Optical imaging lens

Abstract

This invention discloses an optical imaging lens, comprising an outer cover, a lens barrel, and a plurality of lenses disposed within the lens barrel. The front end of the lens barrel includes an object-side opening, and the rear end includes an image-side opening. The inner diameter of the object-side opening is smaller than the inner diameter of the image-side opening. The outer cover is conical and disposed on the outer surface of the front end of the lens barrel. The outer cover includes an object-side opening and an image-side opening, the maximum outer diameter of which is smaller than the maximum outer diameter of the image-side opening. The length of the outer cover along the optical axis is greater than 40% of the length of the lens barrel along the optical axis.

Description

Technical Field

[0001] This invention relates to an optical element, and more particularly to an optical imaging lens. Background Technology

[0002] The specifications of portable electronic devices are constantly evolving, and the specifications of their key components—optical imaging lenses—must also be continuously improved to meet consumer demands and be used in various fields. Those skilled in the art know that using plastic materials to make lens barrels is not only easy to process but also reduces weight and cost, and therefore is widely used in various optical lenses.

[0003] Chinese utility model patent CN209387961U provides a lens module with a metal insert inside a plastic lens barrel. The supporting part of the metal insert surrounds the outer periphery of the top of the plastic lens barrel, which can protect the plastic lens barrel and improve the structural strength of the top of the lens barrel, giving the top of the lens barrel good pressure resistance. However, from the cross-section, there is a chamfered structure, which concentrates stress. Although it has pressure resistance for the top, it is easy to damage the front part of the lens from impacts in other directions. In addition, it does not provide a solution for reducing stray light and resisting drops.

[0004] Chinese utility model patent CN209525509U addresses the problem of deformation in thinner sections of the lens barrel during high-temperature curing with strong adhesive in threadless lens barrel structures, hindering lens-to-barrel fit. The solution involves attaching a metal sleeve to the outer surface of the lens barrel. After high-temperature curing, the metal sleeve protects the thinner sections of the lens barrel, enhancing its overall strength and reducing deformation, thus improving the lens module's performance. The lens barrel and metal sleeve are integrally molded during injection molding, increasing the lens module's robustness. However, this design also features a chamfered structure, leading to stress concentration. Furthermore, it does not address how to improve the structural strength of the top edge of the lens barrel while simultaneously reducing stray light, nor does it disclose how to maintain the lens's structural strength while reducing its size, preventing damage from external impacts and drops.

[0005] Chinese utility model patent CN208907936U provides a lens module whose lens barrel includes a metal sleeve embedded within the lens barrel, with the lens barrel and metal sleeve integrally formed. The metal sleeve embedded within the lens barrel can greatly improve the lens barrel's resistance to deformation, thus preventing deformation during high-temperature curing with strong adhesives when the lens barrel is assembled into the lens module, thereby improving assembly stability and product yield. However, this type of metal sleeve embedded within the lens barrel is difficult and costly to manufacture, and it also has a chamfered structure, resulting in stress concentration. Furthermore, because the impact-bearing surface is still made of plastic, its impact resistance is limited within the size of miniaturized lenses.

[0006] With the trend towards thinner and smaller portable electronic devices, lens modules are becoming increasingly smaller. As a result, the strength of plastic materials is no longer sufficient for lens barrels to withstand impacts and drops, leaving them unable to protect internal components. Therefore, providing a simple and economical way to improve the structural strength of miniaturized lens modules, preventing external impacts and drops from affecting lens performance, while also reducing stray light, is a current goal. Summary of the Invention

[0007] Therefore, the present invention provides an optical imaging lens that facilitates the sequential arrangement of the outer casing, lens barrel, and multiple lenses for easy assembly, enhances the structural strength of the front end of the lens barrel, reduces the volume of the optical imaging lens, and improves its resistance to drops.

[0008] This invention provides an optical imaging lens, comprising an outer casing, a lens barrel, and a plurality of lenses disposed within the lens barrel along an optical axis from an object side to an image side. The lens barrel includes a front end near the object side and a rear end near the image side. The front end includes an object-side opening, and the rear end includes an image-side opening, the inner diameter of which is smaller than the inner diameter of the image-side opening. The front end of the lens barrel has an annular plane perpendicular to the optical axis and located on a reference plane. The outer casing is conical and disposed on the outer surface of the front end of the lens barrel. The outer casing includes an object-side opening and an image-side opening, the maximum outer diameter of which is smaller than the maximum outer diameter of the image-side opening. The outer casing has an annular plane near the object side and perpendicular to the optical axis, an inner conical surface adjacent to the annular plane, and an outer conical surface. The length of the outer casing along the optical axis is greater than 40% of the length of the lens barrel along the optical axis. The optical imaging lens satisfies the following condition: 0.450≦Tcv / Wbr≦1.400, where Tcv is the thickness of the outer casing on the reference plane, and Wbr is the width of the lens barrel annular plane on the reference plane.

[0009] In one embodiment of the present invention, the optical imaging lens further includes a pressure-sensitive adhesive disposed between the outer cover and the lens barrel.

[0010] In one embodiment of the present invention, the outer cover includes at least one outer cover inlay structure, the lens barrel includes at least one lens barrel inlay structure, and the outer cover is combined with at least one lens barrel inlay structure of the lens barrel by the at least one outer cover inlay structure.

[0011] In one embodiment of the present invention, the number of the at least one outer cover inlay structure and the number of the at least one lens barrel inlay structure are the same, and the at least one lens barrel inlay structure is a protruding structure and is adjacent to the image-side opening of the outer cover.

[0012] This invention provides an optical imaging lens, comprising an outer cover, a lens barrel, and a plurality of lenses disposed within the lens barrel along an optical axis from an object side to an image side. The outer cover is made of a different material than the lens barrel. The lens barrel includes a front end near the object side and a rear end near the image side. The front end includes an object-side opening, and the rear end includes an image-side opening, the inner diameter of which is smaller than the inner diameter of the image-side opening. The front end of the lens barrel has an annular plane perpendicular to the optical axis and located on a reference plane. The outer cover is conical and disposed on the outer surface of the front end of the lens barrel. The outer cover includes an object-side opening and an image-side opening, the maximum outer diameter of which is smaller than the maximum outer diameter of the image-side opening. The outer cover has a cover mating surface, and the lens barrel and the outer cover are bonded together by applying adhesive between the outer surface and the cover mating surface. The cover mating surface has a plurality of annular grooves. The optical imaging lens satisfies the following condition: 2.600≦Tcv / Ds≦6.000, where Tcv is the thickness of the outer cover on the reference plane, and Ds is the maximum depth of the annular groove.

[0013] In one embodiment of the present invention, the minimum distance from the opening on the outer side of the outer cover to the annular groove is between 0.550 and 0.700 mm.

[0014] In one embodiment of the present invention, the optical imaging lens satisfies the following condition: 2.800≦Lc / (n*Ls)≦4.700, where the first direction is from the outer cover object side opening to the outer cover image side opening along the cover mating surface, where Lc is the minimum length of the cover mating surface from the outer cover object side opening to the outer cover image side opening, Ls is the maximum length of each annular groove in the first direction, and n is the number of annular grooves.

[0015] In one embodiment of the present invention, the above-mentioned annular grooves are arranged periodically.

[0016] In one embodiment of the present invention, the optical imaging lens described above satisfies the following condition: 2.300≦Lc / (n*Lps)≦29.000, where Lc is the minimum length of the cover mating surface from the opening on the outer cover side to the opening on the outer cover image side, Lps is the minimum length between any two adjacent parts in the annular groove, and n is the number of annular grooves.

[0017] In one embodiment of the present invention, the optical imaging lens further includes a colloid disposed between the outer cover and the lens barrel.

[0018] In one embodiment of the present invention, the one closest to the object side among the plurality of lenses is the first lens, and the outer cover contacts one object side of the first lens.

[0019] In one embodiment of the present invention, the angle between the outer cover annular plane and the outer cover conical surface is between 100 and 110 degrees.

[0020] In one embodiment of the present invention, the outer cover is made of metal.

[0021] In one embodiment of the present invention, the outer cover may be made of a soft material with a Shore A hardness ranging from 70 to 90.

[0022] In one embodiment of the present invention, the outer cover contacts the annular plane of the lens barrel.

[0023] In one embodiment of the present invention, the optical imaging lens described above satisfies the following condition: 1.120≦Dcv / Dbr≦1.201, where Dcv is the maximum outer diameter of the outer casing on the reference plane, and Dbr is the maximum outer diameter of the lens barrel on the reference plane.

[0024] In one embodiment of the present invention, the optical imaging lens described above satisfies the following condition: 1.000≦Dinmax / Dinmin≦1.400, where Dinmax is the maximum inner diameter of the inner ring conical surface and Dinmax is the minimum inner diameter of the inner ring conical surface.

[0025] In one embodiment of the present invention, the optical imaging lens described above satisfies the following condition: 1.150≦Dcvox / Dcvon≦1.500, where Dcvox is the maximum outer diameter of the housing and Dcvon is the minimum outer diameter of the housing.

[0026] In one embodiment of the present invention, an air gap is provided between the outer surface of the front end of the lens barrel and the outer cover.

[0027] In one embodiment of the present invention, the length of the air gap on the optical axis is 20% to 40% of the length of the outer cover on the optical axis.

[0028] In one embodiment of the present invention, the outer surface of the lens barrel is provided with a plurality of dispensing areas and a plurality of mating areas arranged alternately. The number of dispensing areas is the same as the number of mating areas. Each dispensing area has a receiving groove for receiving glue. The depth of the receiving groove is between 0.005 and 0.100 mm. The mating area is in direct contact with the outer cover.

[0029] In one embodiment of the present invention, the number of the above-mentioned dispensing areas is at least 3 and at most 12.

[0030] In one embodiment of the present invention, the optical imaging lens described above satisfies the following condition: 3.100≦Pbr / Smin≦12.500, where Pbr is the minimum circumference of the object-side opening of the lens barrel, and Smin is the minimum arc length of one of the dispensing areas closest to the object side.

[0031] In one embodiment of the present invention, the optical imaging lens described above satisfies the following condition: 4≦CTEpc / CTEoc≦10, where CTEpc is the thermal expansion coefficient of the lens barrel and CTEoc is the thermal expansion coefficient of the outer casing.

[0032] In one embodiment of the present invention, the optical imaging lens further includes a colloid disposed between the outer cover and the lens barrel, wherein the colloid is solid at temperatures below 90°C and softens when reheated to 50~75°C.

[0033] Based on the above, in the optical imaging lens of the present invention, the optical imaging lens includes an outer cover, a lens barrel, and a plurality of lenses disposed within the lens barrel along an optical axis from an object side to an image side. The front end of the lens barrel includes an object-side opening, and the rear end of the lens barrel includes an image-side opening, with the inner diameter of the object-side opening being smaller than the inner diameter of the image-side opening. Therefore, this arrangement not only facilitates assembly by sequentially arranging the outer cover, lens barrel, and multiple lenses, but also reduces the volume of the optical imaging lens while maintaining the wall thickness of the lens barrel. Furthermore, the outer cover includes an object-side opening and an image-side opening, with the maximum outer diameter of the object-side opening being smaller than the maximum outer diameter of the image-side opening. Therefore, the outer cover enhances the strength of the front end of the lens barrel. Additionally, the length of the outer cover along the optical axis is greater than 40% of the length of the lens barrel along the optical axis. This increases the protective area of ​​the lens barrel and the bonding force between the outer cover and the lens barrel, thereby improving drop resistance. Furthermore, the conical shape of the outer casing not only facilitates machining but also disperses impact force when placed on the outer surface of the lens barrel. Its chamfer-free design reduces stress concentration, effectively preventing damage from external impacts or drops, thus minimizing the possibility of localized deformation and protecting internal components. In addition, the optical imaging lens satisfies the following condition: 0.450≦Tcv / Wbr≦1.400, where Tcv is the thickness of the outer casing on the reference plane, and Wbr is the width of the annular plane of the lens barrel on the reference plane. Therefore, by controlling the ratio of the width of the annular plane of the lens barrel to the thickness of the outer casing, it is beneficial to maintain the miniaturized size of the lens while ensuring the optical imaging lens's resistance to drops. Attached Figure Description

[0034] Figure 1 This is a cross-sectional schematic diagram of the optical imaging lens according to the first embodiment of the present invention.

[0035] Figure 2 This is a cross-sectional schematic diagram of the optical imaging lens according to the second embodiment of the present invention.

[0036] Figure 3 This is a cross-sectional schematic diagram of the optical imaging lens according to the third embodiment of the present invention.

[0037] Figure 4 This is a cross-sectional schematic diagram of the optical imaging lens according to the fourth embodiment of the present invention.

[0038] Figure 5 This is a cross-sectional schematic diagram of the optical imaging lens according to the fifth embodiment of the present invention.

[0039] Figure 6 This is a front view schematic diagram of the optical imaging lens according to the fifth embodiment of the present invention.

[0040] Figure 7 This is a front view schematic diagram of the optical imaging lens according to the sixth embodiment of the present invention.

[0041] Figure 8 This is a front view schematic diagram of the optical imaging lens according to the seventh embodiment of the present invention.

[0042] Figure 9 The numerical values ​​of the important parameters and their relationships of the optical imaging lenses of the first to seventh embodiments of the present invention are shown.

[0043] Figure 10 This is a cross-sectional schematic diagram of the optical imaging lens according to the eighth embodiment of the present invention.

[0044] Figure 11 This is a cross-sectional schematic diagram of the optical imaging lens according to the ninth embodiment of the present invention.

[0045] Figure 12 This is a cross-sectional schematic diagram of the optical imaging lens according to the tenth embodiment of the present invention.

[0046] Figure 13 This is a cross-sectional schematic diagram of the optical imaging lens according to the eleventh embodiment of the present invention.

[0047] Figure 14 The numerical values ​​of the important parameters and their relationships of the optical imaging lenses of the eighth to eleventh embodiments of the present invention are shown.

[0048] Explanation of reference numerals in the attached figures: 99: Imaging plane; 100, 100A~100F: Optical imaging lens; 110, 110A~110D: outer casing; 120, 120A~120F: lens barrel; 122: Front end; 124: Rear end; 130: Pressure-sensitive adhesive; 140: Adhesive; A1: Object side; A2: Image side; B: Included angle; C1, C2: Annular groove; D1, D2, Dinmax, Dinmin: Inner diameter; Dcvon, Dcvox, Dcv, Dbr: Outer diameter; D3, D4, Lc, Lps: Length; Ds: Depth; Lg: Distance; F1: First direction; Tcv: Thickness; Pbr: Circumference; Smin: Arc length; Wbr: Width; E: Reference plane; F1: Outer casing inlay structure; F2: Lens barrel inlay structure; G: Air gap; I: Optical axis; L: Lens; L1: First lens; M: Adhesive application area; N: Mating area; O11: Object-side opening of the outer cover; O12: Image-side opening of the outer cover; O21: Object-side opening of the lens barrel; O22: Image-side opening of the lens barrel; S11: Outer annular plane; S12: Inner annular conical surface; S13: Outer annular conical surface; S14: Cover mating surface; S21: Lens tube annular plane; S22: Outer surface; S3: Object side surface. Detailed Implementation

[0049] Figure 1 This is a cross-sectional schematic diagram of the optical imaging lens according to the first embodiment of the present invention. Please refer to... Figure 1 This embodiment provides an optical imaging lens 100, which includes an outer cover 110, a lens barrel 120, and a plurality of lenses L disposed within the lens barrel 120, extending along an optical axis I from an object side A1 to an image side A2. When light emitted from an object to be photographed enters the optical imaging lens 100 and passes through the plurality of lenses L and a filter, an image is formed on an image plane 99. In all embodiments disclosed herein, the number, shape, material, and type of the plurality of lenses L are not limited.

[0050] The lens barrel 120 includes a front end portion 122 near the object side A1 and a rear end portion 124 near the image side A2. Specifically, the front end portion 122 and the rear end portion 124 are defined to distinguish their relative positions, and the lens barrel 120 can be designed as a single piece without a clear boundary. The front end portion 122 includes a lens barrel object-side opening O21, and the rear end portion 124 includes a lens barrel image-side opening O22. The inner diameter D1 of the lens barrel object-side opening O21 is smaller than the inner diameter D2 of the lens barrel image-side opening O22. Therefore, it is not only beneficial for the outer cover 110, the lens barrel 120, and the multiple lenses L to be arranged sequentially for easy assembly, but also beneficial for reducing the volume of the optical imaging lens 100 while maintaining the wall thickness of the lens barrel 120. The front end portion 122 of the lens barrel 120 has a lens barrel annular plane S21 perpendicular to the optical axis I and located on a reference plane E, and an outer surface S22 facing away from the optical axis I.

[0051] The outer cover 110 is conical, specifically frustum-shaped, and is disposed on the outer surface S22 of the front end 122 of the lens barrel 120. The outer cover 110 includes an object-side opening O11 and an image-side opening O12. The maximum outer diameter of the object-side opening O11 (i.e., the minimum outer diameter Dcvon of the outer cover 110) is smaller than the maximum outer diameter of the image-side opening O12 (i.e., the maximum minimum outer diameter Dcvox of the outer cover 110). Therefore, the outer cover 110 helps to improve the strength of the front end 122 of the lens barrel 120. Furthermore, the conical shape of the outer cover 110 not only facilitates machining, but its placement on the outer surface S22 of the lens barrel 120 also disperses impact forces. Its chamfer-free design also reduces stress concentration, effectively preventing damage from external impacts or drops, thereby reducing the possibility of localized deformation and protecting the safety of internal components. The outer casing 110 has an annular plane S11 near the object side A1 and perpendicular to the optical axis I, an inner conical surface S12 adjacent to the annular plane S11 and facing the optical axis I, and an outer conical surface S13 adjacent to the annular plane S11 and away from the optical axis I. The inner conical surface S12 of the outer casing 110, in addition to reducing stray light generation, also enhances the strength of the object-side opening O11. The length D3 of the outer casing 110 on the optical axis I is greater than 40% of the length D4 of the lens barrel 120 on the optical axis I, which increases the protective area of ​​the lens barrel and also increases the bonding force between the outer casing 110 and the lens barrel 120, thereby improving drop resistance.

[0052] In this embodiment, the optical imaging lens 100 further includes a pressure-sensitive adhesive (PSA) 130 disposed between the outer cover 110 and the lens barrel 120 to secure the outer cover 110 to the lens barrel 120. This increases the bonding strength, and the pressure-sensitive adhesive 130 provides cushioning, thus improving the optical imaging lens 100's resistance to drops.

[0053] In this embodiment, the angle B between the outer annular plane S11 and the outer conical surface S13 is between 100 and 110 degrees. This disperses the impact force and reduces stress concentration. In this embodiment, the angle B between the outer annular plane S11 and the outer conical surface S13 is, for example, 105 degrees.

[0054] In this embodiment, the outer cover 110 is made of metal, which provides the optical imaging lens 100 with high strength and hardness, and good impact resistance.

[0055] In this embodiment, the outer cover 110 contacts the annular plane S21 of the lens barrel 120. Therefore, the outer cover 110 can cover the front end of the lens barrel 120, increasing the impact resistance of the front end 122 of the lens barrel 120.

[0056] Furthermore, the relationships between the important parameters in the optical imaging lens 100 of the first embodiment are as follows: Figure 9 As shown.

[0057] in, Tcv is the thickness of the outer casing 110 on the reference plane E; Wbr is the width of the annular plane S21 of the lens barrel on the reference plane E; Dcv is the maximum outer diameter of the outer casing 110 on the reference plane E; Dbr is the maximum outer diameter of the lens barrel 120 on the reference plane E; Dinmax is the maximum inner diameter of the inner ring conical surface S12; Dinmin is the minimum inner diameter of the inner ring conical surface S12; Dcvox is the maximum outer diameter of the outer casing 110; Dcvon is the minimum outer diameter of the outer casing 110; Pbr is the minimum circumference of the object-side opening O21 in the microscope tube; Smin is the minimum arc length of one of the multiple dispensing areas M closest to the object side A1.

[0058] Figure 2 This is a cross-sectional schematic diagram of the optical imaging lens according to the second embodiment of the present invention. Please refer to... Figure 2 The optical imaging lens 100A in this embodiment is similar to... Figure 1 The optical imaging lens 100 shown is different from the other two in that, in this embodiment, the outer cover 110A and the lens barrel 120A are injection molded by inserts. In this embodiment, the outer cover 110A includes at least one outer cover insert structure F1, and the lens barrel 120A includes at least one lens barrel insert structure F2. The outer cover 110A is bonded to the lens barrel 120A by at least one outer cover insert structure F1 and at least one lens barrel insert structure F2. Therefore, compared with dispensing, this embodiment has one less step, thus simplifying the process, and the bonding strength of the insert injection is stronger than that of glue. For example, in this embodiment, the number of at least one outer cover insert structure F1 and at least one lens barrel insert structure F2 is the same, and the at least one lens barrel insert structure F2 is a raised structure and is adjacent to the image-side opening O12 of the outer cover. In this way, the bonding area can be further increased, and the bonding force of the outer cover 110A can be strengthened. In this embodiment, the angle B between the outer cover annular plane S11 and the outer cover conical surface S13 is 100 degrees. Furthermore, the relationships between the important parameters in the optical imaging lens 100A of the second embodiment are as follows: Figure 9 As shown.

[0059] Figure 3 This is a cross-sectional schematic diagram of the optical imaging lens according to the third embodiment of the present invention. Please refer to... Figure 3 The optical imaging lens 100B in this embodiment is similar to... Figure 1The optical imaging lens 100 shown is different from the other two in that, in this embodiment, the outer cover 110B and the lens barrel 120B are injection molded by inserts. In this embodiment, the outer cover 110B includes at least one outer cover insert structure F1, and the lens barrel 120B includes at least one lens barrel insert structure F2. The outer cover 110B is bonded to the lens barrel 120B by at least one outer cover insert structure F1 and at least one lens barrel insert structure F2. Therefore, compared with dispensing, this embodiment has one less step, thus simplifying the process, and the bonding strength of the insert injection is stronger than that of glue. For example, in this embodiment, the number of at least one outer cover insert structure F1 and at least one lens barrel insert structure F2 is the same, and the at least one lens barrel insert structure F2 is a raised structure adjacent to the image-side opening O12 of the outer cover. In this way, the bonding area can be further increased, and the bonding force of the outer cover 110B can be strengthened. In addition, in this embodiment, the lens L closest to the object side A1 among the plurality of lenses L is the first lens L1, and the outer cover 110B contacts one object side S3 of the first lens L1. This shortens the length of the lens barrel 120B, thereby reducing the overall length of the optical imaging lens 100B and preventing the lens barrel 120B from directly contacting other substances and corroding. In this embodiment, the angle B between the annular plane S11 and the conical surface S13 of the outer cover is 105 degrees. Furthermore, the relationships between the important parameters in the optical imaging lens 100B of the third embodiment are as follows: Figure 9 As shown.

[0060] Figure 4 This is a cross-sectional schematic diagram of the optical imaging lens according to the fourth embodiment of the present invention. Please refer to... Figure 4 The optical imaging lens 100C in this embodiment is similar to... Figure 1 The optical imaging lens 100 shown is different from the other two in that, in this embodiment, the outer cover 110C and the lens barrel 120C are injection molded by inserts. In this embodiment, the outer cover 110C includes at least one outer cover insert structure F1, and the lens barrel 120C includes at least one lens barrel insert structure F2. The outer cover 110C is bonded to the lens barrel 120C by at least one outer cover insert structure F1 and at least one lens barrel insert structure F2. Therefore, compared with dispensing, this embodiment has one less step, thus simplifying the process, and the bonding strength of the insert injection is stronger than that of glue. For example, in this embodiment, the number of at least one outer cover insert structure F1 and at least one lens barrel insert structure F2 is the same, and the at least one lens barrel insert structure F2 is a groove structure located at the image-side opening O12 of the outer cover. In this way, the bonding area can be further increased, and the bonding force of the outer cover 110C can be strengthened. In addition, in this embodiment, the outer cover 110C can be made of a soft material with a Shore A hardness ranging from 70 to 90. In this embodiment, the angle B between the annular plane S11 and the conical surface S13 of the outer cover is 110 degrees. Furthermore, the relationships between the important parameters in the optical imaging lens 100C of the fourth embodiment are as follows: Figure 9As shown.

[0061] Figure 5 This is a cross-sectional schematic diagram of the optical imaging lens according to the fifth embodiment of the present invention. Figure 6 This is a front view schematic diagram of the optical imaging lens according to the fifth embodiment of the present invention. Please refer to... Figure 5 and Figure 6 The optical imaging lens 100D in this embodiment is similar to... Figure 1 The optical imaging lens 100 shown differs from the previous embodiment in that, in this embodiment, an air gap G is provided between the outer surface S22 of the front end portion 122 of the lens barrel 120D and the outer casing 110D. This air gap G acts as a buffer structure, preventing impact force from being directly transmitted to the front end portion 122 of the lens barrel 120D, thereby increasing its impact resistance. More specifically, the length of the air gap G along the optical axis I is 20% to 40% of the length of the outer casing 110D along the optical axis I. For example, in this embodiment, the length of the air gap G along the optical axis I is 30% of the length of the outer casing 110D along the optical axis I. This further improves the buffering capacity by designing the ratio of the air gap G to the length of the outer casing 110D, while also increasing assembly yield.

[0062] On the other hand, in this embodiment, the outer surface S22 of the lens barrel 120D is provided with a plurality of alternating adhesive dispensing areas M and a plurality of mating areas N. The number of adhesive dispensing areas M is the same as the number of mating areas N. More specifically, the number of adhesive dispensing areas M is at least 3 and at most 12. For example, in this embodiment, the outer surface S22 of the lens barrel 120D is provided with 6 alternating adhesive dispensing areas M and 6 mating areas N. This avoids the situation where the number of adhesive dispensing areas M is too small, resulting in an unstable bond between the outer cover 110D and the lens barrel 120D and the inability to improve dimensional accuracy, and also avoids the situation where the number of adhesive dispensing areas M is too large, resulting in a narrower width and reduced production efficiency. Each adhesive dispensing area M has a receiving groove for receiving adhesive, wherein the depth of the receiving groove is between 0.005 and 0.100 mm. The mating areas N directly contact the outer cover 110D. Furthermore, the relationship between the important parameters in the optical imaging lens 100D of the fifth embodiment is as follows: Figure 9 As shown.

[0063] Figure 7 This is a front view schematic diagram of the optical imaging lens according to the sixth embodiment of the present invention. Please refer to... Figure 7 For the sake of explanation, Figure 7 The outer casing is concealed. The optical imaging lens 100E of this embodiment is similar to... Figure 6The optical imaging lens 100D shown is different from the other two. In this embodiment, the outer surface S22 of the lens barrel 120E is provided with three alternating adhesive application areas M and three mating areas N. This avoids the problem of an insufficient number of adhesive application areas M leading to an unstable bond between the outer cover and the lens barrel 120E, which would prevent the lens from failing to improve dimensional accuracy, and also avoids the problem of an excessive number of adhesive application areas M resulting in a narrower width and reduced production efficiency. Furthermore, the relationships between the important parameters in the optical imaging lens 100E of the sixth embodiment are as follows: Figure 9 As shown.

[0064] Figure 8 This is a front view schematic diagram of the optical imaging lens according to the seventh embodiment of the present invention. Please refer to... Figure 8 For the sake of explanation, Figure 8 The outer casing is concealed. The optical imaging lens 100F of this embodiment is similar to... Figure 6 The optical imaging lens 100F shown is different from the other two. In this embodiment, the outer surface S22 of the lens barrel 120F is provided with 12 alternating adhesive application areas M and 12 mating areas N. This avoids the problem of an insufficient number of adhesive application areas M leading to an unstable bond between the outer casing and the lens barrel 120F, which would prevent the lens from failing to improve dimensional accuracy, and also avoids the problem of an excessive number of adhesive application areas M resulting in a narrower width and reduced production efficiency. Furthermore, the relationships between the important parameters in the optical imaging lens 100F of the sixth embodiment are as follows: Figure 9 As shown.

[0065] In addition, in the above embodiments, when the optical imaging lenses 100, 100A~100F satisfy the following condition: 0.450≦Tcv / Wbr≦1.400, by controlling the ratio of the width Wbr of the lens barrel annular plane S21 to the thickness Tcv of the outer cover 110, 110A~110D, it is beneficial to maintain the volume of the miniaturized lens, while ensuring the drop resistance of the optical imaging lenses 100, 100A~100F.

[0066] In addition, in the above embodiments, when the optical imaging lenses 100, 100A~100F satisfy the following condition: 1.120≦Dcv / Dbr≦1.201, by controlling the ratio of the maximum outer diameter Dbr of the lens barrel 120, 120A~120F to the maximum outer diameter Dcv of the outer cover 110, 110A~110D on the same plane, it is beneficial to maintain the volume of the miniaturized lens, while ensuring the drop resistance of the optical imaging lenses 100, 100A~100F.

[0067] In addition, in the above embodiments, when the optical imaging lenses 100, 100A~100F satisfy the following condition: 1.000≦Dinmax / Dinmin≦1.400, the slope of the conical surface S12 can be controlled by controlling the ratio of the maximum inner diameter Dinmax and the minimum inner diameter Dinmin of the inner ring conical surface S12 of the outer cover side opening O11, thereby achieving the effect of reducing stray light.

[0068] In addition, in the above embodiments, when the optical imaging lenses 100, 100A~100F satisfy the following condition: 1.150≦Dcvox / Dcvon≦1.500, the slope of the conical shape of the outer covers 110, 110A~110D can be controlled by the ratio of the maximum outer diameter Dcvox to the minimum outer diameter Dcvon of the outer covers 110, 110A~110D, thereby achieving the effect of controlling and dispersing impact force and reducing stress concentration.

[0069] In addition, in the fifth to seventh embodiments described above, the optical imaging lenses 100D, 100E, and 100F also satisfy the following condition: 3.100≦Pbr / Smin≦12.50, where Pbr is the minimum circumference of the object-side opening O21 of the lens barrel, and Smin is the minimum arc length of one of the multiple dispensing areas M closest to the object-side A1. In this way, the dispensing area can be adjusted by controlling the arc length of the dispensing area M, and with appropriate lens barrel dimensions 120D, 120E, and 120F, the deformation of the lens barrels 120D, 120E, and 120F can be improved, thereby increasing manufacturing yield.

[0070] Regarding the setting and selection of the adhesive in this embodiment, thermosetting adhesive is most commonly used in the industry for lens assembly. This is because thermosetting adhesive undergoes an irreversible chemical cross-linking reaction upon heating, transforming from a liquid to a solid. Therefore, after curing, it cannot be softened or melted again, exhibiting advantages such as high heat resistance and chemical resistance. These high heat and chemical resistance also facilitate passing high-temperature and low-temperature cyclic reliability tests. However, when the coefficient of thermal expansion of the lens barrel 120 is between 4 and 10 times that of the outer casing 110 (4≦CTEpc / CTEoc≦10), if the outer casing 110 is applied to the outer surface S22 of the front end 122 of the lens barrel 120 using thermosetting adhesive and undergoes a heating and curing process for a period of time (e.g., maintaining a temperature of 95°C for one hour), the space of the thermosetting adhesive will be compressed and reduced during the curing process because the thermal expansion of the lens barrel 120 is more than 4 times that of the outer casing 110. Therefore, during the process of the outer cover 110 and the lens barrel 120 returning to room temperature, the lens barrel 120, due to its expansion during heating, adheres to the outer cover 110, preventing it from returning to its original state. This results in stress tension and ultimately deformation of the lens barrel 120. Consequently, the deformation of the lens barrel 120 causes changes in the lens position, leading to various imaging quality problems such as lens eccentricity. On the other hand, since the light transmittance of the outer cover 110 is less than 10% (in this embodiment, it is, for example, metal), it is impossible to use general UV adhesive for bonding. Under the special requirements of drop resistance, thickness, and material limitations, using an adhesive that is solid at temperatures below 90°C and softens upon reheating to 50-75°C avoids the deformation of the lens barrel 120 caused by heat curing. Specifically, the colloid can be reactive polyurethane (RPU), which is solid below 90°C and becomes liquid when preheated to 90-120°C. It is injected through a syringe between the lens barrel 120 and the outer casing 110 and cured at room temperature (1-7 days), avoiding deformation of the lens barrel 120 caused by heat curing. It softens upon reheating to 50-75°C. The optimal melting point for reactive polyurethane is 110-120°C, which helps shorten the heating time to 30 minutes, thus reducing the process time. Moisture-curing adhesives are solid below 90°C and soften upon reheating to 50-75°C. In another embodiment, the colloid can be a UV-delayed curing adhesive, which is liquid at room temperature. It can be directly injected into the lens barrel 120 using a syringe and then irradiated with UV light before assembling the outer cover 110 and curing at room temperature (1-7 days). This avoids the problem of the outer cover 110 being opaque and unable to use general UV adhesives, and also avoids the problem of lens barrel 120 deformation caused by heat curing. The UV-delayed curing adhesive is solid at temperatures below 90°C and softens when reheated to 50-75°C.Among these, reactive polyurethane, compared to pressure-sensitive adhesive 130, has a higher yield in automated production because pressure-sensitive adhesive 130 is produced as a sheet and adhered to the conical surface S12, making it more prone to unevenness. Furthermore, regarding the choice of adhesive, although moisture-curing adhesives also avoid the heat curing process, because the adhesive is placed between the outer surface S22 of the outer housing 110 and the front end 122 of the lens barrel 120, the surface area exposed to air moisture is extremely small. Compared to reactive polyurethane and UV-delayed curing adhesives, which undergo chemical reactions such as heating or UV irradiation before bonding, moisture-curing adhesives require a longer curing time at room temperature, increasing the lens production cycle. Moreover, the extremely small surface area exposed to air moisture may also be a reason why it is difficult to pass the reliability test of cycling from -30℃ to 75℃. In summary, when reactive polyurethane or UV delayed-curing adhesive is bonded and cured on the outer surface S22 of the front end 122 of the lens barrel 120 and the outer housing 110, and in an environment meeting conditions such as 9.900≦Dcvon / Wbr≦15.500 and 4≦CTEpc / CTEoc≦10, it not only avoids the deformation problem caused by heat curing, improves the yield of automated production, and shortens the lens production time and cycle, but also facilitates the lens to pass the reliability test of cycling from -30℃ to 75℃, thus improving production quality and yield. The coefficients of thermal expansion of the lens barrel 120 or outer housing 110 made of different materials can be referenced below.

[0071]

[0072] Figure 10 This is a cross-sectional schematic diagram of the optical imaging lens according to the eighth embodiment of the present invention. Please refer to... Figure 10 The optical imaging lens 100G in this embodiment is similar to... Figure 1 The optical imaging lens 100 shown is different from the other two. In this embodiment, the outer cover 110 has a cover bonding surface S14, and the lens barrel 120 and the outer cover 110 are bonded together by applying adhesive between the outer surface S22 of the front end of the lens barrel 120 and the cover bonding surface S14 of the outer cover 110. For example, adhesive 140 (such as thermosetting adhesive, hot melt adhesive, etc.) or pressure-sensitive adhesive 130 of the aforementioned embodiment can be used. The present invention is not limited to these. It is worth mentioning that the cover bonding surface S14 has multiple annular grooves C1. In this way, the annular grooves C1 can increase the volume of adhesive 140 and increase the contact area between the cover bonding surface S14 and adhesive 140, thereby increasing the bonding force between the dissimilar materials of the lens barrel 120 and the outer cover 110, preventing separation due to drops, and thus preventing deformation or damage to the lens barrel 120. In another embodiment, the annular grooves C1 can be threaded grooves, so that multiple groove-like structures are spaced apart on the cross-section parallel to the optical axis I. The present invention is also not limited to this.

[0073] Furthermore, the relationships between the important parameters in the optical imaging lens 100G of the eighth embodiment are as follows: Figure 14 As shown.

[0074] in, Ds is the maximum depth of the annular groove C1; Ls is the maximum length of each annular groove C1 in the first direction F1; Lc is the minimum length of the cover mating surface S14 from the outer cover side opening O11 to the outer cover image side opening O12; Lps is the minimum length between any two adjacent elements in the annular groove C1; n is the number of annular grooves C1.

[0075] Figure 11 This is a cross-sectional schematic diagram of the optical imaging lens according to the ninth embodiment of the present invention. Please refer to... Figure 11 The optical imaging lens 100H in this embodiment is similar to... Figure 10 The optical imaging lens 100G shown is different from the other two. In this embodiment, the lens barrel 120 also has multiple annular grooves C2 similar to the annular groove C1 of the outer cover 110, and the positions of the multiple annular grooves C1 of the outer cover 110 correspond to the positions of the multiple annular grooves C2 of the lens barrel 120. In this way, the volume of the adhesive 140 and the contact area between the cover mating surface S14 and the adhesive 140 can be increased by the annular grooves C1 and C2, thereby increasing the bonding force between the lens barrel 120 and the outer cover 110, which are made of different materials, and preventing them from separating due to drops, thus preventing deformation or damage to the lens barrel 120. In addition, the relationship between the important parameters in the optical imaging lens 100H of the ninth embodiment is as follows: Figure 14 As shown.

[0076] Figure 12 This is a cross-sectional schematic diagram of the optical imaging lens according to the tenth embodiment of the present invention. Please refer to... Figure 12 The optical imaging lens 100I in this embodiment is similar to... Figure 10 The optical imaging lens 100G shown is different from the other two. In this embodiment, the lens barrel 120 also has multiple annular grooves C2 similar to the annular groove C1 of the outer cover 110, and the positions of the multiple annular grooves C1 of the outer cover 110 and the multiple annular grooves C2 of the lens barrel 120 are staggered. In this way, the volume of the adhesive 140 and the contact area between the cover mating surface S14 and the adhesive 140 can be increased by the annular grooves C1 and C2, thereby increasing the bonding force between the lens barrel 120 and the outer cover 110, which are made of different materials, and preventing them from separating due to drops, thus preventing deformation or damage to the lens barrel 120. In addition, the relationship between the important parameters in the optical imaging lens 100I of the tenth embodiment is as follows: Figure 14 As shown.

[0077] Figure 13 This is a cross-sectional schematic diagram of the optical imaging lens according to the eleventh embodiment of the present invention. Please refer to... Figure 13 The optical imaging lens 100J in this embodiment is similar to... Figure 10 The optical imaging lens 100G shown differs from the other embodiment in that, in this embodiment, the lens barrel 120 has an annular groove C2. If the direction from the outer cover side opening O11 to the outer cover image side opening O12 along the cover mating surface S14 is defined as the first direction F1, then the bottom of this annular groove C2 extends flatly along the first direction F1. In this way, the annular grooves C1 and C2 increase the volume of the adhesive 140 and the contact area between the cover mating surface S14 and the adhesive 140, thereby increasing the bonding force between the lens barrel 120 and the outer cover 110, which are made of different materials, preventing separation due to drops, and thus preventing deformation or damage to the lens barrel 120. Furthermore, the relationships between the important parameters in the optical imaging lens 100J of the eleventh embodiment are as follows: Figure 14 As shown.

[0078] In addition, in the above-described eighth to eleventh embodiments, when the optical imaging lenses 100G~100J satisfy the following condition: 2.600≦Tcv / Ds≦6.000, a better ratio of the thickness Tcv of the outer cover 110 to the depth Ds of the annular groove C1 can be obtained. This avoids the annular groove C1 being too shallow, which would prevent the glue 140 from being effectively increased, thus failing to achieve the purpose of increasing the bonding force. Alternatively, if the annular groove C1 is too deep, it may cause the outer cover 110 to be locally too thin, thereby losing its function of protecting the lens barrel 120.

[0079] Furthermore, due to the small size of the optical imaging lens 100G, and the even smaller size at the end near the outer cover side opening O11, its structural strength is relatively low. Therefore, in the above-described eighth to eleventh embodiments, the minimum distance Lg from the outer cover side opening O11 to the annular groove C1 of the outer cover 110 can be designed to be between 0.550 and 0.700 mm. By maintaining the distance Lg from the outer cover side opening O11 to the annular groove C1, the overall structural strength of the outer cover side opening O11 end is maintained, preventing the outer cover 110 from deforming due to drops and losing its function of protecting the lens barrel 120.

[0080] In addition, in the above-mentioned eighth to eleventh embodiments, when the optical imaging lens 100G~100J satisfies the following condition: 2.800≦Lc / (n*Ls)≦4.700, the annular groove C1 can be designed according to a better ratio to avoid the overall area of ​​the annular groove C1 occupying too high a proportion of the cover mating surface S14, which would reduce the overall strength of the outer cover 110, and to avoid the annular groove C1 occupying too low a proportion of the cover mating surface S14, which would not effectively increase the contact area between the cover mating surface S14 and the adhesive 140, thus failing to achieve the purpose of increasing the bonding force.

[0081] On the other hand, in the above-described eighth to eleventh embodiments, these annular grooves C1 are arranged periodically. By arranging them periodically, the annular grooves C1 can be evenly distributed on the cover mating surface S14, thereby increasing the contact area between the cover mating surface S and the adhesive 140, and thus better improving the bonding force between the outer cover 110 and the lens barrel 120, which are made of different materials.

[0082] In addition, in the above-mentioned eighth to eleventh embodiments, when the optical imaging lens 100G satisfies the following condition: 2.300≦Lc / (n*Lps)≦29.000, the annular groove C1 can be designed according to a better ratio to avoid the annular groove C1 occupying too high a proportion of the cover bonding surface S14 per unit area, which would reduce the strength of the outer cover 110 in some areas, and to avoid the annular groove C1 occupying too low a proportion of the cover bonding surface S14 in some areas, which would not effectively cover the contact area between the cover bonding surface S14 and the adhesive 140, thus failing to achieve the purpose of increasing the bonding force.

[0083] In summary, the optical imaging lens of the present invention comprises an outer casing, a lens barrel, and a plurality of lenses disposed within the lens barrel along an optical axis from the object side to the image side. The front end of the lens barrel includes an object-side opening, and the rear end includes an image-side opening, with the inner diameter of the object-side opening being smaller than that of the image-side opening. Therefore, this arrangement not only facilitates assembly by sequentially arranging the outer casing, lens barrel, and multiple lenses, but also reduces the overall size of the optical imaging lens while maintaining the lens barrel's wall thickness. Furthermore, the outer casing includes an object-side opening and an image-side opening, with the maximum outer diameter of the object-side opening being smaller than that of the image-side opening. This outer casing enhances the strength of the front end of the lens barrel. Additionally, the length of the outer casing along the optical axis is greater than 40% of the length of the lens barrel along the optical axis. This increases the protective area of ​​the lens barrel and the bonding strength between the outer casing and the lens barrel, thereby improving drop resistance. Furthermore, the conical shape of the outer casing not only facilitates machining but also disperses impact force when placed on the outer surface of the lens barrel. Its chamfer-free design reduces stress concentration, effectively preventing damage from external impacts or drops, thus minimizing the possibility of localized deformation and protecting internal components. In addition, the optical imaging lens satisfies the following condition: 0.450≦Tcv / Wbr≦1.400, where Tcv is the thickness of the outer casing on the reference plane, and Wbr is the width of the annular plane of the lens barrel on the reference plane. Therefore, by controlling the ratio of the width of the annular plane of the lens barrel to the thickness of the outer casing, it is beneficial to maintain the miniaturized size of the lens while ensuring the optical imaging lens's resistance to drops.

[0084] Although the present invention has been disclosed above by way of embodiments, it is not intended to limit the present invention. Anyone skilled in the art can make some modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. An optical imaging lens, comprising an outer casing, a lens barrel, and a plurality of lenses disposed within the lens barrel along an optical axis from an object side to an image side, wherein, The microscope tube includes a front end portion near the object side and a rear end portion near the image side; The front end includes an object-side opening of the lens barrel, and the rear end includes an image-side opening of the lens barrel. The inner diameter of the object-side opening of the lens barrel is smaller than the inner diameter of the image-side opening of the lens barrel. The front end of the lens barrel has a lens barrel annular plane that is perpendicular to the optical axis and located on a reference plane; The outer cover is conical and is disposed on the outer surface of the front end of the lens barrel; The outer cover includes an outer cover side opening and an outer cover image side opening, wherein the maximum outer diameter of the outer cover side opening is smaller than the maximum outer diameter of the outer cover image side opening; The outer cover has an outer cover annular plane that is close to the object and perpendicular to the optical axis, an inner ring conical surface adjacent to the outer cover annular plane, and an outer cover conical surface; The length of the outer casing along the optical axis is greater than 40% of the length of the lens barrel along the optical axis; and The optical imaging lens satisfies the following condition: 0.450≦Tcv / Wbr≦1.400, where Tcv is the thickness of the outer cover on the reference plane, and Wbr is the width of the annular plane of the lens barrel on the reference plane.

2. The optical imaging lens as described in claim 1 further includes a pressure-sensitive adhesive disposed between the outer cover and the lens barrel.

3. The optical imaging lens as claimed in claim 1, wherein the outer cover includes at least one outer cover inlay structure, the lens barrel includes at least one lens barrel inlay structure, and the outer cover is combined with the at least one lens barrel inlay structure of the lens barrel by the at least one outer cover inlay structure.

4. The optical imaging lens as claimed in claim 3, wherein the number of the at least one outer cover inlay structure is the same as the number of the at least one lens barrel inlay structure, the at least one lens barrel inlay structure is a protruding structure and is adjacent to the image-side opening of the outer cover.

5. An optical imaging lens, comprising an outer casing, a lens barrel, and a plurality of lenses disposed within the lens barrel along an optical axis from an object side to an image side, wherein, The material of the outer cover is different from the material of the lens barrel; The microscope tube includes a front end portion near the object side and a rear end portion near the image side; The front end includes an object-side opening of the lens barrel, and the rear end includes an image-side opening of the lens barrel. The inner diameter of the object-side opening of the lens barrel is smaller than the inner diameter of the image-side opening of the lens barrel. The front end of the lens barrel has a lens barrel annular plane that is perpendicular to the optical axis and located on a reference plane; The outer cover is conical and is disposed on the outer surface of the front end of the lens barrel; The outer cover includes an outer cover side opening and an outer cover image side opening, wherein the maximum outer diameter of the outer cover side opening is smaller than the maximum outer diameter of the outer cover image side opening; The outer cover has a cover mating surface, and the lens barrel and the outer cover are joined together by applying adhesive between the outer surface and the cover mating surface. The cover mating surface has multiple annular grooves. The optical imaging lens satisfies the following condition: 2.600≦Tcv / Ds≦6.000, where Tcv is the thickness of the outer cover on the reference plane, and Ds is the maximum depth of the annular grooves.

6. The optical imaging lens of claim 5, wherein the minimum distance from the outer cover side opening to the annular grooves is between 0.550 and 0.700 mm.

7. The optical imaging lens of claim 5, wherein the optical imaging lens satisfies the following condition: 2.800≦Lc / (n*Ls)≦4.700, the first direction is from the outer cover side opening to the outer cover image side opening along the cover mating surface, where Lc is the minimum length of the cover mating surface from the outer cover side opening to the outer cover image side opening, Ls is the maximum length of each of the annular grooves in the first direction, and n is the number of the annular grooves.

8. The optical imaging lens of claim 5, wherein the annular grooves are periodically arranged.

9. The optical imaging lens of claim 5, wherein the optical imaging lens satisfies the following condition: 2.300≦Lc / (n*Lps)≦2.900, where Lc is the minimum length of the cover mating surface from the outer cover side opening to the outer cover image side opening, Lps is the minimum length between any two adjacent annular grooves, and n is the number of annular grooves.

10. The optical imaging lens as claimed in claim 1 or 5, further comprising a gel disposed between the outer cover and the lens barrel.

11. The optical imaging lens of claim 1 or 5, wherein one of the plurality of lenses closest to the object side is a first lens, and the outer cover contacts one object side of the first lens.

12. The optical imaging lens as claimed in claim 1 or 5, wherein the angle between the annular plane of the outer cover and the conical surface of the outer cover is between 100 and 110 degrees.

13. The optical imaging lens as claimed in claim 1 or 5, wherein the outer casing is made of metal.

14. The optical imaging lens as claimed in claim 1 or 5, wherein the outer casing may be a soft material having a Shore A hardness in the range of 70 to 90.

15. The optical imaging lens as claimed in claim 1 or 5, wherein the outer casing contacts the annular plane of the lens barrel.

16. The optical imaging lens as claimed in claim 1 or 5, wherein the optical imaging lens satisfies the following condition: 1.120≦Dcv / Dbr≦1.201, where Dcv is the maximum outer diameter of the shroud on the reference plane, and Dbr is the maximum outer diameter of the lens barrel on the reference plane.

17. The optical imaging lens as claimed in claim 1 or 5, wherein the optical imaging lens satisfies the following condition: 1.000≦Dinmax / Dinmin≦1.400, where Dinmax is the maximum inner diameter of the inner ring conical surface and Dinmin is the minimum inner diameter of the inner ring conical surface.

18. The optical imaging lens as claimed in claim 1 or 5, wherein the optical imaging lens satisfies the following condition: 1.150≦Dcvox / Dcvon≦1.500, where Dcvox is the maximum outer diameter of the housing and Dcvon is the minimum outer diameter of the housing.

19. The optical imaging lens as claimed in claim 1 or 5, wherein an air gap is formed between the outer surface of the front end portion of the lens barrel and the outer cover.

20. The optical imaging lens of claim 19, wherein the length of the air gap on the optical axis is 20% to 40% of the length of the outer cover on the optical axis.

21. The optical imaging lens as claimed in claim 1 or 5, wherein the outer surface of the lens barrel is provided with a plurality of dispensing areas and a plurality of mating areas arranged alternately, the number of dispensing areas being the same as the number of mating areas, each dispensing area having a receiving groove for receiving adhesive, wherein the depth of the receiving groove is between 0.005 and 0.100 mm, and the mating areas are in direct contact with the outer cover.

22. The optical imaging lens of claim 21, wherein the number of the adhesive dots is at least 3 and at most 12.

23. The optical imaging lens of claim 21, wherein the optical imaging lens satisfies the following condition: 3.100≦Pbr / Smin≦12.50, where Pbr is the minimum circumference of the object-side opening of the lens barrel, and Smin is the minimum arc length of one of the dispensing areas closest to the object side.

24. The optical imaging lens as claimed in claim 1 or 5, wherein the optical imaging lens satisfies the following condition: 4≦CTEpc / CTEoc≦10, where CTEpc is the coefficient of thermal expansion of the lens barrel and CTEoc is the coefficient of thermal expansion of the outer casing.

25. The optical imaging lens of claim 10, wherein the colloid is solid at temperatures below 90°C and softens when reheated to 50-75°C.

Images