Optical imaging lens

Abstract

This invention discloses an optical imaging lens, comprising a metal cap, a plastic lens barrel, and a plurality of lenses disposed within the plastic lens barrel along an optical axis from an object side to an image side. The plastic lens barrel includes a fixed surface facing the object side and a light-transmitting portion near the object side. The lens closest to the object side is a first lens, with one object-side surface of the first lens located between the object side and the fixed surface. The metal cap is disposed on the fixed surface and forms a light-transmitting aperture. A clearance gap exists between the light-transmitting portion and the first lens.

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 products are changing rapidly, and their key components - optical imaging lenses - are also becoming more diversified. Among them, the front-facing camera of mobile phones is gradually becoming fully integrated into the screen, so the demand for miniaturization of the lens head size is becoming increasingly strong.

[0003] Due to the limitations of optical parameters (F / NO, EFL, and aperture size) and the molding constraints of the plastic lens barrel, miniaturization of the lens head using conventional barrel designs is difficult. Miniaturization often results in stray light generation and increased assembly complexity, presenting challenges for the industry. Current technology using a one-piece plastic lens barrel limits the front-end wall thickness to approximately ≥0.20mm, preventing further thinning. Furthermore, thin plastic often suffers from insufficient structural strength due to its mechanical properties. While retracting the lens head and applying a light-shielding coating directly to the exposed lens edge can significantly reduce head size, capillary action and lens surface roughness can affect the actual coating area, leading to discrepancies between the actual coating area and the ideal design. This can also result in damage from drops, breakage, or environmental degradation. Therefore, designing an ultra-compact optical imaging lens that effectively blocks stray light, improves assembly ease, and maintains high reliability is a problem the industry currently needs to solve. Summary of the Invention

[0004] This invention provides an optical imaging lens that can block stray light, improve assembly convenience, and has good reliability. It is an ultra-compact head-sized optical imaging lens that overcomes the coating reliability problem of prior art.

[0005] This invention provides an optical imaging lens, comprising a metal cap, a plastic lens barrel, and a plurality of lenses disposed within the plastic lens barrel along an optical axis from an object side to an image side. The plastic lens barrel includes a fixed surface facing the object side and a light-transmitting portion near the object side. The lens closest to the object side is a first lens, with one object-side surface of the first lens located between the object side and the fixed surface. The metal cap is disposed on the fixed surface and forms a light-transmitting aperture. A clearance gap exists between the light-transmitting portion and the first lens. The optical imaging lens satisfies the following conditions: 0.400≤(Dcmax-Dbo) / (Dcmax-D1min)≤1.000 and 1.000≤Dco / D1min≤1.100, where Dcmax is the maximum outer diameter of the metal cap, Dbo is the inner diameter of the light-transmitting portion closest to the object side, D1min is the minimum outer diameter of the first lens closest to the object side, and Dco is the outer diameter of the metal cap closest to the object side.

[0006] In one embodiment of the present invention, the optical imaging lens described above satisfies the following condition: 0.450≤(Dcmax-Dbo) / (Dcmax-Dci)≤1.000, where Dci is the outer diameter of one side wall of the metal cap closest to the image side.

[0007] In one embodiment of the present invention, the optical imaging lens described above satisfies the following condition: 1.200≤Dcmax / Dbo≤1.550.

[0008] In one embodiment of the present invention, the optical imaging lens described above satisfies the following condition: 0.450≤(Dcmax-Dbo) / (Dcmax-D1pmax)≤1.000, where D1pmax is the maximum outer diameter of the first lens in the extension direction of the fixed surface.

[0009] In one embodiment of the present invention, the optical imaging lens described above satisfies the following condition: Dco / Dbmax≤0.320, where Dbmax is the maximum outer diameter of the plastic lens barrel.

[0010] In one embodiment of the present invention, the optical imaging lens described above satisfies the following condition: Dcmax / Dco≥1.600.

[0011] In one embodiment of the present invention, the optical imaging lens described above satisfies the following condition: 0°≤α≤10°, where α is the angle between an outer surface of one side wall of the metal cap and the optical axis.

[0012] In one embodiment of the present invention, the overall thickness of the metal cap is uniform and equal.

[0013] In one embodiment of the present invention, the optical imaging lens described above satisfies the following condition: 0.024mm≤Tm≤0.030mm, where Tm is the thickness of the metal cap.

[0014] In one embodiment of the present invention, the material of the aforementioned metal cap includes stainless steel or phosphor bronze.

[0015] In one embodiment of the present invention, the aforementioned metal cap is adhered to the plastic lens barrel with thermosetting adhesive.

[0016] In one embodiment of the present invention, the metal cap has a lens barrel connecting surface that contacts the fixing surface and an object side plane that is parallel to the lens barrel connecting surface. The optical imaging lens satisfies the following condition: 0.000mm≤Pc≤0.005mm, where Pc is the parallelism between the lens barrel connecting surface and the object side plane.

[0017] In one embodiment of the present invention, the surface of the metal cap is black.

[0018] In one embodiment of the present invention, the surface of the first lens connection clearance gap has a blackened structure.

[0019] In one embodiment of the present invention, the aforementioned metal cap has a tapered surface at the edge adjacent to the light-transmitting aperture, which tapers from the object side to the image side to the light-transmitting aperture. The optical imaging lens satisfies the following condition: 50°≤β≤60°, where β is the angle between the tapered surface extending to the optical axis and the optical axis.

[0020] In one embodiment of the present invention, the aforementioned metal cap has a tapered surface at the edge adjacent to the light-transmitting aperture, and the tapered surface is an arc surface.

[0021] Based on the above, in the optical imaging lens of the present invention, for miniaturization purposes, the optical imaging lens includes a metal cap, a plastic lens barrel, and a plurality of lenses disposed within the plastic lens barrel along an optical axis from the object side to the image side. The plastic lens barrel includes a fixed surface facing the object side and a light-transmitting portion near the object side. The lens closest to the object side is a first lens, and the object-side surface of the first lens is located between the object side and the fixed surface. Specifically, the object-side portion of the relatively large plastic lens barrel is recessed, exposing the first lens. A clearance gap exists between the light-transmitting portion and the first lens. The metal cap is disposed on the fixed surface and forms a light-transmitting aperture. Therefore, by using the metal cap to block unwanted light from entering the clearance gap and protecting the exposed portion of the first lens, the reliability problem of the surface coating is overcome. Furthermore, the optical imaging lens satisfies the following conditions: 0.400≤(Dcmax-Dbo) / (Dcmax-D1min)≤1.000 and 1.000≤Dco / D1min≤1.100, where Dcmax is the maximum outer diameter of the metal cap, Dbo is the inner diameter of the light-transmitting part closest to the object side, D1min is the minimum outer diameter of the first lens closest to the object side, and Dco is the outer diameter of the metal cap closest to the object side. Therefore, when considering the fixing strength between the cap and the lens barrel and the clearance relationship between the light-transmitting part of the lens barrel and the lens, meeting the condition 0.400≤(Dcmax-Dbo) / (Dcmax-D1min)≤1.000 allows for better adhesion even with a larger clearance, increasing the structural strength of the light-transmitting part. It is less susceptible to deformation, wear, or detachment due to external forces, while simultaneously sealing the clearance to block stray light. Furthermore, when the metal cap on the fixed surface satisfies 1.000≤Dco / D1min≤1.100 relative to the outer diameter of the lens protrusion, the radial volume of the head can be effectively reduced. The material strength and ductility of metal are beneficial for the manufacture of thin components, facilitating fine-tuning of the shape while ensuring reliability. For example, directly forming the aperture can reduce the assembly of additional micro-components, improve assembly ease, reduce the accumulation of assembly tolerances, meet coaxiality requirements, and increase lens reliability.

[0022] To make the above features and advantages of the present invention more apparent and understandable, specific embodiments are described below in conjunction with the accompanying drawings for detailed explanation. Attached Figure Description

[0023] Figure 1 This is a three-dimensional schematic diagram of the optical imaging lens according to the first embodiment of the present invention.

[0024] Figure 2 for Figure 1 A front view diagram of an optical imaging lens.

[0025] Figure 3 for Figure 1 A three-dimensional exploded diagram of an optical imaging lens.

[0026] Figure 4 for Figure 1 A cross-sectional schematic diagram of an optical imaging lens.

[0027] Figure 5 for Figure 4 A magnified schematic diagram of a portion of the optical imaging lens.

[0028] Figure 6 This is a cross-sectional schematic diagram of the optical imaging lens according to the second embodiment of the present invention.

[0029] Figure 7 This is a cross-sectional schematic diagram of the optical imaging lens according to the third embodiment of the present invention.

[0030] Figure 8 The numerical values ​​of the important parameters and their relationships of the optical imaging lenses of the first to third embodiments of the present invention are shown.

[0031] Explanation of reference numerals in the attached figures:

[0032] 100, 100A~100B: Optical imaging lenses;

[0033] 110: Metal cap; 112: Side wall; 114: Beveled corner; 120: Plastic lens barrel; 122: Light transmission section;

[0034] A1: Object side; A2: Image side;

[0035] B: Blackened structure;

[0036] D1min: minimum outer diameter; Dbmax, Dcmax, D1pmax: maximum outer diameter; Dbo: inner diameter; Dci, Dco: outer diameter;

[0037] G: clearance; I: optical axis; L: lens; L1: first lens; O1: aperture; S1: object side surface;

[0038] S11: Lens tube connecting surface; S12: Object side plane; S13: Tapered surface; S14: Outer surface; S21: Fixing surface;

[0039] Pc: Parallelism; Tm: Thickness; α, β: Angles. Detailed Implementation

[0040] Please refer to Figures 1 to 4 This embodiment provides an optical imaging lens 100, which includes a metal cap 110, a plastic lens barrel 120, and a plurality of lenses L disposed within the plastic lens barrel 120, extending along an optical axis I from an object side A1 to an image side A2. It should be noted that, for the sake of simplicity, Figure 4 The detailed structure of the multiple lenses L is omitted. When light emitted from an object to be photographed enters the optical imaging lens 100 and passes through the multiple lenses L and filters, an image is formed on an image plane. In all embodiments disclosed herein, the number, shape, material, and type of the multiple lenses L are not limited.

[0041] The plastic lens barrel 120 includes a fixed surface S21 facing the object side A1 and a light-transmitting portion 122 near the object side A1. Among the plurality of lenses L, the one closest to the object side A1 is a first lens L1, and the object-side surface S1 of the first lens L1 is located between the object side A1 and the fixed surface S21. In this way, the bulky portion of the plastic lens barrel 120 facing the image side A2 can be retracted, allowing the first lens L1 to protrude from the plastic lens barrel 120, thereby achieving miniaturization. Furthermore, a clearance gap G exists between the light-transmitting portion 122 of the plastic lens barrel 120 and the first lens L1, and the surface of the first lens L1 connecting to the clearance gap G has a blackened structure, such as a coating or ink (e.g., Figure 5 The blackened structure B shown is used to shield or absorb stray light, reduce stray light entering the optically effective area, and allow the clearance gap G to avoid assembly interference between the plastic lens barrel 120 and the blackened structure B, thus reducing coaxiality issues.

[0042] Figure 5 for Figure 4 A partially enlarged schematic diagram of the optical imaging lens. Please also refer to... Figure 4 and Figure 5A metal cap 110 is disposed on the fixing surface S21 of the plastic lens barrel 120 and forms a light-transmitting aperture O1. The metal cap 110 has a lens barrel connecting surface S11 that contacts the fixing surface S21 of the plastic lens barrel 120 and an object-side plane S12 parallel to the lens barrel connecting surface S11. Therefore, the exposed portion of the first lens L1 can be shielded and protected by the metal cap 110, overcoming the coating reliability problem. Specifically, the metal cap 110 includes a sidewall portion 112 bent toward the object side A1 and a chamfered portion 114 located at one end of the sidewall portion 112 toward the object side A1 and bent toward the optical axis I. In this embodiment, the metal cap 110 has a tapered surface S13 (i.e., the surface of the chamfered portion 114 toward the optical axis I) near the edge of the light-transmitting aperture O1. Therefore, it is beneficial to reflect stray light and reduce stray light entering the optically effective area. In a preferred embodiment, the tapered surface S13 is an arc surface.

[0043] Furthermore, the metal cap 110 is made of metal, whose strength and ductility are beneficial for the manufacture of thin components. While ensuring reliability, it also facilitates fine-tuning of the shape, such as directly forming an aperture, reducing the need for assembling additional micro-components. In this embodiment, the overall thickness of the metal cap 110 is uniform. Therefore, it improves assembly accuracy and manufacturing convenience. In this embodiment, the metal cap 110 is made of stainless steel or phosphor bronze. Therefore, it improves the durability and corrosion resistance of the metal cap 110, provides good mechanical properties, and is easier to process. In this embodiment, the surface of the metal cap 110 is black. Therefore, it helps to block or absorb stray light, reducing stray light entering the optically effective area. In this embodiment, during assembly, the metal cap 110 is adhered to the plastic lens barrel 120 with thermosetting adhesive. This improves adhesion and eliminates the need for ultraviolet light.

[0044] In the optical imaging lens 100 of the first embodiment, the thickness Tm of the metal cap 110 is 0.024 mm, the angle α between the outer surface S14 of the side wall portion 112 of the metal cap 110 and the optical axis I is 10°, and the tapered surface S13 of the metal cap 110 extends to the point where the angle β between the optical axis I and the optical axis I is 50°.

[0045] Furthermore, the relationships between the important parameters in the optical imaging lens 100 of the first embodiment are as follows: Figure 8 As shown.

[0046] in,

[0047] Dcmax is the maximum outer diameter of the metal cap 110;

[0048] Dbo is the inner diameter of the light-transmitting part 122 of the plastic lens barrel 120 closest to the object side A1;

[0049] D 1min is the smallest outer diameter of the first lens L1 closest to the object side A1;

[0050] Dco is the outer diameter of the metal cap 110 closest to the object side A1;

[0051] Dci is the outer diameter of the side wall portion 112 of the metal cap 110 closest to the image side A2;

[0052] D1pmax is the maximum outer diameter of the first lens L1 in the extension direction of the fixed surface S21 of the plastic lens barrel 120;

[0053] Dbmax is the maximum outer diameter of the 120mm plastic lens barrel;

[0054] Tm is the thickness of the metal cap 110;

[0055] Pc is the parallelism between the lens barrel connecting surface S11 of the metal cap 110 and the object side plane S12;

[0056] α is the angle between an outer surface S14 of the sidewall portion 112 of the metal cap 110 and the optical axis I; and

[0057] β is the angle between the tapered surface S13 of the metal cap 110 and the optical axis I.

[0058] Figure 6 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 6 A second embodiment of the optical imaging lens 100A of the present invention is generally similar to the optical imaging lens 100 of the first embodiment, but the differences between the two are as follows: the structural parameters of various optical data, metal cap 110 and plastic lens barrel 120 are more or less different.

[0059] In the optical imaging lens 100A of the second embodiment, the thickness Tm of the metal cap 110 is 0.025 mm, the angle α between the outer surface S14 of the side wall portion 112 of the metal cap 110 and the optical axis I is 5°, and the tapered surface S13 of the metal cap 110 extends to the point where the angle β between the optical axis I and the optical axis I is 55°.

[0060] Furthermore, the relationships between the important parameters in the optical imaging lens 100A of the second embodiment are as follows: Figure 8 As shown.

[0061] Figure 7 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 7 A third embodiment of the optical imaging lens 100B of the present invention is generally similar to the optical imaging lens 100 of the first embodiment, but the differences between the two are as follows: the structural parameters of various optical data, metal cap 110 and plastic lens barrel 120 are more or less different.

[0062] In the optical imaging lens 100B of the third embodiment, the thickness Tm of the metal cap 110 is 0.030 mm, the outer surface S14 of the side wall portion 112 of the metal cap 110 has an angle α of 0° with the optical axis I, and the tapered surface S13 of the metal cap 110 extends to an angle β of 60° between the optical axis I and the optical axis I.

[0063] Furthermore, the relationships between the important parameters in the optical imaging lens 100B of the third embodiment are as follows: Figure 8 As shown.

[0064] In addition, in the above embodiments, considering the fixing strength between the metal cap 110 and the plastic lens barrel 120, and the relationship between the light-transmitting part 122 of the plastic lens barrel 120 and the clearance gap G between the first lens L1, when the optical imaging lenses 100, 100A, and 100B satisfy the condition 0.400≤(Dcmax-Dbo) / (Dcmax-D 1min)≤1.000, they can maintain better adhesion even with a larger clearance gap G, and are less prone to deformation, wear, or detachment due to external forces. Simultaneously, closing the clearance gap G blocks stray light. In a preferred embodiment, the optical imaging lenses 100, 100A, and 100B satisfy the condition 0.430≤(Dcmax-Dbo) / (Dcmax-D 1min)≤0.800, but the present invention is not limited thereto.

[0065] In addition, in the above embodiments, the metal cap 110 disposed on the fixing surface S21 of the plastic lens barrel 120, when the minimum outer diameter of the outer diameter closest to the object side A1 protruding from the first lens L1 satisfies: 1.000≤Dco / D1min≤1.100, can effectively reduce the radial volume of the head of the optical imaging lens 100. In a preferred embodiment, the optical imaging lenses 100, 100A, and 100B satisfy the condition 1.040≤Dco / D1min≤1.090, but the present invention is not limited thereto.

[0066] In addition, in the above embodiments, when the optical imaging lenses 100, 100A, and 100B satisfy the following conditions: 0.450≤(Dcmax-Dbo) / (Dcmax-Dci)≤1.000, 1.200≤Dcmax / Dbo≤1.550, and 0.450≤(Dcmax-Dbo) / (Dcmax-D 1pmax)≤1.000, it will be beneficial to maintain better adhesion when there is a large clearance gap G, and it will not be easily deformed, worn, or detached by external forces. At the same time, closing the clearance gap G will block stray light. In a preferred embodiment, the optical imaging lenses 100, 100A, and 100B satisfy the conditions 0.480≤(Dcmax-Dbo) / (Dcmax-Dci)≤0.900, 1.230≤Dcmax / Dbo≤1.510, and 0.450≤(Dcmax-Dbo) / (Dcmax-D 1pmax)≤0.800, but the present invention is not limited thereto.

[0067] In addition, in the above embodiments, when the optical imaging lenses 100, 100A, and 100B satisfy the following condition: Dco / Dbmax ≤ 0.320, the thin metal cap 110 is beneficial for minimizing the radial volume of the front end when the overall volume of the plastic lens barrel 120 is large. In a preferred embodiment, the optical imaging lenses 100, 100A, and 100B satisfy the condition 0.300 ≤ Dco / Dbmax ≤ 0.320, but the present invention is not limited thereto.

[0068] In addition, in the above embodiments, when the optical imaging lenses 100, 100A, and 100B satisfy the following condition: Dcmax / Dco ≥ 1.600, the reduction of the outermost object-side diameter of the metal cap 110 is beneficial to reducing the head volume of the optical imaging lenses 100, 100A, and 100B, while the image-side diameter of the metal cap 110 being as close as possible to the object-side diameter of the plastic lens barrel 120 is beneficial to increasing the contact surface with the plastic lens barrel 120 and thus increasing the adhesion strength. In a preferred embodiment, the optical imaging lenses 100, 100A, and 100B satisfy the condition 1.630 ≥ Dcmax / Dco ≥ 1.700, but the present invention is not limited thereto.

[0069] In addition, in the above embodiments, when the optical imaging lenses 100, 100A, and 100B satisfy the following condition: 0°≤α≤10°, it will be beneficial to adapt to the design of various lenses paired with the plastic lens barrel 120 to achieve the goal of ultra-small head.

[0070] In addition, in the above embodiments, when the optical imaging lenses 100, 100A, and 100B satisfy the following condition: 0.024mm≤Tm≤0.030mm, it will be beneficial to reduce the head volume of the optical imaging lenses 100, 100A, and 100B.

[0071] In addition, in the above embodiments, when the optical imaging lenses 100, 100A, and 100B satisfy the following condition: 0.000mm ≤ Pc ≤ 0.005mm, it will be beneficial to improve the assembly accuracy. In a preferred embodiment, the optical imaging lenses 100, 100A, and 100B satisfy the condition 0.000mm ≤ Pc ≤ 0.003mm, but the present invention is not limited thereto.

[0072] In addition, in the above embodiments, when the optical imaging lenses 100, 100A, and 100B satisfy the following condition: 50°≤β≤60°, it will be beneficial to reflect stray light and reduce stray light entering the optically effective area.

[0073] In summary, in the optical imaging lens of the present invention, for miniaturization purposes, the optical imaging lens includes a metal cap, a plastic lens barrel, and a plurality of lenses disposed within the plastic lens barrel along an optical axis from the object side to the image side. The plastic lens barrel includes a fixed surface facing the object side and a light-transmitting portion near the object side. The lens closest to the object side is a first lens, and the object-side surface of the first lens is located between the object side and the fixed surface. Specifically, the object-side portion of the relatively large plastic lens barrel is recessed, exposing the first lens. A clearance gap exists between the light-transmitting portion and the first lens. The metal cap is disposed on the fixed surface and forms a light-transmitting aperture. Therefore, by using the metal cap to block unwanted light from entering the clearance gap and protecting the exposed portion of the first lens, the reliability problem of the surface coating is overcome. Furthermore, the optical imaging lens satisfies the following conditions: 0.400≤(Dcmax-Dbo) / (Dcmax-D 1min)≤1.000 and 1.000≤Dco / D1min≤1.100, where Dcmax is the maximum outer diameter of the metal cap, Dbo is the inner diameter of the light-transmitting part closest to the object side, D 1min is the minimum outer diameter of the first lens closest to the object side, and Dco is the outer diameter of the metal cap closest to the object side. Therefore, when considering the fixing strength between the cap and the lens barrel and the clearance relationship between the light-transmitting part of the lens barrel and the lens, meeting the condition 0.400≤(Dcmax-Dbo) / (Dcmax-D 1min)≤1.000 allows for better adhesion even with a larger clearance, increasing the structural strength of the light-transmitting part. It is less susceptible to deformation, wear, or detachment due to external forces, while simultaneously sealing the clearance to block stray light. Furthermore, when the metal cap on the fixed surface satisfies 1.000≤Dco / D1min≤1.100 relative to the outer diameter of the lens protrusion, the radial volume of the head can be effectively reduced. The material strength and ductility of metal are beneficial for the manufacture of thin components, facilitating fine-tuning of the shape while ensuring reliability. For example, directly forming the aperture can reduce the assembly of additional micro-components, improve assembly ease, reduce the accumulation of assembly tolerances, meet coaxiality requirements, and increase lens reliability.

[0074] 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 a metal cap, a plastic lens barrel, and a plurality of lenses disposed within the plastic lens barrel along an optical axis from an object side to an image side, wherein, The plastic lens barrel includes a fixed surface facing the object and a light-transmitting portion near the object. The lens closest to the object side is a first lens, and one object side of the first lens is located between the object side and the fixed surface; The metal cap is disposed on the fixed surface and forms a light-transmitting aperture; There is a clearance gap between the light-transmitting part and the first lens; The optical imaging lens satisfies the following conditions: 0.400≤(Dcmax-Dbo) / (Dcmax-D 1min)≤1.000 and 1.000≤Dco / D 1min≤1.100, where Dcmax is the maximum outer diameter of the metal cap, Dbo is the inner diameter of the light-transmitting part closest to the object side, D 1min is the minimum outer diameter of the first lens closest to the object side, and Dco is the outer diameter of the metal cap closest to the object side.

2. The optical imaging lens as claimed in claim 1, wherein the optical imaging lens satisfies the following condition: 0.450≤(Dcmax-Dbo) / (Dcmax-Dci)≤1.000, where Dci is the outer diameter of one side wall of the metal cap closest to the image side.

3. The optical imaging lens as claimed in claim 1, wherein the optical imaging lens satisfies the following condition: 1.200≤Dcmax / Dbo≤1.

550.

4. The optical imaging lens as claimed in claim 1, wherein the optical imaging lens satisfies the following condition: 0.450≤(Dcmax-Dbo) / (Dcmax-D1pmax)≤1.000, where D1pmax is the maximum outer diameter of the first lens in the extension direction of the fixed surface.

5. The optical imaging lens as claimed in claim 1, wherein the optical imaging lens satisfies the following condition: Dco / Dbmax≤0.320, where Dbmax is the maximum outer diameter of the plastic lens barrel.

6. The optical imaging lens as claimed in claim 1, wherein the optical imaging lens satisfies the following condition: Dcmax / Dco ≥ 1.

600.

7. The optical imaging lens as claimed in claim 1, wherein the optical imaging lens satisfies the following condition: 0°≤α≤10°, where α is the angle between an outer surface of one side wall of the metal cap and the optical axis.

8. The optical imaging lens of claim 1, wherein the overall thickness of the metal cap is uniform.

9. The optical imaging lens as claimed in claim 1, wherein the optical imaging lens satisfies the following condition: 0.024mm≤Tm≤0.030mm, where Tm is the thickness of the metal cap.

10. The optical imaging lens of claim 1, wherein the metal cap is made of stainless steel or phosphor bronze.

11. The optical imaging lens of claim 1, wherein the metal cap is attached to the plastic lens barrel with thermosetting adhesive.

12. The optical imaging lens as claimed in claim 1, wherein the metal cap has a lens barrel connecting surface that contacts the fixed surface and an object-side plane that is parallel to the lens barrel connecting surface, and the optical imaging lens satisfies the following condition: 0.000mm≤Pc≤0.005mm, where Pc is the parallelism between the lens barrel connecting surface and the object-side plane.

13. The optical imaging lens of claim 1, wherein the surface of the metal cap is black.

14. The optical imaging lens of claim 1, wherein the surface of the first lens connecting the clearance gap has a blackened structure.

15. The optical imaging lens of claim 1, wherein the metal cap has a tapered surface at the edge adjacent to the light-transmitting aperture, tapering from the object side to the image side to the light-transmitting aperture, and the optical imaging lens satisfies the following condition: 50°≤β≤60°, where β is the angle between the tapered surface extending to the optical axis and the optical axis.

16. The optical imaging lens of claim 1, wherein the metal cap has a tapered surface at the edge adjacent to the light-transmitting aperture, the tapered surface being an arc surface.

Images