Microobjective for mineral detection

Abstract

The utility model relates to a microobjective for mineral detection, which comprises a lens cone and an optical structure arranged in the lens cone, the optical structure comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a protective window sheet which are sequentially arranged from an image plane to an object plane along an optical axis, and the protective window sheet is made of sapphire. The first lens and the second lens form a first balsaming lens group, and the third lens and the fourth lens form a second balsaming lens group; the first lens is a meniscus lens, the second lens is a biconvex lens, the third lens is a biconcave lens, the fourth lens is a biconvex lens, and the fifth lens is a plano-convex lens. According to the utility model, the design is reasonable, the optical total length of 400mm can be realized, the particle diameter below 1mu m can be distinguished, the detection requirements of mineral solution are met, and the sapphire protection window with high hardness is additionally arranged at the front end to adapt to a complex and severe solution environment so as to prevent the mineral particles from being scratched and cracked.

Description

TECHNICAL FIELD

[0001] The utility model relates to a mineral detection's microscope objective. BACKGROUND

[0002] Microscopes are widely used in biological detection and industrial measurement detection fields, and have high resolution and high magnification, but in the mineral detection industry, it is required to detect the composition of mineral solution and the size of mineral particles, and the particle diameter and number in the range of 300um-3um need to be distinguished, therefore, the objective lens of the microscope needs to have high magnification and resolution. Since the mineral solution has a long depth and a harsh working environment, the optical total length of the microscope objective lens on the market is generally between 160mm-200mm, which is difficult to meet the requirement of optical total length of 350mm-400mm or more for mineral detection, and is not suitable for complex and harsh use environment, and the industrial endoscope capable of meeting the environmental use requirement cannot detect fine mineral particles due to insufficient magnification. UTILITY MODEL CONTENT

[0003] The utility model makes improvement in view of the above prior art problem, that is, the technical problem to be solved by the utility model is to provide a mineral detection's microscope objective.

[0004] In order to realize the above purpose, the utility model adopts the technical scheme of: a mineral detection's microscope objective, including a lens barrel, an optical structure arranged in the lens barrel, the optical structure including first lens, second lens, third lens, fourth lens, fifth lens and protective window piece arranged in sequence along the optical axis from the image surface to the object surface, the first lens and the second lens constitute a first cemented lens group, and the third lens and the fourth lens constitute a second cemented lens group.

[0005] Further, the first lens is a meniscus lens, the second lens is a double convex lens, the third lens is a double concave lens, the fourth lens is a double convex lens, and the fifth lens is a plano-convex lens.

[0006] Further, the distance L of the microscope objective from the object surface to the image surface is greater than or equal to 400mm, the NA value of the microscope objective is greater than 0.25, and the diameter of the microscope objective is less than 18mm.

[0007] Further, the focal length f of the microscope objective ranges from 25mm to 35mm, the magnification y ranges from 8 to 16, and the ratio between the focal length f and the magnification y is between 1.5 and 4.

[0008] Further, the ratio between the focal length f of the microscope objective and the distance L from the object surface to the image surface is between 10 and 18.

[0009] Further, the focal length f1 of the first cemented lens group is positive, and the focal length range is 20mm < f1 < 60mm.

[0010] Further, the focal length f2 of the second cemented lens group is negative, and the absolute value range of the focal length is 120mm < |f2| < 160mm, and the ratio of the focal length f1 of the first cemented lens group is 3 < f2 / f1 < 4.

[0011] Further, the focal length f3 of the fifth lens is positive, and the focal length range is 15mm < f3 < 30mm, and the ratio of the focal length f2 of the second cemented lens group is 4 < f2 / f3 < 8.

[0012] Further, the protective window sheet is a flat sheet, and the material is sapphire.

[0013] Further, the illumination structure further comprises a fiber inner tube, a fiber outer tube, a fiber interface, a shell, a chip fixing plate and a fiber, the fiber outer tube is fixed at one end of the shell, the fiber inner tube is coaxially arranged in the fiber outer tube, the chip fixing plate is arranged in the shell, the chip fixing plate is used for fixing a sensor chip, and one end of the chip fixing plate is provided with a groove for fixing the fiber inner tube; the fiber is arranged between the fiber inner tube and the fiber outer tube, and the side of the shell is provided with the fiber interface corresponding to the position of the fiber; and the lens barrel is arranged in the end of the fiber inner tube away from the shell.

[0014] Compared with the prior art, the utility model has the following effects: the utility model discloses reasonable in design, can realize 400mm optical total length, can distinguish below 1um particle diameter, is suitable for mineral solution detection demand, and through increasing the sapphire protective window sheet of high hardness at the front end, adapts complex bad solution environment to prevent mineral particle scratch and crack, and adopts microscope front end fiber illumination to be suitable for mineral solution detection environment. BRIEF DESCRIPTION OF DRAWINGS

[0015] Fig. 1 It is the optical structure schematic diagram of the utility model embodiment;

[0016] Fig. 2 It is the optical path schematic diagram of the utility model embodiment;

[0017] Fig. 3 It is the structure schematic diagram of the utility model embodiment.

[0018] In the drawing:

[0019] 1-first lens;2-second lens;3-third lens;4-fourth lens;5-fifth lens;6-protective window sheet;7-lens barrel;8-spacer;9-fiber inner tube;10-fiber outer tube;11-fiber interface;12-shell;13-chip fixing plate;14-fiber;15-optical structure. Detailed implementation mode:

[0020] The present utility model will be further described in detail below in conjunction with the accompanying drawings and specific implementation modes.

[0021] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present utility model, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present utility model.

[0022] As Figs. 1-3 shown, a microscopic objective lens for mineral detection of the present utility model is used to solve the problems that the optical total length of the existing microscope objective lens cannot meet the requirements of mineral detection and the existing microscope illumination method is not applicable. It can achieve an optical total length of 400 mm and adopts fiber optic illumination at the front end of the microscope to be applicable to the mineral solution detection environment, and specifically includes a lens barrel 7 and an optical structure 15 arranged in the lens barrel 7. The optical structure 15 includes a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, a fifth lens 5, and a protective window pane 6 arranged in sequence from the image plane to the object plane along the optical axis. The first lens 1 and the second lens 2 form a first cemented lens group, the third lens 3 and the fourth lens 4 form a second cemented lens group, and a spacer 8 is arranged between the fourth lens 4 and the fifth lens 5. The first and second cemented lens groups play a major role in achromatism correction. The fifth lens converges the light rays emitted from the object plane, and the protective window pane is used to protect the microscope from being scratched.

[0023] In this embodiment, the first lens 1 is a meniscus lens, the second lens 2 is a biconvex lens, the third lens 3 is a biconcave lens, the fourth lens 4 is a biconvex lens, and the fifth lens 5 is a plano-convex lens.

[0024] In this embodiment, the distance L from the object plane to the image plane of the microscopic objective lens is greater than or equal to 400 mm, the NA value of the microscopic objective lens is greater than 0.25, and the diameter of the microscopic objective lens is <18 mm. Preferably, the NA of the microscope = 0.28, and the diameter of the microscope = 17.6 mm.

[0025] In this embodiment, the focal length f of the microscopic objective lens ranges from 25 mm < f < 35 mm, the magnification y ranges from 8 < y < 16, and the ratio between the focal length f and the magnification y is 1.5 < f / y < 4. Preferably, the focal length f of the microscope = 29.16 mm, the magnification y = 12, and the ratio f / y between the focal length f and the magnification y = 2.43.

[0026] In this embodiment, the ratio between the focal length f of the objective lens and the distance L from the object plane to the image plane is: 10 < L / f1 < 18. Preferably, L / f1 = 13.7.

[0027] In this embodiment, the focal length f1 of the first cemented lens group is positive, and the focal length range is 20mm < f1 < 60mm. Preferably, f1 = 41.58mm.

[0028] In this embodiment, the focal length f2 of the second cemented lens group is negative, and the absolute value of the focal length range is 120mm < |f2| < 160mm, and the ratio of the focal length f1 of the first cemented lens group is 3 < f2 / f1 < 4. Preferably, f2 = -136.48mm, and the ratio of the focal length f1 of the first cemented lens group is f2 / f1 = 3.28.

[0029] In this embodiment, the focal length f3 of the fifth lens 5 is positive, and the focal length range is 15mm < f3 < 30mm, and the ratio of the second cemented lens group f2 is 4 < f2 / f3 < 8. Preferably, f3 = 21.96mm, and the ratio of the second cemented lens group f2 is f2 / f3 = 6.21.

[0030] In this embodiment, the protective window sheet is a flat sheet, and the material is sapphire. The sapphire protective window sheet is used to protect the microscope from scratches and adapt to more complex mineral solution environments.

[0031] In this embodiment, it also includes an illumination structure, which includes a fiber inner tube 9, a fiber outer tube 10, a fiber interface 11, a shell 12, a chip fixing plate 13, and a fiber 14. The fiber outer tube 10 is fixed at the front end of the shell 12, the fiber inner tube 9 is coaxially arranged inside the fiber outer tube 10, the fiber inner tube 9 extends into the shell 12, the chip fixing plate 13 is arranged inside the shell 12, the chip fixing plate 13 is used to fix the sensor chip, and the front end of the chip fixing plate 13 is provided with a groove for fixing the fiber inner tube 9; the fiber 14 is arranged between the fiber inner tube 9 and the fiber outer tube 10, the circumferential side of the shell 12 is provided with a fiber interface 11 corresponding to the position of the fiber, and the fiber interface 11 is connected with the fiber 14 corresponding in position; the lens barrel 7 is arranged inside the end of the fiber inner tube 9 away from the shell 12 (i.e. the front end of the fiber inner tube), that is, illumination is formed at the front end. The illumination structure provides front-end illumination for the microscope, and provides a suitable illumination mode at the position closest to the measured mineral particles.

[0032] The optical element parameters of each lens are as follows: (r1 refers to the surface curvature radius along the image plane direction of the light path, r2 refers to the surface curvature radius along the object plane direction of the light path, and D refers to the central thickness. Unit: mm)

[0033] First lens r1 = 28.823 r2 = 11.746 Material: H-ZF52 D = 27.88

[0034] Second lens r1 = 11.746 r2 = -55.127 Material: H-ZK9B D = 8.3

[0035] Third lens r1 = -15.256 r2 = 39.436 Material: H-ZF7LA D = 5.66

[0036] Fourth lens r1 = 39.436 r2 = -18.754 Material: H-LAK51A D = 5.648

[0037] Fifth lens r1 = 19.476 r2 = ∞ Material: H-ZF52A D = 22.913

[0038] Protective window piece r1 = ∞ r2 = ∞ Material: sapphire D = 1.

[0039] The utility model discloses an optical total length is greater than 400mm, and the magnification is greater than 10 times, can distinguish the optical microscopic objective lens of particle diameter 1um below, is suitable for mineral solution detection demand, and through the high hardness sapphire protective window piece of increasing in front end, adapts complex bad solution environment to prevent mineral particle scratch and crack. The external illumination effect of turbid mineral solution is poor, therefore the utility model discloses a fiber illumination structure, can realize detection and illumination integration, and the illumination position is located in the side of microscope, is close to the measured object, and the illumination effect is good.

[0040] If the utility model discloses or involves the mutual fixed connection of parts or structural members, then, except another statement, fixed connection can be understood as: detachable fixed connection (for example using bolt or screw connection), also can be understood as: the fixed connection of undetachable (for example riveting, welding), of course, the mutual fixed connection can also be replaced by integral structure (for example using casting process integral forming to manufacture) (obviously cannot adopt integral forming process except).

[0041] In addition, the terms used to represent the position relationship or shape in any of the technical solutions disclosed in the utility model above include the approximate, similar or close state or shape, except for another statement.

[0042] Any component provided by the utility model can be assembled by multiple individual components, or can be an individual component manufactured by integral forming process.

[0043] 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, all of them should be covered in the technical solution range of the present application claimed.

Claims

1. A mineral detecting microscope, characterized by: The microscope objective comprises a lens barrel, an optical structure arranged in the lens barrel, the optical structure comprising a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a protective window arranged in sequence from an image plane to an object plane along an optical axis, the first lens and the second lens forming a first cemented lens group, and the third lens and the fourth lens forming a second cemented lens group.

2. A microscope objective for mineral detection according to claim 1, characterized in that: The first lens is a meniscus lens, the second lens is a double convex lens, the third lens is a double concave lens, the fourth lens is a double convex lens, and the fifth lens is a plano-convex lens.

3. A mineral detecting microscope objective according to claim 1, characterized in that: The distance L from the object plane to the image plane of the microscope objective is greater than or equal to 400 mm, the NA value of the microscope objective is greater than 0.25, and the diameter of the microscope objective is less than 18 mm.

4. A mineral detecting microscope objective according to claim 1, characterized in that: The focal length f of the microscope objective ranges from 25 mm to 35 mm, the magnification y ranges from 8 to 16, and the ratio between the focal length f and the magnification y ranges from 1.5 to 4.

5. A mineral detecting microscope objective according to claim 1, characterized in that: The ratio between the focal length f of the microscope objective and the distance L from the object plane to the image plane is 10 < L / f1 < 18.

6. A mineral detecting microscope objective according to claim 1, characterized in that: The focal length f1 of the first cemented lens group is positive, and the focal length ranges from 20 mm to 60 mm.

7. A mineral detecting microscope objective according to claim 1, characterized in that: The focal length f2 of the second cemented lens group is negative, and the absolute value of the focal length ranges from 120 mm to 160 mm, and the ratio between the focal length f1 of the first cemented lens group and the focal length f2 of the second cemented lens group is 3 < f2 / f1 < 4.

8. A mineral detecting microscope objective according to claim 1, characterized in that: The focal length f3 of the fifth lens is positive, and the focal length ranges from 15 mm to 30 mm, and the ratio between the focal length f2 of the second cemented lens group and the focal length f3 of the fifth lens is 4 < f2 / f3 < 8.

9. A mineral detecting microscope objective according to claim 1, characterized in that: The protective window is a flat piece, and the material is sapphire.

10. A mineral detecting microscope objective according to claim 1, characterized in that: The illumination structure comprises an optical fiber inner tube, an optical fiber outer tube, an optical fiber interface, a housing, a chip fixing plate and an optical fiber, the optical fiber outer tube is fixed to one end of the housing, the optical fiber inner tube is coaxially arranged in the optical fiber outer tube, the chip fixing plate is arranged in the housing, the chip fixing plate is used for fixing a sensor chip, and one end of the chip fixing plate is provided with a groove for fixing the optical fiber inner tube; the optical fiber is arranged between the optical fiber inner tube and the optical fiber outer tube, and the side of the housing is provided with an optical fiber interface corresponding to the position of the optical fiber; and the lens barrel is arranged in the housing.

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