis O. In addition, the lens holding portion 50 has an inner surface 50c that is perpendicular to the annular surface 50b and is arranged coaxially with the optical axis O, and this inner surface 50c is arranged closer to the image (lower in Figure 1) than the inner surface 50a and has a smaller inner diameter dimension than the inner surface 50a.

[0035] In addition, the inner diameter dimension of the inner surface 50c of the ring-shaped lens holding portion 50 is larger than the outer diameter dimension of the lens barrel 22, so that the upper end of the lens barrel 22 is positioned inside the inner surface 50c of the lens holding portion 50. Furthermore, the lens holder 50 is joined to the first housing 23. That is, the outer peripheral surface 50d of the lens holder 50 abuts the inner periphery of the protrusion 23d of the first housing 23 with almost no gap, whereby the lens holder 50 fits into the locking portion 23c of the first housing 23. In this way, the lens holder 50 is joined to the first housing 23 having the locking portion 23c. The lens holder 50 joined to the first housing 23 has an axis that coincides with the optical axis O, and is positioned in the optical axis direction.

[0036] The lens holder 50 also holds the first lens 31. That is, the inner peripheral surface 50a of the lens holder 50 abuts tightly against the outer peripheral surface of the first lens 31, thereby positioning the first lens 31 in the radial direction and disposing it coaxially with the optical axis O. The annular surface 50b of the lens holder 50 abuts tightly against the flat bottom surface 31a of the first lens 31 facing the image side, thereby positioning the first lens 31 in the optical axis direction.

[0037] Furthermore, lenses 32 to 36, which are arranged closer to the image than the first lens 31, are held by the lens barrel 22 so that their optical axes are aligned, and the lens barrel 22 is arranged coaxially with the second housing 24 and aligned with the optical axis O, so that the first lens 31 and lenses 32 to 36, which are arranged closer to the image than the first lens 31, are arranged coaxially or with an eccentricity of less than a predetermined amount.

[0038] In this embodiment, a vibration mechanism 60 for vibrating the first lens 31 is provided. The vibration mechanism 60 includes a vibrator 61 that ultrasonically vibrates, and a vibrating body 62 that transmits the ultrasonic vibration of the vibrator 61 to the first lens 31. The vibration mechanism 60 is housed in the first housing 23, positioned radially inward from the first housing 23 and radially outward from the lens barrel 22. The vibrator 61 is formed in the shape of an annular plate, and is provided inside the housing main body 23a of the first housing 23. The vibrator 61 is formed of, for example, a piezoelectric element. The vibration mechanism 60 having the vibrator 61 is separated from the second housing 24 by a predetermined gap s to avoid resonance due to vibration (resonance and the resulting noise).

[0039] The vibrating body 62 includes a donut-shaped disk-shaped mounting portion 62a, and a main body portion 62b that extends from the mounting portion 62a toward the object side (upward in FIG. 1), has an outer diameter and an inner diameter that continuously change in the axial direction (optical axis direction), has a generally cylindrical shape with bulges and constrictions, and has an S-shaped cross section. The vibrator 61 is fixed to the lower surface of the mounting portion 62a, and the upper end side of the main body portion 62b is integrally formed with the lens holding portion 50 described above.

[0040] In such vibration mechanism 60, vibrator 61 ultrasonically vibrates at a predetermined frequency, causing vibrating body 62 to ultrasonically vibrate. When vibrating body 62 vibrates, first lens 31 ultrasonically vibrates at the same frequency via lens holding part 50, because vibrating body 62 is integrated with lens holding part 50, thereby removing foreign matter such as water droplets, muddy water, ice, snow, and frost from lens surface 31b of first lens 31.

[0041] The lens holding part 50 is fitted into the top panel part 23b (locking part 23c) of the first housing 23, but the thickness of the top panel part 23b is thinner than the thickness of the housing main body 23a, and the top panel part 23b functions as a damper, so that vibrations of the lens holding part 50 are not easily transmitted to the housing main body 23a. Therefore, vibrations are not easily transmitted to the second housing 24 fitted into the housing main body 23a, and as a result, vibrations are not easily transmitted to the lens barrel 22 fitted into the second housing 24, and therefore to the lenses 32 to 36, and deterioration of optical performance caused by displacement of the lenses 32 to 36 due to vibrations can be suppressed.

[0042] In addition, in this embodiment, the lens unit 20 is composed of the first housing 23, the first lens 31 held in the first housing 23, the lens barrel 22, the lenses 32 to 36 held in the lens barrel 22, the lens holding portion 50, the vibration mechanism 60, etc. The camera module 300 of this embodiment is composed of this lens unit 20, a second housing 24 that fits into the first housing 23 of the lens unit 20, and a third housing 25 that fits into the second housing 24 and houses the imaging module.

[0043] The second housing 24 and the third housing 25 house therein an imaging module 310 including a board 309 on which an imaging element 304 (image sensor) is mounted. Specifically, the imaging module 310 occupies most of the inner space of the second and third housings 24, 25, and is disposed in the center of the inside of the third housing 25 with the board 309 on which the imaging element 304 (image sensor) is mounted being received and positioned in the recess 24g of the second housing 24.

[0044] Image sensor 304 as a package sensor is disposed inside second housing 24 facing filter 99, and is disposed in a position where it receives an image of an object formed by lens unit 20. Image sensor 304 is equipped with a CCD, CMOS, or the like, and converts light that is collected and reaches it through lens unit 20 into an electrical signal. The converted electrical signal is then converted into analog data or digital data, which are components of image data captured by the camera.

[0045] The third housing 25 also includes a drive circuit board 305 therein. The drive circuit board 305 is a board having a drive circuit that applies a voltage of a predetermined frequency to the piezoelectric element 61 of the vibration mechanism 60 to drive it. The drive circuit board 305 and the vibrator (piezoelectric element) 61 are connected by wiring 306 formed of an FPC or the like and passed through a wiring hole 24f formed in the inner flange portion 24a of the second housing 24.

[0046] As described above, with the substrate 309 on which the image sensor 304 is mounted received in the recess 24g, the second housing 24 has a seal member 70 interposed between it and the third housing 25 (at the joint between the second housing 24 and the third housing 25) to keep the internal spaces of the housings 24, 25 communicating with each other airtight, and is fastened to the first housing 23 with screws 80, as clearly shown in FIG. 3. In this case, the screws 80 are fastened at the four corners of the housings 23, 24, which have rectangular cross sections. In addition, in this case, the inside of the first housing 23 is densely packed with components including the lens unit 20 and the vibration mechanism 60, as described above, and assembly is performed in order from the first housing 23 side to the second housing 24 and the third housing 25 side. Therefore, the screw 80 is screwed into the threaded portion 83 of the first housing 23 from the second housing 24 side, and the head 80a of the screw 80 is positioned on the second housing 24 side. That is, the screw 80 has a shaft portion 80b with threads formed thereon that is screwed into the screw portion 83 of the first housing 23, and a head portion 80a formed at the end of the shaft portion 80b and abutted against the side of the second housing 24.

[0047] 3, the second housing 24 is also fastened to the third housing 25 by screws 85. In this case, too, the screws 85 are fastened at the four corners of the housings 24, 25, each having a rectangular cross section, and the screws 85 are threaded into the threaded portion 87 of the second housing 24 from the third housing 25 side, with the head 85a of the screw 80 positioned on the third housing 25 side. That is, the screw 85 has a shank 85b formed with a thread that screws into the threaded portion 87 of the second housing 24, and a head 85a formed at the end of the shank 85b and abutting against the third housing 25 side.

[0048] Furthermore, in this embodiment, a vibration propagation limiting means for limiting the propagation of vibration is provided in a vibration propagation path along which vibration from the first lens 31 vibrated by the vibration mechanism 60 propagates in sequence to the first housing 23, the second housing 24, and the third housing 25. Specifically, particularly in this embodiment, as the vibration propagation limiting means, washers 84 made of rubber or silicone are interposed between the heads 80 a of all four screws 80 and the second housing 24, and washers 89 made of rubber or silicone are interposed between the heads 85 a of all four screws 85 and the third housing 25.

[0049] Furthermore, in this embodiment, as vibration propagation limiting means, a buffer material 90 made of Kapton (registered trademark; polyimide film) is inserted in the joint surface (contact surface) between the first housing 23 and the second housing 24, and a buffer material 92 made of EPDM (ethylene propylene rubber) is inserted in the joint surface (contact surface) between the second housing 24 and the third housing 254.

[0050] In addition to the screws and the joint surface, the lens holder may be considered as a vibration propagation path, and in addition to the buffer material and washer, adhesive or the like may be considered as a vibration propagation limiting means.

[0051] 4 shows experimental data by the present inventors, which shows the vibration displacement of the first lens 31 caused by the vibration mechanism 60 in each state where the first to third housings 23, 24, 25 made of different materials are joined in stages, with the rectangular housings 23, 24, 25 fastened at their four corners with screws 80, 85, with the washers 84, 89 and cushioning materials 90, 92 described above interposed at each location as vibration propagation limiting means. The solid line in the figure represents the case of "no measures" in which no vibration propagation limiting means is provided, and is the experimental data described above with reference to FIG. In addition, dashed line a indicates a case in which cushioning material 90 is inserted at the joint surface between the first housing 23 and the second housing 24 (cushioning material 92 and washers 84, 89 are not provided), dotted line b indicates a case in which washers 84 are provided on four screws 80 (cushioning materials 90, 92 and washer 89 are not provided), three-dotted line c indicates a case in which cushioning material 92 is inserted at the joint surface between the second housing 24 and the third housing 25 (cushioning material 90 and washers 84, 89 are not provided), and two-dotted line d indicates a case in which washers 89 are provided on four screws 85 (cushioning materials 90, 92 and washer 84 are not provided). In all cases, the amount of vibration displacement of the first lens 31 decreases as the state shifts from one with only the first housing 23 (a state in which the second and third housings 24, 25 are not joined) to one in which the second housing 24 is fastened and joined to the image side of the first housing 23, to one in which the third housing 25 is further fastened and joined to the image side of the second housing 24 (a state in which the first, second, and third housings 23, 24, 25 are all fastened and joined to one another), but it can be seen that the reduction in the amount of vibration displacement is small when cushioning materials 90, 92 or washers 84, 89 are provided as vibration propagation limiting means. In particular, it was found that vibration propagation can be effectively limited when washers 84, 89 are provided on the screws 80, 85.

[0052] FIG. 5 shows experimental data obtained by the inventors in which washers 84, 89 and buffer materials 90, 92 were individually placed at multiple locations as vibration propagation limiting means. The solid line in the figure represents the "no measures" case in which no vibration propagation limiting means was provided, and corresponds to the experimental data described above with reference to FIG. 9. The two-dot chain line b+d represents a combination of lines b and d in FIG. 4, in which washers 84 were provided on four screws 80 and washers 89 were also provided on four screws 85. The three-dot chain line a+b+c+d represents a combination of all the cases in FIG. 4, in which washers 84 were provided on four screws 80 and washers 89 were also provided on four screws 85, buffer materials 90 were inserted at the interface between the first housing 23 and the second housing 24, and buffer materials 92 were inserted at the interface between the second housing 24 and the third housing 25. In either case, the decrease in the vibration displacement of the first lens 31 can be significantly suppressed.

[0053] As described above, according to this embodiment, vibration propagation limiting means 84, 89, 90, and 92 are provided in the vibration propagation path along which vibrations from first lens 31 vibrated by vibration mechanism 60 propagate in sequence to first housing 23, second housing 24, and third housing 25, thereby preventing deterioration of vibration energy and a drop in vibration performance due to vibration propagation. In other words, by suppressing the propagation of vibration between housings 23, 24, and 25, desired vibration performance (vibration performance that enables atomization of water droplets and the like adhering to lens 31) is ensured, and noise due to impact and resonance between housings 23, 24, and 25 can also be prevented.

[0054] FIG. 6 schematically illustrates a vehicle 240 as a moving body equipped with an in-vehicle system (imaging system) equipped with an imaging device 250 including the camera module 300 of FIGS. 1 to 3 . As illustrated, the imaging device 250 can be mounted on the vehicle 240, and FIG. 6 illustrates an example of an arrangement illustrating the mounting position of the imaging device 250 on the vehicle 240. The imaging device 250 mounted on the vehicle 240 can also be called an in-vehicle camera, and can be installed in various locations on the vehicle 240. For example, the first imaging device 250a may be disposed on or near the front bumper as a camera that monitors the front of the vehicle 240 while the vehicle 240 is traveling. The second imaging device 250b that monitors the front may be disposed near an inner rearview mirror inside the vehicle 240. The third imaging device 250c may be disposed on the dashboard or in the instrument panel as a camera that monitors the driver's driving status. The fourth imaging device 250d may be installed at the rear of the vehicle 240 to monitor the rear of the vehicle 240. The imaging devices 250a and 250b can be called front cameras. The third imaging device 250c can be called an in-camera. The fourth imaging device 250d can be called a rear camera. The imaging device 250 is not limited to these, and includes imaging devices installed in various positions, such as a left side camera that images the left rear side and a right side camera that images the right rear side.

[0055] An image signal of an image captured by the imaging device 250 may be output to an information processing device (control unit) 242 and / or a display device (output device) 243 in the vehicle 240. The information processing device 242 and the display device 243, together with the imaging device 250, constitute an in-vehicle system. The information processing device 242 in the vehicle 240 includes a device that processes the image signal (captured image) acquired by the imaging device 250 and recognizes the image (recognizes objects in the captured image) to assist the driver in driving. The information processing device 242 is configured to output recognition information of objects in the captured image to the display device 243, and examples of such devices include, but are not limited to, a navigation device, a collision damage mitigation braking device, a vehicle-to-vehicle distance control device, and a lane departure warning device. The display device 243 displays the image processed and output by the information processing device 242, but can also receive an image signal directly from the imaging device 250. Furthermore, display device 243 may employ, but is not limited to, a liquid crystal display (LCD), an organic electroluminescence (EL) display, or an inorganic EL display. Display device 243 can display to the driver (can output information to passengers) an image signal output from imaging device 250 that captures an image from a position that is difficult for the driver to view, such as a rear camera.

[0056] Fig. 7 shows the configuration of an imaging device that constitutes the in-vehicle system of Fig. 6. As shown in the figure, an imaging device 250 according to one embodiment includes a control unit 252, a storage unit 254, and the camera module 300 shown in Figs. 1 to 3 described above.

[0057] The control unit 252 controls the camera module 300 and processes the electrical signal output from the image sensor 304 of the camera module 300. The control unit 252 may be configured as, for example, a processor. The control unit 252 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 252 may be either an SoC (system-on-a-chip) or a SiP (system in a package) in which one or more processors work together. In addition, the control unit 252 may have the same functions as the information processing device 242 described above, and may, for example, process the captured image output from the image sensor 304 and recognize the object in the captured image.

[0058] The storage unit 254 stores various information or parameters related to the operation of the imaging device 250. The storage unit 254 may be configured with, for example, a semiconductor memory or the like. The storage unit 254 may function as a work memory for the control unit 252. The storage unit 254 may store captured images. The storage unit 254 may store various parameters and the like for the control unit 252 to perform detection processing based on the captured images. The storage unit 254 may be included in the control unit 252.

[0059] As described above, the camera module 300 captures an image of a subject formed via the lens unit 20 with the image sensor 304 and outputs the captured image. The image captured by the camera module 300 is also referred to as a captured image.

[0060] The image sensor 304 may be configured, for example, as a CMOS (Complementary Metal Oxide Semiconductor) image sensor or a CCD (Charge Coupled Device). The image sensor 304 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.

[0061] The imaging data may be read by the camera module 300 for all pixels and captured by the control unit 252 as a captured image. A captured image read by all pixels is also referred to as a maximum captured image. The imaging data may be read by the camera module 300 for some pixels and captured as a captured image. In other words, the imaging data may be read from pixels in a predetermined capture range. The imaging data read from pixels in the predetermined capture range may be captured as a captured image. The predetermined capture range may be set by the control unit 252. The camera module 300 may acquire the predetermined capture range from the control unit 252. The image sensor 304 may capture an image of a predetermined capture range from the subject image formed via the lens unit 20.

[0062] The present invention is not limited to the above-described embodiments and can be modified in various ways without departing from the spirit of the invention. For example, the shapes of the lens, housing, lens barrel, etc. are not limited to those of the above-described embodiments. Furthermore, some or all of the above-described embodiments may be combined, or part of the configuration of one of the above-described embodiments may be omitted, without departing from the spirit of the invention. [Explanation of symbols]

[0063] 20 Lens unit 22 Telescope tube 23 First enclosure 24 Second enclosure 25 Third Enclosure 31 First Lens 60 Vibration mechanism 80,85 screws 84, 89 Washer (vibration propagation limiting means) 90,92 Cushioning material (vibration propagation limiting means) 300 Camera Module 304 Image sensor 310 Imaging Module L lens group

Claims

1. A camera module comprising: a lens group in which a plurality of lenses are arranged along the optical axes of the lenses; a lens barrel that houses and holds the lens group; and an image sensor that converts light collected through the lens group into an electrical signal, a cylindrical first housing that defines an accommodation space therein for receiving the lens barrel that accommodates and holds the lens group; a second housing coupled to an image side of the first housing and forming a recess for receiving a substrate on which the image sensor is mounted so that the image sensor faces the lens group; a cylindrical third housing coupled to the image side of the second housing and surrounding an imaging module including the substrate from the outside; a vibration mechanism provided in the first housing and having a vibrating body for vibrating a first lens located closest to the object side among the lens group; Equipped with A camera module characterized in that a vibration propagation limiting means for limiting the propagation of vibration is provided in a vibration propagation path along which vibration from the first lens vibrated by the vibration mechanism propagates sequentially to the first housing, the second housing, and the third housing.

2. a screw having a shaft portion on which a thread is formed to be screwed into a threaded portion of one of the housings in order to fasten the housings together, and a head portion formed at an end of the shaft portion and abutted against the other housing; 2. The camera module according to claim 1, wherein the vibration propagation restricting means includes a washer interposed between the head of the screw and the other housing.

3. 3. The camera module according to claim 1, wherein the vibration propagation restricting means includes a buffer material inserted between the joint surfaces of the housings.

4. 4. The camera module according to claim 3, wherein the first, second, and third housings are made of different materials.

5. An in-vehicle system mounted on a vehicle, The camera module according to claim 1; a control unit 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:

6. A vehicle equipped with the in-vehicle system according to claim 5 and an output device that outputs information to a passenger, The control unit is configured to output recognition information of the object to the output device.

Images