JP7446859B2 - lens unit - Google Patents

Description

The present invention relates to a lens unit.

Conventionally, techniques have been proposed for reducing lens play in lens units and lens holding structures. As such a technique, for example, a lens unit is known that has a resin barrel in which a plurality of lenses are incorporated, and in which the lenses are fastened together using a retainer (for example, see Patent Document 1).

Further, the above technology includes a lens having an optical surface and a non-optical surface, and a plurality of guide portions on one surface of the non-optical surface and a surface of the lens barrel facing the non-optical surface. A configuration is known in which the guide is provided integrally and an engaging portion that engages with the guide portion is provided on the other surface (see, for example, Patent Document 2).

In addition, the above technique includes a first lens holding member having an annular shape that presses and fixes the peripheral portion of the first lens, and a first lens holding member that extends while contacting the outer periphery of the first lens, and a second lens outer periphery angle. A lens holder is known that includes a second lens pressing member that presses and fixes the lens portion in the optical axis direction and radial direction (for example, see Patent Document 3).

JP 2019-179179 Publication JP2012-73543A Japanese Patent Application Publication No. 2010-78920

Lens units are exposed to temperature changes depending on the environment in which they are used. Even if such a temperature change occurs, it is required to suppress displacement of the lens in the lens unit.

However, in the technique of Patent Document 1, the plastic lens may be deformed because the lens is assembled by press-fitting. Furthermore, when expansion and contraction occur in the direction of compression of the plastic lens due to severe temperature changes, the plastic lens becomes more deformed, and therefore it is difficult to suppress the deformation of the plastic lens to a predetermined value or less.

Further, since the technique of Patent Document 2 does not have a biasing force in the optical axis direction, a change in the position of the lens and the optical axis may occur.

Furthermore, in the technique disclosed in Patent Document 3, since the plastic lens is pressed and fixed to the inner diameter of the lens barrel using an elastic member, the center of the lens may shift depending on expansion and contraction of the lens barrel.

One aspect of the present invention aims to provide a lens unit that can suppress displacement of a plastic lens due to temperature changes.

In order to solve the above problems, a lens unit according to one aspect of the present invention includes one or more plastic lenses, a lens barrel that accommodates the one or more plastic lenses, and a lens barrel that accommodates the one or more plastic lenses. one or more first fitting parts arranged on the outer edge of at least one of the lenses; and one or more first fitting parts arranged on the inner peripheral part of the lens barrel and fitted into each of the one or more first fitting parts. and a retainer that presses the one or more plastic lenses in the axial direction of the lens barrel and fixes them in the lens barrel.

According to one aspect of the present invention, displacement of a plastic lens due to temperature change can be suppressed.

1 is a cross-sectional view showing the configuration of a lens unit according to Embodiment 1. FIG. FIG. 2 is an exploded perspective view showing each component of the lens unit according to Embodiment 1 together with the main body of the imaging device. FIG. 2 is a rear view of the lens barrel of the lens unit according to Embodiment 1, viewed from the image plane side together with the main body of the imaging device. FIG. 3 is a cross-sectional view showing the configuration of a lens unit according to Embodiment 2. FIG. 7 is an exploded perspective view showing each component of the lens unit according to Embodiment 2 together with the main body of the imaging device. FIG. 7 is an exploded perspective view showing a first image plane side retainer included in a lens unit according to a modification of Embodiment 2 together with other components.

Embodiments of the lens unit according to the present invention will be described below. However, the lens unit described below is one aspect of the lens unit according to the present invention, and the lens unit according to the present invention is not limited to the following aspect.

[Embodiment 1]
(overall structure)
First, the overall configuration of a lens unit 100 according to this embodiment will be described with reference to FIGS. 1 and 2.

FIG. 1 is a cross-sectional view showing the configuration of a lens unit 100 according to this embodiment. More specifically, FIG. 1 shows a cut plane including a fitting portion between a first fitting part 140 and a second fitting part 180, which will be described later, and is cut along a cutting plane along the axial direction. FIG.

FIG. 2 is an exploded perspective view showing each component of the lens unit 100 in FIG. 1 together with the main body 210 of the imaging device.

As shown in FIG. 1, the lens unit 100 includes a plurality of lenses, an object-side retainer 10, a spacer 16, an image-side retainer 17, and a lens barrel 18. Lens unit 100 is configured to be held by main body 210.

(Composition of each part)
The plurality of lenses housed in the lens unit 100 are three glass lenses 11 to 13 and two plastic lenses 14 and 15. All of the above lenses have a configuration for determining the position in the radial direction. Examples of configurations for such positioning include a concave line and a convex line that fits therein, a hole and a boss that fits therein, a convex surface of a specific shape on one lens, and the above specified convex surface on the other lens adjacent to it. It includes a concave surface that matches the shape, an outer peripheral wall of the lens, and an inner peripheral wall of the lens barrel 18 that abuts the outer peripheral wall of the lens. In this way, the plurality of lenses are configured to be guided to specific positions determined in the radial direction when accommodated in the lens barrel 18.

Although two plastic lenses are shown in this embodiment, the number of plastic lenses is not limited to this, and the number of plastic lenses may be one or three or more.

The outer edge of the plastic lens 14 has a groove 140 extending along the thickness direction of the plastic lens 14. The grooves 140 are provided at three locations on the outer edge of the plastic lens 14. More specifically, the grooves 140 are provided at three-fold symmetrical positions with the center of the plastic lens 14 as the center of symmetry when viewed in plan. The groove 140 corresponds to a first fitting part.

The objective side retainer 10 is a substantially cylindrical body, and has a female thread formed on its inner peripheral surface. Furthermore, a convex portion that comes into contact with the glass lens is formed on the inner circumferential surface of the objective side opening of the objective side retainer 10.

The spacer 16 is a spacer interposed between the glass lens 12 and the glass lens 13. The spacer 16 forms a gap of a predetermined size between the glass lens 12 and the glass lens 13 in the axial direction. A plurality of (for example, six) convex portions are formed on the objective side edge of the spacer 16 that is in contact with the glass lens 12 .

The image side retainer 17 has a substantially cylindrical shape. Further, the image side retainer 17 is made of resin and has elasticity. The image plane side retainer 17 includes a fastening part 170 located on the image plane side and a cylindrical part 171 located on the object side.

The fastening portion 170 has a threaded portion 172 on its outer peripheral surface, and has a female thread on its inner peripheral surface. The threaded portion 172 is, for example, a male thread.

The cylindrical portion 171 is a cylindrical portion, and has a plurality (for example, six) of protrusions 174 arranged at equal intervals in the circumferential direction on its object-side end surface.

The lens barrel 18 is a substantially cylindrical member made of resin, and has openings at both ends on the object side and the image plane side. The lens barrel 18 can be made of fiber-reinforced resin, for example, but this does not limit the present embodiment.

A male thread is formed on the outer peripheral surface of the lens barrel 18 on the object side in the axial direction. The male thread is formed to be screwed into a female thread on the inner circumferential surface of the objective side retainer 10. Further, a female thread is formed on the inner circumferential surface of the lens barrel 18 on the image plane side in the axial direction. The female thread is formed to be threaded into the threaded portion 172 of the image side retainer 17 .

Here, FIG. 3 is a rear view of the lens barrel of the lens unit according to Embodiment 1, viewed from the image plane side together with the main body of the imaging device. As shown in FIG. 3, a stepped portion protruding from the inner circumferential wall surface is formed at the central portion of the lens barrel 18 in the axial direction. The stepped portion is a substantially annular portion when viewed along the axial direction, and both end surfaces of the stepped portion in the axial direction of the lens barrel 18 are mirrored along a direction perpendicular to the axial direction of the lens barrel 18. This is a plane extending from the inner circumferential wall surface of the cylinder 18.

A convex portion 180 protruding from the end surface on the image plane side is formed. The convex portions 180 are arranged at three-fold symmetrical positions with respect to the center of the stepped portion. The convex portion 180 includes a boss 181 that stands up from the step and a rib 182 that stands up from the step and connects the circumferential surface of the boss and the inner circumferential surface of the lens barrel 18 . The convex portion 180 is formed in a shape that fits into the groove 140 of the plastic lens 14 . The convex portion 180 corresponds to a second fitting portion.

Note that the lens barrel 18 is made of a material having a relatively smaller coefficient of linear expansion than the plastic lens 14.

(placement)
First, the arrangement of the lens on the objective side with respect to the above-mentioned step portion will be explained. A glass lens 13, a spacer 16, a glass lens 12, and a glass lens 11 are accommodated in this order from an opening on the objective side of the lens barrel 18. Next, the objective side retainer 10 covers the lens barrel 18 from the opening side of the lens barrel 18, and the female thread on the inner peripheral surface side of the objective side retainer 10 and the male thread on the objective side on the outer peripheral surface of the lens barrel 18 are screwed together. . In this way, the objective side retainer 10 advances toward the main body 210 along the axial direction of the lens barrel 18 and is fastened to the lens barrel 18.

As described above, the glass lens 13, the spacer 16, the glass lens 12, and the glass lens 11 are all appropriately structured to position each other so that their optical axes are aligned in the radial direction of the lens barrel 18. has. Therefore, in the radial direction, the lens 13, the glass lens 12, and the glass lens 11 are accommodated in the lens barrel 18 at a position where the optical axis is the axis of the lens barrel 18 on the object side with respect to the stepped portion.

Further, the glass lens 11 comes into contact with the aforementioned convex portion of the objective side retainer 10, and is pressed toward the main body 210 side as a result of the above-mentioned fastening. In this way, the objective-side retainer 10 presses the glass lenses 11 and 12, the spacer 16, and the glass lens 13 along the axial direction of the lens barrel 18 from the objective side. Therefore, the glass lens 13, the glass lens 12, and the glass lens 11 are attached to the lens barrel 18 at a position where the optical axis is the axis of the lens barrel 18 on the objective side than the stepped portion, and on the objective side than the stepped portion. Fixed.

Next, the arrangement of the lens on the image plane side of the stepped portion will be explained. The plastic lens 14 and the plastic lens 15 are accommodated in this order from the opening on the image plane side of the lens barrel 18 in the main body 210 . The plastic lens 14 comes into contact with the stepped portion at its peripheral edge, and each of the three convex portions 180 rising from the stepped portion fits into each of the three grooves 140 of the plastic lens 14 . Thereby, displacement of the plastic lens 14 in the radial direction is sufficiently suppressed.

Further, as described above, both the plastic lens 14 and the plastic lens 15 have an appropriate structure for positioning them so that their optical axes are the same in the radial direction of the lens barrel 18. . Therefore, in the radial direction, the plastic lens 14 and the plastic lens 15 are housed in the lens barrel 18 at a position where the optical axis is the axis of the lens barrel 18 on the image plane side than the step portion.

Note that each of the convex portions 180 is configured by a boss 181 that is arranged at a position away from the inner circumferential wall surface of the lens barrel 18 and a rib 182 that connects the boss 181 and the inner circumferential wall surface of the lens barrel 18. . Therefore, it has sufficient strength to determine the position of the lens 14 in the radial direction. In addition, since the boss 181 is connected to the lens barrel 18 by the rib 182, when manufacturing the resin lens barrel 18 by molding, molding defects of the boss 181 may occur due to gas remaining in the portion corresponding to the boss 181. occurrence is sufficiently suppressed.

The image side retainer 17 is inserted into the lens barrel 18 from an opening on the image side of the lens barrel 18 . The threaded portion 172 of the fastening portion 172 of the image side retainer 17 threads into a female thread on the inner peripheral surface of the lens barrel 18 . In this way, the image side retainer 17 advances toward the object side along the axial direction of the lens barrel 18 and is fastened to the lens barrel 18. As described above, the image side retainer 17 is made of resin, and the cylindrical portion 171 comes into contact with the plastic lens 15. Therefore, the plastic lenses 14 and 15 are urged in the axial direction of the lens barrel 18 by the elasticity of the image side retainer 17, and are fixed at a position within the lens barrel 18 with the axis of the lens barrel 18 as the optical axis. Ru.

The object side end surface of the image side retainer 17 has the protrusion 174 as described above, and the cylindrical portion 171 is in contact with the plastic lens 15 via the protrusion 174. Therefore, the cylindrical portion 171 that comes into contact with the plastic lens 15 has appropriate elasticity. Therefore, the image side retainer 17 presses the plastic lenses 14 and 15 with a more suitable pressing force.

Further, as described above, the lens barrel 18 is made of a material having a relatively smaller coefficient of linear expansion than the plastic lens 14. Therefore, if the groove 140 and the boss 181 have substantially the same dimensions at normal temperatures, the dimensions of the groove 140 will become larger at high temperatures. This prevents the groove 140 from being pressed by the expansion of the boss 181 at high temperatures, thereby preventing the lens 14 from deforming. Even in this case, the image side retainer 17 appropriately presses the plastic lenses 14 and 15 along the axial direction toward the stepped portion due to its elasticity. Therefore, even if a gap occurs between the boss 181 and the groove 140, the plastic lenses 14 and 15 are prevented from shifting in the radial direction.

In this way, the lens unit 100 uses the image side retainer 17 to fix the plastic lenses 14 and 15 to the lens barrel 18. Therefore, compared to the case where the plastic lens 14 is housed by press-fitting, it is possible to suppress the occurrence of distortion in the plastic lens and the lens barrel.

Moreover, the lens unit 100 can suitably suppress displacement of the plastic lens 14 in the radial direction by fitting the groove 140 and the convex portion 180. Further, since the image plane side retainer 17 appropriately presses the plastic lens in the axial direction, displacement of the plastic lens in the optical axis direction is suitably suppressed, and furthermore, displacement in the radial direction is also sufficiently suppressed. Therefore, the lens unit 100 can suitably suppress displacement of the plastic lens even if a change in temperature occurs within a temperature range that includes a relatively high temperature.

(effect)
As described above, the lens unit 100 can sufficiently suppress displacement of the plastic lens even if a temperature change occurs.

An example of an application of the lens unit 100 is a lens unit for vehicle-mounted sensing. In this application, it may be necessary to maintain performance even at -40°C on the low-temperature side and over 100°C on the high-temperature side. Furthermore, on the high temperature side, it may be required that there is no performance deterioration even in long-term storage tests at 120 to 125°C.

Conventionally, in consumer products with autofocus mechanisms, or viewing lens units that are often used with hundreds of thousands of pixels to 2 million pixels even in pan focus, lens deformation or lens displacement due to holding has occurred several times. Even if it was from micron to several tens of microns, it did not pose a problem in actual use.

However, in the above-mentioned vehicle-mounted sensing lens unit, there are cases where it is required to suppress the displacement to 1 micron or less.

Fiber-reinforced plastic lens barrels are often used as lens barrel materials that can withstand use in such environments. However, fiber-reinforced plastic lens barrels have anisotropy in the resin flow direction (MD) and in the direction perpendicular to the resin flow (TD). Therefore, as an example, if the linear expansion coefficient in the MD direction is 1.5×10 ⁻⁵ and the linear expansion coefficient in the TD direction is 3.0×10 ⁻⁵ , the displacement that is permissible as an in-vehicle sensing lens unit is The quantity may be exceeded.

More specifically, when the temperature changes from 20°C to -40°C, the displacement Δ at a distance of 10 mm in each direction is -0.008 mm in the MD direction and -0.016 mm in the TD direction. Become. Further, when the temperature changes from 20° C. to 120° C., Δ0.015 mm in the MD direction and Δ0.03 mm in the TD direction, respectively. As described above, even in fiber-reinforced plastic lens barrels that are said to be resistant to temperature changes, deformation may occur due to differences in fiber orientation.

The same applies to plastic lenses. For example, if the outer diameter is 10 mm and the coefficient of linear expansion is 7.0×10 ^-5 , when the temperature changes from 20°C to -40°C, the displacement _ΔL of the outer diameter of the plastic lens is -0. 042 mm, and when the temperature changes from 20°C to 120°C, _ΔL becomes 0.07mm.

Generally, in the case of a configuration in which a plastic lens is held by pressing in the radial direction, large play may occur between the outer diameter of the plastic lens and the inner diameter of the lens barrel due to thermal expansion and contraction, and lens shift movement may occur.

However, according to the lens unit 100 according to the present embodiment, the plastic lens can be used even in environments where there is a large difference in linear expansion coefficient between the plastic lens and the lens barrel, and where there is a large temperature difference such as -40°C to 120°C. Positioning and holding can be performed with high precision while suppressing deformation of the

In addition, even if the lens barrel is made of a material with a large difference in resin orientation and the lens barrel expands and contracts non-uniformly, the biasing of the image side retainer 17 can prevent the plastic lens from shifting its position. can.

Furthermore, the smaller the diameter of the boss of the second fitting part 180 and the width of the groove of the first fitting part 140 are, the more it is possible to suppress deformation due to dimensional changes due to temperature difference ΔT with respect to room temperature. can.

In this way, according to the lens unit 100 according to the present embodiment, even when thermal expansion and contraction occurs, highly accurate holding can be achieved without causing lens shift movement.

(Modified example of Embodiment 1)
The number of protrusions 174 that the cylindrical portion 171 of the image side retainer 17 has does not need to be six. The number of protrusions 174 may be determined depending on the elasticity imparted to the cylindrical portion 171, and the smaller the number, the stronger the elasticity can be. The number of protrusions 174 is preferably three or more, more preferably three, from the viewpoint of supporting the lens without wobbling.

The structure for positioning and fixing the plastic lens 14 in the radial direction of the lens barrel 18 is not limited to the groove 140 and the convex portion 180. For example, the lens barrel 18 may have a groove, and the plastic lens 14 may have a convex portion.

Furthermore, the lens unit 100 may include additional members as long as the effects of this embodiment can be obtained. For example, the lens unit 100 includes at least one of another lens, a spacer, and a light-shielding washer between the plastic lens 14 and the image side retainer 17 instead of or in addition to the plastic lens 15. It may also be configured to include an optical member. In such a configuration, other lenses, spacers, light shielding washers, etc. are also pressed in the optical axis direction by the image side retainer 17. Therefore, displacement of these optical members with respect to the optical axis can be suitably suppressed.

[Embodiment 2]
Other embodiments of the invention will be described below. For convenience of explanation, members having the same functions as the members described in the above embodiment are given the same reference numerals, and the description thereof will not be repeated.

FIG. 4 is a cross-sectional view showing the configuration of the lens unit 100a according to this embodiment. More specifically, FIG. 4 shows a state in which the first fitting part 140 and the second fitting part 180 are fitted, cut along a cutting plane along the axial direction that includes these fitting parts. FIG. FIG. 5 is an exploded perspective view showing each component of the lens unit 100a in FIG. 4 together with the main body 210 of the imaging device.

As shown in FIGS. 4 and 5, the lens unit 100a includes a first image surface side retainer 17a and a second image surface side retainer, instead of the image surface side retainer 17 included in the lens unit 100 according to the first embodiment. 17b. Further, a lens 19 is provided between the first image plane side retainer 17a and the second image plane side retainer 17a. The lens 19 is, for example, a glass lens, and the peripheral edge of the lens 19 fits into a step formed on the inner circumferential wall of the first image side retainer 17a, so that the lens 19 is aligned with the axis of the lens barrel 18 in the radial direction. It is housed in a position where the optical axis coincides with the optical axis. The other configuration of the abutting lens unit 100a is the same as that of the lens unit 100 according to the first embodiment.

Like the image side retainer 17 according to the first embodiment, the first image side retainer 17a accommodates the plastic lenses 14 and 15 in the lens barrel 18 by pressing them in the axial direction of the lens barrel 18. There is. The first image side retainer 17a is, for example, fastened to the lens barrel 18 by being screwed into the inner periphery of the lens barrel 18, similarly to the image side retainer 17 according to the first embodiment.

The second image side retainer 17b accommodates the lens 19 in the lens barrel 18 by pressing it in the axial direction of the lens barrel 18. Here, as shown in FIG. 4 as an example, the second image side retainer 17b is fastened to the first retainer 17a by screwing into the inner circumference of the first retainer 17a. By this fastening, the lens 19 is pressed and fixed along the axial direction toward the object side with appropriate strength and elasticity.

Further, as shown in FIGS. 4 and 5, the first image plane side retainer 17a includes a fastening portion 170 and a cylindrical portion 171a. Here, since the fastening portion 170 is the same as that in Embodiment 1, a description thereof will be omitted.

The cylindrical portion 171a includes a plurality of protrusions 174 that protrude along the axial direction from the tip edge 173 of the cylindrical portion 171a. These plurality of protrusions 174 contact the plastic lens 15, which is the lens on the image side of the plurality of plastic lenses, from the image side, and connect the plastic lens 15 and the plastic lens 14 in the optical axis direction. Press.

Further, the cylindrical portion 171a has a plurality of openings 175, as shown in FIG. Since the cylindrical portion 171a is provided with a plurality of openings in this manner, the elasticity of the first retainer 17a can be made more suitable, so that displacement of the plastic lens in the optical axis direction can be suppressed appropriately. can.

Further, as shown in FIG. 5, each of the plurality of openings 175 is provided at a position corresponding to each of the plurality of protrusions 174. In this way, by correlating the positions of the opening 175 and the protrusion 174, it is possible to press the plurality of plastic lenses more suitably.

In the example shown in FIG. 5, the number of openings 175 and the number of protrusions 174 are each three, but this does not limit the present embodiment, and the number may be other than three.

(Modification of Embodiment 2)
FIG. 6 is an exploded perspective view showing the first image plane side retainer 17c according to a modification of the present embodiment together with other components.

The lens unit 100a according to this modification includes a first image side retainer 17c shown in FIG. 6 instead of the first image side retainer 17a. The first image plane side retainer 17c shown in FIG. 6 includes a fastening portion 170 and a cylindrical portion 171c, as shown in FIG. Here, the cylindrical portion 171c does not have an opening 175, unlike the cylindrical portion 171a described above.

Even with such a configuration, displacement of the plastic lens in the optical axis direction can be suitably suppressed.

〔summary〕
The lens unit according to aspect 1 of the present invention includes one or more plastic lenses, a lens barrel that accommodates the one or more plastic lenses, and an outer edge of at least one of the one or more plastic lenses. one or more grooves (first fitting portions) to be fitted, and one or more convex portions (first fitting portions) disposed on the inner peripheral portion of the lens barrel and fitting to each of the one or more first fitting portions. a second fitting part), and a retainer (image side retainer) that presses one or more plastic lenses in the axial direction of the lens barrel and fixes them within the lens barrel.

According to this configuration, even if a temperature change occurs, displacement of the plastic lens can be suppressed.

In the lens unit according to aspect 2 of the present invention, in aspect 1, the retainer has elasticity and includes a fastening part fastened to the inner periphery of the lens barrel and a cylindrical part connected to the fastening part. It's okay.

According to this configuration, since the image plane side retainer has elasticity, it is possible to apply an appropriate pressing force to the plastic lens.

In the lens unit according to aspect 3 of the present invention, in aspect 2, the cylindrical portion may include a protrusion that protrudes along the axial direction from the distal end edge of the cylindrical portion.

According to this configuration, in addition to the effects of aspect 2, a more appropriate pressing force can be applied to the plastic lens.

In the lens unit according to aspect 4 of the present invention, in aspect 2 or 3, the cylindrical portion may further include a plurality of openings formed in the peripheral wall of the cylindrical portion.

According to this configuration, in addition to the effects of aspects 2 and 3, a more appropriate pressing force can be applied to the plastic lens.

The accessory adapter according to aspect 5 of the present invention is an optical member according to any one of aspects 1 to 4, which includes at least one of another lens, a spacer, and a light-shielding washer between the one or more plastic lenses and the retainer. may be provided.

This configuration also provides the same effects as the first aspect.

In the accessory adapter according to aspect 6 of the present invention, in any one of aspects 1 to 5, the first fitting part is a groove formed in the outer edge of the lens, and includes a groove extending in the optical axis direction. The second fitting portion may include a boss formed on the inner periphery of the lens barrel, the boss having a height direction in the optical axis direction.

According to this configuration, displacement of the plastic lens in the radial direction is suppressed by fitting the first fitting part and the second fitting part.

In the lens unit according to aspect 7 of the present invention, in aspect 6, the second fitting portion may include a rib that connects the boss and the inner circumferential surface of the lens barrel.

According to this configuration, the strength of the second fitting portion is improved, and displacement of the plastic lens in the radial direction can be more effectively suppressed.

In the accessory adapter according to aspect 8 of the present invention, in any one of aspects 1 to 7, the number of the first fitting portions and the number of second fitting portions may be three.

According to this configuration, displacement of the plastic lens in the radial direction can be effectively suppressed.

The present invention is not limited to the embodiments described above, and various modifications can be made within the scope of the claims. Embodiments obtained by appropriately combining technical means disclosed in different embodiments are also included in the technical scope of the present invention.

100, 100a Lens unit 10 Objective side retainer 11, 12, 13 Glass lens 14, 15 Plastic lens 140 Groove (first fitting part)
16 Spacer 17, 17a, 17b Image side retainer 170 Fastening portion 171, 171a, 171c Cylindrical portion 174 Projection 175 Opening 18 Lens barrel 19 Lens 180 Convex portion (second fitting portion)
181 Boss 182 Rib 210 Main body of imaging device

Claims (6)

one or more plastic lenses;
a lens barrel that accommodates the one or more plastic lenses;
one or more first fitting parts arranged on the outer edge of at least one of the one or more plastic lenses;
one or more second fitting parts arranged on the inner peripheral part of the lens barrel and fitting into each of the one or more first fitting parts;
a retainer that presses the one or more plastic lenses in the axial direction of the lens barrel and fixes them within the lens barrel;
Equipped with
The first fitting part is a groove formed in the outer edge of the lens, and includes a groove extending in the optical axis direction,
The second fitting part is a boss formed on the inner periphery of the lens barrel, and includes a boss whose height direction is in the optical axis direction,
fixing the lens by fitting the first fitting part and the second fitting part;
The second fitting portion includes a rib that connects the boss and the inner peripheral surface of the lens barrel.
A lens unit characterized by : The retainer is
It has elasticity,
a fastening portion fastened to the inner periphery of the lens barrel;
The lens unit according to claim 1, further comprising a cylindrical portion connected to the fastening portion. 3. The lens unit according to claim 2, wherein the cylindrical portion includes a protrusion that protrudes along the axial direction from a distal end edge of the cylindrical portion. 4. The lens unit according to claim 2, wherein the cylindrical portion further includes a plurality of openings formed in a peripheral wall of the cylindrical portion. Any one of claims 1 to 4, further comprising an optical member including at least one of another lens, a spacer, and a light-shielding washer, provided between the one or more plastic lenses and the retainer. The lens unit described in section. 6. The lens unit according to claim 1, wherein the number of the first fitting part and the second fitting part is three , respectively.

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