Lens device for multi-angle inner wall detection and optical system thereof

Abstract

The invention relates to the technical field of optical imaging, and discloses a multi-angle inner wall detection lens device and an optical system thereof. The optical system comprises a reflection assembly T1 and an imaging lens group T2 which are sequentially arranged from an object side to an image side; the reflecting assembly T1 comprises a first reflecting mirror group M1 and a second reflecting mirror group M2; the optical axis included angle between the incident light of the reflecting assembly T1 and the imaging lens group T2 is alpha, the optical axis included angle between the first reflecting mirror group M1 and the imaging lens group T2 is beta 1, the optical axis included angle between the second reflecting mirror group M2 and the imaging lens group is beta 2, and alpha, beta 1 and beta 2 meet the relational expressions that alpha is larger than or equal to 10 degrees and smaller than or equal to 60 degrees, beta 2 is larger than or equal to 15 degrees and smaller than or equal to 40 degrees, and alpha = 2 * beta 2-2 * beta 1. Through the structural design of the optical system, multi-angle optical imaging of the inner wall of a cylindrical product or a cavity workpiece is achieved, images of six angles can be obtained through single shooting, the situation of the whole inner wall is completely presented, and space and cost are greatly saved.

Description

Technical Field

[0001] The present invention relates to the technical field of optical imaging, and particularly to a lens device for multi-angle inner wall detection and its optical system. Background Art

[0002] With the rapid development of the microelectronics industry, machine vision systems with high resolution and high processing speed are constantly emerging. Among them, the application of inner wall detection of cylindrical products or cavity workpieces is increasing day by day. Inner wall detection generally requires accurate identification of internal defects, such as cracks, scratches, dirt, etc. Specifically designed high-resolution imaging is the key to improving detection accuracy, which poses new requirements for optical lenses. Conventional machine vision lenses can only image flat surfaces. To obtain complete information on the inner wall of a cylindrical product or cavity workpiece, the lens needs to be tilted to align with one side of the inner wall to collect images, and then the workpiece is rotated to photograph the other side. This detection method is time-consuming, the detection assembly is complex, and the inner wall detection is incomplete.

[0003] In order to reduce the shooting space and cost, there is an urgent need for a machine vision lens that can photograph the bottom of the inner hole of an object and the vertical inner wall from multiple perspectives.

[0004] The above information is given as background information only to assist in understanding the present disclosure, and does not determine or admit whether any of the above content can be used as prior art relative to the present disclosure. Summary of the Invention

[0005] The purpose of the present invention is to provide a lens device for multi-angle inner wall detection and its optical system to solve or at least partially solve the technical problems existing in the prior art.

[0006] To achieve this purpose, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides an optical system of a lens device for multi-angle inner wall detection, including a reflection component T1 and an imaging lens group T2 arranged in sequence from the object side to the image side;

[0008] The reflection component T1 includes a first mirror group M1 and a second mirror group M2, and an annular light illumination source S0 is also provided between the first mirror group M1 and the second mirror group M2;

[0009] The included angle between the incident light of the reflection component T1 and the optical axis of the imaging lens group T2 is α, the included angle between the first mirror group M1 and the optical axis of the imaging lens group T2 is β1, and the included angle between the second mirror group M2 and the optical axis of the imaging lens group T2 is β2. α, β1, and β2 satisfy the following relational expressions:

[0010] 10° ≤ α ≤ 60°, 15° ≤ β2 ≤ 40°, α = 2 * β2 - 2 * β1.

[0011] Optionally, the imaging lens group T2 includes a front group L1 with positive refractive power, a diaphragm A0, and a rear group L2 with positive refractive power, which are arranged in sequence from the object side to the image side;

[0012] The front group L1 includes a first lens G1 with positive refractive power, a second lens G2 with positive refractive power, and a third lens G3 with negative refractive power, which are arranged in sequence from the object side to the image side. Among them, the second lens G2 and the third lens G3 are cemented into a first cemented lens group U1 with positive refractive power;

[0013] The rear group L2 includes a fourth lens G4 with negative refractive power, a fifth lens G5 with positive refractive power, and a sixth lens G6 with positive refractive power. Among them, the fourth lens G4 and the fifth lens G5 are cemented into a second cemented lens group U2 with negative refractive power.

[0014] Optionally, the focal length of the first lens G1 is f G1 , and the focal length of the front group L1 is f L1 , f G1 and f L1 satisfy the relational expression: 1.20 < |f G1 / f L1 | < 1.90;

[0015] The focal length of the sixth lens G6 is f G6 , and the focal length of the rear group L2 is f L2 , f G6 and f L2 satisfy the relational expression: 0.70 < |f G6 / f L2 | < 1.25.

[0016] Optionally, the Abbe number of the second lens G2 is V2, and the Abbe number of the third lens G3 is V3. V2 and V3 satisfy the relational expression: 10 < |V2 - V3| < 45;

[0017] The Abbe number of the fourth lens G4 is V4, and the Abbe number of the fifth lens G5 is V5. V4 and V5 satisfy the relational expression: 25 < |V4 - V5| < 55.

[0018] Optionally, the first lens G1, the second lens G2, the fifth lens G5, and the sixth lens G6 are all biconvex lenses, and the third lens G3 and the fourth lens G4 are both biconcave lenses.

[0019] Optionally, the first lens G1, the second lens G2, the third lens G3, the fourth lens G4, the fifth lens G6, and the sixth lens G6 are all spherical glass lenses.

[0020] Optionally, the first lens G1 is made of heavy phosphate crown glass, the second lens G2 is made of fluor crown glass, the third lens G3 is made of lanthanum flint glass, the fourth lens G4 is made of heavy flint glass, the fifth lens G6 is made of heavy phosphate crown glass, and the sixth lens G6 is made of heavy lanthanum flint glass.

[0021] Optionally, the first mirror group M1 includes six rectangular first plane mirrors evenly distributed around the optical axis; the second mirror group M2 includes six isosceles trapezoidal second plane mirrors evenly distributed around the optical axis and respectively used in one-to-one cooperation with the six first plane mirrors;

[0022] The side of the second plane mirror away from the first lens G1 is the narrower base of the isosceles trapezoid, and the narrower base is arranged close to the optical axis of the imaging lens group T2.

[0023] Optionally, the optical axes of the first lens G1, the second lens G2, the third lens G3, the fourth lens G4, the fifth lens G6, and the sixth lens G6 all coincide with the optical axis of the imaging lens group T2;

[0024] The aperture of the diaphragm A0 is a circular hole, and the center of the circular hole is on the optical axis of the imaging lens group T2.

[0025] In a second aspect, the present invention provides a lens device for multi-angle inner wall detection, including the optical system of a lens device for multi-angle inner wall detection as described above.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] Through the above optical system, the present invention realizes multi-angle optical imaging of the inner wall of a cylindrical product or a cavity workpiece, and six-angle images can be obtained through a single shot, presenting the entire inner wall situation completely, greatly saving space and cost.

[0028] The present invention has other characteristics and advantages, which will be obvious from the accompanying drawings incorporated herein and the subsequent specific embodiments, or will be described in detail in the accompanying drawings incorporated herein and the subsequent specific embodiments, and these accompanying drawings and specific embodiments are jointly used to explain the specific principles of the present invention. Description of the Drawings

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0030] Figure 1 It is a schematic structural diagram of an optical system of a lens device for multi-angle inner wall detection provided in the first embodiment of the present invention.

[0031] Figure 2 It is an optical path diagram of an optical system of a lens device for multi-angle inner wall detection provided in the first embodiment of the present invention.

[0032] Figure 3 It is a reflection component diagram with β1 = 0° provided in an embodiment of the present invention.

[0033] Figure 4 It is another reflection component diagram with β1 = 10° provided in an embodiment of the present invention.

[0034] Figure 5 It is an MTF transfer function curve diagram of an optical system of a lens device for multi-angle inner wall detection provided in an embodiment of the present invention.

[0035] Figure 6 It is an imaging diagram of the inner side wall of a cylindrical product provided in an embodiment of the present invention. Detailed implementation manners

[0036] To illustrate in detail the possible application scenarios, technical principles, specific implementable solutions, achievable purposes and effects of the present application, the following is described in detail with reference to the specific embodiments listed and in conjunction with the accompanying drawings. The embodiments described herein are only used to more clearly illustrate the technical solutions of the present application, and therefore are only used as examples and cannot be used to limit the protection scope of the present application.

[0037] Referring to "embodiment" herein means that a specific feature, structure or characteristic described in connection with the embodiment can be included in at least one embodiment of the present application. The term "embodiment" appearing in various positions in the specification does not necessarily refer to the same embodiment, nor does it particularly limit its independence or relevance to other embodiments. In principle, in the present application, as long as there is no technical contradiction or conflict, the technical features mentioned in each embodiment can be combined in any way to form corresponding implementable technical solutions.

[0038] Unless otherwise defined, the meanings of the technical terms used herein are the same as those commonly understood by those skilled in the technical field to which the present application belongs; the use of the relevant terms herein is only for describing specific embodiments and is not intended to limit the present application.

[0039] In the description of the present application, the term "and / or" is an expression used to describe the logical relationship between objects, indicating that there can be three relationships. For example, A and / or B means: there is A, there is B, and there is both A and B at the same time. In addition, the character " / " herein generally represents an "or" logical relationship between the associated objects.

[0040] In this application, terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual quantitative, primary-secondary, or sequential relationships between these entities or operations.

[0041] Without further limitation, in this application, the terms "comprising", "including", "having", or other similar expressions used in a statement are intended to cover non-exclusive inclusion. These expressions do not exclude the possibility that there may be additional elements in the process, method, or product that includes the described elements. Thus, a process, method, or product that includes a series of elements may include not only those defined elements, but also other elements not explicitly listed, or elements inherent to such a process, method, or product.

[0042] Similar to the understanding in the "Examination Guidelines", in this application, expressions such as "greater than", "less than", "exceeding", etc. are understood not to include the recited number; expressions such as "above", "below", "within", etc. are understood to include the recited number. In addition, in the description of the embodiments of this application, the meaning of "a plurality of" is two or more (including two). Similar expressions related to "multiple", such as "multiple groups", "multiple times", etc., are understood in the same way, unless otherwise specifically defined.

[0043] In the description of the embodiments of this application, the spatially related terms used, such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "perpendicular", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the specific embodiment or the drawings. This is only for the convenience of describing the specific embodiments of this application or for the reader's understanding, and does not indicate or imply that the device or component referred to must have a specific position, a specific orientation, or be constructed or operated in a specific orientation. Therefore, it should not be construed as a limitation on the embodiments of this application.

[0044] Unless otherwise clearly specified or limited, in the description of the embodiments of this application, the terms "installed", "connected", "joined", "fixed", "set", etc. should be understood in a broad sense. For example, the "connection" can be a fixed connection, a detachable connection, or an integral setting; it can be a mechanical connection, an electrical connection, or a communication connection; it can be a direct connection, or an indirect connection through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art to which this application pertains, the specific meanings of the above terms in the embodiments of this application can be understood according to specific circumstances.

[0045] Embodiment 1:

[0046] Please refer to Figure 1 and Figure 2 , Figure 1 which is a schematic structural diagram of an optical system of a lens device for multi - angle inner wall detection provided in Embodiment 1 of the present invention, Figure 2 and

[0047] As Figure 1 or Figure 2 shown, the optical system includes:

[0048] A reflection component T1 and an imaging lens group T2 arranged in sequence from the object side to the image side;

[0049] The reflection component T1 includes a first mirror group M1 and a second mirror group M2, and an annular light illumination source S0 is further provided between the first mirror M1 group and the second mirror group M2;

[0050] For easy understanding, please combine Figure 3 or Figure 4 , Figure 3 which is a diagram of a reflection component with β1 = 0° provided in an embodiment of the present invention, Figure 4 and

[0051] As Figure 3 shown, the included angle between the incident light of the reflection component T1 and the optical axis of the imaging lens group T2 is set as α, and as Figure 4 shown, the included angle between the first mirror group M1 and the optical axis of the imaging lens group T2 is set as β1, and the included angle between the second mirror group M2 and the optical axis of the imaging lens group T2 is set as β2;

[0052] In this embodiment, α, β1, and β2 satisfy the following relational expressions:

[0053] 10° ≤ α ≤ 60°, 15° ≤ β2 ≤ 40°, α = 2 * β2 - 2 * β1.

[0054] Specifically, in this embodiment, the first mirror M1 group includes six rectangular first plane mirrors evenly distributed around the optical axis; the second mirror group M2 includes six isosceles trapezoidal second plane mirrors evenly distributed around the optical axis and respectively used in one - to - one cooperation with the six first plane mirrors;

[0055] The side of the second plane mirror away from the first lens G1 is the narrower base of the isosceles trapezoid, and this narrower base is arranged close to the optical axis of the imaging lens group T2.

[0056] Specifically, the imaging lens group T2 includes a front group L1 with positive optical power, a diaphragm A0, and a rear group L2 with positive optical power, which are sequentially arranged from the object side to the image side;

[0057] The front group L1 includes a first lens G1 with positive optical power, a second lens G2 with positive optical power, and a third lens G3 with negative optical power, which are sequentially arranged from the object side to the image side. Among them, the second lens G2 and the third lens G3 are cemented into a first cemented lens group U1 with positive optical power;

[0058] The rear group L2 includes a fourth lens G4 with negative optical power, a fifth lens G5 with positive optical power, and a sixth lens G6 with positive optical power. Among them, the fourth lens G4 and the fifth lens G5 are cemented into a second cemented lens group U2 with negative optical power.

[0059] Further, the focal length of the first lens G1 is f G1 , and the focal length of the front group L1 is f L1 , f G1 and f L1 satisfy the relational expression: 1.20 < |f G1 / f L1 | < 1.90;

[0060] The focal length of the sixth lens G6 is f G6 , and the focal length of the rear group L2 is f L2 , f G6 and f L2 satisfy the relational expression: 0.70 < |f G6 / f L2 | < 1.25.

[0061] The Abbe number of the second lens G2 is V2, and the Abbe number of the third lens G3 is V3. V2 and V3 satisfy the relational expression: 10 < |V2 - V3| < 45;

[0062] The Abbe number of the fourth lens G4 is V4, and the Abbe number of the fifth lens G5 is V5. V4 and V5 satisfy the relational expression: 25 < |V4 - V5| < 55.

[0063] More specifically, the first lens G1, the second lens G2, the fifth lens G5, and the sixth lens G6 are all biconvex lenses, and the third lens G3 and the fourth lens G4 are both biconcave lenses.

[0064] The first lens G1, the second lens G2, the third lens G3, the fourth lens G4, the fifth lens G6, and the sixth lens G6 are all glass spherical lenses.

[0065] As an alternative embodiment, in this embodiment, the material of the first lens G1 is heavy phosphate crown glass, the material of the second lens G2 is fluor crown glass, the material of the third lens G3 is lanthanum flint glass, the material of the fourth lens G4 is heavy flint glass, the material of the fifth lens G6 is heavy phosphate crown glass, and the material of the sixth lens G6 is heavy lanthanum flint glass.

[0066] It should be noted that the optical axes of the first lens G1, the second lens G2, the third lens G3, the fourth lens G4, the fifth lens G6, and the sixth lens G6 all coincide with the optical axis of the imaging lens group T2;

[0067] The aperture of the aperture stop A0 is a circular hole, and the center of the circular hole is on the optical axis of the imaging lens group T2.

[0068] It can be understood that the aperture value of the aperture stop T needs to be adjusted correspondingly according to the specific application scenario.

[0069] To verify whether the above optical system meets the design purpose, the following is a specific application example given according to the above settings of this embodiment:

[0070] In this application example, the data of each lens of the optical system are shown in Table 1 below:

[0071] Table 1

[0072] Surface Radius (mm) Thickness (mm) Abbe number Angle with optical axis Object surface Plane 25 Mirror M1 Plane 37.6 0° Mirror M2 Plane 51.4 17.5° Front surface of G1 75.7 4.4 64.5 Rear surface of G1 -164.2 42.3 Front surface of U1 18.4 4.4 81 Bonding surface of U1 -107.4 7.6 47 Rear surface of U1 46.7 21.5 Diaphragm Plane 6.2 Front surface of U2 -10.3 9.9 23.5 Bonding surface of U2 28.8 10.0 64.5 Rear surface of U2 -20.5 1.9 Front surface of G6 72.8 2.8 28 Rear surface of G6 -51.7 39.1 Image surface Plane

[0073] It should be noted that in Table 1, the "front surface" corresponds to Figure 1 the left surface of the corresponding lens or lens group, and the "rear surface" corresponds to Figure 1 the right surface of the corresponding lens or lens group; or it can be understood that: the object side is on the Figure 1 left side, the image side (or image plane) is on the Figure 1 right side, the surface closer to the object side is the "front surface", and the surface closer to the image side is the "rear surface".

[0074] In this application example, as Figure 3 shown, the angle α between the incident light of the reflection device T1 and the optical axis of the imaging lens group T2 is 35°, the angle β1 between the first mirror group M1 and the optical axis of the imaging lens group T2 is 0°, the angle β2 between the second mirror group M2 and the optical axis of the imaging lens group T2 is 17.5°, the focal length f L1 of the front group L1 of the imaging lens group T2 is 54.63 mm, the focal length f L2 of the rear group L2 is 28.24 mm, the focal length f G1 of the first lens G1 is 86.23 mm, and the focal length f G6 of the sixth lens G6 is 30.25 mm.

[0075] Each relational expression:

[0076] α = 35°; β1 = 0°; β2 = 17.5°;

[0077] |f G1 / f L1 | = 1.58; |V2 - V3| = 34; |V4 - V5| = 41; |f G6 / f L2 | = 1.07.

[0078] Satisfy the relational expressions:

[0079] 10° ≤ α ≤ 60°, 15° ≤ β2 ≤ 40°, α = 2 * β2 - 2 * β1;

[0080] 1.20 < |f G1 / f L1 | < 1.90; 10 < |V2 - V3| < 45; 25 < |V4 - V5| < 55;

[0081] 0.70 < |f G6 / f L2 | < 1.25.

[0082] Please refer to Figure 5 and Figure 6 , Figure 5 which is the MTF (Modulation Transfer Function) transfer function curve graph of the optical system of a multi - angle inner - wall detection lens device provided by an embodiment of the present invention, Figure 6 which is the imaging graph of the inner side wall of a cylindrical product provided by an embodiment of the present invention;

[0083] As Figure 6 shown, through the above structure, optical imaging of the inner wall of a cylindrical product or a cavity workpiece at multiple angles is realized. By taking a single shot, images at six angles can be obtained, presenting the entire inner - wall situation completely, saving space and cost significantly. As Figure 5 shown, the highest resolution of this lens device can reach 65 lp / mm, and the maximum imaging circle is Φ10 mm.

[0084] Embodiment 2:

[0085] This embodiment provides a multi - angle inner - wall detection lens device, including the optical system of a multi - angle inner - wall detection lens device as described in Embodiment 1.

[0086] As Figure 1 or Figure 2 shown, this optical system includes:

[0087] A reflection component T1 and an imaging lens group T2 arranged in sequence from the object side to the image side;

[0088] The reflection component T1 includes a first mirror group M1 and a second mirror group M2, and an annular light illumination source S0 is further provided between the first mirror M1 group and the second mirror group M2;

[0089] For ease of understanding, please combine Figure 3 or Figure 4 , Figure 3 This is a diagram of a reflection component with β1 = 0° provided by an embodiment of the present invention, Figure 4 This is another diagram of a reflection component with β1 = 10° provided by an embodiment of the present invention;

[0090] As Figure 3 shown, the included angle between the incident light of the reflection component T1 and the optical axis of the imaging lens group T2 is set as α, and as Figure 4 shown, the included angle between the first mirror group M1 and the optical axis of the imaging lens group T2 is set as β1, and the included angle between the second mirror group M2 and the optical axis of the imaging lens group T2 is set as β2;

[0091] In this embodiment, α, β1, and β2 satisfy the following relational expressions:

[0092] 10° ≤ α ≤ 60°, 15° ≤ β2 ≤ 40°, α = 2 * β2 - 2 * β1.

[0093] Specifically, in this embodiment, the first mirror M1 group includes six rectangular first plane mirrors evenly distributed around the optical axis; the second mirror group M2 includes six isosceles trapezoidal second plane mirrors evenly distributed around the optical axis and respectively used in one-to-one cooperation with the six first plane mirrors;

[0094] The side of the second plane mirror away from the first lens G1 is the narrower base of the isosceles trapezoid, and this narrower base is arranged close to the optical axis of the imaging lens group T2.

[0095] Specifically, the imaging lens group T2 includes a front group L1 with positive optical power, a stop A0, and a rear group L2 with positive optical power arranged in sequence from the object side to the image side;

[0096] The front group L1 includes a first lens G1 with positive optical power, a second lens G2 with positive optical power, and a third lens G3 with negative optical power arranged in sequence from the object side to the image side. Among them, the second lens G2 and the third lens G3 are cemented into a first cemented lens group U1 with positive optical power;

[0097] The rear group L2 includes a fourth lens G4 with negative optical power, a fifth lens G5 with positive optical power, and a sixth lens G6 with positive optical power. Among them, the fourth lens G4 and the fifth lens G5 are cemented into a second cemented lens group U2 with negative optical power.

[0098] Further, the focal length of the first lens G1 is f G1 , the focal length of the front group L1 is f L1 , f G1 and f L1 satisfy the relational expression: 1.20 < |f G1 / f L1 | < 1.90;

[0099] The focal length of the sixth lens G6 is f G6 , the focal length of the rear group L2 is f L2 , f G6 and f L2 satisfy the relational expression: 0.70 < |f G6 / f L2 | < 1.25.

[0100] The Abbe number of the second lens G2 is V2, the Abbe number of the third lens G3 is V3, and V2 and V3 satisfy the relational expression: 10 < |V2 - V3| < 45;

[0101] The Abbe number of the fourth lens G4 is V4, the Abbe number of the fifth lens G5 is V5, and V4 and V5 satisfy the relational expression: 25 < |V4 - V5| < 55.

[0102] More specifically, the first lens G1, the second lens G2, the fifth lens G5, and the sixth lens G6 are all biconvex lenses, and the third lens G3 and the fourth lens G4 are both biconcave lenses.

[0103] The first lens G1, the second lens G2, the third lens G3, the fourth lens G4, the fifth lens G6, and the sixth lens G6 are all glass spherical lenses.

[0104] As an alternative implementation, in this embodiment, the material of the first lens G1 is heavy phosphate crown glass, the material of the second lens G2 is fluor crown glass, the material of the third lens G3 is lanthanum flint glass, the material of the fourth lens G4 is heavy flint glass, the material of the fifth lens G6 is heavy phosphate crown glass, and the material of the sixth lens G6 is heavy lanthanum flint glass.

[0105] It should be noted that the optical axes of the first lens G1, the second lens G2, the third lens G3, the fourth lens G4, the fifth lens G6, and the sixth lens G6 all coincide with the optical axis of the imaging lens group T2;

[0106] The aperture of the aperture stop A0 is a circular hole, and the center of the circular hole is on the optical axis of the imaging lens group T2.

[0107] It can be understood that the aperture value of the aperture stop T needs to be adjusted correspondingly according to the specific application scenario.

[0108] In summary, the angle between the incident light of the lens device and the optical axis of the imaging lens group T2 is in the range of 10° to 60°, and it can detect cylindrical products or cavity workpieces with an inner diameter of 1 mm to 15 mm. The range of the ratio of the measurable depth to the inner diameter can reach 5.6:1 to 0.6:1. In addition, the reflection device includes an annular light illumination source S0, and the integrated illumination design is more convenient for lighting.

[0109] As described above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than limiting it; although the present invention 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 recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and 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 invention.

Claims

1. An optical system of a lens device for multi-angle inner wall detection, characterized in that, It includes a reflection component T1 and an imaging lens group T2 arranged in sequence from the object side to the image side; The reflection component T1 includes a first mirror group M1 and a second mirror group M2, and an annular light illumination source S0 is also arranged between the first mirror M1 group and the second mirror group M2; The included angle between the incident light of the reflection component T1 and the optical axis of the imaging lens group T2 is ∝, the included angle between the first mirror group M1 and the optical axis of the imaging lens group T2 is β1, and the included angle between the second mirror group M2 and the optical axis of the imaging lens group T2 is β2. α, β1, and β2 satisfy the following relational expressions: 10°≤α≤60°，15°≤β2≤40°，α＝2*β2-2*β1。 2. The optical system of a lens device for multi-angle inner wall detection according to claim 1, characterized in that, The imaging lens group T2 includes a front group L1 with positive optical power, a diaphragm A0, and a rear group L2 with positive optical power arranged in sequence from the object side to the image side; The front group L1 includes a first lens G1 with positive optical power, a second lens G2 with positive optical power, and a third lens G3 with negative optical power arranged in sequence from the object side to the image side. Among them, the second lens G2 and the third lens G3 are cemented into a first cemented lens group U1 with positive optical power; The rear group L2 includes a fourth lens G4 with negative optical power, a fifth lens G5 with positive optical power, and a sixth lens G6 with positive optical power. Among them, the fourth lens G4 and the fifth lens G5 are cemented into a second cemented lens group U2 with negative optical power.

3. The optical system of a lens device for multi-angle inner wall detection according to claim 2, characterized in that, The focal length of the first lens G1 is f G1 , and the focal length of the front group L1 is f L1 , f G1 and f L1 satisfy the relationship: 1.20 < |f G1 / f L1 | < 1.90; The focal length of the sixth lens G6 is f G6 , and the focal length of the rear group L2 is f L2 , f G6 and f L2 satisfy the relation: 0.70 < |f G6 / f L2 | < 1.

25.

4. The optical system of a lens device for multi-angle inner wall detection according to claim 3, characterized in that The Abbe number of the second lens G2 is V2, and the Abbe number of the third lens G3 is V3. V2 and V3 satisfy the relational expression: 10 < |V2 - V3| < 45; The Abbe number of the fourth lens G4 is V4, and the Abbe number of the fifth lens G5 is V5. V4 and V5 satisfy the relational expression: 25 < |V4 - V5| < 55.

5. The optical system of a lens device for multi-angle inner wall detection according to claim 2, characterized in that, The first lens G1, the second lens G2, the fifth lens G5, and the sixth lens G6 are all biconvex lenses, and the third lens G3 and the fourth lens G4 are both biconcave lenses.

6. The optical system of a lens device for multi-angle inner wall detection according to claim 5, characterized in that, The first lens G1, the second lens G2, the third lens G3, the fourth lens G4, the fifth lens G6, and the sixth lens G6 are all spherical glass lenses.

7. The optical system of a lens device for multi-angle inner wall detection according to claim 6, characterized in that, The material of the first lens G1 is heavy phosphate crown glass, the material of the second lens G2 is fluor crown glass, the material of the third lens G3 is lanthanum flint glass, the material of the fourth lens G4 is heavy flint glass, the material of the fifth lens G6 is heavy phosphate crown glass, and the material of the sixth lens G6 is heavy lanthanum flint glass.

8. The optical system of a lens device for multi-angle inner wall detection according to claim 2, characterized in that, The first mirror M1 group includes six rectangular first plane mirrors evenly distributed around the optical axis; the second mirror group M2 includes six isosceles trapezoidal second plane mirrors evenly distributed around the optical axis and respectively used in one-to-one cooperation with the six first plane mirrors; The side of the second plane mirror away from the first lens G1 is the narrower base of the isosceles trapezoid, and the narrower base is arranged close to the optical axis of the imaging lens group T2.

9. The optical system of a lens device for multi-angle inner wall detection according to claim 2, characterized in that, The optical axes of the first lens G1, the second lens G2, the third lens G3, the fourth lens G4, the fifth lens G6, and the sixth lens G6 all coincide with the optical axis of the imaging lens group T2; The aperture of the diaphragm A0 is a circular hole, and the center of the circular hole is on the optical axis of the imaging lens group T2.

10. A lens device for multi-angle inner wall detection, characterized in that, It includes an optical system of a lens device for multi-angle inner wall detection as described in any one of claims 1 - 9.

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