Lens unit, camera module, imaging system, and moving body

Abstract

To provide a lens unit capable of preventing transmitted light, which has transmitted through an outer periphery portion of a first lens or between a lens barrel and the first lens, from being made incident on an imaging element, a camera module, an imaging system, and a moving body.SOLUTION: The lens unit comprises: a first housing 23 on which a first lens 31 is provided; a lens barrel 22 on which a lens provided closer to an image side than the first lens is provided and which is provided radially inside of the first housing; a second housing 24 which is arranged closer to the image side than the first housing and is fitted to the first housing; a vibration mechanism 60 provided between the first housing and the lens barrel; a wiring 306 for applying a driving signal to a vibration source 61; and a wiring hole 24f which is provided in the second housing and through which the wiring is passed. A stray light prevention portion 351 is provided which prevents transmitted light, which has passed through an outer periphery portion of the first lens, from passing between the lens barrel and the vibration mechanism and being made incident on an imaging element 304 in a predetermined range of an image forming surface 304a on which a light beam condensed through a lens group forms an image.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a lens unit constituting an on-board camera mounted on a vehicle such as an automobile, a camera module, an imaging system, and a moving body 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 further attempts have 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 a plurality of lenses arranged along an optical axis, a lens barrel that houses and holds the lens group, and an aperture member disposed between at least one of the lenses in the lens group (for example, see Patent Document 1).

[0003] However, such a lens unit is attached to a mounting portion such as the front grille of a vehicle (automobile), and the first lens located closest to the object is exposed to the outside. Therefore, foreign matter such as water droplets, muddy water, ice, snow, and frost easily adheres to the surface (lens surface) of the first lens, and therefore, in some cases, the first lens is vibrated (ultrasonic vibration) by a vibrating body to remove the foreign matter from the lens surface (lens surface) of the first lens.

[0004] 2. Description of the Related Art There is known a vibration device that is provided in a camera having a lens unit and that removes foreign matter such as water droplets and dust that has adhered to a dome-shaped cover (lens cover) (see, for example, Patent Document 2). As shown in FIG. 10, the vibration device 2 comprises a dome-shaped cover 11, a cylindrical vibrating body 12 to which the cover 11 is fixed, and a piezoelectric element 13 fixed to the vibrating body 12 and vibrating the cover 11 via the vibrating body 12. The vibrating body 12 comprises a cylindrical portion 14 having a first end 14a located on the cover 11 side and a second end 14b located on the opposite side to the cover 11, a cylindrical first connecting portion 15 connected to the first end 14a of the cylindrical portion 14 and made of a cylinder having an inner diameter larger than that of the cylindrical portion 14, and a second connecting portion 15 connected to the cover 11 side of the first connecting portion 15 and made of a cylinder having an inner diameter larger than that of the cylindrical portion 14. The vibrating body 12 has a first ring-shaped portion 16 having an inner diameter smaller than that of the first end 14b of the cylindrical portion 14, and the cover 11 is fixed to the surface facing the cover 11, a second connecting portion 17 connected to the second end 14b of the cylindrical portion 14 and consisting of a cylinder having an outer diameter smaller than that of the cylindrical portion 14, and a second ring-shaped portion 18 fixed to the surface of the second connecting portion 17 opposite to the side to which the cylindrical portion 14 is connected and having an outer diameter larger than that of the second connecting portion 17, and the piezoelectric element 13 is fixed to the surface of the second ring-shaped portion 18 opposite to the side fixed to the second connecting portion 14b, and the cylindrical vibrating body 12 has a substantially S-shaped cross-sectional shape in a radial cross section. In such a vibration device 2, the dome-shaped cover 11 can be vibrated with a larger amplitude, and the movement and atomization of the droplets can be more effectively achieved.

[0005] As described above, the vibration device 2 is equipped with a cylindrical vibrating body 12 and a piezoelectric element 13, and removes foreign matter adhering to the surface of the light-transmitting part (cover) 11 by fixing the cover 11, which is a light-transmitting part, to the vibrating body 12 and vibrating it ultrasonically. Furthermore, the camera equipped with the vibration device 2 has a camera body 3, and an imaging section 5 having a built-in circuit including an imaging element is provided at the upper end of the camera body 3. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2013-231993 A [Patent Document 2] Patent No. 6977784 Summary of the Invention [Problem to be solved by the invention]

[0007] The applicant is currently developing a camera module that includes a first housing in which a first lens located closest to the object is mounted, a lens barrel arranged radially inward from the first housing and in which lenses other than the first lens are mounted, a second housing arranged on the image side of the first housing and fitted into the first housing, a vibration mechanism arranged between the first housing and the lens barrel for vibrating the first lens, and an image sensor arranged in the second housing for converting light that is focused through lenses including the first lens and reaches the second housing into an electrical signal. In such a camera module, if the lens barrel comes into contact with the first lens and the vibration mechanism, the vibration (ultrasonic vibration) of the first lens caused by the vibration mechanism will be hindered, so it is necessary to provide a certain gap between the lens barrel and the first lens, and between the lens barrel and the vibration mechanism. On the other hand, since the first lens is provided in the first housing, transmitted light that passes through the outer periphery of the first lens and transmitted light (stray light) that passes between the lens barrel and the first lens passes through the gap between the lens barrel and the vibration mechanism. In addition, the second housing has a wiring hole for connecting, via wiring, a piezoelectric element (vibration source) provided in the vibration mechanism to a drive circuit board provided in the second housing for driving the piezoelectric element (vibration source). This results in a problem in that transmitted light (stray light) that passes through the gap is reflected by the lens barrel, wiring hole, wiring, etc., enters the second housing through the wiring hole, and enters a certain range of the imaging surface where the light rays focused through the lens group are imaged, resulting in degradation of image quality.

[0008] The present invention has been made in consideration of the above-mentioned circumstances, and has an object to provide a lens unit, a camera module, an imaging system, and a moving body that can prevent transmitted light that has passed through the outer periphery of the first lens or between the lens barrel and the first lens from entering a predetermined range of the image-forming surface where light rays focused through the lens group are imaged. [Means for solving the problem]

[0009] In order to solve the above problems, the present invention provides a lens unit including a lens group in which a plurality of lenses are arranged along the optical axes of the lenses, and a vibration mechanism having a vibration source that vibrates a first lens that is located closest to an object among the plurality of lenses, a first housing in which the first lens is provided, a lens barrel in which a lens located closer to the image side than the first lens is provided and which is provided radially inward from the first housing, a second housing which is located closer to the image side than the first housing and which fits into the first housing, the vibration mechanism provided between the first housing and the lens barrel, wiring for applying a drive signal to the vibration source, and a wiring hole provided in the second housing through which the wiring passes; The optical system is characterized in that it has a stray light prevention section that prevents transmitted light that has passed through the outer periphery of the first lens and / or transmitted light that has passed between the lens barrel and the first lens from passing between the lens barrel and the vibration mechanism and entering a predetermined range of the image forming plane where the light rays focused through the lens group are imaged.

[0010] In the present invention, even if transmitted light passes between the lens barrel and the vibration mechanism directly or after being reflected by the lens barrel, wiring holes, wiring, etc., the stray light prevention section can prevent the transmitted light from entering a specified range of the imaging plane.

[0011] In addition, in the above-described configuration of the present invention, a drive circuit board for applying a drive signal to the vibration source via the wiring may be provided in the second housing, and the drive circuit board and the vibration source may be connected by the wiring.

[0012] With this configuration, the drive circuit board is provided in the second housing, so the drive circuit board can be protected by the second housing and the wiring can be made shorter compared to when the drive circuit board is provided separately from the lens unit.

[0013] In the above-described configuration of the present invention, the stray light prevention unit may be configured such that a wiring hole provided in the second housing is disposed in a blind spot of a predetermined range on the imaging surface. Here, locating the wiring hole in a blind spot of a specified range on the imaging surface means locating the wiring hole at a position where the transmitted light will not enter the specified range on the imaging surface even if it passes through the gap between the lens barrel and the vibration mechanism and passes through the wiring hole.

[0014] According to this configuration, the stray light prevention unit is configured to place the wiring hole provided in the second housing in a blind spot of a predetermined range of the image formation surface, so that transmitted light passing through the gap between the lens barrel and the vibration mechanism, either directly or by reflection, does not enter the predetermined range of the image formation surface even if it passes through the wiring hole. Therefore, it is possible to prevent transmitted light from entering the predetermined range of the image formation surface.

[0015] In the above-described configuration of the present invention, the stray light prevention unit may be configured such that the second housing is provided with an incidence prevention member that prevents the transmitted light from entering a predetermined range of the imaging plane.

[0016] According to this configuration, the stray light prevention unit is configured so that the second housing is provided with an incidence prevention member that prevents transmitted light from entering a specified range of the image-forming surface. Therefore, even if transmitted light passes through the gap between the lens barrel and the vibration mechanism, either directly or by reflection, the incidence prevention member can prevent the transmitted light from entering the specified range of the image-forming surface.

[0017] In the above-described configuration of the present invention, the stray light prevention section may be configured such that a part of the lens barrel and a part of the vibration mechanism overlap in the optical axis direction and are continuous in the circumferential direction.

[0018] With this configuration, the stray light prevention unit has a configuration in which a part of the lens barrel and a part of the vibration mechanism overlap in the optical axis direction and are continuous in the circumferential direction, so that the transmitted light does not advance beyond this overlapping part toward the image side, thereby preventing the transmitted light from entering a predetermined range of the image plane.

[0019] In the above-described configuration of the present invention, the stray light prevention portion may be configured such that the wiring hole is provided radially outward from the vibration mechanism.

[0020] According to this configuration, the stray light prevention unit has a wiring hole provided radially outward from the vibration mechanism, so that transmitted light passing through the gap between the lens barrel and the vibration mechanism, either directly or by reflection, does not pass through the wiring hole, thereby preventing the transmitted light from entering a predetermined range on the imaging surface.

[0021] The present invention also provides a camera module having the lens unit, an imaging system having the camera module, and a moving body equipped with the imaging system. The imaging system and moving body can also provide the same effects as the lens unit described above. Note that the term "moving body" refers to any object that can move, such as a vehicle. Effect of the Invention

[0022] According to the present invention, it is possible to prevent light that has passed through the outer periphery of the first lens and / or between the lens barrel and the first lens from entering a predetermined range on the imaging plane. [Brief description of the drawings]

[0023] [Figure 1] FIG. 1 is a schematic cross-sectional view of a camera module according to a first embodiment of the present invention. [Diagram 2] FIG. [Diagram 3] FIG. 11 is a schematic cross-sectional view of a camera module according to a second embodiment of the present invention. [Figure 4]FIG. 11 is a schematic cross-sectional view of a camera module according to a third embodiment of the present invention. [Diagram 5] FIG. 10 is a schematic cross-sectional view of a camera module according to a fourth embodiment of the present invention. [Figure 6] FIG. 11 is a schematic cross-sectional view showing a camera module according to a first modified example of the first embodiment. [Figure 7] FIG. 11 is a schematic cross-sectional view showing a camera module according to a second modified example of the first embodiment. [Figure 8] 1 is a schematic diagram of a vehicle as a moving body on which an imaging system (vehicle-mounted system) including a camera module according to an embodiment of the present invention is mounted. [Figure 9] 9 is a block diagram showing a configuration of an imaging device that constitutes the imaging system shown in FIG. 8. [Figure 10] FIG. 11 is a schematic cross-sectional view of a lens unit including a conventional vibrating body. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The embodiment contributes to "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."

[0025] It should be noted that the camera module of this embodiment described below is intended particularly for use as an in-vehicle camera, and is fixedly installed, for example, on the outer surface of a vehicle, with wiring being pulled into the vehicle and connected to a display or other devices.

[0026] (First embodiment) FIG. 1 shows a camera module according to a first embodiment of the present invention, and is a schematic cross-sectional view of the camera module, and FIG. 2 is a perspective view of the camera module. 1 and 2, the camera module 300 of this embodiment includes a lens unit 20. This lens unit 20 includes a cylindrical lens barrel 22 and a square tube-shaped first housing 23 in which this lens barrel 22 is provided.

[0027] The ends of the lens barrel 22 and first housing 23 on the image side (lower side in FIG. 1) are supported by a square cylindrical second housing 24. The length of the second housing 24 in the optical axis direction is shorter than that of the first housing 23, but the lengths of the outer diameter and inner diameter are longer than those of the first housing 23. The optical axis is indicated by O, and the direction perpendicular to this optical axis O is the radial direction.

[0028] The first housing 23 is disposed radially outward from the lens barrel 22, and the second housing 24 is disposed closer to the image side (lower side in FIG. 1) than the first housing 23. The lens barrel 22, the first housing 23 and the second housing 24 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.

[0029] Further, a step portion 24d is formed on the upper surface of the inner flange portion 24a, and the lower end portion of the first housing 23 is fitted into this step portion 24d. As a result, the first housing 23 is positioned relative to the second housing 24 in the radial direction and the optical axis direction.

[0030] Furthermore, the lens unit 20 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 on the image side of the first lens 31 are provided inside the lens barrel 22 .

[0031] In addition, a cylindrical protrusion 27 that protrudes toward the image side (the lower side in FIG. 1) is formed at the lower end of the lens barrel 22, and this protrusion 27 is inserted into and fitted into the through hole 24c provided in the second housing 24. As a result, the lens barrel 22 and the second housing 24 are arranged coaxially and coincident with the optical axis O.

[0032] Furthermore, the first lens 31 located closest to the object side is a glass lens, and the lenses 32 to are plastic lenses, but are not limited to this (for example, the lens 31 may be a plastic lens). Furthermore, on the surfaces of the lenses 31 to , an anti-reflection film, a hydrophilic film, a water-repellent film, or the like is provided as necessary.

[0033] The multiple lenses 31-36 fixed and supported by the first housing 23 and the lens barrel 22 are arranged with their respective optical axes aligned, and the lenses 31-36 are lined up along a single optical axis O to form a single lens group L used for imaging.

[0034] In this embodiment, the first housing 23 is disposed on the outer side of the lens barrel 22 in the radial direction. The first housing 23 is formed from a metal such as SUS, and includes a rectangular cylindrical housing main body 23a, a rectangular plate-shaped top plate portion 23b formed integrally with the housing main body 23a at the upper end of the housing main body 23a, and a locking portion 23c formed integrally with the top plate portion 23b on the inner edge of the top plate portion 23b. The thickness of the top plate portion 23b (thickness in the optical axis direction) is smaller than the thickness of the housing main body 23a (thickness in the radial direction).

[0035] The locking portion 23c includes a generally cylindrical protruding portion 23d formed to protrude from the edge of the inner periphery 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, the inclined surface 23f presses the surface edge of the first lens 31, thereby fixing the first lens 31. In other words, in a state in which the lens group L is assembled and housed within the first housing 23 and the lens barrel 22, the inclined surface 23f of the pressing portion 23e presses the first lens 31 located closest to the object side of the lens group L, and fixes it to the object side end of the first housing 23 in the optical axis direction.

[0036] Furthermore, an inner flange portion 26 having an opening with a diameter smaller than that of sixth lens 36 is provided at the end (the lower end portion in FIG. 1) of lens barrel 22 on the image side, and a flange portion of lens 36 abuts against this inner flange portion 26. Furthermore, lens 32 is adhesively fixed to lens barrel 22, and in this state, optical components such as lenses 33-36 located on the image side of lens 32 are pressed toward the image side by lens 32. Therefore, the optical components such as the lenses 33 to are held and fixed in the optical axis direction by the lens 32 and the inner flange portion . Further, a filter 99 such as an infrared cut filter is provided on the lower surface of the inner flange portion 26 .

[0037] In this embodiment, a ring-shaped lens holder 50 that holds the first lens 31 is provided. The lens holder 50 is manufactured by forming a metal such as SUS into a thin ring shape by lathe cutting. The lens holder 50 has an inner peripheral surface 50a having a cylindrical shape and an annular surface 50b perpendicular to the inner peripheral surface 50a, and the inner peripheral surface 50a and the annular surface 50b are formed to have an L-shaped cross section. The inner peripheral surface 50a is disposed coaxially with the optical axis O, and the annular 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 arranged coaxially with the optical axis O, and this inner surface 50c is arranged closer to the image side (lower side in Figure 1) than the inner surface 50a and has a smaller inner diameter dimension than the inner surface 50a.

[0038] 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. Moreover, the lens holding part 50 is joined to the first housing 23. That is, the outer peripheral surface 50d and the upper surface 50e of the lens holding part 50 are each in contact with the inner periphery of the pressing part 23e of the first housing 23 with almost no gap, whereby the lens holding part 50 is fitted into the top plate part 23b of the first housing 23. In this way, the lens holding part 50 is joined to the first housing 23 having the top plate part 23b. 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.

[0039] Furthermore, the lens holding part 50 holds the first lens 31. That is, an inner peripheral surface 50a of the lens holding part 50 abuts against an outer peripheral surface of the first lens 31 without any gap, whereby the first lens 31 is positioned in the radial direction and disposed coaxially with the optical axis O. Furthermore, an annular surface 50b of the lens holding part 50 abuts against a flat bottom surface 31e of the first lens 31 facing the image side without any gap, whereby the first lens 31 is positioned in the optical axis direction. Furthermore, lenses 32 to 36 arranged on the image side of first lens 31 are held by lens barrel 22 so that their optical axes are aligned, and lens barrel 22 is arranged coaxially with second housing 24 and aligned with optical axis O, so that first lens 31 and lenses 32 to 36 arranged on the image side of first lens 31 are arranged coaxially or with an eccentricity of less than a predetermined amount.

[0040] In this embodiment, a vibration mechanism 60 that vibrates the first lens 31 is provided. The vibration mechanism 60 includes a transducer (vibration source) 61 that generates ultrasonic vibrations, and a vibrating body 62 that transmits the ultrasonic vibrations of the transducer 61 to the first lens 31. Such a vibration mechanism 60 is disposed radially inward from the first housing 23 and radially outward from the lens barrel 22. The vibrator (vibration source) 61 is formed in a circular plate shape, and is provided inside the housing body 23a of the first housing 23. The vibrator 61 is formed of, for example, a piezoelectric element.

[0041] The vibrating body 62 includes a donut-shaped disk-shaped attachment portion 62a, a main body portion 62b that extends from the attachment portion 62a toward the object side (upward in FIG. 1) and has an approximately cylindrical shape with bulges and constrictions with an S-shaped cross section, with the outer and inner diameters varying continuously in the axial direction (optical axis direction), and a ring-shaped joint portion 62c formed at the upper end portion of the main body portion 62b. The vibrator 61 is attached and fixed to the lower surface of the attachment portion 62a, and the upper surface of the joint portion 62c is joined to the lower surface (surface facing the image side) of the lens holding portion 50 with an adhesive.

[0042] In such vibration mechanism 60, the vibrator 61 ultrasonically vibrates, causing the vibrating body 62 to ultrasonically vibrate. When the vibrating body 62 vibrates, the first lens 31 ultrasonically vibrates via the lens holding part 50 because the vibrating body 62 is joined to the lens holding part 50, and thus foreign matter such as water droplets, muddy water, ice, snow, and frost on the lens surface 31a of the first lens 31 is removed.

[0043] The lens holding part 50 is fitted to the top plate part 23b of the first housing 23, but the thickness of the top plate part 23b is thinner than the thickness of the housing main body 23a, and the top plate part 23b functions as a damper, so that the vibration of the lens holding part 50 is not easily transmitted to the housing main body 23a. Therefore, the vibration is not easily transmitted to the second housing 24 fitted to the housing main body 23a, and as a result, the vibration is not easily transmitted to the lens barrel 22 fitted to the second housing 24, and the vibration is not easily transmitted to the lenses 32 to 36, so that the deterioration of the optical performance caused by the displacement of the lenses 32 to 36 due to the vibration can be suppressed.

[0044] In this embodiment, the second housing 24 is provided with a drive circuit board 305 for applying a drive signal to the vibrator (vibration source) 61, and a wiring 306 for connecting the vibrator 61 and the drive circuit board 305. The wiring 306 is formed by an FPC (Flexible Printed Circuit), but is not limited to this. Since the FPC is flexible, the wiring 306 is also flexible and can be bent relatively easily. A portion of the wiring 306 is fixed to the second housing 24 in the following manner. That is, first, a wiring hole 24f is formed in the inner flange portion 24a of the second housing 24. This wiring hole 24f is formed, for example, in an elliptical shape so that wiring 306 formed of an FPC can be passed through. Also, the inner flange portion 24a is formed to be thicker on the outer periphery side of the wiring hole 24f than on the inner periphery side. In this embodiment, one wiring hole 24f is formed in the inner flange portion 24a, but a plurality of wiring holes 24f may be formed.

[0045] A wire 306 is passed through the wiring hole 24f. One end of the wire 306 is connected to the vibrator 61, and the other end is connected to the drive circuit board 305. The middle of the wire 306 is arranged along the inner wall surface 24g and is adhesively fixed to the inner wall surface 24g with an adhesive. The wire 306 further extends from the fixed position where the wire 306 is adhesively fixed to the drive circuit board 305 side, and is connected to the drive circuit board 305.

[0046] In this embodiment, as shown in FIG. 1, lens unit 20 is composed of first housing 23, first lens 31 held in first housing 23, lens barrel 22, lenses 32-36 held in lens barrel 22, lens holding section 50, vibration mechanism 60, second housing 24, drive circuit board 305 provided in second housing 24, wiring 306, etc. The lens unit 20 and a package sensor (imaging element; image sensor) 304 provided inside the second housing 24 constitute a camera module 300 of the present embodiment.

[0047] Package sensor 304 is disposed inside second housing 24 facing filter 99, and is disposed at a position where it receives an image of an object formed by lens unit 20. Package sensor 304 also includes a CCD, CMOS, or the like, and converts the light that is collected and reaches it through lens unit 20 into an electrical signal. The converted electrical signal is converted into analog data or digital data, which is a component of image data captured by the camera.

[0048] In addition, this embodiment is provided with a stray light prevention section 351 that prevents transmitted light that has passed through the outer periphery of the first lens 31 and / or transmitted light that has passed between the lens barrel 22 and the first lens 31 from passing between the lens barrel 22 and the vibration mechanism 60 and entering the package sensor (imaging element) 304.

[0049] The stray light prevention unit 351 is configured such that the wiring hole 24f provided in the second housing 24 is disposed in a blind spot of a predetermined range rg of an image forming surface 304a on which light rays collected through the lens group are imaged. The image forming surface 304a coincides with the sensor surface which is the object side surface of the image sensor 304, and the wiring hole 24f is disposed in the blind spot of the predetermined range rg of the image forming surface 304a. The center of the imaging surface 304a is located on the optical axis O. The imaging surface 304a is formed, for example, in a rectangular shape, and the center of the imaging surface 304a is the intersection of a line segment connecting the centers of the opposing long sides of the rectangle and a line segment connecting the centers of the opposing short sides. The inside of a rectangle defined by a line segment spaced a predetermined distance from the center of the imaging surface 304a in the long side direction and a line segment spaced a predetermined distance in the short side direction is the predetermined range rg.

[0050] Stray light SL, which enters from the outer periphery of first lens 31 and passes between lens barrel 22 and vibration mechanism 60, is reflected, for example, at the outer periphery of the upper end of lens barrel 22 and travels toward second housing 24. No wiring hole 24f is formed in the portion of second housing 24 that this stray light SL reaches, but serves as a wall of inner flange portion 24a to prevent the passage of stray light SL. Wiring hole 24f is formed in inner flange portion 24a radially outward from the portion that this stray light SL reaches.

[0051] The stray light SL that reaches the arrival portion (the wall portion of the inner flange portion 24a) is reflected at the arrival portion, and is further reflected by the main body portion 62b of the vibrating body 62 of the vibration mechanism 60. This reflected stray light SL is further reflected by the inner circumferential surface of the wiring hole 24f and the wiring 306, but this reflected stray light SL does not enter a predetermined range rg of the sensor surface (imaging surface) 304a of the image sensor 304. In other words, no matter what angle the stray light SL passes through the wiring hole 24f of the second housing 24, the wiring hole 24f is positioned at a position where it does not enter a specified range rg of the sensor surface (imaging surface) 304a of the image sensor 304, that is, in the blind spot of the specified range rg of the imaging surface 304a of the image sensor 304.

[0052] According to this embodiment, the stray light prevention unit 351 is configured to place the wiring hole 24f provided in the second housing 24 in a blind spot of the predetermined range rg of the imaging surface 304a of the image sensor 304, so that transmitted light passing through the gap between the lens barrel 22 and the vibration mechanism 60 directly or after being reflected does not enter the predetermined range rg of the imaging surface 304a of the image sensor 304 even if it passes through the wiring hole 24f. In other words, it is possible to prevent transmitted light (stray light) SL from entering the predetermined range rg of the imaging surface 304a of the image sensor 304.

[0053] Moreover, since the lens holding part 50 is joined to the first housing 23, the lens holding part 50 can be reliably attached to a predetermined position. Moreover, since the vibration mechanism 60 is disposed radially inward from the first housing 23 and radially outward from the lens barrel 22, the vibration mechanism 60 can be protected by the first housing 23, and since the lenses 32 to 36 disposed on the image side of the first lens 31 are held by the lens barrel 22, the vibration mechanism 60 does not interfere with the lenses 32 to 36.

[0054] Furthermore, since the inner surface 50a of the lens holding portion 50 abuts against the outer surface of the first lens 31, and the annular surface 50b of the lens holding portion 50 abuts against the bottom surface 31e facing the image side of the first lens 31, the first lens 31 can be easily and accurately positioned in the radial and axial directions (optical axis direction).

[0055] Second Embodiment FIG. 3 is a schematic cross-sectional view showing a camera module according to a second embodiment of the present invention. This embodiment differs from the first embodiment in the configuration of the stray light prevention section, so this point will be explained below, and the same components as in the first embodiment will be given the same symbols and their explanations may be omitted.

[0056] As shown in FIG. 3, in this embodiment, the stray light prevention unit 352 is configured by providing an incidence prevention member in the second housing 24 to prevent transmitted light (stray light) that has passed through the outer periphery of the first lens 31 from entering a predetermined range rg of the imaging surface 304a of the image sensor 304. That is, an incidence prevention member 70 is provided in wiring hole 24f. Incident prevention member 70 is formed of a material such as resin that does not have light transmissivity. Incident prevention member 70 is formed in an arc plate shape or a rectangular plate shape, and is disposed along the inner circumferential surface of wiring hole 24f on the side closer to optical axis O. In addition, an upper end of incidence prevention member 70 abuts against protrusion 27 at the lower end of barrel 22, and a lower end extends downward from sensor surface (imaging surface) 304a of image sensor 304. Incidentally, the incidence prevention member 70 may be configured to be provided integrally as a part of the lens barrel 22, or may be configured to be provided integrally as a part of the second housing 24.

[0057] Stray light SL1 that has passed through the outer periphery of first lens 31 is reflected by the outer periphery of lens barrel 22, and is further reflected by the inner periphery of wiring hole 24f and heads toward image sensor 304, but is prevented from traveling radially inward by incidence prevention member 70. Stray light SL2 that has passed through the outer periphery of first lens 31 is reflected by wiring 306 and heads toward image sensor 304, but is prevented from traveling radially inward by incidence prevention member 70. Therefore, the stray light beams SL1 and SL2 do not enter the predetermined range rg of the imaging surface 304a of the image sensor 304.

[0058] According to this embodiment, the stray light prevention unit 352 is configured such that the second housing 24 is provided with an incidence prevention member 70 that prevents stray light (transmitted light) SL1, SL2 from entering a predetermined range rg of the imaging surface 304a of the image sensor 304. Therefore, even if the stray light (transmitted light) SL1, SL2 passes through the gap between the lens barrel 22 and the vibration mechanism 60, either directly or by reflection, the incidence prevention member 70 can prevent the stray light (transmitted light) SL1, SL2 from entering the predetermined range rg of the imaging surface 304a of the image sensor 304.

[0059] (Third embodiment) FIG. 4 is a schematic cross-sectional view showing a camera module according to a third embodiment of the present invention. This embodiment differs from the first embodiment in the configuration of the stray light prevention section, so this point will be explained below, and the same components as in the first embodiment will be given the same symbols and their explanations may be omitted.

[0060] As shown in FIG. 4, in this embodiment, stray light prevention section 353 is configured such that part of barrel 22 and part of vibration mechanism 60 overlap in the optical axis direction and are continuous in the circumferential direction. That is, first, a recess 22a having an arc-shaped cross section is formed along the circumferential direction on part of the outer circumferential surface of lens barrel 22. Also, part of main body 62b of vibration mechanism 60 forms bulging portion 62d that bulges radially inwardly into an arc-shaped cross section. The cross-sectional arc-shaped surface of bulging portion 62d facing recess 22a and the cross-sectional arc-shaped surface of recess 22a have approximately the same radius of curvature, and bulging portion 62d fits into recess 22a with a predetermined gap between them. As a result, a part of barrel 22 and a part of vibration mechanism 60 overlap in the optical axis direction and are continuous in the circumferential direction. Therefore, the stray light SL that has passed through the outer periphery of the first lens 31 is reflected by the main body 62b of the vibration mechanism 60, but since the bulging portion 62d enters the recess 22a with a predetermined gap, the stray light SL does not travel toward the image side from the bulging portion 62d. For this reason, the stray light SL does not enter a predetermined range rg of the imaging surface 304a of the image sensor 304.

[0061] FIG. 5 is a schematic cross-sectional view showing a camera module according to a first modified example of the third embodiment. The first modified example differs from the fourth embodiment in the configuration of the lens barrel 22, so this point will be explained below, and the same components as in the fourth embodiment will be given the same reference symbols and their explanations may be omitted.

[0062] In the third embodiment, recess 22a having an arc-shaped cross section is formed along the circumferential direction on part of the outer circumferential surface of barrel 22, but in the first modified example, the diameter of approximately the lower half on the image side (lower side in FIG. 8) in the optical axis direction of barrel 22 is shorter than the diameter of approximately the upper half on the object side (upper side in FIG. 8). In other words, barrel 22 has large diameter portion 22b in the upper half and small diameter portion 22c in the lower half, and large diameter portion 22b and small diameter portion 22c are connected by arc surface 22d having an arc-shaped cross section. The bulging portion 62d is located close to the arcuate surface 22d and the outer peripheral surface of the upper end of the small diameter portion 22c with a predetermined gap therebetween, and in this state the bulging portion 62d is located radially inward from the outer peripheral surface of the large diameter portion 22b. As a result, a part of the lens barrel 22 and a part of the vibration mechanism 60 overlap in the optical axis direction and are continuous in the circumferential direction.

[0063] Therefore, the stray light SL that has passed through the outer periphery of the first lens 31 is reflected by the main body 62b of the vibration mechanism 60, but since the bulge 62d is close to the arcuate surface 22d and the outer periphery of the upper end of the small diameter portion 22c with a predetermined gap therebetween, the stray light SL does not travel toward the image side from the bulge 62d. For this reason, the stray light SL does not enter the predetermined range rg of the imaging surface 304a of the image sensor 304.

[0064] FIG. 6 is a schematic cross-sectional view showing a camera module according to a second modified example of the third embodiment. The second modified example differs from the third embodiment in the configuration of the lens barrel 22, so this point will be explained below, and the same components as in the third embodiment will be given the same reference symbols and their explanations may be omitted.

[0065] In the third embodiment, a recess 22a having an arc-shaped cross section is formed along the circumferential direction on part of the outer circumferential surface of the lens barrel 22, but in the second modified example, the diameter of the upper part on the image side (upper side in FIG. 6) in the optical axis direction of the lens barrel 22 is shorter than the diameter of the lower part on the object side (lower side in FIG. 6). In other words, the lens barrel 22 has an upper small diameter part 22e and a lower large diameter part 22f, and the small diameter part 22e and the large diameter part 22f are connected by an arc surface 22g having an arc-shaped cross section. The bulging portion 62d is located close to the arcuate surface 22g and the outer peripheral surface of the lower end of the small diameter portion 22e with a predetermined gap therebetween, and in this state, the bulging portion 62d is located radially inward from the outer peripheral surface of the large diameter portion 22f. As a result, a part of the lens barrel 22 and a part of the vibration mechanism 60 overlap in the optical axis direction and are continuous in the circumferential direction.

[0066] Therefore, the stray light SL that has passed through the outer periphery of the first lens 31 is reflected by the main body 62b of the vibration mechanism 60, but since the bulge 62d is close to the arcuate surface 22g and the outer periphery of the lower end of the small diameter portion 22e with a predetermined gap therebetween, the stray light SL does not travel toward the image side from the bulge 62d. For this reason, the stray light SL does not enter the predetermined range rg of the imaging surface 304a of the image sensor 304.

[0067] According to this embodiment, the stray light prevention section 353 is configured such that a part of the lens barrel 22 (recess 22a, arcuate surfaces 22d, 22g) and a part of the vibration mechanism 60 (bulge 62d) overlap in the optical axis direction and are continuous in the circumferential direction, so that the stray light (transmitted light) SL does not advance to the image side beyond this overlapping part. Therefore, it is possible to prevent the stray light (transmitted light) SL from entering a predetermined range rg of the imaging surface 304a of the image sensor 304.

[0068] (Fourth embodiment) FIG. 7 is a schematic cross-sectional view showing a camera module according to the fourth embodiment of the present invention. This embodiment differs from the first embodiment in the configuration of the stray light prevention section, so this point will be explained below, and the same components as in the first embodiment will be given the same symbols and their explanations may be omitted.

[0069] As shown in FIG. 7, in this embodiment, the stray light prevention section 354 is configured such that the wiring hole 24f is provided radially outward from the vibration mechanism 60. That is, the wiring hole 24f is provided on the outer periphery of the inner flange portion 24a of the second housing 24, radially outward from the vibration mechanism 60. One end of the wiring 306 is connected to the transducer 61, the wiring 306 extends radially outward from the connected position and is passed through the wiring hole 24f, and the other end is connected to the drive circuit board 305.

[0070] Therefore, stray light SL that has passed through the outer periphery of first lens 31 is reflected by the outer periphery of barrel 22 and reaches inner flange portion 24a of second housing 24, but does not pass through wiring hole 24f because wiring hole 24f is provided radially outward from vibration mechanism 60. For this reason, stray light SL does not enter a predetermined range rg of imaging surface 304a of image sensor 304.

[0071] According to this embodiment, since the stray light prevention unit 354 is configured such that the wiring hole 24f is provided radially outward from the vibration mechanism 60, the transmitted light (stray light) SL that passes through the gap between the lens barrel 22 and the vibration mechanism 60 directly or after being reflected does not pass through the wiring hole 24f. Therefore, it is possible to prevent the transmitted light (stray light) SL from entering a predetermined range rg of the imaging surface 304a of the image sensor 304.

[0072] FIG. 8 shows a vehicle 240 as a moving body equipped with an in-vehicle system (imaging system) including an imaging device 250 including the camera module 300 shown in FIG. 1, FIG. 3, FIG. 4, FIG. 5, FIG. 6 or FIG. 7. As shown in the figure, the imaging device 250 can be mounted on the vehicle 240, and FIG. 8 shows 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 places 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 when the vehicle 240 is traveling. The second imaging device 250b that monitors the front may be disposed near the room mirror (inner rearview mirror) in the vehicle interior of 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 driving situation of the driver. The fourth imaging device 250d may be installed at the rear of the vehicle 240 for rear monitoring of the vehicle 240. The imaging devices 250a and 250b may be called front cameras. The third imaging device 250c may be called an in-camera. The fourth imaging device 250d may be called a rear camera. The imaging device 250 is not limited to these, and may include imaging devices installed at 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.

[0073] An image signal of an image captured by the imaging device 250 may be output to an information processing device 242 and / or a display 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 an image signal acquired by the imaging device 250, recognizes the image, and assists the driver in driving. The information processing device 242 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 243 displays an image processed and output by the information processing device 242, but can also receive an image signal directly from the imaging device 250. The display device 243 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 243 can display to the driver (can output information to passengers) an image signal output from an imaging device 250 that captures an image from a position that is difficult for the driver to view, such as a rear camera.

[0074] Fig. 9 shows the configuration of an imaging device constituting the in-vehicle system shown in Fig. 8. As shown in the figure, an imaging device 250 according to the embodiment includes a control unit 252, a storage unit 254, and a camera module 300.

[0075] The control unit 252 controls the camera module 300 and processes an electrical signal output from the image sensor 304 of the camera module 300. The control unit 252 may be configured as a processor, for example. The control unit 252 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). The application-specific IC may be an application specific integrated circuit (ASIC). The processor may include a programmable logic device, which is also called a programmable logic device (PLD). A PLD is a field-programmable gate array (FPGA). The control unit 252 may be either a System-on-a-Chip (SoC) or a System In a Package (SiP) in which one or more processors work together.

[0076] The storage unit 254 stores various information or parameters related to the operation of the imaging device 250. The storage unit 254 may be composed of, 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.

[0077] 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 called a captured image.

[0078] The image sensor 304 may be configured, for example, as a complementary metal oxide semiconductor (CMOS) image sensor or a charge coupled device (CCD). 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.

[0079] The imaging data may be read by the camera module 300 for all pixels and taken into the control unit 252 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 300 for some pixels and taken into the control unit 252 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 252. The camera module 300 may obtain the predetermined capture range from the control unit 252. The imaging element 304 may capture an image of a predetermined capture range of a subject image formed through the lens unit 20.

[0080] The present invention is not limited to the above-mentioned embodiment, and can be modified in various ways without departing from the scope of the present invention. For example, the shapes of the lens, the housing, the lens barrel, etc. are not limited to the above-mentioned embodiment. Furthermore, the above-mentioned embodiments may be combined in part or in whole, or a part of the configuration may be omitted from one of the above-mentioned embodiments, without departing from the scope of the present invention. [Explanation of symbols]

[0081] 20 Lens unit 22 Telescope tube 23 1st cabinet 24 2nd cabinet 24f Wiring hole 31 First lens 60 Vibration mechanism 61 Piezoelectric element (vibrator, vibration source) 62 Vibration Body 70 Incidence prevention member 240 Vehicles (mobile) 242 Information processing equipment (processing equipment) 243 Display device 250 Imaging Device 252 Control section 300 Camera Module 304 Image sensor 305 Drive circuit board 306 Wiring 351,352,353,354 Stray light prevention section

Claims

1. A lens unit including a lens group in which a plurality of lenses are arranged along the optical axes of the lenses, and a vibration mechanism having a vibration source that vibrates a first lens that is located closest to an object among the plurality of lenses, a first housing in which the first lens is provided, a lens barrel in which a lens located closer to the image side than the first lens is provided and which is provided radially inward from the first housing, a second housing which is disposed closer to the image side than the first housing and which fits into the first housing, the vibration mechanism provided between the first housing and the lens barrel, wiring for applying a drive signal to the vibration source, and a wiring hole provided in the second housing and through which the wiring passes; A lens unit characterized in that it is provided with a stray light prevention section that prevents transmitted light that has passed through the outer periphery of the first lens and / or transmitted light that has passed between the lens barrel and the first lens from passing between the lens barrel and the vibration mechanism and entering a predetermined range of an image forming plane where light rays focused through the lens group are imaged.

2. 2. The lens unit according to claim 1, wherein the second housing is provided with a drive circuit board for applying a drive signal to the vibration source via the wiring, and the drive circuit board and the vibration source are connected by the wiring.

3. 2. The lens unit according to claim 1, wherein the stray light prevention portion is configured such that the wiring hole is disposed in a blind spot of a predetermined range on the image forming surface.

4. The lens unit according to claim 1 , wherein the stray light prevention section is configured by providing an incidence prevention member in the second housing that prevents the transmitted light from entering a predetermined range of the image plane.

5. 2. The lens unit according to claim 1, wherein the stray light prevention portion is configured such that a part of the lens barrel and a part of the vibration mechanism overlap in the optical axis direction and are continuous in the circumferential direction.

6. 2. The lens unit according to claim 1, wherein the stray light prevention portion is configured such that the wiring hole is provided radially outward from the vibration mechanism.

7. 7. A camera module comprising: a lens unit according to claim 1; and an image sensor that converts light focused through the lens group of the lens unit into an electrical signal.

8. an imaging device comprising: the camera module according to claim 7; and a control unit that controls the camera module and processes an electrical signal output from an imaging element of the camera module; a processing device that processes an image signal acquired by the imaging device; a display device that displays an image that has been processed and output by the processing device; An imaging system comprising:

9. 9. A vehicle equipped with the imaging system according to claim 8, wherein information is output to a passenger by the display device.

Images