JP2016018182A - Lens unit, and method of manufacturing holder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lens unit that employs a holder allowing a lens to be appropriately centered without spending a lot of cots, and a method of manufacturing the holder.SOLUTION: Upon manufacturing a holder 30 of a lens unit by means of resin molding, a plurality of salients for centering 345 that protrudes inwardly in a radial direction and abuts on an outer peripheral side surface of a lens is formed in the holder 30, and the lens is centered using the salients for centering 345. Upon manufacturing the holder 30 by means of the resin molding, a recesses 115 for forming the salients 345 for centering are formed at a plurality of portions in a peripheral direction in an outer circumferential surface 110 of a first metal mold 100, and after manufacturing the holder 30 using the first metal mold 100, a virtual circle C0 is obtained that is inscribed on the plurality of salients for centering 345. Of the recesses 115 at the plurality of portions, for the recess 115 forming the salient 345 for centering whose inner end 346 is not located on the virtual circle C0, a metal mold correction process is performed that adjusts a depth.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a lens unit in which a plurality of lenses are aligned in a holder, and a method for manufacturing the holder.

  In a lens unit used in an imaging device or the like, cylindrical holders are formed at a plurality of locations in the optical axis direction of the holder, and the inner peripheral surface of the lens holder and the outer peripheral end surface of the lens are in contact with each other. Alignment is performed (see Patent Document 1). In addition, a structure has been proposed in which convex portions projecting with the same dimension are provided radially inward at a plurality of locations in the circumferential direction of the lens holding portion, and the convex portions are brought into contact with the outer peripheral end surface of the lens (see Patent Document 2).

JP 2011-215183 A JP 2005-266227 A

  When manufacturing the holder shown by patent document 1 by injection molding, the 1st metal mold | die 100x and the 2nd metal mold | die 200x shown to Fig.7 (a) are used. Specifically, the first mold 100x is disposed in the hollow part 210x of the second mold 200x, and the inner peripheral surface 220x of the hollow part 210x of the second mold 200x and the outer peripheral surface 110x of the first mold 100 are The holder 30x is manufactured by introducing resin between the two. Here, if the inner peripheral surface 300x of the holder 30x is a perfect circle as shown by a one-dot chain line C1 in FIG. 7B, the lens can be properly aligned.

  However, depending on the influence of the shape of the holder 30x and the position of the gate during resin molding, the inner peripheral surface 300x of the holder 30x becomes a shape distorted from a perfect circle as shown by the solid line C2 in FIG. There is. When such a situation occurs, when the lens is inserted, the lens may be decentered, and the holder 30x may be deformed, resulting in decentering of the other lenses.

  Accordingly, as shown in FIG. 7C, the shape of the outer peripheral surface 110x of the first mold 100x is corrected so as to correct the distortion indicated by the solid line C2 in FIG. 7B. The work takes a lot of labor, and the shape of the inner peripheral surface 300x of the holder 30x cannot often be corrected by one correction. In addition, the distortion of the inner peripheral surface 300x of the holder 30x may be such that the inner peripheral surface 300x of the holder 30 has a quadrilateral shape in addition to the shape shown in FIG. 7B. The modification of the mold 100x takes a lot of time and in many cases, the shape of the inner peripheral surface 300x of the holder 30x cannot be corrected by one modification. Such a problem is difficult to solve even if the configuration described in Patent Document 2 is adopted.

  In view of the above problems, an object of the present invention is to provide a lens unit using a holder that can properly align a lens without much cost, and a method for manufacturing the holder. .

In order to solve the above problems, the present invention includes a plurality of lenses arranged along an optical axis, and a resin holder including a plurality of cylindrical lens holding portions that hold the plurality of lenses. In the lens unit, at least one of the plurality of lens holding portions includes a plurality of alignment convex portions protruding inward in the radial direction from the inner peripheral surface and contacting the outer peripheral side surface of the lens in the circumferential direction. The plurality of alignment convex portions include a first alignment convex portion, and a protrusion dimension from the inner peripheral surface is the first alignment convex portion. Different second alignment convex portions are included.

  “Alignment” in the present invention means that the center of the lens is aligned in a direction perpendicular to the optical axis.

  The present invention forms an inner peripheral surface of at least one lens holding portion of the plurality of lens holding portions when manufacturing a holder having a plurality of cylindrical lens holding portions in the optical axis direction by resin molding. On the outer peripheral surface of the mold, concave portions for forming alignment convex portions on the inner peripheral surface are formed in a plurality of locations in the circumferential direction, and after manufacturing the holder using the mold, A virtual circle inscribed in a plurality of alignment convex portions is obtained, and the depth of the concave portions forming the alignment convex portions whose inner ends are not located on the virtual circle among the plurality of concave portions is adjusted. A mold correction step is performed, and then the holder is manufactured by resin molding.

  In the present invention, a plurality of alignment convex portions that protrude inward in the radial direction and come into contact with the outer peripheral side surface of the lens are formed on the lens holding portion of the holder, and the alignment of the lens is adjusted by these alignment convex portions. Do. Here, when manufacturing the holder by resin molding, concave portions for forming alignment convex portions on the outer peripheral surface of the mold are formed at a plurality of locations in the circumferential direction, and the holder is manufactured using the mold. Thereafter, a virtual circle inscribed in the plurality of alignment convex portions is obtained, and the depth of the concave portions forming the alignment convex portions whose inner ends are not located on the virtual circle among the plurality of concave portions is adjusted. Perform mold correction process. For this reason, the lens is properly aligned by the first alignment convex portion and the second alignment convex portion whose protrusion dimensions are different due to the correction to the mold. In addition, since the mold may be corrected with respect to the recess, the mold correcting process does not require much labor. Therefore, according to the present invention, it is possible to properly align the lens without enormous costs.

  In the present invention, the lens holding portions with convex portions are provided at a plurality of positions adjacent in the optical axis direction, and the alignment convex portions at the lens holding portions with the convex portions provided at the plurality of locations are in the optical axis direction. It is preferable that it is formed continuously. According to such a configuration, when the holder and the mold are separated from each other in the optical axis direction after the holder is molded, it is difficult for the hook due to the alignment convex portion to occur.

  In the present invention, an arc surface and a flat surface adjacent to the arc surface in the circumferential direction are formed on the outer peripheral surface of the holder, and the alignment convex portion is the lens with the convex portion. It is preferable that the inner circumferential surface of the holding portion is provided in an angle range where the arc surface is formed. In the angle range in which the outer peripheral surface is an arc surface, since the distortion of the shape of the inner peripheral surface of the lens holding portion is less likely to occur than in the angle range in which a flat surface is formed, an arc portion is formed. If the alignment convex portion is provided in the angle range, the mold can be corrected efficiently.

  In the present invention, it is preferable that among the plurality of lens holding portions, at least a lens holding portion having a shortest distance in the optical axis direction from the flat surface is the lens holding portion with a convex portion. In the lens holding part close to the flat surface in the optical axis direction, the shape of the inner peripheral surface tends to be distorted, so if such a lens holding part is a lens holding part with a convex part, Thus, it is possible to properly align the lens at a position close in the optical axis direction.

In the present invention, the holder includes a circular first outer peripheral surface, and a second outer peripheral surface provided at a position adjacent to the first outer peripheral surface in the optical axis direction and having a shape other than a circular shape, Of the plurality of lens holding portions, it is preferable that at least the lens holding portion with the shortest distance in the optical axis direction from the second outer peripheral surface is the lens holding portion with the convex portion. When the second outer peripheral surface having a shape other than a circle is formed, the lens holding portion at a position close to the second outer peripheral surface in the optical axis direction is likely to be distorted in the shape of the inner peripheral surface. If such a lens holding part is a lens holding part with a convex part, it is possible to properly align the lens at a position close to the second outer peripheral surface in the optical axis direction.

  In the present invention, a diaphragm is disposed between any two of the plurality of lenses, and a lens adjacent to the diaphragm on one side in the optical axis direction among the plurality of lens holding portions. It is preferable that at least one of the holding lens holding portion and the holding lens holding portion adjacent to the diaphragm on the other side in the optical axis direction is the convex lens holding portion. Since a lens that is close to the stop in the optical axis direction requires high alignment accuracy, if the lens holding part that holds such a lens is a lens holding part with a convex part, the lens close to the stop is properly Can be aligned.

  In the present invention, a plurality of alignment convex portions that protrude inward in the radial direction and come into contact with the outer peripheral side surface of the lens are formed on the lens holding portion of the holder, and the alignment of the lens is adjusted by these alignment convex portions. Do. Here, when manufacturing the holder by resin molding, concave portions for forming alignment convex portions on the outer peripheral surface of the mold are formed at a plurality of locations in the circumferential direction, and the holder is manufactured using the mold. Thereafter, a virtual circle inscribed in the plurality of alignment convex portions is obtained, and the depth of the concave portions forming the alignment convex portions whose inner ends are not located on the virtual circle among the plurality of concave portions is adjusted. Perform mold correction process. For this reason, the lens is properly aligned by the first alignment convex portion and the second alignment convex portion whose protrusion dimensions are different due to the correction to the mold. In addition, since the metal mold may be corrected with respect to the alignment convex portion, the metal mold correction process does not require much labor. Therefore, according to the present invention, the lens can be efficiently aligned in the holder.

It is explanatory drawing of the lens unit which concerns on Embodiment 1 of this invention. It is explanatory drawing at the time of forming the lens holding part with a convex part (4th lens holding part) with the metal mold | die before correction in the lens unit which concerns on Embodiment 1 of this invention. It is explanatory drawing of the lens holding part with convex part (4th lens holding part) formed with the metal mold | die before correction shown in FIG. It is explanatory drawing at the time of forming the lens holding part with a convex part (4th lens holding part) with the metal mold | die after correction in the lens unit which concerns on Embodiment 1 of this invention. It is explanatory drawing of the lens unit which concerns on the modification of Embodiment 1 of this invention. It is explanatory drawing of the lens unit which concerns on Embodiment 2 of this invention. It is explanatory drawing of the conventional lens unit.

  Embodiments of the present invention will be described with reference to the drawings.

[Embodiment 1]
(overall structure)
FIG. 1 is an explanatory diagram of a lens unit according to Embodiment 1 of the present invention. FIGS. 1A and 1B are a perspective view of a holder used in the lens unit and a cross-sectional view of the lens unit. .

As shown in FIG. 1, the lens unit 1 of the present embodiment includes a wide-angle lens 10 having a wide-angle lens 10 in which a plurality of lenses are arranged in the optical axis L direction, and a cylindrical holder 30 that holds the wide-angle lens 10 inside. It is a unit and is used for various imaging devices. The angle of view of the wide-angle lens 10 is, for example, 190 °. The wide-angle lens 10 has, for example, a four-group five-lens configuration. More specifically, the wide-angle lens 10 includes, in order from the object side L1 (front side), a first lens 11 (first group) having negative power, a second lens 12 (second group) having negative power, It has the 3rd lens 13 (3rd group) which has positive power, and the cemented lens 16 (4th group) which has positive power. In the cemented lens 16, the fourth lens 14 having negative power and the fifth lens 15 having positive power are cemented. In this embodiment, the first lens 11 is made of a glass lens or a plastic lens, and the second lens 12, the third lens 13, the fourth lens 14 and the fifth lens 15 are made of a plastic lens. The lens unit 1 has a diaphragm 18 between the third lens 13 and the fourth lens 14, and has an infrared cut filter 17 on the image side L <b> 2 from the fifth lens 15.

In this embodiment, the outer diameter dimensions of the second lens 12, the third lens 13, and the fourth lens 14 have the following relationship, and the second lens 12, the third lens 13, and the fourth lens 14 have the following relationship. Slightly larger in order.
2nd lens 12> 3rd lens 13> 4th lens 14

  The first lens 11 has a larger outer diameter than the second lens 12, the third lens 13, the fourth lens 14, and the fifth lens 15. Further, in the cemented lens 16, the fourth lens 14 has a larger outer diameter than the fifth lens 15.

  Corresponding to this configuration, the holder 30 includes, in order from the object side L1 (front side), a cylindrical first lens holding portion 31, a cylindrical second lens holding portion 32, a cylindrical third lens holding portion 33, And a cylindrical fourth lens holding portion 34. An annular receiving portion 36 that receives the first lens 11 is formed on the object side L1 surface of the cylindrical second lens holding portion 32 on the inner peripheral side of the holder 30. An annular step 35 for receiving the fourth lens 14 is formed on the image side of the cylindrical fourth lens holding portion 34 on the inner peripheral side of the holder 30.

  Here, the entire outer peripheral surface of the first lens holding portion 31 is an arc surface, but the outer peripheral surfaces of a part of the second lens holding portion 32, the third lens holding portion 33, and the fourth lens holding portion 34. 38, two portions in the circumferential direction are flat surfaces 381, and portions adjacent to the flat surface 381 in the circumferential direction are circular arc surfaces 382. Accordingly, when the holder 30 is resin-molded, if the gate is disposed at a position corresponding to the flat surface 381, even if a burr caused by the gate is generated, the burr hardly protrudes radially outward from the arc surface 382. Further, in the holder 30, an annular recess 39 is formed on the end surface on the image side L <b> 2 to prevent resin sink when the holder 30 is resin-molded.

  In the holder 30 configured as described above, the inner edge of the second lens holding portion 32 is crimped to press and fix the second lens 12 toward the image side L2, and the inner edge of the first lens holding portion 31 is crimped to fix the second lens 12. One lens 11 is pressed and fixed toward the image side L2.

(Alignment structure)
In the lens unit 1, the holder 30 is made of resin. The first lens 11 is press-fitted inside the first lens holding portion 31, and the inner peripheral surface of the first lens holding portion 31 is in direct contact with the outer peripheral side surface of the first lens 11, and Is aligned. On the other hand, the second lens holding portion 32, the third lens holding portion 33, and the fourth lens holding portion 34 are configured as a lens holding portion with a convex portion in which an alignment convex portion described below is formed. The second lens 12, the third lens 13, and the fourth lens 14 are press-fitted inside the alignment convex portion. For this reason, the 2nd lens 12, the 3rd lens 13, and the 4th lens 14 are aligned by the convex part for alignment. That is, the inner diameter of the inner peripheral surface of the second lens holding portion 32 is slightly larger than the outer diameter of the second lens 12, and the inner diameter of the inner peripheral surface of the third lens holding portion 33 is slightly larger than the outer diameter of the third lens 13. The inner diameter of the fourth lens holder 34 is slightly larger than the outer diameter of the fourth lens 14.

(Configuration of convex part for alignment and lens holding part with convex part)
In this embodiment, the second lens holding portion 32, the third lens holding portion 33, and the fourth lens holding portion 34 are configured as lens holding portions with convex portions having the same configuration. The configuration of the lens holding unit 34 will be mainly described. In the following description, the configuration of the fourth lens holding portion 34 will be described while explaining the method for manufacturing the holder 30.

  FIG. 2 is an explanatory diagram of the lens unit 1 according to Embodiment 1 of the present invention in the case where a lens holding part with a convex portion (fourth lens holding part 34) is formed with a mold before correction. (a), (b) is explanatory drawing of the part which forms the 4th lens holding part 34 in the metal mold | die (before correction) for resin-molding the holder 30, and explanatory drawing of the 4th lens holding part 34. FIG. FIG. 3 is an explanatory diagram of a lens holding part with a convex part (fourth lens holding part 34) formed by the mold before correction shown in FIG. FIG. 4 is an explanatory diagram of the lens unit 1 according to Embodiment 1 of the present invention in the case where a lens holding part with a convex portion (fourth lens holding part 34) is formed with a corrected mold. (a), (b) is explanatory drawing of the part which forms the 4th lens holding part 34 in the metal mold | die (after correction) for resin-molding the holder 30, and explanatory drawing of the 4th lens holding part 34. FIG.

  When the holder 30 described with reference to FIG. 1 is manufactured by injection molding, the first mold 100 and the second mold 200 shown in FIG. 2A are used. Specifically, the first mold 100 is disposed in the hollow part 210 of the second mold 200, and the inner peripheral surface 220 of the hollow part 210 of the second mold 200 and the outer peripheral surface 110 of the first mold 100 are The holder 30 is manufactured by introducing resin between the two. Here, in the second mold 200, the gates 230 are arranged at two locations corresponding to the molding surface 281 for forming the flat surface 381 of the holder 30.

  Further, in this embodiment, in the outer peripheral surface 110 of the first mold 100, concave portions 115 are formed at a plurality of locations in the circumferential direction on the portion where the fourth lens holding portion 34 is formed. In this embodiment, concave portions 115 are formed at six locations in the circumferential direction. As a result, as shown in FIG. 2B, among the inner peripheral surface 300 of the holder 30, the inner peripheral surface 340 of the fourth lens holding portion 34 has a plurality of protrusions protruding radially inward from the inner peripheral surface 340. Alignment convex portions 345 are formed at six locations. At that time, in the plurality of alignment convex portions 345, the protruding dimensions from the inner peripheral surface 340 are the same. Here, the alignment convex portion 345 is provided in an angle range in which the arc surface 382 is formed, and is not provided in an angle range in which the flat surface 381 is formed.

  In the holder 30 manufactured in this way, as shown in FIG. 2B, when a virtual circle C0 inscribed in the plurality of alignment convex portions 345 is drawn, the inner ends 346 of the plurality of alignment convex portions 345 are drawn. If the fourth lens 14 reaches the virtual circle C0, when the fourth lens 14 is press-fitted inside the alignment convex portion 345 and provided in the fourth lens holding portion 34, the fourth lens 14 is properly aligned. Is done.

  However, depending on the influence of the shape of the holder 30 (formation of the flat surface 381), the position of the gate 230 at the time of resin molding, etc., the flat surface of the inner peripheral surface 340 of the fourth lens holding portion 34 is shown in FIG. A portion where the surface 381 is formed or a portion where the gate 230 is located may have a shape projecting inward. When such a situation occurs, the inner peripheral surface 340 is retracted at a position away from the flat surface 381 or the gate 230, so that the portion where the flat surface 381 or the gate 230 is located among the plurality of alignment convex portions 345. The inner end 346 of the alignment convex portion 345 does not reach the virtual circle C0 and is not positioned on the virtual circle C0.

In such a case, as shown in FIG. 4A, in the first mold 100, of the recesses 115, the recesses 115b (forming the centering protrusions 345 in which the inner end 346 is not located on the virtual circle C0). A mold correction step is performed to adjust the depth of the concave portion 115) at a position separated from the molding surface 281 and the gate 230. In the present embodiment, the inner end 3 of the first mold 100 in the mold correction process.
Adjustment is made to increase the depth of the concave portion 115 (the concave portion 115 at a position spaced from the molding surface 281 and the gate 230) forming the alignment convex portion 345 where 46 does not reach the virtual circle C0.

  Accordingly, when the holder 30 is resin-molded using the first mold 100 and the second mold 200 after performing the mold correcting step, as shown in FIG. 4B, a plurality of alignment convex portions 345 are formed. In either case, the inner end 346 is positioned on the virtual circle C0. Therefore, when the fourth lens 14 is disposed on the fourth lens holding portion 34, the plurality of alignment convex portions 345 are all in contact with the outer peripheral side surface of the fourth lens 14, and the fourth lens 14 is adjusted properly. Cored.

  Here, the plurality of alignment convex portions 345 include a first alignment convex portion 345a formed by the concave portion 115 that has not been corrected and a second adjustment formed by the concave portion 115 that has been corrected. The protrusions 345b for cores are included, and the protrusions from the inner peripheral surface 340 of the holder 30 are different between the first alignment protrusions 345a and the second alignment protrusions 345b. That is, the second centering convex portion 345b formed by the modified concave portion 115 has a larger projecting dimension than the first centering convex portion 345a formed by the non-corrected concave portion 115. .

  Such a configuration is the same for the second lens holding unit 32 and the third lens holding unit 33. Here, the second lens holding part 32, the third lens holding part 33, and the fourth lens holding part 34 are adjacent to each other in the optical axis L direction, and the alignment convex part formed on the second lens holding part 32. 325, the alignment convex portion 335 formed on the third lens holding portion 33, and the alignment convex portion 345 formed on the fourth lens holding portion 34 are formed in a continuous rib shape in the optical axis L direction. ing. For this reason, when the holder 30 is formed and the holder 30 and the first mold 100 are separated in the direction of the optical axis L, catching due to the alignment convex portions 325, 335, and 345 hardly occurs. Therefore, the holder 30 can be manufactured without using an expensive slide mold or the like.

(Main effects of this form)
As described above, in the present embodiment, when the holder 30 is manufactured by resin molding, the fourth lens holding portion 34 of the holder 30 protrudes inward in the radial direction and comes into contact with the outer peripheral side surface of the fourth lens 14. The center convex part 345 is formed, and the centering of the fourth lens 14 is performed by the centering convex part 345. Here, when the holder 30 is manufactured by resin molding, the concave portions 115 for forming the alignment convex portions 345 on the outer peripheral surface 110 of the first mold 100 are formed at a plurality of locations in the circumferential direction. After the holder 30 is manufactured using the mold 100, a virtual circle C0 inscribed in the plurality of alignment convex portions 345 is obtained. And among the concave portions 115 at a plurality of locations, the concave portion 115 forming the alignment convex portion 345 in which the inner end 346 is not positioned on the virtual circle C0 is subjected to a die correcting step for adjusting the depth. For this reason, the fourth lens 14 is properly aligned by the first alignment convex portion 345a and the second alignment convex portion 345b whose projecting dimensions are different due to the correction to the first mold 100. In addition, since the first mold 100 may be corrected with respect to the recess 115, the correction process of the first mold 100 does not require much labor. Therefore, according to this embodiment, it is possible to properly align the fourth lens 14 in the holder 30 without incurring great costs.

  In the present embodiment, all of the six alignment convex portions 345 are in contact with the outer peripheral side surface of the fourth lens 14. That is, in this embodiment, at least three alignment convex portions 345 are in contact with the outer peripheral side surface of the fourth lens 14. For this reason, the fourth lens 14 can be properly aligned.

Further, the alignment convex portion 345 is provided in an angle range where the arc surface 382 is formed, and is not provided in an angle range where the flat surface 381 is formed. According to such a configuration, since the alignment convex portion is provided on the circular arc surface 382 in which the shape of the inner peripheral surface is less likely to be distorted, correction to the first mold 100 is minimized. Therefore, the mold correction process can be performed efficiently.

  Further, in this embodiment, in the second lens holding portion 32 and the third lens holding portion 33, the alignment convex portions 325 and 335 similar to the alignment convex portion 345 of the fourth lens holding portion 34 (FIG. 1 ( b)), the second lens 12 and the third lens 13 are aligned. For this reason, the lens holding part (the second lens holding part 32, the third lens holding part 33, and the fourth lens holding part 34) having the shortest distance in the optical axis L direction from the flat surface 381 is the alignment convex part 325. It is a lens holding part with convex parts provided with 335,345. Therefore, even when there is a tendency that shape distortion tends to occur at a position close to the flat surface 381 in the optical axis L direction, the second lens 12, the third lens 13, and the fourth lens 14 are properly aligned. be able to.

  In this embodiment, the third lens holding portion 33 that holds the third lens 13 that is adjacent to the diaphragm 18 on one side (object side L1) in the optical axis L direction, and the diaphragm 18 in the optical axis L direction. Both of the fourth lens holding portions 34 that hold the adjacent fourth lenses 14 on the other side (image side L2) of the lens are convex lens holding portions including the alignment convex portions 335 and 345. For this reason, even when high alignment accuracy is required for the third lens 13 and the fourth lens 14 located close to the stop 18 in the optical axis L direction from the viewpoint of resolution or the like, the third lens 13 and the fourth lens 14 are provided. It can be properly aligned.

[Modification of Embodiment 1]
FIG. 5 is an explanatory diagram of a lens unit 1 according to a modification of the first embodiment. In the first embodiment, all the six alignment convex portions 345 are in contact with the outer peripheral side surface of the fourth lens 14, but as shown in FIG. A configuration in which the fourth lens 14 does not come into contact with the outer peripheral side surface may be employed. For example, when the fourth lens 14 is a plastic lens, the portion 348 where the gate was located when the fourth lens 14 was molded may be flat. In such a case, there are six alignment convexities. One of the parts 345 does not contact the outer peripheral side surface of the fourth lens 14. Even in such a case, since the at least three alignment convex portions 345 are in contact with the outer peripheral side surface of the fourth lens 14, the fourth lens 14 can be properly aligned.

[Embodiment 2]
FIG. 6 is an explanatory diagram of a lens unit according to Embodiment 2 of the present invention, and FIGS. 6A and 6B are a perspective view of a holder used in the lens unit and a cross-sectional view of the lens unit. . Since the basic configuration of this embodiment is the same as that of Embodiment 1, common portions are denoted by the same reference numerals and description thereof is omitted. As shown in FIG. 6, the lens unit 1 of the present embodiment also includes a wide-angle lens 10 in which a plurality of lenses are arranged in the direction of the optical axis L, and a cylindrical shape that holds the wide-angle lens 10 on the inside, as in the first embodiment. Holder 30.

  Here, in the holder 30, a portion where the second lens holding portion 32, the third lens holding portion 33 and the fourth lens holding portion 34 are formed is a first outer peripheral surface 386 whose outer peripheral surface is circular. On the other hand, a portion adjacent to the first outer peripheral surface 386 on the image side L2 in the optical axis L direction is a flange portion 388 spreading outward in the radial direction from the first outer peripheral surface 386. For this reason, in the holder 30, a portion adjacent to the first outer peripheral surface 386 on the image side L2 in the optical axis L direction is a second outer peripheral surface 387 having a shape other than a circle. In the case of such a configuration, when the holder 30 is resin-molded, the gate is disposed on the image side L2 surface of the flange portion 388. In this embodiment, the flange portion 388 is used as a fixing portion, an alignment portion, or the like when the lens unit 1 is mounted on the imaging device.

In the lens unit 1 configured as described above, as in the first embodiment, the second lens holding portion 32, the third lens holding portion 33, and the fourth lens holding portion 34 include the alignment convex portions 325, 3 and 3, respectively.
A lens holding portion with convex portions 35 and 345 is formed. Therefore, the second lens holding portion 32, the third lens holding portion 33, and the fourth lens holding portion are affected by the shape of the flange portion 388 (second outer peripheral surface 387) of the holder 30 and the position of the gate during resin molding. Even when distortion occurs in the shape of the inner peripheral surface of 34, the second lens 12, the third lens 13, and the fourth lens 14 are properly aligned by the alignment convex portions 325, 335, and 345.

  Further, in this embodiment, the fourth lens holding portion 34 having the shortest distance in the optical axis L direction from the flange portion 388 (second outer peripheral surface 387) is a lens holding portion with a convex portion provided with a centering convex portion 345. It has become. For this reason, even when there is a tendency that distortion of the shape tends to occur near the flange portion 388 (second outer peripheral surface 387) in the optical axis L direction, the fourth lens 14 can be properly aligned. it can.

1 .. Lens unit 10.. Wide angle lens 11.. 1st lens 12.. 2nd lens 13.. 3rd lens 14.. 4th lens 15. Cemented lens, 18 .. stop, 30 .. holder, 31... First lens holding part, 32 .. second lens holding part, 33 .. third lens holding part, 34 .. fourth lens holding part, 100 ·········································· second concave portion of the die 200 ··················? 325, 335, 345 .. Alignment convex portion 345a .. First alignment convex portion 345b .. Second alignment convex portion 346 .. Inner end 381 .. Flat surface 386. First outer peripheral surface, 387 .. Second outer peripheral surface, 388 .. Flange

Claims (7)

A plurality of lenses arranged along the optical axis;
A resin holder provided with a plurality of cylindrical lens holding portions for holding the plurality of lenses;
In a lens unit having
At least one of the plurality of lens holding portions is a convex lens in which a plurality of alignment convex portions that protrude radially inward from an inner peripheral surface and abut on the outer peripheral side surface of the lens are arranged in the circumferential direction. It is a holding part,
The plurality of alignment convex portions include a first alignment convex portion and a second alignment convex portion having a projecting dimension from the inner peripheral surface different from that of the first alignment convex portion. A lens unit characterized by The convex lens holding portions are provided at a plurality of locations adjacent in the optical axis direction,
2. The lens unit according to claim 1, wherein the alignment convex portions are continuously formed in the optical axis direction in the convex lens holding portions provided at the plurality of locations. On the outer peripheral surface of the holder, an arc surface and a flat surface adjacent to the arc surface in the circumferential direction are formed,
The said centering convex part is provided in the angle range in which the said circular arc surface is formed among the internal peripheral surfaces of the said lens holding part with a convex part, The Claim 1 or 2 characterized by the above-mentioned. Lens unit.   The lens holding part with the shortest distance in the optical axis direction from the flat surface among the plurality of lens holding parts is the lens holding part with a convex part. Lens unit. The holder has a circular first outer peripheral surface, and a second outer peripheral surface provided at a position adjacent to the first outer peripheral surface in the optical axis direction and having a shape other than a circle,
2. The lens holding portion having the shortest distance in the optical axis direction from the second outer peripheral surface among the plurality of lens holding portions is the lens holding portion with a convex portion. The lens unit as described in any one of thru | or 4. A diaphragm is disposed between any two of the plurality of lenses,
Among the plurality of lens holding portions, a lens holding portion that holds a lens adjacent to the diaphragm on one side in the optical axis direction, and a lens that is adjacent to the diaphragm on the other side in the optical axis direction. The lens unit according to claim 1, wherein at least one of the lens holding portions is the lens holding portion with a convex portion. In manufacturing a holder having a plurality of cylindrical lens holding portions in the optical axis direction by resin molding,
On the outer peripheral surface of the mold forming the inner peripheral surface of at least one lens holding portion of the plurality of lens holding portions, a concave portion for forming an alignment convex portion on the inner peripheral surface is provided in the circumferential direction. Form it in several places,
After producing the holder using the mold, determine a virtual circle inscribed in the plurality of alignment convex portions,
Among the plurality of concave portions, the concave portion forming the alignment convex portion whose inner end is not located on the virtual circle, a mold correction step for adjusting the depth is performed,
Thereafter, the holder is manufactured by resin molding.

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