lens unit

Abstract

The problem is to provide a lens unit capable of suppressing displacement of a plastic lens due to temperature change. The solution is that the lens unit (100) has a plastic lens (14, 15) and a lens barrel (18), the outer edge portion of the plastic lens (14, 15) has a groove (140) extending in the axial direction, and the inner peripheral portion of the lens barrel (18) has a convex portion (180) embedded in the groove (140) in the axial direction. The lens unit (100) has a holding member (17) that presses and fixes the plastic lens (14, 15) in the lens barrel (18) in the axial direction of the lens barrel (18).

Description

TECHNICAL FIELD

[0001] The present application relates to a lens unit. BACKGROUND

[0002] In the past, a technique for reducing looseness of a lens in a lens unit or a lens holding structure has been proposed. As such a technique, for example, a lens unit having a resin barrel in which a plurality of lenses are assembled and a lens is screwed by a holding member is known (for example, refer to Patent Literature 1).

[0003] Further, as the above-described technique, a structure is known in which a lens having an optical surface and a non-optical surface is provided, and a plurality of guide portions are integrally provided on one of the non-optical surface and a surface of a barrel facing the non-optical surface, and an engagement portion for engaging the guide portions is provided on the other surface (for example, refer to Patent Literature 2).

[0004] Further, as the above-described technique, a lens holding body is known in which a circular ring-shaped first lens pressing member that presses and fixes a peripheral portion of a first lens, and a second lens pressing member that contacts an outer periphery of the first lens and extends in an optical axis direction and a radial direction to press and fix an outer peripheral corner portion of a second lens are provided (for example, refer to Patent Literature 3).

[0005] PRIOR ART DOCUMENTS

[0006] PATENT LITERATURE

[0007] [Patent Literature 1] Japanese Patent Application Laid-Open No. 2019-179179

[0008] [Patent Literature 2] Japanese Patent Application Laid-Open No. 2012-73543

[0009] [Patent Literature 2] Japanese Patent Application Laid-Open No. 2010-78920 SUMMARY

[0010] PROBLEMS TO BE SOLVED BY THE INVENTION

[0011] A lens unit is subjected to temperature changes in accordance with the use environment or the like. Even if such temperature changes occur, it is required to suppress displacement of a lens in the lens unit.

[0012] However, in the technique of Patent Literature 1, sometimes deformation of a plastic lens occurs due to assembly by press-fitting. Further, when expansion or contraction occurs in a direction in which the plastic lens is compressed due to a sharp temperature change, the deformation of the plastic lens further increases, and it is difficult to suppress the deformation of the plastic lens to be below a predetermined value.

[0013] Further, in the technique of Patent Literature 2, since there is no force acting in the optical axis direction, sometimes changes occur between the lens and the optical axis position.

[0014] Further, in the technology of Patent Literature 3, since the plastic lens is pressed and fixed to the inner diameter of the lens barrel with the elastic member, sometimes the lens center displacement is displaced in correspondence with the expansion and contraction of the lens barrel.

[0015] An aspect of the present application has an object to provide a lens unit capable of suppressing displacement of a plastic lens due to temperature change.

[0016] Means for solving the problem

[0017] To solve the above problem, a lens unit according to an aspect of the present application includes one or more plastic lenses, a lens barrel that houses the one or more plastic lenses, one or more first fitting portions provided at an outer edge portion of at least any one of the one or more plastic lenses, one or more second fitting portions provided at an inner peripheral portion of the lens barrel and fitted to each of the one or more first fitting portions, and a holding member that presses and fixes the one or more plastic lenses in the lens barrel in an axial direction of the lens barrel.

[0018] Effects of the Invention

[0019] According to an aspect of the present application, displacement of a plastic lens due to temperature change can be suppressed. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is a cross-sectional view showing the structure of the lens unit according to Embodiment 1.

[0021] Figure 2 is an exploded perspective view showing each structure included in the lens unit according to Embodiment 1 together with a main body of an image pickup apparatus.

[0022] Figure 3 is a back view when the lens barrel of the lens unit according to Embodiment 1 is observed together with the main body of the image pickup apparatus from an image plane side.

[0023] Figure 4 is a cross-sectional view showing the structure of the lens unit according to Embodiment 2.

[0024] Figure 5 is an exploded perspective view showing each structure included in the lens unit according to Embodiment 2 together with a main body of an image pickup apparatus.

[0025] Figure 6 is an exploded perspective view showing the first image plane side holding member included in the lens unit according to the modification of Embodiment 2 together with other structures.

[0026] Explanation of Reference Numerals:

[0027] 100, 100a lens unit

[0028] 10 object side holder

[0029] 11, 12, 13 glass lens

[0030] 14, 15 plastic lens

[0031] 140 groove (first fitting portion)

[0032] 16 spacer

[0033] 17, 17a, 17b image side holder

[0034] 170 screw portion

[0035] 171, 171a, 171c cylindrical portion

[0036] 174 protrusion

[0037] 175 opening

[0038] 18 lens barrel

[0039] 19 lens

[0040] 180 convex portion (second fitting portion)

[0041] 181 boss

[0042] 182 rib

[0043] 210 body of camera DETAILED DESCRIPTION

[0044] Hereinafter, an embodiment of the lens unit according to the present application will be described. However, the lens unit to be described below is one mode of the lens unit according to the present application, and the lens unit according to the present application is not limited to the mode described below.

[0045] [Embodiment 1]

[0046] (Overall structure)

[0047] First, the overall structure of the lens unit 100 according to the present embodiment will be described with reference to Figure 1 and Figure 2 .

[0048] Figure 1 is a cross-sectional view showing the structure of the lens unit 100 according to the present embodiment. More specifically, Figure 1 is a cross-sectional view showing a cross section taken along an axial direction at a fitting position including the first fitting portion 140 and the second fitting portion 180 to be described later.

[0049] Figure 2 is shown in an exploded perspective view together with the main body 210 of the imaging device. Figure 1

[0050] As shown in FIG. 1, the lens unit 100 includes a plurality of lenses, an object side holding member 10, a spacer 16, an image surface side holding member 17, and a lens barrel 18. The lens unit 100 is configured to be held by the main body 210 of the imaging device. Figure 1 (Structure of each part)

[0051] The plurality of lenses housed in the lens unit 100 are three glass lenses 11 to 13 and two plastic lenses 14 and 15. Each of the lenses has a structure for determining a position in the radial direction. Examples of such a structure for positioning include a concave groove and a convex groove fitted thereto, a hole and a convex boss fitted thereto, one lens having a convex surface of a specific shape and another lens adjacent thereto having a concave surface matching the specific shape, and an outer peripheral wall portion of a lens and an inner peripheral wall portion of the lens barrel 18 abutting thereto. In this way, the plurality of lenses are configured to be guided to a specific position determined in the radial direction when housed in the lens barrel 18.

[0052] In addition, in the present embodiment, two plastic lenses are shown, but the number of plastic lenses is not limited thereto, and the number of plastic lenses can be one or more than three.

[0053] 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 three places on the outer edge portion of the plastic lens 14. In more detail, the groove 140 is provided at positions of three-fold symmetry with the center of the plastic lens 14 in plan view as a center of symmetry. The groove 140 corresponds to a first fitting portion.

[0054] The object side holding member 10 is a substantially cylindrical body having an inner thread formed on the inner peripheral surface thereof. In addition, a convex portion abutting against the glass lens is formed on the inner peripheral surface of the opening portion on the object side of the object side holding member 10.

[0055] The spacer 16 is a spacer sandwiched 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 end edge on the object side of the spacer 16 abutting against the glass lens 12.

[0056]

[0057] ​​The image plane side holder 17 is a substantially cylindrical body. In addition, the image plane side holder 17 is composed of resin, and has elasticity. The image plane side holder 17 has a screwing portion 170 on the image plane side, and a cylindrical portion 171 on the object side.

[0058] The screwing portion 170 has a screwing portion 172 on the outer peripheral surface, and an internal thread on the inner peripheral surface. The screwing portion 172 is, for example, an external thread.

[0059] The cylindrical portion 171 is a cylindrical portion having a plurality of (for example, six) protrusions 174 arranged at equal intervals in the circumferential direction on the end surface on the object side.

[0060] The lens barrel 18 is a substantially cylindrical member made of resin, and has opening portions on both the object side and the image plane side. The lens barrel 18 can be made of, for example, fiber-reinforced resin, but this is not a limitation on the present embodiment.

[0061] An external thread is formed on the outer peripheral surface of the object side of the lens barrel 18 in the axial direction. The external thread is formed so as to be screwed with the internal thread of the inner peripheral surface of the object side holder 10. In addition, an internal thread is formed on the inner peripheral surface of the image plane side of the lens barrel 18 in the axial direction. The internal thread is formed so as to be screwed with the screwing portion 172 of the image plane side holder 17.

[0062] Here, Figure 3 is a back view when the lens barrel of the lens unit according to Embodiment 1 is observed together with the main body of the imaging device from the image plane side. As shown in Figure 3 A stepped portion protruding from the inner peripheral wall surface is formed in the central portion in the axial direction of the lens barrel 18. The stepped portion is a substantially annular portion when viewed in the axial direction, and both end surfaces of the stepped portion in the axial direction of the lens barrel 18 are planes extending from the inner peripheral wall surface of the lens barrel 18 in a direction orthogonal to the axial direction of the lens barrel 18.

[0063] A convex portion 180 protruding from the end surface on the image plane side is formed. The convex portion 180 is provided at a position of three-fold symmetry with the center of the stepped portion as a center of symmetry. The convex portion 180 is composed of a boss 181 rising from the stepped portion, and a rib 182 rising from the stepped portion and connecting the peripheral surface of the boss and the inner peripheral surface of the lens barrel 18. The convex portion 180 is formed in a shape so as to be fitted with the groove 140 of the plastic lens 14. The convex portion 180 corresponds to the second fitting portion.

[0064] In addition, the lens barrel 18 is composed of a material having a relatively small coefficient of linear expansion compared to the plastic lens 14.

[0065] (Configuration)

[0066] First, the arrangement of the lenses closer to the object side than the aforementioned step portion will be described. From the opening of the lens barrel 18 on the object side, the glass lens 13, the spacer 16, the glass lens 12, and the glass lens 11 are housed in this order. Next, the object side holder 10 covers the lens barrel 18 from the opening side of the lens barrel 18, and the internal thread on the inner peripheral surface side of the object side holder 10 is screwed with the external thread on the outer peripheral surface on the object side of the lens barrel 18. Thus, the object side holder 10 enters the main body 210 side of the imaging device in the axial direction of the lens barrel 18, and is fastened to the lens barrel 18.

[0067] 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 in which the positional relationship is such that the optical axes coincide with each other in the radial direction of the lens barrel 18. Therefore, in this radial direction, the glass lens 13, the glass lens 12, and the glass lens 11 are housed in the lens barrel 18 closer to the object side than the aforementioned step portion at a position at which the axis of the lens barrel 18 is the optical axis.

[0068] Further, the glass lens 11 abuts against the aforementioned convex portion of the object side holder 10, and is pressed toward the main body 210 side of the imaging device by the aforementioned fastening. Thus, the object side holder 10 presses the glass lens 11, the glass lens 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 closer to the object side than the aforementioned step portion at a position at which the axis of the lens barrel 18 is the optical axis.

[0069] Next, the arrangement of the lenses closer to the image plane side than the step portion will be described. From the opening of the lens barrel 18 on the image plane side in the main body 210 of the imaging device, the plastic lens 14 and the plastic lens 15 are housed in this order. The plastic lens 14 abuts against the step portion at its peripheral portion, and each of the three convex portions 180 rising from the step portion is fitted into each of the three grooves 140 of the plastic lens 14. Thus, the displacement of the plastic lens 14 in the radial direction is sufficiently suppressed.

[0070] Further, as described above, the plastic lens 14 and the plastic lens 15 each appropriately have a configuration for positioning in which the positional relationship is such that the optical axes coincide with each other in the radial direction of the lens barrel 18. Therefore, in this radial direction, the plastic lens 14 and the plastic lens 15 are housed in the lens barrel 18 closer to the image plane side than the aforementioned step portion at a position at which the axis of the lens barrel 18 is the optical axis.

[0071] Further, the protrusions 180 are each composed of a boss 181 disposed at a position away 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, the strength is 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, when the resin lens barrel 18 is manufactured by molding, the molding failure of the boss 181 due to the gas remaining in the portion corresponding to the boss 181 can be sufficiently suppressed.

[0072] The image plane side holder 17 is inserted into the lens barrel 18 from the opening of the image plane side of the lens barrel 18. The screwing portion 172 in the screwing portion 170 of the image plane side holder 17 is screwed with the internal thread of the inner peripheral surface of the lens barrel 18. Thus, the image plane side holder 17 enters 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 plane side holder 17 is made of resin, and the barrel portion 171 abuts against the plastic lens 15. Therefore, the plastic lens 14 and the plastic lens 15 are stressed in the axial direction of the lens barrel 18 by the elasticity of the image plane side holder 17, and are fixed at the position in the lens barrel 18 with the axis of the lens barrel 18 as the optical axis.

[0073] The end surface of the object side of the image plane side holder 17 has the protrusion 174 as described above, and the barrel portion 171 abuts against the plastic lens 15 through the protrusion 174. Therefore, the barrel portion 171 abutting against the plastic lens 15 is elastically deformed moderately. Thus, the image plane side holder 17 presses the plastic lenses 14 and 15 with a more appropriate pressing force.

[0074] Further, the lens barrel 18 is made of a material having a relatively small linear expansion coefficient compared to the plastic lens 14 as described above. Therefore, if the groove 140 and the boss 181 are substantially the same size at normal temperature, the size of the groove 140 becomes larger at high temperature. Thus, the deformation of the lens 14 due to the pressing of the groove 140 by the expansion of the boss 181 at high temperature is prevented. At this time, the image plane side holder 17 also appropriately presses the plastic lenses 14 and 15 in the axial direction toward the step portion by the elasticity thereof. Therefore, even if a gap is generated between the boss 181 and the groove 140, the shift of the plastic lenses 14 and 15 in the position in the radial direction is prevented.

[0075] 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, compared to the case where the plastic lenses 14 are housed by press-fitting, the distortion of the plastic lenses and the lens barrel can be suppressed.

[0076] Further, in the lens unit 100, by the fitting of the groove 140 and the protrusion 180, displacement of the plastic lens 14 in the radial direction can be preferably suppressed. Further, since the image plane side holder 17 moderately 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 is also 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 preferably suppressed.

[0077] (EFFECT)

[0078] As described above, in the lens unit 100, displacement of the plastic lens can be sufficiently suppressed even if a temperature change occurs.

[0079] As an example of the use of the lens unit 100, a vehicle-mounted sensing lens unit can be cited. In this use, there is a case where it is required to use in a panoramic focus and maintain performance even at a high temperature of more than 100°C on the high temperature side and less than -40°C on the low temperature side. Further, it is sometimes required that there is no performance degradation even in a long-term storage test at 120 to 125°C on the high temperature side.

[0080] Conventionally, in a consumer product having an automatic focusing mechanism, or in an observation lens unit in which a panoramic focus can be used even at several ten to 200 million pixels or so, even if the lens deformation or the lens displacement due to the holding is within several to several tens of micrometers, there is no problem in actual use.

[0081] However, in the above-described vehicle-mounted sensing lens unit, there is a case where it is required to control these displacements to be less than 1 micrometer.

[0082] As a material for a lens barrel that is resistant to use in such an environment, a fiber-reinforced plastic lens barrel is mostly used. However, the fiber-reinforced plastic lens barrel has anisotropy of a resin in a flow direction (MD) and a direction perpendicular to the flow (TD). Therefore, as an example, in a case where the linear expansion coefficient in the MD direction is 1.5 x 10 -5 and the linear expansion coefficient in the TD direction is 3.0 x 10 -5 , sometimes, the displacement amount exceeds the allowable displacement amount for a vehicle-mounted sensing lens unit.

[0083] More specifically, the displacement amount Δ at a portion 10 mm away in each direction was -0.008 mm in the MD direction and -0.016 mm in the TD direction when the temperature was varied between 20°C and -40°C. In addition, the displacement amount Δ was 0.015 mm in the MD direction and 0.03 mm in the TD direction when the temperature was varied between 20°C and 120°C. In this way, even a fiber-reinforced plastic lens barrel, which is considered to be resistant to temperature changes, can be deformed due to differences in fiber orientation.

[0084] Furthermore, the same applies to a plastic lens. For example, if the outer diameter is 10 mm and the linear expansion coefficient is 7.0 x 10 -5 , the displacement amount Δ of the outer diameter of the plastic lens when the temperature is varied between 20°C and -40°C is -0.042 mm, and the displacement amount Δ when the temperature is varied from 20°C to 120°C is 0.07 mm. L L

[0085] Generally, in the case of a structure that presses and holds a plastic lens in the radial direction, a large play can 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 displacement movement can occur.

[0086] However, according to the lens barrel unit 100 according to the present embodiment, even in an environment in which the linear expansion coefficients of the plastic lens and the lens barrel differ greatly and there is a large temperature difference of -40°C to 120°C, positioning and holding can be performed with high precision while suppressing deformation of the plastic lens.

[0087] Furthermore, as a material for which the resin orientation difference of the lens barrel material is large, even if the lens barrel expands and contracts unevenly, the position of the plastic lens can be prevented from shifting by the urging force at the image plane side holder 17.

[0088] Furthermore, the smaller the diameter of the boss of the second fitting portion 180 and the width of the groove of the first fitting portion 140, the more effectively deformation caused by dimensional changes due to a temperature difference ΔT from normal temperature can be suppressed.

[0089] In this way, according to the lens barrel unit 100 according to the present embodiment, even in the case of thermal expansion and contraction, lens displacement movement can be avoided, and high-precision holding can be achieved.

[0090] (Modified Example of Embodiment 1)

[0091] ​​The number of protrusions 174 in the cylindrical portion 171 of the image-side retainer 17 may not be six. The number of protrusions 174 can be determined based on the elasticity applied to the cylindrical portion 171; the fewer the protrusions, the stronger the elasticity. From the viewpoint of supporting the lens and preventing it from loosening, the number of protrusions 174 is preferably three or more, and more preferably three.

[0092] 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 protrusion 180. For example, the lens barrel 18 may have a groove and the plastic lens 14 may have a protrusion.

[0093] Furthermore, the lens unit 100 may also have further components within the scope of achieving the effects of this embodiment. For example, the lens unit 100 may also be configured to include, between the plastic lens 14 and the image-side retainer 17, an optical component that replaces the plastic lens 15, or includes, along with the plastic lens 15, at least one of other lenses, spacers, and light-shielding gaskets. In such a structure, the other lenses, spacers, and light-shielding gaskets are also pressed towards the optical axis by the image-side retainer 17. Therefore, displacement of these optical components relative to the optical axis can be better suppressed.

[0094] [Implementation Method 2]

[0095] Other embodiments of the present invention will be described below. Furthermore, for ease of explanation, components having the same function as those described in the above embodiments will be given the same reference numerals, and their descriptions will not be repeated.

[0096] Figure 4 This is a cross-sectional view showing the structure of the lens unit 100a according to this embodiment. More specifically, Figure 4 It is a cross-sectional view obtained by cutting along an axial section plane, including their fitting positions, when the first fitting part 140 and the second fitting part 180 are fitted together. Figure 5 It is Figure 4 An exploded perspective view showing the various structures of the lens unit 100a together with the main body 210 of the imaging device.

[0097] like Figure 4 , Figure 5As shown, the lens unit 100a is provided with a first image plane side holder 17a and a second image plane side holder 17b instead of the image plane side holder 17 provided in the lens unit 100 related to Embodiment 1. Further, between the first image plane side holder 17a and the second image plane side holder 17b, the lens 19 is provided. The lens 19 is, for example, a glass lens, and the peripheral edge portion of the lens 19 is housed in the position where the axis of the lens barrel 18 and the optical axis coincide in the radial direction by fitting into the stepped portion formed on the inner peripheral wall of the first image plane side holder 17a. The other structures of the lens unit 100a abutting against each other are the same as those of the lens unit 100 related to Embodiment 1.

[0098] The first image plane side holder 17a, like the image plane side holder 17 related to Embodiment 1, houses the plastic lenses 14, 15 in the lens barrel 18 by pressing them in the axial direction of the lens barrel 18. As an example, like the image plane side holder 17 related to Embodiment 1, the first image plane side holder 17a is screwed onto the lens barrel 18 by screwing into the inner periphery of the lens barrel 18.

[0099] 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 an example Figure 4 As shown, the second image plane side holder 17b is screwed onto the first holder 17a by screwing into the inner periphery of the first holder 17a. By this screwing, the lens 19 is pressed and fixed in the axial direction to the object side with a moderate strength and elasticity.

[0100] In addition, as shown in Figure 4 and Figure 5 As shown, the first image plane side holder 17a is provided with a screwing portion 170 and a barrel portion 171a. Here, the screwing portion 170 is the same as that of Embodiment 1, and thus the description thereof is omitted.

[0101] The barrel portion 171a is provided with a plurality of protrusions 174 protruding in the axial direction from the top edge 173 of the barrel portion 171a. These plurality of protrusions 174 abut against the plastic lens 15, which is the 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.

[0102] Further, as shown in Figure 5 As shown, the barrel portion 171a has a plurality of openings 175. Thus, since the barrel portion 171a is provided with a plurality of openings, the elasticity of the first holder 17a can be set to be more optimal, and thus the displacement of the plastic lenses in the optical axis direction can be more optimally suppressed.

[0103] Further, as shown in Figure 5As shown, 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 establishing a correspondence between the positions of the openings 175 and the protrusions 174, the plurality of plastic lenses can be pressed more favorably.

[0104] In addition, in Figure 5 In the example shown, the number of openings 175 and protrusions 174 is three, but this is not limiting to the present embodiment, and the number can be other than three.

[0105] (Modified example of Embodiment 2)

[0106] Figure 6 is an exploded perspective view showing the first image plane side holder 17c of the modified example of the present embodiment together with other structures.

[0107] The lens unit 100a of the modified example has Figure 6 the first image plane side holder 17c shown. As Figure 5 shown, Figure 6 the first image plane side holder 17c shown has a screwing portion 170 and a barrel portion 171c. Here, the barrel portion 171c is different from the barrel portion 171a described above, and does not form an opening 175.

[0108] Even with such a structure, displacement of the plastic lenses in the optical axis direction can be favorably suppressed.

[0109] [Summary]

[0110] The lens unit according to Mode 1 of the present invention has one or more plastic lenses; a lens barrel that houses the one or more plastic lenses; one or more grooves (first engagement portions) disposed at an outer edge portion of at least any one of the one or more plastic lenses; one or more convex portions (second engagement portions) disposed at an inner peripheral portion of the lens barrel and engaged with each of the one or more first engagement portions; and a holder (image plane side holder) that presses and fixes the one or more plastic lenses in the lens barrel in an axial direction of the lens barrel.

[0111] According to this structure, even if a temperature change occurs, displacement of the plastic lenses can be suppressed.

[0112] The lens unit according to Mode 2 of the present invention can also be in Mode 1, in which the holder has elasticity, and has a screwing portion that is screwed to an inner periphery of the lens barrel, and a barrel portion that is connected to the screwing portion.

[0113] According to this structure, because the image plane side holder has elasticity, an appropriate pressing force can be applied to the plastic lenses.

[0114] The lens unit according to Mode 3 of the present application can also be used in Mode 2, in which the barrel portion has a protrusion protruding in the axial direction from the top edge of the barrel portion.

[0115] According to this structure, in addition to the effects of Mode 2, appropriate pressing force can be applied to the plastic lens.

[0116] The lens unit according to Mode 4 of the present application can also be used in Mode 2 or 3, in which the barrel portion further has a plurality of openings formed in the peripheral wall of the barrel portion.

[0117] According to this structure, in addition to the effects of Modes 2 and 3, more appropriate pressing force can be applied to the plastic lens.

[0118] The accessory adapter according to Mode 5 of the present application can also be used in any one of Modes 1 to 4, in which between the one or more plastic lenses and the holding member, there is provided an optical member including at least any one of another lens, a spacer, and a light-blocking gasket.

[0119] Even according to this structure, the same effects as in Mode 1 can be obtained.

[0120] The accessory adapter according to Mode 6 of the present application can also be used in any one of Modes 1 to 5, in which the first fitting portion includes a groove formed in the outer edge portion of the lens and extending in the optical axis direction, and the second fitting portion includes a boss formed in the inner periphery of the lens barrel and having the optical axis direction as the height direction.

[0121] According to this structure, by fitting the first fitting portion and the second fitting portion, displacement of the plastic lens in the radial direction is suppressed.

[0122] The lens unit according to Mode 7 of the present application can also be used in Mode 6, in which the second fitting portion includes a rib connecting the boss and the inner peripheral surface of the lens barrel.

[0123] According to this structure, the strength of the second fitting portion can be improved, and displacement of the plastic lens in the radial direction can be more effectively suppressed.

[0124] The accessory adapter according to Mode 8 of the present application can also be used in any one of Modes 1 to 7, in which the number of the first fitting portions and the second fitting portions is three, respectively.

[0125] According to this structure, displacement of the plastic lens in the radial direction can be effectively suppressed.

[0126] The present application is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims. Embodiments obtained by appropriately combining the technical solutions disclosed in the respective embodiments are also included in the technical scope of the present application.

Claims

1. A vehicle-mounted lens unit comprising: one or more plastic lenses; a lens barrel that houses the one or more plastic lenses; one or more first fitting portions provided at an outer edge portion of at least any one of the one or more plastic lenses; one or more second fitting portions provided at an inner peripheral portion of the lens barrel, each of which is fitted with each of the one or more first fitting portions; and a holding member that presses and fixes the one or more plastic lenses in the lens barrel in an axial direction of the lens barrel, wherein the first fitting portion includes a groove formed at the outer edge portion of the lens and extending in an optical axis direction, the second fitting portion includes a boss formed at the inner peripheral portion of the lens barrel and having the optical axis direction as a height direction, the lens is fixed in a radial direction of the lens barrel by fitting of the first fitting portion and the second fitting portion, and the lens barrel is made of a resin, and is made of a material having a relatively small coefficient of linear expansion compared to the one or more plastic lenses.

2. The vehicle-mounted lens unit according to claim 1, wherein the holding member has elasticity, and includes a screwing portion that is screwed to the inner peripheral portion of the lens barrel, and a barrel portion that is connected to the screwing portion.

3. The vehicle-mounted lens unit according to claim 2, wherein the barrel portion includes a protrusion that protrudes in the axial direction from a top edge of the barrel portion.

4. The vehicle-mounted lens unit according to claim 2 or 3, wherein the barrel portion further includes a plurality of openings formed in a peripheral wall of the barrel portion.

5. The vehicle-mounted lens unit according to claim 1, 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 holding member.

6. The vehicle-mounted lens unit according to claim 1, wherein the second fitting portion includes a rib that connects the boss and an inner peripheral surface of the lens barrel.

7. The vehicle-mounted lens unit according to claim 1, wherein the number of the first fitting portions and the number of the second fitting portions are each three. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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