JP7688073B2 - Lens units and camera modules - Google Patents

Description

The present invention particularly relates to a lens unit and a camera module that constitute an on-board camera mounted on a vehicle such as an automobile.

In recent years, automobiles have been equipped with on-board cameras to assist with parking and prevent collisions through image recognition, and there are also attempts to apply this to autonomous driving. Camera modules such as on-board cameras generally include a lens unit that includes a lens group consisting of multiple lenses arranged along an optical axis, a barrel that houses and holds the lens group, and an aperture member that is placed between at least one of the lenses in the lens group (see, for example, Patent Document 1).

In a lens unit, generally, as shown in FIG. 9, multiple lenses 101, 102, 103, 104, and 105 constituting a lens group L are assembled in the inner storage space S of the lens barrel 123 so as to be stacked in order from the image side (lower side in FIG. 9) to the object side (upper side in FIG. 9). In this case, generally, these lenses 101, 102, 103, 104, and 105 are directly fitted (or lightly pressed) into the inner surface of the lens barrel 123 by utilizing the inner surface shape of the lens barrel 123 so that the lenses do not shift due to vibration, impact, etc., causing deterioration of resolution performance or misalignment of the optical axis.

JP 2013-231993 A

However, when the lens is fitted inside the lens barrel in direct contact with the lens barrel like this, if there is a difference in the linear expansion coefficient (thermal expansion coefficient) between the lens barrel and the lens, the lens may receive compressive stress from the lens barrel due to thermal expansion of the lens inside the lens barrel, especially in a high temperature environment, and the surface shape of the lens may be deformed.

For this reason, it is possible to consider providing a gap between the lens and the lens barrel in order to prevent such lens deformation, but in that case, there is a risk that the lens will become loose, causing degradation in resolution performance and misalignment of the optical axis, leading to a deterioration in optical performance.

The present invention has been made in consideration of the above circumstances, and aims to provide a lens unit and camera module that can accurately center and position the lens within the lens barrel while suppressing the compressive stress that the lens receives from the lens barrel due to its thermal expansion, and can regulate the decentering of the lens relative to the optical axis.

In order to solve the above-mentioned problems, the present invention provides a lens unit including a cylindrical lens barrel that defines an internal storage space for storing and holding lenses, and a lens group that is incorporated in the internal storage space of the lens barrel and that is formed by arranging a plurality of lenses along an optical axis,
a lens support portion that supports the lens in a fitted state;
the lens support portion is formed by at least the lens barrel, and has a non-contact area where the lens barrel and the lens do not come into contact with each other, and a positioning support area that supports the lens with respect to the lens barrel and positions the lens concentrically with the optical axis,
The positioning support region is characterized in that its thickness in the radial direction is set to be thinner than that of the non-contact region.

According to the above-mentioned configuration of the present invention, the lens support part that supports the lens in a fitted state has a non-contact area where the lens barrel does not come into contact with the lens, and a positioning support area that supports the lens relative to the lens barrel and positions it concentrically with the optical axis, and the thickness along the radial direction of the positioning support area is set to be thinner than that of the non-contact area. In other words, while ensuring a non-contact area where the lens does not come into contact with the lens barrel, the lens support part is set to have a thin thickness in the positioning support area where the lens may directly or indirectly receive compressive stress from the lens barrel during thermal expansion of the lens. This effectively releases the thermal expansion of the lens not only in the non-contact area but also in the positioning support area, alleviating the compressive stress acting on the lens and suppressing deformation of the lens surface shape due to the compressive stress. In addition, while the lens support part has a non-contact area where the lens barrel does not come into contact with the lens, the positioning support area can reliably support the lens relative to the lens barrel and position it concentrically with the optical axis, so there is no risk of the lens rattling, causing deterioration in resolution performance or misalignment of the optical axis, which could lead to deterioration in optical performance.

In the above-mentioned configuration of the present invention, the lens support portion may be formed by a lens barrel and an annular interposing member that is interposed between the outer peripheral side surface of the lens and the inner surface of the lens barrel to position the lens concentrically with the optical axis without contacting the lens barrel. In this case, the interposing member may have a lens fitting portion that fits with the lens without contacting the lens barrel to form a positioning support area, and a lens barrel fitting portion that fits with the lens barrel without contacting the lens to form a non-contact area together with the lens barrel.

In this way, if an annular insert member having a lens fitting portion that fits with the lens without contacting the lens barrel and a lens barrel fitting portion that fits with the lens barrel without contacting the lens is inserted between the outer peripheral side surface of the lens and the inner surface of the lens barrel, and the lens is positioned concentrically with the optical axis without contacting the lens barrel by this insert member, that is, if the lens is not directly contacted and fitted with the lens barrel over the entire circumference inside the lens barrel, even if there is a difference in the linear expansion coefficient (thermal expansion coefficient) between the lens barrel and the lens, the lens will not be affected by the lens barrel. In other words, even if the lens inside the lens barrel expands thermally in a high-temperature environment, the lens will not be subjected to compressive stress from the lens barrel, and therefore the eccentricity of the lens can be regulated and the deformation of the lens can be suppressed. In addition, since the insert member is fitted to both the lens and the lens barrel, a gap that allows the lens to move freely is not formed between the lens barrel and the lens, and therefore the lens can be prevented from rattling, causing deterioration in resolution performance and misalignment of the optical axis, which leads to deterioration in optical performance.

In the above configuration, it is preferable that the interposing member has a linear expansion coefficient (thermal expansion coefficient) equal to that of the lens it supports. This can prevent the lens from receiving compressive stress from the interposing member when it expands as it is fitted into the interposing member. It is also preferable that the interposing member is made of a material that can absorb the expansion of the lens, for example a material that has a lower flexural modulus at room temperature than the lens material. Furthermore, the interposing member may be incorporated into the lens barrel, for example, in a state where it is fitted onto the outer periphery of the lens. This allows for smooth incorporation of the lens into the lens barrel via the interposing member, particularly in an incorporation form in which an aperture is inserted between the lenses.

In addition, in the above configuration of the present invention, in a cross section perpendicular to the optical axis, the lens fitting portion of the insert member may be in point contact with the lens, and the lens barrel fitting portion of the insert member may be in line contact with the lens barrel. This allows the lens to be reliably and stably supported by the lens barrel via the insert member while minimizing the stress that the lens receives from the insert member. However, both the lens fitting portion and the lens barrel fitting portion may be in line contact or point contact.

In addition, in the above-described configuration of the present invention, the insert member may have lens fitting portions and lens barrel fitting portions arranged alternately along its circumferential direction. This allows the lens support force (lens support stability) by the insert member, as well as the fitting force (stress) that the lens barrel and lens receive from the insert member, to be evenly distributed in the circumferential direction, achieving a mechanically favorable structural form of the lens unit. Of course, it is not necessarily required that the lens fitting portions and lens barrel fitting portions be arranged alternately.

In addition, in the above-described configuration of the present invention, the circumferential positions of the lens fitting portion and the lens barrel fitting portion of the insert member of the lenses adjacent to each other in the optical axis direction may be the same or different. If the circumferential positions of the lens fitting portion and the lens barrel fitting portion of the insert member of the lenses adjacent to each other in the optical axis direction are different from each other, it is possible to disperse stress along the optical axis direction and realize a mechanically favorable structural form of the lens unit.

In the above configuration, the materials of the lens barrel and the lens, the mounting form of the lens, the shape of the inner surface of the lens barrel, etc. can be set arbitrarily. For example, the inner surface of the lens barrel that mounts and supports the lens may have a circular cross section, or a polygonal cross section. Regardless of the cross-sectional shape, the insertion member of the above configuration can be effectively inserted between the lens and the lens barrel.

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

The present invention provides a lens unit and camera module that can accurately center and position the lens within the lens barrel while suppressing the compressive stress that the lens receives from the lens barrel due to its thermal expansion, and can regulate the decentering of the lens relative to the optical axis.

3 is a schematic cross-sectional view of the lens unit according to the first embodiment of the present invention, and is a longitudinal cross-sectional view (cross-sectional view parallel to the optical axis) taken along line BB in FIG. 2. FIG. 2 is a cross-sectional view of the lens unit taken along line AA in FIG. 1 (a cross section perpendicular to the optical axis). FIG. 3 is an enlarged view of a portion X enclosed in a circular frame in FIG. 2 . 2 is a schematic cross-sectional view of a camera module having the lens unit of FIG. 1. FIG. 11 is a longitudinal sectional view (a sectional view parallel to the optical axis) of a lens unit according to a second embodiment of the present invention. FIG. 11 is a cross-sectional view (cross-section perpendicular to the optical axis) of a lens unit according to a third embodiment of the present invention. FIG. 10 is a schematic cross-sectional view of a lens unit according to a fourth embodiment of the present invention, and is a longitudinal cross-sectional view (cross-sectional view parallel to the optical axis) taken along line DD in FIG. 8. FIG. 8 is a cross-sectional view of the lens unit taken along line CC in FIG. 7 (a cross section perpendicular to the optical axis). FIG. 1 is a schematic cross-sectional view (longitudinal cross-sectional view parallel to the optical axis) of a conventional lens unit.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
The lens unit of the present embodiment described below is particularly for a camera module such as an in-vehicle camera, and is fixedly installed on the outer surface of a vehicle, with wiring drawn into the vehicle and connected to a display or other devices. Also, hatching of the lenses is omitted in Figures 1 to 9.

1 shows a lens unit 11 according to a first embodiment of the present invention. As shown in the figure, the lens unit 11 of this embodiment includes a cylindrical lens barrel 12 made of, for example, resin (or metal), a plurality of lenses arranged in a stepped inner storage space S of the lens barrel 12, for example, five lenses consisting of a first lens 13, a second lens 14, a third lens 15, a fourth lens 16, and a fifth lens 17 from the object side, and two diaphragm members 22a and 22b. In this embodiment, the diaphragm members 22a and 22b are interposed between the second lens 14 and the third lens 15, and between the third lens 15 and the fourth lens 16, and are "aperture diaphragms" that limit the amount of transmitted light and determine the F-number, which is an index of brightness, or "light-shielding diaphragms" that block light rays that cause ghosts and light rays that cause aberrations. An in-vehicle camera equipped with such a lens unit 11 includes the lens unit 11, a substrate having an image sensor (not shown), and an installation member (not shown) for installing the substrate on a vehicle such as an automobile.

The lenses 13, 14, 15, 16, and 17 are assembled and held in the inner storage space S of the lens barrel 12, and are stacked and arranged with their optical axes aligned. The lenses 13, 14, 15, 16, and 17 are arranged along a single optical axis O to form a group of lenses L used for imaging. In this case, the first lens 13, which is positioned closest to the object and is a spherical glass lens with a convex surface on the object side and a concave surface on the image side, and the other lenses 14, 15, 16, and 17 are resin lenses, but are not limited to this (for example, the first lens 13 may be a resin lens). In addition, the surfaces of these lenses 13, 14, 15, 16, and 17 are provided with anti-reflection films, hydrophilic films, water-repellent films, etc., as necessary.

In this embodiment, the two fourth and fifth lenses 16 and 17 located on the image side constitute a cemented lens (composite lens) 40. The fourth and fifth lenses 16 and 17 constituting such cemented lens 40 are assembled by fitting the annular convex portion 16a on the surface facing the image side of the fourth lens 16 located on the object side into the corresponding annular concave portion 17b on the surface facing the object side of the fifth lens 17 located on the image side, as shown in the figure, and are fixed together by adhesive or the like.

In this embodiment, an O-ring 26 is inserted between the first lens 13, which is located closest to the object, and the lens barrel 12 as a seal member to prevent water and dust from entering the lens group L inside the lens barrel 12. In this case, a stepped reduced diameter portion 13d, the diameter of which is reduced at the image side portion of the lens 13, is provided on the outer peripheral side surface 13c of the first lens 13, and an O-ring 26 is attached to this reduced diameter portion 13d, and the O-ring 26 is compressed in the radial direction between the outer peripheral side surface 13c of the first lens 13 and the inner peripheral surface of the lens barrel 12, sealing the object side end of the lens barrel 12.

Inside the lens barrel 12, a cylindrical inner wall 12b is provided on the object side, and a groove is formed between the inner wall 12b and the outer wall 12a. An annular body 27 is provided in the groove, and an O-ring 26 is in close contact with the annular body 27. The reason for forming a groove between the inner wall 12b and the outer wall 12a is to prevent a large sink mark from occurring when molding and cooling the resin lens barrel 12, which would cause a loss of dimensional accuracy, since the wall thickness would be thick if the inner wall 12b and the outer wall 12a were integrated without a groove. The annular body 27 is made of a relatively soft elastic material, such as Teflon. The annular body 27 has the function of supporting the O-ring 26 in the optical axis direction. Since the annular body 27 is a separate member from the lens barrel 12, it is possible to change the annular body 27 to a different height depending on the size of the O-ring 26, ensuring that the O-ring 26 seals with an appropriate elastic force.

In addition, when the lens group L is assembled and housed in the inner housing space S of the lens barrel 12, the crimping portion 23 at the object side end (upper end in FIG. 1) is crimped radially inward, so that the first lens 13, which is located closest to the object side of the lens group L, is fixed to the object side end of the lens barrel 12 by this crimping portion 23. Note that the fixing of the first lens 13 is not limited to the crimping portion 23, and may be performed by a fixing portion that is attached to the object side end of the lens barrel 12 after the lenses 13, 14, 15, 16, and 17 are housed in the lens barrel 12.

The end of the lens barrel 12 on the image side (the lower end in FIG. 1) is provided with an inner flange portion 24 having an opening with a smaller diameter than the fifth lens 17. The inner flange portion 24 and the crimped portion 23 hold and fix the lenses 13, 14, 15, 16, and 17 and the aperture members 22a and 22b that make up the lens group L inside the lens barrel 12 in the optical axis direction.

The lens unit 11 of this embodiment also has a lens support section 80 that supports at least one of the lenses constituting the lens group L, particularly all of the lenses 14, 15, and 17 except for the first lens 13 and one of the cemented lenses, here the fourth lens 16, in a fitted state in this embodiment. Specifically, in this embodiment, the lens support section 80 is formed by the lens barrel 12 having a circular cross section and an annular insert member 30 that is inserted between the outer peripheral side surface 14a (15a, 17a) of the lenses 14, 15, and 17 and the inner surface 12c of the lens barrel 12, as shown in Figures 1 and 2.

The lens support section 80 of this embodiment, which is formed by the lens barrel 12 and the insert member 30, has a non-contact area 70 where the lens barrel 12 and the lenses 14, 15, and 17 do not come into contact with each other, and in this embodiment in particular, where the lens barrel 12 and the insert member 30 do not come into contact with the lenses 14, 15, and 17, and a positioning support area 72 that supports the lenses 14, 15, and 17 with respect to the lens barrel 12 (by the insert member 30 in this embodiment) and positions them concentrically with the optical axis O.

2, the insert member 30 forming the lens support portion 80 together with the lens barrel 12 has a lens fitting portion 30a that fits with the lens 14 (15, 17) without contacting the lens barrel 12 to form a positioning support region 72, and a lens barrel fitting portion 30b that fits with the lens 14 (15, 17) without contacting the lens barrel 12 to form a non-contact region 70 together with the lens barrel 12, in order to position the corresponding lens 14 (15, 17) concentrically with the optical axis O without contacting the lens barrel 12. At least one of these lens fitting portion 30a and lens barrel fitting portion 30b may be provided on at least a portion of the circumferential direction of the annular insert member 30, but in this embodiment in particular, the insert member 30 has the lens fitting portion 30a and the lens barrel fitting portion 30b alternately and continuously along the circumferential direction (therefore, the non-contact region 70 and the positioning support region 72 are provided alternately and continuously along the circumferential direction). Specifically, three linear lens fitting portions 30a and three arc-shaped lens barrel fitting portions 30b are positioned adjacent to each other. In this case, as can be seen from Fig. 2, in a cross section perpendicular to the optical axis O, the lens fitting portions 30a of the insert member 30 are in point contact with the lens 14 (15, 17) (the contact points are indicated by C1 in Fig. 2), and the lens barrel fitting portions 30b are in line contact with the lens barrel 12 (the line contact portion is indicated by C2 in Fig. 2).
As shown enlarged in Figure 3, the insert member 30 is supported at its lens barrel fitting portion 30b by a step portion 12d formed on the inner surface 12c of the lens barrel 12, and further movement in the optical axis direction toward the image side is prevented.

In addition, as shown in FIG. 2, in this embodiment, the thickness T2 along the radial direction of the positioning support region 72 formed by the insert member 30 (in this embodiment, the thickness T2 of the lens fitting portion 30a) is set to be thinner than the thickness T1 along the radial direction of the non-contact region 70 formed by the lens barrel 12 and the insert member 30 (in this embodiment, the sum of the thickness of the lens barrel 12 and the thickness of the lens barrel fitting portion 30b).

As can be seen from FIG. 1, in this embodiment, the circumferential positions of the lens fitting portion 30a and the lens barrel fitting portion 30b of the insert member 30 of the lenses adjacent to each other in the direction of the optical axis O (the adjacent second lens 14 and third lens 15; the adjacent third lens 15 and cemented lens 40 (here, the fifth lens 17)) are the same. In other words, when viewed from the direction of the optical axis O, the circumferential positions of the lens fitting portion 30a and the lens barrel fitting portion 30b of the insert member 30 of each lens 14, 15, 17 are completely aligned.

It is preferable that the insert member 30 has a linear expansion coefficient (thermal expansion coefficient) equal to that of the lens 14 (15, 17) that it supports. This can prevent the lens 14 (15, 17) from receiving compressive stress from the insert member 30 when it expands as it is fitted into the insert member 30. The insert member 30 may be made of a material that can absorb the expansion of the lens 14 (15, 17). Examples of materials that form the insert member 30 include nylon-based materials such as Reny and Zylon (trademarks). In the case of a resin lens barrel, it is preferable to use the same material for the insert member 30 as the lens barrel in order to match the linear expansion coefficient of the lens barrel. Furthermore, the insert member 30 may be incorporated into the lens barrel 12 in a state where it is fitted around the outer periphery of the lens 14 (15, 17).

Figure 4 is a schematic cross-sectional view of a camera module 300 of this embodiment having a lens unit 11 configured as described above. As shown in the figure, this camera module 300 is configured to include the lens unit 11 of Figure 1 to which a filter 100 is attached.

The camera module 300 includes an upper case (camera case) 301, which is an exterior component, and a mount (base) 302 that holds the lens unit 11. The camera module 300 also includes a sealing member 303 and a package sensor (imaging element) 304.

The upper case 301 is a member that engages with the flange portion 25 that is provided in a brim-like shape on the outer circumferential surface 12a of the lens barrel 12, and exposes the object side end of the lens unit 11 and covers the other parts. The mount 302 is disposed inside the upper case 301, and has a female thread 302a that screws into the male thread 11a of the lens unit 11. The seal member 303 is a member that is interposed between the inner surface of the upper case 301 and the outer circumferential surface 12a of the lens barrel 12 of the lens unit 11, and is a member that maintains airtightness inside the upper case 301.

The package sensor 304 is disposed inside the mount 302, and is positioned to receive the image of the object formed by the lens unit 11. The package sensor 304 also has a transparent cover on the outside and is equipped with a CCD, CMOS, etc. inside, and converts the light that is collected and reaches it through the lens unit 11 into an electrical signal. The converted electrical signal is then converted into analog data or digital data, which is a component of the image data captured by the camera.

As described above, according to this embodiment, the lens support portion 80 that supports the lens 14 (15, 17) in a fitted state has a non-contact region 70 where the lens barrel 12 and the lens 14 (15, 17) do not come into contact with each other, and a positioning support region 72 that supports the lens 14 (15, 17) with respect to the lens barrel 12 and positions it concentrically with the optical axis O, and the radial thickness T2 of the positioning support region 72 is set to be thinner than the radial thickness T1 of the non-contact region 70. In other words, the lens 14 (15, 17) is supported by the lens barrel 12. While ensuring a non-contact region 70 that does not contact lens 14 (15, 17), the thickness of the lens support portion 80 is set thin in the positioning support region 72 where the lens 14 (15, 17) may indirectly receive compressive stress from the lens barrel 12 when the lens 14 (15, 17) thermally expands. This effectively allows the thermal expansion of the lens 14 (15, 17) to escape not only in the non-contact region 70 but also in the positioning support region 72, thereby alleviating the compressive stress acting on the lens 14 (15, 17) and suppressing deformation of the surface shape of the lens 14 (15, 17) due to the compressive stress. In addition, while the lens support section 80 includes a non-contact area 70 where the lens barrel 12 and the lens 14 (15, 17) do not come into contact, the positioning support area 72 reliably supports the lens 14 (15, 17) relative to the lens barrel 12 and positions it concentrically with the optical axis O, so there is no risk of the lens 14 (15, 17) rattling, causing degradation of resolution performance or misalignment of the optical axis, which could lead to degradation of optical performance.

In particular, in this embodiment, an annular interposing member 30 having a lens fitting portion 30a that fits with the lens 14 (15, 17) without contacting the lens barrel 12 to form a positioning support region 72, and a lens barrel fitting portion 30b that fits with the lens barrel 12 without contacting the lens 14 (15, 17) to form a non-contact region 70 together with the lens barrel 12 is used as a member that forms a lens support portion together with the lens barrel 12, and is connected to the outer peripheral side surface 14a (15a, 17a) of the lens 14 (15, 17) and the inner surface 12c of the lens barrel 12. Since the lens 14 (15, 17) is positioned concentrically with the optical axis O without contacting the lens barrel 12 by the insert member 30, that is, since the lens 14 (15, 17) is not directly contacted and fitted to the lens barrel 12 over the entire circumference inside the lens barrel 12, even if there is a difference in the linear expansion coefficient (thermal expansion coefficient) between the lens barrel 12 and the lens 14 (15, 17), the lens 14 (15, 17) is not affected by the lens barrel 12. In other words, even if the lens 14 (15, 17) inside the lens barrel 12 thermally expands in a high-temperature environment, for example, the lens 14 (15, 17) is not subjected to compressive stress from the lens barrel 12, and therefore, the decentering of the lens 14 (15, 17) can be regulated and deformation of the lens 14 (15, 17) can also be suppressed. In addition, because the insert 30 is fitted to both the lens 14 (15, 17) and the lens barrel 12, no gap is formed between the lens barrel 12 and the lens 14 (15, 17) that would allow the lens 14 (15, 17) to move freely. This prevents the lens 14 (15, 17) from rattling, resulting in degradation of resolution performance and misalignment of the optical axis, and thus a deterioration of optical performance.

In addition, according to this embodiment, the insert member 30 has lens fitting portions 30a and lens barrel fitting portions 30b arranged alternately along its circumferential direction, so that the support force of the insert member 30 for the lens 14 (15, 17) (support stability of the lens 14 (15, 17)) and the fitting force (stress) that the lens barrel 12 and the lens 14 (15, 17) receive from the insert member 30 can be evenly distributed in the circumferential direction, realizing a mechanically favorable structural form of the lens unit 11.

In addition, according to this embodiment, in a cross section perpendicular to the optical axis O, the lens fitting portion 30a of the insert member 30 is in point contact with the lens 14 (15, 17), and the lens barrel fitting portion 30b of the insert member 30 is in line contact with the lens barrel 12. This minimizes the stress that the lens 14 (15, 17) receives from the insert member 30, while ensuring reliable and stable support of the lens 14 (15, 17) by the lens barrel 12 via the insert member 30.

Figure 5 shows a second embodiment of the present invention. As shown in the figure, in the lens unit 11A according to this embodiment, the lenses adjacent to each other in the optical axis O direction (adjacent second lens 14 and third lens 15; adjacent third lens 15 and cemented lens 40 (here, fifth lens 17)) have different circumferential positions of the lens fitting portion 30a and the lens barrel fitting portion 30b of the interposed member 30. This is the only point that differs from the first embodiment. That is, when viewed from the direction of the optical axis O, the circumferential positions of the lens fitting portion 30a and the lens barrel fitting portion 30b of the interposed member 30 of each lens 14, 15, 17 do not match. For example, at a certain circumferential position, the lens barrel fitting portion 30b is located in the interposed member 30 of the second lens 14, while the lens fitting portion 30a is located in the interposed member 30 of the third lens 15. Furthermore, at a given circumferential position, the lens barrel fitting portion 30b is located in the insert member 30 of the third lens 15, whereas the lens fitting portion 30a is located in the insert member 30 of the fifth lens 17.

In this way, if the circumferential positions of the lens fitting portion 30a and the lens barrel fitting portion 30b of the insert member 30 are different between lenses adjacent to each other in the direction of the optical axis O, it is possible to disperse stress along the direction of the optical axis O, and a mechanically favorable structural form of the lens unit can be realized.

Figure 6 shows a third embodiment of the present invention. As shown in the figure, in the lens unit 11B according to this embodiment, the interposing member 30A has a hexagonal shape in which three linear lens fitting portions 30a that make point contact with the lens 14 (15, 17) and three linear lens fitting portions 30b that make line contact with the lens barrel 12A are adjacent to each other and alternately positioned in succession along the circumferential direction so as to be interposed between the lens barrel 12A having an inner surface 12c with a hexagonal cross section and the lens 14 (15, 17). This is the only point that makes the interposing member 30A different from the first and second embodiments. With such an interposing member 30A, the same effect as the above-mentioned embodiment can be achieved. Note that the shape of the inner surface 12c of the lens barrel 12A does not have to be hexagonal, but may be a square, pentagon, octagon, etc., and the interposing member 30A can have a polygonal shape corresponding to the shape. In this case, in order to miniaturize the lens barrel 12A and stably support the lens, it is preferable that the lens fitting portion 30a and the inner surface 12c of the lens barrel 12A facing it are parallel to each other.

7 and 8 show a fourth embodiment of the present invention. As shown in the figures, in the lens unit 11C according to this embodiment, the lens support portion 80A that supports the lenses 14, 15, and 17 in a fitted state is formed only by the lens barrel 12B having a circular cross section, without the aforementioned insert member 30 (30A). Specifically, the lens support portion 80A of the present embodiment has a non-contact region 70 where the lens barrel 12B and the lenses 14, 15, and 17 do not come into contact with each other, and a positioning support region 72 which supports the lenses 14, 15, and 17 with respect to the lens barrel 12B (in this embodiment, the lenses 14, 15, and 17 are directly supported by the lens barrel 12B (therefore, the lenses 14, 15, and 17 are in direct contact with the lens barrel 12B)) and positions them concentrically with the optical axis O, and the positioning support region 72 is formed by a thin-walled portion 12e of the lens barrel 12B which is substantially linear and makes, for example, point contact with the lenses 14, 15, and 17 in a cross section perpendicular to the optical axis O. In this case, the thin-walled portion 12e is formed by providing a recessed groove 90 facing radially inward in the outer peripheral surface portion of the lens barrel 12B which forms the positioning support region 72 of the lens support portion 80A. That is, in this embodiment, the thickness T2 along the radial direction of the portion of the barrel 12B that forms the positioning support region 72 (i.e., the thin-walled portion 12e) is thinner than the thickness T1 along the radial direction of the portion of the barrel 12B that forms the non-contact region 70. Also, if the circumferential positions of the thin-walled portions 12e of the lenses 14, 15, and 17 are aligned (the thin-walled portions 12e are biased in only one direction), deformation of the barrel 12B may occur. Therefore, in this embodiment, the positions of the thin-walled portions 12e are staggered for each of the lenses 14, 15, and 17. That is, the circumferential positions of the thin-walled portions 12e (positioning support region 72) (and therefore the circumferential positions of the non-contact region 70) of the lenses adjacent to each other in the optical axis O direction (the adjacent second lens 14 and third lens 15; the adjacent third lens 15 and cemented lens 40 (here, the fifth lens 17)) are different from each other. For example, at a given circumferential position, the thin portion 12e (positioning support region 72) is located in the second lens 14, whereas the non-contact region 70 is located in the third lens 15. Also, at a given circumferential position, the thin portion 12e (positioning support region 72) is located in the third lens 15, whereas the non-contact region 70 is located in the fifth lens 17.

In addition, in this embodiment, the lens support portion 80A is formed by alternately and continuously providing non-contact areas 70 and positioning support areas 72 along the circumferential direction, and the inner surface 12c of the lens barrel 12B forming the non-contact areas 70 and the positioning support areas 72 is linear in a cross section perpendicular to the optical axis O. Therefore, the lens barrel 12B has an inner surface 12c with a polygonal cross section (hexagonal in FIG. 8). However, the inner surface 12c of the lens barrel 12B forming the non-contact areas 70 and/or the positioning support areas 72 may be arc-shaped. In this embodiment, the lens support portions 80A of the lenses adjacent to each other in the optical axis direction have the same circumferential positions of the non-contact areas 70 and the positioning support areas 72, but they may be different from each other.

As described above, in this embodiment, as in the above-described embodiment, the lens support portion 80A that supports the lens 14 (15, 17) in a fitted state has a non-contact region 70 where the lens barrel 12B and the lens 14 (15, 17) do not come into contact with each other, and a positioning support region 72 that supports the lens 14 (15, 17) relative to the lens barrel 12B and positions it concentrically with the optical axis O. In addition, the thickness T2 along the radial direction of the positioning support region 72 is set to be thinner than the thickness T1 along the radial direction of the non-contact region 70. In other words, the lens 14 (1 While ensuring a non-contact region 70 that does not allow lens 14 (15, 17) to come into contact with lens barrel 12B, the thickness of lens support portion 80A is set thin in positioning support region 72 where lens 14 (15, 17) may directly receive compressive stress from lens barrel 12B when lens 14 (15, 17) thermally expands. As a result, thermal expansion of lens 14 (15, 17) can be effectively released not only in non-contact region 70 but also in positioning support region 72, thereby alleviating the compressive stress acting on lens 14 (15, 17) and suppressing deformation of the surface shape of lens 14 (15, 17) due to the compressive stress. In addition, while the lens support section 80A includes a non-contact area 70 where the lens barrel 12B and the lens 14 (15, 17) do not come into contact, the positioning support area 72 reliably supports the lens 14 (15, 17) relative to the lens barrel 12B and positions it concentrically with the optical axis O, so there is no risk of the lens 14 (15, 17) rattling, causing degradation of resolution performance or misalignment of the optical axis, which could lead to degradation of optical performance.

The present invention is not limited to the above-described embodiment, and can be modified in various ways without departing from the gist of the present invention. For example, the shapes of the lenses, lens barrel, interposing members, etc. are not limited to those of the above-described embodiment. In addition, in the above-described embodiment, the second, third, and fifth lenses are provided with lens support portions (interposing members), but in cases where the fourth lens and the fifth lens are not cemented lenses 40, for example, lens support portions may be provided on all lenses, including the first lens and the fourth lens (interposing members may be interposed between all lenses and the lens barrel).

11, 11A, 11B, 11C Lens unit 12, 12A Lens barrel 12c Inner surface 13, 14, 15, 16, 17 Lens 14a, 15a, 17a Outer circumferential side surface 30 Insertion member 30a Lens fitting portion 30b Lens barrel fitting portion 70 Non-contact area 72 Positioning support area 80, 80A Lens support portion 300 Camera module O Optical axis S Inner storage space

Claims (8)

A lens unit comprising: a cylindrical lens barrel forming an inner storage space for storing and holding a lens; and a lens group assembled in the inner storage space of the lens barrel and including a plurality of lenses arranged along an optical axis,
an annular insertion member that is inserted between an outer peripheral side surface of the lens and an inner surface of the lens barrel to position the lens concentrically with the optical axis without contacting the lens barrel;
the insertion member has a lens fitting portion that fits with the lens without contacting the lens barrel, and a lens barrel fitting portion that fits with the lens barrel without contacting the lens,
a thickness along a radial direction of the lens fitting portion is smaller than a sum of a thickness along a radial direction of the lens barrel fitting portion and a thickness along a radial direction of the lens barrel that fits into the lens barrel fitting portion,
a lens unit characterized in that, in a cross section perpendicular to the optical axis, the lens barrel fitting portion is in line contact with the inner surface of the lens barrel over its entirety, and the lens fitting portion extends in a straight line between the lens barrel fitting portions while making point contact with the lens so as to connect the lens barrel fitting portions to each other. The lens unit according to claim 1, characterized in that the interposing member has the lens fitting portions and the lens barrel fitting portions arranged alternately along its circumferential direction. The lens unit according to claim 2, characterized in that the circumferential positions of the lens fitting portion and the lens barrel fitting portion of the insert member are the same for lenses adjacent to each other in the optical axis direction. The lens unit according to claim 2, characterized in that the circumferential positions of the lens fitting portion and the lens barrel fitting portion of the insert member are different between lenses adjacent to each other in the optical axis direction. A lens unit comprising: a cylindrical lens barrel forming an inner storage space for storing and holding a lens; and a lens group assembled in the inner storage space of the lens barrel and including a plurality of lenses arranged along an optical axis,
the lens barrel has a non-contact area that does not come into contact with the lens, and a positioning support area that directly supports the lens and positions it concentrically with the optical axis,
The positioning support region is set to have a smaller thickness along a radial direction than the non-contact region,
a lens unit characterized in that all of the positioning support areas extend linearly between the non-contact areas while making point contact with the lens so as to connect the non-contact areas in a cross section perpendicular to the optical axis, and have a linear outer peripheral surface connecting the arc-shaped outer peripheral surfaces of the non-contact areas, and a linear inner peripheral surface connecting the linear inner peripheral surfaces of the non-contact areas. The lens unit according to any one of claims 1 to 4, characterized in that the lens barrel has an inner surface with a circular cross section. The lens unit according to any one of claims 1 to 5, characterized in that the lens barrel has an inner surface with a polygonal cross section. A camera module comprising a lens unit according to any one of claims 1 to 7.