JP7244607B2 - Lens unit and camera module - Google Patents

Description

TECHNICAL FIELD The present invention relates to a compact lens unit that is installed in the interior of an automobile.

In recent years, vehicles are equipped with in-vehicle cameras to support parking and prevent collisions through image recognition.
A camera module such as an in-vehicle camera generally includes a lens group composed of a plurality of lenses arranged along an optical axis, and a barrel housing the lens group. .

As an example of a conventional lens unit, one described in Patent Document 1 is known. In this lens unit, four lenses are held in a row in a lens barrel with their optical axes aligned.
In addition, since such a lens unit is attached to an on-vehicle camera outside the automobile and is exposed to the elements, a first lens unit that seals between the lens barrel and the object-side lens located closest to the object side among the plurality of lenses is provided. and a second seal portion located closer to the image side than the sealing position of the seal member of the first seal portion, thereby ensuring the airtightness in the lens barrel. Prevents water and dust from entering.

By the way, a camera installed in the interior of an automobile, such as a camera for monitoring a driver, is not exposed to the elements. For this reason, in such a camera, there is not much need to ensure the airtightness of the inside of the lens barrel. Conventionally, a seal for ensuring the airtightness is not provided as shown in FIG. 3, for example.
That is, as shown in FIG. 3, a conventional lens unit 10 includes a lens barrel 1 and a lens group 5 consisting of a plurality of (three) lenses 2 to 4 arranged in the lens barrel 1. .
An intermediate ring (spacer) 6 is provided between the lenses 2 and 3 , and an intermediate ring (spacer) 7 is provided between the lenses 3 and 4 .
These lenses 2 to 4 and spacers 6 and 7 are inserted through an opening on the image side (lower side in FIG. 3) of lens barrel 1, and adjacent lenses and spacers are in contact with each other.
No sealing member such as an O-ring is provided between the lens closest to the object (object-side lens) 2 and the inner peripheral surface of the barrel 1. Confidentiality is not ensured.
An optical filter 8 is provided in the opening of the lens barrel 1 on the image side, and an intermediate ring (spacer) 9 is provided between the optical filter 8 and the lens 4 .

JP 2013-231993 A

By the way, in recent years, high quality such as high resolution has been demanded even for compact cameras installed in the interior of automobiles. The demand for sexuality is increasing.
However, in the conventional lens unit 10, as shown in FIG. It is difficult to form a stepped portion (recess) for housing a sealing member (such as an O-ring) on the outer peripheral portion of the object-side lens 2 .
For this reason, it is conceivable to increase the thickness of the object-side lens 2 in the optical axis direction and form a stepped portion (recess) for the seal member. is longer in the optical axis direction, and the size of the lens unit 10 is increased.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a lens unit in which a seal member can be easily provided between the object-side lens and the inner peripheral surface of the lens barrel without increasing the size of the lens unit. intended to provide

In order to solve the above-described problems, the lens unit of the present invention includes a plurality of lenses arranged along an optical axis, a lens barrel housing the plurality of lenses, and a lens unit closest to the object side of the plurality of lenses. A lens unit comprising: a sealing member provided between a positioned object-side lens and an inner peripheral surface of the lens barrel,
A groove portion having a depth in the optical axis direction is provided along the circumferential direction of the lens barrel on the inner surface side of the lens barrel,
A part of the seal member is housed in the groove.

In the present invention, a seal member is provided between the object-side lens and the inner peripheral surface of the lens barrel in a groove portion that is provided along the circumferential direction on the inner surface side of the lens barrel and has a depth in the direction of the optical axis. Since the lens unit is partially housed, the sealing member can be easily provided between the object-side lens and the inner peripheral surface of the lens barrel without increasing the size of the lens unit.

In the above configuration of the present invention, it is preferable that a gap is provided between the bottom surface of the groove and part of the seal member accommodated in the groove.

According to such a configuration, since a gap is provided between the bottom surface of the groove and a part of the seal member accommodated in the groove, the seal member is perpendicular to or intersects the axial direction of the lens barrel. There is no pressure contact. Therefore, it is possible to prevent a force in the optical axis direction from acting on the object-side lens from the seal member due to this, so that high positioning accuracy of the object-side lens in the optical axis direction can be maintained.

Further, in the configuration of the present invention, a flange portion protruding toward the inner peripheral side of the lens barrel is provided at the object-side end portion of the lens barrel,
The groove portion may be provided on the lower surface of the flange portion opposite to the object side.

According to such a configuration, since the groove is provided on the lower surface of the flange that protrudes toward the inner circumference of the lens barrel, the groove can be easily provided, and the object-side lens is brought into contact with the flange. As a result, the object-side lens can be easily and reliably positioned in the optical axis direction, and the flange portion can have a narrowing function.

According to the present invention, the sealing member can be easily provided between the object-side lens and the inner peripheral surface of the lens barrel without enlarging the lens unit.

1 shows a lens unit according to an embodiment of the present invention, where (a) is a schematic cross-sectional view and (b) is an enlarged view of a main part in FIG. 1. FIG. FIG. 4 is a schematic cross-sectional view showing lenses of a lens unit of a reference example; and FIG. 11 is a schematic cross-sectional view showing a conventional lens unit.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings.
The lens unit of this embodiment is for a camera module such as a camera for monitoring a driver of an automobile, and the camera module is installed in the interior of the automobile.
Further, as shown in FIG. 1, the lens unit 20 of the present embodiment includes a cylindrical lens barrel 21 and a lens group consisting of a plurality of (three) lenses 22 to 24 arranged in the lens barrel 21. 25.
An intermediate ring (spacer) 26 is provided between the lens 23 and the lens 24 .
An optical filter (infrared cut filter) 27 is provided at the image side opening of the lens barrel 21 , and an intermediate ring (spacer) 28 is provided between the optical filter 27 and the lens 24 .

A plurality of lenses 22 to 24 fixed and supported by the lens barrel 21 are arranged with their optical axes aligned, and the lenses 22 to 24 are arranged along one optical axis. In this state, it constitutes one lens group 25 used for imaging. Therefore, when simply referred to as an optical axis below, it indicates the optical axis of each of the lenses 22 to 24 and the optical axis of the lens group 25 .

The lens barrel 21 is a cylindrical member with openings at both ends, and has an opening 21a at an end (one end) on the object side (outside, incident side) and an end on the image side (inner side, exit side). It has an opening 21b at (the other end). At the object-side end of the lens barrel 21, a diameter-reduced portion 21c is formed to narrow the opening 21a. formed. Note that the opening 21a is narrower than the opening 21b.
A flange portion 30 protruding toward the inner periphery of the lens barrel 21 is provided at the end of the lens barrel 21 on the object side. is provided.

Inside the lens barrel 21, a plurality (five) of cylindrical storage portions 31a to 31e having different diameters are provided. The accommodating portions 31a to 31e are arranged in this order continuously from the opening 21a side of the lens barrel 21 toward the opening 21b side, and their diameters increase in this order.
The lens 22 is accommodated in the accommodation portion 31a with its outer peripheral surface in contact with the inner peripheral surface of the accommodation portion 31a, and the lens 23 is accommodated in the accommodation portion 31b with its outer peripheral surface in contact with the inner peripheral surface of the accommodation portion 31b. It is contained in good condition.
The inner peripheral surface of the housing portion 31c has a substantially conical upper portion and a cylindrical lower portion. The intermediate ring 26 contacts the housing portion 31c with its cylindrical outer peripheral surface against the lower inner peripheral surface of the housing portion 31c, and has a conical outer peripheral surface with a gap between it and the upper inner peripheral surface of the housing portion 31c. Contained in good condition. Further, part of the downwardly convex lens portion of the lens 23 is accommodated in part of the accommodating portion 31c.
Further, the lens 24 is accommodated in the accommodating portion 31d with its outer peripheral surface in contact with the inner peripheral surface of the accommodating portion 31d, and the intermediate ring 28 contacts the inner peripheral surface of the accommodating portion 31e with its outer peripheral surface in the accommodating portion 31e. They are housed in close contact.
In this manner, the lenses 22-24 and intermediate rings 26, 28 are radially positioned.

The lens (object-side lens) 22 is a glass-polished lens, and a stepped portion 22a for accommodating an O-ring (seal member) 35 is formed along the circumferential direction on the outer peripheral flange portion. The stepped portion 22a has a cylindrical surface 22b provided coaxially with the optical axis direction and an annular surface 22c provided perpendicular to the optical axis direction. Connected by smooth arc surfaces.
Further, the flange portion of the lens 22 is formed with an annular surface 22d provided perpendicular to the optical axis direction on the inner peripheral side of the stepped portion 22a and closer to the convex spherical lens surface.
On the other hand, an annular convex portion 32 is formed along the circumferential direction on the lower surface of the flange portion 30 of the lens barrel 21 .
The lens 22 is inserted into the lens barrel 21 through the opening 21b on the image side, and the annular surface 22d of the lens 22 is brought into contact with the convex portion 32 to position the lens 22 in the optical axis direction.

The lens 23 is a glass molded lens, and is positioned in the optical axis direction by inserting it through the opening 21b of the lens barrel 21 and bringing the flange of the lens 23 into contact with the lower surface of the flange of the lens 22. there is
The intermediate ring 26 is inserted through the opening 21b of the lens barrel 21, and the upper end surface of the intermediate ring 26 is brought into contact with the lower surface of the flange portion of the lens 23, thereby positioning in the optical axis direction.

The lens 24, which is a plastic lens, is inserted through the opening 21b of the lens barrel 21 and is positioned in the optical axis direction by bringing the flange of the lens 24 into contact with the lower surface of the intermediate ring 26. FIG.
The intermediate ring 28 is inserted through the opening 21b of the lens barrel 21, and the upper surface of the intermediate ring 28 is brought into contact with the lower surface of the flange portion of the lens 24, thereby positioning in the optical axis direction.
The optical filter 27 is inserted through the opening 21b of the lens barrel 21, and the upper surface of the optical filter 27 is brought into contact with the lower surface of the intermediate ring 28, thereby positioning in the optical axis direction.
Further, the optical filter 27 is clamped and fixed between the crimped portion and the intermediate ring 28 by crimping the inner peripheral edge portion of the opening 21b of the lens barrel 21 .
In this way, the lenses 22-24, the intermediate rings 26, 28 and the optical filter 27 are positioned in the optical axis direction.

A groove portion 36 having a depth in the optical axis direction is provided along the circumferential direction of the lens barrel 21 on the inner surface side of the lens barrel 21 .
That is, on the lower surface of the flange portion 30 of the lens barrel 21 opposite to the object side (image side), a groove portion 36 having a rectangular cross section is provided along the circumferential direction outside the convex portion 32 in the radial direction. . The groove width of the groove portion 36 is substantially equal to the distance between the cylindrical surface 22b of the stepped portion 22a provided on the flange portion of the object-side lens 22 and the inner peripheral surface of the housing portion 31a. Therefore, between the flange portion of the object-side lens 22 and the inner peripheral surface of the accommodating portion 31a, a hollow portion having a vertically elongated rectangular cross section is provided.

An O-ring 35 serving as a sealing member is inserted into this hollow portion while being crushed in the radial direction of the lens barrel 21 . In this state, the outer peripheral surface of the O-ring 35 is in close contact with the inner peripheral surface of the housing portion 31 a , and the inner peripheral surface is in close contact with the cylindrical surface 22 b of the stepped portion 22 a of the object-side lens 22 .
The lower surface of the O-ring 35 is in contact with or in close contact with the annular surface 22c of the stepped portion 22a, and the upper surface of the O-ring 35 is provided with a gap S between it and the bottom surface 36a of the groove portion 36. As shown in FIG. That is, a gap S is provided between the bottom surface 36 a of the groove 36 and a portion (upper surface) of the O-ring 35 accommodated in the groove 36 .

In order to incorporate the O-ring 35 into the lens barrel 21, for example, before inserting the object-side lens 22 into the lens barrel 21, the O-ring 35 is fitted into the stepped portion 22a of the object-side lens 22, and the O-ring 35 is The inner peripheral surface of the stepped portion 22a is pressed against the cylindrical surface 22b of the stepped portion 22a, and the lower surface thereof is brought into contact or pressed against the annular surface 22c of the stepped portion 22a.
Then, by inserting the object-side lens 22 with the O-ring through the opening 21b of the lens barrel 21 and bringing the annular surface 22d of the object-side lens 22 into contact with the convex portion 32 of the lens barrel 21, the O-ring 35 is inserted into the cavity surrounded by the cylindrical surface 22b and the annular surface 22c of the stepped portion 22a, the inner peripheral surface of the housing portion 31a, and the groove portion . In this state, the O-ring 35 is crushed in the radial direction of the lens barrel 21, and the outer peripheral surface of the O-ring 35 is in close contact with the inner peripheral surface of the housing portion 31a. is in close contact with the cylindrical surface 22b of the stepped portion 22a. The lower surface of the O-ring 35 abuts or closely contacts the annular surface 22c of the stepped portion 22a, and the upper surface of the O-ring 35 is provided with a gap S between the bottom surface 36a of the groove portion 36 and the bottom surface 36a. As a result, airtightness inside the lens barrel 21 from the object side is ensured, and entry of water and dust into the lens barrel 21 is prevented.

As described above, according to the present embodiment, the groove 36 provided along the circumferential direction on the inner surface side of the lens barrel 21 and having a depth in the optical axis direction is provided with the object side lens 22 and the inner circumference of the lens barrel 21 . Since a part of the O-ring 35 provided between the object-side lens 22 and the lens barrel 21 is accommodated, the O-ring 35 can be placed between the object-side lens 22 and the inner peripheral surface of the lens barrel 21 without increasing the size of the lens unit 20. can be easily provided.
In addition, since a gap S is provided between the bottom surface 36a of the groove 36 and the top (upper surface) of the O-ring 35 housed in the groove 36, the O-ring 35 is perpendicular to or crosses the axial direction of the lens barrel 21. There is no pressure contact with the bottom surface 36a of the groove portion 36. As a result, it is possible to prevent the force from the O-ring 35 from acting on the object-side lens 22 in the optical axis direction, thereby maintaining high positioning accuracy of the object-side lens 22 in the optical axis direction.
Furthermore, since the groove 36 is provided on the lower surface of the flange 30 protruding to the inner peripheral side of the lens barrel 21, the groove 36 can be easily provided, and the object-side lens 22 is brought into contact with the flange 30. As a result, the object-side lens 22 can be easily and reliably positioned in the optical axis direction, and the flange portion 30 can be provided with a narrowing function.

(Reference example)
Next, a reference example will be described in which an O-ring (sealing member) can be easily provided between the object-side lens and the inner peripheral surface of the lens barrel without enlarging the lens unit.
The lens unit of this embodiment is for a camera module such as a camera for monitoring the driver of an automobile, and the camera module is installed in the interior of the automobile.
Further, as shown in FIG. 2, the lens unit 40 of the present embodiment includes a cylindrical lens barrel 41 and a lens group consisting of a plurality of (three) lenses 42 to 44 arranged in the lens barrel 41. 45. The lens 42 is a polished glass lens, the lens 43 is a molded glass lens, and the lens 44 is a plastic lens.
An optical filter 47 is provided at the image-side aperture of the lens barrel 41 , and an intermediate ring (spacer) 48 is provided between the optical filter 47 and the lens 24 .

A plurality of lenses 42 to 44 fixed and supported by the lens barrel 41 are arranged with their optical axes aligned, and the lenses 42 to 44 are arranged along one optical axis. In this state, it constitutes one lens group 45 used for imaging. Therefore, when simply referred to as an optical axis below, it indicates the optical axis of each of the lenses 42 to 44 and the optical axis of the lens group 45 .

The lens barrel 41 is a cylindrical member with openings at both ends, and has an opening 41a at an end (one end) on the object side (outside, incident side) and an end on the image side (inner side, exit side). It has an opening 41b at (the other end). The opening 41a is narrower than the opening 41b.
An inner flange portion 50 protruding inward is formed on the inner peripheral surface of the lens barrel 41 at a substantially central portion in the optical axis direction. It is a flat surface 50a.

Inside the lens barrel 41, a plurality (three) of cylindrical storage portions 49a to 41c having different diameters are provided. The diameters of the accommodating portions 49a to 41c increase in this order.
The lens 42 and the lens 43 are accommodated in the accommodation portion 49a with their outer peripheral surfaces in contact with the inner peripheral surface of the accommodation portion 49a. Thereby, the lenses 42 and 43 are positioned in the radial direction.
The flange portion of the lens 43 is in contact with the flat surface 50a of the inner flange portion 50, and the upper surface of the flange portion of the lens 43 is in contact with the lower surface of the outer peripheral portion of the lens 42. As shown in FIG. Thereby, the lenses 42 and 43 are positioned in the optical axis direction. Part of the lens portion of the lens 43 is located in the space between the housing portion 49a and the housing portion 49b.

A cover member 55 is inserted into the housing portion 49a from the upper end portion (the end portion on the object side) of the lens barrel 41. As shown in FIG.
The cover member 55 is formed in a substantially cylindrical shape, and its outer peripheral surface is welded to the inner peripheral surface of the lens barrel 41 (the inner peripheral surface of the housing portion 49a). Further, the inner peripheral portion of the upper end of the opening 41 b of the lens barrel 41 is crimped inwardly to be engaged with the outer peripheral portion of the upper end of the lid member 55 . In this manner, the lid member 55 is fixed to the housing portion 49a.
An inverted truncated cone-shaped hole 55a is formed in the radially central portion of the lid member 55, and the inner peripheral surface of the hole 55a is formed in a shape that functions as a throttle.
The lower surface of the lid member 55 is formed in an upwardly convex spherical shape, and two convex portions 55b and 55c are formed on the lower surface coaxially and radially with a predetermined interval. The convex portions 55 b and 55 c are in contact with the spherical upper surface of the lens 42 .

Further, the lens 44 is accommodated in the accommodating portion 49b with its outer peripheral surface in contact with the inner peripheral surface of the accommodating portion 49b, thereby positioning the lens 44 in the radial direction.
The upper surface of the flange portion of the lens 44 is in contact with the upper wall surface forming the housing portion 49b via the disk-shaped diaphragm member 46. This allows the lens 44 and the diaphragm member 46 to move in the optical axis direction. positioning is done.
The intermediate ring 48 is accommodated in the accommodating portion 49c with its outer peripheral surface in contact with the inner peripheral surface of the accommodating portion 49c, thereby positioning the intermediate ring 48 in the radial direction. The upper surface of the intermediate ring 48 is in contact with the lower surface of the flange portion of the lens 44, thereby positioning the intermediate ring 48 in the optical axis direction.

The outer peripheral surface of the optical filter 47 is in contact with the inner peripheral surface of the accommodating portion 49 c , and the upper surface of the outer peripheral portion is in contact with the lower surface of the intermediate ring 48 . by this. The optical filter 47 is positioned in the radial direction and the optical axis direction.

A stepped portion 42 a for accommodating an O-ring (seal member) 60 is formed along the circumferential direction on the outer peripheral portion on the image side of the lens (object-side lens) 42 . The stepped portion 42a has a cylindrical surface 42b provided coaxially with the optical axis direction and an annular surface 42c provided perpendicular to the optical axis direction. Connected by smooth arc surfaces.
An O-ring 60 is accommodated in a hollow portion between the stepped portion 42a and the inner peripheral surface of the lens barrel 41 (the inner peripheral surface of the accommodation portion 49a). In this state, the O-ring 60 is crushed in the radial direction of the lens barrel 41, and the outer peripheral surface of the O-ring 60 is in close contact with the inner peripheral surface of the housing portion 49a. is in close contact with the cylindrical surface 42b of the stepped portion 42a. As a result, airtightness inside the lens barrel 41 from the object side is ensured, and entry of water and dust into the lens barrel 41 is prevented.
In addition, the lower surface of the O-ring 60 abuts or closely contacts the upper surface of the flange portion of the lens 43, and a gap is provided between the upper surface and the annular surface 42c.

In order to incorporate the O-ring 60 into the lens barrel 41, for example, before inserting the object-side lens 42 into the lens barrel 41, the O-ring 60 is fitted into the stepped portion 42a of the object-side lens 42, and the O-ring 60 is is pressed against the cylindrical surface 42b of the stepped portion 42a.
First, the lens 43 is inserted through the opening 41b of the lens barrel 41 and comes into contact with the flat surface 50a of the inner flange portion 50, and then the object side lens 42 with the O-ring is inserted through the opening 41b of the lens barrel 41. By inserting the object-side lens 42 and bringing the lower surface (image-side surface) of the object-side lens 42 into contact with the flange portion of the lens 43, the O-ring 60 is placed between the cylindrical surface 42b and the annular surface 42c of the stepped portion 42a and the accommodating portion 49a. and the upper surface of the flange portion of the lens 43 . In this state, the O-ring 60 is crushed in the radial direction of the lens barrel 41, and the outer peripheral surface of the O-ring 60 is in close contact with the inner peripheral surface of the housing portion 49a. is in close contact with the cylindrical surface 42b of the stepped portion 42a. Further, the lower surface of the O-ring 60 abuts or closely contacts the upper surface of the flange portion of the lens 43, and a gap is provided between the upper surface and the annular surface 42c of the stepped portion 42a.
Further, the lid member 55 is inserted from the upper end (the end on the object side) of the lens barrel 41, and the convex portions 55b and 55c are brought into contact with the upper surface of the lens 42, and then the outer peripheral surface of the lid member 55 41 (the inner peripheral surface of the accommodating portion 49a), and crimps the upper inner peripheral portion of the opening 41b of the lens barrel 41 inward to lock the outer peripheral portion of the upper end of the lid member 55. As shown in FIG.
As a result, airtightness inside the lens barrel 41 from the object side is ensured, and entry of water and dust into the lens barrel 41 is prevented.

As described above, in this example, the lenses 42 and 43 are incorporated into the lens barrel 41 from the opening 41a on the object side of the lens barrel 41, and the cylindrical surface 42b of the stepped portion 42a provided on the outer peripheral portion of the lens 42 on the image side An O-ring 60 is provided in a hollow portion surrounded by the annular surface 42c, the inner peripheral surface of the accommodating portion 49a, and the upper surface of the flange portion of the lens 43, and the lid member 55 presses the lens 42 and closes the lid member 55. Since it is welded to the inner peripheral surface of the lens barrel 41, airtightness inside the lens barrel 41 from the object side can be ensured.
Further, the lens 42 has only one stepped portion 42a for providing an O-ring on the outer periphery on the image side. is not provided with a stepped portion. Therefore, since the lens 42 can be made thinner in the optical axis direction than the lens 22 of the embodiment, the inner peripheral surfaces of the object-side lens 42 and the lens barrel 41 can be adjusted without increasing the size of the lens unit 40 . An O-ring 60 can be easily provided between.
Further, since the lens 42 is provided with only one stepped portion 42a, the processing cost for forming the stepped portion can be reduced as compared with the lens 22 of the embodiment.

20 lens unit 21 barrel 22-24 lens 22 object side lens 30 flange 35 O-ring (sealing member)
36 Groove 36a Bottom S Gap

Claims (11)

A plurality of lenses arranged along the optical axis, a lens barrel housing the plurality of lenses, a first lens located closest to the object side among the plurality of lenses, and an inner peripheral surface of the lens barrel A lens unit comprising a sealing member provided between,
the first lens is inserted into the lens barrel from an opening on the object side of the lens barrel;
the first lens has a stepped portion along the circumferential direction on an outer peripheral portion on the image side opposite to the object side, and the sealing member is accommodated in the stepped portion;
a cylindrical lid member is inserted into the lens barrel from the opening,
the lid member is in contact with the surface of the first lens facing the object side;
The outer peripheral surface of the lid member is welded to the inner peripheral surface of the lens barrel,
By crimping the upper inner peripheral portion of the opening of the lens barrel inward, the upper outer peripheral portion of the lid member is locked,
at least one lens among the plurality of lenses is an image side lens inserted into the lens barrel from the image side;
a housing portion housing the image-side lens of the lens barrel has an upper wall surface perpendicular to the optical axis;
A lens unit, wherein the image-side lens is pressed against the upper wall surface. 2. The lens unit according to claim 1, wherein the image-side lens is longer than the first lens in a direction perpendicular to the optical axis. 3. The lens unit according to claim 1, wherein an inverted truncated conical hole is formed in the radially central portion of the lid member, and the inner peripheral surface of this hole functions as a diaphragm. an intermediate ring is provided on the lens barrel in contact with a surface of the image-side lens facing the image side;
4. The lens according to any one of claims 1 to 3, wherein an optical filter is provided in an image-side opening of the lens barrel in contact with a surface of the intermediate ring facing the image side. unit. An annular inner flange portion protruding radially inward is provided on the inner peripheral surface of the lens barrel,
5. The lens according to claim 1, wherein the first lens is positioned in the optical axis direction by being restricted from moving toward the image side by the inner flange portion. lens unit. A second lens adjacent to the first lens on the image side,
The second lens is in contact with the inner flange portion on the object side,
6. The optical system according to claim 5, wherein the first lens and the second lens are positioned in the optical axis direction by bringing the first lens into contact with the second lens on the object side. lens unit. 7. The stepped portion has a cylindrical surface provided coaxially with the optical axis direction and an annular surface provided perpendicular to the optical axis direction. 2. The lens unit according to item 1. 8. The lens according to claim 7 , wherein the outer peripheral surface of the seal member is in close contact with the inner peripheral surface of the lens barrel, and the inner peripheral surface of the seal member is in close contact with the cylindrical surface of the stepped portion. unit. 9. The lens unit according to claim 7, wherein a gap is provided between the annular surface of the stepped portion and the seal member. The image side surface of the lid member is formed with convex portions coaxially and radially at predetermined intervals, and the convex portions are in contact with the object side surface of the first lens. A lens unit according to any one of claims 1 to 9. A camera module comprising the lens unit according to any one of claims 1 to 10.

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