Miniaturized high-definition fixed-focus optical system

Abstract

The utility model relates to a miniaturized high-definition fixed-focus optical system. The optical system consists of a front group, a diaphragm, a rear group and an imaging group which are sequentially arranged from left to right along a light incident light path, the front group is composed of a first biconvex lens, a meniscus lens and a biconcave lens which are sequentially arranged from left to right along a light incident light path, and the rear group is composed of a second biconvex lens. The first biconvex lens, the meniscus lens, the biconcave lens and the second biconvex lens are all full-glass spherical lenses. The optical system adopts a whole-group movable focusing method, that is, the front group, the diaphragm and the rear group axially move along the optical axis, and the imaging group is fixed. The optical system is composed of four pieces of full glass, compared with the prior art, the optical system is small in size, simple and convenient, compact in structure and capable of achieving the ultra-wide working distance, and has high-definition resolution and low distortion in the whole working object distance.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of miniaturization high-definition fixed focus optical system, and optical lens technical field is related to. BACKGROUND

[0002] With the market demand growth of screening machine, technical progress and market competition, etc. Positive development trend is shown, and in the future, it will continue to progress in automation, intelligentization. In view of this, it is meaningful to design a small, high-resolution, low-distortion optical system to cooperate with the use scene of the continuously upgraded CCD visual screening machine. UTILITY MODEL CONTENT

[0003] In view of the deficiencies of the prior art, the technical problem to be solved by the utility model is to provide a kind of miniaturization high-definition fixed focus optical system, to cope with the CCD visual screening machine of continuously upgrading, the optical system has high resolution and low distortion in the whole working object distance.

[0004] In order to solve the above technical problems, the technical scheme of the utility model is: a kind of miniaturization high-definition fixed focus optical system, the optical system is sequentially arranged from left to right by front group, diaphragm, rear group, imaging group along the light path of light incidence;The front group is sequentially arranged from left to right by double convex lens one, meniscus lens, double concave lens along the light path of light incidence, the rear group is composed of double convex lens two;Double convex lens one, meniscus lens, double concave lens, double convex lens two are all full glass spherical lens, and the power of double convex lens one is positive, the object side is convex, the image side is convex;The power of meniscus lens is positive, the object side is convex, the image side is concave;The power of double concave lens is negative, the object side is concave, the image side is concave;The power of double convex lens two is positive, the object side is convex, the image side is convex.

[0005] Preferably, the imaging group is sequentially arranged from left to right by plane lens, image along the light path of light incidence.

[0006] Preferably, the center distance between the plane lens and the image is 0.2mm.

[0007] Preferably, the total power of the front group is positive.

[0008] Preferably, the center distance between double convex lens one and meniscus lens is 0.71mm;The center distance between meniscus lens and double concave lens is 1.31mm.

[0009] Preferably, the center distance between the front group and the rear group is 10.5mm;The center distance between the front group and the diaphragm is 2.21mm;The center distance between the diaphragm and the rear group is 8.29mm.

[0010] Preferably, the distance between the center of the rear group and the center of the imaging group is floatingly changed between 15.78mm and 20.15mm; when the object distance is at infinity, the distance between the center of the rear group and the center of the imaging group is 15.78mm; when the object distance is at 300mm, the distance between the center of the rear group and the center of the imaging group is 20.15mm.

[0011] Preferably, the total focal length f of the optical system, the focal length f1 of the first biconvex lens, the focal length f2 of the meniscus lens, the focal length f3 of the biconcave lens and the focal length f4 of the second biconvex lens are set, and the ratio of f1 to f satisfies the relationship: 0.65<|f1 / f|<0.71; the ratio of f2 to f satisfies the relationship: 0.44<|f2 / f|<0.54; the ratio of f3 to f satisfies the relationship: 0.24<|f3 / f|<0.35; and the ratio of f4 to f satisfies the relationship: 1.39<|f4 / f|<1.50.

[0012] Preferably, the refractive index n1 and the Abbe number V1 of the first biconvex lens satisfy the relationship: 1.57≤n1≤1.62, 62.0≤V1≤66.0; the refractive index n2 and the Abbe number V2 of the meniscus lens satisfy the relationship: 1.8≤n2≤2.0, 40.0≤V2≤44.0; the refractive index n3 and the Abbe number V3 of the biconcave lens satisfy the relationship: 1.65≤n3≤1.95, 27.0≤V3≤28.0; and the refractive index n4 and the Abbe number V4 of the second biconvex lens satisfy the relationship: 1.66≤n4≤1.71, 53.0≤V4≤56.0.

[0013] Preferably, the optical system achieves the following technical indexes: target surface specification ≤φ11mm, focal length f=35mm, relative aperture: D / f=1 / 2.8, optical total length ∑<43.5mm, working wavelength: F.d.C (visible).

[0014] Compared with the prior art, the optical system has the following beneficial effects: the optical system is composed of four full-glass lenses, the design process effectively corrects system aberration by reasonably matching lenses with different refractive indexes and Abbe numbers, the structure is small and compact, the arrangement is reasonable and effective, the working distance is super wide, and high resolution and low distortion are achieved in the whole working object distance.

[0015] The utility model will be further explained in detail in combination with the drawings and specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 The utility model embodiment 300mm object distance transfer function curve.

[0017] Figure 2The object distance 800mm transfer function curve diagram of the embodiment of the present utility model.

[0018] Figure 3 The object distance 1500mm transfer function curve diagram of the embodiment of the present utility model.

[0019] Figure 4 The object distance infinite transfer function curve diagram of the embodiment of the present utility model.

[0020] Figure 5 The object distance 300mm relative luminance curve diagram of the embodiment of the present utility model.

[0021] Figure 6 The object distance 800mm relative luminance curve diagram of the embodiment of the present utility model.

[0022] Figure 7 The object distance 1500mm relative luminance curve diagram of the embodiment of the present utility model.

[0023] Figure 8 The object distance infinite relative luminance curve diagram of the embodiment of the present utility model.

[0024] Figure 9 The object distance 300mm distortion curve diagram of the embodiment of the present utility model.

[0025] Figure 10 The object distance 800mm distortion curve diagram of the embodiment of the present utility model.

[0026] Figure 11 The object distance 1500mm distortion curve diagram of the embodiment of the present utility model.

[0027] Figure 12 The object distance infinite distortion curve diagram of the embodiment of the present utility model.

[0028] Figure 13 The optical system diagram of the embodiment of the present utility model.

[0029] In the figure,

[0030] The front group A, diaphragm B, rear group C, imaging group D;

[0031] The biconvex lens one 1, meniscus lens 2, biconcave lens 3, biconvex lens two 4, plane lens 5, image plane 6. DETAILED DESCRIPTION

[0032] The present utility model will be further described below in combination with the drawings and embodiments.

[0033] 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.

[0034] 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.

[0035] like Figures 1-13 As shown, this embodiment provides a miniaturized high-definition fixed-focus optical system. The optical system consists of a front group A, an aperture B, a rear group C, and an imaging group D arranged sequentially from left to right along the incident light path. The front group consists of a biconvex lens 1, a meniscus lens 2, and a biconcave lens 3 arranged sequentially from left to right along the incident light path. The rear group consists of a biconvex lens 4. The biconvex lens 1, meniscus lens, biconcave lens, and biconvex lens 2 are all all-glass spherical lenses. The biconvex lens 1 has a positive optical power, and its object side and image side are both convex. The meniscus lens has a positive optical power, and its object side and image side are both convex. The biconcave lens has a negative optical power, and its object side and image side are both concave. The biconvex lens 2 has a positive optical power, and its object side and image side are both convex.

[0036] The optical system employs a whole-group moving focusing method, where the front group, aperture, and rear group move axially along the optical axis, while the imaging group remains stationary. During the focusing process from the telephoto end to the near-photo end, the front group, aperture, and rear group move along the optical axis from the image plane to the object plane to compensate for the movement.

[0037] This optical system consists of four glass elements. Compared with the prior art, this invention is small and simple, has a compact structure, can achieve an ultra-wide working distance, and has high-definition resolution and low distortion throughout the entire working distance.

[0038] In this embodiment of the invention, the imaging group consists of a planar lens 5 and an image plane 6 arranged sequentially from left to right along the incident light path.

[0039] In this embodiment of the invention, the center distance between the plane lens and the image plane is 0.2 mm.

[0040] In this embodiment of the invention, the total optical power of the front group is positive.

[0041] In the embodiment of the utility model, the center distance of the double convex lens one and the meniscus lens is 0.71mm; the center distance of the meniscus lens and the double concave lens is 1.31mm.

[0042] In the embodiment of the utility model, the center distance of the front group and the rear group is 10.5mm; the center distance of the front group and the diaphragm is 2.21mm; the center distance of the diaphragm and the rear group is 8.29mm.

[0043] In the embodiment of the utility model, the center distance of the rear group and the imaging group is between 15.78~20.15mm and changes floatingly; when the object distance is at infinity, the center distance of the rear group and the imaging group is 15.78mm; when the object distance is at 300mm, the center distance of the rear group and the imaging group is 20.15mm.

[0044] The optical system adopts the change amount of the center distance of the rear group and the imaging group to compensate the change amount of the imaging of the object distance, so as to realize clear imaging.

[0045] In the embodiment of the utility model, the total focal length f of the optical system lens, the focal length f1 of the double convex lens one, the focal length f2 of the meniscus lens, the focal length f3 of the double concave lens and the focal length f4 of the double convex lens two are set, and the ratio of f1 and f satisfies the relationship formula: 0.65<|f1 / f|<0.71; the ratio of f2 and f satisfies the relationship formula: 0.44<|f2 / f|<0.54; the ratio of f3 and f satisfies the relationship formula: 0.24<|f3 / f|<0.35; and the ratio of f4 and f satisfies the relationship formula: 1.39<|f4 / f|<1.50.

[0046] In the embodiment of the utility model, the refractive index n1 of the double convex lens one and the Abbe number V1 satisfy the relationship formula: 1.57≤n1≤1.62, 62.0≤V1≤66.0; the refractive index n2 of the meniscus lens and the Abbe number V2 satisfy the relationship formula: 1.8≤n2≤2.0, 40.0≤V2≤44.0; the refractive index n3 of the double concave lens and the Abbe number V3 satisfy the relationship formula: 1.65≤n3≤1.95, 27.0≤V3≤28.0; and the refractive index n4 of the double convex lens two and the Abbe number V4 satisfy the relationship formula: 1.66≤n4≤1.71, 53.0≤V4≤56.0.

[0047] In the embodiment of the utility model, the optical system double convex lens one selects heavy phosphor crown glass which has good heat resistance, low refractive index and small dispersion, so that the imaging quality of the optical system can be effectively ensured.

[0048] In the embodiment of the utility model, the optical system designs the left curvature radius R8 and the right curvature radius R9 of the lenticular lens as equal, saves the grinding tool development cost, and reduces the optical processing technology and system assembly sensitivity.

[0049] In the embodiment of the utility model, the technical index realized by the optical system is as follows: target surface specification ≤ φ11mm, focal length f=35mm, relative aperture: D / f=1 / 2.8, optical total length ∑<43.5mm, working wavelength: F.d.C (visible).

[0050] The optical system is composed of four full glass lenses, the design process effectively corrects the system aberration by reasonably matching lenses with different refractive indexes and Abbe numbers, makes the structure small and compact, and is reasonably and effectively arranged, thereby realizing an ultra-wide working distance and high definition resolution and low distortion in the whole working distance.

[0051] In the embodiment of the utility model, the optical system transfer function curve diagram is as shown in the figure Figure 1 At 300mm object distance, MTF≥0.2@200lp / mm and MTF≥0.4@125lp / mm in the figure; as shown in the figure Figure 2 At 800mm object distance, MTF≥0.2@200lp / mm and MTF≥0.4@125lp / mm in the figure; as shown in the figure Figure 3 At 1500mm object distance, MTF≥0.2@200lp / mm and MTF≥0.4@125lp / mm in the figure; as shown in the figure Figure 4 At infinite object distance, MTF≥0.2@200lp / mm and MTF≥0.4@125lp / mm in the figure. Thus, the optical system has high definition resolution and can support 2.5μm high resolution pixels in the whole working distance.

[0052] The optical system relative luminance curve diagram is as shown in the figure Figure 5 At 300mm object distance, relative luminance≥90%@5.5mm near-axis image height in the figure; as shown in the figure Figure 6 At 800mm object distance, relative luminance≥90%@5.5mm near-axis image height in the figure; as shown in the figure Figure 7 At 1500mm object distance, relative luminance≥85%@5.5mm near-axis image height in the figure; as shown in the figure Figure 8 At infinite object distance, relative luminance≥85%@5.5mm near-axis image height in the figure. Thus, the optical system has high relative luminance in the whole working distance.

[0053] The optical system distortion curve diagram is as shown in the figure Figure 9 At 300mm object distance, optical distortion is less than -0.2% in the figure; as shown in the figure Figure 10The optical distortion of the figure is less than -0.1% at 600mm object distance; as Figure 11 The optical distortion of the figure is less than 0.1% at 1500mm object distance; as Figure 12 The optical distortion of the figure is less than 0.2% at infinite object distance.

[0054] In the embodiment of the utility model, the parameters of each lens are shown in the following table:

[0055]

[0056] The above is only the preferred embodiment of the utility model, and is not intended to limit the utility model in other forms. Any skilled person in the art can modify or change the above disclosed technology content to equivalent embodiments. However, any simple modification, equivalent change and modification of the above embodiments without departing from the technical solution of the utility model, according to the technical essence of the utility model, still belongs to the protection scope of the technical solution of the utility model.

Claims

1. A miniaturized high-definition fixed-focus optical system characterized by: The optical system is composed of a front group, an aperture, a rear group and an imaging group arranged in sequence from left to right along the light path of light incidence; the front group is composed of a lenticular lens one, a meniscus lens and a biconcave lens arranged in sequence from left to right along the light path of light incidence; the rear group is composed of a lenticular lens two; the lenticular lens one, the meniscus lens, the biconcave lens and the lenticular lens two are all full-glass spherical lenses, and the lenticular lens one has positive focal power, the object plane side is convex, and the image plane side is convex; the meniscus lens has positive focal power, the object plane side is convex, and the image plane side is concave; the biconcave lens has negative focal power, the object plane side is concave, and the image plane side is concave; the lenticular lens two has positive focal power, the object plane side is convex, and the image plane side is convex.

2. The miniaturized high-definition fixed-focus optical system according to claim 1, characterized in that: The imaging group is composed of a plane lens and an image plane arranged in sequence from left to right along the light path of light incidence.

3. The miniaturized high definition fixed focus optical system according to claim 2, characterized in that: The center distance between the plane lens and the image plane is 0.2 mm.

4. The miniaturized high definition fixed focus optical system of claim 1, wherein: The total focal power of the front group is positive.

5. The miniaturized high definition fixed focus optical system of claim 1, wherein: The center distance between the lenticular lens one and the meniscus lens is 0.71 mm; the center distance between the meniscus lens and the biconcave lens is 1.31 mm.

6. The miniaturized high definition fixed focus optical system of claim 1, wherein: The center distance between the front group and the rear group is 10.5 mm; the center distance between the front group and the aperture is 2.21 mm; the center distance between the aperture and the rear group is 8.29 mm.

7. The miniaturized high definition fixed focus optical system of claim 1, wherein: The center distance between the rear group and the imaging group is floating between 15.78-20.15 mm; when the object distance is at infinity, the center distance between the rear group and the imaging group is 15.78 mm; when the object distance is at 300 mm, the center distance between the rear group and the imaging group is 20.15 mm.

8. The miniaturized high definition fixed focus optical system of claim 1, wherein: The total focal length f of the optical system lens, the focal length f1 of the lenticular lens one, the focal length f2 of the meniscus lens, the focal length f3 of the biconcave lens and the focal length f4 of the lenticular lens two are set, and the ratio of f1 to f satisfies the relationship: 0.65<|f1 / f|<0.71; the ratio of f2 to f satisfies the relationship: 0.44<|f2 / f|<0.54; the ratio of f3 to f satisfies the relationship: 0.24<|f3 / f|<0.35; and the ratio of f4 to f satisfies the relationship: 1.39<|f4 / f|<1.

50.

9. The miniaturized high definition fixed focus optical system of claim 1, wherein: The refractive index n1 and the Abbe number V1 of the lenticular lens one satisfy the relationship: 1.57≤n1≤1.62, 62.0≤V1≤66.0; the refractive index n2 and the Abbe number V2 of the meniscus lens satisfy the relationship: 1.8≤n2≤2.0, 40.0≤V2≤44.0; the refractive index n3 and the Abbe number V3 of the biconcave lens satisfy the relationship: 1.65≤n3≤1.95, 27.0≤V3≤28.0; and the refractive index n4 and the Abbe number V4 of the lenticular lens two satisfy the relationship: 1.66≤n4≤1.71, 53.0≤V4≤56.

0.

10. The miniaturized high definition fixed focus optical system of claim 1, wherein: The optical system achieves the following technical indexes: target surface specification ≤φ11mm, focal length f=35mm, relative aperture: D / f=1 / 2.8, optical total length ∑<43.5mm, working wavelength: F.d.C visible light, wherein the wavelength of F light is 486.1nm, the wavelength of d light is 466.8nm, and the wavelength of C light is 656.3nm.

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