High-magnification magnifier lens

Abstract

The invention 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 invention relates to the technical field of imaging lenses, and particularly to a high-magnification magnifying glass lens. Background Art

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

[0003] The present invention aims to provide a high-magnification magnifying glass lens that can achieve a magnification of more than 30 times and provide clear imaging effects. At the same time, by reasonably designing optical parameters and strictly controlling manufacturing tolerances, the stability and consistency of the imaging quality of the optical lens can be ensured.

[0004] To achieve the above object, the present invention adopts the following technical solutions: A high-magnification magnifying glass lens, which successively 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: The first lens (L1) with positive optical power, whose object side is convex near the optical axis and whose image side is concave; The second lens (L2) with positive optical power, whose object side is convex near the optical axis and whose image side is convex; The third lens (L3) with positive optical power, whose object side is convex and whose image side is convex; 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.

[0005] The high-magnification magnifying glass lens is characterized in that the effective focal length f of the high-magnification magnifying glass lens, the effective focal length f of the high-magnification magnifying glass 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 relational expressions: -9 < f < -8; -3.1 < f1 / f < -2.9; -2.8 < f2 / f < -2.5; -2 < f3 / f < -1.5.

[0006] The high-magnification magnifying glass lens described above is characterized in that the curvature radius R1 of the object side surface of the first lens, the curvature radius R2 of the image side surface of the first lens, the curvature radius R3 of the object side surface of the second lens, the curvature radius R4 of the image side surface of the second lens, and the curvature radius R5 of the object side surface of the third lens and the curvature radius R6 of the image side surface of the third lens respectively satisfy the following relational expressions: 0.2 < R1 / R2 < 0.3; -0.21 < R3 / R4 < -0.17; -0.35 < R5 / R6 < -0.28.

[0007] The high-magnification magnifying glass lens described above is characterized in that the high-magnification magnifying glass lens satisfies the following relational expression: 0.32 < T1 / ∑T < 0.36; 0.34 < T2 / ∑T < 0.38; 0.27 < T3 / ∑T < 0.31; Wherein, ∑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.

[0008] The high-magnification magnifying glass lens described above is characterized in that the magnification of the high-magnification magnifying glass lens > 30 times, and it can provide a clear imaging effect. At the same time, the manufacturing tolerances of each lens of the magnifying glass are controlled within a preset range to ensure the stability and consistency of the imaging quality of the high-magnification magnifying glass lens.

[0009] Compared with the prior art, the present invention has the following advantages: 1) The high-magnification magnifying glass lens of the present invention, through specific surface shape settings and reasonable optical power distribution, enables the lens to have a large magnification, provide clear imaging quality, and at the same time control the tolerances well; 2) The high-magnification magnifying glass lens of the present invention has low image distortion and small image distortion, and can effectively ensure the high resolution and high clarity of the observed image. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is a schematic structural diagram of the overall structure of the high-magnification magnifying glass lens.

[0011] Figure 2 is the lateral chromatic aberration diagram (mm) of this high-magnification magnifying glass lens.

[0012] Figure 3 is the field curvature and distortion diagram (%) of this high-magnification magnifying glass lens.

[0013] Figure 4 is the diffraction MTF diagram of this high-magnification magnifying glass lens. Detailed implementation manners

[0014] To better understand the present application, more detailed descriptions will be made for various aspects of the present application with reference to the accompanying drawings. It should be understood that these detailed descriptions are only descriptions of the embodiments of the present application and do not limit the scope of the present application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0015] It should be noted that in this specification, the expressions such as first, second, third, etc. are only used to distinguish one feature from another feature and do not represent any limitation on the feature. Therefore, without departing from the teachings of the present invention, the first lens discussed below may also be referred to as the second lens or the third lens.

[0016] In the accompanying drawings, for the sake of convenience of illustration, the thickness, size and shape of the lens have been slightly exaggerated. Specifically, the shapes of the spherical or aspherical surfaces shown in the accompanying drawings are shown by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to the spherical or aspherical shapes shown in the accompanying drawings. The accompanying drawings are only examples and are not drawn strictly to scale.

[0017] In this article, the paraxial region refers to the 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 to be photographed is called the object side surface of the lens, and the surface of each lens closest to the imaging surface is called the image side surface of the lens.

[0018] Unless otherwise defined, all terms (including technical terms and scientific terms) used in this article have the same meaning as the ordinary understanding of those of ordinary skill in the art to which the present application belongs. It should also be understood that terms (such as those defined in a common dictionary) should be interpreted as having a meaning consistent with their meaning in the context of the related art and will not be interpreted in an idealized or overly formal sense unless clearly defined as such in this article.

[0019] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The following will describe the present application in detail with reference to the drawings and in combination with the embodiments.

[0020] The high-magnification magnifying glass lens provided by the embodiment of the present invention is sequentially provided with 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.

[0021] In this embodiment, the first lens may have a positive optical power, its object side surface is convex near the optical axis, and its image side surface is concave; the second lens may have a positive optical power, its object side surface is convex near the optical axis, and its image side surface is convex; the third lens may have a positive optical power, its object side surface is convex, and its image side surface is convex.

[0022] In this embodiment, the high-magnification magnifying glass lens may further include a diaphragm, and the diaphragm may 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 image.

[0023] In this 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 satisfying the above conditions and reasonably setting the focal length relationship of the last two lenses, the light can be diverged to a certain extent and the aberration can be effectively corrected, which is beneficial to realizing the large target surface imaging of the lens. At the same time, the system has a longer focal length, meeting the performance characteristics of long focal length and large target surface.

[0024] In this 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 satisfying the above conditions and reasonably setting the meniscus shape of the first lens, as much light as possible can enter the system, enabling the lens to have a wider observation range.

[0025] In this embodiment, the effective focal length f of the high-magnification magnifying glass lens and the focal length f2 of the second lens satisfy: -2.8 < f2 / f < -2.5. The curvature radius R3 of the object side surface of the second lens and the curvature radius R4 of the image side surface of the second lens satisfy: -0.21 < R3 / R4 < -0.17. By satisfying the above conditions, the degree of light convergence can be slowed down, which is beneficial to avoiding excessive light deflection caused by the overly concentrated optical power of the first lens and reducing the difficulty of aberration correction.

[0026] In this embodiment, the effective focal length f of the high-magnification magnifying glass lens and the focal length f3 of the third lens satisfy: -2 < f3 / f < -1.5; the image-side curvature radius R6 of the third lens and the effective focal length f of the optical lens satisfy: 3 < R6 / f < 5; the object-side curvature radius R5 of the third lens and the image-side curvature radius R6 of the third lens satisfy: -0.35 < R5 / R6 < -0.28. Meeting the above conditions is conducive to further convergence of light, enabling the diverging light to smoothly enter the rear optical system and better achieving high-quality imaging of the lens.

[0027] In this embodiment, the high-magnification magnifying glass lens is composed of three lenses, and the specific parameters are as follows: First lens (L1): focal length f1 = 25.2019 mm, object-side curvature radius R1 = 9.9036 mm, image-side curvature radius R2 = 43.8198 mm, lens thickness T1 = 3.34 mm; Second lens (L2): focal length f2 = 21.8585 mm, object-side curvature radius R3 = 12.5682 mm, image-side curvature radius R4 = -67.3474 mm, lens thickness T2 = 3.55 mm; Third lens (L3): focal length f3 = 15.6207 mm, object-side curvature radius R5 = 9.7150 mm, image-side curvature radius R6 = -33.1636 mm, lens thickness T3 = 2.84 mm; The effective focal length f of the optical lens = -8.3276 mm, and the total thickness ∑T = 9.73 mm; Through the above parameter design, the relational expressions such as the focal length ratio, curvature radius ratio, and thickness ratio described in the claims are satisfied, and a magnification ratio of more than 30 times can be achieved, and a clear imaging effect can be provided. At the same time, during the manufacturing process, the manufacturing tolerances of each lens are strictly controlled to ensure the stability and consistency of the imaging quality of the high-magnification magnifying glass lens.

[0028] The following table is the lens data table of the embodiment: Table 1 Lens Data of High-Magnification Magnifying Glass Lens Surface Number Surface Type Radius of Curvature / (mm) Thickness / (mm) Material (Refractive Index: Abbe Number) Object Surface Spherical Surface Infinity -250 S1 Spherical Surface Infinity 13.5 S2 Aspherical Surface 9.9036 3.34 1.50：57.18 S3 Aspherical Surface 43.8198 6.8364 S4 Aspherical Surface 12.5682 3.55 1.50：57.18 S5 Aspherical Surface -67.3474 50 S6 Aspherical Surface 9.7150 2.84 1.50：57.18 S7 Aspherical Surface -33.1636 0.55 Aperture Stop Spherical Surface Infinity 1 S9 Spherical Surface Infinity 21.0385 Image Surface Spherical Surface Infinity 0 Table 2 Aspherical Lens Surface Coefficients of High-Magnification Magnifying Glass Lens

[0029] What is described in this specification only represents the preferred method of the embodiment and does not limit the inventive concept and design technology thereof. As long as it does not exceed the inventive concept and design technology of the present invention, it should fall within the protection scope of the present invention.

Claims

1. A high magnification magnifying glass 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 surface: The first lens (L1) has a positive focal power. Its object side surface is convex near the optical axis, and its image side surface is concave. The second lens (L2) has a positive focal power. Its object side surface is convex near the optical axis, and its image side surface is convex. The third lens (L3) has a positive focal power. Its object side surface is convex, and its image side surface is convex. Among them, 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 glass lens according to claim 1, wherein The effective focal length f of the high-magnification magnifying glass lens, the effective focal length f of the high-magnification magnifying glass lens and the focal lengths f1 of the first lens, f2 of the second lens, and f3 of the third lens respectively satisfy the following relational expressions: -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 glass lens according to claim 1, characterized in that, 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, the curvature radius R3 of the object side surface of the second lens and the curvature radius R4 of the image side surface of the second lens, and the curvature radius R5 of the object side surface of the third lens and the curvature radius R6 of the image side surface of the third lens respectively satisfy the following relational expressions: 0.2 < R1 / R2 < 0.3; -0.21 < R3 / R4 < -0.17; -0.35 < R5 / R6 < -0.

28.

4. The high magnification magnifying glass lens according to claim 1, characterized in that, The high-magnification magnifying glass lens satisfies the following relational expression: 0.32 < T1 / ∑T < 0.36; 0.34 < T2 / ∑T < 0.38; 0.27 < T3 / ∑T < 0.31; Among them, ∑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 glass lens according to claim 1, characterized in that, The magnification of the high-magnification magnifying glass lens > 30 times, and it can provide a clear imaging effect. At the same time, the manufacturing tolerances of each lens of the high-magnification magnifying glass lens are all controlled within a preset range to ensure the stability and consistency of the imaging quality of the high-magnification magnifying glass lens.

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