CN113433647A

CN113433647A - Lens unit

Info

Publication number: CN113433647A
Application number: CN202011305176.XA
Authority: CN
Inventors: 井上道夫
Original assignee: Tamron Co Ltd
Current assignee: Tamron Co Ltd
Priority date: 2020-03-05
Filing date: 2020-11-20
Publication date: 2021-09-24
Also published as: JP2021140043A; JP7446859B2

Abstract

The problem is to provide a lens unit capable of suppressing displacement of a plastic lens due to temperature change. The lens unit (100) is provided with plastic lenses (14, 15) and a lens barrel (18), wherein grooves (140) extending in the axial direction are formed in the outer edge portions of the plastic lenses (14, 15), and protrusions (180) fitted into the grooves (140) in the axial direction are formed in the inner edge portion of the lens barrel (18). The lens unit (100) is provided with a holder (17) for pressing and fixing the plastic lenses (14, 15) in the axial direction of the lens barrel (18) in the lens barrel (18).

Description

Lens unit

Technical Field

The present invention relates to a lens unit.

Background

In the related art, a technique for reducing lens looseness in a lens unit or a lens holding structure has been proposed. As such a technique, for example, a lens unit is known which has a resin barrel in which a plurality of lenses are assembled and screws the lenses with a holder (for example, see patent document 1).

As the above-described technique, a configuration is known in which a lens having an optical surface and a non-optical surface is provided, a plurality of guide portions are integrally provided on one surface of the non-optical surface and a surface of a lens barrel facing the non-optical surface, and an engagement portion for engaging with the guide portions is provided on the other surface (for example, see patent document 2).

As the above-described technique, a lens holder is known which includes an annular first lens pressing member that presses and fixes a peripheral portion of a first lens, and a second lens pressing member that extends in contact with an outer periphery of the first lens and presses and fixes an outer peripheral corner portion of a second lens in an optical axis direction and a radial direction (see, for example, patent document 3).

Documents of the prior art

Patent document

[ patent document 1] Japanese patent application laid-open No. 2019-179179

[ patent document 2] Japanese patent laid-open No. 2012 and 73543

[ patent document 2] Japanese patent application laid-open No. 2010-78920

Disclosure of Invention

Problems to be solved by the invention

The lens unit is subject to temperature changes according to the use environment and the like. 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, since the lens is assembled by press-fitting, the plastic lens may be deformed. Further, when expansion or contraction occurs in the direction in which the plastic lens is compressed due to a sharp temperature change, the deformation of the plastic lens further increases, so that it is difficult to suppress the deformation of the plastic lens below a predetermined value.

In the technique of patent document 2, since no force is applied in the optical axis direction, the position of the lens relative to the optical axis may vary.

In the technique of patent document 3, since the plastic lens is fixed by pressing the elastic member against the inner diameter of the lens barrel, the lens center may be displaced in accordance with expansion and contraction of the lens barrel.

An aspect of the present invention is to provide a lens unit capable of suppressing displacement of a plastic lens due to temperature change.

Means for solving the problems

To solve the above problem, a lens unit according to an aspect of the present invention includes: one or more plastic lenses; a lens barrel housing the one or more plastic lenses; one or more first fitting portions disposed at an outer peripheral portion of at least any one of the one or more plastic lenses; one or more second fitting portions arranged in an inner peripheral portion of the lens barrel and fitted to each of the one or more first fitting portions; and a holder that presses and fixes the one or more plastic lenses in the axial direction of the lens barrel.

Effects of the invention

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

Drawings

Fig. 1 is a sectional view showing a structure of a lens unit according to embodiment 1.

Fig. 2 is an exploded perspective view showing each configuration of the lens unit according to embodiment 1 together with the main body of the imaging device.

Fig. 3 is a rear view of the lens barrel of the lens unit according to embodiment 1, as viewed from the image plane side, together with the main body of the imaging device.

Fig. 4 is a sectional view showing the structure of the lens unit according to embodiment 2.

Fig. 5 is an exploded perspective view showing each configuration of the lens unit according to embodiment 2 together with the main body of the imaging device.

Fig. 6 is an exploded perspective view showing the first image plane side holder included in the lens unit according to the modification of embodiment 2, together with other configurations.

Description of reference numerals:

100. 100a lens unit

10 pairs of object side holding members

11. 12, 13 glass lens

14. 15 Plastic lens

140 groove (first embedding part)

16 spacer

17. 17a, 17b image plane side holder

170 screw fastening part

171. 171a, 171c cylinder

174 the protrusion

175 opening

18 lens barrel

19 lens

180 convex part (second embedded part)

181 convex platform

182 Ribs

210 main body of image pickup device

Detailed Description

Hereinafter, embodiments of the lens unit according to the present invention will be described. However, the lens unit to be described below is an embodiment of the lens unit according to the present invention, and the lens unit according to the present invention is not limited to the embodiment described below.

[ embodiment 1]

(Overall Structure)

First, the overall configuration of the lens unit 100 according to the present embodiment will be described with reference to fig. 1 and 2.

Fig. 1 is a sectional view showing a configuration of a lens unit 100 according to the present embodiment. More specifically, fig. 1 is a cross-sectional view taken along an axial cross-section including a fitting position of a first fitting portion 140 and a second fitting portion 180, which will be described later.

Fig. 2 is an exploded perspective view showing the respective components of the lens unit 100 in fig. 1 together with the main body 210 of the imaging apparatus.

As shown in fig. 1, the lens unit 100 includes a plurality of lenses, an object side holder 10, a spacer 16, an image plane side holder 17, and a lens barrel 18. The lens unit 100 is held by a main body 210 of the imaging apparatus.

(Structure of each part)

The lens unit 100 accommodates three glass lenses 11 to 13 and two

plastic lenses

14 and 15. The lenses each have a structure for determining a position in the radial direction. Examples of such structures for positioning include: the concave strips, the convex strips which are embedded with the concave strips, the holes and the convex plates which are embedded with the concave strips, one lens is provided with a convex surface with a specific shape and a concave surface which is adjacent to the convex surface and is matched with the specific shape of the other lens, and the outer peripheral wall part of the lens and the inner peripheral wall part of the lens barrel 18 which is abutted with the outer peripheral wall part of the lens. As described above, the plurality of lenses can be guided to the specific position in the radial direction when housed in the lens barrel 18.

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

The outer edge portion of the plastic lens 14 has a groove 140 extending in the thickness direction of the plastic lens 14. The groove 140 is provided at 3 on the outer peripheral portion of the plastic lens 14. In more detail, the groove 140 is provided at a position of cubic symmetry with the center of the plastic lens 14 as a symmetry center in a plan view. The groove 140 corresponds to the first fitting portion.

The object-side holder 10 is a substantially cylindrical body, and an internal thread is formed on an inner peripheral surface thereof. In addition, a convex portion that abuts against the glass lens is formed on the inner peripheral surface of the opening portion on the opposite side of the object side holder 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, 6) convex portions are formed on the edge of the spacer 16 on the opposite side to the glass lens 12.

The image surface side holder 17 is a substantially cylindrical body. The image surface side holder 17 is made of resin and has elasticity. The image surface side holder 17 includes a screw portion 170 positioned on the image surface side and a cylindrical portion 171 positioned on the opposite side.

The screw portion 170 has a screw portion 172 on an outer peripheral surface thereof and a female screw on an inner peripheral surface thereof. The threaded portion 172 is, for example, a male screw.

The cylindrical portion 171 is a cylindrical portion, and has a plurality of (for example, 6) protrusions 174 arranged at equal intervals in the circumferential direction on an end surface on the opposite side.

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

On an outer peripheral surface of the lens barrel 18 on the opposite side in the axial direction, an external thread is formed. The male screw is formed to be screwed with the female screw on the inner peripheral surface of the object side holder 10. Further, on the inner peripheral surface of the image surface side of the lens barrel 18 in the axial direction, a female screw is formed. The female screw is formed to be screwed into the screw portion 172 of the image surface side holder 17.

Here, fig. 3 is a rear view of the lens barrel of the lens unit according to embodiment 1 when 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 peripheral wall surface is formed at the center portion in the axial direction of the lens barrel 18. The step portion is a substantially annular portion when viewed in the axial direction, and both end surfaces of the step portion in the axial direction of the lens barrel 18 are planes extending from the inner circumferential wall surface of the lens barrel 18 in a direction orthogonal to the axial direction of the lens barrel 18.

On the end surface on the image surface side, a convex portion 180 protruding from the end surface is formed. The convex portion 180 is provided at a position three times symmetrical with respect to the center of the step portion. The convex portion 180 is constituted by a boss 181 rising from the step portion, and a rib 182 rising from the step portion and connecting a peripheral surface of the boss and an inner peripheral surface of the lens barrel 18. The convex portion 180 is formed in a shape to be fitted into the groove 140 of the plastic lens 14. The convex portion 180 corresponds to the second fitting portion.

In addition, the lens barrel 18 is made of a material having a relatively small coefficient of linear expansion compared to the plastic lens 14.

(configuration)

First, the arrangement of the lens on the object side from the stepped portion will be described. The glass lens 13, the spacer 16, the glass lens 12, and the glass lens 11 are housed in this order from the opening on the opposite side of the lens barrel 18. Next, the object side holder 10 covers the lens barrel 18 from the opening side of the lens barrel 18, and the female screw on the inner circumferential surface side of the object side holder 10 is screwed with the male screw on the object side on the outer circumferential surface of the lens barrel 18. Accordingly, the object side holder 10 is inserted into the main body 210 of the image pickup apparatus in 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 each appropriately have a configuration for positioning such that the positional relationship coincides with each other with the optical axis in the radial direction of the lens barrel 18. Therefore, the glass lens 13, the glass lens 12, and the glass lens 11 are accommodated in the lens barrel 18 on the object side of the stepped portion in the radial direction at a position where the axis of the lens barrel 18 is the optical axis.

The glass lens 11 is pressed against the main body 210 of the imaging apparatus by the aforementioned fastening in contact with the aforementioned convex portion of the object-side holder 10. Accordingly, the object side holder 10 presses the

glass lenses

11 and 12, the spacer 16, and the glass lens 13 from the object side in the axial direction of the lens barrel 18. Therefore, the glass lens 13, the glass lens 12, and the glass lens 11 are fixed to the lens barrel 18 at positions on the opposite side of the stepped portion with respect to the axis of the lens barrel 18 as the optical axis.

Next, the arrangement of the lens on the image plane side with respect to the step portion will be described. The plastic lens 14 and the plastic lens 15 are accommodated in this order from an opening on the image plane side of the lens barrel 18 in the main body 210 of the imaging apparatus. The plastic lens 14 abuts on the step portion at its peripheral edge portion, and each of three convex portions 180 rising from the step portion is fitted into each of three grooves 140 of the plastic lens 14. This sufficiently suppresses displacement of the plastic lens 14 in the radial direction.

Further, as described above, each of the

plastic lenses

14 and 15 suitably has a configuration for positioning such that the positional relationship coincides with each other with the optical axis in the radial direction of the lens barrel 18. Therefore, the

plastic lenses

14 and 15 are accommodated in the lens barrel 18 at positions closer to the image plane side than the stepped portion and having the axis of the lens barrel 18 as the optical axis in the radial direction.

Each of the convex portions 180 is composed of a boss 181 disposed at a position distant from the inner peripheral wall surface of the lens barrel 18, and a rib 182 connecting the boss 181 and the inner peripheral wall surface of the lens barrel 18. Therefore, it has an intensity sufficient to determine the position of the lens 14 in the radial direction. Further, since the boss 181 is connected to the lens barrel 18 by the rib 182, it is possible to sufficiently suppress the occurrence of molding failure of the boss 181 due to residual gas in the portion corresponding to the boss 181 when manufacturing the resin lens barrel 18 by molding.

The image surface side holder 17 is inserted into the lens barrel 18 from an opening on the image surface side of the lens barrel 18. The screwing portion 172 of the screwing portion 170 of the image surface side holder 17 is screwed with the internal thread of the inner peripheral surface of the lens barrel 18. Accordingly, the image plane side holder 17 enters the opposite side in the axial direction of the lens barrel 18, and is fastened to the lens barrel 18. As described above, the image plane side holder 17 is made of resin, and the cylindrical portion 171 abuts against the plastic lens 15. Therefore, the

plastic lenses

14 and 15 are forced in the axial direction of the lens barrel 18 by the elasticity of the image plane side holder 17, and the positions of the lens barrel 18 with the axis of the lens barrel 18 as the optical axis are fixed within the lens barrel 18.

The opposite-side end surface of the image plane side holder 17 has the projection 174 as described above, and the cylindrical portion 171 abuts against the plastic lens 15 via the projection 174. Therefore, the cylindrical portion 171 abutting the plastic lens 15 is appropriately elastic. Therefore, the image plane side holder 17 presses the

plastic lenses

14, 15 with a better pressing force.

Further, as described above, the lens barrel 18 is made of a material having a relatively small coefficient of linear expansion compared to the plastic lens 14. Therefore, if the groove 140 and the land 181 have substantially the same size at normal temperature, the size of the groove 140 increases at high temperature. Therefore, it is prevented that the groove 140 is pressed by the expansion of the boss 181 at a high temperature, and the lens 14 is deformed. At this time, the image plane side holder 17 also appropriately presses the

plastic lenses

14 and 15 toward the step portion in the axial direction due to its elasticity. Therefore, even if a gap is formed between the boss 181 and the groove 140, the

plastic lenses

14 and 15 can be prevented from being displaced in the radial direction.

In this way, the lens unit 100 fixes the

plastic lenses

14 and 15 to the lens barrel 18 by the image plane side holder 17. Therefore, as compared with the case of housing the plastic lens 14 by press-fitting, the plastic lens and the lens barrel can be suppressed from being twisted.

In the lens unit 100, the groove 140 and the projection 180 are fitted to each other, whereby the plastic lens 14 can be prevented from being displaced in the radial direction. Further, since the image plane side holder 17 appropriately presses the plastic lens in the axial direction, displacement of the plastic lens in the optical axis direction can be preferably suppressed, and further, displacement in the radial direction can be sufficiently suppressed. Therefore, in the lens unit 100, even if a temperature change occurs in a temperature range including a high temperature, displacement of the plastic lens can be suppressed preferably.

(Effect)

As described above, in the lens unit 100, even if a temperature change occurs, displacement of the plastic lens can be sufficiently suppressed.

As an example of the application of the lens unit 100, an in-vehicle sensing lens unit can be cited. In this application, there is a demand for use in panoramic focusing and performance maintenance even at a high temperature of less than-40 ℃ on the low temperature side and more than 100 ℃ on the high temperature side. Furthermore, there is a case where deterioration of performance is not expected even in a long-term storage test at 120 to 125 ℃ on the high temperature side.

Conventionally, in consumer products having an automatic focusing mechanism or an observation lens unit which can be used for around several hundred thousand to 200 thousand pixels in a large number even in panoramic focusing, no practical problem is caused even if lens strain or lens displacement due to holding is within several to several tens of micrometers.

However, in the above-described in-vehicle sensing lens unit, it is sometimes required to control the displacement to 1 μm or less.

As a lens barrel material that is durable to use under such an environment, a fiber-reinforced plastic lens barrel is often used. However, the fiber-reinforced plastic lens barrel has anisotropy in a resin flow direction (MD) and a direction perpendicular to the flow direction (TD). Therefore, for example, the linear expansion coefficient in the MD direction is 1.5 × 10^-5The linear expansion coefficient in the TD direction was 3.0X 10^-5In this case, the displacement amount allowed for the in-vehicle sensing lens unit may be exceeded.

In more detail, in the case where the temperature is varied between 20 ℃ and-40 ℃, the amount of displacement Δ at a portion distant by 10mm in each direction is-0.008 mm in the MD direction and-0.016 mm in the TD direction, respectively. When the temperature was varied from 20 ℃ to 120 ℃, the thickness was Δ 0.015mm in the MD and Δ 0.03mm in the TD, respectively. As described above, even a fiber-reinforced plastic lens barrel that is considered to be resistant to temperature changes may be deformed due to differences in fiber orientation.

In addition, the same applies to plastic lenses. For example, if the outer diameter is 10mm and the linear expansion coefficient is 7.0X 10^-5When the temperature is changed between 20 ℃ and-40 ℃, the displacement delta of the outer diameter of the plastic lens_LIs-0.042 mm, and has a temperature change of 20 ℃ to 120 ℃_LIs 0.07 mm.

In general, in the case of a structure in which a plastic lens is pressed and held in a radial direction, there is a possibility that a large play may be generated between an outer diameter of the plastic lens and an inner diameter of a lens barrel due to expansion and contraction with heat, and lens displacement movement can be generated.

However, according to the lens unit 100 of the present embodiment, even in an environment where the difference in linear expansion coefficient between the plastic lens and the lens barrel is large and there is a large temperature difference of-40 to 120 ℃, it is possible to perform positioning and holding with high accuracy while suppressing deformation of the plastic lens.

Further, even if the lens barrel expands and contracts unevenly, the plastic lens can be prevented from being displaced by the biasing force of the image surface side holder 17.

Further, as the diameter of the boss provided in the second fitting portion 180 and the width of the groove provided in the first fitting portion 140 are smaller, the strain due to the dimensional change caused by the temperature difference Δ T with respect to the room temperature can be effectively suppressed.

As described above, according to the lens unit 100 of the present embodiment, even when thermal expansion and contraction occur, lens displacement movement can be avoided, and high-precision holding can be achieved.

(modification of embodiment 1)

The number of the projections 174 of the cylindrical portion 171 of the image surface side holder 17 may be different from six. The number of the projections 174 may be determined according to the elasticity applied to the cylindrical portion 171, and the smaller the number, the stronger the elasticity can be made. The number of the projections 174 is preferably three or more, and more preferably three, from the viewpoint of supporting the lens so as not to loosen it.

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.

Further, the lens unit 100 may have further members within a range in which the effects of the present embodiment are obtained. For example, the lens unit 100 may be configured to include an optical member including at least one of a lens, a spacer, and a light shielding gasket, instead of the plastic lens 15, or together with the plastic lens 15, between the plastic lens 14 and the image plane side holder 17. In such a configuration, other lenses, spacers, light shielding washers, and the like are also pressed in the optical axis direction by the image plane side holder 17. Therefore, displacement of these optical members with respect to the optical axis can be preferably suppressed.

[ embodiment 2]

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

Fig. 4 is a cross-sectional view showing the structure of the lens unit 100a according to the present embodiment. More specifically, fig. 4 is a cross-sectional view taken along an axial cross-section including the fitting position of the first fitting portion 140 and the second fitting portion 180 in a state in which they are fitted. Fig. 5 is an exploded perspective view showing the respective components of the lens unit 100a in fig. 4 together with the main body 210 of the imaging apparatus.

As shown in fig. 4 and 5, the lens unit 100a includes a first image plane side holder 17a and a second image plane side holder 17b instead of the image plane side holder 17 included in the lens unit 100 according to embodiment 1. Further, a lens 19 is provided between the first image plane side holder 17a and the second image plane side holder 17 b. The lens 19 is, for example, a glass lens, and a peripheral edge portion of the lens 19 is accommodated in a position where an axis of the lens barrel 18 coincides with an optical axis in a radial direction by being fitted to a stepped portion formed on an inner peripheral wall of the first image plane side holder 17 a. The other configurations of the lens unit 100a in contact with each other are the same as those of the lens unit 100 according to embodiment 1.

The first image plane side holder 17a is configured to be accommodated in the lens barrel 18 by pressing the

plastic lenses

14 and 15 in the axial direction of the lens barrel 18, similarly to the image plane side holder 17 according to embodiment 1. For example, the first image plane side holder 17a is screwed to the lens barrel 18 by being screwed with the inner periphery of the lens barrel 18, as with the image plane side holder 17 according to embodiment 1.

The second image plane side holder 17b is housed in the lens barrel 18 by pressing the lens 19 in the axial direction of the lens barrel 18. Here, as shown in fig. 4, for example, the second image plane side holder 17b is screwed to the first holder 17a by being screwed to the inner periphery of the first holder 17 a. By this screwing, the lens 19 is pressed and fixed to the opposite object side with appropriate strength and elasticity in the axial direction.

As shown in fig. 4 and 5, the first image plane side holder 17a includes a screw portion 170 and a cylindrical portion 171 a. Here, the screw portion 170 is the same as embodiment 1, and therefore, the description thereof is omitted.

The cylindrical portion 171a includes a plurality of projections 174 projecting in the axial direction from a distal end edge 173 of the cylindrical portion 171 a. The plurality of projections 174 are brought into contact with the plastic lens 15, which is a lens on the image plane side, among the plurality of plastic lenses from the image plane side, and press the plastic lens 15 and the plastic lens 14 in the optical axis direction.

As shown in fig. 5, the cylindrical portion 171a has a plurality of openings 175. As described above, since the cylindrical portion 171a has the plurality of openings, the elasticity of the first holder 17a can be set to a more preferable elasticity, and thus displacement of the plastic lens in the optical axis direction can be suppressed more preferably.

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. As such, by establishing correspondence between the positions of the opening 175 and the protrusion 174, it is possible to preferably press the plurality of plastic lenses.

In the example shown in fig. 5, the number of the openings 175 and the number of the projections 174 are three, but this is not limitative to the present embodiment, and a number other than three may be provided.

(modification of embodiment 2)

Fig. 6 is an exploded perspective view showing the first image plane side holder 17c according to the modification of the present embodiment together with other configurations.

The lens unit 100a according to the present modification includes a first image plane side holder 17c shown in fig. 6 in place of the first image plane side holder 17 a. As shown in fig. 5, the first image plane side retainer 17c shown in fig. 6 includes a screw portion 170 and a cylindrical portion 171 c. Here, unlike the cylindrical portion 171a, the cylindrical portion 171c does not have the opening 175.

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

[ conclusion ]

A lens unit according to embodiment 1 of the present invention includes: one or more plastic lenses; a lens barrel housing the one or more plastic lenses; one or more grooves (first fitting portions) arranged at an outer edge portion of at least any one of the one or more plastic lenses; one or more convex portions (second fitting portions) arranged on an inner peripheral portion of the lens barrel and fitted to each of the one or more first fitting portions; and a holder (image plane side holder) that presses and fixes the one or more plastic lenses in the axial direction of the lens barrel inside 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 mode 2 of the present invention, in mode 1, the holder may have elasticity, and may include a screw portion that is screwed to an inner periphery of the lens barrel, and a tube portion that is connected to the screw portion.

According to this configuration, since the image surface side holder has elasticity, an appropriate pressing force can be applied to the plastic lens.

In the lens unit according to mode 3 of the present invention, in mode 2, the cylindrical portion may include a projection projecting in the axial direction from a distal end edge of the cylindrical portion.

With this configuration, in addition to the effect of the mode 2, an 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 a peripheral wall of the cylindrical portion.

With this configuration, in addition to the effects of the embodiments 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 may be configured such that, in any one of aspects 1 to 4, an optical member including at least one of another lens, a spacer, and a light shielding gasket is provided between the one or more plastic lenses and the holder.

The same effect as that of embodiment 1 can be obtained even with this configuration.

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

In the lens unit according to mode 7 of the present invention, in mode 6, the second fitting portion may include a rib connecting the boss and the inner peripheral surface of the lens barrel.

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

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

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

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

Claims

1. A lens unit having:

one or more plastic lenses;

a lens barrel, accommodating the one or more plastic lenses;

one or more first fitting parts arranged on the outer edge of at least any one of the one or more plastic lenses;

one or more second fitting portions disposed on the inner peripheral portion of the lens barrel to be fitted with each of the one or more first fitting portions; and

The holding member presses and fixes the one or more plastic lenses in the lens barrel along the axial direction of the lens barrel.

2. The lens unit of claim 1, wherein

The holder has elasticity, and includes a screwing portion screwed to the inner periphery of the lens barrel, and a cylindrical portion connected to the screwing portion.

3. The lens unit of claim 2, wherein

The cylindrical portion includes a protrusion protruding in the axial direction from a distal end edge of the cylindrical portion.

4. The lens unit according to claim 2 or 3, characterized in that,

The cylindrical portion further includes a plurality of openings formed on the peripheral wall of the cylindrical portion.

5. The lens unit according to any one of claims 1 to 4, wherein

An optical member including at least any one of another lens, a spacer, and a light shielding gasket is provided between the one or more plastic lenses and the holder.

6 . The lens unit according to claim 1 , wherein: 6 .

The first fitting portion includes a groove formed on the outer edge portion of the lens and extending in the direction of the optical axis,

The second fitting portion includes a boss formed on the inner circumference of the lens barrel and taking the optical axis direction as a height direction.

7. The lens unit of claim 6, wherein

The second fitting portion includes a rib connecting the boss and the inner peripheral surface of the lens barrel.

8. The lens unit according to any one of claims 1 to 7, wherein

The number of the first fitting portion and the number of the second fitting portion is three, respectively.