JP2017053932A - Lens unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lens unit improved in circularity of an inner peripheral surface of a lens barrel.SOLUTION: A lens unit 1A includes a plurality of lenses 2 and a resin-made lens barrel 3A housing the lenses 2. The lens barrel 3A has: an inside cylinder part 31; an outside cylinder part 32 separated from the inside cylinder part 31 outwardly in a radial direction and arranged coaxially with the inside cylinder part 31; and a plurality of ribs 43 extending radially from the inside cylinder part 31 toward the outside cylinder part 32. The plurality of ribs 43 are arranged at regular intervals in a circumferential direction. A plurality of gate marks 35, indicating resin pouring positions, formed when the lens barrel 3A is molded are formed in one of the inside cylinder part 31 and the outside cylinder part 32, in the lens barrel 3A. Distances to the closest gate marks 35 from the ribs 43 are equal to each other.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a lens unit, and more particularly to a lens unit in which a camera lens is held by a lens barrel.

  A lens unit is known that includes a plurality of lenses and a lens barrel that holds the plurality of lenses, and at least one of the plurality of lenses is pressed and held on the inner peripheral surface of the lens barrel (Patent Document 1).

JP 2011-59396 A

    In recent years, there has been an increasing demand for higher resolution in the lens unit market. In order to obtain a higher resolution, the accuracy when the lens is held in the lens barrel is important. Therefore, the roundness accuracy of the inner peripheral surface of the lens barrel becomes important.

  Accordingly, the problem to be solved by the present invention is to provide a lens unit in which the roundness of the inner peripheral surface of the lens barrel is improved.

  In order to solve the above-described problem, a lens unit according to the present invention includes a plurality of lenses and a resin lens barrel in which the plurality of lenses are accommodated, and the lens barrel includes an inner cylindrical portion and the inner side. A plurality of ribs extending radially from the inner cylinder part toward the outer cylinder part, the outer cylinder part being arranged radially outward from the cylinder part and coaxially with the inner cylinder part; The ribs are arranged at equal intervals in the circumferential direction, and in the lens barrel, a gate mark indicating a resin injection position formed when the lens barrel is molded has the inner cylindrical portion and the outer cylindrical portion. The gist is that the distance from each rib to the nearest gate mark is the same.

  In the present invention, the distance from each rib to the nearest gate mark is equal, and the flow direction of the resin in each rib is the same. And each rib is arrange | positioned at equal intervals in the circumferential direction. For this reason, the roundness of the inner peripheral surface of the inner cylinder part can be improved. Further, since the space between the inner cylinder portion and the outer cylinder portion functions as a thinning, sink marks are suppressed, and the dimensional accuracy and shape accuracy are improved. Furthermore, since the inner cylindrical portion is reinforced by the plurality of ribs, the strength of the inner cylindrical portion is ensured. Moreover, resonance of the inner cylinder part by the vibration from the outside is also suppressed by the plurality of ribs.

  In the present invention, in the lens barrel, it is preferable that the number of ribs and the number of gate marks are three or more, respectively. According to this configuration, the roundness of the inner peripheral surface of the inner cylinder part is further improved.

  In the present invention, in the lens barrel, the number of ribs and the number of gate marks are preferably equal. According to this structure, the flow direction of the resin in each rib can be made the same.

  In the present invention, when the number of ribs and the number of gate marks are equal, each gate mark is preferably formed on a straight line connecting the optical axis and each rib. According to this structure, the flow direction of the resin in each rib can be made the same.

  In the present invention, in the lens barrel, the number of ribs is twice the number of gate marks, and each gate mark is separated from the nearest two ribs in either the inner cylinder part or the outer cylinder part. You may form in the position where distance is equal. Increasing the number of gate marks along with the number of ribs makes the mold structure more complex. According to such a configuration, even if the number of ribs increases, the flow direction of the resin in each rib can be made the same without complicating the mold structure.

  In the present invention, the plurality of gate marks may be formed on the outer cylinder portion. According to such a configuration, since no gate mark is formed on the inner cylinder portion, the roundness of the inner peripheral surface of the inner cylinder portion is further improved.

  In the present invention, the plurality of gate marks may be formed in the inner cylinder portion.

  In this invention, it is preferable that the thickness of the said inner cylinder part, the said outer cylinder part, and the said rib is equal. According to this configuration, when the lens barrel is molded, a decrease in dimensional accuracy due to resin sink marks is suppressed, and the roundness of the inner peripheral surface of the inner cylinder portion is improved.

  In the present invention, the inner cylinder part and the outer cylinder part are connected by the resin over the entire circumferential direction on the object side, and the thickness of the connection part is the thickness of the inner cylinder part and the outer cylinder part. Preferably they are equal. According to this configuration, when the lens barrel is molded, a decrease in dimensional accuracy due to resin sink marks is suppressed, and the roundness of the inner peripheral surface of the inner cylinder portion is improved.

  In the present invention, it is preferable that the plurality of ribs are disposed on a radially outer side of a position where at least one of the plurality of lenses is press-fitted. There is a high demand for the roundness of the inner peripheral surface of the inner cylindrical portion at the position where the lens is press-fitted, but according to such a configuration, the roundness of the inner peripheral surface of the inner cylindrical portion at the position where the lens is pressed-in high.

  In the present invention, a plurality of ridges extending along the optical axis direction are formed at equal intervals in the circumferential direction on the inner peripheral surface of the inner cylindrical portion, and the distance from each rib to its nearest ridge is Preferably they are equal. In order to hold the lens stably, it is preferable to have a protrusion on the inner peripheral surface of the inner cylinder part, but if the roundness of the inner peripheral surface of the inner cylinder part is low, the lens cannot be held stably. . According to such a configuration, since the roundness of the inner circle formed by connecting the tips of the protrusions is increased, the lens is stably held by having the protrusions on the inner peripheral surface of the inner cylindrical portion. be able to.

  In the present invention, on the radially outer side of the outer cylindrical portion, a flange portion that protrudes radially outward from the outer peripheral surface of the outer cylindrical portion is formed in a quadrangular shape in a plan view, and with respect to the symmetry axis of the rectangular shape. It is preferable that the plurality of ribs are arranged at symmetrical positions, and the plurality of gate marks are arranged at symmetrical positions. When the lens barrel has a collar part, the resin also flows in the collar part. There is a risk of sink marks on the outer cylinder part and the inner cylinder part due to the flow of the resin to the collar part. According to such a configuration, since the plurality of ribs are arranged at the symmetrical positions and the plurality of gate marks are arranged at the symmetrical positions with respect to the quadratic symmetry axis when the collar portion is viewed in plan view, A decrease in the roundness of the inner peripheral surface of the inner cylinder portion can be suppressed. Moreover, this collar part can be utilized as a fixing | fixed part at the time of fixing a lens unit to a predetermined position.

  According to the lens unit of the present invention, the distance from each rib to the nearest gate mark is equal, and the flow direction of the resin in each rib is the same. And each rib is arrange | positioned at equal intervals in the circumferential direction. For this reason, the roundness of the inner peripheral surface of the inner cylinder part can be improved. Further, since the space between the inner cylinder portion and the outer cylinder portion functions as a thinning, sink marks are suppressed, and the dimensional accuracy and shape accuracy are improved. Furthermore, since the inner cylindrical portion is reinforced by the plurality of ribs, the strength of the inner cylindrical portion is ensured. Moreover, resonance of the inner cylinder part by the vibration from the outside is also suppressed by the plurality of ribs.

It is sectional drawing of the lens unit which concerns on 1st embodiment. It is sectional drawing of the lens barrel of the lens unit shown in FIG. It is the figure which showed the bottom face of the lens barrel typically, and has abbreviate | omitted and shown the 3rd crimp part 39 and the collar part 41. FIG. FIG. 3A is a lens barrel of the lens unit according to the first embodiment, and FIGS. 3B and 3C are modified examples thereof. It is an expanded sectional view of the seal part of the lens barrel shown in FIG. It is the figure which showed the bottom face of the lens barrel typically, and has abbreviate | omitted and shown the 3rd crimp part 39 and the collar part 41. FIG. Fig.5 (a) is a lens barrel of the lens unit which concerns on 2nd embodiment, FIG.5 (b) is the modification. It is sectional drawing of the lens unit which concerns on 3rd embodiment. It is the figure which showed the bottom face of the lens barrel typically, and has abbreviate | omitted and shown the 3rd crimping part 39. FIG. Fig.7 (a) is a lens barrel of the lens unit which concerns on 3rd embodiment, FIG.7 (b) is the modification. It is the figure which showed typically the bottom face of the lens barrel 3H which provides a protrusion on the inner peripheral surface of the inner cylinder part of 3 A of lens barrels, and has abbreviate | omitted and shown the 3rd crimping part 39 and the collar part 41. . It is an expanded sectional view of the modification of the seal part of a lens barrel. It is the figure which showed the bottom face of the lens barrel typically, and has abbreviate | omitted and shown the 3rd crimp part 39 and the collar part 41. FIG. FIG. 8 shows a lens barrel having eight ribs and four gate marks.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a sectional view of a lens unit according to the first embodiment of the present invention. 2 is a cross-sectional view of a lens barrel of the lens unit shown in FIG. FIG. 3 is a diagram schematically showing the bottom surface of the lens barrel, in which the third caulking portion 39 and the flange portion 41 are omitted. FIG. 3A is a lens barrel of the lens unit according to the first embodiment, and FIGS. 3B and 3C are modified examples thereof. 4 is an enlarged cross-sectional view of a seal portion of the lens barrel shown in FIG.

  The lens unit 1A according to the first embodiment of the present invention includes a plurality of lenses 2 and a lens barrel 3A in which the plurality of lenses 2 are accommodated, and the plurality of lenses 2 are accommodated in the lens barrel 3A. .

(Configuration of multiple lenses 2)
Each of the plurality of lenses 2 has a disk shape with a circular peripheral edge, and is arranged side by side coaxially to form a wide-angle lens as a whole. The plurality of lenses 2 become a first lens 21, a second lens 22, a third lens 23, a fourth lens 24, and a fifth lens 25 in order from the object side L1. The fifth lens 25 and the fourth lens 24 are cemented to form a cemented lens 26. The cemented lens 26 is disposed at the end of the image side L2, and the first lens 21 is disposed at the end of the object side L1. In the cemented lens 26, the fifth lens 25 is a lens having positive power, and the fourth lens 24 is a lens having negative power. The third lens 23 is a lens having a positive power, and the first lens 21 and the second lens 22 are lenses having a negative power. A diaphragm 5 is disposed between the fourth lens 24 and the third lens 23. A light shielding plate 6 is disposed between the third lens 23 and the second lens 22. Further, the infrared cut filter 4 is disposed on the image side L2 relative to the cemented lens 26 disposed on the end of the image side L2. Since the plurality of lenses 2 are accommodated in the lens barrel 3 from the object side L1, the outer diameters of the first lens 21, the second lens 22, the third lens 23, the fourth lens 24, and the fifth lens 25 are in this order. The fifth lens 25 has the smallest outer diameter, and the first lens 21 has the largest outer diameter. The first to fifth lenses 21 to 25 are each made of a glass lens or a plastic lens. In this configuration, the first to fourth lenses are made of plastic, and the fifth lens is made of glass.

(Configuration of lens barrel 3A)
The lens barrel 3A includes a lens chamber S in which a plurality of lenses 2 are accommodated. The lens chamber S includes a first lens chamber S1 in which the first lens 21 is accommodated, a second lens chamber S2 in which the second lens 22 and the third lens 23 are accommodated, and a third lens 24 in which the fourth lens 24 is accommodated. The lens chamber S3 is divided into a fourth lens chamber S4 in which the fifth lens 25 is accommodated, and the first to fourth lens chambers S1 to S4 are connected in the direction of the optical axis L.

  The fourth lens chamber S4 has an inner diameter larger than the outer diameter of the fifth lens 25, and is partitioned by a first inner wall surface 311 of the cylindrical portion 30 that is continuous in the circumferential direction. The third lens chamber S3 has an inner diameter larger than the outer diameter of the fourth lens 24, and is partitioned by a second inner wall surface 312 of the cylindrical portion 30 that is continuous in the circumferential direction. The second lens chamber S2 has an inner diameter larger than the outer diameters of the third lens 23 and the second lens 22, and is partitioned by a third inner wall surface 313 of the cylindrical portion 30 that is continuous in the circumferential direction. The first lens chamber S <b> 1 has an inner diameter larger than the outer diameter of the first lens 21, and is partitioned by a fourth inner wall surface 314 of the cylindrical portion 30 that is continuous in the circumferential direction.

  At the end of the first inner wall surface 311 on the image side L2, a projecting portion 36 is formed projecting radially inward over the entire circumferential direction, and an opening for an optical path is formed at the center of the projecting portion 36. The part 36a is formed in a circular shape. On the image side L2 of the opening 36a, the infrared cut filter 4 is disposed so as to close the opening 36a. A third crimping portion 39 for crimping the peripheral end portion of the arranged infrared cut filter 4 from the image side L2 on the end surface of the cylindrical portion 30 on the image side L2 is projected to the image side L2 around the opening 36a. It is formed as follows.

  Between the end portion on the object side L1 of the first inner wall surface 311 and the end portion on the image side L2 of the second inner wall surface 312 of the third lens chamber S3 having an inner diameter larger than that of the fourth lens chamber S4 over the entire circumferential direction. The first step surface 315 extending in the radial direction is connected, and the first step surface 315 is a surface that supports the end of the fourth lens 24 on the image side L2. A first pressing portion 317 is formed at the end on the image side L2 of the second inner wall surface 312 so as to protrude radially inward over the entire circumferential direction. The inner diameter of the first pressing portion 317 is designed to be the same as or slightly larger than the outer diameter of the fourth lens 24, but the variation in the outer diameter in the circumferential direction of the fourth lens 24 and the circumferential direction of the first pressing portion 317. Due to the variation in the inner diameter, there is a portion where the outer diameter of the fourth lens 24 is slightly larger than the inner diameter of the first pressing portion 317, and thereby the first pressing portion 317 is hardly deformed. When the fourth lens 24 is lightly pressed, the fourth lens 24 is lightly pressed into the third lens chamber S3.

  A second pressing portion 318 is formed at the end on the image side L2 of the third inner wall surface 313 so as to project radially inward over the entire circumferential direction. The inner diameter of the second pressing portion 318 is designed to be the same as or slightly larger than the outer diameter of the third lens 23, but the variation in the outer diameter in the circumferential direction of the third lens 23 and the circumferential direction of the second pressing portion 318. Due to the variation in the inner diameter, there is a portion where the outer diameter of the third lens 23 is slightly larger than the inner diameter of the second pressing portion 318, so that the second pressing portion 318 is hardly deformed. When the third lens 23 is lightly pressed, the third lens 23 is lightly pressed into the third lens chamber S3. The inner wall surface of the second pressing portion 318 is connected to the end portion on the object side L1 of the second inner wall surface 312 of the third lens chamber S3 having an inner diameter smaller than that of the second lens chamber S2 over the entire circumferential direction. Yes.

  Between the end portion on the object side L1 of the third inner wall surface 313 and the end portion on the image side L2 of the fourth inner wall surface 314 of the first lens chamber S1 having an inner diameter larger than that of the second lens chamber S2, over the entire circumferential direction. The second step surfaces 316 extending in the radial direction are connected. A first caulking portion 37 for caulking the peripheral end portion of the second lens 22 accommodated in the second lens chamber S2 from the object side L1 is stretched on the object side L1 at the radially inner end portion of the second step surface 316. It is formed to take out.

  A receiving portion 316a that receives the end surface on the image side L2 of the first lens 21 housed in the first lens chamber S1 is projected to the object side L1 over the entire circumferential direction at a position in the radial direction of the second step surface 316. Is formed. In the radial direction of the second step surface 316, a recess 316 b is formed between the receiving portion 316 a and the fourth inner wall surface 314, which is a portion where the O-ring 7 for preventing intrusion from water or the like is disposed, and in the circumferential direction It is formed throughout. A second caulking portion 38 for caulking the peripheral end portion of the first lens 21 accommodated in the first lens chamber S1 from the object side L1 is stretched to the object side L1 at the radially outer end portion of the second step surface 316. It is formed to take out. The inner wall surface of the second caulking portion 38 is a fourth inner wall surface 314.

  The lens barrel 3 </ b> A includes an inner cylinder part 31, an outer cylinder part 32, and a plurality of ribs 43. The outer cylinder portion 32 is disposed radially outside the inner cylinder portion 31 and coaxially with the inner cylinder portion 31. The inner cylinder part 31 and the outer cylinder part 32 are connected over the entire circumferential direction on the object side L1 by a connecting part 33 made of resin. The plurality of ribs 43 are arranged so as to extend radially from the inner cylindrical portion 31 toward the outer cylindrical portion 32. The end surface on the image side L2 of each rib 43 is located closer to the object side L1 than the end surfaces on the image side L2 of the outer cylindrical portion 32 and the inner cylindrical portion 31. Each rib 43 extends from the end surface on the image side L2 to the connecting portion 33 in the optical axis L direction.

  As shown in FIG. 3A, four ribs 43 are formed in the lens barrel 3A. With respect to the optical axis L, when the position of one rib 43 is 0 °, the other three ribs 43 are respectively 90 °, 180 °, and 270 ° positions (positions shifted by 90 ° at equal angles). The four ribs 43 are arranged at equal intervals in the circumferential direction. In the lens barrel 3A, four gate marks 35 indicating the injection position of the resin formed when the lens barrel 3A is molded are formed. That is, in the lens barrel 3A, the number of ribs 43 and the number of gate marks 35 are equal. Each gate mark 35 is in the outer cylinder portion 32 and is formed on a straight line connecting the optical axis L and each rib 43. In the lens barrel 3A, the distance from each rib 43 to the nearest gate mark 35 is equal.

  In the circumferential direction, a gap 34 between the ribs 43 is a groove 34 that is recessed from the end surface on the image side L2 to the object side L1. The radially inner wall surface 34a (the outer peripheral surface of the inner cylindrical portion 31) of the groove portion 34 is formed in parallel on the inner peripheral surface of the inner cylindrical portion 31 formed in a step shape over the entire circumferential direction and the entire optical axis L direction. The wall thickness of the inner cylinder part 31 is equal at any position in the optical axis L direction. Further, the radially outer wall surface 34b (the inner peripheral surface of the outer cylindrical portion 32) of the groove portion 34 is formed on the outer peripheral surface of the outer cylindrical portion 32 in parallel over the entire circumferential direction and the entire optical axis L direction. The thickness of the part 32 is equal at any position in the optical axis L direction. On the other hand, the inner peripheral surface of the inner cylindrical portion 31 and the outer peripheral surface of the outer cylindrical portion 32 are not parallel. For this reason, the groove width of the groove part 34 changes in the optical axis L direction. Moreover, the thickness of the inner cylinder part 31 and the thickness of the outer cylinder part 32 are equal at any position in the optical axis L direction. The thickness of the rib 43 is equal to the thickness of the inner cylinder portion 31 and the outer cylinder portion 32. Further, the thickness of the connecting portion 33 is equal to the thickness of the inner cylindrical portion 31 and the outer cylindrical portion 32.

  In the lens barrel 3 </ b> A, a thread groove 42 is formed on the outer peripheral surface of the outer cylindrical portion 32 from the end on the image side L <b> 2 toward the object side L <b> 1 over the entire circumferential direction. The screw groove 42 is for screwing and fixing the lens unit 1A in a predetermined place. Further, in the lens barrel 3 </ b> A, a flange 41 that protrudes radially outward from the outer peripheral surface is formed at the end on the object side L <b> 1 of the outer cylindrical portion 32 over the entire circumferential direction. The collar portion 41 is a portion that is positioned when the lens unit 1A is screwed into a predetermined place.

(Configuration of lens unit 1A)
The plurality of lenses 2 are accommodated in the lens chamber S of the lens barrel 3 as follows. First, the cemented lens 26 in which the fifth lens 25 and the fourth lens 24 are cemented is accommodated from the opening on the object side L1 of the cylindrical portion 30 of the lens barrel 3 with the fifth lens 25 as the image side L2. At this time, the fifth lens 25 is accommodated in the fourth lens chamber S4, and the fourth lens 24 is accommodated in the third lens chamber S3. Since the outer diameter of the fifth lens 25 is smaller than the inner diameter of the fourth lens chamber S4 defined by the first inner wall surface 311, the fifth lens 25 is not press-fitted into the first inner wall surface 311 in the fourth lens chamber S4. . On the other hand, the outer diameter of the fourth lens 24 is smaller than the inner diameter of the third lens chamber S3 defined by the second inner wall surface 312, but the first lens formed at the end of the second inner wall surface 312 on the image side L2. Since it is the same or slightly smaller than the inner diameter of the portion defined by the pressing portion 317, the fourth lens 24 is press-fitted into the first pressing portion 317 on the image side L2 in the third lens chamber S3. The fourth lens 24 is placed on the first step surface 315. Thereby, the cemented lens 26 is positioned in the radial direction and the optical axis L direction.

  Next, after the diaphragm 5 is disposed on the object side L1 of the fourth lens 24, the third lens 23 is disposed on the object side L1 of the fourth lens 24 with the diaphragm 5 interposed therebetween. The outer diameter of the third lens 23 is smaller than the inner diameter of the second lens chamber S2 defined by the third inner wall surface 313, but the second pressing portion formed at the end of the third inner wall surface 313 on the image side L2. Since the inner diameter of the portion defined by 318 is the same as or slightly smaller, the third lens 23 is press-fitted into the second pressing portion 318 on the image side L2 in the second lens chamber S2. Thereby, the third lens 23 is positioned in the radial direction and the optical axis L direction.

  Next, after the light shielding plate 6 is disposed on the object side L1 of the third lens 23, the second lens 22 is disposed on the object side L1 of the third lens 23 with the light shielding plate 6 interposed therebetween. Since the outer diameter of the second lens 22 is the same as or slightly smaller than the inner diameter of the second lens chamber S2 defined by the third inner wall surface 313, the second lens 22 is connected to the third inner wall surface in the second lens chamber S2. 313 is press-fitted. Further, after the radial position of the second lens 22 is adjusted, the peripheral end portion is crimped from the object side L1 by the first crimping portion 37 formed on the second step surface 316. Thereby, the second lens 22 is positioned in the optical axis L direction. Further, a pressing force acts on the third to fifth lenses 23 to 25, the diaphragm 5 and the light shielding plate 6 below the second lens 22 which has been crimped, and the third to fifth lenses 23 to 25 are caused by this pressing force. The diaphragm 5 and the light shielding plate 6 are positioned reliably. Since the second lens 22 is caulked at the peripheral end from the object side L1 by the first caulking portion 37, the second lens chamber S2 in which the outer diameter of the second lens 22 is partitioned by the third inner wall surface 313. It is good also as a structure which is made smaller and is not press-fitted.

  Next, after the O-ring 7 is disposed in the recess 316b of the second step surface 316, the first lens 21 is disposed in the first lens chamber S1. At this time, the first lens 21 is placed on the receiving portion 316 a formed on the second step surface 316. Since the outer diameter of the first lens 21 is smaller than the inner diameter of the first lens chamber S1 defined by the fourth inner wall surface 314, the first lens 21 is press-fitted into the fourth inner wall surface 314 in the first lens chamber S1. Not. After the position in the radial direction of the first lens 21 is adjusted, the peripheral end portion is crimped from the object side L1 by the second crimping portion 38 formed at the end portion of the cylindrical portion 30 on the object side L1. Thereby, the first lens 21 is positioned in the optical axis L direction. The O-ring 7 is compressed and sealed by the pressing force to the image side L2 at this time. Thereby, intrusion of water or the like from the outside is suppressed.

  In the lens barrel 3 </ b> A, as shown in FIG. 4, the receiving portion 316 a that receives the end surface of the fifth lens 25 on the image side L <b> 2 is radially inward from the position where the O-ring 7 is disposed. Then, the receiving portion 316a serves as a wall that suppresses the O-ring 7 from moving inward in the radial direction due to external pressure such as water pressure, and a decrease in airtightness and watertightness associated with the movement of the O-ring 7 is suppressed.

  In the lens unit 1 </ b> A, among the plurality of lenses 2, the fourth lens 24 and the third lens 23 are press-fitted into the lens chamber S of the cylindrical portion 30. The fourth lens 24 forms a cemented lens 26 together with the fifth lens 25. The fourth lens 24 is positioned in the radial direction by being press-fitted, but if the roundness of the lens chamber S (third lens chamber S3) of the cylindrical portion 30 is low at the press-fitted portion, Due to the eccentricity, the fourth lens 24 may be distorted and peeled off at the joint with the fifth lens 25. A diaphragm 5 is disposed between the fourth lens 24 and the third lens 23. The fourth lens 24 and the third lens 23 are positioned in the radial direction by being press-fitted. However, it is assumed that the lens chamber S (third lens chamber) of the cylindrical portion 30 is temporarily inserted into the fourth lens 24. If the roundness of S3) is low, the decentration between the fourth lens 24 and the third lens 23 will affect the optical characteristics. If the roundness of the lens chamber S (second lens chamber S2) of the cylindrical portion 30 is low at the portion where the third lens 23 is press-fitted, the eccentricity between the fourth lens 24 and the third lens 23 is assumed. As a result, the influence on the optical characteristics is increased. For this reason, the roundness of the lens chamber S of the cylindrical portion 30 at the press-fitted portion is particularly important.

(Main effects of this form)
In the present embodiment, in the lens barrel 3A, the number of ribs 43 and the number of gate marks 35 are equal, and each gate mark 35 is formed on a straight line connecting the optical axis L and each rib 43 in the outer cylindrical portion 32, respectively. Has been. Thereby, the distance from each rib 43 to the nearest gate mark 35 is equal. Then, as shown in FIG. 3A, the resin flows in the direction of the arrow from the gate position (same as the position of the gate mark 35) at the time of molding. It flows in the direction of the cylinder part 31. That is, the flow direction of the resin in each rib 43 is the same. In the position where the rib 43 is formed, the inner peripheral surface of the inner cylindrical portion 31 is similarly convex inward with respect to the position where the rib 43 is not formed. Since each rib 43 is arrange | positioned at equal intervals in the circumferential direction, the internal peripheral surface of the inner side cylinder part 31 has a convex surface at equal intervals in the circumferential direction.

  On the other hand, as shown in FIG. 10, regarding the lens barrel 3I in which the number of ribs 43 is eight and the number of gate marks 35 is four, each gate mark 35 has an optical axis L at the outer cylindrical portion 32. The number of ribs 43 and the number of gate marks 35 are not equal. For this reason, the distance from each rib 43 to the nearest gate mark 35 is not equal. In this case, since the resin flows in the direction of the arrow from the gate position (same as the position of the gate mark 35) at the time of molding, the rib 43 (431) having the gate mark 35 on the straight line connecting the optical axis L and each rib 43. Then, the resin flows from the outer cylindrical portion 32 toward the inner cylindrical portion 31. However, in the rib 43 (432) having no gate mark 35 on the straight line connecting the optical axis L and each rib 43, the resin also flows in the direction from the inner cylindrical portion 31 to the outer cylindrical portion 32. That is, the flow direction of the resin in each rib 43 is not the same. For this reason, at the position of the rib 43 (432) where the gate mark 35 does not exist on the straight line connecting the optical axis L and each rib 43, sink marks occur in the inner cylindrical portion 31, and the position where the rib 43 is not formed is used as a reference. The inner peripheral surface of the inner cylindrical portion 31 is similarly concave. On the other hand, at the position of the rib 43 (431) where the gate mark 35 is on the straight line connecting the optical axis L and each rib 43, the inner circumference of the inner cylinder portion 31 is based on the position where the rib 43 is not formed. Each surface is similarly convex inward. That is, in the case of the lens barrel 3I shown in FIG. 10, a concave surface and a convex surface are formed on the inner peripheral surface of the inner cylindrical portion 31 with reference to the position where the rib 43 is not formed.

  Then, in the present embodiment shown in FIG. 3A, the unevenness difference of the inner peripheral surface of the inner cylindrical portion 31 is small as compared with the embodiment shown in FIG. That is, since the flow direction of the resin in each rib 43 is the same, the unevenness difference of the inner peripheral surface of the inner cylinder part 31 is small, so that the roundness can be improved.

  Further, in the present embodiment, the outer cylindrical portion 32 is arranged radially outside the inner cylindrical portion 31 and coaxially with the inner cylindrical portion 31, and at a position where the rib 43 is not formed, A groove 34 that is recessed from the end surface on the image side L2 to the object side L1 is disposed between the inner cylinder portions 31. Since this groove part 34 functions as the thinning of the lens barrel 3A, sink marks are suppressed, and the dimensional accuracy and shape accuracy are improved. Moreover, in this embodiment, since the inner cylinder part 31 is reinforced with the some rib 43, the intensity | strength of the inner cylinder part 31 is ensured. Further, the plurality of ribs 43 can also suppress the resonance of the inner cylindrical portion 31 due to external vibration.

  In the present embodiment, since the number of ribs 43 and the number of gate marks 35 are three or more, the roundness of the inner peripheral surface of the inner cylindrical portion 31 is improved.

  Further, in the present embodiment, since the inner cylindrical portion 31, the outer cylindrical portion 32, and the ribs 43 are equal in thickness, a decrease in dimensional accuracy due to resin sink marks can be suppressed during molding of the lens barrel 3A. The roundness of the inner peripheral surface of the inner cylinder part 31 is improved. In the present embodiment, since the inner cylindrical portion 31, the outer cylindrical portion 32, and the connecting portion 33 have the same thickness, a decrease in dimensional accuracy due to resin sink marks can be suppressed when the lens barrel 3A is molded. The roundness of the inner peripheral surface of the inner cylinder part 31 is improved.

  Moreover, in this embodiment, the some rib 43 is arrange | positioned in the radial direction outer side of the position where the 2nd lens 22 of the some lenses 2 is press-fit, and the position where the 3rd lens 23 is press-fit. . As described above, at the position where the lens is press-fitted, there is a high demand for the roundness of the inner peripheral surface of the inner cylindrical portion 31, but in this embodiment, a plurality of radially outer sides of the position where the lens is press-fitted. Since the rib 43 is disposed, the roundness of the inner peripheral surface of the inner cylinder portion 31 is high at this position. Since the roundness is high at the position where the second lens 22 is press-fitted, the eccentricity between the second lens 22 and the first lens 21 is suppressed, and the separation at the joint portion of the cemented lens 26 is suppressed. Further, since the roundness is high at the position where the second lens 22 is press-fitted and the position where the third lens 23 is press-fitted, the eccentricity of the lenses arranged on both sides of the diaphragm 5 can be suppressed.

(Other embodiments)
Next, a lens unit according to a second embodiment of the present invention will be described. The lens unit according to the second embodiment differs from the lens unit according to the first embodiment in the number of ribs of the lens barrel. Since other configurations are the same as those of the lens unit according to the first embodiment, only different configurations will be described, and description of the same configurations will be omitted. Common parts are denoted by the same reference numerals.

  FIG. 5 is a diagram schematically showing the bottom surface of the lens barrel, in which the third caulking portion 39 and the flange portion 41 are omitted. Fig.5 (a) is a lens barrel of the lens unit which concerns on 2nd embodiment, FIG.5 (b) is the modification.

  As shown in FIG. 5A, eight ribs 43 are formed in the lens barrel 3D. When the position of one rib 43 with respect to the optical axis L is set to 0 °, the other seven ribs 43 are arranged at positions that are deviated by 45 ° at equal angles. Are arranged at equal intervals in the circumferential direction. On the other hand, there are four gate marks 35. That is, in the lens barrel 3D, the number of ribs 43 is twice the number of gate marks 35. Each gate mark 35 is in the outer cylinder portion 32 and is formed at an intermediate position between two adjacent ribs 43. That is, each gate mark 35 is formed in the outer cylinder part 32 at a position where the distance from the two nearest ribs 43 is equal. As a result, the distance from each rib 43 to the nearest gate mark 35 is equal.

  Then, as shown in FIG. 5A, since the resin flows in the direction of the arrow from the gate position (same as the position of the gate mark 35) at the time of molding, the resin is inward from the outer cylindrical portion 32 in each rib 43. It flows in the direction of the cylinder part 31. That is, the flow direction of the resin in each rib 43 is the same. In the position where the rib 43 is formed, the inner peripheral surface of the inner cylindrical portion 31 is similarly convex inward with respect to the position where the rib 43 is not formed. Since each rib 43 is arrange | positioned at equal intervals in the circumferential direction, the internal peripheral surface of the inner side cylinder part 31 has a convex surface at equal intervals in the circumferential direction.

  Therefore, the present embodiment shown in FIG. 5A has a smaller unevenness on the inner peripheral surface of the inner cylindrical portion 31 than the embodiment shown in FIG. 8, as in the embodiment shown in FIG. That is, since the flow direction of the resin in each rib 43 is the same, the unevenness difference of the inner peripheral surface of the inner cylinder part 31 is small, so that the roundness can be improved.

  In the present embodiment shown in FIG. 5A, the number of ribs 43 is larger than that in the embodiment shown in FIG. Specifically, it is 2 times. Also in the embodiment shown in FIG. 3A, if the number of the ribs 43 is increased, the unevenness on the inner peripheral surface of the inner cylindrical portion 31 becomes a finer pitch. Can be kept smaller. However, in the embodiment shown in FIG. 3A, the number of ribs 43 and the number of gate marks 35 are the same. Increasing the number of gates (same as the number of gate marks 35) in accordance with the number of ribs 43 makes the mold structure more complicated. On the other hand, in the present embodiment shown in FIG. 5A, the number of ribs 43 is twice the number of gate marks 35. If it does so, even if the number of the ribs 43 increases, the flow direction of the resin in each rib 43 can be made the same, without complicating a metal mold | die structure. That is, even when the number of ribs 43 is increased, the inner cylindrical portion 31 having a high roundness of the inner peripheral surface can be obtained as in the embodiment shown in FIG. 3A without complicating the mold structure.

  Next, a lens unit according to a third embodiment of the present invention will be described. The lens unit according to the third embodiment is different from the lens unit according to the second embodiment in that a thread groove is not formed in the position of the flange portion and the outer peripheral surface of the outer cylindrical portion. Since other configurations are the same as those of the lens unit according to the second embodiment, only different configurations will be described, and description of the same configurations will be omitted. Common parts are denoted by the same reference numerals.

  FIG. 6 is a sectional view of a lens unit according to the third embodiment of the present invention. FIG. 7 is a diagram schematically showing the bottom surface of the lens barrel, in which the third caulking portion 39 is omitted. Fig.7 (a) is a lens barrel of the lens unit which concerns on 3rd embodiment, FIG.7 (b) is the modification.

  As shown in FIG. 6, in the lens barrel 3 </ b> F of the lens unit 1 </ b> F according to the third embodiment, a flange portion 44 projecting radially outward from the outer peripheral surface of the outer cylindrical portion 32 is provided at the end on the image side L <b> 2. It is formed over the entire direction. The flange portion 44 can be used as a fixing portion when the lens unit 1F is fixed at a predetermined position.

  As shown in FIG. 7A, the flange portion 44 is formed in a quadrangular shape in plan view. The quadrangle has an axis of symmetry represented by two centerlines P and H. The eight ribs 43 are arranged at symmetrical positions with respect to the symmetry axis composed of one center line P. Further, the four gate marks 35 are arranged at symmetrical positions with respect to the symmetry axis composed of one center line P. Further, the eight ribs 43 are arranged at symmetrical positions with respect to the symmetry axis composed of the other center line H. Further, the four gate marks 35 are arranged at symmetrical positions with respect to the symmetry axis composed of the other center line H.

  In the lens barrel 3F, a flange portion 44 that extends radially outward from the outer peripheral surface of the outer cylindrical portion 32 is formed at the end portion on the image side L2 over the entire circumferential direction. The resin flows. The flow of the resin to the flange part 44 may cause the sink effect on the outer cylinder part 32 and the inner cylinder part 31. According to the lens barrel 3F, a plurality of ribs 43 are arranged at symmetrical positions with respect to a quadratic symmetry axis (center lines P, H) when the flange portion 44 is viewed in plan, and a plurality of gate marks 35 are formed. Since it arrange | positions in the symmetrical position, the fall of the roundness of the internal peripheral surface of the inner side cylinder part 31 by sink can be suppressed.

  As mentioned above, although embodiment of this invention was described in detail, this invention is not limited to the said embodiment at all, A various change is possible in the range which does not deviate from the summary of this invention.

  For example, in FIG. 3A, the lens barrel 3A having four ribs 43 and four gate marks 35 is shown. However, if the number of ribs 43 and gate marks 35 is the same, the number is particularly limited. It is not something. For example, the number of ribs 43 may be eight and the number of gate marks 35 may be eight. 5A shows the lens barrel 3D having eight ribs 43 and four gate marks 35. However, if the number of ribs 43 is twice the number of gate marks 35, the number thereof will be described. Is not particularly limited. For example, six ribs 43 and three gate marks 35 may be provided. As the number of the ribs 43 and the gate marks 35 increases, the pitch of the unevenness on the inner peripheral surface of the inner cylindrical portion 31 becomes finer, so that the roundness can be further increased. When the number of the ribs 43 and the gate marks 35 is 3 or more, the effect of increasing the roundness is high.

  In FIG. 3A, the number of ribs 43 and gate marks 35 are the same, and each gate mark 35 is formed on a straight line connecting the optical axis L and each rib 43. In the case where the number of 35 is the same, each gate mark 35 may not be formed on a straight line connecting the optical axis L and each rib 43.

  For example, as in the lens barrel 3 </ b> B shown in FIG. 3B, each gate mark 35 is in the outer cylinder portion 32 and may be formed at an intermediate position between two adjacent ribs 43. Also in the lens barrel 3B, the distance from each rib 43 to the nearest gate mark 35 is equal. As a result, the flow direction of the resin in each rib 43 is the same.

  For example, as in the lens barrel 3C shown in FIG. 3C, each gate mark 35 is located on the outer cylindrical portion 32, and one of the two ribs 43 is disposed between two adjacent ribs 43. It may be formed at a position close to. In this case, the four gate marks 35 are arranged at positions that are shifted by 90 ° in the circumferential direction at equal angles, and are arranged at equal intervals in the circumferential direction. Also in the lens barrel 3C, the distance from each rib 43 to the nearest gate mark 35 is equal. As a result, the flow direction of the resin in each rib 43 is the same.

  For example, in the lens barrel 3 </ b> D shown in FIG. 5A, each gate mark 35 is in the outer cylinder part 32, but each gate mark 35 may be in the inner cylinder part 31. Like the lens barrel 3 </ b> E shown in FIG. 5B, each gate mark 35 is in the inner cylinder portion 31 and may be formed at an intermediate position between two adjacent ribs 43. Also in the lens barrel 3E, the distance from each rib 43 to the nearest gate mark 35 is equal.

  In the lens barrel 3E, as shown in FIG. 5B, the resin flows in the direction of the arrow from the gate position (same as the position of the gate mark 35) at the time of molding. It flows from 31 to the direction of the outer cylinder part 32. That is, the flow direction of the resin in each rib 43 is the same. At this time, in the inner cylinder portion 31, the position where the gate mark 35 is formed and the position where the gate mark 35 is not formed are different in resin flow during molding, but the position where the gate mark 35 is not formed. Since the resin flows from the gate positions on both sides thereof, the position where the gate marks 35 are not formed does not become so large as compared with the position where the gate marks 35 are formed. Therefore, even in this case, the roundness is high because the unevenness difference of the inner peripheral surface of the inner cylindrical portion 31 is small as compared with the embodiment shown in FIG.

  Similarly to the lens barrel 3E shown in FIG. 5B, in the lens barrels 3A to 3C shown in FIGS. 3A to 3C, the position of each gate mark 35 is changed from the outer cylindrical portion 32 to the inner cylindrical portion 31. You may change to In other words, when the number of ribs 43 and the number of gate marks 35 is the same, each gate mark 35 is in the inner cylinder portion 31, and each gate mark 35 is formed on a straight line connecting the optical axis L and each rib 43. Alternatively, it may be formed at an intermediate position between two adjacent ribs 43, or formed at a position near one of the two ribs 43 between the two adjacent ribs 43. It may be.

  In addition, the formation position of each gate mark 35 is more preferable in the outer cylinder part 32 than in the inner cylinder part 31. When each gate mark 35 is formed in the inner cylinder part 31, as described above, the position where the gate mark 35 is not formed in the inner cylinder part 31 as compared with the position where the gate mark 35 is formed. In contrast, the inner peripheral surface of the inner cylindrical portion 31 tends to be concave, whereas when each gate mark 35 is formed in the outer cylindrical portion 32, such a situation does not occur. This is because the roundness of the inner peripheral surface of the inner cylindrical portion 31 is increased when the outer cylindrical portion 32 is formed.

  Further, for example, in the lens barrel 3G shown in FIG. 7A, the two center lines P and H of the flange portion 44 formed in a quadrangular shape in plan view are used as symmetry axes, but the two diagonal lines D1 of the quadrangular shape are used. , D2 may be the axis of symmetry. In this case, the flange portion 44 is formed in a regular square shape in plan view. In the lens barrel 3G, the eight ribs 43 are arranged at symmetrical positions with respect to the symmetry axis formed by one diagonal line D1. Further, the four gate marks 35 are arranged at symmetrical positions with respect to the symmetry axis formed by one diagonal line D1. Further, the eight ribs 43 are arranged at symmetrical positions with respect to the symmetry axis composed of another diagonal line D2. Further, the four gate marks 35 are arranged at symmetrical positions with respect to the symmetry axis composed of another diagonal line D2. According to the lens barrel 3G, the plurality of ribs 43 are arranged at symmetrical positions and the plurality of gate marks 35 are symmetric with respect to a quadratic symmetry axis (diagonal lines D1, D2) when the flange portion 44 is viewed in plan. Since it arrange | positions in the position, the fall of the roundness of the internal peripheral surface of the inner side cylinder part 31 by sink can be suppressed.

  As shown in the lens barrel 3 </ b> H shown in FIG. 8, the inner peripheral surface (for example, the position where the rib 43 is disposed) of the inner cylindrical portion 31 has a plurality of protrusions 45 extending along the optical axis L direction. It may be formed at equal intervals in the direction. The protrusion 45 is for reducing lens distortion caused by pressure input when the lens is press-fitted. The protrusions are different from the unevenness formed by the flow of the resin at the time of molding, and are protrusions that are transferred and formed on the inner peripheral surface of the inner cylindrical portion 31 by the recesses formed in advance on the mold surface of the mold. In this case, the distance from each rib 43 to the nearest ridge 45 may be equal. In order to hold the lens stably, it is preferable to have a protrusion 45 on the inner peripheral surface of the inner cylindrical portion 31, but when the roundness of the inner peripheral surface of the inner cylindrical portion 31 is low, the lens is stabilized. Can not be held. According to this configuration, since the roundness of the inner circle formed by connecting the tips of the protrusions 45 is increased, the lens is stably provided by having the protrusions on the inner peripheral surface of the inner cylindrical portion 31. Can be held. In FIG. 8, the lens barrel 3 </ b> A shown in FIG. 3A has protrusions 45 on the inner peripheral surface of the inner cylindrical portion 31, but the inner cylindrical portion 31 is also used in the lens barrels 3 </ b> B to 3 </ b> G, for example. It may have a ridge 45 on the inner peripheral surface.

  Further, for example, in the lens barrel 3A shown in FIG. 1, as shown in FIG. 4, the receiving portion 316a that receives the end surface on the image side L2 of the fifth lens 25 is located radially inward from the position where the O-ring 7 is disposed. However, as in the modified example of the seal portion shown in FIG. 9, the receiving portion 316 a that receives the end surface on the image side L <b> 2 of the fifth lens 25 may be located radially outside the position where the O-ring 7 is disposed. . In addition, the sealing part shown in FIG. 4 can improve airtightness and watertightness further compared with the sealing part shown in FIG.

1A, 1F Lens unit 2 Multiple lenses 21 1st lens 22 2nd lens 23 3rd lens 24 4th lens 25 5th lens 26 Joint lens 3A-3F Lens barrel 5 Aperture 6 Light shielding plate 7 O-ring 31 Inner cylinder part 32 Outer cylinder portion 33 Connecting portion 34 Groove portion 34a Radially inner wall surface 34b Groove portion radially outer wall surface 35 Gate mark 36 Support portion 36a Opening portion 37 First caulking portion 38 Second caulking portion 39 Third caulking Portion 311 First inner wall surface 312 Second inner wall surface 313 Third inner wall surface 314 Fourth inner wall surface 315 First step surface 316 Second step surface 316a Receiving portion 316b Recessed portion 317 First pressing portion 318 Second pressing portion 41 Gutter portion 42 Thread groove 43 Rib 44 ridge 45 ridge L optical axis P, H center line D1, D2 diagonal L1 object side L2 image side S lens chamber S1 first lens chamber S2 second lens Chamber S3 third lens chamber S4 fourth lens chamber

Claims (12)

Multiple lenses,
A resin lens barrel containing the plurality of lenses;
Have
The lens barrel includes an inner cylindrical portion, an outer cylindrical portion arranged radially outward from the inner cylindrical portion, and coaxially arranged with the inner cylindrical portion, and radially from the inner cylindrical portion toward the outer cylindrical portion. A plurality of extending ribs,
The plurality of ribs are arranged at equal intervals in the circumferential direction,
In the lens barrel, a plurality of gate marks indicating the injection position of the resin formed when the lens barrel is molded are formed on either the inner cylinder part or the outer cylinder part,
A lens unit characterized in that the distance from each rib to the nearest gate mark is equal.   2. The lens unit according to claim 1, wherein in the lens barrel, the number of ribs and the number of gate marks are each 3 or more.   3. The lens unit according to claim 1, wherein the number of ribs and the number of gate marks are equal in the lens barrel.   4. The lens unit according to claim 3, wherein each gate mark is formed on a straight line connecting the optical axis composed of the plurality of lenses and each rib. 5.   In the lens barrel, the number of ribs is twice the number of gate marks, and each gate mark is located at the same distance from the nearest two ribs in either the inner cylinder part or the outer cylinder part. The lens unit according to claim 1, wherein the lens unit is formed.   The lens unit according to claim 1, wherein the plurality of gate marks are formed in the outer cylinder portion.   The lens unit according to claim 1, wherein the plurality of gate marks are formed in the inner cylinder portion.   The lens unit according to any one of claims 1 to 7, wherein the inner cylinder part, the outer cylinder part, and the rib have equal thicknesses.   The inner cylinder part and the outer cylinder part are connected by the resin over the entire circumferential direction on the object side, and the thickness of the connection part is equal to the thickness of the inner cylinder part and the outer cylinder part. The lens unit according to claim 1, wherein the lens unit is a lens unit.   The said some rib is arrange | positioned in the radial direction outer side of the position in which the at least 1 lens of the said some lens is press-fit, The any one of Claim 1 to 9 characterized by the above-mentioned. Lens unit.   A plurality of ridges extending along the optical axis direction are formed at equal intervals in the circumferential direction on the inner peripheral surface of the inner cylindrical portion, and the distance from each rib to the nearest ridge is equal. The lens unit according to any one of claims 1 to 10, wherein:   On the radially outer side of the outer cylindrical portion, a flange portion that protrudes radially outward from the outer peripheral surface of the outer cylindrical portion is formed in a quadrangular shape in plan view, and the plurality of the symmetric axes with respect to the rectangular symmetry axis. The lens unit according to any one of claims 1 to 11, wherein the rib is disposed at a symmetric position, and the plurality of gate marks are disposed at a symmetric position.

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