High-magnification magnifier lens

Abstract

The utility model discloses a high-magnification optical lens, and aims to provide a magnification exceeding 30 times and ensure a clear imaging effect. The lens sequentially comprises a first lens (L1), a second lens (L2) and a third lens (L3) from an object side to an imaging surface along an optical axis. The first lens has positive focal power, the object side surface is a convex surface, and the image side surface is a concave surface; the second lens has positive focal power, and the object side surface and the image side surface are convex surfaces; the third lens has positive focal power, and the object side surface and the image side surface are convex surfaces. The optical parameters of the lens are precisely designed to meet the specific relation of the focal length ratio, the curvature radius ratio and the thickness ratio, so that the imaging quality is optimized, and the manufacturing tolerance is controlled. The specific parameters include that the focal length f1 of the first lens and the focal length f2 of the second lens meet the condition that f1 / f2 is larger than 1 and smaller than 1.5, and the focal length f2 of the second lens and the focal length f3 of the third lens meet the condition that f2 / f3 is larger than 1.2 and smaller than 1.5.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of imaging lenses, in particular to a high-magnification magnifying lens. BACKGROUND

[0002] In the field of optical imaging, high-magnification magnifying lenses are widely used in various precision detection, observation and measurement scenarios, such as scientific research, medical diagnosis, industrial detection, etc. However, traditional high-magnification magnifying lenses have certain limitations in terms of imaging quality, magnification, and stability of the optical system. For example, some magnifying lenses have low magnification, which cannot meet the high-precision observation requirements of small objects or details; while some magnifying lenses can provide high magnification, but the imaging quality is poor, with aberrations, distortion and other problems, affecting the observation effect. In addition, the manufacturing tolerance control of optical lenses is also a key factor, and too large tolerance may lead to unstable optical performance, affecting the consistency of imaging quality. Therefore, it is of great practical significance to develop a magnifying lens that can provide high magnification and clear imaging with stable and reliable optical performance. SUMMARY

[0003] The present application aims to provide a high-magnification magnifying lens that can achieve a magnification of more than 30 times and provide clear imaging effect, while ensuring the stability and consistency of the imaging quality of the optical lens by reasonably designing the optical parameters and strictly controlling the manufacturing tolerance.

[0004] To achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0005] A high-magnification magnifying lens, arranged along the optical axis from the object side to the imaging surface in order: a first lens (L1), a second lens (L2), and a third lens (L3):

[0006] The first lens (L1) has positive focal power, with a convex surface on the object side near the optical axis and a concave surface on the image side;

[0007] The second lens (L2) has positive focal power, with a convex surface on the object side near the optical axis and a convex surface on the image side;

[0008] The third lens (L3) has positive focal power, with a convex surface on the object side and a convex surface on the image side;

[0009] Wherein, the focal length f1 of the first lens and the focal length f2 of the second lens satisfy: 1 < f1 / f2 < 1.5; the focal length f2 of the second lens and the focal length f3 of the third lens satisfy: 1.2 < f2 / f3 < 1.5.

[0010] The high-magnification magnifying lens, characterized in that the effective focal length f of the high-magnification magnifying lens, the effective focal length f of the high-magnification magnifying lens and the focal length f1 of the first lens, the focal length f2 of the second lens and the focal length f3 of the third lens respectively satisfy the following relationship:

[0011] -9 < f < -8;

[0012] -3.1 < f1 / f < -2.9;

[0013] -2.8 < f2 / f < -2.5;

[0014] -2 < f3 / f < -1.5.

[0015] The high-magnification magnifying lens, characterized in that the effective focal length f of the high-magnification magnifying lens, the effective focal length f of the high-magnification magnifying lens and the focal length f1 of the first lens, the focal length f2 of the second lens and the focal length f3 of the third lens respectively satisfy the following relationship:

[0016] 0.2 < R1 / R2 < 0.3;

[0017] -0.21 < R3 / R4 < -0.17;

[0018] -0.35 < R5 / R6 < -0.28.

[0019] The high-magnification magnifying lens, characterized in that the high-magnification magnifying lens satisfies the following relationship:

[0020] 0.32 < T1 / ∑T < 0.36;

[0021] 0.34 < T2 / ∑T < 0.38;

[0022] 0.27 < T3 / ∑T < 0.31;

[0023] Wherein, ∑T is the sum of the lens thickness of the first lens, the second lens and the third lens on the optical axis, T1 is the lens thickness of the first lens on the optical axis, T2 is the lens thickness of the second lens on the optical axis, and T3 is the lens thickness of the third lens on the optical axis.

[0024] The high-magnification magnifying lens, characterized in that the magnification of the high-magnification magnifying lens is > 30 times, which can provide clear imaging effect, and the manufacturing tolerances of each lens of the magnifying lens are controlled within a predetermined range, so as to ensure the stability and consistency of the imaging quality of the high-magnification magnifying lens.

[0025] Compared with the prior art, the present application has the following advantages:

[0026] 1) The high magnification magnifying lens of the present application has a specific surface shape setting and a reasonable power distribution, so that the lens has a large magnification, provides clear imaging quality, and also has a good tolerance control;

[0027] 2) The high magnification magnifying lens of the present application has low image distortion and small image distortion, which can effectively ensure high resolution and high definition of the observed image. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is a structural schematic diagram of the overall structure of the high magnification magnifying lens.

[0029] Figure 2 is a sagittal chromatic aberration diagram (mm) of the high magnification magnifying lens.

[0030] Figure 3 is a field curvature distortion diagram (%) of the high magnification magnifying lens.

[0031] Figure 4 is a diffraction MTF diagram of the high magnification magnifying lens. DETAILED DESCRIPTION

[0032] For a better understanding of the present application, various aspects of the present application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely descriptive of embodiments of the present application and are not intended in any way to limit the scope of the present application. Throughout the specification, like reference numerals refer to like elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0033] It should be noted that in the present specification, the expressions first, second, third, etc. are used only to distinguish one feature from another feature, and do not represent any limitation on the features. Therefore, the first lens discussed below can also be referred to as the second lens or the third lens without departing from the teachings of the present application.

[0034] In the drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for ease of explanation. Specifically, the shape of the spherical surface or aspherical surface shown in the drawings is shown by way of example. That is, the shape of the spherical surface or aspherical surface is not limited to the shape of the spherical surface or aspherical surface shown in the drawings. The drawings are merely examples and are not drawn strictly to scale.

[0035] In the present disclosure, the paraxial region refers to a region near the optical axis. If the lens surface is convex and the position of the convex surface is not defined, it means that the lens surface is convex at least in the paraxial region. If the lens surface is concave and the position of the concave surface is not defined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the object is referred to as the object side surface of the lens, and the surface of each lens closest to the imaging surface is referred to as the image side surface of the lens.

[0036] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0037] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

[0038] The high-power magnifying lens provided by the embodiment of the present application sequentially arranges a first lens (L1), a second lens (L2), and a third lens (L3) along the optical axis from the object side to the imaging surface.

[0039] In the present embodiment, the first lens can have a positive focal power, the object side surface thereof is convex at the near optical axis, and the image side surface thereof is concave; the second lens can have a positive focal power, the object side surface thereof is convex at the near optical axis, and the image side surface thereof is convex; and the third lens can have a positive focal power, the object side surface thereof is convex, and the image side surface thereof is convex.

[0040] In the present embodiment, the high-power magnifying lens can further include a diaphragm, which can be located between the image side and the third lens. It can be understood that the diaphragm is used to limit the light output to change the brightness of the imaging.

[0041] In the present embodiment, the focal length f2 of the second lens and the focal length f3 of the third lens satisfy: 1.2 < f2 / f3 < 1.5. By reasonably setting the focal length relationship of the last two lenses, the light rays can be diverged to some extent and the aberration can be effectively corrected, which is beneficial to realize large target surface imaging of the lens, and at the same time, the system has a relatively long focal length, which satisfies the performance characteristics of long focal length and large target surface.

[0042] In the present embodiment, the curvature radius R1 of the object side surface of the first lens and the curvature radius R2 of the image side surface of the first lens satisfy: 0.2 < R1 / R2 < 0.3. By reasonably setting the meniscus shape of the first lens, as many light rays as possible can enter the system, so that the lens has a wider observation range.

[0043] In this embodiment, the effective focal length f of the high-magnification magnifying lens and the focal length f2 of the second lens satisfy the condition: -2.8 < f2 / f < -2.5. The object-side radius of curvature R3 of the second lens and the image-side radius of curvature R4 of the second lens satisfy the condition: -0.21 < R3 / R4 < -0.17. Satisfying the above conditions can reduce the convergence of light, which helps to avoid excessive light refraction caused by excessive concentration of the optical focal length of the first lens, and reduces the difficulty of aberration correction.

[0044] In this embodiment, the effective focal length f of the high-magnification magnifying lens and the focal length f3 of the third lens satisfy the following condition: -2 < f3 / f < -1.5; the image-side radius of curvature R6 of the third lens and the effective focal length f of the optical lens satisfy the following condition: 3 < R6 / f < 5; the object-side radius of curvature R5 of the third lens and the image-side radius of curvature R6 of the third lens satisfy the following condition: -0.35 < R5 / R6 < -0.28. Meeting these conditions facilitates further convergence of light rays, allowing diverging light rays to smoothly enter the rear optical system, thus achieving higher-quality imaging from the lens.

[0045] In this embodiment, the high-magnification magnifying lens consists of three lenses, with the following specific parameters:

[0046] First lens (L1): focal length f1 = 25.2019 mm, object side radius of curvature R1 = 9.9036 mm, image side radius of curvature R2 = 43.8198 mm, lens thickness T1 = 3.34 mm;

[0047] Second lens (L2): focal length f2 = 21.8585 mm, object side radius of curvature R3 = 12.5682 mm, image side radius of curvature R4 = -67.3474 mm, lens thickness T2 = 3.55 mm;

[0048] Third lens (L3): focal length f3 = 15.6207 mm, object side radius of curvature R5 = 9.7150 mm, image side radius of curvature R6 = -33.1636 mm, lens thickness T3 = 2.84 mm;

[0049] The effective focal length of the optical lens is f = -8.3276 mm, and the total thickness is ∑T = 9.73 mm.

[0050] By designing the parameters described above, the relationships between focal length ratio, radius of curvature ratio, and thickness ratio as stated in the claims are satisfied, enabling a magnification exceeding 30x and providing clear imaging. Simultaneously, during the manufacturing process, strict control over the manufacturing tolerances of each lens ensures the stability and consistency of the high-magnification magnifying lens's imaging quality.

[0051] The following table is the lens data sheet for the embodiment:

[0052] Table 1 Lens data for high-magnification magnifying glasses

[0053] Surface No. Surface Type Curvature Radius / (mm) Thickness / (mm) Material (Refractive Index: Abbe Number) Object Plane Spherical Infinite -250 S1 Spherical Infinite 13.5 S2 Aspherical 9.9036 3.34 1.50：57.18 S3 Aspherical 43.8198 6.8364 S4 Aspherical 12.5682 3.55 1.50：57.18 S5 Aspherical -67.3474 50 S6 Aspherical 9.7150 2.84 1.50：57.18 S7 Diaphragm -33.1636 0.55 Spherical Infinite Spherical 1 S9 Infinite Image Plane 21.0385 Spherical Infinite ​ 0

[0054] Table 2 Surface coefficients of aspherical lenses in high-magnification magnifying glasses

[0055]

[0056]

[0057] The methods described in this specification are merely preferred embodiments and are not intended to limit the inventive concept and design techniques. Anything that does not depart from the inventive concept and design techniques should fall within the protection scope of this invention.

Claims

1. A high-magnification magnifying lens, characterized in that, A first lens (L1), a second lens (L2), and a third lens (L3) are sequentially arranged along the optical axis from the object side to the imaging plane: The first lens (L1) with positive optical power has an object-side surface that is convex near the optical axis and an image-side surface that is concave. The second lens (L2) with positive optical power has an object-side surface that is convex near the optical axis and an image-side surface that is convex. The third lens (L3) with positive optical power has a convex object side and a convex image side. Wherein, the focal length f1 of the first lens and the focal length f2 of the second lens satisfy: 1 ​​< f1 / f2 < 1.5; the focal length f2 of the second lens and the focal length f3 of the third lens satisfy: 1.2 < f2 / f3 < 1.

5.

2. The high-magnification magnifying lens according to claim 1, characterized in that, The effective focal length f of the high-magnification magnifying lens, the effective focal length f of the high-magnification magnifying lens, and the focal lengths f1, f2, and f3 of the first lens and the third lens respectively satisfy the following relationships: -9＜f＜-8； -3.1 < f1 / f < -2.9; -2.8 < f² / f < -2.5; -2 < f3 / f < -1.

5.

3. The high-magnification magnifying lens according to claim 1, characterized in that, The object-side radius of curvature R1 of the first lens and the image-side radius of curvature R2 of the first lens, the object-side radius of curvature R3 of the second lens and the image-side radius of curvature R4 of the second lens, and the object-side radius of curvature R5 of the third lens and the image-side radius of curvature R6 of the third lens respectively satisfy the following relationships: 0.2 < R1 / R2 < 0.3; -0.21 < R3 / R4 < -0.17; -0.35 < R5 / R6 < -0.

28.

4. The high-magnification magnifying lens according to claim 1, characterized in that, The high-magnification magnifying lens satisfies the following relationship: 0.32 < T1 / ∑T < 0.36; 0.34 < T² / ∑T < 0.38; 0.27 < T3 / ∑T < 0.31; Where ∑T is the sum of the lens thicknesses of the first lens, the second lens, and the third lens on the optical axis, T1 is the lens thickness of the first lens on the optical axis, T2 is the lens thickness of the second lens on the optical axis, and T3 is the lens thickness of the third lens on the optical axis.

5. The high-magnification magnifying lens according to claim 1, characterized in that, The high-magnification magnifying lens has a magnification of >30x, providing clear imaging results. At the same time, the manufacturing tolerances of each lens in the high-magnification magnifying lens are controlled within a preset range to ensure the stability and consistency of the imaging quality of the high-magnification magnifying lens.

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