Lens barrel, telecentric lens and camera module

Abstract

The embodiment of the invention relates to the technical field of telecentric lenses, and provides a lens barrel, a telecentric lens and a camera module, the lens barrel of the telecentric lens comprises a first lens barrel, a second lens barrel and a third lens barrel which are arranged from an object side to an image side; the first lens barrel comprises a first channel and a second channel which are arranged from the object side to the image side, the axis of the second channel is perpendicular to the axis of the first channel, and the second channel and the first channel are communicated at the intersection point to form an L-shaped connection structure; the second lens cone is connected with a first switching assembly and a coaxial light source, and the coaxial light source is used for providing a light source for the interior of the second lens cone; one end of the second lens cone is connected with the second channel of the first lens cone, the other end of the second lens cone is rotatably connected with the third lens cone through a first switching assembly, the axis of the first channel is perpendicular to the axis of the second lens cone, and the axis of the second channel, the axis of the second lens cone and the axis of the third lens cone are parallel in pairs; the second lens cone is connected with a coaxial light source, and the optical axis of the coaxial light source is perpendicular to the axis of the second lens cone.

Description

Technical Field

[0001] This application relates to the technical field of telecentric lenses, and particularly to a lens barrel, a telecentric lens, and a camera module. Background Art

[0002] Machine vision inspection technology is widely applied to various links of manufacturing industries. In the appearance defect inspection links of many industries, machine vision inspection technology plays an important role, such as in the fields of circuit boards, semiconductor chips, display panels, food packaging, etc. With the continuous improvement of the level of industrial intelligence, the accuracy requirements for product defect inspection are getting higher and higher. Generally, a telecentric lens can be used to perform high-precision dimensional measurement or inspection on products.

[0003] The lens barrel of the telecentric lens in the related technology is a straight barrel type, that is, the object plane of the lens is parallel to the image plane. When installing the telecentric lens, sufficient length of space needs to be reserved and it cannot be arranged in a corner space. At the same time, in order to improve the imaging effect, a coaxial light source is usually added. In this way, while improving the imaging quality of the telecentric lens, not only does the overall volume of the telecentric lens with a coaxial light source increase, resulting in higher requirements for the placement space, but also the coaxial light source is relatively fixed relative to the lens barrel of the telecentric lens, and the installation is limited. Summary of the Invention

[0004] Embodiments of this application provide a lens barrel, a telecentric lens, and a camera module, which are used to solve the problem that the telecentric lens in the related technology has relatively high dimensional requirements for the layout space in the length direction and the application scenarios are limited.

[0005] To achieve the above object, the embodiments of this application adopt the following technical solutions:

[0006] In a first aspect, an embodiment of this application provides a lens barrel of a telecentric lens. The lens barrel includes a first lens barrel, a second lens barrel, and a third lens barrel arranged from the object side to the image side; the first lens barrel includes a first channel and a second channel arranged from the object side to the image side. The axis of the second channel is perpendicular to the axis of the first channel and is connected in an L-shaped connection structure at the intersection; a first adapter assembly and a coaxial light source are connected to the second lens barrel. The coaxial light source is used to provide light to the inside of the second lens barrel; one end of the second lens barrel is connected to the second channel of the first lens barrel, and the other end of the second lens barrel is rotatably connected to the third lens barrel through the first adapter assembly. The axis of the first channel is perpendicular to the axis of the second lens barrel, and the axes of the second channel, the second lens barrel, and the third lens barrel are parallel to each other in pairs; a coaxial light source is connected to the second lens barrel, and the optical axis of the coaxial light source is perpendicular to the axis of the second lens barrel.

[0007] In some embodiments, a second adapter assembly is connected to an end of the second lens barrel away from the first adapter assembly, and the first lens barrel and the second lens barrel are rotatably connected through the second adapter assembly.

[0008] In some embodiments, the first adapter assembly includes a first connecting cylinder, a second connecting cylinder, and a first fastener. The first connecting cylinder is screwed to the third lens barrel, the second connecting cylinder is screwed to the second lens barrel, the first connecting cylinder and the second connecting cylinder are snap-connected, and the first fastener is used to prevent the second lens barrel and the third lens barrel from rotating relative to each other.

[0009] In some embodiments, the first connecting cylinder includes a first cylinder section, a second cylinder section, and a third cylinder section arranged from the object side to the image side. The third cylinder section is connected to the third lens barrel. The inner diameter of the first cylinder section is smaller than the inner diameter of the second cylinder section, and the inner diameter of the third cylinder section is smaller than the inner diameter of the second cylinder section. The second connecting cylinder includes a first cylinder body and a second cylinder body arranged from the object side to the image side. The first cylinder body is connected to the second lens barrel. The outer diameter of the second cylinder body is larger than the outer diameter of the first cylinder body, the outer diameter of the second cylinder body is larger than the inner diameter of the second cylinder section, and the outer diameter of the first cylinder body is smaller than the inner diameter of the second cylinder section.

[0010] In some embodiments, an end of the second lens barrel near the image side has a first avoidance section. The outer diameter of the first avoidance section is smaller than the inner diameter of the first cylinder section. The first avoidance section is provided with an avoidance groove that extends along the circumferential direction of the first connecting cylinder. A through hole is provided on the first cylinder section. The through hole penetrates the first cylinder section along the radial direction of the first connecting cylinder. The first fastener is screwed to the through hole and can pass through the through hole and abut against the groove wall of the avoidance groove.

[0011] In some embodiments, in the axial direction of the second lens barrel, the length of the first avoidance section is less than or equal to the length of the first cylinder section.

[0012] In some embodiments, the groove side wall of the avoidance groove near the third lens barrel is inclined relative to the axis of the second lens barrel.

[0013] In some embodiments, a second adapter assembly is connected to an end of the second lens barrel away from the first adapter assembly, and the first lens barrel and the second lens barrel are rotatably connected through the second adapter assembly. The second adapter assembly includes a third connecting cylinder, a fourth connecting cylinder, and a second fastener. The third connecting cylinder is screwed to the first lens barrel, the fourth connecting cylinder is screwed to the second lens barrel, the third connecting cylinder and the fourth connecting cylinder are snap-connected, and the second fastener is used to prevent the first lens barrel and the second lens barrel from rotating relative to each other.

[0014] In some embodiments, the second lens barrel includes a second avoidance section, a main section and the first avoidance section arranged from the object side to the image side, the second avoidance section is connected to the first lens barrel through the second adapter assembly, a light source mounting hole is provided on the side wall of the main section, the light source mounting hole is connected to the coaxial light source, the light source mounting hole passes through a side wall of the main section along the radial direction of the second lens barrel, and the structure of the second avoidance section is symmetrical with that of the first avoidance section about the axis of the light source mounting hole.

[0015] In some embodiments, the optical axis of the coaxial light source is perpendicular to the axis of the second lens barrel, a 45° beam splitter prism is provided inside the second lens barrel, and the light emitted by the coaxial light source enters the interior of the second lens barrel through the 45° beam splitter prism.

[0016] The lens barrel of the telecentric lens provided in the embodiment of the present application includes a first lens barrel, a second lens barrel and a third lens barrel along the object side to the image side, that is, the lens barrel as a whole adopts a multi-section structure, the first lens barrel includes a first channel and a second channel whose axes are perpendicular to each other, and the first channel and the second channel are connected to form an L-shaped connection structure, so that when optical elements such as a first lens group and a reflector are arranged in the first lens barrel, the optical axis of the light entering from the first channel can be deflected by 90° and then emitted from the second channel, and at the same time, the axis of the second channel, the axis of the second lens barrel and the axis of the third lens barrel are parallel to each other, and the structure of the lens barrel is relative to the structure of a straight-tube lens barrel, which reduces the axial direction of the third lens barrel. The length on is adapted to the placement in the corner space. When the lens group is arranged with the lens group, the object plane and the image plane are perpendicular to each other. Secondly, the second lens barrel and the second lens barrel are rotatably connected through the first adapter assembly. That is to say, a rotating pair is formed between the second lens barrel and the third lens barrel, which can realize 360° rotation around the axis parallel to the second lens barrel. Then, a coaxial light source is connected to the second lens barrel, so that when the second lens barrel and the second lens barrel rotate relative to each other, the relative position of the image plane and the coaxial light source can be changed, so that the telecentric lens can realize the relative position adjustment between the coaxial light source and the image plane on the basis of the perpendicularity between the image plane and the object plane, thereby further reducing the restriction on the placement space of the telecentric lens.

[0017] In a second aspect, an embodiment of the present application provides a telecentric lens, comprising a lens barrel, a first lens group and a second lens group as described in the first aspect, wherein the first lens group is arranged inside the first lens barrel of the lens barrel, and the second lens group is arranged inside the third lens barrel of the lens barrel.

[0018] The structure and technical effects of the lens barrel in the telecentric lens in the embodiment of the present application are the same as those of the lens barrel in the telecentric lens in the first aspect, and are not described in detail here.

[0019] Thirdly, an embodiment of the present application provides a camera module, including a photosensitive element and the telecentric lens described in the first aspect, where the photosensitive element is disposed on the image side of the telecentric lens.

[0020] The structure and technical effects of the telecentric lens in the camera module in the embodiment of the present application are the same as those of the telecentric lens in the second aspect, and will not be described herein again. Description of the Drawings

[0021] Figure 1 is a schematic structural diagram of the telecentric lens in the embodiment of the present application;

[0022] Figure 2 is Figure 1 a sectional view of;

[0023] Figure 3 is Figure 2 an enlarged view of part I of;

[0024] Figure 4 is a partial exploded view of the second lens barrel, the first adapter assembly and the third lens barrel;

[0025] Figure 5 is a partial exploded view of the first lens barrel, the second adapter assembly and the second lens barrel.

[0026] Among them, the reference numerals in the drawings are as follows:

[0027] 1. First lens barrel; 101. First channel; 102. Second channel; 11. First section; 12. Second section; 13. Adapter tube; 14. Reflecting mirror;

[0028] 2. Second lens barrel; 201. Avoidance groove; 21. First avoidance section; 22. Second avoidance section; 23. Main body section; 230. Light source mounting hole;

[0029] 3. Third lens barrel;

[0030] 4. First adapter assembly; 41. First connecting tube; 410. Through hole; 411. First tube section; 412. Second tube section; 413. Third tube section; 42. Second connecting tube; 421. First cylinder body; 422. Second cylinder body; 43. First fastener;

[0031] 5. Second adapter assembly; 51. Third connecting tube; 52. Fourth connecting tube; 53. Second fastener;

[0032] 6. Coaxial light source;

[0033] 7. Photosensitive element;

[0034] The first lens group G1; the second lens group G2; the first lens L1; the second lens L2; the third lens L3; the fourth lens L4; the fifth lens L5; the sixth lens L6; the 45° beam splitting prism L7. Detailed implementation manners

[0035] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0036] In the embodiments of the present application, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, unless otherwise specified, the meaning of "a plurality" is two or more.

[0037] As Figure 1 、 Figure 2 shown, the embodiments of the present application provide a camera module, including a telecentric lens and a photosensitive element 7, and the photosensitive element 7 is located on the image side of the telecentric lens.

[0038] The working principle of the camera module is as follows: The light reflected by the object to be photographed passes through the telecentric lens to generate an optical image and projects it onto the photosensitive surface of the photosensitive element 7. The photosensitive element 7 converts the optical image into an electrical signal, that is, an analog image signal, and transmits it to the processor.

[0039] Among them, the photosensitive element 7 (also known as an image sensor) is a semiconductor chip, and its surface contains hundreds of thousands to millions of photodiodes. When irradiated by light, it will generate charges. The photosensitive element 7 can be a charge-coupled device (CCD) or a complementary metal-oxide semiconductor device (CMOS). The CCD is made of a high-sensitivity semiconductor material and can convert light into charges. The charge-coupled device consists of many photosensitive units, usually in units of millions of pixels. When the surface of the photosensitive element 7 is irradiated by light, each photosensitive unit will reflect the charges on the component, and the signals generated by all the photosensitive units are added together to form a complete picture.

[0040] Among them, the telecentric lens is an optical lens mainly used in the fields of machine vision, precision measurement, and detection. The optical lens mainly uses the refraction principle of the lens to form an image, that is, the scene light passes through the optical lens, forms a clear image on the focal plane, and the image of the scene is recorded by the photosensitive element 7 located on the focal plane.

[0041] As Figure 2 and Figure 3 shown, the telecentric lens includes a lens barrel, a first lens group, and a second lens group.

[0042] The above-mentioned first lens group G1 and second lens group G2 form the imaging system of the telecentric lens. Hereinafter, the imaging system including the first lens group G1 and the second lens group G2 will be taken as an example for description. As Figure 2 and shown, the first lens group G1 includes a first lens L1, a second lens L2, a third lens L3, and a fourth lens L1 arranged from the object side to the image side; the second lens group G2 includes a fifth lens L5 and a sixth lens L6 arranged from the object side to the image side.

[0043] As Figure 2 and Figure 3 shown, the lens barrel includes a first lens barrel 1, a second lens barrel 2, and a third lens barrel 3 arranged from the object side to the image side; the first lens barrel 1 includes a first channel 101 and a second channel 102 arranged from the object side to the image side. The axis of the second channel 102 is perpendicular to the axis of the first channel 101 and communicates at the intersection to form an L-shaped connection structure, that is, the first channel 101 and the second channel 102 communicate to form an L-shaped connection structure; a first adapter assembly 4 and a coaxial light source 6 are connected to the second lens barrel 2. The coaxial light source 6 is used to provide light source to the inside of the second lens barrel 2; one end of the second lens barrel 2 is connected to the second channel 102 of the first lens barrel 1, and the other end of the second lens barrel 2 is rotatably connected to the third lens barrel 3 through the first adapter assembly 4. The axis of the first channel 101 is perpendicular to the axis of the second lens barrel 2, and the axes of the second channel 102, the second lens barrel 2, and the third lens barrel 3 are parallel to each other in pairs; a coaxial light source 6 is connected to the second lens barrel 2, and the optical axis of the coaxial light source 6 is perpendicular to the axis of the second lens barrel 2.

[0044] As Figure 2As shown, the above-mentioned first lens barrel 1 includes a first section 11, a second section 12, and an adapter barrel 13. The first section 11 and the second section 12 are connected by the adapter barrel 13. The adapter barrel 13 has two interfaces arranged opposite to each other. One interface is connected to the first section 11 to form a first channel 101, and the other interface is connected to the second section 12 to form a second channel 102. A reflecting mirror 14 is provided inside the adapter barrel 13. The reflecting mirror 14 has a reflecting surface, and the center of the above-mentioned reflecting surface refers to the geometric center of the reflecting surface. The axis of the first channel 101 is perpendicularly intersecting with the axis of the second channel, and the intersection is in an L-shaped connection structure. The reflecting mirror 14 is arranged at the corner for deflecting the optical axis of the first lens group G1 by 90° so as to be parallel to the optical axis of the second lens group G2.

[0045] The other end of the above-mentioned second lens barrel 2 ( Figure 2 the right end in the figure) is rotatably connected to the third lens barrel 3 through a first adapter assembly 4, which means that the axis of the second lens barrel 2 is parallel to the axis of the third lens barrel 3, and the second lens barrel 2 and the third lens barrel 3 can rotate relative to each other around the axis of the third lens barrel 3. Usually, the third lens barrel 3 is connected to the photosensitive element 7, so the third lens barrel 3 is fixed. When installing the second lens barrel 2, the second lens barrel 2 can rotate relative to the axis of the third lens barrel 3. At the same time, it drives the coaxial light source 6 to rotate, that is, the coaxial light source 6 can rotate 360° relative to the third lens barrel 3 around the axis of the third lens barrel 3 to adjust the relative position angle between the coaxial light source 6 and the image plane of the photosensitive element 7.

[0046] The optical axis of the above-mentioned coaxial light source 6 is perpendicular to the axis of the second lens barrel 2, and the axis of the first channel 101 is perpendicular to the axis of the second lens barrel 2. Therefore, when the coaxial light source 6 rotates until the optical axis of the coaxial light source 6 is parallel to the axis of the first channel 101, the volume of the placement space of the lens barrel of the telecentric lens barrel is minimized. Of course, when the placement space of the telecentric lens is relatively sufficient, the axis of the coaxial light source 6 can also be a skew line with the axis of the first channel 101.

[0047] The lens barrel of the telecentric lens provided in the embodiment of the present application includes a first lens barrel 1, a second lens barrel 2 and a third lens barrel 3 along the object side to the image side. That is to say, the lens barrel as a whole adopts a multi-section structure. The first lens barrel 1 includes a first channel 101 and a second channel 102 whose axes are perpendicular to each other. The first channel 101 and the second channel 102 are connected to form an L-shaped connection structure. In this way, when optical elements such as a first lens group and a reflector are arranged in the first lens barrel 1, the optical axis of the light entering from the first channel 101 can be deflected by 90° and then emitted from the second channel 102. At the same time, the axis of the second channel 102, the axis of the second lens barrel 2 and the axis of the third lens barrel 3 are parallel to each other. Compared with the structure of a straight-tube lens barrel, the structure of the lens barrel reduces the time required for the third lens barrel to be used. The length of the lens barrel 3 in the axial direction is adapted to the placement in the angular space. When the lens groups are arranged, the object plane and the image plane are perpendicular to each other. Secondly, the second lens barrel 2 and the second lens barrel 2 are rotatably connected via the first adapter assembly 4. That is to say, a rotating pair is formed between the second lens barrel 2 and the third lens barrel 3, which can realize 360° rotation around an axis parallel to the second lens barrel 2. Then, a coaxial light source 6 is connected to the second lens barrel 2, so that when the second lens barrel 2 and the second lens barrel 2 rotate relative to each other, the relative position of the image plane and the coaxial light source 6 can be changed, so that the telecentric lens can realize the relative position adjustment between the coaxial light source 6 and the image plane on the basis of the perpendicularity between the image plane and the object plane, thereby further reducing the restriction on the placement space of the telecentric lens.

[0048] like Figure 2 , Figure 3 and Figure 4 As shown, in some embodiments, the second lens barrel 2 includes a second avoidance section 22, a main section 23 and a first avoidance section 21 arranged from the object side to the image side, the first avoidance section 21 is connected to the third lens barrel 3 through a first adapter component 4, the second avoidance section 22 is connected to the first lens barrel 1 through a second adapter component 5, a light source mounting hole 230 is opened on the side wall of the main section 23, a coaxial light source 6 is connected to the light source mounting hole 230, and the light source mounting hole 230 is arranged along the radial direction of the second lens barrel 2 ( Figure 3 The second avoidance section 22 and the first avoidance section 21 are axially symmetrical about the axis of the light source mounting hole 230.

[0049] The first avoidance section 21 and the second avoidance section 22 have a smaller outer diameter than the main section 23, so that installation space is reserved at both ends of the second lens barrel 2 for connection with the first adapter assembly 4 and the second adapter assembly 5, so that the various components of the lens barrel can reasonably utilize the space of the second lens barrel 2 on the basis of firm connection, which is conducive to miniaturization of the lens barrel volume. The main section 23 refers to a section connected to the coaxial light source 6. The outer diameter of the main section 23 is relatively large, which is conducive to improving the firmness of the connection between the main section 23 and the coaxial light source 6, thereby helping to improve the reliability of the entire lens barrel.

[0050] Through the above settings, the structure of the second lens barrel 2 is axisymmetric, simplifying the structure and processing procedures of the second lens barrel 2, while reducing the processing cost. In addition, it is convenient to assemble and connect with the first lens barrel 1 and the second lens barrel 2.

[0051] It should be noted that the structure of the second avoidance section 22 and the structure of the first avoidance section 21 can be axisymmetric about the axis of the light source mounting hole 230. In addition, the structure of the second avoidance section 22 can also be different from the structure of the first avoidance section 21. However, the difference here only includes the difference in size. For example, the sizes of the second avoidance section 22 and the first avoidance section 21 may not be exactly the same. At this time, the structure of the first adapter assembly 4 needs to be adjusted according to the sizes of the second avoidance section 22 and the first avoidance section 21, but the outline and function of the structure remain unchanged.

[0052] As Figure 3 and Figure 4 shown, one end of the second lens barrel 2 is rotatably connected to the third lens barrel 3 through the first adapter assembly 4. The other end of the second lens barrel 2 away from the first adapter assembly 4 is connected with a second adapter assembly 5. The first lens barrel 1 and the second lens barrel 2 are rotatably connected through the second adapter assembly 5.

[0053] The above-mentioned first lens barrel 1 and the second lens barrel 2 are rotatably connected through the second adapter assembly 5. That is to say, a revolute pair is formed between the second lens barrel 2 and the first lens barrel 1, and it can rotate 360° around an axis parallel to the axis of the second lens barrel 2.

[0054] Through the above settings, not only can the first lens barrel 1 of the lens barrel of the telecentric lens also rotate relative to the axis of the third lens barrel 3, that is, on the basis that the object plane of the imaging system of the telecentric lens is perpendicular to the image plane, the relative position angle between the object plane and the image plane can be adjusted to meet the requirements of different placement spaces.

[0055] As Figure 3 and Figure 4 shown, the first adapter assembly 4 includes a first connecting cylinder 41, a second connecting cylinder 42 and a first fastener 43. The first connecting cylinder 41 is screwed to the third lens barrel 3, the second connecting cylinder 42 is screwed to the second lens barrel 2, the first connecting cylinder 41 is clamped to the second connecting cylinder 42, and the first fastener 43 is used to prevent the second lens barrel 2 and the third lens barrel 3 from rotating relative to each other.

[0056] With the above settings, after the first connecting cylinder 41 and the second connecting cylinder 42 are snap-connected and then screwed and fixed to the second lens barrel 2 and the third lens barrel 3 correspondingly, not only can the second connecting cylinder 42 drive the second lens barrel 2 to rotate relative to the first connecting cylinder 41 around the axis of the third lens barrel 3, so that the second lens barrel 2 and the third lens barrel 3 rotate relative to each other, but also, when their relative positions are fixed, the second lens barrel 2, the third lens barrel 3, the first connecting cylinder 41 and the second connecting cylinder 42 can be fixed relative to each other in pairs through the first fastener 43.

[0057] As Figure 3 and Figure 4 shown, the first connecting cylinder 41 includes a first cylinder section 411, a second cylinder section 412 and a third cylinder section 413 arranged from the object side to the image side. The third cylinder section 413 is connected to the third lens barrel 3. The inner diameter of the first cylinder section 411 is smaller than that of the second cylinder section 412, and the inner diameter of the third cylinder section 413 is smaller than that of the second cylinder section 412. The second connecting cylinder 42 includes a first cylinder body 421 and a second cylinder body 422 arranged from the object side to the image side. The first cylinder body 421 is connected to the second lens barrel 2. The outer diameter of the second cylinder body 422 is larger than that of the first cylinder body 421, the outer diameter of the second cylinder body 422 is larger than the inner diameter of the second cylinder section 412, and the outer diameter of the first cylinder body 421 is smaller than the inner diameter of the second cylinder section 412.

[0058] With the above settings, the first connecting cylinder 41 and the second connecting cylinder 42 can be sleeved together. A notch is formed at the connection between the first cylinder body 421 and the second cylinder body 422, and the second cylinder section 412 is snap-connected to the notch. When there is a gap between the end face of the second cylinder section 412 and the end face of the second cylinder body 422, the first connecting cylinder 41 and the second connecting cylinder 42 can rotate relative to each other; at least one of the first connecting cylinder 41 and the second connecting cylinder 42 moves axially along the second lens barrel 2 until the end face of the second cylinder section 412 contacts the end face of the second cylinder body 422, and the first connecting cylinder 41 and the second connecting cylinder 42 can be fixed relative to each other and can only rotate relative to each other when the torque is greater than the frictional force.

[0059] As Figure 3 and Figure 4 shown, the outer diameter of the first avoidance section 21 is smaller than the inner diameter of the first cylinder section 411. The first avoidance section 21 is provided with an avoidance groove 201, and the avoidance groove 201 extends along the circumferential direction of the first connecting cylinder 41. A through hole 410 is provided on the first cylinder section 411. The through hole 410 penetrates the first cylinder section 411 along the radial direction of the first connecting cylinder 41. The first fastener 43 is screwed with the through hole 410 and can pass through the through hole 410 and abut against the groove wall of the avoidance groove 201.

[0060] With the above settings, after the first connecting cylinder 41 and the second connecting cylinder 42 are snap-fitted, and then correspondingly screwed and fixed to the second lens barrel 2 and the third lens barrel 3, the first connecting cylinder 41 and the second connecting cylinder 42 are snap-fitted, and there is a gap between the first connecting cylinder 41 and the second connecting cylinder 42 that allows relative rotation. That is, the second connecting cylinder 42 drives the second lens barrel 2 to be able to rotate relative to the first connecting cylinder 41 around the axis of the third lens barrel 3, so that the second lens barrel 2 and the third lens barrel 3 rotate relative to each other; when the first fastener 43 is screwed into the through hole 410 until it abuts against the groove wall of the avoidance groove 201, the relative rotation between the second lens barrel 2 and the third lens barrel 3 is restricted, making the second lens barrel 2, the third lens barrel 3, the first connecting cylinder 41 and the second connecting cylinder 42 fixed relative to each other in pairs.

[0061] As Figure 3 shown, in the axial direction of the second lens barrel 2, the length of the first avoidance section 21 is less than or equal to the length of the first barrel section 411.

[0062] With the above settings, during the screwing process of the first connecting cylinder 41 and the third lens barrel 3, the first connecting cylinder 41 and the second connecting cylinder 42 can be brought into full axial contact, increasing the friction force between the first connecting cylinder 41 and the second connecting cylinder 42, which is beneficial to firmly connecting the second lens barrel 2 and the third lens barrel 3.

[0063] As Figure 3 and Figure 4 shown, the groove side wall on the side of the avoidance groove 201 close to the third lens barrel 3 is inclined with respect to the axis of the second lens barrel 2.

[0064] With the above settings, during the screwing process of the first fastener 43 and the through hole 410, a force is applied to the groove side wall of the avoidance groove 201 to move the second lens barrel 2 axially towards the side close to the third lens barrel 3, making the first connecting cylinder 41 and the second connecting cylinder 42 in surface contact along the axial direction, so that the connection between the second lens barrel 2 and the third lens barrel 3 is firmer.

[0065] As Figure 3 、 Figure 4 and Figure 5 shown, the second adapter assembly 5 includes a third connecting cylinder 51, a fourth connecting cylinder 52 and a second fastener 53. The third connecting cylinder 51 is screwed to the first lens barrel 1, the fourth connecting cylinder 52 is screwed to the second lens barrel 2, the third connecting cylinder 51 and the fourth connecting cylinder 52 are snap-fitted, and the second fastener 53 is used to prevent the first lens barrel 1 and the second lens barrel 2 from rotating relative to each other.

[0066] An assembly process of the second lens barrel 2, the first adapter assembly 4 and the third lens barrel 3 is as follows:

[0067] First, the first connecting cylinder 41 and the second connecting cylinder 42 are snap-connected and then screwed and fixed to the third lens barrel 3. Then, the second connecting cylinder 42 is screwed and fixed to the second lens barrel 2. At this time, the first connecting cylinder 41 and the second connecting cylinder 42 are snap-connected and can rotate relative to each other around the axis of the third lens barrel 3, so that the second lens barrel 2 rotates relative to the third lens barrel 3;

[0068] Finally, the first fastener 43 is screwed into the through hole 410 until it abuts against the wall of the avoidance groove 201, so that the second lens barrel 2, the first adapter assembly 4, and the third lens barrel 3 are fixed to each other in pairs.

[0069] Another assembly process is as follows:

[0070] First, the first connecting cylinder 41 and the second connecting cylinder 42 are snap-connected and then screwed and fixed to the second lens barrel 2. Then, the first connecting cylinder 41 is screwed and fixed to the third lens barrel 3. At this time, the first connecting cylinder 41 and the second connecting cylinder 42 are snap-connected and can rotate relative to each other around the axis of the third lens barrel 3, so that the second lens barrel 2 rotates relative to the third lens barrel 3;

[0071] Finally, the first fastener 43 is screwed into the through hole 410 until it abuts against the wall of the avoidance groove 201, so that the second lens barrel 2, the first adapter assembly 4, and the third lens barrel 3 are fixed to each other in pairs.

[0072] The assembly process of the first lens barrel 1, the second lens barrel 2, and the second adapter assembly 5 is the same as that of the first adapter, the second lens barrel 2, and the third lens barrel 3, and also includes the above two assembly methods.

[0073] It should be noted that in addition to including the second avoidance section 22, the main body section 23, and the first avoidance section 21 arranged from the object side to the image side, in some other embodiments, the second lens barrel 2 may also only include the main body section 23 and the first avoidance section 21. That is to say, only one end of the second lens barrel 2 close to the image side has the first avoidance section 21, and the other end is integrally connected to the first lens barrel 1, which is not specifically limited here.

[0074] As Figure 2 and Figure 3 shown, the optical axis of the coaxial light source 6 ( Figure 3 in the vertical direction) is perpendicular to the axis of the second lens barrel 2. A 45° beam splitter prism L7 is provided inside the second lens barrel 2, and the light emitted by the coaxial light source 6 enters the inside of the second lens barrel 2 through the 45° beam splitter prism L7.

[0075] The above 45° beam splitter prism L7 serves to split the light emitted by the coaxial light source 6 into two beams through reflection and refraction, and the reflected light and the transmitted light are usually at a 90° angle.

[0076] Through the above settings, the optical axis of the coaxial light source 6 is parallel to the axis of the first channel 101, improving the space utilization rate and thus reducing the placement space of the telecentric lens.

[0077] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application and are not intended to limit them. Although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments or equivalently replace some of the technical features. These modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A telecentric lens barrel, characterized in that: include: A first lens barrel (1), a second lens barrel (2) and a third lens barrel (3) arranged from the object side to the image side; The first lens barrel (1) comprises a first channel (101) and a second channel (102) arranged from the object side to the image side, the axis of the second channel (102) being perpendicular to the axis of the first channel (101) and being connected at the intersection to form an L-shaped connection structure; The second lens barrel (2) is connected to a first adapter component (4) and a coaxial light source (6), and the coaxial light source (6) is used to provide light to the interior of the second lens barrel (2); one end of the second lens barrel (2) is connected to the second channel (102) of the first lens barrel (1), and the other end of the second lens barrel (2) is rotatably connected to the third lens barrel (3) through the first adapter component (4); the axis of the first channel (101) is perpendicular to the axis of the second lens barrel (2), and the axes of the second channel (102), the second lens barrel (2) and the third lens barrel (3) are parallel to each other.

2. The lens barrel according to claim 1, characterized in that: One end of the second lens barrel (2) away from the first adapter assembly (4) is connected to a second adapter assembly (5), and the first lens barrel (1) and the second lens barrel (2) are rotatably connected via the second adapter assembly (5).

3. The lens barrel according to claim 1, characterized in that: The first adapter assembly (4) comprises a first connecting tube (41), a second connecting tube (42) and a first fastener (43); the first connecting tube (41) is threadedly connected to the third lens barrel (3); the second connecting tube (42) is threadedly connected to the second lens barrel (2); the first connecting tube (41) and the second connecting tube (42) are snap-fitted; and the first fastener (43) is used to prevent the second lens barrel (2) and the third lens barrel (3) from rotating relative to each other.

4. The lens barrel according to claim 3, characterized in that: The first connecting tube (41) comprises a first tube section (411), a second tube section (412) and a third tube section (413) arranged from the object side to the image side, the third tube section (413) being connected to the third lens barrel (3), the inner diameter of the first tube section (411) being smaller than the inner diameter of the second tube section (412), and the inner diameter of the third tube section (413) being smaller than the inner diameter of the second tube section (412); The second connecting tube (42) comprises a first tube body (421) and a second tube body (422) arranged from the object side to the image side, the first tube body (421) is connected to the second lens barrel (2), the outer diameter of the second tube body (422) is greater than the outer diameter of the first tube body (421), the outer diameter of the second tube body (422) is greater than the inner diameter of the second tube section (412), and the outer diameter of the first tube body (421) is smaller than the inner diameter of the second tube section (412).

5. The lens barrel according to claim 4, characterized in that: The second lens barrel (2) has a first avoidance section (21) at one end close to the image side, the outer diameter of the first avoidance section (21) is smaller than the inner diameter of the first barrel section (411), the first avoidance section (21) is provided with an avoidance groove (201), and the avoidance groove (201) extends along the circumference of the first connecting barrel (41); The first barrel section (411) is provided with a through hole (410), and the through hole (410) penetrates the first barrel section (411) in a radial direction of the first connecting barrel (41), and the first fastener (43) is screwed to the through hole (410) and can pass through the through hole (410) to abut against the groove wall of the avoidance groove (201).

6. The lens barrel according to claim 5, characterized in that: In the axial direction of the second lens barrel (2), the length of the first avoidance section (21) is less than or equal to the length of the first barrel section (411).

7. The lens barrel according to claim 5, characterized in that: The groove side wall of the avoidance groove (201) on the side close to the third lens barrel (3) is arranged obliquely relative to the axis of the second lens barrel (2).

8. The lens barrel according to any one of claims 5 to 7, characterized in that: The end of the second lens barrel (2) away from the first adapter assembly (4) is connected to the second adapter assembly (5), and the first lens barrel (1) and the second lens barrel (2) are rotatably connected via the second adapter assembly (5); the end of the second lens barrel (2) away from the first adapter assembly (4) is connected to the second adapter assembly (5), and the first lens barrel (1) and the second lens barrel (2) are rotatably connected via the second adapter assembly (5); the second adapter assembly (5) comprises a third connecting tube (51), a fourth connecting tube (52) and a second fastener (53), the third connecting tube (51) is screwed to the first lens barrel (1), the fourth connecting tube (52) is screwed to the second lens barrel (2), the third connecting tube (51) is clamped to the fourth connecting tube (52), and the second fastener (53) is used to prevent the first lens barrel (1) and the second lens barrel (2) from rotating relative to each other.

9. The lens barrel according to claim 8, characterized in that: The second lens barrel (2) comprises a second avoidance section (22), a main section (23) and the first avoidance section (21) arranged from the object side to the image side; the second avoidance section (22) is connected to the first lens barrel (1) via the second adapter assembly (5); a light source mounting hole (230) is provided on a side wall of the main section (23); the light source mounting hole (230) is connected to the coaxial light source (6); the light source mounting hole (230) penetrates a side wall of the main section (23) in a radial direction of the second lens barrel (2); and the structure of the second avoidance section (22) and the structure of the first avoidance section (21) are symmetrical about the axis of the light source mounting hole (230).

10. The lens barrel according to any one of claims 1 to 7, characterized in that: The optical axis of the coaxial light source (6) is perpendicular to the axis of the second lens barrel (2); a 45° beam splitter prism is provided inside the second lens barrel (2); and light emitted by the coaxial light source (6) enters the interior of the second lens barrel (2) through the 45° beam splitter prism.

11. A telecentric lens, characterized in that: include: The lens barrel according to any one of claims 1 to 10; A first lens group is disposed inside a first lens barrel of the lens barrel; The second lens group is arranged inside the third lens barrel of the lens barrel.

12. A camera module, characterized in that: include: The telecentric lens as claimed in claim 11; A photosensitive element (7), wherein the photosensitive element (7) is arranged on the image side of the telecentric lens.

Images