Lens unit, camera module, in-vehicle system, and moving body

Abstract

To provide a lens unit, a camera module, an in-vehicle system, and a moving body, which prevent occurrence of an airtightness failure of a sealing material for sealing between a lens barrel and a lens so as to cut off an intrusion passage of water vapor from an image side into the lens barrel.SOLUTION: In a lens unit 11, a sealing material 70 for sealing so as to cut off a gas flow passage from an image side toward an object side between an outer peripheral surface 18b of a lens 18 loosely fitted in a lens barrel 12 among a plurality of lenses and an inner peripheral surface 12b of a lens barrel 12 is provided. Roughening treatment is performed on a portion 12c of the inner peripheral surface 12b of the lens barrel 12 in contact with the sealing material 70. A radial dimension X of a gap g between the outer peripheral surface 18b of the loosely fitted lens 18 and the inner peripheral surface 12b of the lens barrel 12, which form the gas flow passage, is set to 0.3% to 1.0% of an outer diameter R of the loosely fitted lens 18.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention particularly relates to a lens unit constituting an on-board camera mounted on a vehicle such as an automobile, a camera module, an on-board system, and a moving body equipped with the on-board 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] Furthermore, particularly in lens units for vehicle-mounted cameras, when at least a portion of the lens unit is installed outside the vehicle, for waterproofing and dustproofing, as in lens unit 500 shown in FIG. 6, lens group L consisting of multiple lenses arranged along optical axis O is incorporated and housed within inner housing space S of lens barrel 120, and a sealing member, for example an O-ring 140, is interposed between first lens 100, which is positioned closest to the object in lens group L, and lens barrel 120 to prevent water and dust from entering lens group L inside lens barrel 120. In this case, a stepped reduced diameter portion 100b, the diameter of which is reduced in the image side portion of the lens 100, is provided on the outer peripheral side surface 100a of the first lens 100, and an O-ring 140 is attached to this reduced diameter portion 100b. The O-ring 140 is compressed, for example in the radial direction, between the outer peripheral side surface 100a of the first lens 100 and the inner peripheral surface 120a of the lens barrel 120, thereby sealing the object side end of the lens barrel 120.

[0004] Furthermore, if the lens barrel 120 is made of resin, it generally has a crimped portion 123 at its object side end (the upper end in FIG. 6) as shown in FIG. 6, for example. In this case, with the lens group L incorporated and housed and held in the inner housing space S of the lens barrel 120, the crimped portion 123 is crimped radially inward, thereby fixing the first lens 100 to the object side end of the lens barrel 120 by this crimped portion 123. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2013-231993 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, even if waterproofing is implemented using O-ring 140 as described above, moisture (water vapor) can enter lens unit 500 through various routes. Therefore, when the difference between the outside air temperature and the temperature inside lens unit 500 becomes large, the water vapor inside lens unit 500 condenses and condensation occurs on the lens surface. In particular, condensation is likely to occur on back surface 100c of first lens 100 in inter-lens space S1 between first lens 100 and adjacent second lens 101, which is most affected by the temperature difference with the outside.

[0007] Factors that cause a large difference between the outside air temperature and the temperature inside the lens unit 500 include the temperature inside the lens unit 500 rising in winter when the outside air is cold; specifically, for example, the temperature inside the lens unit 500 rising due to heat transmitted from the image sensor (image pickup element) 520, which is always powered and receives light focused through the lens unit 500 and converts it into an electrical signal; or the first lens 100 being cooled when the surface 100d of the first lens 100, which is exposed to the outside, is exposed to the outside air or rain or is splashed by water from puddles on the road, while the temperature inside the lens unit 500 is high due to heat from the image sensor 520 or the surrounding environment (for example, a vehicle engine).

[0008] In addition, possible paths that allow water vapor to enter lens unit 500 include, for example, a path that passes from the gap between crimped portion 123 of lens barrel 120 and first lens 100 through part of the periphery of O-ring 140 and the gap between first lens 100 and lens barrel 120 and / or second lens 101 to inter-lens space S1, or a path that passes directly through the moisture-permeable resin of lens barrel 120, or a path that passes sequentially through the moisture-permeable resin that forms lens barrel 120 and the lenses. However, the most concerning possibility is that heat generated by image sensor 520 will cause moisture in substrate 522 supporting sensor 520 to evaporate, and the water vapor will enter lens unit 500 from the image side and ultimately enter inter-lens space S1.

[0009] In any case, if water vapor gradually enters the lens unit 500 through such a route, and a temperature difference occurs between the outside air and the inside of the lens unit 500 due to the factors described above, condensation will occur in the inter-lens space S1, particularly on the back surface 100c of the first lens 100, causing the captured image to become blurred and making it impossible to obtain the desired resolution (deteriorating visibility). Therefore, it is necessary to further ensure the airtightness of the lens unit 500 and suppress the intrusion of water vapor into the inter-lens space S1.

[0010] For this reason, for example, in order to seal so as to block the intrusion path of water vapor from the image side where the image sensor 520 is located toward the space S1 between the first lens 100 and the second lens 101, it has been conventional to fill a sealant such as an adhesive into the gap between the lens barrel 120 and any optical element (lens, intermediate ring, diaphragm, etc.) located on the image side of the space S1 between the lenses. For example, in Fig. 6, as an example, a sealing adhesive 550 is applied on the outer periphery of the lens 102 located closest to the image side so as to be interposed between the lens 102 and the lens barrel 120, thereby sealing so as to block the intrusion path 555 of water vapor from the image side.

[0011] Here, when lens 102 is a resin lens having a shape that is easily deformed such as a meniscus lens, it is generally necessary to avoid press-fitting lens 102 into the inner surface of lens barrel 120 in order to prevent deformation of lens 102. Therefore, in the example shown in Fig. 6, lens 102 is loosely fitted into lens barrel 120, that is, fitted with a backlash that forms a gap g between the inner surface of lens barrel 120 and the outer circumferential surface of lens 102. The radial and axial positions of lens 102 are determined by fitting lens 102 into lens 103 adjacent to it on the object side.

[0012] Specifically, as shown in FIG. 7, the lens 102 to be positioned closest to the image side is first inserted into the lens barrel 120 and positioned loosely at the bottom of the inner storage space S of the lens barrel 120. After that, adhesive 550 made of, for example, ultraviolet curing resin for sealing is applied to the outer periphery of the lens 102, and then the lens 103 is inserted into the lens barrel 120 from the object side and press-fitted and placed on the lens 102. At this time, the convex portion 103a formed on the surface of the lens 103 facing the image side is fitted into the concave portion 102a formed on the surface of the lens 102 facing the object side, and the lens 102 is positioned in the radial and axial directions based on the lens 103 that has been positioned in the radial and axial directions by press-fitting with respect to the lens barrel 120. After that, ultraviolet light is irradiated to harden the adhesive 550, and the other lenses 104 and the like on the object side are inserted into the lens barrel 120 one by one.

[0013] However, in this assembly form in which lens 102 to which adhesive 550 is to be applied is loosely fitted into lens barrel 120 and engaged with lens 103 on the object side, when lens 103 is engaged with lens 102, lens 102, which is loosely fitted with a gap g between it and lens barrel 120, moves radially, causing adhesive 550 sealing gap g to flow and destroying the sealing state, which may open up a path 555 for water vapor to enter from the image side.

[0014] The sealing state by the adhesive 550 may be impaired not only by such radial movement of the lens 102 but also by the expansion and contraction of the lens 102 due to the annealing process after the assembly of the lens unit 500 is completed. That is, the adhesive strength of the adhesive 550 may decrease due to the expansion of the lens 102 during processing in the annealing process and the contraction of the lens 102 after being removed from the annealing process, and the adhesive 550 may peel off from the lens barrel 120 side or the lens 102 side, and the sealing state of the intrusion path 555 may be impaired. In particular, the peeling off of the adhesive 550 from the lens barrel 120 side may directly lead to the opening of the intrusion path 555, and is also due to the fact that the adhesive 550 is merely attached to the inner surface of the lens barrel 120 from the side, i.e., the adhesive retention force of the lens barrel 120 is weak.

[0015] In addition, the gap g between the lens barrel 120 and the lens 102 due to the loose fit of the lens 102 ultimately contributes to the formation of the intrusion path 555 for water vapor from the image side mentioned above, and therefore requires improvement.

[0016] The present invention has been made in consideration of the above-mentioned circumstances, and aims to provide a lens unit, a camera module, an in-vehicle system, and a mobile body that prevent airtightness problems in the sealing material that seals between the lens barrel and the lens so as to block the path of water vapor entering the lens barrel from the image side. [Means for solving the problem]

[0017] In order to solve the above problems, the present invention provides a lens unit including a lens group including a plurality of lenses arranged along an optical axis, and a lens barrel having an inner storage space for storing and holding the lens group, a sealant is provided between an outer peripheral surface of a lens of the plurality of lenses that is loosely fitted in the lens barrel and an inner peripheral surface of the lens barrel so as to block a gas flow path from an image side to an object side; a portion of an inner peripheral surface of the lens barrel that comes into contact with the sealing material is roughened; a radial dimension of a gap between an outer peripheral surface of the loosely fitted lens and an inner peripheral surface of the lens barrel, which forms the gas flow passage, is set to 0.3% to 1.0% of an outer diameter of the loosely fitted lens; It is characterized by:

[0018] In the present invention, a sealant is provided to seal the gap between the outer peripheral surface of the loose-fit lens (lens loosely fitted in the lens barrel; the same applies below) and the inner peripheral surface of the lens barrel, which may be a path (gas flow path) for water vapor to enter the lens barrel from the image side, and the inner peripheral surface of the lens barrel is roughened, so that the contact area between the inner peripheral surface of the lens barrel and the sealant can be increased, and the roughening increases the locking force of the sealant by the lens barrel, thereby strengthening the sealant retention force, thereby realizing a highly reliable sealing state in the gas flow path. Therefore, even if the loose-fit lens moves in the radial direction when, for example, another lens on the object side is fitted to the loose-fit lens to position the loose-fit lens in the radial and axial directions, the sealing state of the sealant can be prevented from being damaged, and the sealant can also be prevented from peeling off from the lens barrel side due to the expansion and contraction movement of the loose-fit lens due to the annealing process after the lens unit is assembled.

[0019] In addition, in the above-mentioned configuration of the present invention, the radial dimension of the gap between the outer peripheral surface of the loose-fit lens and the inner peripheral surface of the lens barrel is set to 0.3% to 1.0% of the outer diameter of the loose-fit lens, so that the gap that can be a path for water vapor to enter the lens barrel from the image side can be kept as small as possible, while the lens press-fitting that can cause lens deformation can be avoided (lens can be loosely fitted). In addition, if the radial dimension of the gap between the loose-fit lens and the lens barrel is set to 0.3% to 1.0% of the outer diameter of the loose-fit lens, the loose-fit lens can be easily assembled to the lens barrel, and the radial movement amount of the loose-fit lens can be regulated when, for example, another lens on the object side is fitted to the loose-fit lens to position the loose-fit lens in the radial and axial directions, and therefore, the sealing state of the sealant can be prevented from being damaged by such movement. In addition, such a gap dimension setting range not only effectively controls the amount of expansion and deformation of the loose-fit lens due to the annealing process after the lens unit is assembled, but also allows the radial inward protrusion of the lens barrel material due to the roughening of the lens barrel (particularly the blasting process) to contribute greatly to the setting of this dimension range. If the radial dimension of the gap between the outer peripheral surface of the loose-fit lens and the inner peripheral surface of the lens barrel is less than 0.3% of the outer diameter of the loose-fit lens, it becomes difficult to achieve good loose fitting and assembly of the lens, and if it exceeds 1.0%, it becomes difficult to maintain a sealed state of the gas flow path even by roughening.

[0020] In this way, the above-mentioned configuration of the present invention restricts the radial movement and deformation of the lens by defining the radial dimension of the gap between the outer peripheral surface of the loose-fit lens and the inner peripheral surface of the lens barrel within a predetermined range, and prevents the sealing state of the sealant from being damaged when the lens moves radially and deforms by roughening the lens barrel. As a result, the reliability of the sealing state of the sealant can be improved and the sealant can be prevented from having poor airtightness.

[0021] In the above configuration, "loose fit" refers to a state in which the lens barrel is fitted to the inner peripheral surface thereof with a certain amount of play (gap) in the radial direction. Furthermore, examples of the "sealing material" include materials that block the flow of gas (water vapor) toward the object side within the inner storage space, such as adhesive media, water vapor adsorbents (water absorbents), and airtight materials. When an adhesive is used as the sealing material, such adhesives are particularly preferred, particularly olefin-based adhesives with low moisture permeability (for example, 60 g / m 2 It is preferable to use an adhesive (e.g., a UV-curable adhesive) with a moisture permeability of 24 hours or less, and it is particularly preferable to use a colored adhesive other than transparent (e.g., white, black, milky white close to gray, etc.). This is because a transparent adhesive may reflect light and cause a ghost phenomenon. In addition, it is preferable that the thickness of the adhesive layer of the sealing material is 0.3 mm or more,

[0022] In the above configuration, the loose-fitting lens is preferably the lens that is located closest to the image side of the lens group. In this way, among the paths that allow the intrusion of water vapor into the lens unit, if a sealant is provided between the lens barrel and the lens and the above-mentioned gap dimension setting and surface roughening treatment are performed at the image side end where the intrusion of water vapor into the lens unit is most likely, the water vapor moving toward the object side in the inner storage space of the lens barrel can be cut off at its source, so that the entire inner storage space of the lens barrel can be kept in a low humidity state, and an excellent lens anti-fogging effect can be achieved for all the lenses that make up the lens group.

[0023] The present invention also provides a camera module having the lens unit described above, an in-vehicle system having the camera module, and a moving body equipped with the in-vehicle system. The camera module, the in-vehicle system, and the moving body can also provide the same effects as those of 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

[0024] According to the present invention, it is possible to prevent airtight defects in the sealant that seals between the lens barrel and the lens so as to block the intrusion path of water vapor from the image side into the lens barrel. [Brief description of the drawings]

[0025] [Figure 1] 1 is a schematic cross-sectional view of a lens unit according to an embodiment of the present invention. [Diagram 2] FIG. 2 is an enlarged cross-sectional view of a main part of FIG. [Diagram 3] 2 is a schematic cross-sectional view of a camera module having the lens unit of FIG. 1. [Figure 4] 1 is a schematic diagram of a vehicle as a moving body on which an imaging system (on-vehicle system) including a camera module according to an embodiment of the present invention is mounted. [Diagram 5] 5 is a block diagram showing a configuration of an imaging device that constitutes the imaging system of FIG. 4. [Figure 6] FIG. 1 is a schematic cross-sectional view showing an example of a conventional lens unit. [Figure 7] 7 is a cross-sectional view showing a state in which lenses are partially assembled in a lens barrel in the lens unit of FIG. 6. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. This embodiment can realize a highly reliable system, particularly in a sensing system, and contributes to the development of resilient infrastructure, and targets "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." The lens unit of this embodiment described below is particularly intended for use in a camera module such as an in-vehicle camera, and is fixedly installed on the outer surface of a vehicle, with wiring drawn into the vehicle and connected to a display or other devices. In addition, hatching is omitted for the lenses in all figures, including the above-mentioned Figures 6 and 7.

[0027] 1 shows a lens unit 11 according to one embodiment of the present invention. As shown in the figure, the lens unit 11 of this embodiment includes a cylindrical lens barrel 12 made of, for example, resin (but may be made of metal), a plurality of lenses arranged in an inner storage space S of the lens barrel 12, for example, six lenses consisting of, from the object side, a first lens 13, a second lens 14, a third lens 15, a fourth lens 16, a fifth lens 17, and a sixth lens 18, and two aperture members 22a and 22b. In this case, the first lens 13 has a convex surface 13d on its object side and a concave surface 13e in the center of its image side surface, and the second lens 14 adjacent to the first lens 13 on its image side has a concave surface 14b in the center of its object side surface, and therefore, in the assembled state shown in Fig. 1 where the first and second lenses 13, 14 are joined together at their radially outer seating surfaces 13a, 14a, an interlens space S1 is formed within the lens effective diameter between the first lens 13 and the second lens 14. The third lens 15 is held by an inner holding part of a cylindrical resin intermediate spacer (intermediate ring) 30 interposed between the second lens 14 and the fourth lens 16, and this inner holding part holds the third lens 15 from the image side by a step 30a formed on the inner peripheral surface of the intermediate spacer 30. In addition, the intermediate spacer 30 has a crimping portion 30b at the upper part on its inner diameter side, and this crimping portion 30b is thermally crimped radially inward so as to press the image-side step surface 15a of the third lens 15 against the step portion 30a of the intermediate spacer 30 in the optical axis direction.

[0028] The fourth lens 16 and the fifth lens 17 are bonded together to form a composite lens 29. The sixth lens 18, which is located closest to the image side, is a meniscus lens that is easily deformed in an environment with rapid temperature changes, and is therefore loosely fitted with respect to the inner surface of the lens barrel 12 with a predetermined gap g (hereinafter, the sixth lens 18 will be referred to as the loose-fit lens 18). Therefore, in order to position the loose-fit lens 18 in the radial and axial directions, the loose-fit lens 18 is fitted with the fifth lens 17, which is adjacent to the lens 18 on the object side and press-fitted into the lens barrel 12. Specifically, the fifth lens 17 has an annular convex portion 17a formed on its image side surface fitted into a concave portion 18a on the object side surface of the loose-fit lens 18, thereby centering the lenses 16, 17, and 18 with each other.

[0029] In this embodiment, aperture members 22a, 22b are respectively interposed between the second lens 14 and the intermediate spacer 30, and between the intermediate spacer 30 and the fourth lens 16. These aperture members 22a, 22b are either an "aperture diaphragm" that limits the amount of transmitted light and determines the F-number, which is an index of brightness, or a "light blocking diaphragm" that blocks light rays that cause ghosts and light rays that cause aberrations. An in-vehicle camera equipped with such a lens unit 11 includes the lens unit 11, a substrate having an image sensor (not shown), and an installation member (not shown) for installing the substrate on a vehicle such as an automobile.

[0030] The lenses 13, 14, 15, 16, 17, and 18 are assembled and held in the inner storage space S of the lens barrel 12, and are stacked and arranged with their optical axes aligned, and the lenses 13, 14, 15, 16, 17, and 18 are arranged along one optical axis O to form a group of lenses L used for imaging. In this case, the first lens 13, which is positioned closest to the object side of the lens group L, is a spherical glass lens, and the third lens 15 held by the intermediate spacer 30 is also a spherical glass lens, and the other lenses 14, 16, 17, and 18 are resin lenses, but are not limited to this. In addition, the surfaces of these lenses 13, 14, 15, 16, 17, and 18 (the surfaces on the object side and / or the surfaces on the image side) are provided with an anti-reflection film, a hydrophilic film, a water-repellent film, or the like, as necessary. The lenses 13, 14, 15, 16, 17, and 18 of the lens group described above, the intermediate spacer (intermediate ring) 30, and the apertures 22a and 22b are all optical elements that are incorporated within the inner storage space S of the barrel 12 and contribute to the optical characteristics of the lens unit 11.

[0031] In this embodiment, an O-ring 26 serving as a seal member is interposed between the first lens 13, which is located closest to the object side, and the lens barrel 12 to prevent water and dust from entering the lens group L inside the lens barrel 12. In this case, a stepped reduced diameter portion 13c having a smaller diameter at the image side portion of the lens 13 is provided on the outer circumferential side surface 13b of the first lens 13, and an O-ring 26 is attached to this reduced diameter portion 13c, and the O-ring 26 is compressed in the radial direction between the outer circumferential side surface 13b of the first lens 13 and the inner circumferential surface of the lens barrel 12, thereby sealing the object side end of the lens barrel 12.

[0032] Furthermore, with lens group L assembled and housed in inner housing space S of lens barrel 12, crimping portion 23 at the object side end (upper end in FIG. 1) is crimped radially inward, thereby fixing first lens 13, which is positioned closest to the object side of lens group L, to the object side end of lens barrel 12 by crimping portion 23. Note that the fixing of first lens 13 is not limited to crimping portion 23, and may be performed by a fixing cap that is attached to the object side end of lens barrel 12 after lenses 13, 14, 15, 16, 17, and 18 are housed in lens barrel 12.

[0033] Further, an inner flange portion 24 having an opening with a diameter smaller than that of the loose-fit lens 18 is provided at the end (the lower end in FIG. 1) of the lens barrel 12 on the image side. The lenses 13, 14, 15, 16, 17, and 18 constituting the lens group L within the lens barrel 12, the intermediate spacer 30, and the diaphragm members 22a and 22b are held and fixed in the optical axis direction by this inner flange portion 24 and the crimped portion 23.

[0034] In addition, in the lens unit 11 of this embodiment, a sealant that seals so as to block the gas flow path toward the inter-lens space S1 is filled in the gap between the outer periphery of the optical element located on the image side of the inter-lens space S1 and the inner periphery of the lens barrel 12. In particular, in this embodiment, an adhesive 70 is applied as a sealant between the lens barrel 12 and the loose-fit lens 18, which is loosely fitted into the lens barrel 12 at the closest to the image side and therefore is likely to form an initial intrusion path (gas flow path) for water vapor from the image side into the lens barrel 12. In this case, the adhesive 70 is applied on the outer periphery of the loose-fit lens 18 so as to be interposed between the loose-fit lens 18 and the lens barrel 12. Specifically, as clearly shown in the enlarged view in Figure 2, adhesive 70 is applied and filled onto the annular step recess 18c (particularly, in this embodiment, formed around the entire circumference of the loose-fit lens 18) on the outer peripheral edge of the object-side surface of the loose-fit lens 18 so as to adhere to the inner peripheral surface 12c of the lens barrel 12, thereby sealing off the gas flow path from the image side to the object side between the outer peripheral surface 18b of the loose-fit lens 18 and the inner peripheral surface 12b of the lens barrel 12.

[0035] In this configuration in which the loose-fit lens 18 is provided with the adhesive 70, the lenses are assembled by first inserting the loose-fit lens 18 that is to be positioned closest to the image side into the lens barrel 12 and positioning it loosely at the bottom of the inner storage space S of the lens barrel 12. Then, adhesive 70 made of, for example, ultraviolet curing resin is applied to the outer periphery of the loose-fit lens 18. Next, the bonded lens 29 is inserted into the lens barrel 12 from the object side, and the fifth lens 17 of the bonded lens 29 is press-fitted into the lens barrel 12 and fitted and placed on the loose-fit lens 18. Then, ultraviolet light is irradiated to harden the adhesive 70, and the other lenses 15, 14, and 13 on the object side are inserted into the lens barrel 12 one by one.

[0036] In this embodiment, in order to increase the holding power of the adhesive 70 by the lens barrel 12, a portion 12c on the inner peripheral surface 12b of the lens barrel 12 that comes into contact with the adhesive 70 is roughened. In particular, in this embodiment, the portion 12c on the inner peripheral surface 12b of the lens barrel 12 is roughened by a blasting process. In this embodiment, the radial dimension X of the gap g between the outer peripheral surface 18b of the loose-fit lens 18 that forms the gas flow passage and the inner peripheral surface 12b of the lens barrel 12 is set to 0.3% to 1.0% of the outer diameter R of the loose-fit lens 18.

[0037] 3 is a schematic cross-sectional view of a camera module 300 of this embodiment having the lens unit 11 configured as described above. As shown in the figure, this camera module 300 is configured to include the lens unit 11 of FIG. 1 with a filter 99 attached to the image side end.

[0038] The camera module 300 includes an upper case (camera case) 301, which is an exterior component, and a mount (base) 302 that holds the lens unit 11. The camera module 300 also includes a seal member 303 and a package sensor (imaging element; image sensor) 304.

[0039] Upper case 301 is a member that engages with flange portion 25 that is provided like a brim on outer circumferential surface 12a of lens barrel 12, and that exposes the object side end of lens unit 11 and covers the other portions. Mount 302 is disposed inside upper case 301, and has female threads 302a that screw into male threads 11a of lens unit 11. Seal member 303 is a member that is interposed between the inner surface of upper case 301 and outer circumferential surface 12a of lens barrel 12 of lens unit 11, and is a member that maintains airtightness inside upper case 301.

[0040] Package sensor 304 is disposed inside mount 302, and is disposed at a position where it receives an image of an object formed by lens unit 11. Package sensor 304 has a transparent cover on the outside and is equipped with a CCD, CMOS, etc. inside, and converts light that is collected through lens unit 11 and reaches it 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.

[0041] As described above, according to this embodiment, adhesive 70 is provided to seal gap g between the outer surface 18b of the loose-fit lens 18 and the inner surface 12b of the lens barrel 12, which can serve as a path (gas flow path) for water vapor to enter the lens barrel from the image side. Since portion 12c of inner surface 12b of lens barrel 12 that comes into contact with adhesive 70 is roughened, the contact area between the inner surface of lens barrel 12 and adhesive 70 can be increased, and the roughening increases the retaining force of adhesive 70 by lens barrel 12, thereby strengthening the adhesive retention force, thereby achieving a highly reliable sealing state in the gas flow path. Therefore, even if the loose-fit lens 18 moves radially when, for example, fitting the fifth lens 17 to the loose-fit lens 18 to position the loose-fit lens 18 radially and axially, the sealing state of the adhesive 70 can be prevented from being damaged, and peeling of the adhesive 70 from the lens barrel 12 side due to the expansion and contraction movement of the loose-fit lens 18 due to the annealing process after assembly of the lens unit described above can also be prevented.

[0042] In addition, in the above-mentioned configuration of the present embodiment, the radial dimension X of the gap g between the outer peripheral surface 18b of the loose-fit lens 18 and the inner peripheral surface 12b of the lens barrel 12 is set to 0.3% to 1.0% of the outer diameter R of the loose-fit lens 18, so that the gap g that can be a path for water vapor to enter the lens barrel from the image side can be kept as small as possible, while the press-fitting of the loose-fit lens 18 that can cause lens deformation can be avoided (loose fitting of the lens 18 is possible). In addition, if the radial dimension of the gap g between the loose-fit lens 18 and the lens barrel 12 is set to 0.3% to 1.0% of the outer diameter R of the loose-fit lens 18, the loose-fit lens 18 can be easily assembled to the lens barrel 12, and the radial movement amount of the loose-fit lens 18 when, for example, the fifth lens 17 is fitted to the loose-fit lens 18 to perform radial and axial positioning of the loose-fit lens 18 can also be regulated, and therefore, the adhesive 70 sealing state can be prevented from being damaged by such movement. Furthermore, this dimensional setting range for gap g not only effectively regulates the amount of expansion and deformation of the loose-fit lens 18 due to the annealing process after assembly of the lens unit as described above, but also allows the radially inward protrusion of the lens barrel material resulting from the roughening of the lens barrel 12 (particularly the blasting process) to contribute significantly to setting this dimensional range.

[0043] FIG. 4 shows a vehicle 240 as a moving body on which an in-vehicle system (imaging system) including an imaging device 250 including the camera module 300 of FIG. 3 is mounted. As shown in the figure, the imaging device 250 can be mounted on the vehicle 240, and FIG. 4 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 for monitoring the front when the vehicle 240 is traveling. The second imaging device 250b for monitoring the front may be disposed near the room mirror (inner rearview mirror) in the vehicle 240. The third imaging device 250c may be disposed on the dashboard or in the instrument panel as a camera for monitoring the driving situation of the driver. The fourth imaging device 250d may be disposed at the rear of the vehicle 240 for rear monitoring 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 captures the left rear side and a right side camera that captures the right rear side.

[0044] 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 an image signal (captured image) acquired by the imaging device 250, recognizes the image (recognizes an object in the captured image), and assists the driver in driving. The information processing device 242 is configured to output recognition information of an object in the captured image to the display device 243, and 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, for example. 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 be, but is not limited to, a liquid crystal display (LCD), an organic EL (Electro-Luminescence) display, or an inorganic EL display. The display device 243 can display to the driver (can output information to the 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.

[0045] Fig. 5 shows the configuration of an imaging device constituting the in-vehicle system of Fig. 4. 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 of Fig. 3 described above.

[0046] The control unit 252 controls the camera module 300 and processes an electrical signal output from the image sensor 304 of the camera module 80. 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). An application-specific integrated circuit is also called an application-specific integrated circuit (ASIC). The processor may include a programmable logic device. The 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 a system-on-a-chip (SoC) or a system in a package (SiP) 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.

[0047] 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.

[0048] As described above, the camera module 300 captures an object image formed via the lens unit 11 with the image sensor 304, and outputs the captured image. The image captured by the camera module 300 is also called a captured image.

[0049] 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.

[0050] 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 control unit 252 as a captured 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 11.

[0051] 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, in the present invention, the shapes and positions of the lens, the lens barrel, the step recess, and the like, as well as the form of the sealing material, are not limited to the above-mentioned embodiment. The above-mentioned configuration of the present invention is applicable between the outer peripheral surface of all lenses loosely fitted in the lens barrel and the inner peripheral surface of the lens barrel, and is not limited to the loosely fitted lens closest to the image side. In addition, 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]

[0052] 11 Lens unit 12 Telescope tube 12b Inner surface 12c Part of the inner surface of the telescope tube 18 Sixth lens (loose fit lens) 18b Outer surface 70 Adhesives (sealants) 242 Information processing equipment 243 Display device 250 Imaging Device 252 Control section 300 Camera Module 304 Package sensor (imaging element) g Gap L lens group O optical axis R Lens outer diameter S Inner storage space X Radial dimension of gap

Claims

1. A lens unit including a lens group including a plurality of lenses arranged along an optical axis, and a lens barrel having an inner storage space for storing and holding the lens group, a sealant is provided between an outer peripheral surface of a lens of the plurality of lenses that is loosely fitted in the lens barrel and an inner peripheral surface of the lens barrel so as to block a gas flow path from an image side to an object side; a portion of an inner peripheral surface of the lens barrel that comes into contact with the sealing material is roughened; a radial dimension of a gap between an outer peripheral surface of the loosely fitted lens and an inner peripheral surface of the lens barrel, which forms the gas flow passage, is set to 0.3% to 1.0% of an outer diameter of the loosely fitted lens; A lens unit characterized by:

2. 2. The lens unit according to claim 1, wherein the loosely fitted lens is a lens that constitutes the lens group and is positioned closest to the image side.

3. 2. The lens unit according to claim 1, wherein the surface roughening treatment is a blasting treatment.

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

5. An in-vehicle system installed in a vehicle, A camera module according to claim 4; 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