Lens unit

Abstract

To provide a lens unit configured so that a lens with a heater unit of a flexible printed board can be easily embedded in a lens barrel.SOLUTION: A lens unit 1 includes: a lens barrel 20 comprising a first cylinder 21 holding a first lens 11, a second cylinder 22 holding a second lens 12, and an annular connection unit 24 connecting the first cylinder 21 and the second cylinder 22; an annular elastic member 40; and a flexible printed board 30 comprising an annular part 31 having an annular heater unit 35 and an extension part 32 extending from the annular part 31. The connection unit 24 includes: an annular positioning section 26 coming into contact with a flange surface 115 of the first lens 11; an annular groove section 27 formed radially outside the positioning section 26; and a through hole 28 formed radially inside the positioning section 26. The elastic member 40 is arranged in the groove section 27. The annular part 31 comes into contact with the flange surface 115 of the first lens 11. The extension part 32 penetrates through the through hole 28.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a lens unit capable of suppressing condensation generated inside a lens barrel.

[0002] The lens unit used in an optical device is described in Patent Document 1. The lens unit in this document includes a first lens disposed on the most object side, a second lens disposed on the image side with respect to the first lens, a lens barrel that houses the first lens and the second lens, and an O-ring disposed between the first lens and the lens barrel. Further, the lens unit includes a flexible printed circuit board having a heater portion for suppressing the occurrence of condensation inside the lens barrel when used outdoors.

[0003] The lens barrel includes a large-diameter portion that houses the first lens, a medium-diameter portion that houses the second lens, and a connecting portion that connects the large-diameter portion and the medium-diameter portion. The O-ring is disposed between the surface facing the outer side in the radial direction of the first lens and the inner peripheral surface of the large-diameter portion. The flexible printed circuit board includes an annular plate-like portion provided with a heater portion and an extending portion extending radially from the plate-like portion. The plate-like portion is adhered to the flange surface facing the image side of the first lens. The extending portion passes through a through-hole penetrating the connecting portion in the optical axis direction and is drawn out to the image side. The through-hole overlaps the O-ring in the optical axis direction.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the lens unit described above, when assembling the first lens into the lens barrel, the O-ring is held on the radially outward-facing surface of the first lens. Furthermore, the plate-like portion of the flexible printed circuit board is bonded to the flange surface of the first lens with adhesive, and the extended portion of the flexible printed circuit board extends to a position close to the O-ring. Moreover, the through-hole through which the extended portion passes and the O-ring overlap in the optical axis direction. Therefore, assembling the first lens into the lens barrel while passing the extended portion through the through-hole is not easy.

[0006] In view of the above problems, the object of the present invention is to provide a lens unit that allows for easy assembly of a lens, to which a heater portion of a flexible printed circuit board is attached, into a lens barrel, while passing the stretched portion of the flexible printed circuit board through a through hole provided in the lens barrel. [Means for solving the problem]

[0007] To solve the above problems, the lens unit of the present invention comprises a first lens located closest to the object in the optical axis direction along the optical axis, a second lens located on the image side of the first lens, a resin lens barrel having a first cylindrical portion that holds the first lens, a second cylindrical portion having a smaller outer diameter than the first cylindrical portion and housing the second lens, and an annular connecting portion that connects the first cylindrical portion and the second cylindrical portion radially, an annular elastic member that seals the space between the first lens and the lens barrel, an annular portion having an annular heater portion, and a flexible printed circuit board having an extended portion extending outward from the annular portion, wherein the first lens has an object-side lens surface, an image-side lens surface, and an image-side flange surface surrounding the image-side lens surface, and the connecting portion has an annular positioning portion that abuts the image-side flange surface and positions the first lens in the optical axis direction. The positioning portion comprises an annular groove portion for housing the elastic member on the radially outer side of the positioning portion, and a through hole on the radially inner side of the positioning portion that penetrates a portion of the circumferential direction of the connecting portion in the direction of the optical axis, wherein the annular portion contacts the image-side flange surface on the radially inner side of the positioning portion, and the extended portion is pulled out to the image side of the connecting portion through the through hole.

[0008] According to the present invention, the heater portion of the flexible printed circuit board contacts the image-side flange surface of the first lens. Therefore, the temperature of the image-side of the first lens can be increased by energizing the heater portion. Thus, condensation in the space between the first lens and the second lens, which would otherwise degrade optical performance, can be suppressed. Furthermore, the elastic member is positioned in a groove facing the first lens from the optical axis direction. Therefore, compared to the case where the elastic member is positioned radially between the first lens and the first barrel, the first lens is easier to hold in the first barrel. Moreover, the extended portion of the flexible printed circuit board passes through a through-hole provided on the radially inner side of the positioning portion. Therefore, the positioning portion is interposed between the elastic member and the flexible printed circuit board in the radial direction. Thus, when assembling the first lens with the flexible printed circuit board attached into the lens barrel, the elastic member and the extended portion of the flexible printed circuit board do not interfere with each other. Therefore, it becomes easier to assemble the first lens into the first barrel of the lens barrel.

[0009] In the present invention, the connecting portion may have a recess on the surface facing the image side that is recessed toward the object side, a through hole opening in the recess, and the extended portion may be fixed to the connecting portion by a sealing member filled in the recess. In this way, the extended portion of the flexible printed circuit board that passes through the through hole of the connecting portion can be fixed to the connecting portion.

[0010] In the present invention, the opening edge of the through hole in the connecting portion comprises a first opening edge portion extending linearly in the circumferential direction, a second opening edge portion extending parallel to the first opening edge portion on the outer circumference side of the first opening edge portion, a third opening edge portion connecting one circumferential end of the first opening edge portion to one circumferential end of the second opening edge portion, and a fourth opening edge portion connecting the other circumferential end of the first opening edge portion to the other circumferential end of the second opening edge portion, and the outer circumferential surface of the second cylindrical portion may be provided with a planar portion extending from the first opening edge portion in the direction of the optical axis toward the image side. In this way, the extended portion that has passed through the through hole and been drawn out from the object side to the image side of the connecting portion can be routed along the planar portion.

[0011] In the present invention, the inner circumferential surface of the second cylindrical portion is provided with a plurality of ribs extending in the direction of the optical axis, the plurality of ribs abut the second lens from the outer circumferential side to position the second lens radially, and one of the plurality of ribs is provided at a position that overlaps with the planar portion when viewed from a direction perpendicular to the optical axis. In this way, the thickness of the portion of the second cylindrical portion where the planar portion is provided can be increased. As a result, the difference in thickness between the portion of the second cylindrical portion where the planar portion is provided and the portion where it is not provided can be reduced, thereby suppressing the occurrence of molding defects in the second cylindrical portion when molding a resin lens barrel.

[0012] In the present invention, an annular crimping portion is provided at the object-side end of the second cylindrical portion, and the crimping portion comprises an annular portion having a tapered surface portion that slopes inward toward the object-side on an outer peripheral surface facing radially outward, and a bent portion that bends radially inward from the object-side end of the annular portion and contacts the outer peripheral edge of the second lens from the object side, and a space is provided between the radial positioning portion and the tapered surface portion, and the image-side end of the tapered surface portion can be positioned closer to the image than the object-side end of the rib. In this way, when holding the second lens in the second cylindrical portion, a jig can be inserted into the space provided radially outward of the annular portion to perform crimping, and the portion of the annular portion located on the object side can be bent inward to become the contact portion. Since the image-side end of the rib overlaps with the object-side end of the rib in a direction perpendicular to the optical axis, even if a tapered surface is provided in the annular portion, it is possible to suppress the thinning of the annular portion. Therefore, it is possible to suppress the occurrence of molding defects in the crimped portion when forming the lens barrel.

[0013] In the present invention, the positioning portion may overlap with a part of the second cylindrical portion when viewed from the optical axis direction. In this way, when assembling the first lens into the lens barrel, even if the force pushing the first lens into the lens barrel is transmitted to the positioning portion, deformation of the lens barrel can be suppressed because the positioning portion overlaps with a part of the second cylindrical portion in the optical axis direction.

[0014] In the present invention, the positioning portion is provided with a notch in a part of the circumferential direction that is cut out radially outward, The through-hole can be provided inside the notch. In this way, when the extended portion extending from the annular portion to the outer circumference is passed through the through-hole, a portion of the extended portion can be accommodated in the notch. Therefore, it becomes easier to bend the extended portion toward the image and insert it into the through-hole. If the notch is not provided, the flexible printed circuit board must be bent from the boundary between the annular portion and the extended portion and inserted into the through-hole, making it difficult to enlarge the annular portion on the inner circumference side of the positioning portion. In contrast, if the notch is provided, after extending the extended portion toward the outer circumference, the portion accommodated in the notch can be bent and inserted into the through-hole. Therefore, the annular portion can be enlarged on the inner circumference side of the positioning portion. Thus, it becomes easier to enlarge the heater portion. [Effects of the Invention]

[0015] According to the present invention, the heater portion of the flexible printed circuit board contacts the image-side flange surface of the first lens. Therefore, the temperature of the image-side of the first lens can be increased by energizing the heater portion. Thus, condensation in the space between the first lens and the second lens, which would otherwise degrade optical performance, can be suppressed. Furthermore, since the elastic member is positioned in a groove facing the first lens from the optical axis direction, the first lens can be easily held in the first barrel. In addition, the extended portion of the flexible printed circuit board passes through a through hole provided on the radially inner side of the positioning portion. Therefore, the positioning portion is interposed between the elastic member and the flexible printed circuit board in the radial direction. Thus, when assembling the first lens with the flexible printed circuit board attached into the lens barrel, the elastic member and the extended portion of the flexible printed circuit board do not interfere with each other. Therefore, it becomes easy to assemble the first lens into the first barrel of the lens barrel. [Brief explanation of the drawing]

[0016] [Figure 1] This is a cross-sectional view of a lens unit to which the present invention is applied. [Figure 2] This is an exploded perspective view of the lens unit. [Figure 3]It is a perspective view of the lens barrel seen from the object side. [Figure 4] It is a perspective view of the lens barrel seen from the image side. [Figure 5] It is a partial enlarged view of the through-hole. [Figure 6] It is a partial cross-sectional view of the lens barrel. [Figure 7] It is a perspective view of the flexible printed circuit board. [Figure 8] It is a diagram for explaining the relationship between the flexible printed circuit board and the lens barrel.

Embodiments for Carrying out the Invention

[0017] Hereinafter, embodiments of a lens unit to which the present invention is applied will be described with reference to the drawings.

[0018] (Configuration of the lens unit) FIG. 1 is a cross-sectional view of a lens unit to which the present invention is applied. FIG. 2 is an exploded perspective view of the lens unit. The lens unit 1 of this embodiment is used in an optical device such as an imaging device. The lens unit 1 has a substantially similar configuration throughout around the optical axis L. The lens unit 1 shown in FIG. 1 includes a wide-angle lens 10 in which a plurality of lenses are arranged in the direction of the optical axis L along the optical axis L, a lens barrel 20 that holds the wide-angle lens 10 inside, and a flexible printed circuit board 30 having a heater portion 35 made of a conductor layer. An imaging element is provided on the image side Lb of the lens barrel 20. The imaging element is a CMOS or the like.

[0019] (Wide-angle lens) As shown in Figures 1 and 2, the wide-angle lens 10 has, for example, a lens configuration of 5 groups and 6 elements. In this embodiment, the wide-angle lens 10 comprises a first lens 11 positioned closest to the object (La), a second lens 12 positioned on the image side (Lb) of the first lens 11, and a plurality of lenses positioned on the image side (Lb) of the second lens 12. More specifically, the wide-angle lens 10 has, from the object side (La) toward the image side (Lb), a first lens 11 with negative power, a second lens 12 with negative power, a third lens 13 with positive power, a fourth lens 14 with positive power, and a cemented lens 18 (fifth lens 15 and sixth lens 16) with positive power. The plurality of lenses are composed of the third lens 13 to the cemented lens 18.

[0020] The first lens 11 is a glass lens or a plastic lens. The first lens 11 is a meniscus lens. The first lens 11 has a convex shape projecting toward the object side La on the first lens surface 111 (object-side lens surface) on the object side La, and a concave shape recessed toward the object side La on the second lens surface 112 (image-side lens surface) on the image side Lb. The first lens 11 comprises a first lens portion 113 and a first flange portion 114 surrounding the first lens portion 113. The first lens surface 111 and the second lens surface 112 constitute the first lens portion 113. The flange surface 115 (image-side flange surface) of the first flange portion 114 facing the image side Lb is located radially outward from the second lens surface 112. The flange surface 115 is coated with black ink for light shielding.

[0021] The second lens 12 is a plastic lens. The second lens 12 has a convex shape that protrudes toward the object-side La surface and a concave shape that is recessed toward the object-side La surface on the image-side Lb surface. The third lens 13 is a plastic lens. The third lens 13 has a convex shape that protrudes toward the object-side La surface on the object-side La surface and a concave shape that is recessed toward the object-side La surface on the image-side Lb surface.

[0022] The fourth lens 14 is a glass lens. The fourth lens 14 is fixed to a frame-shaped holder 5 and positioned inside the lens barrel 20. The cemented lens 18 is a cemented lens of the fifth lens 15 and the sixth lens 16. The fifth lens 15 is a plastic lens with negative power. The sixth lens 16 is a plastic lens with positive power.

[0023] The lens unit 1 has an annular light-shielding sheet 2 between the second lens 12 and the third lens 13, and an annular aperture 3 between the fourth lens 14 and the fifth lens 15.

[0024] The first lens 11 has a larger outer diameter than the second lens 12, the third lens 13, the fourth lens 14, and the cemented lens 18. The second lens 12, the third lens 13, and the cemented lens 18 have approximately equal outer diameters, and in the cemented lens 18, the fifth lens 15 has a larger outer diameter than the sixth lens 16. The fourth lens 14 has a smaller outer diameter than the second lens 12, etc.

[0025] (Lens barrel) Figure 3 is a perspective view of the lens barrel from the object side. Figure 4 is a perspective view of the lens barrel from the image side. Figure 5 is a magnified view of a through-hole. Figure 6 is a cross-sectional view of a portion of the lens barrel. Figure 5 shows the through-hole viewed from the object side.

[0026] The lens barrel 20 is made of resin. Suitable materials for the lens barrel 20 include crystalline plastics with excellent weather resistance (polyethylene, polyamide, polytetrafluoroethylene) and amorphous plastics with relatively low moisture absorption (polycarbonate, etc.). The lens barrel 20 is cylindrical. As shown in Figures 1 to 6, the lens barrel 20 comprises a first cylindrical portion 21 that holds the first lens 11, a second cylindrical portion 22 that holds the second lens 12 and multiple lenses, and an outer diameter cylindrical portion 23 extending from the image side Lb of the first cylindrical portion 21. An annular recess 29 for material removal is formed between the outer diameter cylindrical portion 23 and the second cylindrical portion 22.

[0027] Furthermore, the lens barrel 20 includes an annular connecting portion 24 that connects the first barrel portion 21 and the second barrel portion 22 in the radial direction, and a positioning step portion 25 that protrudes radially inward from the inner circumferential surface of the second barrel portion 22.

[0028] The first cylindrical portion 21 is cylindrical in shape and surrounds the outer surface of the first lens 11. A crimping portion 211 for fixing the first lens 11 is provided at the object-side end La of the first cylindrical portion 21. The inner diameter of the first cylindrical portion 21 is slightly larger than the outer diameter of the first lens 11.

[0029] The connecting portion 24 connects the image-side Lb end of the first cylindrical portion 21 to the object-side La end of the second cylindrical portion 22. The connecting portion 24 includes an annular positioning portion 26 protruding from the object-side La, an annular groove portion 27 recessed into the image-side Lb on the radially outer side of the positioning portion 26, and a through hole 28 that penetrates a portion of the circumferential direction of the connecting portion 24 in the optical axis L direction on the radially inner side of the positioning portion 26.

[0030] The positioning portion 26 contacts the flange surface 115 of the first lens 11 to position the first lens 11 in the optical axis L direction. The positioning portion 26 has a notch 26a on a part of its circumferential direction that is cut out radially outward. An annular elastic member 40 is placed in the groove 27 to seal the space between the first lens 11 and the connecting portion 24. In this example, the elastic member 40 is an O-ring 41. The O-ring 41 is compressed in the optical axis L direction between the flange surface 115 and the bottom of the groove 27.

[0031] The through-hole 28 is located inside the notch 26a. As shown in Figure 5, in this example, when viewed in the optical axis L direction, the through-hole 28 is located inside the notch 26a and outside the virtual circle C formed on the inner circumferential surface of the positioning portion 26. The through-hole 28 communicates with the gap between the second cylindrical portion 22 and the outer diameter cylindrical portion 23. As will be described later, the flexible printed circuit board 30 is inserted into the through-hole 28 and pulled out to the image side Lb of the lens barrel 20 through the gap between the inner circumferential surface of the outer diameter cylindrical portion 23 and the outer circumferential surface of the second cylindrical portion 22. Note that the through-hole 28 does not need to be located outside the virtual circle C formed on the inner circumferential surface of the positioning portion 26, as long as it is located inside the notch 26a.

[0032] The opening edge of the through hole 28 comprises a first opening edge portion 281a extending linearly in the circumferential direction, and a second opening edge portion 281b extending parallel to the first opening edge portion 281a on the outer circumference side of the first opening edge portion 281a. The opening edge of the through hole 28 also comprises a third opening edge portion 282a connecting one circumferential end of the first opening edge portion 281a to one circumferential end of the second opening edge portion 281b, and a fourth opening edge portion 282b connecting the other circumferential end of the first opening edge portion 281a to the other circumferential end of the second opening edge portion 281b. In this example, the third opening edge portion 282a and the fourth opening edge portion 282b are arc-shaped.

[0033] Furthermore, as shown in Figures 1, 4, and 6, the connecting portion 24 has a recess 280 on the image side surface 241 facing the image side Lb, which is recessed toward the object side La so as to surround the through hole 28. The through hole 28 opens into the recess 280. As shown in Figure 1, the recess 280 contains the connecting portion 24 and the flexible A sealing member 60 is provided to fix the printed circuit board 30 and to close the through hole 28. In this example, the sealing member 60 is an adhesive 61 such as a thermosetting resin.

[0034] As shown in Figures 1 and 2, the second cylindrical portion 22 is cylindrical in shape. The outer diameter of the second cylindrical portion 22 is smaller than the outer diameter of the first cylindrical portion 21. Here, as shown in Figure 1, the positioning portion 26 overlaps with a part of the second cylindrical portion 22 when viewed from the optical axis L direction.

[0035] As shown in Figure 4, the outer circumferential surface of the second cylindrical portion 22 includes a flat planar portion 22a that extends from the first opening edge portion 281a to the image side Lb.

[0036] As shown in Figure 1, the inner diameter of the second cylindrical portion 22 decreases slightly toward the image side Lb. As shown in Figure 3, multiple ribs 221 are provided circumferentially on the inner surface of the second cylindrical portion 22. The ribs 221 protrude radially inward and extend in the direction of the optical axis L. When the second lens 12 to the cemented lens 18 are press-fitted into the second cylindrical portion 22, the ribs 221 contact each lens from the outer circumference, positioning each lens radially. As shown in Figure 6, one of the ribs 221 is positioned to overlap with the planar portion 22a when viewed from a direction perpendicular to the optical axis L.

[0037] As shown in Figure 6, an annular crimping portion 222 is provided at the object-side end La of the second cylindrical portion 22. The crimping portion 222 comprises an annular portion 225 having a tapered surface portion 224 that slopes inward toward the object-side La on its radially outward outer surface, and a bent portion 223 that bends radially inward from the object-side La end of the annular portion 225 and contacts the outer edge of the second lens 12 from the object-side La. A space S is provided between the radial positioning portion 26 and the tapered surface portion 224. The image-side end Lb 224a of the tapered surface portion 224 is located closer to the image than the object-side La end 221a of the rib 221.

[0038] As shown in Figures 1 and 2, the positioning step 25 contacts the cemented lens 18, which is positioned closest to the image, from the image-side Lb. The positioning step 25 has an overhang 251 that extends radially inward at the end of the image-side Lb.

[0039] (Flexible printed circuit board) Figure 7 is a perspective view of the flexible printed circuit board 30. Figure 8 is a diagram illustrating the relationship between the flexible printed circuit board 30 and the lens barrel 20. Note that Figure 8 shows the flexible printed circuit board 30 and the lens barrel 20 viewed from the object side.

[0040] As shown in Figures 1 and 2, the flexible printed circuit board 30 is positioned between the first lens 11 and the second lens 12. As shown in Figure 7, the flexible printed circuit board 30 is equipped with a heater section 35 and power supply wiring 36 that is electrically connected to the heater section 35 to supply power to the heater section 35.

[0041] As shown in Figures 2 and 7, the flexible printed circuit board 30 comprises an annular portion 31 that overlaps the flange surface 115 and an extended portion 32 that extends outward from the annular portion 31. An opening 33 is formed in the center of the annular portion 31 so that the lens surface of the second lens 12 is exposed. As shown in Figures 2 and 8, the outer diameter of the annular portion 31 is slightly smaller than the inner diameter of the positioning portion 26. The annular portion 31 abuts against the flange surface 115 radially inward of the positioning portion 26. In this example, the annular portion 31 is attached to the flange surface 115 with adhesive.

[0042] As shown in Figures 1, 2, and 8, the extended portion 32 is bent at a right angle to the annular portion 31 and inserted into the through hole 28. At this time, the bent portion 32a, which is part of the extended portion 32, The extension portion 32, inserted into the through hole 28, is pulled out to the image side Lb of the lens barrel 20 through the gap between the inner circumferential surface of the outer diameter cylinder portion 23 and the outer circumferential surface of the second cylinder portion 22. The through hole 28 and the extension portion 32 are fixed together by adhesive 61 provided in the recess 280.

[0043] As shown in Figure 7, the heater section 35 consists of a heater wire formed in an annular shape on the surface of the flexible printed circuit board 30. The heater wire is located in the annular section 31. The power supply wiring 36 is located in the extended section 32.

[0044] The flexible printed circuit board 30 is made of a resin film such as polyimide. A heater section 35 and power supply wiring 36 are formed on the flexible printed circuit board 30 by a conductive layer such as copper foil.

[0045] The flexible printed circuit board 30 is electrically connected to the board, and when power is supplied from the board to the power supply wiring 36, the heater unit 35 generates heat. When the heater unit 35 generates heat, the first lens 11, which is in contact with the annular portion 31, is heated. Therefore, when using the lens unit 1 at low ambient temperatures, the heater unit 35 heats the first lens 11, which suppresses condensation on the second lens surface 112 of the first lens 11.

[0046] (Effects and Benefits) In this example of the lens unit, the heater portion 35 of the flexible printed circuit board 30 contacts the flange surface 115 of the first lens 11. Therefore, the temperature of the image-side Lb of the first lens 11 can be increased by energizing the heater portion 35. Thus, condensation in the space between the first lens 11 and the second lens 12, which would otherwise degrade optical performance, can be suppressed. Furthermore, the O-ring 41 is positioned in the groove portion 27 facing the first lens 11 from the optical axis L direction. Therefore, compared to the case where the O-ring 41 is positioned radially between the first lens 11 and the first cylindrical portion 21, the first lens 11 is easier to hold in place by the first cylindrical portion 21. In addition, the extended portion 32 of the flexible printed circuit board 30 passes through the through hole 28 provided on the radially inner side of the positioning portion 26. Therefore, the positioning portion 26 is interposed between the O-ring 41 and the flexible printed circuit board 30 in the radial direction. Therefore, when assembling the first lens 11 with the flexible printed circuit board 30 attached into the lens barrel 20, the O-ring 41 and the extended portion 32 of the flexible printed circuit board 30 do not interfere with each other. Consequently, it becomes easy to assemble the first lens 11 into the first cylindrical portion 21 of the lens barrel 20.

[0047] In this example, the connection portion 24 has a recess 280 on the image side surface 241 that is recessed towards the object side La. A through hole 28 opens in the recess 280. The extended portion 32 is fixed to the connection portion 24 by adhesive 61 filled in the recess 280. Thus, the extended portion 32 of the flexible printed circuit board 30 that passes through the through hole 28 of the connection portion 24 can be fixed to the connection portion 24.

[0048] In this example, the opening edge of the through hole 28 in the connecting portion 24 includes a first opening edge portion 281a extending linearly in the circumferential direction, a second opening edge portion 281b extending parallel to the first opening edge portion 281a on the outer circumference side of the first opening edge portion 281a, a third opening edge portion 282a connecting one circumferential end of the first opening edge portion 281a to one circumferential end of the second opening edge portion 281b, and a fourth opening edge portion 282b connecting the other circumferential end of the first opening edge portion 281a to the other circumferential end of the second opening edge portion 281b. The outer circumferential surface of the second cylindrical portion 22 includes a planar portion 22a extending from the first opening edge portion 281a toward the image in the direction of the optical axis L. Therefore, the extension portion 32, which is drawn out from the object side La to the image side Lb of the connecting portion 24 through the through hole 28, can be routed along the planar portion 22a.

[0049] In this example, the inner circumferential surface of the second cylindrical portion 22 is provided with a plurality of ribs 221 extending in the direction of the optical axis L. Multiple ribs 221 contact the second lens 12 from the outer circumference to position the second lens 12 radially. One of the multiple ribs 221A is positioned so as to overlap with the planar portion 22a when viewed from a direction perpendicular to the optical axis L. Therefore, the thickness of the portion of the second cylindrical portion 22 where the planar portion 22a is provided can be increased. This reduces the difference in thickness between the portion of the second cylindrical portion 22 where the planar portion 22a is provided and the portion where it is not, thereby suppressing the occurrence of molding defects in the second cylindrical portion 22 when molding the resin lens barrel 20.

[0050] In this example, an annular crimping portion 222 is provided at the object-side end La of the second cylindrical portion 22. The crimping portion 222 comprises an annular portion 225 having a tapered surface portion 224 that slopes inward toward the object-side La on its radially outward outer surface, and a bent portion 223 that bends radially inward from the object-side La end of the annular portion 225 and contacts the outer edge of the second lens 12 from the object-side La. A space S is provided between the radial positioning portion 26 and the tapered surface portion 224. The image-side Lb end 224a of the tapered surface portion 224 is located on the image-side Lb than the object-side La end 221a of the rib 221. Therefore, when holding the second lens 12 in the second cylindrical portion 22, a jig can be inserted into the space S provided radially outside the annular portion 225 to perform crimping, and the portion of the annular portion 225 located on the object-side La can be bent inward to form a contact portion. Furthermore, since the image-side end 224a of the tapered surface portion 224 overlaps with the object-side end 221a of the rib 221 in a direction perpendicular to the optical axis L, even if the tapered surface portion 224 is provided on the annular portion 225, it is possible to suppress the thinning of the annular portion 225. Therefore, when forming the lens barrel 20, it is possible to suppress the occurrence of molding defects in the crimped portion 222.

[0051] In this example, the positioning portion 26 is provided with a notch 26a cut out radially outward in a portion of its circumferential direction. The through hole 28 is provided inside the notch 26a. Therefore, when passing the extended portion 32, which extends from the annular portion 31 outward, through the through hole 28, the bent portion 32a, which is part of the extended portion 32, can be accommodated in the notch 26a. Thus, it becomes easy to bend the extended portion 32 toward the image side Lb and insert it into the through hole 28. Furthermore, if the notch 26a is not provided, the flexible printed circuit board 30 must be bent from the boundary between the annular portion 31 and the extended portion 32 and inserted into the through hole 28, making it difficult to enlarge the annular portion 31 on the inner circumference side of the positioning portion 26. In contrast, if the notch 26a is provided, the extended portion 32 can be extended outward, and then the portion accommodated in the notch 26a can be bent and inserted into the through hole 28. Therefore, the annular portion 31 can be enlarged on the inner circumference side of the positioning portion 26. Thus, it becomes easier to enlarge the heater portion 35. [Explanation of Symbols]

[0052] 1...Lens unit, 2...Light-shielding sheet, 5...Holder, 10...Wide-angle lens, 11...First lens, 12...Second lens, 13...Third lens, 14...Fourth lens, 15...Fifth lens, 16...Sixth lens, 18...Bonded lens, 20...Lens barrel, 21...First barrel section, 22...Second barrel section, 22a...Flat section, 23...Outer diameter barrel section, 24...Connecting section, 25...Positioning step section, 26...Positioning section, 26a...Notch section, 27...Groove section, 28...Through hole, 29...Recess, 30...Flexible printed circuit board, 31...Annular section, 32...Extended section, 32a...Bent section, 33...Opening hole, 35... Heater section, 36...Power supply wiring, 40...Elastic member, 41...O-ring, 60...Sealing member, 61...Adhesive, 111...First lens surface, 112...Second lens surface, 113...First lens section, 114...First flange section, 115...Flange surface, 211...Crimped section, 221·221A...Rib, 221a...Upper end, 222...Crimped section, 223...Bent section, 224...Inclined surface, 224a...Lower end, 225...Annular section, 241...Image side, 251...Protruding section, 280...Recess, 281·281a...First section, 282...Second section, C...Virtual circle, L...Optical axis, La...Object side, Lb...Image side

Claims

1. The first lens is located closest to the object in the direction of the optical axis, A second lens located on the image side of the first lens, A resin lens barrel comprising a first barrel portion for holding the first lens, a second barrel portion having a smaller outer diameter than the first barrel portion for housing the second lens, and an annular connecting portion connecting the first barrel portion and the second barrel portion in the radial direction, An annular elastic member that seals the space between the first lens and the lens barrel, A flexible printed circuit board comprising an annular portion having an annular heater portion, and an extended portion extending outward from the annular portion, It has, The first lens comprises an object-side lens surface, an image-side lens surface, and an image-side flange surface surrounding the image-side lens surface. The connecting portion comprises an annular positioning portion that abuts against the image-side flange surface to position the first lens in the optical axis direction, an annular groove portion that accommodates the elastic member on the radially outer side of the positioning portion, and a through hole on the radially inner side of the positioning portion that penetrates a portion of the connecting portion in the optical axis direction in the circumferential direction. The annular portion contacts the image-side flange surface on the radially inner side of the positioning portion. The extended portion is pulled out through the through hole towards the image side of the connection portion, The positioning portion includes a notch in a part of the circumferential direction that is cut out radially outward, The through hole is provided inside the notch, A lens unit characterized in that the radially outer surface of the notch is connected to the radially outer opening edge of the through hole.

2. The connecting portion has a recess on the surface facing the image that is recessed toward the object side, The through hole opens in the recess, The lens unit according to claim 1, characterized in that the extended portion is fixed to the connecting portion by a sealing member filled in the recess.

3. The opening edge of the through hole in the connecting portion comprises: a first opening edge portion extending linearly in the circumferential direction; a second opening edge portion extending parallel to the first opening edge portion on the outer circumference side of the first opening edge portion; a third opening edge portion connecting one circumferential end of the first opening edge portion to one circumferential end of the second opening edge portion; and a fourth opening edge portion connecting the other circumferential end of the first opening edge portion to the other circumferential end of the second opening edge portion. The lens unit according to claim 1 or 2, characterized in that the outer circumferential surface of the second cylindrical portion has a planar portion that extends from the first aperture edge portion toward the image in the direction of the optical axis.

4. The inner circumferential surface of the second cylindrical portion is provided with a plurality of ribs extending in the direction of the optical axis, The multiple ribs contact the second lens from the outer circumference to position the second lens radially. The lens unit according to claim 3, characterized in that one of the plurality of ribs is provided at a position that overlaps with the planar portion when viewed from a direction perpendicular to the optical axis.

5. An annular crimping portion is provided at the end portion of the second cylindrical part that is on the object side. The crimping portion comprises an annular portion having a tapered surface portion on its radially outward-facing outer surface that inclins inward toward the object side, and a bent portion that bends radially inward from the object-side end of the annular portion and contacts the outer edge of the second lens from the object side. A space is provided between the positioning portion and the tapered surface portion in the radial direction. The lens unit according to claim 4, characterized in that the image-side end of the tapered surface portion is located closer to the image than the object-side end of the rib.

6. The lens unit according to any one of claims 1 to 5, characterized in that the positioning portion overlaps with a part of the second cylindrical portion when viewed from the direction of the optical axis.

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