Microobjective and imaging equipment

Abstract

The invention provides a microscope objective and an imaging device, and relates to the technical field of optical lenses, and the microscope objective sequentially comprises a first lens group G1, a second lens group G2 and a third lens group G3 from the object side to the image side; the first lens group and the third lens group have negative focal power, and the second lens group has positive focal power. Wherein the second lens group is provided with a group of triplet lenses. According to the technical scheme provided by the invention, through reasonable focal power matching among the first lens group, the second lens group and the third lens group, the microscope lens provided by the invention has the advantages of longer working distance, larger NA, higher resolution and the like compared with an existing microscope lens with the same magnification; glass materials with specific refractive indexes and Abbe numbers are selected for triple gluing, so that visible light and near infrared confocal is realized; the microscope lens provided by the invention can better meet the requirements of increasing diversification and complexity of the microscope lens in the market.

Description

Technical Field

[0001] The present invention relates to the technical field of optical lenses, and in particular to a microscope objective lens and an imaging device. Background Art

[0002] With the continuous expansion of the country's demand and investment in the fields of semiconductors, life sciences, and microscopic detection, many new requirements have been put forward for the performance of microscopes widely used in these fields. For example, in order to avoid the microscope from contacting and damaging the test sample and to leave a safe operating space, the microscope is required to have a longer working distance; in order to capture weak biological fluorescence and increase the amount of light entering, the microscope is required to have a larger numerical aperture; in order to be able to use multiple bands to conduct a full range of observations on the test sample, the microscope is required to be confocal in the visible light band and the near-infrared band.

[0003] Existing microscopes on the market are unable to simultaneously meet the technical requirements of long working distance, large numerical aperture, and confocality in the visible and near-infrared bands, and a solution is urgently needed. Summary of the invention

[0004] In order to make up for the deficiencies of the prior art, the embodiments of the present application propose a microscope objective lens and an imaging device to solve the problems existing in the prior art.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0006] A microscope objective lens and an imaging device, comprising a first lens group, a second lens group, and a third lens group arranged in sequence from the object side to the image side; the first lens group and the third lens group have negative optical power, and the second lens group has positive optical power;

[0007] The first lens group includes a first lens and a second lens arranged in sequence along the optical axis; the first lens is a positive lens, and the second lens is a negative lens;

[0008] The second lens group includes a third lens, a fourth lens, a fifth lens, and a sixth lens arranged in sequence along the optical axis; the third lens, the fifth lens, and the sixth lens are positive lenses, and the fourth lens is a negative lens;

[0009] The third lens group includes a seventh lens, an eighth lens, a ninth lens, and a tenth lens sequentially arranged along the optical axis; the seventh lens and the ninth lens are negative lenses, and the eighth lens and the tenth lens are positive lenses.

[0010] As a further technical solution of the present invention: the first lens is a biconvex lens; the second lens is a biconcave lens.

[0011] As a further technical solution of the present invention: the third lens is a biconvex lens; the fourth lens is a meniscus lens with the convex surface facing the image side; the fifth lens is a meniscus lens with the convex surface facing the image side; the sixth lens is a meniscus lens with the convex surface facing the image side.

[0012] As a further technical solution of the present invention: the seventh lens is a biconcave lens; the eighth lens is a biconvex lens; the ninth lens is a meniscus lens with the convex surface facing the image side; and the tenth lens is a meniscus lens with the convex surface facing the image side.

[0013] As a further technical solution of the present invention: the third lens, the fourth lens and the fifth lens are cemented together to form a triplet lens. The Abbe number of the material of the third lens and the Abbe number of the material of the fifth lens satisfy the following relationship:

[0014] 68<Vd3<72,68<Vd5<72

[0015] The refractive index and Abbe number of the material of the fourth lens respectively satisfy the following relationship:

[0016] 1.60<Nd4<1.62, 43<Vd4<45

[0017] Among them, Vd3 is the Abbe number of the material of the third lens, Vd5 is the Abbe number of the material of the fifth lens, Nd4 is the refractive index of the material of the fourth lens, and Vd4 is the Abbe number of the material of the fourth lens.

[0018] As a further technical solution of the present invention: the focal length of the first lens group and the focal length of the third lens group satisfy the following relationship:

[0019] 1.0<fG3 / fG1<1.3

[0020] The focal length of the second lens group and the overall focal length of the microscope objective lens satisfy the following relationship:

[0021] 0.35<fG2 / f<0.4

[0022] Among them, fG3 is the focal length of the third lens group, fG1 is the focal length of the first lens group, fG2 is the focal length of the second lens group, and f is the overall focal length of the microscope objective lens.

[0023] As a further technical solution of the present invention: the working distance of the microscope objective lens satisfies the following relationship:

[0024] 27mm≤WD≤30mm

[0025] Wherein, WD is the working distance of the microscope objective lens, that is, the distance from the object plane to the vertex of the object side surface of the first lens.

[0026] As a further technical solution of the present invention: the numerical aperture of the microscope objective lens satisfies the following relationship:

[0027] 0.27≤NA≤0.3

[0028] Wherein, NA is the numerical aperture of the microscope objective lens.

[0029] As a further technical solution of the present invention: the focal length of the microscope objective lens satisfies the following relationship:

[0030] 79mm<f<81mm

[0031] Wherein, f is the overall focal length of the microscope objective.

[0032] As a further technical solution of the present invention: the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, the ninth lens, and the tenth lens are all spherical lenses made of glass.

[0033] The present invention also provides an optical imaging device, comprising the microscope objective lens as described above.

[0034] One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:

[0035] Compared with existing microscope lenses of the same magnification, the microscope lens of the present invention has the advantages of longer working distance, larger NA, higher resolution, etc.; by selecting glass materials with specific refractive index and Abbe number for triple bonding, visible light and near-infrared confocality is achieved; the microscope lens of the present invention can better meet the market's increasingly diversified and complex demands for microscope lenses. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 A first structural schematic diagram of an embodiment of a microscope objective lens provided by the present invention;

[0037] Figure 2 A second structural schematic diagram of an embodiment of a microscope objective lens provided by the present invention;

[0038] Figure 3 The MTF diagram of the object plane of the microscope objective provided by the present invention in the visible light band with a wavelength of 435nm to 656nm;

[0039] Figure 4 An optical distortion diagram of the object plane of the microscope objective provided by the present invention in the visible light band with a wavelength of 435nm to 656nm;

[0040] Figure 5The MTF diagram of the object plane of the microscope objective provided by the present invention in the near-infrared light band with a wavelength of 750nm to 1600nm;

[0041] Figure 6 The optical distortion diagram of the object plane of the microscope objective provided by the present invention in the near-infrared light band with a wavelength of 750nm to 1600nm.

[0042] Description of Figure Numbers:

[0043] 100, first lens group; 101, first lens; 102, second lens;

[0044] 200, second lens group; 201, third lens; 202, fourth lens; 203, fifth lens; 204, sixth lens;

[0045] 300, third lens group; 301, seventh lens; 302, eighth lens; 303, ninth lens; 304, tenth lens;

[0046] 400, physical surface;

[0047] 500, Image side exit surface. DETAILED DESCRIPTION

[0048] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0049] The present invention proposes a microscope lens that takes into account the lens requirements of longer working distance, larger numerical aperture, higher resolution, and confocality of visible light band and near-infrared band, so as to meet the market demand for increasingly diversified and complex lenses.

[0050] See also Figure 1 In one embodiment of the present invention, the imaging lens comprises an object plane 400, a first lens group 100, a second lens group 200, a third lens group 300 and an image emission surface 500 which are sequentially arranged from the object side to the image side; the first lens group 100 and the third lens group 300 have negative optical power, and the second lens group 200 has positive optical power;

[0051] The first lens group 100 includes a first lens 101 and a second lens 102 arranged in sequence along the optical axis; the first lens 101 is a positive lens, and the second lens 102 is a negative lens;

[0052] The second lens group 200 includes a third lens 201, a fourth lens 202, a fifth lens 203, and a sixth lens 204 which are sequentially arranged along the optical axis; the third lens 201, the fifth lens 203, and the sixth lens 204 are negative lenses, and the fourth lens 202 is a positive lens;

[0053] The third lens group 300 includes a seventh lens 301, an eighth lens 302, a ninth lens 303, and a tenth lens 304 arranged in sequence along the optical axis; the seventh lens 301 and the ninth lens 303 are negative lenses, and the eighth lens 302 and the tenth lens 303 are positive lenses.

[0054] In this embodiment, a longer working distance is achieved by the first lens group 100 with negative optical power; parallel light output is achieved by the third lens group 300 with negative optical power, that is, the microscope objective is an infinity-corrected microscope objective; a larger numerical aperture is achieved by reasonable optical power matching among the first lens group 100, the second lens group 200, and the third lens group 300; and the confocality of the visible light band and the near-infrared band of the microscope objective is achieved by the three-cemented lens composed of the third lens 201, the fourth lens 202, and the fifth lens 203 located in the second lens group 300 and made of glass materials with specific refractive index and Abbe number.

[0055] More specifically, the negative lens group has the function of diverging light; and the positive lens group has the function of converging light. The diverging effect of the first lens group 100 allows the convergence point of the light to gradually move away from the lens group, thereby achieving a long working distance; the beam shaping effect of the third lens group 300 corrects the residual aberration of the light after passing through the previous two lens groups, so that the divergent light on the object plane becomes parallel light, that is, the objective lens is an infinity-corrected microscope objective lens; the reasonable distribution of optical focal lengths among the first lens group 100, the second lens group 200, and the third lens group 300 achieves a large numerical aperture; at the same time, a large numerical aperture means a higher resolution; the third lens 201, the fourth lens 202, and the fifth lens 203 of the second lens group 200 are three-cemented, and the axial chromatic aberration and the vertical chromatic aberration of light of different wavelengths are corrected, so that the axial chromatic aberration and the vertical chromatic aberration of the wavelength from 435nm to 1700nm are controlled in a good range, and the confocality of the visible light band and the near-infrared light band is achieved.

[0056] It can be seen that the technical solution of the present invention, through the reasonable optical focal length matching between the first lens group 100, the second lens group 200, and the third lens group 300, and the three lenses 201, the fourth lens 202, and the fifth lens 203, which are made of materials with specific refractive indices and Abbe numbers, are triple-bonded, so that the microscope objective lens of the present invention has the advantages of long working distance, large numerical aperture, high resolution, and confocality of the visible light band and the near-infrared band, which can better meet the increasingly diversified and complex market demands for microscope objective lenses.

[0057] Optionally, refer to Figure 1 and Figure 2 , the first lens 101 is a biconvex positive lens; the second lens 102 is a biconcave negative lens.

[0058] Optionally, refer to Figure 1 and Figure 2 The third lens 201 is a double convex positive lens; the fourth lens 202 is a negative meniscus lens, and the convex surface of the fourth lens 202 faces the image side exit surface 500; the fifth lens 203 is a positive meniscus lens, and the convex surface of the fifth lens 203 faces the image side exit surface 500; the sixth lens 204 is a positive meniscus lens, and the convex surface of the sixth lens 204 faces the image side exit surface 500.

[0059] Optionally, refer to Figure 1 and Figure 2 , the seventh lens 301 is a double concave negative lens; the eighth lens 302 is a double convex positive lens; the ninth lens 303 is a meniscus negative lens, and the convex surface of the ninth lens 303 faces the image side exit surface 500; the tenth lens 304 is a meniscus positive lens, and the convex surface of the tenth lens 304 faces the image side exit surface 500.

[0060] The third lens 201 , the fourth lens 202 , and the fifth lens 203 are three-cemented, the seventh lens 301 is glued to the eighth lens 302 , and the ninth lens 303 is glued to the tenth lens 304 .

[0061] Optionally, refer to Figure 1 and Figure 2 The third lens 201, the fourth lens 202, and the fifth lens 203 are cemented to form a triplet lens. The Abbe number of the material of the third lens 201 and the Abbe number of the material of the fifth lens 203 satisfy the following relationship:

[0062] 68<Vd3<72,68<Vd5<72

[0063] The refractive index and Abbe number of the material of the fourth lens 202 respectively satisfy the following relationship:

[0064] 1.60<Nd4<1.62, 43<Vd4<45

[0065] Wherein, Vd3 is the Abbe number of the material of the third lens 201 , Vd5 is the Abbe number of the material of the fifth lens 203 , Nd4 is the refractive index of the material of the fourth lens 202 , and Vd4 is the Abbe number of the material of the fourth lens 202 .

[0066] Optionally, refer to Figure 1 and Figure 2 , the focal length of the first lens group 100 and the focal length of the third lens group 300 satisfy the following relationship:

[0067] 1.0<fG3 / fG1<1.3

[0068] The focal length of the second lens group 200 and the overall focal length of the microscope objective lens satisfy the following relationship:

[0069] 0.35<fG2 / f<0.4

[0070] Wherein, fG3 is the focal length of the third lens group 300, fG1 is the focal length of the first lens group 100, fG2 is the focal length of the second lens group 200, and f is the overall focal length of the microscope objective lens.

[0071] Optionally, refer to Figure 1 and Figure 2 , the working distance of the microscope objective lens satisfies the following relationship:

[0072] 27mm≤WD≤30mm

[0073] Wherein, WD is the working distance of the microscope objective, that is, the distance from the object plane to the vertex of the object side surface of the first lens.

[0074] Optionally, refer to Figure 1 and Figure 2 , the numerical aperture of the microscope objective satisfies the following relationship:

[0075] 0.27≤NA≤0.3

[0076] Wherein, NA is the numerical aperture of the microscope objective lens.

[0077] Optionally, refer to Figure 1 and Figure 2 , the focal length of the microscope objective lens satisfies the following relationship:

[0078] 79mm<f<81mm

[0079] Where f is the overall focal length of the microscope objective.

[0080] Optionally, refer to Figure 1 and Figure 2The first lens 101, the second lens 102, the third lens 201, the fourth lens 202, the fifth lens 203, the sixth lens 204, the seventh lens 205, the eighth lens 301, the ninth lens 302 and the tenth lens 303 are all spherical lenses made of glass.

[0081] Based on the parameter settings and material combinations of each lens group and each lens in the above embodiments, the microscope objective lens not only obtains advantages such as a longer working distance, a larger numerical aperture, and a higher resolution, but also achieves confocality between the visible light band and the near-infrared band, thereby further improving the performance of the microscope objective lens and broadening its application range.

[0082] Reference Figure 2 In a specific embodiment, the parameters of the surface curvature radius, thickness, refractive index, Abbe number, etc. of each lens included in the microscope lens are shown in Table 1. The thickness refers to the distance between each lens surface and the next lens surface; for example, the thickness of S1 refers to the distance between the center of S1 and the center of S2, that is, the center thickness of the first lens 101; the thickness of S2 refers to the distance between the center of S2 and the center of S3, that is, the air thickness between the first lens 101 and the second lens 102.

[0083]

[0084] According to the data in Table 1, the focal length of the microscope objective lens is f=80mm. If it is used in conjunction with a tube lens with a focal length of 200mm, the combined magnification is 2.5x; the object numerical aperture NA=0.30, the working distance WD=30mm, the object circle diameter D=4.6mm, fG1=-111.56, fG2=30, and fG3=-130.94. It can be obtained that Vd3=71.3, Vd5=71.3, Nd4=1.61, Vd4=44.1, fG3 / fG1=1.17, and fG2 / f=0.375; in addition, the lenses used in this embodiment are all glass spherical lenses; the above parameters all meet the requirements. Among them, the third lens 201, the fourth lens 202, and the fifth lens 203 respectively use glass materials with specific Abbe numbers and refractive indices, which can correct the chromatic aberration of the visible light band and the near-infrared light band, and realize the visible light and near-infrared confocal. Based on the above embodiment, the actual test results of the imaging lens are as follows:

[0085] Figure 3 and Figure 5They are respectively the MTF graph (Modul at ion Transfer Function curve graph) of the object plane of the microscope objective lens in the above embodiment in the visible light band with a wavelength of 435nm to 656nm and the MTF graph (Modul at ion Transfer Function curve graph) of the object plane in the near-infrared light band with a wavelength of 750nm to 1600nm. Figure 3 and Figure 6 It can be seen that the MTF curves of the object plane of the microscope objective in the visible light band and the near-infrared light band are close to the diffraction-limited MTF curve, that is, confocality is achieved in the visible light and near-infrared bands.

[0086] Figure 4 and Figure 6 They are respectively the optical distortion diagram of the object plane of the microscope objective lens in the above embodiment in the visible light band with a wavelength of 435nm to 656nm and the optical distortion diagram of the object plane in the near-infrared light band with a wavelength of 750nm to 1600nm. Figure 4 and Figure 6 It can be seen that the optical distortion of the microscope objective is very small, which is 0.0096% in the visible light band and only 0.0018% in the near-infrared light band.

[0087] The present invention also proposes an optical imaging device, which includes a microscope objective lens. The specific structure of the microscope objective lens refers to the above-mentioned embodiment. Since the optical imaging device adopts all the technical solutions of all the above-mentioned embodiments, it at least has all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be described one by one here.

[0088] Among them, the optical imaging device can be a microscope, a projector, a scanner, etc. As long as it uses the microscope objective lens provided by the above embodiments and realizes imaging based on optical imaging technology, it belongs to the optical imaging device described in the present invention.

[0089] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

[0090] In addition, it should be understood that although this specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment have also been appropriately combined to form other implementation modes that are easy for those skilled in the art to understand.

Claims

1. A microscope objective lens and an imaging device, characterized in that: It comprises a first lens group, a second lens group, and a third lens group which are arranged in sequence from the object side to the image side; the first lens group and the third lens group have negative optical power, and the second lens group has positive optical power; The first lens group includes a first lens and a second lens arranged in sequence along the optical axis; the first lens is a positive lens, and the second lens is a negative lens; The second lens group includes a third lens, a fourth lens, a fifth lens, and a sixth lens arranged in sequence along the optical axis; the third lens, the fifth lens, and the sixth lens are positive lenses, and the fourth lens is a negative lens; The third lens group includes a seventh lens, an eighth lens, a ninth lens, and a tenth lens sequentially arranged along the optical axis; the seventh lens and the ninth lens are negative lenses, and the eighth lens and the tenth lens are positive lenses.

2. A microscope objective lens and imaging device according to claim 1, characterized in that: The first lens is a biconvex lens; the second lens is a biconcave lens.

3. A microscope objective lens and imaging device according to claim 1, characterized in that: The third lens is a biconvex lens; the fourth lens is a meniscus lens with the convex surface facing the image side; the fifth lens is a meniscus lens with the convex surface facing the image side; and the sixth lens is a meniscus lens with the convex surface facing the image side.

4. A microscope objective lens and imaging device according to claim 1, characterized in that: The seventh lens is a biconcave lens; the eighth lens is a biconvex lens; the ninth lens is a meniscus lens with its convex surface facing the image side; and the tenth lens is a meniscus lens with its convex surface facing the image side.

5. A microscope objective lens and imaging device according to claim 1, characterized in that: The third lens, the fourth lens, and the fifth lens are cemented together to form a triplet lens; the Abbe number of the material of the third lens and the Abbe number of the material of the fifth lens satisfy the following relationship: 68<Vd3<72,68<Vd5<72 The refractive index and Abbe number of the material of the fourth lens respectively satisfy the following relationship: 1.60<Nd4<1.62, 43<Vd4<45 Among them, Vd3 is the Abbe number of the material of the third lens, Vd5 is the Abbe number of the material of the fifth lens, Nd4 is the refractive index of the material of the fourth lens, and Vd4 is the Abbe number of the material of the fourth lens.

6. A microscope objective lens and imaging device according to claim 1, characterized in that: The focal length of the first lens group and the focal length of the third lens group satisfy the following relationship: 1.0<fG3 / fG1<1.3 The focal length of the second lens group and the overall focal length of the microscope objective lens satisfy the following relationship: 0.35<fG2 / f<0.4 Among them, fG3 is the focal length of the third lens group, fG1 is the focal length of the first lens group, fG2 is the focal length of the second lens group, and f is the overall focal length of the microscope objective lens.

7. A microscope objective lens and imaging device according to claim 1, characterized in that: The working distance of the microscope objective lens satisfies the following relationship: 27mm≤WD≤30mm Wherein, WD is the working distance of the microscope objective lens, that is, the distance from the object plane to the vertex of the object side surface of the first lens; And / or, the numerical aperture of the microscope objective lens satisfies the following relationship: 0.27≤NA≤0.3 Wherein, NA is the numerical aperture of the microscope objective lens; And / or, the focal length of the microscope objective lens satisfies the following relationship: 79mm<f<81mm Wherein, f is the overall focal length of the microscope objective lens; And / or, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, the ninth lens, and the tenth lens are all spherical lenses made of glass.

8. An optical imaging device, characterized in that: Comprising the microscope objective lens as claimed in any one of claims 1 to 7.

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