Machine vision prime lens with improved structure and focal length of 35mm

Abstract

The utility model discloses a machine vision prime lens with an improved structure and a focal length of 35mm, which comprises a first lens, a second lens arranged on the right side of the first lens, a third lens arranged on the right side of the second lens, a fourth lens arranged on the right side of the third lens, and a diaphragm arranged between the fourth lens and the third lens. A fifth lens is arranged on the right side of the fourth lens, an imaging surface is arranged on the right side of the fifth lens, the focal length of the first lens is G1, the focal length of the fourth lens is G4, the focal length of the lens is f, and the optical system meets the relational expression 0.8 lt; g1 / flt; 1.3, 0.6 lt, 1.3, 0.6 lt; g4 / flt; and 0.8. The utility model has the advantages of novel design, simple structure, simple and convenient assembly, low cost, good optical performance, clear imaging and high resolution, and can realize the change of the object distance from 0.1 m to infinity.

Description

Technical Field

[0001] This utility model relates to the field of lens technology, and in particular to a structurally improved 35mm focal length machine vision fixed-focus lens. Background Technology

[0002] In today's rapidly developing industrial automation, machine vision fixed-focus lenses are widely used in automated production equipment. To meet the accuracy and precision requirements of automated equipment in production, inspection, and measurement, machine vision lenses must possess clear and stable imaging, low distortion, wide working distance, and a large field of view. Traditional machine vision lenses mostly have a resolution of one or two million pixels, which is insufficient in clarity and has distortion greater than 1%.

[0003] Chinese utility model patent with patent number ZL 202022378614.7 and titled "A 35mm focal length machine vision fixed-focus lens" discloses the following technical solution:

[0004] A 35mm focal length machine vision fixed-focus lens includes a movable lens group and a fixed lens group, which are arranged sequentially. The movable lens group includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens, arranged from left to right. The fixed lens group includes an eighth lens and a ninth lens, arranged from left to right.

[0005] It should be noted that the aforementioned lens uses a multi-lens combination, which has a complex structure, resulting in difficult assembly and high production costs. Moreover, it can only achieve clear imaging within an object distance of 0.3m to infinity, and cannot achieve a range from 0.1m to infinity. Utility Model Content

[0006] The purpose of this invention is to provide a structurally improved 35mm focal length machine vision fixed-focus lens to address the shortcomings of existing technologies. This structurally improved 35mm focal length machine vision fixed-focus lens features a novel design, simple structure, easy assembly, low cost, and excellent optical performance, achieving clear imaging and high resolution, and enabling object distances from 0.1m to infinity.

[0007] To achieve the above objectives, this utility model is implemented through the following technical solution.

[0008] The application discloses a focal length 35mm machine vision fixed focus lens with a structure improvement, which comprises a first lens, a second lens arranged on the right side of the first lens, a third lens arranged on the right side of the second lens, a fourth lens arranged on the right side of the third lens, an aperture arranged between the fourth lens and the third lens, a fifth lens arranged on the right side of the fourth lens, and an imaging surface arranged on the right side of the fifth lens.

[0009] The first lens, the second lens, the third lens, the fourth lens and the aperture form a moving lens group A, and the fifth lens is a fixed lens group B.

[0010] The lens surfaces of the first lens, the second lens, the third lens and the fourth lens are all spherical surfaces, and the lens surface of the fifth lens is a plane.

[0011] The aperture of the aperture is in the range of 0.5f to 1.5f. The aperture of the aperture is adjustable.

[0012] The refractive indexes of the first lens to the fourth lens are n1, n2, n3 and n4 in sequence, the Abbe numbers of the first lens to the fourth lens are v1, v2, v3 and v4 in sequence, and the following relationship formulas are satisfied: 1.5 < n1 < 1.8, 58 < v1 < 65.3; 1.4 < n2 < 1.7, 57.0 < v2 < 62.0; 1.6 < n3 < 1.8, 25.6 < v3 < 29.8; and 1.6 < n4 < 1.8, 47.3 < v4 < 52.1.

[0013] The beneficial effects of this utility model are as follows: The 35mm focal length machine vision fixed-focus lens with improved structure described in this utility model includes a first lens, a second lens mounted on the right side of the first lens, a third lens mounted on the right side of the second lens, a fourth lens mounted on the right side of the third lens, and an aperture stop between the fourth lens and the third lens. A fifth lens is mounted on the right side of the fourth lens, and an imaging plane is mounted on the right side of the fifth lens. The focal length of the first lens is G1, the focal length of the fourth lens is G4, the focal length of the lens is f, and the optical system satisfies the relationship 0.8 < |G1 / f| < 1.3, 0.6 < |G4 / f| < 0.8. This invention features a fixed lens group that remains stationary, while a movable lens group reciprocates along the optical axis, driven by the lens's mechanical structure. The center distance between the fixed and movable lens groups varies between 2.766mm and 3.88mm, while other intervals and the optical back focal length remain constant. This lens can achieve an object distance ranging from 0.1m to infinity. Therefore, this invention has the advantages of novel design, simple structure, easy assembly, low cost, good optical performance, clear imaging, high resolution, and the ability to achieve an object distance ranging from 0.1m to infinity. Attached Figure Description

[0014] The present invention will be further described below with reference to the accompanying drawings, but the embodiments in the drawings do not constitute any limitation on the present invention.

[0015] Figure 1 This is a schematic diagram of the structure of this utility model;

[0016] Figure 2 This is a light diagram of the present invention.

[0017] exist Figure 1 This includes:

[0018] 1 — First lens 2 — Second lens

[0019] 3 – Third lens; 4 – Fourth lens

[0020] 5 – Aperture; 6 – Five lenses

[0021] 7—Imaging plane. Detailed Implementation

[0022] The present invention will now be described in conjunction with specific embodiments.

[0023] like Figure 1As shown in the figure, a structure improved focal length 35mm machine vision fixed focus lens, including first lens 1, first lens 1 right side is equipped with the second lens 2, second lens 2 right side is equipped with the third lens 3, third lens 3 right side is equipped with the fourth lens 4, and fourth lens 4 and third lens 3 between being equipped with diaphragm 5, fourth lens 4 right side is equipped with the fifth lens 6, and fifth lens 6 right side is equipped with imaging surface 7, the focal length of first lens 1 is G1, the focal length of fourth lens 4 is G4, the focal length of lens is f, and the optical system satisfies the relationship 0.8<|G1 / f|<1.3, 0.6<|G4 / f|<0.8.

[0024] As preferred in the embodiment, the first lens 1, the second lens 2, the third lens 3, the fourth lens 4 and the diaphragm 5 form a moving lens group A, and the fifth lens (6) is a fixed lens group B.

[0025] As preferred in the embodiment, the lens surfaces of the first lens 1, the second lens 2, the third lens 3 and the fourth lens 4 are spherical surfaces, and the lens surfaces of the fifth lens 6 are all planar surfaces.

[0026] As preferred in the embodiment, the aperture of the diaphragm 5 is Adjustable.

[0027] Further, the refractive indices of the first lens 1 to the fourth lens 4 are n1, n2, n3 and n4 in sequence, and the Abbe numbers of the first lens 1 to the fourth lens 4 are v1, v2, v3 and v4 in sequence, satisfying the following relationship 1.5<n1<1.8, 58<v1<65.3; 1.4<n2<1.7, 57.0<v2<62.0; 1.6<n3<1.8, 25.6<v3<29.8; 1.6<n4<1.8, 47.3<v4<52.1.

[0028] The embodiment of the utility model provides a structure improved focal length 35mm machine vision fixed focus lens, the following table 1 lists the related parameters of each lens, including surface type, curvature radius, thickness, the refractive index of material and Abbe number:

[0029]

[0030] Table 1

[0031] In the table 1, the optical system surfaces are arranged in sequence, and are called lens front surface on the object side and lens rear surface on the image side. S1 and S2 are the front surface and the rear surface of the first lens; S3 and S4 are the front surface and the rear surface of the second lens; S5 and S6 are the front surface and the rear surface of the third lens; S7 and S8 are the front surface and the rear surface of the fourth lens. The curvature radius value is positive, indicating that the curvature center is on the image side; the curvature radius value is negative, indicating that the curvature center is on the object side. The thickness value represents the distance between the current optical surface and the next surface intersection point on the optical axis. The refractive index represents the refractive index of the medium between the current surface and the next surface. When the refractive index is blank, it represents the refractive index of air.

[0032] It needs to be further explained that the utility model discloses a fixed lens group B is fixed immovably, and the moving lens group A is driven by the lens mechanical structure and reciprocates along the optical axis, and the center distance between the fixed lens group and the moving lens group floats and changes between 2.766mm-3.88mm, and the remaining interval and the optical back focal length are invariable, and the lens can realize the change of the object distance 0.1m to infinity. Therefore, the utility model has the advantages of novel design, simple structure, simple assembly, low cost, good optical performance, clear imaging, high resolution and the change of the object distance 0.1m to infinity.

[0033] The above is only the preferred embodiment of the utility model, and for the ordinary skilled person in the art, the specific implementation mode and application range can be changed according to the thought of the utility model, and the content of the specification should not be understood as the limitation of the utility model.

Claims

1. A structurally improved focal length 35mm machine vision prime lens characterized by: The first lens (1) is provided with the second lens (2) on the right side, the third lens (3) on the right side of the second lens (2), the fourth lens (4) on the right side of the third lens (3), the diaphragm (5) between the fourth lens (4) and the third lens (3), the fifth lens (6) on the right side of the fourth lens (4), and the imaging surface (7) on the right side of the fifth lens (6), the focal length of the first lens (1) is G1, the focal length of the fourth lens (4) is G4, the focal length of the lens is f, and the optical system satisfies the relationship 0.8<|G1 / f|<1.3, 0.6<|G4 / f|<0.

8.

2. A structurally improved focal length 35mm machine vision prime lens according to claim 1, characterized in that: The first lens (1), the second lens (2), the third lens (3), the fourth lens (4) and the diaphragm (5) form a moving lens group (A), and the fifth lens (6) is a fixed lens group (B).

3. A structurally improved focal length 35mm machine vision prime lens according to claim 1, characterized in that: The lens surfaces of the first lens (1), the second lens (2), the third lens (3) and the fourth lens (4) are spherical surfaces, and the lens surfaces of the fifth lens (6) are flat surfaces.

4. The structurally improved 35mm focal length machine vision prime lens of claim 1, wherein: The aperture of the diaphragm (5) is adjustable between ∅8.3mm-∅1.1mm.

5. A structurally improved 35mm focal length machine vision fixed-focus lens according to claim 1, characterized in that: The refractive indices of the first lens (1) to the fourth lens (4) are n1, n2, n3, n4 in turn, the Abbe numbers of the first lens (1) to the fourth lens (4) are v1, v2, v3, v4 in turn, and the following relationships are satisfied 1.5<n1<1.8, 58<v1<65.3; 1.4<n2<1.7, 57.0<v2<62.0; 1.6<n3<1.8, 25.6<v3<29.8; 1.6<n4<1.8, 47.3<v4<52.1.

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