Lens group and lens unit

Abstract

The invention provides a lens group which performs good positioning on the position of a first lens relative to a second lens when the first lens is assembled on the second lens. The lens group (8) includes a lens (5) and a lens (6) adjacent to each other with an air gap in the optical axis (L) direction. The lens (5) is provided with an annular flange section (53). The lens (6) is provided with an annular second flange part and a concave part (64) which is arranged on the object side (La) of the second flange part and accommodates the lens (5). The outer peripheral surface 54 of the flange 53 is provided with a first tapered surface 541 inclined radially inward toward the image side Lb. The inner peripheral surface (65) of the recess (64) is provided with a second tapered surface (651) inclined radially outward toward the object side (La). When the lens 5 is housed in the recess 64, the position of the lens 5 with respect to the optical axis L direction of the lens 6 and the position of the center with respect to the optical axis L are positioned by the contact of the first tapered surface 541 and the second tapered surface 651.

Description

Technical Field

[0001] This invention relates to a lens group comprising multiple lenses integrated into one unit, and a lens unit.

[0002] Patent Document 1 describes a lens unit used in an imaging device mounted on a car or surveillance camera. The lens unit of this document includes multiple lenses and a lens barrel holding the multiple lenses. The multiple lenses are arranged sequentially from the object side to the image side as a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens. The fifth lens has a recess that opens towards the object side. The fourth lens is fixed to the recess by fitting into it. Thus, the fourth lens and the fifth lens become a single unit to form a lens group.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2021-39170 Summary of the Invention

[0006] The technical problem that the invention aims to solve

[0007] In the aforementioned lens assembly, the recess has an inner peripheral surface extending linearly along the optical axis, and the fourth lens has an outer peripheral surface extending linearly along the optical axis. During lens assembly, the fourth lens is pressed into the recess using a clamp or similar fixture.

[0008] Here, the inner peripheral surface of the recess and the outer peripheral surface of the fourth lens extend linearly along the optical axis. Therefore, when pressing the fourth lens into the recess, it is sometimes pressed in with the optical axis of the fourth lens tilted. In this case, there is a problem that the optical axes of the fourth lens and the fifth lens are not aligned. Furthermore, even if the fourth lens is positioned against the fifth lens along the optical axis, if the fourth lens is tilted relative to the fifth lens, there is a problem that the air gap between the fourth and fifth lenses is not the designed gap.

[0009] In view of the above problems, the objective of the present invention is to provide a lens group and lens unit in which the position of the first lens relative to the optical axis of the second lens and the position of the center of the optical axis of the first lens relative to the second lens are well positioned when the first lens is assembled onto the second lens.

[0010] Technical solutions for solving technical problems

[0011] To solve the above-mentioned technical problems, the present invention provides a lens assembly, characterized in that it comprises a first lens and a second lens adjacent to each other with an air gap along the optical axis. When the direction of the first lens is designated as a first direction and the direction of the second lens is designated as a second direction along the optical axis, the first lens comprises a first lens surface on the first direction side, a second lens surface on the second direction side, and an annular first flange portion surrounding the first lens surface and the second lens surface. The second lens comprises a third lens surface on the first direction side, a fourth lens surface on the second direction side, an annular second flange portion surrounding the third lens surface and the fourth lens surface, and a recess disposed on the first direction side of the second flange portion and housing the first lens. The outer peripheral surface of the first flange portion comprises a first conical surface inclined radially inward toward the second direction, and the inner peripheral surface of the recess comprises a second conical surface inclined radially outward toward the first direction. When the first lens is housed in the recess, the position of the first lens relative to the second lens along the optical axis and its position relative to the center of the optical axis are positioned through the contact between the first conical surface and the second conical surface.

[0012] According to the present invention, the first conical surface of the first lens and the second conical surface of the second lens are in contact with each other, and the first lens is well positioned relative to the second lens. This allows for the suppression of optical performance degradation of the lens group.

[0013] In this invention, preferably, the second flange portion has a hole that, when the first lens is housed in the recess, connects the space formed between the second lens surface and the third lens surface to the outside. Accordingly, when the first lens is assembled in the recess, air in the space between the first and second lenses can be discharged to the outside of the lens group, thus facilitating the assembly of the first lens in the recess.

[0014] In this invention, it is preferred that the first lens is made of glass. Accordingly, even when the first lens is mounted in the recess, the first lens is not easily deformed, and therefore, the optical performance of the lens group is not easily degraded.

[0015] In this invention, preferably, the second flange portion has an annular planar portion that surrounds the first direction side of the recess on its outer peripheral side and faces the first direction. The outer peripheral surface of the first flange portion has a protruding surface that protrudes towards the first direction side than the planar portion when the first lens is housed in the recess. An adhesive for fixing the first lens and the second lens is provided between the protruding surface and the planar portion. Accordingly, when the adhesive is applied, adhesion of the adhesive to the first lens surface of the first lens can be suppressed.

[0016] In this invention, preferably, the second flange portion has an annular wall portion that surrounds the radially outer side of the planar portion and protrudes in the first direction, the wall portion having a groove cut in the optical axis direction to store the adhesive. Accordingly, the area where the adhesive is applied can be easily controlled.

[0017] In this invention, it is preferable that the second lens is made of resin, and the outer peripheral surface of the second flange has a D-shaped cut surface formed by a plane orthogonal to the radial direction, and the groove is disposed at a position that does not overlap with the D-shaped cut surface in the radial direction. Here, when the D-shaped cut surface that forms the gate mark is provided on the outer peripheral surface, the radial thickness of the wall portion where the D-shaped cut surface is provided is thinner than that of the wall portion other than the wall portion. Therefore, it is possible to provide the groove in the thicker portion of the wall portion accordingly.

[0018] In this invention, preferably, the second flange portion includes a hole portion that, when the first lens is housed in the recess, connects the space formed between the second lens surface and the third lens surface to the outside. Three groove portions are provided, the hole portion is positioned radially overlapping the D-shaped cut surface, one of the three groove portions is positioned opposite the hole portion relative to the optical axis, and the three groove portions are arranged at equal angular intervals around the optical axis. Accordingly, the second lens can be well formed during its fabrication.

[0019] The present invention provides a lens unit, characterized in that it comprises: the lens group; and a lens barrel, the lens barrel holding the lens group, the inner peripheral surface of the lens barrel having a plurality of protrusions disposed in the circumferential direction and contacting the outer peripheral surface of the second flange portion, wherein when the lens group is held in the lens barrel, the protrusions contact the outer peripheral surface of the second flange portion in the circumferential direction at a position in which the portions contacting the first conical surface and the second conical surface do not overlap.

[0020] According to the present invention, when the lens assembly is pressed into the lens barrel, the transmission of stress generated on the outer peripheral surface of the second flange to the portion where the first and second conical surfaces meet can be suppressed. Thus, strain on the first lens can be suppressed.

[0021] The present invention provides a lens unit, characterized in that it comprises: the aforementioned lens group; and a lens barrel, the lens barrel holding the lens group, the lens group comprising a third lens disposed on the second direction side of the second lens and engaged with the second lens, the third lens comprising a fifth lens surface engaged with the fourth lens surface, the inner peripheral surface of the lens barrel comprising a plurality of protrusions disposed in the circumferential direction and contacting the outer peripheral surface of the second flange portion, wherein when the lens group is held in the lens barrel, the protrusions, in the circumferential direction, contact the outer peripheral surface of the second flange portion at a position in which the portions contacting the first conical surface and the second conical surface and the portions engaging with the fourth lens surface and the fifth lens surface do not overlap.

[0022] According to the present invention, when the lens assembly is pressed into the lens barrel, the stress generated on the outer peripheral surface of the second flange can be suppressed from being transmitted to the portion where the first and second conical surfaces meet, and to the portion where the fourth and fifth lens surfaces are joined. This suppresses strain formation on the first lens. Furthermore, it suppresses a decrease in the bonding force at the portion where the fourth and fifth lens surfaces are joined.

[0023] Invention Effects

[0024] According to the present invention, by means of the first conical surface of the first lens and the second conical surface of the second lens being in contact with each other, the position of the first lens relative to the optical axis of the second lens and its position relative to the center of the optical axis are positioned. Thus, the first lens is well positioned relative to the second lens, thereby suppressing the degradation of the optical performance of the lens group. Attached Figure Description

[0025] [ Figure 1 [This is a cross-sectional view of the lens unit to which the present invention is applied.]

[0026] [ Figure 2 [ ] is an exploded three-dimensional view of the lens unit.

[0027] [ Figure 3 [This is a three-dimensional diagram of the lens group.]

[0028] [ Figure 4 [ ] is an exploded stereoscopic view of the lens group.

[0029] [ Figure 5 ]yes Figure 3 A-A sectional view.

[0030] [ Figure 6 [ ] is a perspective view of the cross-sectional view of the cylinder.

[0031] [ Figure 7 [ ] is a diagram showing the relationship between the lens group and the tube. Detailed Implementation

[0032] Embodiments of the present invention will be described with reference to the accompanying drawings. Furthermore, in the following description, the direction along the optical axis L, extending from the optical axis L, will be labeled La on the object side and Lb on the image side.

[0033] (Structure of the lens unit)

[0034] Figure 1 This is a cross-sectional view of the lens unit that incorporates the present invention. Figure 2 This is an exploded perspective view of the lens unit. The lens unit 1 of this method is used in a shooting device mounted on a car or a surveillance camera.

[0035] like Figure 1 and Figure 2 As shown, the lens unit 1 includes a wide-angle lens 10 with multiple lenses arranged along the optical axis L and a lens barrel 9 that holds the wide-angle lens 10 inside. An imaging element is provided on the image side Lb of the lens barrel 9. The imaging element is a CMOS sensor or the like.

[0036] The wide-angle lens 10 comprises, sequentially from the object side La to the image side Lb along the optical axis L, a lens 2, a lens 3, a lens 4, and a lens group 8. The lens group 8 comprises a lens 5 (first lens) and a lens 6 (second lens) that are adjacent to each other and form an air gap along the optical axis L. In addition, the lens group 8 comprises a lens 7 that is joined with the lens 6.

[0037] The lens unit 1 includes an annular light-shielding plate 11 disposed between lens 3 and lens 4, and an annular aperture 12 disposed between lens 4 and lens 5.

[0038] (Wide-angle lens)

[0039] Figure 3 This is a three-dimensional diagram of the lens group. Figure 4 This is an exploded stereoscopic view of the lens group. Figure 5 yes Figure 3 A-A sectional view.

[0040] like Figure 1 As shown, lens 2 is made of resin or glass. Lens 2 is a meniscus lens. Lens 2 has a lens surface 21 on the object side La, a lens surface 22 on the image side Lb, and an annular flange 23 surrounding the lens surface 21 and the lens surface 22 on the outer periphery. Lens surface 21 has a convex shape that protrudes towards the object side La. Lens surface 22 has a concave shape that is recessed towards the object side La.

[0041] like Figure 1As shown, lens 3 is made of resin. Lens 3 is a meniscus lens. Lens 3 has a lens surface 31 on the object side La, a lens surface 32 on the image side Lb, and an annular flange portion 33 surrounding the lens surface 31 and the lens surface 32 on the outer periphery. Lens surface 31 has a convex shape that protrudes towards the object side La. Lens surface 32 has a concave shape that is recessed towards the object side La.

[0042] like Figure 1 As shown, lens 4 is made of resin. Lens 4 has a lens surface 41 on the object side La, a lens surface 42 on the image side Lb, and an annular flange portion 43 surrounding the lens surface 41 and the lens surface 42 on the outer periphery. Lens surface 41 has a convex shape protruding towards the object side La. Lens surface 42 has a convex shape protruding towards the object side La.

[0043] like Figures 3-5 As shown, lens 5 is made of glass. Lens 5 has a lens surface 51 (first lens surface) on the object side La, a lens surface 52 (second lens surface) on the image side Lb, and an annular flange portion 53 (first flange portion) surrounding the lens surface 51 and the lens surface 52 on its outer periphery. Lens surface 51 has a convex shape protruding towards the object side La. Lens surface 52 has a convex shape protruding towards the object side La. The outer peripheral surface 54 of the flange portion 53 has, from the image side Lb toward the object side La, a first conical surface 541 that is radially inwardly inclined toward the image side Lb and a straight surface 542 that extends linearly along the optical axis L.

[0044] like Figures 3-5 As shown, the lens 6 includes a lens surface 61 (third lens surface) on the object side La, a lens surface 62 (fourth lens surface) on the image side Lb, an annular flange portion 63 (second flange portion) surrounding the lens surface 61 and lens surface 62 on the outer periphery, a recess 64 disposed on the object side La of the flange portion 63 and housing the lens 6, and a hole portion 69. The inner peripheral surface 65 of the recess 64 is annular. The inner peripheral surface 65 of the recess 64 has a second conical surface 651 that is radially outward in a first direction. The second conical surface 651 is opposite to the first conical surface 541 in the optical axis L direction. In this embodiment, the first conical surface 541 and the second conical surface 651 have the same inclination angle. Figure 3 and Figure 4 As shown, the outer peripheral surface 631 of the lens 6 has a D-shaped cut surface 661 formed by a plane orthogonal to the radial direction. A gate mark G is formed on the D-shaped cut surface 661.

[0045] The flange portion 63 has an annular planar portion 66 that surrounds the object-side La end of the recess 64 on its outer periphery and faces towards the object-side La, and an annular wall portion 67 that surrounds the radially outer side of the planar portion 66 and protrudes towards the object-side La. The wall portion 67 has a groove portion 68 that is cut in the optical axis L direction to store adhesive B. In this embodiment, three groove portions 68 are provided. The groove portion 68 also functions as a guide for the injection port of an syringe for applying adhesive B. Adhesive B fixes the lens 5 and the lens 6. When the lens 5 is housed in the recess 64, the hole portion 69 communicates with the outside through the space S formed between the lens surface 52 of the lens 5 and the lens surface 61 of the lens 6. In this embodiment, the hole portion 69 is a groove portion 691 formed by cutting the inner peripheral surface 65 of the recess 64 along the optical axis L direction.

[0046] Here, as Figure 3 As shown, the groove 68 is positioned where it does not overlap with the D-shaped cut surface 661 in the radial direction. The hole 69 is positioned where it overlaps with the D-shaped cut surface 661 in the radial direction. One of the three grooves 68, groove 68a, is positioned opposite to the hole 69 relative to the optical axis L. The three grooves 68 are arranged at equal angular intervals with the optical axis L as the center.

[0047] like Figures 3-5 As shown, lens 7 has a lens surface 71 (fifth lens surface) on the object side La, a lens surface 72 on the image side Lb, and an annular flange 73 surrounding the lens surface 71 and the lens surface 72 on the outer periphery. The lens surface 62 of lens 6 and the lens surface 71 of lens 7 are joined by an adhesive. Thus, lens 6 and lens 7 form a joined lens 60.

[0048] Regarding lens group 8, lens 5 and lens 6 become a single unit through fitting lens 5 into recess 64. For example... Figure 5 As shown, when lens 5 is housed in recess 64, it is connected to second conical surface 651 via first conical surface 541, and the position of lens 5 relative to the optical axis L of lens 6 and its center relative to the optical axis L are positioned. As a result, the centers of lens 5 and lens 6 are aligned, and the air gap between lens 5 and lens 6 becomes a predetermined value.

[0049] Here, as Figure 3 and Figure 5 As shown, the outer peripheral surface 54 of the flange portion 53 has a protruding surface 540, which protrudes towards the object side La of the planar portion 66 when the lens 5 is housed in the recess 64. In this embodiment, the protruding surface 540 is composed of a straight surface 542 and a portion of the first conical surface 541. An adhesive B for fixing the lens 5 and the lens 6 is provided between the protruding surface 540 and the planar portion 66.

[0050] (Mirror tube)

[0051] Figure 6This is a perspective view of the cross-section of the lens barrel. The lens barrel 9 is made of resin. The materials used for the lens barrel 9 include crystalline plastics with excellent weather resistance (polyethylene, polyamide, polytetrafluoroethylene) and amorphous plastics with low moisture absorption (polycarbonate, etc.). Figure 1 and Figure 6 As shown, the lens barrel 9 includes a first barrel portion 91 for holding the lens 2, a second barrel portion 92 for holding the lenses 3 to 7, an abutting portion 93 connecting the first barrel portion 91 and the second barrel portion 92, and a stepped portion 94 extending radially inward from the inner circumference of the second barrel portion 92.

[0052] The first cylindrical portion 91 is cylindrical and surrounds the outer peripheral surface of the lens 2. A riveting portion 911 for fixing the lens 2 is provided at the object side La end of the first cylindrical portion 91. The inner diameter of the first cylindrical portion 91 is slightly larger than the outer diameter of the lens 2.

[0053] The contact surface 93 is an annular surface facing the object side La. The contact surface 93 is in contact with the flange surface 231 of the flange portion 23 from the image side Lb. The contact surface 93 has an annular groove 931 recessed towards the image side Lb. An elastic member 13 is disposed in the groove 931. In this embodiment, the elastic member 13 is an O-ring.

[0054] The second cylindrical portion 92 is cylindrical in shape. The inner diameter of the second cylindrical portion 92 slightly decreases towards the image side Lb. The second cylindrical portion 92 has a first protrusion 921, a second protrusion 922, and a third protrusion 923 sequentially arranged from the object side La towards the image side Lb. The first protrusion 921, the second protrusion 922, and the third protrusion 923 are provided in multiples in the circumferential direction, and the number of each is the same. A riveting portion 924 for fixing the lens 3 is provided at the object side La end of the second cylindrical portion 92.

[0055] The first protrusion 921 protrudes radially inward and extends along the optical axis L. The first protrusion 921 positions the lens 3 radially when it is pressed into the second cylindrical portion 92. The second protrusion 922 protrudes radially inward and extends along the optical axis L. The second protrusion 922 positions the lens 4 radially when it is pressed into the second cylindrical portion 92. The third protrusion 923 protrudes radially inward and extends along the optical axis L. The third protrusion 923 positions the lens group 8 radially when it is pressed into the second cylindrical portion 92.

[0056] The step portion 94 connects to the flange portion 63 of the lens 6 from the image side Lb, and positions the lens group 8 along the optical axis L.

[0057] (Fixing of the wide-angle lens)

[0058] Lens 3, lens 4, and lens group 8 are sequentially pressed into the second cylindrical portion 92, starting from lens group 8 on the image side Lb. The flange portion 63 of lens 6 connects to the stepped portion 94 from the object side La. The flange portion 43 of lens 4 connects to the flange portion 63 of lens 6 from the object side La via aperture 12. The flange portion 33 of lens 3 connects to the flange portion 43 of lens 4 from the object side La via light-blocking plate 11.

[0059] The flange portion 33 of the lens 3 is covered from the object side La by the riveting portion 924, thereby restricting the movement of the lens 3 toward the object side La. As a result, the lens 3, the light shield 11, the lens 4, the aperture 12, and the lens group 8 are held inside the second barrel portion 92.

[0060] Here, Figure 7 This is a diagram showing the relationship between the lens group and the tube. For example... Figure 7 As shown, the outer peripheral surface 631 of lens 6, from the object side La towards the image side Lb, sequentially comprises a first outer peripheral surface 631a extending parallel to the optical axis L and a second outer peripheral surface 631b inclined radially inward towards the image side Lb. When lens group 8 is held in the second barrel portion 92, the third protrusion 923, in the circumferential direction, contacts the first outer peripheral surface 631a of flange portion 63 at a position where the portion E1 that contacts the first conical surface 541 and the second conical surface 651 and the portion E2 that engages the lens surface 62 of lens 6 and the lens surface 71 of lens 7 do not overlap.

[0061] Lens 2 is pressed into the first cylindrical portion 91. More specifically, the flange portion 23 of lens 2 is covered from the object side La by the riveting portion 911, thereby restricting movement towards the object side La. As a result, lens 2 is held inside the first cylindrical portion 91. At this time, the elastic member 13 is in a state of elastic deformation in the optical axis L direction, adhering to the flange surface 231 and the groove portion 931 of lens 2.

[0062] (Effects)

[0063] The lens group 8 of this embodiment includes lenses 5 and 6 adjacent to each other with an air gap in the optical axis L. Lens 5 has a lens surface 51 on the object side La, a lens surface 52 on the image side Lb, and an annular flange portion 53 surrounding the lens surface 51 and lens surface 52. Lens 6 has a lens surface 61 on the object side La, a lens surface 62 on the image side Lb, an annular flange portion 63 surrounding the lens surface 61 and lens surface 62, and a recess 64 provided on the object side La of the flange portion 63 for receiving the lens 5. The outer peripheral surface 54 of the flange portion 53 has a first conical surface 541 that is radially inward toward the image side Lb. The inner peripheral surface 65 of the recess 64 has a second conical surface 651 that is radially outward toward the object side La. When the lens 5 is received in the recess 64, the position of the lens 5 relative to the optical axis L of the lens 6 and its position relative to the center of the optical axis L are positioned by the contact between the first conical surface 541 and the second conical surface 651.

[0064] Thus, by connecting the first conical surface 541 of lens 5 and the second conical surface 651 of lens 6, lens 5 is well positioned relative to lens 6. As a result, the degradation of the optical performance of lens group 8 can be suppressed.

[0065] The flange portion 63 has a hole 69, which connects the space S formed between the lens surface 52 and the lens surface 61 to the outside when the lens 5 is housed in the recess 64. Therefore, when the lens 5 is assembled into the recess 64, the air in the space S between the lens 5 and the lens 6 can be discharged to the outside of the lens group 8, thus making it easy to assemble the lens 5 into the recess 64.

[0066] Lens 5 is made of glass. Therefore, even when lens 5 is fitted into recess 64, lens 5 is not easily deformed, and thus the optical performance of lens group 8 is not easily degraded.

[0067] The flange portion 63 has an annular planar portion 66 that surrounds the object-side La of the recess 64 on its outer peripheral side and faces the object-side La. The outer peripheral surface 54 of the flange portion 53 has a protruding surface 540 that protrudes towards the object-side La of the planar portion 66 when the lens 5 is housed in the recess 64. An adhesive B for fixing the lens 5 and the lens 6 is provided between the protruding surface 540 and the planar surface 66. Thus, when the adhesive B is applied, it is possible to prevent the adhesive B from adhering to the lens surface 51 of the object-side La of the lens 5.

[0068] The flange portion 63 has an annular wall portion 67 that surrounds the radially outer side of the planar portion 66 and protrudes toward the object side La. The wall portion 67 has a groove portion 68 that is cut in the optical axis L direction to store the adhesive B. As a result, the area where the adhesive B is applied can be easily controlled.

[0069] Lens 6 is made of resin. The outer peripheral surface 631 of flange 63 has a D-shaped cut surface 661 formed by a plane orthogonal to the radial direction. Groove 68 is disposed at a position that does not overlap with D-shaped cut surface 661 in the radial direction. Here, when D-shaped cut surface 661 forming gate mark G is provided on outer peripheral surface 631, the radial thickness of wall 67 is thinner in the portion where D-shaped cut surface 661 is provided compared to the wall 67 of other portions. Therefore, groove 68 can be provided in the thicker portion of wall 67 accordingly.

[0070] Three grooves 68 are provided. A hole 69 is positioned to overlap radially with the D-shaped cut surface 661. One of the three grooves 68, groove 68a, is positioned opposite the hole 69 relative to the optical axis L. The three grooves 68 are arranged at equal angular intervals centered on the optical axis L. Therefore, during the forming of the lens 6, shrinkage or other defects are less likely to occur on the lens 6, thus enabling the lens 6 to be formed well.

[0071] The lens unit 1 of this embodiment includes a lens group 8 and a lens barrel 9 for holding the lens group 8. The lens group 8 includes a lens 7 disposed on the image side Lb of the lens 6 and joined to the lens 6. The lens 7 includes a lens surface 71 joined to a lens surface 62. The inner peripheral surface of the lens barrel 9 includes a plurality of third protrusions 923 provided in the circumferential direction and in contact with the outer peripheral surface 631 of the flange portion 63. When the lens group 8 is held in the lens barrel 9, the third protrusions 923 are in contact with the outer peripheral surface 631 of the flange portion 63 in the circumferential direction at a position where the portion E1 in contact with the first conical surface 541 and the second conical surface 651 and the portion E2 in contact with the lens surface 62 and the lens surface 71 do not overlap. Therefore, when the lens group 8 is pressed into the lens barrel 9, the stress generated on the outer peripheral surface 631 of the flange portion 63 can be suppressed from being transmitted to the portion E1 in contact with the first conical surface 541 and the second conical surface 651 and the portion E2 in contact with the lens surface 62 and the lens surface 71. As a result, strain on lens 5 can be suppressed. In addition, the reduction in the bonding force of the joint E2 between lens surface 62 and lens surface 71 can be suppressed.

[0072] (Other implementation methods)

[0073] The lens group can also be configured such that the lens corresponding to the first lens of the present invention is located on the image side Lb, and the lens corresponding to the second lens of the present invention is located on the object side La.

[0074] In the above configuration, lens group 8 includes a joining lens 60, but lens group 8 may also be without a joining lens 60. That is, lens group 8 may also consist only of lens 5 and lens 6.

[0075] Lens group 8 may also have a lens on the image side Lb of lens 7 that is joined with lens 7. That is, lens group 8 may also have a joined lens composed of three lenses.

[0076] The hole 69 is not limited to the above-described manner. The hole 69 can be any shape as long as it is a shape that connects the space S to the outside.

[0077] The protruding surface 540 is not limited to the above-described manner. The protruding surface 540 is part of the outer peripheral surface 54, and can be any shape as long as the shape of the adhesive B is provided.

[0078] Furthermore, this technology can adopt the following structure. (1)

[0080] A lens assembly, characterized in that,

[0081] It comprises a first lens and a second lens that are adjacent to each other and have an air gap along the optical axis.

[0082] In the optical axis direction, if the direction where the first lens is located is defined as the first direction, and the direction where the second lens is located is defined as the second direction, then...

[0083] The first lens has a first lens surface on the first direction side, a second lens surface on the second direction side, and an annular first flange portion surrounding the first lens surface and the second lens surface.

[0084] The second lens includes a third lens surface on the first direction side, a fourth lens surface on the second direction side, an annular second flange portion surrounding the third lens surface and the fourth lens surface, and a recess portion disposed on the first direction side of the second flange portion and for receiving the first lens.

[0085] The outer peripheral surface of the first flange portion has a first conical surface that is radially inwardly inclined toward the second direction.

[0086] The inner peripheral surface of the recess has a second conical surface that is radially outward in the first direction.

[0087] When the first lens is housed in the recess, the position of the first lens relative to the optical axis of the second lens and the position relative to the center of the optical axis are positioned by the first conical surface and the second conical surface being connected. (2)

[0089] According to the lens group described in (1), the characteristic is that,

[0090] The second flange portion has a hole portion, which, when the first lens is housed in the recess, forms a space between the second lens surface and the third lens surface that is connected to the outside. (3)

[0092] According to the lens group described in (1) or (2), the characteristic is that,

[0093] The first lens is made of glass. (4)

[0095] The lens assembly according to any one of (1) to (3) is characterized in that,

[0096] The second flange portion has an annular planar portion that surrounds the first direction side of the recess on its outer peripheral side and faces the first direction.

[0097] The outer peripheral surface of the first flange portion has a protruding surface, which protrudes towards the first direction side compared to the planar portion when the first lens is housed in the recess.

[0098] An adhesive is provided between the protruding surface and the flat portion to fix the first lens and the second lens. (5)

[0100] According to the lens group described in (4), the feature is that,

[0101] The second flange portion has an annular wall portion that surrounds the radially outer side of the planar portion and protrudes in the first direction.

[0102] The wall portion has a groove for storing the adhesive by making a cut in the direction of the optical axis. (6)

[0104] According to the lens group described in (5), the characteristic is that,

[0105] The second lens is made of resin.

[0106] The outer peripheral surface of the second flange portion has a D-shaped cut surface formed by a plane orthogonal to the radial direction.

[0107] The groove is positioned in a radial direction that does not overlap with the D-shaped cut surface. (7)

[0109] According to the lens group described in (6), the characteristic is that,

[0110] The second flange portion has a hole, which, when the first lens is housed in the recess, connects the space between the second lens surface and the third lens surface to the outside.

[0111] The groove section has three sections.

[0112] The hole is positioned to overlap with the D-shaped cut surface in the radial direction.

[0113] One of the three grooves is positioned opposite the hole relative to the optical axis.

[0114] The three grooves are arranged at equal angular intervals with the optical axis as the center. (8)

[0116] A lens unit, characterized in that it comprises:

[0117] The lens group as described in any one of (1) to (7); and

[0118] Lens barrel, which holds the lens group

[0119] The inner circumferential surface of the lens barrel has a plurality of protrusions arranged in the circumferential direction and connected to the outer circumferential surface of the second flange portion.

[0120] When the lens assembly is held in the lens barrel, the protrusion is in contact with the outer peripheral surface of the second flange in the circumferential direction at a position that does not overlap with the portions that contact the first and second conical surfaces. (9)

[0122] A lens unit, characterized in that it comprises:

[0123] The lens group as described in any one of (1) to (7); and

[0124] Lens barrel, which holds the lens group

[0125] The lens group includes a third lens disposed on the second direction side of the second lens and joined with the second lens.

[0126] The third lens has a fifth lens surface that engages with the fourth lens surface.

[0127] The inner circumferential surface of the lens barrel has a plurality of protrusions arranged in the circumferential direction and connected to the outer circumferential surface of the second flange portion.

[0128] When the lens group is held in the lens barrel, the protrusion is in contact with the outer peripheral surface of the second flange in the circumferential direction at a position where the portion that contacts the first conical surface and the second conical surface and the portion that engages with the fourth lens surface and the fifth lens surface do not overlap.

[0129] Explanation of reference numerals in the attached figures

[0130] 1…lens unit; 2-7…lenses; 8…lens group; 9…lens barrel; 10…wide-angle lens; 11…light shield; 12…aperture; 13…elastic component; 21…lens surface; 22…lens surface; 23…flange; 31…lens surface; 32…lens surface; 33…flange; 41…lens surface; 42…lens surface; 43…flange; 51…lens surface; 52…lens surface; 53…flange; 54…outer peripheral surface; 60…joint lens; 61…lens surface; 62…lens surface; 63…flange; 64…recess; 65…inner peripheral surface; 66…flat part; 67…wall part; 68…groove part; 69…hole part ; 71…lens surface; 72…lens surface; 73…flange portion; 91…first cylindrical portion; 92…second cylindrical portion; 93…abutting portion; 94…step portion; 231…flange surface; 540…protruding surface; 541…first conical surface; 542…straight surface; 631…outer peripheral surface; 631a…first outer peripheral surface; 631b…second outer peripheral surface; 651…second conical surface; 661…D-shaped cut surface; 691…groove portion; 911…riveting portion; 921…first protrusion; 922…second protrusion; 923…third protrusion; 924…riveting portion; 931…groove portion; B…adhesive; B…gate mark; L…optical axis.

Claims

1. A lens assembly, characterized in that, It comprises a first lens and a second lens that are adjacent to each other and have an air gap along the optical axis. In the optical axis direction, if the direction where the first lens is located is defined as the first direction, and the direction where the second lens is located is defined as the second direction, then... The first lens has a first lens surface on the first direction side, a second lens surface on the second direction side, and an annular first flange portion surrounding the first lens surface and the second lens surface. The second lens includes a third lens surface on the first direction side, a fourth lens surface on the second direction side, an annular second flange portion surrounding the third lens surface and the fourth lens surface, and a recess portion disposed on the first direction side of the second flange portion and for receiving the first lens. The outer peripheral surface of the first flange portion has a first conical surface that is radially inwardly inclined toward the second direction. The inner peripheral surface of the recess has a second conical surface that is radially outward in the first direction. When the first lens is housed in the recess, the position of the first lens relative to the optical axis of the second lens and the position relative to the center of the optical axis are positioned by the first conical surface and the second conical surface being connected.

2. The lens assembly according to claim 1, characterized in that, The second flange portion has a hole portion, which, when the first lens is housed in the recess, forms a space between the second lens surface and the third lens surface that is connected to the outside.

3. The lens assembly according to claim 1, characterized in that, The first lens is made of glass.

4. The lens assembly according to claim 1, characterized in that, The second flange portion has an annular planar portion that surrounds the first direction side of the recess on its outer peripheral side and faces the first direction. The outer peripheral surface of the first flange portion has a protruding surface, which protrudes towards the first direction side compared to the planar portion when the first lens is housed in the recess. An adhesive is provided between the protruding surface and the flat portion to fix the first lens and the second lens.

5. The lens assembly according to claim 4, characterized in that, The second flange portion has an annular wall portion that surrounds the radially outer side of the planar portion and protrudes in the first direction. The wall portion has a groove for storing the adhesive by making a cut in the direction of the optical axis.

6. The lens assembly according to claim 5, characterized in that, The second lens is made of resin. The outer peripheral surface of the second flange portion has a D-shaped cut surface formed by a plane orthogonal to the radial direction. The groove is positioned in a radial direction that does not overlap with the D-shaped cut surface.

7. The lens assembly according to claim 6, characterized in that, The second flange portion has a hole, which, when the first lens is housed in the recess, connects the space between the second lens surface and the third lens surface to the outside. The groove section has three sections. The hole is positioned to overlap with the D-shaped cut surface in the radial direction. One of the three grooves is positioned opposite the hole relative to the optical axis. The three grooves are arranged at equal angular intervals with the optical axis as the center.

8. A lens unit, characterized in that, have: The lens assembly according to any one of claims 1 to 7; and Lens barrel, which holds the lens group The inner circumferential surface of the lens barrel has a plurality of protrusions arranged in the circumferential direction and connected to the outer circumferential surface of the second flange portion. When the lens assembly is held in the lens barrel, the protrusion is in contact with the outer peripheral surface of the second flange in the circumferential direction at a position that does not overlap with the portions that contact the first and second conical surfaces.

9. A lens unit, characterized in that, have: The lens assembly according to any one of claims 1 to 7; and Lens barrel, which holds the lens group The lens group includes a third lens disposed on the second direction side of the second lens and joined with the second lens. The third lens has a fifth lens surface that engages with the fourth lens surface. The inner circumferential surface of the lens barrel has a plurality of protrusions arranged in the circumferential direction and connected to the outer circumferential surface of the second flange portion. When the lens group is held in the lens barrel, the protrusion is in contact with the outer peripheral surface of the second flange in the circumferential direction at a position where the portion that contacts the first conical surface and the second conical surface and the portion that engages with the fourth lens surface and the fifth lens surface do not overlap.

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