Internal focusing microscopic optical system

Abstract

The invention discloses an internal focusing microscopic optical system, which consists of an object plane, a first transmission group with positive focal power, a second transmission group with negative focal power and an image plane which are sequentially arranged from an object space to an image space, the first transmission group is composed of a first biconcave lens, a first biconvex lens, a second biconvex lens, a positive meniscus lens, a third biconvex lens and a second biconcave lens which are sequentially arranged from an object side to an image side, the second transmission group is composed of a third biconcave lens, and the first transmission group has the characteristics of high diffraction order resolution, large numerical aperture (NA) 0.3, paraxial magnification (PMAG)-8.9, working wavelength of 630 nm, and wide range of application. And meanwhile, the system has the characteristics of internal focusing function, short conjugate distance and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of microscopic optics, and in particular relates to an internal focusing microscopic optical system. Background Art

[0002] Microscopic optical systems are widely used in scientific research, medical diagnosis, industrial detection and other fields. Microscopes play a vital role in the observation and analysis of tiny objects. With the advancement of technology, people have higher and higher requirements for microscopic optical systems, especially in terms of focus adjustment. Traditional microscope systems often cannot meet the needs of modern scientific research and industrial applications.

[0003] Existing microscope optical systems usually rely on mechanical focusing. Although mechanical focusing is relatively simple, it has low adjustment accuracy and is prone to mechanical wear during frequent focusing, which affects the service life. Especially under the requirements of high-precision and high-frequency focusing, the performance is obviously insufficient.

[0004] In addition, most of the focusing methods of traditional microscope optical systems require external mechanical drive, which makes the system structure more complicated and limits the compactness and flexibility of the microscope system. In some special application scenarios, such as high-resolution imaging, rapid scanning observation, etc., the existing technology cannot effectively meet the needs of fast and precise focusing.

[0005] Therefore, how to design an internal focusing microscopic optical system that can simplify the system structure, improve the focusing speed and stability while ensuring high-precision focusing of the microscopic optical system has become a technical problem that needs to be solved urgently in this field.

[0006] The present invention proposes an internal focusing microscope optical system, which aims to overcome the deficiencies in the prior art through an innovative focusing method, thereby providing a more accurate, stable and efficient focal length adjustment solution to meet the needs of modern microscopes in high-precision and high-frequency focusing applications. Summary of the invention

[0007] In order to overcome the above-mentioned shortcomings, an internal focusing microscope optical system is proposed, which has the characteristics of diffraction-level high resolution, large numerical aperture (NA) 0.3, paraxial magnification (PMAG) -8.9, working wavelength 630nm, low distortion, etc., and also has the characteristics of internal focusing function and short conjugate distance.

[0008] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: to provide an internal focusing microscope optical system. It is composed of an object plane, a first transmission group with positive optical power, a second transmission group with negative optical power, and an image plane arranged in sequence from the object side to the image side, the first transmission group is composed of a first biconcave lens, a first biconvex lens, a second biconvex lens, a positive meniscus lens, a third biconvex lens, and a second biconcave lens arranged in sequence from the object side to the image side, and the second transmission group is composed of a third biconcave lens; According to the internal focusing microscope optical system described in the present invention, a further preferred technical solution is: the ratio range of the focal length of the first transmission group to the focal length of the optical system is (2.5, 3.5); the ratio range of the focal length of the second transmission group to the focal length of the optical system is (-2.1, -1.5).

[0009] According to the internal focusing microscope optical system described in the present invention, a further preferred technical solution is that the second transmission group is a motion compensation component for internal focusing.

[0010] According to the internal focusing microscope optical system described in the present invention, a further preferred technical solution is: the first biconcave lens and the second biconcave lens are made of heavy flint glass, the first biconvex lens is made of lanthanum flint glass, the second biconvex lens and the positive meniscus lens are made of lanthanum crown glass, the third biconvex lens is made of crown glass, and the third biconcave lens is made of barium crown glass.

[0011] According to the internal focusing microscope optical system described in the present invention, a further preferred technical solution is: the first biconcave lens and the first biconvex lens are glued to form a first double glued lens, and the third biconvex lens and the second biconcave lens are glued to form a second double glued lens.

[0012] Compared with the prior art, the technical solution of the present invention has the following advantages / benefits: 1. The optical system of the present invention has the characteristics of diffraction-level high resolution, large numerical aperture (NA) 0.3, paraxial magnification (PMAG) -8.9, working wavelength 630nm, short conjugate distance, low distortion, etc., which can meet the needs of modern microscopes in high-precision and high-frequency focusing applications.

[0013] 2. The second transmission group is an internal focusing motion compensation group, which has an internal focusing motion compensation function and can compensate for the image plane offset error caused by object distance error and system parts error through the forward and backward movement of the second transmission group.

[0014] 3. The optical system of the present invention consists of an object plane, a first transmission group, a second transmission group, and an image plane. A total of 7 lenses are all spherical lenses made of glass. The manufacturing cost is relatively low, which is conducive to reducing costs for promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 The present invention is a schematic diagram of the optical system structure of an internal focusing microscope optical system.

[0017] Figure 2 It is a modulation transfer function curve diagram of an internal focusing microscope optical system of the present invention.

[0018] Figure 3 The present invention discloses a spot diagram of an internal focusing microscope optical system.

[0019] Figure 4 The optical path difference curve diagram of an internal focusing microscope optical system of the present invention.

[0020] Figure 5 It is a distortion diagram of an internal focusing microscope optical system of the present invention.

[0021] The markings in the figure are: 1. first biconcave lens, 2. first biconvex lens, 3. second biconvex lens, 4. positive meniscus lens, 5. third biconvex lens, 6. second biconcave lens, 7. third biconcave lens, 8. object plane, 9. image plane, G1. first transmission group, G2. second transmission group. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention are clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention. Therefore, the detailed description of the embodiments of the present invention provided below is not intended to limit the scope of the claimed invention, but merely represents the selected embodiments of the present invention.

[0023] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and thus, once an item is defined in one drawing, it may not be further defined or explained in the subsequent drawings.

[0024] Embodiment 1: like Figure 1As shown, an internal focusing microscope optical system. The lens is composed of an object plane 8, a first transmission group G1 with positive optical power, a second transmission group G2 with negative optical power, and an image plane 9, which are arranged in sequence from the object side to the image side. The first transmission group G1 has positive optical power and is composed of a total of 6 lenses, which are: a first biconcave lens 1 made of heavy flint glass, a first biconvex lens 2 made of lanthanum flint glass, a second biconvex lens 3 made of lanthanum crown glass, a positive meniscus lens 4 made of lanthanum crown glass, a third biconvex lens 5 made of crown glass, and a second biconcave lens 6 made of heavy flint glass. Of course, using different glasses to manufacture the lenses is only a relatively excellent solution. When necessary, other materials can also be used for manufacturing, as long as the use requirements are met; the first biconcave lens 1 and the first biconvex lens 2 are glued to form a first double glued lens, and the third biconvex lens 5 and the second biconcave lens 6 are glued to form a second double glued lens. The glued lens is a way of combining two lenses. This is only a combination means, and other similar reasonable means can be used. The first transmission group G1 is mainly used to correct system aberrations such as spherical aberration, coma, sine difference, field curvature, distortion, etc., and to correct chromatic aberration through double gluing.

[0025] The first transmission group G2 has negative optical power and is composed of one lens, which is a third biconcave lens 7 made of barium crown glass. The first transmission group G2 is an internal focusing motion compensation component, which compensates for the image plane 9 offset error caused by the object distance error and the system parts error through the forward and backward movement of the first transmission group G2.

[0026] The ratio of the focal length of the first transmission group G1 to the focal length of the optical system is in the range of (2.5, 3.5); the ratio of the focal length of the first transmission group G2 to the focal length of the optical system is in the range of (-2.1, -1.5).

[0027] Embodiment 2: Based on Example 1, this example provides an example of an internal focusing microscope optical system. The physical parameters of each lens in this example meet the data requirements shown in Table 1: Table 1 Physical parameters of each lens in this embodiment The internal focusing microscope optical system of this embodiment has an operating wavelength of 630±20nm, an object distance of 14mm, an object height of 0.28mm, and a numerical aperture (NA) of 0.3; the light emitted from the object plane passes through the first transmission group G1 and the second transmission group G2 in sequence and is imaged to the image plane 9 to form an image with an image height of 2.5mm; it has the characteristics of diffraction-level high resolution, paraxial magnification (PMAG) of -8.9, low distortion (about 1.0%), short conjugate distance (66.2mm), internal focusing function, etc.

[0028] Figure 2 The modulation transfer function (MTF) curve of the internal focusing microscope optical system of this embodiment is given. In the figure, the vertical coordinate OTF coefficient is the fast Fourier transform modulation transfer function, and the horizontal coordinate is the spatial frequency: line pairs per millimeter. It can be seen from the figure that the modulation transfer function (MTF) of the internal focusing microscope optical system is close to the diffraction limit.

[0029] Figure 3 Spot diagrams of the internal focusing microscope optical system of this embodiment are given. The unit of the legend in the figure is μm. It can be seen from the figure that the RMS spot radius of the internal focusing microscope optical system in each field of view is less than 2 μm.

[0030] Figure 4 The optical path difference (Optical Path Difference) curve of the internal focusing microscope optical system of this embodiment is given, in which ex: light aberration x component, ey: light aberration y component, px: x entrance pupil coordinate, py: y entrance pupil coordinate. It can be seen from the figure that the optical path difference (Optical Path Difference) of the internal focusing microscope optical system is less than 0.2 wavelength.

[0031] Figure 5 The distortion of the internal focusing microscope optical system of this embodiment is given. It can be seen from the figure that the optical distortion of the optical system is about 1.0%.

[0032] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0033] The above are only preferred embodiments of the present invention. It should be noted that the above preferred embodiments should not be regarded as limiting the present invention, and the protection scope of the present invention should be based on the scope defined by the claims. For ordinary technicians in this technical field, several improvements and modifications can be made without departing from the spirit and scope of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. An internal focusing microscope optical system, characterized in that: The invention is composed of an object plane, a first transmission group with positive optical focal length, a second transmission group with negative optical focal length, and an image plane, which are arranged in sequence from the object side to the image side. The first transmission group is composed of a first biconcave lens, a first biconvex lens, a second biconvex lens, a positive meniscus lens, a third biconvex lens, and a second biconcave lens, which are arranged in sequence from the object side to the image side. The second transmission group is composed of a third biconcave lens.

2. The internal focusing microscope optical system according to claim 1, characterized in that: The ratio of the focal length of the first transmission group to the focal length of the optical system is in the range of (2.5, 3.5); the ratio of the focal length of the second transmission group to the focal length of the optical system is in the range of (-2.1, -1.5).

3. The internal focusing microscope optical system according to claim 1, characterized in that: The second transmission group is an internal focusing motion compensation component.

4. The internal focusing microscope optical system according to claim 1, characterized in that: The first biconcave lens and the second biconcave lens are made of heavy flint glass, the first biconvex lens is made of lanthanum flint glass, the second biconvex lens and the positive meniscus lens are made of lanthanum crown glass, the third biconvex lens is made of crown glass, and the third biconcave lens is made of barium crown glass.

5. The internal focusing microscope optical system according to claim 1, characterized in that: The first biconcave lens and the first biconvex lens are glued together to form a first double glued lens, and the third biconvex lens and the second biconcave lens are glued together to form a second double glued lens.

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