High-resolution optical system supporting close-range imaging

Abstract

The utility model provides a high resolution optical system supporting close range imaging. The optical system is composed of a front group lens, an iris diaphragm, a rear group lens and an image plane group which are arranged along the direction of an optical path, and the front group lens is composed of a first lens, a second lens, a third lens and a fourth lens which are arranged along the direction of the optical path. The rear lens group is composed of a fifth lens, a sixth lens and a seventh lens which are arranged along the light path direction. The image plane group is a flat lens. According to the utility model, the design is reasonable, the optical system is composed of seven five-group all-glass spherical lenses, the seven lenses and the diaphragm move back and forth along the direction of the optical axis at the same time to realize whole-group movable focusing, the close-up distance can reach 150mm, and the surfaces of the seven five-group all-glass spherical lenses are all provided with antireflection films, so that the reflection of light on the surfaces of the lenses is reduced, and the focusing effect is improved. The light loss is effectively avoided, and the light transmittance is improved, so that the imaging quality is improved, and the shot picture is clearer and finer.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of high-resolution optical systems of supporting close-range imaging. BACKGROUND

[0002] At present, enterprises have increasing demand for efficient and accurate marking technology, and laser marking machines have been widely used in many fields, especially in the semiconductor industry, electronics industry, packaging industry, etc. Secondly, with the continuous progress of laser technology and the increasing demand for intelligentization, laser marking machines begin to introduce automated visual recognition systems, which enable machines to automatically acquire, process images and perform pattern recognition. Not only can it achieve high-quality marking, but also can perform real-time quality detection, significantly improving production efficiency and product quality.

[0003] In the future, with the continuous progress of technology, the marked products will be smaller and smaller, and the precision requirements will be higher and higher. For example, in IC technology in microelectronic technology, the integration is getting denser, the volume is getting smaller, and the precision is getting higher. The application of visual laser marking machines in these fields needs to meet the higher precision and closer object distance shooting requirements. Therefore, it is meaningful to design a high-resolution optical system that supports close-range shooting to provide higher precision and closer object distance visual marking solutions for various industries. SUMMARY

[0004] Therefore, the purpose of the utility model is to overcome the shortcomings of the prior art and provide a high-resolution optical system that supports close-range imaging.

[0005] The utility model adopts the following scheme to realize: a kind of high-resolution optical system that supports close-range imaging: the optical system is formed by front group lens, variable diaphragm, rear group lens and image plane group arranged along the direction of light path, the front group lens is formed by first lens, second lens, third lens and fourth lens arranged along the direction of light path, the rear group lens is formed by fifth lens, sixth lens and seventh lens arranged along the direction of light path, and the image plane group is flat lens.

[0006] Further, the first lens is a meniscus lens, the object side is convex, and the image side is concave. The second lens is a meniscus lens, the object side is concave, and the image side is convex. The third lens is a double convex lens. The fourth lens is a double concave lens. The fifth lens is a double concave lens. The sixth lens is a double convex lens. The seventh lens is a double convex lens.

[0007] Further, the third lens and the fourth lens are bonded to form a first cemented lens group, and the fifth lens and the sixth lens are bonded to form a second cemented lens group.

[0008] Further, the first lens, the fourth lens, and the fifth lens have negative refractive powers; the second lens, the third lens, the sixth lens, and the seventh lens have positive refractive powers; the first cemented lens group has a positive refractive power; and the second cemented lens group has a negative refractive power.

[0009] Further, the front group of lenses has a positive total refractive power, and the rear group of lenses has a positive total refractive power.

[0010] Further, the total focal length f of the optical system, the focal lengths f1, f2, f3, f4, f5, f6, and f7 of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens, respectively, satisfy the following relationships: 1.1 < |f1 / f| < 1.73, 3.66 < |f2 / f| < 6.47, 1.07 < |f3 / f| < 2.03, 4.97 < |f4 / f| < 9.14, 0.28 < |f5 / f| < 0.50, 0.67 < |f6 / f| < 1.16, and 0.77 < |f7 / f| < 1.05.

[0011] Further, the first lens has a refractive index n1 and an Abbe number V1, which satisfy 1.80 < n1 < 2.05 and 45.5 < V1 < 48.5; the second lens has a refractive index n2 and an Abbe number V2, which satisfy 1.65 < n2 < 1.95 and 22.0 < V2 < 24.5; the third lens has a refractive index n3 and an Abbe number V3, which satisfy 1.57 < n3 < 1.62 and 62.0 < V3 < 70.5; the fourth lens has a refractive index n4 and an Abbe number V4, which satisfy 1.47 < n4 < 1.49 and 67.5 < V4 < 75.0; the fifth lens has a refractive index n5 and an Abbe number V5, which satisfy 1.80 < n5 < 2.10 and 31.5 < V5 < 34.0; the sixth lens has a refractive index n6 and an Abbe number V6, which satisfy 1.55 < n6 < 1.65 and 65.5 < V6 < 74.0; and the seventh lens has a refractive index n7 and an Abbe number V7, which satisfy 1.70 < n7 < 2.10 and 41.5 < V7 < 44.5.

[0012] Further, the air gap between the first lens and the second lens is 3.73 mm; the air gap between the second lens and the first cemented lens group is 9.68 mm; the air gap between the front group of lenses and the variable diaphragm is 3.91 mm; the air gap between the variable diaphragm and the rear group of lenses is 1.03 mm; the air gap between the second cemented lens and the seventh lens is 0.1 mm; the air gap between the rear group of lenses and the flat plate lens is 12.12-12.55 mm; and the air gap between the flat plate lens and the imaging surface is 0.3 mm.

[0013] Further, the third lens is made of crown glass, the fourth lens is made of light flint glass, the fifth lens is made of heavy flint glass, and the sixth lens is made of heavy phosphor crown glass.

[0014] Further, the optical system has f=8mm, relative aperture: F / #=3.5, target surface size≤φ9.4mm, and working wavelength: F.d.C.

[0015] Compared with the prior art, the utility model have following beneficial effect: reasonable in design, optical system is by seven piece five group full glass spherical lens composition, through seven piece lens and diaphragm simultaneously along the optical axis direction front and back movement realizes whole group mobile type focusing, its near camera distance can reach 150mm, seven piece five group full glass spherical lens's face all adopts antireflection film, reduces the reflection of light on the lens surface, effectively avoids light loss, improves the transmittance of light, thereby improves the imaging quality, makes the photo more clear and delicate. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 It is the embodiment structure schematic view of the utility model;

[0017] Figure 2 It is the MTF curve graph (150mm object distance) of the utility model;

[0018] Figure 3 It is the MTF curve graph (300mm object distance) of the utility model;

[0019] Figure 4 It is the MTF curve graph (600mm object distance) of the utility model;

[0020] Figure 5 It is the MTF curve graph (1000mm object distance) of the utility model;

[0021] Figure 6 It is the MTF curve graph (infinite object distance) of the utility model.

[0022] In the drawing: A-first lens;B-second lens;C-third lens;D-fourth lens;E-fifth lens;F-sixth lens;G-seventh lens;H-flat plate lens;I-variable diaphragm;H1-first cemented lens group;H2-second cemented lens group. DETAILED DESCRIPTION

[0023] The utility model will be further described below in combination with the drawings and examples.

[0024] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of this application. Unless otherwise specified, all 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 pertains.

[0025] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0026] like Figure 1 As shown, a high-resolution optical system supporting close-range imaging is provided: the optical system consists of a front lens group, a variable aperture I, a rear lens group, and an image plane group arranged along the optical path direction. The front lens group consists of a first lens A, a second lens B, a third lens C, and a fourth lens D arranged along the optical path direction. The rear lens group consists of a fifth lens E, a sixth lens F, and a seventh lens G arranged along the optical path direction. The image plane group is a flat plate lens H.

[0027] In this embodiment, the first lens is a meniscus lens with a convex surface on the object side and a concave surface on the image side; the second lens is a meniscus lens with a concave surface on the object side and a convex surface on the image side; the third lens is a biconvex lens; the fourth lens is a biconcave lens; the fifth lens is a biconcave lens; the sixth lens is a biconvex lens; and the seventh lens is a biconvex lens.

[0028] In this embodiment, the third lens and the fourth lens are bonded together to form a first cemented lens group H1, and the fifth lens and the sixth lens are bonded together to form a second cemented lens group H2.

[0029] In this embodiment, the optical power of the first lens, the fourth lens, and the fifth lens is negative; the optical power of the second lens, the third lens, the sixth lens, and the seventh lens is positive; the optical power of the first cemented lens group is positive; and the optical power of the second cemented lens group is negative.

[0030] In this embodiment, the total optical power of the front lens group is positive, and the total optical power of the rear lens group is positive.

[0031] In the embodiment, the total focal length f of the optical system, the focal lengths of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens are f1, f2, f3, f4, f5, f6 and f7 respectively, and f and f1, f2, f3, f4, f5, f6 and f7 satisfy the following relationships: 1.1<|f1 / f|<1.73, 3.66<|f2 / f|<6.47, 1.07<|f3 / f|<2.03, 4.97<|f4 / f|<9.14, 0.28<|f5 / f|<0.50, 0.67<|f6 / f|<1.16, and 0.77<|f7 / f|<1.05.

[0032] In the embodiment, the refractive index of the first lens is n1, and the Abbe number is V1, satisfying 1.80

[0033] In the embodiment, the air gap between the first lens and the second lens is 3.73mm; the air gap between the second lens and the first cemented lens group is 9.68mm; the air gap between the front group of lenses and the variable diaphragm is 3.91mm; the air gap between the variable diaphragm and the rear group of lenses is 1.03mm; the air gap between the second cemented lens and the seventh lens is 0.1mm; the air gap between the rear group of lenses and the flat plate lens is 12.12-12.55mm; and the air gap between the flat plate lens and the imaging surface is 0.3mm.

[0034] In the embodiment, the third lens is made of low refractive index and achromatic crown glass, the fourth lens is made of high refractive index, high light transmittance and low cost light flint glass, the first cemented lens group formed by cementing reduces the reflection of light of different wavelengths on the air gap, reduces glare and reduces chromatic dispersion, and significantly improves the clarity of the shooting picture and the imaging quality of the optical system; the fifth lens is made of heavy flint glass; the sixth lens is made of heavy phosphor crown glass, which ensures the structural strength and coaxiality of the second cemented lens group, effectively improves the assembly coaxiality of the optical system, and ensures the consistency of the optical system.

[0035] In the embodiment, the seven five-group all-glass spherical lenses are all provided with anti-reflection film, which reduces the reflection of light on the lens surface, effectively avoids light loss, improves the transmittance of light, and thus improves the imaging quality and makes the photographed picture clearer and more delicate.

[0036] In the embodiment, the optical system has f=8mm, relative aperture F / #=3.5, target surface size ≤φ9.4mm, and working wavelength F.d.C.

[0037] In the embodiment, the optical system is composed of seven five-group all-glass spherical lenses, and the whole group is moved by moving the seven lenses and the diaphragm along the optical axis direction at the same time, and the close-up distance can reach 150mm. When the object distance is 150mm, the air gap between the rear lens group and the image surface group is 12.55mm; when the object distance is at infinity, the air gap between the rear lens group and the image surface group is 12.12mm.

[0038] In the embodiment, as shown in Figures 2-6 , the optical system MTF curve is shown in Figure 1 , when the object distance is 150mm, MTF≥0.2@180lp / mm and MTF≥0.4@100lp / mm in the figure; as shown in Figure 2 , when the object distance is 300mm, MTF≥0.2@180lp / mm and MTF≥0.4@100lp / mm in the figure; as shown in Figure 3 , when the object distance is 600mm, MTF≥0.2@180lp / mm and MTF≥0.4@100lp / mm in the figure; as shown in Figure 4 , when the object distance is 1000mm, MTF≥0.2@180lp / mm and MTF≥0.4@100lp / mm in the figure; as shown in Figure 5 , when the object distance is at infinity, MTF≥0.2@180lp / mm and MTF≥0.4@100lp / mm in the figure.

[0039] In the embodiment, the parameters of each lens are shown in the following table:

[0040]

[0041] Any of the above technical solutions of the utility model discloses unless otherwise declared, if it discloses numerical range, then the numerical range disclosed is preferred numerical range, and any person skilled in the art should understand that: preferred numerical range is only the numerical value that technical effect is more obvious or representative among many implementable numerical values. Because there are many numerical values, it is impossible to enumerate, therefore, the utility model discloses only partial numerical values to illustrate the technical solutions of the utility model, and the numerical values enumerated above should not constitute the limitation to the protection scope of the utility model.

[0042] If the words such as "first", "second" are used to limit the components in the present document, those skilled in the art should know that: the use of "first", "second" is only for the convenience of distinguishing the components, and the above words have no special meaning unless otherwise declared.

[0043] If the utility model discloses or involves the components or structural members fixedly connected with each other, then, unless otherwise declared, the fixed connection can be understood as: detachably fixed connection (for example, bolt or screw connection), and also can be understood as: non-detachable fixed connection (for example, riveting, welding), of course, the fixed connection with each other can also be replaced by an integral structure (for example, integrally formed by using casting process) (except for obviously adopting integral forming process).

[0044] In addition, the orientation or position relationship indicated by the above technical solutions of the utility model disclosed for indicating the position relationship, for example, "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like is based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the patent, and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, so it cannot be understood as the limitation of the patent, and the shape-related terms used in the above technical solutions of the utility model disclosed, unless otherwise declared, include shapes similar, similar or close to the shapes.

[0045] Any component provided by the utility model can be assembled by a plurality of individual components, or can be an individual component manufactured by integral forming process.

[0046] It should be noted that the above examples are used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the specific embodiments of the present application can be modified or some technical features can be replaced by equivalent ones; without departing from the spirit of the technical solutions of the present application, they should be covered in the technical solution range claimed by the present application.

Claims

1. A high-resolution optical system supporting close-up imaging, characterized by: The optical system is composed of a front group lens, a variable diaphragm, a rear group lens and an image plane group, the front group lens is composed of a first lens, a second lens, a third lens and a fourth lens arranged along the optical path direction, the rear group lens is composed of a fifth lens, a sixth lens and a seventh lens arranged along the optical path direction, and the image plane group is a flat lens.

2. The high resolution optical system of claim 1, wherein: The first lens is a meniscus lens with a convex object side and a concave image side, the second lens is a meniscus lens with a concave object side and a convex image side, the third lens is a double convex lens, the fourth lens is a double concave lens, the fifth lens is a double concave lens, the sixth lens is a double convex lens, and the seventh lens is a double convex lens.

3. The high resolution optical system of claim 1, wherein: The third lens and the fourth lens are bonded to form a first cemented lens group, and the fifth lens and the sixth lens are bonded to form a second cemented lens group.

4. The high resolution optical system of claim 3, wherein: The first lens, the fourth lens and the fifth lens have negative focal power, the second lens, the third lens, the sixth lens and the seventh lens have positive focal power, the first cemented lens group has positive focal power, and the second cemented lens group has negative focal power.

5. The high resolution optical system of claim 1, wherein: The total focal power of the front group lens is positive, and the total focal power of the rear group lens is positive.

6. The high resolution optical system of claim 1, wherein: The total focal length f of the optical system, the focal lengths f1, f2, f3, f4, f5, f6 and f7 of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens satisfy the following relationships: 1.1<|f1 / f|<1.73, 3.66<|f2 / f|<6.47, 1.07<|f3 / f|<2.03, 4.97<|f4 / f|<9.14, 0.28<|f5 / f|<0.50, 0.67<|f6 / f|<1.16 and 0.77<|f7 / f|<1.

05.

7. The high resolution optical system of claim 1, wherein: The first lens has a refractive index n1 and an Abbe number V1, which satisfy 1.80<n1<2.05 and 45.5<V1<48.5; the second lens has a refractive index n2 and an Abbe number V2, which satisfy 1.65<n2<1.95 and 22.0<V2<24.5; the third lens has a refractive index n3 and an Abbe number V3, which satisfy 1.57<n3<1.62 and 62.0<V3<70.5; the fourth lens has a refractive index n4 and an Abbe number V4, which satisfy 1.47<n4<1.49 and 67.5<V4<75.0; the fifth lens has a refractive index n5 and an Abbe number V5, which satisfy 1.80<n5<2.10 and 31.5<V5<34.0; the sixth lens has a refractive index n6 and an Abbe number V6, which satisfy 1.55<n6<1.65 and 65.5<V6<74.0; and the seventh lens has a refractive index n7 and an Abbe number V7, which satisfy 1.70<n7<2.10 and 41.5<V7<44.

5.

8. The high resolution optical system of claim 1, wherein: The air gap between the first lens and the second lens is 3.73mm; the air gap between the second lens and the first cemented lens group is 9.68mm; the air gap between the front group lens and the variable diaphragm is 3.91mm; the air gap between the variable diaphragm and the rear group lens is 1.03mm; the air gap between the second cemented lens and the seventh lens is 0.1mm; the air gap between the rear group lens and the flat plate lens is 12.12-12.55mm; the air gap between the flat plate lens and the imaging surface is 0.3mm.

9. The high resolution optical system of claim 1, wherein: The third lens is made of crown glass, the fourth lens is made of light flint glass; the fifth lens is made of heavy flint glass; the sixth lens is made of heavy phosphor crown glass.

10. The high resolution optical system of claim 1, wherein: The optical system f=8mm, relative aperture: F / #=3.5, target surface size ≤φ9.4mm, working wavelength: F.d.C.

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