Lens units and camera modules

Abstract

To provide a lens unit and a camera module that can prevent dew condensation on a lens surface by suppressing the intrusion of water vapor into an inter-lens space between a lens located closest to an object and a lens adjacent to it.SOLUTION: A lens unit 11 of the present invention includes an annulus 60 fitted into outer circumferences of first and second lenses 13 and 14 so as to integrate the first lens 13 and the second lens 14 and cover a joint 70 of the first lens 13 and the second lens 14 from the outside. The annulus 60 includes seal portions 40, 42, 44, and 60B fitted into an inner peripheral surface of a lens barrel 12 and for sealing the inside of an inter-lens space S1 between the first lens 13 and the second lens 14 from the outside.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a lens unit and a camera module that can constitute an on-board camera mounted on a vehicle such as an automobile. [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] In particular, in a lens unit for an in-vehicle camera, when at least a portion of the lens unit is installed outside the vehicle, an O-ring 104 is inserted between the first lens 100, which is positioned closest to the object side of the lens group L, and the lens barrel 102 in a state in which the lens group L is assembled and housed and held in the inner housing space S of the lens barrel 102, as shown in Fig. 3, for waterproofing and dustproofing, so as to prevent water and dust from entering the lens group L inside the lens barrel 102. In this case, for example, an outer peripheral side surface 100a of the first lens 100 is provided with a stepped reduced diameter portion 100b whose diameter is reduced at the image side portion of the lens 100, and an O-ring 104 is attached to this reduced diameter portion 100b, and the O-ring 104 is compressed in the radial direction between the outer peripheral side surface 100a of the first lens 100 and the inner peripheral surface 102a of the lens barrel 102, so that the object side end of the lens barrel 102 is sealed.

[0004] Furthermore, with the lens group L assembled and housed within the inner housing space S of the lens barrel 102, a crimping portion 123 at the object side end (the upper end in FIG. 7) of the lens barrel 102 is crimped radially inward, thereby fixing the first lens 100 to the object side end of the lens barrel 102 by this crimping 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 104 as described above, moisture (water vapor) can enter the lens unit through various routes. Therefore, when the difference between the outside air temperature and the temperature inside the lens unit becomes large, the water vapor inside the lens unit 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 include the temperature inside the lens unit rising in winter when the outside air is cold, the temperature inside the lens unit rising due to heat transmitted from an image sensor (image pickup element) that is always powered for receiving light focused through the lens unit and converting it into an electrical signal, or the first lens 100 being cooled when the surface 100d of the first lens 100 is exposed to the outside air, rain, etc. when the temperature inside the lens unit is high due to heat from the image sensor or the surrounding environment (for example, a vehicle engine).

[0008] Examples of paths that allow water vapor to enter the lens unit include a path that passes from the gap between the crimped portion 123 of the lens barrel 102 and the first lens 100 through a part of the periphery of the O-ring 104 and the gap between the first lens 100 and the lens barrel 102 and / or the second lens 101 to the inter-lens space S1, or a path via the moisture-permeable resin that forms the lens barrel 102. Furthermore, the image sensor (imaging element) arranged on the image side of the lens unit rises to about 100 degrees during operation, and at that time, moisture contained in the substrate on which the image sensor is mounted turns into water vapor and reaches the inter-lens space S1 through the gap between the lens barrel 102 and each lens of the lens group L.

[0009] In any case, if water vapor enters the lens unit through such a route and a temperature difference occurs between the outside air and the inside of the lens unit 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 and suppress the intrusion of water vapor into the inter-lens space S1.

[0010] The present invention has been made in consideration of the above-mentioned circumstances, and aims to provide a lens unit and camera module that can prevent condensation on the lens surface by suppressing the intrusion of water vapor into the inter-lens space between the lens positioned closest to the object and the adjacent lens. [Means for solving the problem]

[0011] In order to achieve the above object, the present invention provides a lens unit comprising a lens group including a plurality of lenses arranged along an optical axis, and a cylindrical lens barrel having an internal storage space for storing and holding the lens group, the lens group including a first lens located closest to the object side, and a second lens adjacent to the first lens on its image side, a ring-shaped body that is fitted to an outer periphery of the first lens and the second lens so as to integrate the first lens and the second lens and cover a joint portion between the first lens and the second lens from the outside, The annular body is fitted to the inner peripheral surface of the lens barrel and has a seal portion for sealing the space between the first lens and the second lens from the outside.

[0012] According to the above-mentioned configuration of the present invention, the first lens and the second lens are integrated by the ring-shaped body fitted to the outer periphery of the first and second lenses, and the joint between the first lens and the second lens is covered (closed) from the outside, so that the ring-shaped body can block water vapor that tries to enter the inter-lens space between the first lens and the second lens through a path from the outside of the lens barrel to the inside of the lens barrel and a path within the inner storage space of the lens barrel, particularly a path from a substrate carrying an image sensor (imaging element) arranged on the image side of the lens unit to the object side via a gap between the lens barrel and each lens of the lens group L. Moreover, the ring-shaped body is provided with a seal portion for sealing the inter-lens space between the first lens and the second lens from the outside, so that even in a high humidity environment, the intrusion of water vapor into the inter-lens space is suppressed (improving airtightness), the amount of water vapor in the inter-lens space is reduced, and condensation on the lens surface, particularly condensation on the image-side surface (rear surface) of the first lens, can be suppressed. Therefore, it is possible to prevent the deterioration of visibility, such as the captured image becoming blurred and the desired resolution not being obtained. Also, if the first and second lenses can be integrated into a unit by the annular body in this way, it is possible to perform an airtightness test (a test to check the airtight state (anti-fogging performance)) on this unit alone, that is, before assembly of the entire lens unit, rather than after assembly.

[0013] The annular body may be made of metal or resin, but is preferably made of metal, because forming the annular body from resin raises concerns about deterioration of anti-fogging performance due to its hygroscopicity, whereas forming the annular body from metal can suppress such deterioration of anti-fogging performance.

[0014] In the above configuration, the seal portion preferably has a seal member and / or adhesive interposed between the inner surface of the annular body and the outer surface of the first lens, and between the inner surface of the annular body and the outer surface of the second lens, respectively, to keep the gaps airtight. This makes it possible to effectively and simply achieve an airtight state by the seal portion, and to reliably prevent water vapor from entering the inter-lens space through the gaps between the annular body and the first and second lenses. Examples of the seal member include an O-ring and a gasket, and examples of the adhesive include an adhesive for ensuring airtightness, such as an epoxy adhesive.

[0015] In the above configuration, the seal portion preferably has an annular blocking wall portion for blocking warm air containing water vapor flowing from the image side to the object side in the inner accommodation space. With this, the blocking wall portion blocks the warm air containing water vapor flowing from the image side to the object side in the inner accommodation space, so that it is possible to not only suppress the intrusion of water vapor into the inter-lens space and reduce the amount of water vapor in the inter-lens space, but also to prevent the difference between the outside air temperature and the temperature in the lens unit from becoming large, and in particular to make the temperature change in the inter-lens space gentle, thereby effectively preventing condensation from occurring in the inter-lens space, particularly on the back surface of the first lens.

[0016] In the above configuration, it is preferable that the blocking wall also serves as a spacer that is interposed between the second lens and the third lens adjacent to the second lens on the image side and separates these lenses in the optical axis direction. In this way, since the blocking wall also serves as a spacer that separates the second lens and the third lens in the optical axis direction, the two functions of the temperature difference suppression function and the spacer function described above can be achieved by only one part of the annular body called the blocking wall. This contributes to a reduction in the number of parts of the lens unit, and is particularly beneficial in the inner storage space where space is restricted.

[0017] In the above configuration, the sealing portion preferably has a sealing member and / or adhesive interposed between the blocking wall portion and the second lens and / or the third lens to keep the space airtight. This ensures airtightness of the water vapor distribution path involving the second lens and / or the third lens, and further improves the airtightness performance that prevents water vapor from entering the space between the lenses.

[0018] In the above configuration, it is preferable that an adhesive for maintaining airtightness is interposed between the outer surface of the ring-shaped body and the inner surface of the lens barrel, whereby the airtight adhesive can simultaneously block the flow of water from the outside of the lens barrel to the inside of the lens barrel and the flow of warm air from the image side (image sensor side) to the object side within the inside of the lens barrel.

[0019] A camera module according to the present invention includes the lens unit. With this configuration, the effects of the lens unit described above can be obtained with the camera module. Effect of the Invention

[0020] According to the present invention, the first lens and the second lens are integrated by an annular body that is fitted around the outer periphery of the first and second lenses, thereby covering the joint between the first lens and the second lens from the outside, and a sealing portion is provided on the annular body for sealing the inter-lens space between the first lens and the second lens from the outside, thereby suppressing the intrusion of water vapor into the inter-lens space between the first lens and the second lens and preventing condensation on the lens surface. [Brief description of the drawings]

[0021] [Figure 1] 1 is a schematic half-sectional view of a lens unit according to an embodiment of the present invention. [Diagram 2] 2 is a schematic half-sectional view of a camera module having the lens unit of FIG. 1. [Diagram 3] FIG. 1 is a schematic cross-sectional view showing an example of a conventional lens unit. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The lens unit of the present embodiment described below is particularly for 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 multiple lenses in Figures 1 to 3.

[0023] FIG. 1 shows a lens unit 11 according to an 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, metal (in this embodiment, the inner peripheral surface is circular), and a plurality of lenses (with circular outer peripheral surfaces) arranged in the inner storage space S of the lens barrel 12, for example, six lenses consisting of 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 from the object side. These lenses 13 to 18 are incorporated in the lens barrel 12 so as to be stacked with spacers 20A, 20B, and 20C interposed between some of them. An in-vehicle camera including 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. In this embodiment, the spacers 20A, 20B, and 20C may also function as a "light blocking diaphragm" that blocks light rays that cause ghosts or light rays that cause aberrations, and as an "aperture diaphragm" that limits the amount of transmitted light and determines the F-number, which is an index of brightness.

[0024] The lenses 13, 14, 15, 16, 17, and 18 are assembled and stored 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 lenses 13, 14, 15, 16, 17, and 18 constituting the lens group L are all made of glass, but this is not necessary, and they may be partly made of glass and partly made of resin, or all made of resin. In this embodiment, the two fourth and fifth lenses 16 and 17 located on the image side are laminated lenses, but this is not necessary. In this embodiment, the lens barrel 12 is made of metal as described above, but it may be made of resin. The surfaces of the lenses 13, 14, 15, 16, 17, and 18 may be provided with an anti-reflection film, a hydrophilic film, a water-repellent film, or the like, as required.

[0025] A substantially cylindrical cap 23 is screwed onto the object side end 12b (upper end in FIG. 1) of the lens barrel 12 as a fastening member, and the first lens 13 located closest to the object side is fixed to the object side end 12b of the lens barrel 12 by this cap 23. Specifically, the cap 23 has a female thread 23a formed on the inner peripheral surface of its peripheral side wall screwed into a male thread 12a formed on the outer peripheral surface of the object side end 12b of the lens barrel 12, and a tapered end surface 29 of a radially inner peripheral edge portion 23b of its flange-like upper end is abutted against a surface 13b of the first lens 13 facing the object side, and the first lens 13 is fixed to the object side end 12b by fastening this cap 23, and the lens group L is held within the lens barrel 12 in the optical axis direction.

[0026] An inner flange portion 24 having an opening with an outer diameter smaller than that of sixth lens 18 is provided at the end (lower end in FIG. 1) on the image side of lens barrel 12, and multiple lenses 13, 14, 15, 16, 17, 18 and spacers 20A, 20B, 20C constituting lens group L are sandwiched and held in the optical axis direction between inner flange portion 24 and cap 23. An outer flange portion 25 is provided on the outer peripheral surface on the image side of lens barrel 12 in the shape of a brim and is used when installing lens barrel 12 in an in-vehicle camera.

[0027] 2 is a schematic cross-sectional view of a camera module 300 according to the present embodiment having the lens unit 11 configured as described above. As shown in the figure, the camera module 300 includes the lens unit 11 of FIG. 1 to which a filter 99 is attached.

[0028] 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 packaged image sensor (imaging element) 304.

[0029] Upper case 301 is a member that exposes the object side end of lens unit 11 and covers 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. Sealing member 303 is a member that is interposed between inner surface 301a of upper case 301 and outer peripheral surface 12c of barrel 12 of lens unit 11, and is a member that maintains airtightness inside upper case 301.

[0030] Image 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. Image sensor 304 also includes a CCD, CMOS, or the like, and converts light that is collected and reaches it through lens unit 11 into an electrical signal. The converted electrical signal is then converted into analog data or digital data, which is a component of image data captured by the camera.

[0031] In the lens unit 11 and camera module 300 configured as described above, the first lens 13 located closest to the object side and the second lens 14 adjacent to the first lens 13 on the image side thereof have annular abutment surfaces (opposing surfaces) 13a, 14a that face each other in the optical axis direction and form a joint 70 between the first lens 13 and the second lens 14. The first lens 13 and the second lens 14 form an interlens space S1 between them. As described above, there are various paths that allow water vapor to enter the interlens space S1, but in order to prevent deterioration of visibility, such as condensation occurring in the interlens space S1, particularly on the back surface 13d of the first lens 13, causing the captured image to become blurred and making it impossible to obtain the desired resolution, it is necessary to suppress the intrusion of water vapor into the interlens space S1. However, moisture may enter the lens barrel 12 through a path from the outside of the lens barrel 12 to the inside of the lens barrel 12, particularly through the gap between the lens barrel 12 and the first lens 13. In addition, in the case of an assembly configuration in which the glass lenses 13, 14, 15, 16, 17, and 18 are fitted into the metal lens barrel 12 as in this embodiment, there are slight gaps between the lens barrel 12 and the lenses 13, 14, 15, 16, 17, and 18 to enable them to be fitted together, and moisture may enter the lens barrel 12 through such gaps. In the case where the lens makes point contact with the lens barrel 12 in the circumferential direction in a cross section perpendicular to the optical axis direction (i.e., in a cross section perpendicular to the optical axis direction, the inner surface of the lens barrel 12 is polygonal and the lens is circular, or there is point contact by a protruding rib provided on the inner circumference of the lens barrel 12), thereby forming a gap between the lens barrel 12 and the inner surface in the radial direction (and therefore a communicating passage extending continuously along the optical axis direction), moisture contained in the substrate of the image sensor 304 (see Figure 2), which is constantly powered, can be vaporized by heating the substrate and enter the inner storage space S through such a gap.

[0032] Therefore, in this embodiment, a structure is provided that can block water vapor that attempts to enter the inter-lens space S1 through various possible routes, which will be described in detail below. The lens unit 11 and camera module 300 configured as described above include a metal ring-shaped body 60 that is fitted to the outer peripheries of the first and second lenses 13, 14 so as to integrate the first lens 13 and the second lens 14 and cover from the outside a joint 70 between the first lens 13 and the second lens 14. That is, in this embodiment, the first lens 13, the second lens 14, and the ring-shaped body 60 are configured as one unit. In this case, the annular body 60 comprises a first extension portion 60A extending in the optical axis direction along the outer peripheral side surfaces of the first and second lenses 13, 14 so as to close the radially outer edges of the abutment surfaces 13a, 14a forming the joint 70 from the outside, and a second extension portion 60B extending radially inward from the image side end of the first extension portion 60A so as to form the aforementioned spacer 20C that is interposed between the second lens 14 and the third lens 15 adjacent to the second lens 14 on its image side and separates these lenses 14, 15 from each other in the optical axis direction, and is fitted into the inner peripheral surface 12d of the lens barrel 12 and has a plurality of sealing portions for sealing the inter-lens space S1 between the first lens 13 and the second lens 14 from the outside.

[0033] Specifically, the first seal portion is formed by the second extension portion 60B, which also serves as the spacer 20C. This second extension portion 60B extends radially along the surface 14b of the second lens 14 facing the image side, and forms an annular blocking wall portion for blocking warm air containing water vapor that flows from the image side to the object side through the gap between the lens barrel 12 and the lens in the inner housing space S. In addition, this blocking wall portion has an abutment portion 60Ba that abuts against the surface 14b of the second lens 14.

[0034] The second seal portion 40 has an O-ring 50 as a seal member that is inserted between the inner surface 60a of the annular body 60 and the outer peripheral side surface 13c of the first lens 13 to keep the gap airtight. In this case, the O-ring 50 is fitted into a step portion 60c formed at the object side end of the inner surface 60a of the first extension portion 60A of the annular body 60, and is radially compressed between the outer peripheral side surface 13c of the first lens 13 and the inner surface 60a of the annular body 60 to seal the gap, thereby preventing fine particles such as water and dust from entering the annular body 60 from the object side end of the lens unit 11. An airtight adhesive may be used instead of the O-ring 50.

[0035] The third seal portion 42 has an adhesive 52 that is interposed between the inner surface 60a of the annular body 60 and the outer surface (surface facing the image side) 14b of the second lens 14 to keep the space airtight. In this case, the adhesive 52 is filled in a recess 60ab formed in the inner surface 60a of the second extension portion 60B of the annular body 60. A seal member such as an O-ring may be used instead of the adhesive 52. The adhesive 52 may be interposed between the outer peripheral side surface of the second lens 14 and the inner surface 60a of the first extension portion 60A of the annular body 60.

[0036] The fourth seal portion 44 has an O-ring 54 as a seal member that is inserted between the second extension portion 60B, which is also the blocking wall portion and the spacer 20C, and the surface 14b of the second lens 14 facing the image side to keep the gap airtight. In this case, the O-ring 54 is fitted into a step portion 60Bb formed on the inner surface (surface facing the object side) of the second extension portion 60B of the annular body 60. Also, although not shown, instead of this or in addition to this, an O-ring may be provided as a fourth seal portion or a further seal portion as a seal member that is inserted between the second extension portion 60B and the surface 15a of the third lens 15 facing the object side to keep the gap airtight. In this case, the O-ring is fitted into a step portion formed on the outer surface (surface facing the image side) of the second extension portion 60B of the annular body 60. Note that an airtight adhesive may be used instead of the O-ring 54.

[0037] In this embodiment, an adhesive 80 for maintaining airtightness is interposed between the outer surface 60b of the ring-shaped body 60 and the inner peripheral surface 12d of the lens barrel 12. This allows the airtight adhesive 80 to simultaneously block the flow of water from the outside of the lens barrel 12 toward the inside of the inner storage space S of the lens barrel 12 and the flow of warm air from the image side (image sensor 304 side) toward the object side within the inner storage space S. In addition to this adhesive 80, a drainage channel 46 may be formed in the threaded portions 12a, 23a that are the screwed portions between the cap 23 and the lens barrel 12 so as to allow the flow of water from the outside of the lens barrel 12 toward the inside of the inner storage space S of the lens barrel 12 to escape to the outside again.

[0038] As described above, according to this embodiment, the first lens 13 and the second lens 14 are integrated by the annular body 60 which is fitted onto the outer periphery of the first and second lenses 13, 14, and the joint 70 between the first lens 13 and the second lens 14 is covered (closed) from the outside, so that the annular body 60 can block water vapor which attempts to enter the inter-lens space S1 between the first lens 13 and the second lens 14 via a path from the outside of the lens barrel 12 to the inside of the lens barrel 12, and a path within the inner storage space S of the lens barrel 12, in particular, a path from a substrate mounting an image sensor (imaging element) 304 arranged on the image side of the lens unit 11 to the object side via the gaps between the lens barrel 12 and each lens of the lens group L. Moreover, the annular body 60 is provided with the seal parts 40, 42, 44, 60B for sealing the space S1 between the first lens 13 and the second lens 14 from the outside, so that even in a high humidity environment, the intrusion of water vapor into the space S1 between the lenses is suppressed (improving airtightness), the amount of water vapor in the space S1 between the lenses is reduced, and condensation on the lens surface, particularly on the surface (back surface) 13d on the image side of the first lens 13, can be suppressed. Therefore, it is possible to prevent the deterioration of visibility, such as the captured image becoming blurred and the desired resolution not being obtained. In addition, if the first and second lenses 13 and 14 can be integrated into a unit by the annular body 60 in this way, an airtightness test (a test to confirm the sealed state (anti-fogging performance)) in the space S1 between the lenses can be performed on this unit alone, that is, before the lens unit 11 is assembled, not after the entire unit is assembled.

[0039] Furthermore, in this embodiment, since the annular body 60 is made of metal, deterioration of the anti-fogging performance caused by the hygroscopicity of resins can be suppressed.

[0040] In addition, in this embodiment, the annular body 60 is provided with second and third sealing portions 40, 42 having sealing members 50 and / or adhesives 52 interposed between the inner surface 60a of the annular body 60 and the outer surface of the first lens 13, and between the inner surface 60a of the annular body 60 and the outer surface of the second lens 14, respectively, to keep the spaces airtight. Therefore, an airtight state can be effectively and easily achieved, and water vapor can be reliably prevented from entering the inter-lens space S1 through the gaps between the annular body 60 and the first and second lenses 13, 14.

[0041] In addition, in this embodiment, the annular body 60 has an annular blocking wall portion 60B as a first sealing portion for blocking warm air containing water vapor flowing from the image side to the object side within the inner storage space S. This not only suppresses the intrusion of water vapor into the inter-lens space S1 and reduces the amount of water vapor in the inter-lens space S1, but also prevents the difference between the outside air temperature and the temperature within the lens unit 11 from becoming large, and in particular, it allows the temperature change in the inter-lens space S1 to be made gradual, thereby effectively preventing condensation from occurring within the inter-lens space S1, particularly on the back surface 13d of the first lens 13.

[0042] In the present embodiment, the blocking wall portion 60B also serves as the spacer 20C that is interposed between the second lens 14 and the third lens 15 and separates these lenses 14, 15 in the optical axis direction, so that the two functions of the temperature difference suppression function and the spacer function described above can be achieved by only one part of the annular body 60, that is, the blocking wall portion. This contributes to a reduction in the number of parts of the lens unit 11, and is particularly beneficial in the inner housing space S where space is restricted.

[0043] Furthermore, in this embodiment, the annular body 60 is provided with a fourth seal portion 44 having a seal member 54 interposed between the blocking wall portion 60B and the second lens 14 (in other embodiments not shown, the second lens 14 and / or the third lens 15) to keep the space between them airtight. This also ensures airtightness of the water vapor distribution path involving the second lens 14 (and / or the third lens 15), thereby further improving the airtightness performance that suppresses the intrusion of water vapor into the inter-lens space S1.

[0044] The present invention is not limited to the above-described 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 lens barrel, and the ring-shaped body are not limited to the above-described embodiment. In the above-described embodiment, the first lens is fixed to the object side of the lens barrel by a cap, which is a fastening member. However, when the lens barrel is made of resin, the first lens may be fixed to the object side of the lens barrel by a crimped portion at the object side end of the lens barrel that is crimped radially inward. In addition, the above-described embodiments may be combined in part or in whole, or a part of the configuration may be omitted from one of the above-described embodiments, without departing from the scope of the present invention. [Explanation of symbols]

[0045] 11 Lens unit 12 Telescope tube 13 The First Lens 14 The Second Lens 15 The Third Lens 40, 42, 44 Seal part 50,54 Seal member 52,80 Adhesive 60 Circular bodies 60B Blocking wall part (spacer, seal part) 70 Joint 300 Camera Module L lens group O optical axis S Inner storage space S1 Interlens Space

Claims

1. A lens unit comprising a lens group consisting of a plurality of lenses arranged along an optical axis, and a cylindrical lens barrel having an internal storage space for storing and holding the lens group, the lens group having a first lens located closest to the object side, and a second lens adjacent to the first lens on the image side, a ring-shaped body that is fitted to an outer periphery of the first lens and the second lens so as to integrate the first lens and the second lens and cover a joint portion between the first lens and the second lens from the outside, the annular body is fitted to an inner peripheral surface of the lens barrel, and comprises a first extending portion extending in the optical axis direction along the outer peripheral side surfaces of the first and second lenses so as to fit with these lenses, and a second extending portion extending radially inward from an image side end of the first extending portion so as to be interposed between the second lens and a third lens adjacent to the second lens on its image side and to fit with these lenses; A lens unit characterized in that a sealing member and / or adhesive is provided between the first lens and the first extension portion of the annular body, and between the second lens and the second extension portion of the annular body, for keeping the space between the lens and the annular body airtight and sealing the space between the first lens and the second lens from the outside.

2. The lens unit according to claim 1 , wherein the second extension portion forms an annular blocking wall portion for blocking warm air containing water vapor flowing from the image side to the object side within the inner accommodation space.

3. 3. The lens unit according to claim 2, wherein the blocking wall portion also serves as a spacer that separates the second lens and the third lens in the optical axis direction.

4. 4. The lens unit according to claim 1, wherein an adhesive is interposed between an outer surface of the annular body and an inner surface of the lens barrel to maintain airtightness.

5. A camera module comprising the lens unit according to claim 1 .

Images