Imaging system, manufacturing method and imaging device

Abstract

The present invention relates to an imaging system, a manufacturing method, and an imaging device. The imaging system includes, in order from the object side to the image side along an optical axis, a light source configured to provide a light beam to be irradiated onto a sample, an imaging lens group configured to receive the light beam transmitted through the sample and perform at least one imaging on the sample, and a phase modulation unit configured to modulate the light beam transmitted through the imaging lens group to form a desired sample image on an imaging plane of the imaging system, where the plane where the phase modulation unit is located and the plane where the light source is located are a pair of conjugate planes, and no lens or lens group performing a Fourier transform is introduced in the optical path between at least the plane where the phase modulation unit is located and the imaging plane of the imaging system. The imaging system can achieve more diverse imaging effects, avoid a decrease in resolution, and improve imaging quality without essentially requiring any modification to the existing microscope imaging optical path.

Description

[Technical Field]

[0001] The present invention relates to the field of optical imaging technology, and in particular to imaging systems, manufacturing methods and imaging devices. [Background technology]

[0002] To realize the observation of weak-contrast transparent samples such as living organisms using an optical microscope, the phase factor of the sample plays an important role. In the field of microscopy, to facilitate the observation of weak-contrast samples, it is mainstream to enhance the phase information of the sample using traditional phase contrast microscopes, Hoffman phase contrast microscopes, differential interference contrast microscopes, etc.

[0003] However, due to the limited imaging effect of the above-mentioned types of microscopes, Frey A. Davis et al. proposed a spiral phase contrast imaging system based on a 4f system in 2000 to simultaneously achieve both contour-enhanced and relief imaging effects in a single imaging system. This system utilizes a pair of confocal lenses and a spatial light modulator with a spiral phase in the imaging light path for filtering, ultimately achieving a contour-enhanced or relief image on the imaging plane.

[0004] However, the spiral phase-contrast imaging system based on the above 4f system does not have high imaging resolution and has certain optical distortions, so it requires adjusting the existing imaging optical path, making it difficult to directly integrate into commercial optical imaging systems. Summary of the Invention [Problem to be solved by the invention]

[0005] According to various embodiments of the present application, to solve at least one of the above problems, an improved imaging system, a manufacturing method and an imaging device, an improved objective lens module, an element combination and an external module, and an improved external imaging module and element combination are provided. [Means for solving the problem]

[0006] According to one aspect of the present application, there is provided an imaging system, the imaging system including, sequentially from an object side to an image side along an optical axis, a light source configured to provide a light beam to be irradiated onto a sample, an imaging lens group configured to receive the light beam transmitted through the sample and perform at least one imaging on the sample, and a phase modulation unit configured to modulate the light beam transmitted through the imaging lens group to form a desired sample image on an image plane of the imaging system; Here, the plane on which the phase modulation unit is located and the plane on which the light source is located are a pair of conjugate planes, and no lens or lens group performing a Fourier transform is introduced in the optical path at least between the plane on which the phase modulation unit is located and the imaging plane of the imaging system.

[0007] According to another aspect of the present application, there is provided an imaging system, the imaging system including, sequentially from an object side to an image side along an optical axis, a light source configured to provide a light beam to be irradiated onto a sample, an imaging lens group configured to receive the light beam transmitted through the sample and perform at least one imaging on the sample, and a phase modulation unit configured to modulate the light beam transmitted through the imaging lens group to form a desired sample image on an image plane of the imaging system; Here, the imaging system has a target plane conjugate to the plane where the light source is located, the plane where the phase modulation unit is located is located between the rear focal plane of the imaging lens group and the target plane, and no lens or lens group performing a Fourier transform is introduced in the optical path at least between the plane where the phase modulation unit is located and the imaging plane of the imaging system.

[0008] According to another aspect of the present application, there is provided an imaging system comprising, in sequence from the object side to the image side along an optical axis, a light source configured to provide a light beam to be irradiated onto a sample, an imaging lens group configured to receive the light beam transmitted through the sample and perform at least one imaging on the sample, and a phase modulation unit configured to modulate the light beam transmitted through the imaging lens group to form a desired sample image on an imaging plane of the imaging system, wherein the plane on which the phase modulation unit is located and the plane on which the light source is located are a pair of conjugate planes, and the phase modulation unit is adjacent to the imaging plane of the imaging system.

[0009] According to another aspect of the present application, there is provided an imaging system comprising, in sequence from the object side to the image side along an optical axis, a light source configured to provide a light beam to be irradiated onto a sample; an imaging lens group configured to receive the light beam transmitted through the sample and perform at least one imaging on the sample; and a phase modulation unit configured to modulate the light beam transmitted through the imaging lens group to form a desired sample image on an image plane of the imaging system, wherein the plane on which the phase modulation unit is located and the plane on which the light source is located are a pair of conjugate planes, and an intermediate lens group is provided between the phase modulation unit and the image plane of the imaging system, and the rear focal plane of the intermediate lens group is shifted from the image plane of the imaging system.

[0010] According to another aspect of the present application, there is provided a method for manufacturing an imaging system, comprising the steps of providing a light source, an imaging lens group, and a phase modulation unit; sequentially arranging the light source, the imaging lens group, and the phase modulation unit along the optical axis of the imaging lens group; and adjusting the position of the phase modulation unit so that a plane on which the phase adjustment unit is located and a plane on which the light source is located form a pair of conjugate planes, wherein no lens or lens group performing a Fourier transform is introduced in the optical path between at least the plane on which the phase modulation unit is located and the image plane of the imaging system.

[0011] According to another aspect of the present application, there is provided an imaging device, comprising an imaging system as described above and a photosensitive element, wherein a photosensitive surface of the photosensitive element overlaps an imaging surface of the imaging system.

[0012] According to another aspect of the present application, there is provided an objective lens module, the objective lens module including: a housing; an imaging lens group disposed within the housing, the imaging lens group configured to receive light beams irradiated onto a sample from a light source and transmitted through the sample, and to perform at least one imaging operation on the sample; and a phase modulation unit disposed within the housing, the phase modulation unit configured to modulate the light beams transmitted through the imaging lens group to form a desired sample image on an imaging plane of the objective lens module, Here, the plane on which the phase modulation unit is located and the plane on which the light source is located are a pair of conjugate planes, and no lens or lens group performing a Fourier transform is introduced in the optical path at least between the plane on which the phase modulation unit is located and the image plane of the objective lens module.

[0013] According to another aspect of the present application, a combination of elements is provided, comprising: a light source configured to provide a light beam to be irradiated onto a sample; and an external module having a connection portion connectable to an objective lens, wherein the external module further comprises a phase modulation unit; When the external module is connected to an objective lens via the connection part, the phase modulation unit is configured to modulate the light beam transmitted through the objective lens to form a desired sample image on the image plane of the objective lens, wherein the plane in which the phase modulation unit is located is conjugate to the plane in which the light source is located, and no lens or lens group performing a Fourier transform is introduced in the optical path at least between the plane in which the phase modulation unit is located and the image plane of the objective lens.

[0014] According to another aspect of the present application, there is provided an external module, which is applied to the combination as described above, and the external module includes a housing for accommodating the phase modulation unit, and the housing is provided with the connection portion.

[0015] According to another aspect of the present application, there is provided an external imaging module, the external imaging module including: a housing; an imaging lens group disposed within the housing, configured to receive light rays transmitted through an objective lens and perform a second or subsequent imaging of a sample, the objective lens being configured to receive light rays irradiated onto the sample from a light source and transmitted through the sample and perform a first imaging of the sample; and a phase modulation unit disposed within the housing, configured to modulate the light rays transmitted through the imaging lens group to form a desired sample image on an image plane of the external imaging module; Here, the plane on which the phase modulation unit is located and the plane on which the light source is located are a pair of conjugate planes, and no lens or lens group performing a Fourier transform is introduced in the optical path at least between the plane on which the phase modulation unit is located and the imaging plane of the external imaging module.

[0016] According to another aspect of the present application, a combination of elements is provided, adapted for use in a microscope, including a light source configured to provide a light beam that is irradiated onto a sample, and an external imaging module as described above.

[0017] The details of one or more embodiments of the application are set forth in the drawings and description below. Other features, objects, and advantages of the application will become apparent from the description, drawings, and claims. [Brief explanation of the drawings]

[0018] To better describe and explain the embodiments or examples of the inventions disclosed herein, reference may be made to one or more drawings. Additional detail or examples for the purpose of illustrating the drawings should not be considered as limiting the scope of the disclosed inventions, either of the presently described embodiments or examples or the best modes of these inventions as currently understood. [Figure 1] FIG. 2 is a schematic diagram of an imaging optical path according to an embodiment of the present application. [Figure 2] FIG. 2 is a schematic diagram of an imaging optical path according to an embodiment of the present application. [Figure 3]FIG. 2 is a schematic diagram of a member connection according to an embodiment of the present application. [Figure 4] FIG. 10 is a schematic diagram illustrating adjusting a phase modulation unit for centering and decentering in one embodiment of the present application. [Figure 5] FIG. 2 is a schematic diagram of an imaging optical path according to an embodiment of the present application. [Figure 6] FIG. 10 is a schematic diagram illustrating the adjustment of the front lens for centering and decentering in one embodiment of the present application. [Figure 7] FIG. 2 is a schematic diagram of an imaging optical path according to an embodiment of the present application. [Figure 8] FIG. 10 is a comparative diagram of 10x magnification microscopy phase contrast images produced in one embodiment of the present application. [Figure 9] FIG. 10 is a comparative diagram of 20x magnification microscopic phase contrast images produced in accordance with one embodiment of the present application. [Figure 10] FIG. 10 is a comparative diagram of 40x magnification microscopy phase contrast images produced in one embodiment of the present application. [Figure 11] 1 is a schematic diagram of the structure of an objective lens module according to an embodiment of the present application; [Figure 12] 1 is a schematic diagram of the structure of an objective lens module according to an embodiment of the present application; [Figure 13] 1 is a schematic diagram of a comparison of tumor cell samples observed with an objective lens module at 10x magnification in one embodiment of the present application. [Figure 14] 1 is a 20x magnified schematic diagram of a tumor cell sample observed through an objective lens module when the image of the light source overlaps with the center of the SPP in one embodiment of the present application. [Figure 15] 1 is a 40x magnification schematic diagram of a tumor cell sample observed with an objective lens module when the image of the light source overlaps with the center of the SPP in one embodiment of the present application. [Figure 16] This is a comparative image of unstained plant root slices observed with an objective lens module at 10x magnification in one example of the present application. [Figure 17] FIG. 1 is a comparative view of diatom samples observed with an objective lens module at 10x magnification in one embodiment of the present application. [Figure 18] FIG. 1 is a schematic diagram of a combination of elements according to an embodiment of the present application. [Figure 19] 1 is a schematic diagram of the combination of elements and the cooperation with an objective lens according to an embodiment of the present application; [Figure 20] FIG. 2 is a schematic diagram of the structure of an external module according to an embodiment of the present application. [Figure 21] 1 is a schematic diagram of the structure of an external imaging module according to an embodiment of the present application; [Figure 22] 1 is a schematic diagram of the structure of an external imaging module according to an embodiment of the present application; [Figure 23] FIG. 10 is a comparative diagram of 10x magnification microscopy phase contrast images produced in one embodiment of the present application. [Figure 24] FIG. 10 is a comparative diagram of 20x magnification microscopic phase contrast images produced in accordance with one embodiment of the present application. [Figure 25] FIG. 10 is a comparative diagram of 50x magnification microscopy phase contrast images produced in one embodiment of the present application. [Figure 26] FIG. 1 is a schematic diagram of a structure of a combination of elements according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0019] In order to make the technical solutions and beneficial effects of the present invention clearer and easier to understand, the following detailed description will be given by way of specific examples. Here, the drawings are not necessarily drawn to scale, and local features may be enlarged or reduced to more clearly show the details of local features. Unless otherwise defined, technical and scientific terms used in this application have the same meanings as those in the technical field to which this application belongs.

[0020] Furthermore, the terms "first" and "second" are merely descriptive and should not be understood to express or imply relative importance or the number of technical features being presented. Thus, a feature qualified by "first" or "second" may expressly or implicitly include at least one of the feature. In describing the present invention, "plurality" means two or more, for example, two, three, etc., unless otherwise clearly and specifically limited.

[0021] It should be noted that when an element is said to be "fixed" or "mounted" to another element, it may be directly on the other element or there may be intervening elements present. When an element is considered to be "connected" to another element, it may be directly connected to the other element or there may be intervening elements present. Terms such as "vertical," "horizontal," "above," "below," "left," "right," and similar expressions used herein are for descriptive purposes only and do not represent the only embodiment.

[0022] In this specification, the space on the side where an object is located relative to an optical element is referred to as the object side of the optical element, and correspondingly, the space on the side where an image formed by the object is located relative to the optical element is referred to as the image side of the optical element. In this specification, the positional relationship of "adjacent" indicates that, ignoring the aperture, no other elements are provided between the elements in the imaging system, between the element and the object plane, or between the element and the image plane. In this specification, the term "light source" includes not only an entity that emits light itself, but also an entity (such as a reflector) that reflects incident light rays and thereby irradiates the light rays onto a sample.

[0023] In this specification, the phase modulation unit may include one or more of a spiral phase plate (SPP), a holographic grating, a mode converter including a spherical lens and a cylindrical lens, and a spatial light modulator. Here, the spiral phase plate, also known as a spiral phase plate, a vortex light element, or a Bessel amplitude modulation spiral phase plate, can convert input Gaussian light into a circular energy ring, i.e., generate vortex light. Its structure resembles the shape of a spiral or spiral staircase, and the purpose of such a spiral design is to control the phase of the vortex beam. The spiral phase plate is the simplest, most direct, and most versatile way to obtain vortex light. The diameter and topological charge of the vortex light can be easily designed to meet the user's actual needs. Currently, in addition to using a spiral phase plate to generate a vortex beam, there are also many other ways to generate a vortex beam, for example, a holographic grating can be utilized to generate a vortex beam from a low-order Gaussian light, a mode converter including a spherical lens and a cylindrical lens can be used to obtain a vortex beam from a high-order Hermite element Gaussian light, and a spatial light modulator can also be selected to generate a vortex beam.

[0024] To achieve three-dimensional microscopic imaging of transparent samples, traditional phase contrast microscopes, Hoffman phase contrast microscopes, and differential interference contrast microscopes are typically used to enhance the phase information of transparent samples and thereby observe them. Specifically, phase contrast microscopes are based on the Abbe imaging principle and utilize a transmission ring in the light source and a dark-field phase ring at the back focal plane of the objective lens to convert phase information into amplitude information for observing transparent samples. Hoffman phase contrast microscopes combine an oblique incidence light source with a Hoffman gradation filter to obtain three-dimensional morphological information of transparent samples. Differential interference contrast microscopes utilize two slightly offset incident lights, which, after irradiating the sample, carry the sample's phase gradient information and are then integrated into intensity information to display in the final image. As a result, the sample has a phase gradient position, which appears different from the light intensity distribution of a flat area, exhibiting an effect similar to a relief.

[0025] However, the imaging effects of the above-mentioned phase contrast microscopes have limitations. For example, phase contrast microscopes are usually used to achieve an edge-enhanced imaging effect, Hoffman phase contrast microscopes are usually used to achieve a relief imaging effect, and differential interference contrast microscopes are also usually used to achieve a relief imaging effect. In addition, Hoffman phase contrast microscopes and differential interference contrast microscopes also have requirements for the observed sample. For example, Hoffman microscopes are prone to producing light and dark background stripes when photographing thick samples, and differential interference contrast microscopes require a birefringent optical path, which means that the sample must not contain polarization-sensitive materials. All of the above limitations limit the scope of traditional phase contrast microscopes.

[0026] On the other hand, to solve the problem of the limited imaging effect of traditional microscopes, much research has been done on 4f filtering systems equipped with spiral phase plates. However, this type of system requires the use of a pair of lenses, that is, compared to the solution of the present application, this type of system requires the introduction of an additional lens to perform Fourier transform and inverse Fourier transform on the object light during the imaging process, which in turn leads to a decrease in imaging resolution and an increase in optical distortion, making it difficult to achieve both high and low imaging quality.

[0027] As described above, how to enrich the imaging effect of a phase contrast microscope while ensuring the imaging quality of the phase contrast microscope and minimizing changes to the existing optical path has become a problem that needs to be considered and solved.

[0028] Based on the above problems, the present application provides an imaging system in which a phase modulation unit is placed in a plane conjugate to the plane in which the light source is located, thereby avoiding the need to add a lens that performs an additional Fourier transform, and ensuring the imaging quality of the phase contrast microscope while enriching the imaging effect of the phase contrast microscope.

[0029] 1, one embodiment of the present application provides an imaging system 100. The imaging system 100 sequentially includes a light source 110 configured to provide a light beam to be irradiated onto a sample from an object side to an image side along an optical axis AX1, an imaging lens group 120 configured to receive the light beam transmitted through the sample and perform at least one imaging on the sample, and a phase modulation unit 130 configured to modulate the light beam transmitted through the imaging lens group 120 to obtain a desired sample image on an image plane of the imaging system.

[0030] Furthermore, the plane where the phase modulation unit 130 is located and the plane where the light source 110 is located are a pair of conjugate planes, and no lens or lens group that performs a Fourier transform is introduced in the optical path at least between the plane where the phase modulation unit 130 is located and the imaging plane 10B of the imaging system 100.

[0031] 1 shows the imaging optical path of imaging system 100. During imaging, a sample is positioned between light source 110 and imaging lens group 120, and its location is indicated by object plane 10A. Light source 110 provides a light beam that is irradiated onto the sample, which is formed into a light beam carrying sample information after passing through the sample. The light beam carrying sample information passes through imaging lens group 120, and then passes through or is reflected by phase modulation unit 130, and finally reaches image plane 10B of imaging system 100.

[0032] Illustratively, the light source 110 includes a parallel light source and a point light source, and may also include a linear light source or a surface light source equivalent to a point light source. Illustratively, the imaging lens group 120 includes at least one converging lens. Illustratively, the imaging lens group 120 as a whole exerts a converging effect on light rays, or the imaging lens group 120 as a whole has positive focal power. Illustratively, when the light source 110 is a parallel light source, the plane on which the phase modulation unit 130 is located overlaps with the back focal plane of the imaging lens group 120.

[0033] For example, regarding conjugation, after an object is imaged by an optical system, if there is a one-to-one correspondence between an object point and an image point, the object point and the image point are a pair of conjugate points, and correspondingly, the plane where the object point is located and the plane where the image point is located are a pair of conjugate planes. Thus, when the light source 110 is an object point, the image formed by the light source 110 through the imaging lens group 120 becomes the image point of the light source 110. When the image point of the light source 110 is located on the plane where the phase modulation unit 130 is located, it indicates that the plane where the phase modulation unit 130 is located and the plane where the light source 110 is located are a pair of conjugate planes.

[0034] For example, "no lens or lens group performing a Fourier transform is introduced in the optical path between the plane where the phase modulation unit 130 is located and the image plane 10B of the imaging system 100" can be expressed as "no lens or lens group is provided in the optical path," or "a lens or lens group is provided in the optical path, but none of the lenses performs a Fourier transform on the light beam, or the entire lens group does not perform a Fourier transform on the light beam." On the other hand, there is an exact Fourier transform relationship between the front focal plane and the back focal plane of the lens (or the entire lens group), so that the back focal plane of the lens (or the entire lens group) can also be called the Fourier transform plane of the optical path, and when the back focal plane of the lens (or the entire lens group) overlaps with the image plane, it can be said that the lens or lens group in the optical path has performed an effective Fourier transform. To summarize the above, the fact that "no lens or lens group that performs a Fourier transform is introduced in the optical path between the plane where the phase modulation unit 130 is located and the imaging plane 10B of the imaging system 100" can be illustrated by the following two cases: (1) As shown in FIG. 1, when the phase modulation unit 130 is adjacent to the image plane 10B, i.e., when no other lens elements are additionally provided between the phase modulation unit 130 and the image plane 10B, a lens or lens group that performs a Fourier transform is necessarily introduced into the optical path between the phase modulation unit 130 and the image plane 10B. (2) As shown in FIG. 2, an intermediate lens group 240 is provided between the phase modulation unit 230 and the imaging plane 20B, but the rear focal plane 241 (i.e., the Fourier transform plane) of the intermediate lens group 240 is shifted from the imaging plane 20B.

[0035] The following describes the principle of how the imaging system 100 improves the imaging effect of a phase contrast microscope while ensuring the imaging quality of the phase contrast microscope, based on the imaging process of the imaging system 100, as follows: Under the paraxial approximation, the optical field distribution when a spherical wave emitted from a point source is transmitted to an object plane is as follows: E0(x0,y0)=α·exp[(ik / 2r)(x0 2 +y0 2 )]A(x0,y0), where R is the distance from the light source 110 to the object plane 10A on the optical axis AX1, x0 and y0 are spatial coordinates on the object plane 10A, A(x0, y0) is the sample transmission function, i is the imaginary unit, k is the wave number, α is a constant that does not affect the light field distribution, and exp is an exponential function with base e.

[0036] According to the Fresnel diffraction formula, the optical field distribution E1(x1, y1) just before the imaging lens group 120 can be obtained. Then, after being focused by the imaging lens group 120, the optical field distribution E2(x2, y2) can be obtained when the object light wave (i.e., a spherical wave carrying object information) is transmitted to the surface where the phase modulation unit 130 is located. Finally, after filtering, the optical field distribution of the object light wave on the imaging plane can be obtained. JPEG2026505530000002.jpg16170Here, x2 and y2 are spatial coordinates on the plane where the phase modulation unit 130 is located, x3 and y3 are spatial coordinates on the imaging plane 10B, γ and β are both constants, d1 indicates the distance between the plane where the phase modulation unit 130 is located on the optical axis AX1 and the imaging lens group 120, d2 indicates the distance between the plane where the phase modulation unit 130 is located on the optical axis AX1 and the imaging plane 10B, f is the focal length of the imaging lens group 120, F indicates the Fourier transform, u and v indicate the spectral coordinates of the Fourier transform, H(x2, y2) indicates the transmission function of the phase modulation unit 130, and λ indicates the wavelength.

[0037] As can be seen, E3(x3, y3) is essentially the same as the final optical field function formula for achieving phase contrast imaging using a 4f system, except for the addition of a quadratic phase factor that does not affect the optical field intensity distribution. Therefore, the configuration method of the present application achieves a phase contrast imaging effect that is essentially consistent with that of a 4f system without the need for an additional lens that performs a Fourier transform. Furthermore, the elimination of the lens is advantageous in reducing optical distortion and improving imaging resolution.

[0038] In the above-described imaging system 100, by introducing the phase modulation unit 130 into the imaging optical path and making the plane where the phase modulation unit 130 is located and the plane where the light source 110 is located a pair of conjugate planes, it is advantageous to realize a wider variety of imaging effects than bright-field observation (i.e., a microscope view with a flat visual effect), for example, it is possible to realize an imaging effect with emphasized boundaries and a relief imaging effect. In addition, since no lens or lens group that performs Fourier transform is introduced into the optical path between at least the plane where the phase modulation unit 130 is located and the imaging plane 10B of the imaging system 100, it is possible to avoid a decrease in resolution and improve imaging quality.

[0039] 3 , the imaging system 100 further includes a first housing 140 for accommodating the imaging lens group 120 and a second housing 150 for accommodating the phase modulation unit 130, where the first housing 140 and the second housing 150 are integrally molded or detachably connected. First, the first housing 140 can be used to fix the imaging lens group 120, and the second housing 150 can be used to fix the phase modulation unit 130. Second, when the first housing 140 and the second housing 150 are integrally molded, the imaging lens group 120 and the phase modulation unit 130 can be mounted in the same lens barrel. For example, they can be mounted together in an objective lens, which is advantageous for modularizing the imaging system 100. For example, when necessary, the objective lens can replace the original objective lens. When the first housing 140 and the second housing 150 are detachably connected, In this case, the imaging lens group 120 and the phase modulation unit 130 are respectively arranged in different housings. For example, the imaging lens group 120 is a lens group within the objective lens, while the housing containing the phase modulation unit 130 is an external module. Then, by assembling the housing containing the phase modulation unit 130 to the objective lens, the phase modulation unit 130 is positioned on a plane conjugate to the plane where the light source 110 is located. In this way, there is no need to change the structure of the objective lens, and the imaging system 100 can be obtained by simply assembling a simple external module, which greatly reduces manufacturing costs.

[0040] In some embodiments, the phase modulation unit includes a spiral phase plate. Different phase contrast imaging effects can be achieved by controlling the relative positional relationship between the image of the light source at the plane where the spiral phase plate is located and the center of the spiral phase plate. Illustratively, the transmission function of the spiral phase plate is H(r, θ)=circ(r / R spp )exp(ilθ), where circ denotes the pore size function, exp denotes the exponential function with base e, r is the radial coordinate, θ is the angular coordinate, l is an arbitrary integer, and R sppis the radius of the spiral phase plate.

[0041] For example, when the image of the light source on the plane where the spiral phase plate is located coincides with the center of the spiral phase plate, a phase contrast image with enhanced contours can be obtained. When the image of the light source on the plane where the spiral phase plate is located is shifted from the center of the spiral phase plate and the center of the spiral phase plate is still located on the plane where the spiral phase plate is located, a phase contrast image with a relief effect can be obtained. Figures 8, 9, and 10 show comparative phase contrast microscope images observed with 10x, 20x, and 40x objective lenses, respectively. As can be seen, when the images are observed under bright field at different magnifications, the detailed texture of the transparent sample is not clear; when the light source image is aligned with the center of the spiral phase plate (i.e., centered), the detailed contours of the transparent sample are emphasized; when the light source image is slightly decentered from the center of the spiral phase plate, the details of the transparent sample exhibit a light-dark distribution, resulting in a three-dimensional relief imaging effect; and when the light source image is decentered from the center of the spiral phase plate, the details of the transparent sample show an obvious relief imaging effect.

[0042] Below, three methods are provided for adjusting the relative positional relationship between the image of the light source on the plane where the spiral phase plate is located and the center of the spiral phase plate.

[0043] 4, when the position of the image 110' on the plane where the spiral phase plate (i.e., the phase modulation unit 130) of the light source 110 is located is fixed, the position of the spiral phase plate can be adjusted to move the center (black circle) of the spiral phase plate between a first position 131 and a second position 132, thereby realizing overlap and misalignment between the center of the spiral phase plate and the image 110' of the light source. Illustratively, the imaging system 100 further includes a first adjustment mechanism (not shown) connected to the spiral phase plate, which can adjust the position of the spiral phase plate based on a user's operation. For example, the first adjustment mechanism can adjust the spiral phase plate in a two-dimensional plane, for example, can translate or rotate the spiral phase plate in the plane in which it is located, and can use, for example, a manual adjustment method (for example, a screw hole can be drilled in the housing that fixes the spiral phase plate, and the two-dimensional position of the spiral phase plate can be adjusted by cooperation between the screw and the screw hole), or can use, for example, an electric adjustment mechanism (for example, the two-dimensional position is adjusted by a drive motor).

[0044] Second, as shown in FIG. 6, when the center of the spiral phase plate is fixed at position 341, the image of the light source 310 in the plane where the spiral phase plate is located can be moved to allow the image of the light source and the center of the spiral phase plate to overlap or be misaligned. For example, as shown in FIG. 5, the imaging system 300 further includes a pre-lens 320 located between the light source 310 and the imaging lens group 330, the pre-lens 320 being configured to converge the light beams transmitted through the pre-lens 320 (the converged light beams are irradiated onto the sample), and a second adjustment mechanism (not shown) connected to the pre-lens 320, wherein the second adjustment mechanism can change the position of the pre-lens 320 based on a user's operation so that the image of the convergence point 310' of the light beams emitted from the light source 310 after passing through the pre-lens 320 in the plane where the spiral phase plate (i.e., the phase modulation unit 340) is located overlaps with the center of the spiral phase plate or is shifted from the center of the spiral phase plate. 5 and 6, when the second adjustment mechanism controls the front lens 320 to the third position, the image of the convergence point 310' of the light source 310 is 310'', in which case the image 310'' overlaps with the center of the spiral phase plate, and when the second adjustment mechanism controls the front lens 320 to the fourth position, the image of the convergence point 310' of the light source 310 is 310''', in which case the image 310''' is shifted from the center of the spiral phase plate. Exemplarily, the second adjustment mechanism may similarly be the manual or motorized adjustment mechanism described above.

[0045] Third, the position of the spiral phase plate and the position of the front lens can be changed synchronously; for example, a first adjustment mechanism and a second adjustment mechanism can be provided simultaneously, thereby making it easier to achieve overlap or misalignment between the image of the light source (or the light source convergence point) and the center of the spiral phase plate.

[0046] In some embodiments, the imaging system 100 further includes a filter disposed between the pre-lens 320 and the imaging lens group 330, configured to filter the light transmitted through the pre-lens before the light is irradiated onto the sample, thereby eliminating the influence of stray light from the environment on the imaging and improving the imaging quality.

[0047] In some embodiments, the imaging system 100 further includes a mounting stage for placing a sample, so that when the sample is thin, the distance from the object plane 10A of the imaging system 100 to the imaging lens group 120 can be expressed as the distance from the mounting stage to the imaging lens group 120 on the optical axis, and when the sample is thick, the distance from the object plane 10A of the imaging system 100 to the imaging lens group 120 needs to take into account the thickness of the sample, and can be expressed, for example, as the distance from the mounting stage to the imaging lens group 120 on the optical axis minus the thickness of the sample.

[0048] In some embodiments, as shown in FIG. 7 , the imaging lens group 420 includes at least one imaging lens 421 and at least one relay lens 422, arranged sequentially from the object side to the image side along the optical axis AX4, where a light beam carrying sample information passes through the at least one imaging lens 421 and the at least one relay lens 422 before reaching the phase modulation unit 430. Exemplarily, the at least one relay lens 422 includes a first relay lens 4221 and a second relay lens 4222. The provision of relay lenses is advantageous for accurate sample positioning and better focusing of light on the sample, thereby improving the clarity of the image. This is also advantageous for obtaining an objective lens module suitable for an inverted microscope, which makes it easier for users to observe live cells in culture.

[0049] 1 , in some embodiments, the plane where the phase modulation unit 130 is located overlaps with the back focal plane of the imaging lens group 120. There are two main reasons for this configuration: first, most existing microscope optical paths adopt a method of introducing a parallel light source, and in this case, the plane where the phase modulation unit 130 is located (i.e., a plane conjugate to the plane where the light source is located) coincides with the back focal plane of the imaging lens group 120; and second, there is a certain tolerance for the position of the phase modulation unit 130 along the optical axis AX1, and it is basically positioned between the back focal plane of the imaging lens group 120 and a plane conjugate to the plane where the light source 110 is located. In summary, using the back focal plane of the imaging lens group 120 as the location for the phase modulation unit 130 not only ensures the required imaging effect, but also facilitates the manufacture of the imaging system 100. The above configuration is applicable to most existing microscopes and is therefore convenient for industrialization.

[0050] 1 , in some embodiments, the imaging system 100 further includes a third adjustment mechanism (not shown) connected to the phase modulation unit 130 and configured to change the position of the phase modulation unit 130 in the optical axis direction based on a user's operation. There are three main reasons for providing the third adjustment mechanism: first, the third adjustment mechanism can be adapted to the illumination form of the point light source, making it easy to match the plane where the phase modulation unit 130 is located with the plane where the image of the point light source 110 is located; second, the positions of the rear focal planes of the imaging lens groups 120 with different magnifications are different, so by providing the third adjustment mechanism, it is easy to match the plane where the phase modulation unit 130 is located with the rear focal plane of the imaging lens groups 120 with different magnifications; and third, the third adjustment mechanism can be used to calibrate the position of the phase modulation unit 130 after a positional deviation occurs in the phase modulation unit 130. Exemplarily, the third adjustment mechanism may be a manual adjustment mechanism (for example, adjustment by a threaded rod or gear transmission) or an electric adjustment mechanism (adjustment by a drive motor).

[0051] In another embodiment of the present application, an imaging system is provided, which includes, in sequence from the object side to the image side along an optical axis, a light source configured to provide a light beam to be irradiated onto a sample; an imaging lens group configured to receive the light beam transmitted through the sample and perform at least one imaging on the sample; and a phase modulation unit configured to modulate the light beam transmitted through the imaging lens group to form a desired sample image on an image plane of the imaging system, wherein the imaging system has a target plane conjugate to the plane in which the light source is located, the plane in which the phase modulation unit is located is located between the back focal plane of the imaging lens group and the target plane, and no lens or lens group performing a Fourier transform is introduced in the optical path at least between the plane in which the phase modulation unit is located and the image plane of the imaging system.

[0052] The imaging system described above takes into consideration that there is a certain tolerance for the placement of the phase modulation unit in the light propagation direction, so that the phase modulation unit can basically be positioned between the target plane of the rear focal plane of the imaging lens group, in which case, compared with bright-field observation, more precise imaging effects can be achieved, such as boundary-enhanced imaging effects and relief imaging effects. In addition, since no lens or lens group performing Fourier transform is introduced into the optical path between at least the plane where the phase modulation unit is located and the imaging plane of the imaging system, a decrease in resolution can be avoided and imaging quality can be improved.

[0053] As shown in FIG. 1, another embodiment of the present application provides an imaging system 100, which sequentially includes a light source 110 configured to provide a light beam to be irradiated onto a sample from the object side to the image side along an optical axis AX1, an imaging lens group 120 configured to receive the light beam transmitted through the sample and perform at least one imaging on the sample, and a phase modulation unit 130 configured to modulate the light beam transmitted through the imaging lens group 120 to form a desired sample image on an image plane 10B of the imaging system 100, wherein the plane on which the phase modulation unit 130 is located and the plane on which the light source 110 is located are a pair of conjugate planes, and the phase modulation unit 130 is adjacent to the image plane 10B of the imaging system.

[0054] The imaging system 100 described above is advantageous in realizing a wider variety of imaging effects than bright-field observation by introducing the phase modulation unit 130 into the imaging optical path and making the plane where the phase modulation unit 130 is located and the plane where the light source 110 is located a pair of conjugate planes, for example, it can realize an imaging effect with emphasized boundaries and a relief imaging effect. In addition, since no lens or lens group that performs Fourier transform is introduced into the optical path between at least the plane where the phase modulation unit 130 is located and the imaging plane 10B of the imaging system 100, a decrease in resolution can be avoided and imaging quality can be improved.

[0055] As shown in FIG. 2, another embodiment of the present application provides an imaging system 200, which sequentially includes a light source 210 configured to provide a light beam to be irradiated onto a sample from the object side to the image side along an optical axis AX2; an imaging lens group 220 configured to receive the light beam transmitted through the sample and perform at least one imaging on the sample; and a phase modulation unit 230 configured to modulate the light beam transmitted through the imaging lens group 220 to form a desired sample image on an image plane 20B of the imaging system 200, wherein the plane where the phase modulation unit 230 is located and the plane where the light source 210 is located are a pair of conjugate planes, and an intermediate lens group 240 is provided between the phase modulation unit 230 and the image plane 20B of the imaging system 200, and the back focal plane of the intermediate lens group 240 is shifted from the image plane 20B of the imaging system 200.

[0056] The imaging system 200 described above is advantageous in realizing a wider variety of imaging effects than bright-field observation by introducing the phase modulation unit 230 into the imaging optical path and making the plane where the phase modulation unit 230 is located and the plane where the light source 210 is located a pair of conjugate planes, and can achieve, for example, an imaging effect with emphasized boundaries and a relief imaging effect. In addition, since no lens or lens group that performs Fourier transform is introduced into the optical path between at least the plane where the phase modulation unit 230 is located and the imaging plane 20B of the imaging system 200, a decrease in resolution can be avoided and imaging quality can be improved.

[0057] Another embodiment of the present application provides a method for manufacturing an imaging system, comprising: S100 provides a light source, an imaging lens group, and a phase modulation unit; S200: sequentially arranging a light source, an imaging lens group, and a phase modulation unit along an optical axis of the imaging lens group; The method includes a step S300 of adjusting the position of the phase modulation unit so that the plane where the phase modulation unit is located and the plane where the light source is located form a pair of conjugate planes, in which no lens or lens group that performs a Fourier transform is introduced into the optical path between at least the plane where the phase modulation unit is located and the imaging plane of the imaging system.

[0058] The above-mentioned manufacturing method of the imaging system sequentially arranges the light source, the imaging lens group, and the phase modulation unit, and adjusts the phase modulation unit to a plane conjugate with the plane where the light source is located, thereby obtaining an imaging system that is advantageous for realizing more diverse imaging effects. In addition, since no lens or lens group that performs Fourier transform is introduced into the optical path between at least the plane where the phase modulation unit is located and the imaging plane of the imaging system, a decrease in resolution can be avoided and imaging quality can be improved.

[0059] In some embodiments, the plane where the adjusted phase modulation unit is located overlaps with the back focal plane of the imaging lens group, which not only ensures the required imaging effect but also makes the imaging system easier to manufacture.

[0060] Another embodiment of the present application provides an imaging device, the imaging device including the imaging system and a photosensitive element described in the previous embodiments, wherein a photosensitive surface of the photosensitive element overlaps with an image surface of the imaging system. Specifically, the photosensitive element can be a complementary metal oxide semiconductor (CMOS) image sensor or a charge-coupled device (CCD) image sensor.

[0061] The above-mentioned imaging device can capture phase contrast microscopic images with different imaging effects, such as a phase contrast microscopic image with enhanced contours and a phase contrast microscopic image with a relief effect, by adjusting the relative positional relationship between the phase modulation unit and the imaging of the light source, and the captured phase contrast microscopic images have high imaging quality.

[0062] The present application further provides an objective lens module, which cooperates with an eyepiece to facilitate the user's observation of the transparent sample, or allows the objective lens module to capture an image of the transparent sample with a camera after imaging. The objective lens module of the present application places a phase modulation unit on a plane conjugate with the plane where the light source is located, thereby avoiding the need to add a lens that performs additional Fourier transform, enriching the imaging effect of the phase contrast microscope, while eliminating the need to change the existing microscope imaging optical path, and ensuring the imaging quality of the phase contrast microscope.

[0063] 11 , one embodiment of the present application provides an objective lens module 500, including a housing 510, an imaging lens group 520 disposed inside the housing 510 and configured to receive light rays irradiated onto a sample from a light source and transmitted through the sample, and perform at least one imaging operation on the sample, and a phase modulation unit 530 disposed inside the housing 510 and configured to modulate the light rays transmitted through the imaging lens group 520 to form a desired sample image on an imaging plane of the objective lens module 500. Furthermore, the plane where the phase modulation unit 530 is located and the plane where the light source is located are a pair of conjugate planes, and no lens or lens group performing a Fourier transform is introduced in the optical path between at least the plane where the phase modulation unit 530 is located and the imaging plane of the objective lens module 500. Illustratively, the imaging lens group 520 includes at least one converging lens. For example, the imaging lens group 520 as a whole exerts a converging effect on the light rays, or the imaging lens group 520 as a whole has a positive focal power.

[0064] During imaging, the sample is located between the light source and the imaging lens group 520, and the light source provides a light beam that is irradiated onto the sample, which, after passing through the sample, is formed into a light beam carrying sample information, and the light beam carrying sample information passes through the imaging lens group 520, then passes through or is reflected by the phase modulation unit 530, and finally reaches the imaging plane of the objective lens module 500.

[0065] For example, regarding conjugation, after an object is imaged by the optical system, if there is a one-to-one correspondence between an object point and an image point, the object point and the image point are a pair of conjugate points, and correspondingly, the plane where the object point is located and the plane where the image point is located are a pair of conjugate planes. Thus, when the light source is an object point, the image formed by the light source through the imaging lens group 520 becomes the image point of the light source, and when the image point of the light source is located on the plane where the phase modulation unit 530 is located, it indicates that the plane where the phase modulation unit 530 is located and the plane where the light source is located are a pair of conjugate planes.

[0066] For example, "no lens or lens group performing a Fourier transform is introduced in the optical path between the plane where the phase modulation unit 530 is located and the image plane of the imaging system 500" can be expressed as "no lens or lens group is provided in the optical path," or "a lens or lens group is provided in the optical path, but none of the lenses performs a Fourier transform on the light beam, or the entire lens group does not perform a Fourier transform on the light beam." On the other hand, there is an exact Fourier transform relationship between the front focal plane and the back focal plane of the lens (or the entire lens group), so that the back focal plane of the lens (or the entire lens group) can also be called the Fourier transform plane of the optical path, and when the back focal plane of the lens (or the entire lens group) overlaps with the image plane, it can be said that the lens or lens group in the optical path has performed an effective Fourier transform. To summarize the above, the fact that "no lens or lens group performing a Fourier transform is introduced in the optical path between the plane where the phase modulation unit 530 is located and the imaging plane of the imaging system 500" can be illustrated by the following two cases: (1) As shown in Figure 11, when the phase modulation unit 530 is adjacent to the image plane, that is, when no other lens elements are additionally provided between the phase modulation unit 530 and the image plane, a lens or lens group that performs a Fourier transform is necessarily introduced into the optical path between the phase modulation unit 530 and the image plane. (2) An intermediate lens group is provided between the phase modulation unit 530 and the image plane, but the rear focal plane (ie, the Fourier transform plane) of the intermediate lens group is shifted from the image plane.

[0067] The objective lens module 500 introduces a phase modulation unit 530 into the microscope imaging optical path, and the plane where the phase modulation unit 530 is located and the plane where the light source is located are a pair of conjugate planes, thereby achieving more imaging effects, such as boundary-enhanced imaging effects and relief imaging effects, without changing the existing microscope imaging optical path. In addition, no lens or lens group that performs Fourier transform is introduced into the optical path between at least the plane where the phase modulation unit 530 is located and the imaging plane of the objective lens module 500, thereby avoiding a decrease in resolution and improving imaging quality.

[0068] 11 , in some embodiments, the housing 510 includes a light incident end 513, a light exit end 514, and a light passing hole 515 that passes through the light incident end 513 and the light exit end 514 along the optical axis AX5 of the objective lens module 500, where the imaging lens group 520 and the phase modulation unit 530 are both connected to the hole wall of the light passing hole. In the above manner, the phase modulation unit 530 can be integrated into an existing objective lens to obtain a dedicated spiral phase contrast objective lens, which can be directly used instead of a normal objective lens on a microscope when observing a transparent sample, thereby achieving effective observation of the transparent sample.

[0069] In some embodiments, the imaging lens group 520 includes at least one imaging lens and at least one relay lens arranged sequentially from the object side to the image side along the optical axis AX5, where light transmitted through the sample passes through at least one imaging lens and at least one relay lens before reaching the phase modulation unit 530. The provision of a relay lens is advantageous for accurate sample positioning and better focusing of light on the sample, thereby improving the clarity of the image. Furthermore, the solution of adding a phase modulation unit to an existing objective lens is not limited to the solution of adding a phase modulation unit to an existing objective lens. A plane conjugate to the plane where the light source is located can be found from the imaging light path extended by the relay lens, allowing for more freedom in selecting the position for the phase modulation unit, thereby enabling the objective lens module of this embodiment to be obtained. The objective lens module obtained in this embodiment can be applied to an inverted microscope, making it easier for users to observe cultured living cells.

[0070] In some embodiments, as shown in FIG. 12 , the housing 510 includes a first housing 511 and a second housing 512 that are removably connected, with the imaging lens group 520 disposed within the first housing 511 and the phase modulation unit 530 disposed within the second housing 512. This allows the objective lens module 500 to be divided into at least two independent modules, which facilitates cleaning. Furthermore, if one module is damaged, only the damaged module needs to be replaced, rather than the entire module, reducing maintenance costs. Furthermore, in this embodiment, the imaging lens group 520 can be replaced with the lens group of a conventional objective. This means that the existing objective does not need to be modified (i.e., it can be used with any existing objective). Simply attaching an external module equipped with the phase modulation unit 530 can achieve an imaging effect essentially identical to that of the aforementioned spiral phase contrast objective. This eliminates the need to separately purchase a spiral phase contrast objective or a mid- to high-end phase contrast microscope, significantly reducing costs.

[0071] 11 , the plane where the phase modulation unit 530 is located overlaps with the back focal plane of the imaging lens group 520. There are two main reasons for this configuration: first, most existing microscope optical paths adopt a method of introducing a parallel light source, and in this case, the plane where the phase modulation unit 530 is located (i.e., the plane conjugate to the plane where the light source is located) coincides with the back focal plane of the imaging lens group 520; and second, there is a certain tolerance for the position of the phase modulation unit 530 along the optical axis AX5, and it is basically positioned between the back focal plane of the imaging lens group 520 and the plane conjugate to the plane where the light source is located. To summarize, using the back focal plane of the imaging lens group 520 as the position for the phase modulation unit 530 in the objective lens module 500 not only ensures the required imaging effect, but also facilitates the manufacture of the objective lens module 500. The above configuration is applicable to most existing microscopes and is therefore convenient for industrialization.

[0072] In some embodiments, since the phase modulation unit 530 includes a spiral phase plate, when the image of the light source in the plane where the spiral phase plate is located overlaps with the center of the spiral phase plate, a phase contrast microscope image with enhanced contours can be obtained, and when the image of the light source in the plane where the spiral phase plate is located is shifted from the center of the spiral phase plate and the center of the spiral phase plate is still located in the plane where the spiral phase plate is located, a phase contrast microscope image with a relief effect can be obtained.

[0073] For example, Figures 13-15 show comparative diagrams at 10x magnification of tumor cell samples observed with an objective lens module, a schematic diagram of a tumor cell sample observed when the light source image overlaps the center of the SPP, and a schematic diagram of a tumor cell sample observed when the light source image overlaps the center of the SPP at 40x magnification, respectively. As can be seen from Figure 3, when the image is observed in bright field at the same magnification (i.e., a microscope image with a flat visual effect), the detailed texture of the transparent sample is not clear and the contrast of the cell image is poor. When the light source image overlaps the center of the spiral phase plate (i.e., centered), the detailed contours of the transparent sample are emphasized. When the light source image is offset from the center of the spiral phase plate (i.e., decentered), the contrast between the details of the transparent sample and the background is clear, forming a relief imaging effect. As can be seen from Figures 14 and 15, when the light source image overlaps the center of the spiral phase plate at different magnifications, the detailed contours of the transparent sample are all emphasized.

[0074] For example, Figure 16 shows a comparative image of an unstained plant rhizome slice at 10x magnification observed with an objective lens module. As can be seen, in an image observed in bright field at the same magnification, the detailed texture of the transparent sample is not clear, and the flat layer appears as a black mesh. When the light source image is aligned with the center of the spiral phase plate, the detailed contours of the transparent sample are emphasized. When the light source image is offset from the center of the spiral phase plate, the contrast between the details of the transparent sample and the background is clear, resulting in a relief imaging effect.

[0075] For example, Figure 17 shows a comparative image of a diatom sample observed with an objective lens module at 10x magnification. Because the diatom sample itself has a certain thickness, when observed using the objective lens module of this embodiment, the three-dimensional effect is stronger. As can be seen, when an image is observed in bright field at the same magnification, the detailed texture of the transparent sample is not obvious. However, when the light source image overlaps with the center of the spiral phase plate, the detailed outline of the transparent sample is emphasized.

[0076] Furthermore, the objective lens module 500 may include a first adjustment mechanism (not shown) to change the relative position between the image in the plane where the light source's spiral phase plate (i.e., the phase modulation unit 530) is located and the center of the spiral phase plate. Specifically, the first adjustment mechanism is connected to the spiral phase plate and configured to change the position of the spiral phase plate in the plane where the spiral phase plate is located based on a user's operation so that the center of the spiral phase plate overlaps with the image in the plane where the light source's spiral phase plate is located or is displaced from the image in the plane where the light source's spiral phase plate is located. Exemplarily, the first adjustment mechanism can translate or rotate the spiral phase plate in the plane where it is located, and may be, for example, a manual adjustment mechanism (e.g., a screw hole can be drilled in a housing that fixes the spiral phase plate, and the two-dimensional position of the spiral phase plate can be adjusted by cooperation between the screw and the screw hole) or an electric adjustment mechanism (e.g., adjustment by a drive motor).

[0077] In some embodiments, the objective lens module 500 may further include a second adjustment mechanism (not shown). Specifically, the second adjustment mechanism is connected to the phase modulation unit 530 and configured to change the position of the phase modulation unit 530 in the optical axis direction of the objective lens module 500 based on a user's operation. There are three main reasons for providing the second adjustment mechanism: first, the phase modulation unit 530 can be adapted to the illumination form of a point light source, making it easy to match the plane where the phase modulation unit 530 is located with the plane where the image of the point light source is located; second, the positions of the rear focal planes of the imaging lens groups 520 with different magnifications are different, so providing the second adjustment mechanism makes it easy to match the plane where the phase modulation unit 530 is located with the rear focal plane of the imaging lens groups 520 with different magnifications; and third, the second adjustment mechanism can be used to calibrate the position of the phase modulation unit 530 after a positional deviation occurs in the phase modulation unit 530. Illustratively, the second adjustment mechanism may be a manual adjustment mechanism (eg, adjustment by a threaded rod or gear transmission) or an electric adjustment mechanism (adjustment by a drive motor).

[0078] In some embodiments, the objective lens module 500 may also include a first adjustment mechanism and a second adjustment mechanism simultaneously to better achieve the desired phase contrast imaging effect and ensure the reliability of the objective lens module 500.

[0079] 18 and 19 , another embodiment of the present application provides an element combination 600, including a light source 610 configured to provide a light beam to be irradiated onto a sample, and an external module 620 having a connector 621 connectable to an objective lens, where the external module 620 further includes a phase modulation unit 622, and when the external module 620 is connected to the objective lens via the connector 621, the phase modulation unit 622 is configured to modulate the light beam transmitted through the objective lens to form a desired sample image on an image plane of the objective lens module having the objective lens, where the plane where the phase modulation unit 622 is located is conjugate with the plane where the light source 610 is located, and no lens or lens group performing Fourier transform is introduced in the optical path between at least the plane where the phase modulation unit 622 is located and the image plane of the objective lens module. Here, with regard to "no lens or lens group performing Fourier transform is introduced in the optical path," reference can be made to the description in the previous embodiment, and detailed description thereof will be omitted here.

[0080] The above-mentioned element combination 600 provides a light source 610 and an external module 620 equipped with a phase modulation unit 622, and the light source 610 illuminates the sample. By simply connecting the external module 620 to the light output end of the objective lens, it is possible to achieve an imaging effect that is basically the same as that of a spiral phase contrast objective lens without requiring any modifications to the existing objective lens. This eliminates the need to separately purchase a spiral phase contrast objective lens or a mid- to high-end phase contrast microscope, thereby significantly reducing costs.

[0081] Illustratively, the light source 610 includes a parallel light source or a point light source. Illustratively, when the light source 610 is a parallel light source, the plane where the phase modulation unit 622 is located overlaps with the back focal plane of the objective lens.

[0082] For example, the image plane of the objective lens module may be an image plane where a sample is observed using the entire lens system including the objective lens to form an image of the sample, i.e., the objective lens module may be provided with only the objective lens, or may further include lenses other than the objective lens.

[0083] In some embodiments, the phase modulation unit 622 includes a spiral phase plate, and the external module 620 further includes a first adjustment mechanism (not shown), which is connected to the phase modulation unit 622 and configured to change the position of the phase modulation unit 622 in the plane in which the phase modulation unit 622 is located based on a user's operation so that when the external module 620 is connected to the objective lens via the connection portion 621, the center of the phase modulation unit 622 overlaps with or is shifted from the image of the phase modulation unit 622 of the light source 610 in the plane in which the phase modulation unit 622 of the light source 610 is located. As a result, when the first adjustment mechanism causes the image of the light source 610 on the plane where the phase modulation unit 622 is located to overlap with the center of the phase modulation unit 622, a phase contrast microscope image with an enhanced outline can be obtained, and when the image of the light source 610 on the plane where the phase modulation unit 622 is located is shifted from the center of the phase modulation unit 622 while the center of the phase modulation unit 622 is still positioned on the plane where the phase modulation unit 622 is located, a phase contrast microscope image with a relief effect can be obtained. For specific installation forms of the first adjustment mechanism, please refer to the above-mentioned embodiments, and detailed description will be omitted here.

[0084] In some embodiments, the external module 620 further includes a second adjustment mechanism (not shown), which is connected to the phase modulation unit and configured to change the position of the phase modulation unit in the optical axis direction of the objective lens based on a user's operation. The reasons for installing the second adjustment mechanism and the specific installation form of the second adjustment mechanism can be referred to the above-mentioned examples, and detailed description thereof will be omitted here.

[0085] In some embodiments, most existing microscope optical paths adopt a method of introducing a parallel light source. In this case, the plane where the phase modulation unit 622 is located (i.e., the plane conjugate to the plane where the light source is located) coincides with the back focal plane of the objective lens. In addition, there is a certain tolerance for the position of the phase modulation unit 622 along the optical axis direction, and it is basically positioned between the back focal plane of the objective lens and the plane conjugate to the plane where the light source 610 is located. Therefore, as shown in FIG. 19 , when the external module 620 is connected to the objective lens via the connection part 621, the plane where the phase modulation unit 622 is located can be set to overlap with the back focal plane of the objective lens, which not only ensures the required imaging effect but also facilitates the manufacture of the objective lens module 500. The above setting is applicable to most existing microscopes and is convenient for industrialization.

[0086] 20, another embodiment of the present application provides an external module 700, which can be applied to the combination of the above-mentioned elements. The external module 700 includes a housing 710 for accommodating a phase modulation unit 720, and the housing 710 is provided with a connection part 711 that can be connected to an objective lens.

[0087] When the above external module 700 is assembled to the objective lens, the plane where the phase modulation unit 720 is located can be conjugated with the plane where the light source is located, thereby realizing the required phase contrast imaging effect. On the other hand, for the microscope optical path where the light source is located, the external module 700 can be directly assembled to the objective lens, thereby achieving the required phase contrast imaging effect.

[0088] The present application further provides an external imaging module that cooperates with an objective lens to enable a camera to capture an image of a transparent sample. The external imaging module of the present application avoids the need for an additional lens that performs Fourier transform by placing a phase modulation unit in the added imaging optical path at a plane conjugate to the plane where the light source is located, thereby enriching the imaging effect of the phase contrast microscope, while eliminating the need to modify the existing microscope imaging optical path and ensuring the imaging quality of the phase contrast microscope.

[0089] As shown in FIG. 21 , one embodiment of the present application provides an external imaging module 800, which includes a housing 810, an imaging lens group 820 arranged inside the housing 810 and configured to receive light rays transmitted through an objective lens and perform a second or subsequent imaging on a sample, wherein the objective lens is configured to receive light rays irradiated onto the sample from a light source and transmitted through the sample and perform a first imaging on the sample, and a phase modulation unit 830 arranged inside the housing 810 and configured to modulate the light rays transmitted through the imaging lens group 820 to form a desired sample image on an imaging plane of the external imaging module 800, wherein the plane on which the phase modulation unit 830 is located and the plane on which the light source is located are a pair of conjugate planes, and no lens or lens group performing a Fourier transform is introduced in the optical path between at least the plane on which the phase modulation unit 830 is located and the imaging plane of the external imaging module 800. Illustratively, the imaging lens group 820 includes at least one converging lens. Illustratively, the imaging lens group 820 as a whole exerts a converging effect on light rays, or the imaging lens group 820 as a whole has a positive focal power.

[0090] During imaging, the light beam transmitted through the objective lens can be incident on the external imaging module 800 after the first imaging, and the external imaging module 800 can perform a second or subsequent imaging of the sample, where the light beam carrying the sample information passes through the imaging lens group 820, then passes through or is reflected by the phase modulation unit 830, and finally reaches the imaging plane of the external imaging module 800. Specifically, "the external imaging module 800 can perform a second or subsequent imaging of the sample" means the following: When the external imaging module 800 is directly adjacent to the objective lens, no other lens is introduced in the optical path between the objective lens and the external imaging module 800, in which case the external imaging module 800 performs a second imaging of the sample; on the other hand, when another lens is introduced in the optical path between the objective lens and the external imaging module 800, the other lens performs a second imaging of the sample, or a second or third imaging, in which case the external imaging module 800 performs a third or fourth imaging of the sample.

[0091] For example, regarding conjugation, after an object is imaged by the optical system, if there is a one-to-one correspondence between an object point and an image point, the object point and the image point are a pair of conjugate points, and correspondingly, the plane where the object point is located and the plane where the image point is located are a pair of conjugate surfaces. Therefore, when the light source is an object point, the image finally formed by the light source through the imaging lens group 820 becomes the image point of the light source, and when the image point of the light source is located on the plane where the phase modulation unit 830 is located, it indicates that the plane where the phase modulation unit 830 is located and the plane where the light source is located are a pair of conjugate surfaces.

[0092] For example, "no lens or lens group performing Fourier transform is introduced into the optical path between the plane where the phase modulation unit 830 is located and the image plane of the external imaging module 800" can be expressed as "no lens or lens group is provided in the optical path," or "a lens or lens group is provided in the optical path, but none of the lenses performs a Fourier transform on the light beam, or the entire lens group does not perform a Fourier transform on the light beam." On the other hand, there is an exact Fourier transform relationship between the front focal plane and the back focal plane of the lens (or the entire lens group), so that the back focal plane of the lens (or the entire lens group) can also be called the Fourier transform plane of the optical path. When the back focal plane of the lens (or the entire lens group) overlaps with the image plane, it can be said that the lens or lens group in the optical path has performed an effective Fourier transform. To summarize the above, the fact that "no lens or lens group that performs a Fourier transform is introduced in the optical path between the plane where the phase modulation unit 830 is located and the imaging plane of the external imaging module 800" can be illustrated by the following two cases: (1) As shown in Figure 1, when the phase modulation unit 830 is adjacent to the image plane, that is, when no other lens elements are additionally provided between the phase modulation unit 830 and the image plane, a lens or lens group that performs a Fourier transform is necessarily introduced into the optical path between the phase modulation unit 830 and the image plane. (2) An intermediate lens group is provided between the phase modulation unit 830 and the image plane, but the rear focal plane (ie, the Fourier transform plane) of the intermediate lens group is shifted from the image plane.

[0093] The external imaging module 800 adds an additional imaging optical path after the existing microscope imaging optical path, and a phase modulation unit can be installed in the additional imaging optical path. The plane where the phase modulation unit is located and the plane where the light source is located are made into a pair of conjugate planes, so that more imaging effects, such as boundary-enhanced imaging effects and relief imaging effects, can be achieved without changing the existing microscope imaging optical path. In addition, since no lens or lens group performing Fourier transform is introduced into the optical path between at least the plane where the phase modulation unit 830 is located and the imaging plane of the external imaging module, adverse effects such as reduced resolution and increased optical distortion caused by introducing an additional lens can be avoided, and imaging quality can be improved.

[0094] In some embodiments, as shown in Figure 21, the housing 810 is provided with a connector 860 that can be connected to the imaging port of a microscope. Continuing to refer to Figure 1, the imaging port of the microscope is originally the final imaging plane (i.e., the original imaging plane of Figure 1), but here, an external imaging module 800 is added, and the final imaging plane can be projected as an intermediate image onto another distant imaging plane and then collected by a camera. In this case, the external imaging module 800 performs the final imaging of the sample. Providing a new imaging optical path at the imaging port of the microscope does not affect the existing microscope imaging optical path.

[0095] 21 , in some embodiments, the external imaging module 800 further includes a photosensitive element 850, where the photosensitive surface of the photosensitive element 850 overlaps with the imaging surface of the external imaging module 800. By providing the photosensitive element 850 on the imaging surface of the external imaging module 800, a microscopic phase contrast image of a transparent sample can be captured, where the photosensitive element can be, in particular, a complementary metal oxide semiconductor (CMOS) image sensor or a charge-coupled device (CCD) image sensor.

[0096] 21 , in some embodiments, a light-passing hole 840 is drilled in the housing 810, and the light-passing hole 840 extends from one end of the housing 810 along the optical axis direction of the external imaging module 800, where the imaging lens group 820 and the phase modulation unit 830 are both connected to the hole wall of the light-passing hole 840. In the above manner, the imaging lens group 820 and the phase modulation unit 830 can be integrated into one module, which makes it easy to attach and detach the external imaging module 800.

[0097] 22 , the housing 810 includes a first housing 811 and a second housing 812 that are detachably connected, where the imaging lens group 820 is provided inside the first housing 811 and the phase modulation unit 830 is provided inside the second housing 812. This allows the external imaging module 800 to be divided into at least two independent modules, which makes it easier to clean the external imaging module 800 and reduces maintenance costs because, if one of the modules is broken, it is not necessary to replace the entire module but only the broken module needs to be replaced.

[0098] In some embodiments, the plane where the phase modulation unit 830 is located overlaps with the back focal plane of the imaging lens group 820. There is a certain tolerance for the position of the phase modulation unit 830 along the optical axis direction, and it is basically positioned between the back focal plane of the imaging lens group 820 and a plane conjugate to the plane where the light source is located. In summary, using the back focal plane of the imaging lens group 820 as the position where the phase modulation unit 830 is located in the external imaging module 800 not only ensures the required imaging effect, but also facilitates the manufacture of the external imaging module 800, which is favorable for industrialization.

[0099] In some embodiments, the phase modulation unit 830 includes a spiral phase plate, whereby a phase contrast microscope image with enhanced contours can be obtained when the light source image in the plane where the spiral phase plate is located coincides with the center of the spiral phase plate. When the light source image in the plane where the spiral phase plate is located is shifted from the center of the spiral phase plate and the center of the spiral phase plate is still located in the plane where the spiral phase plate is located, a phase contrast microscope image with a relief effect can be obtained. Figures 23, 24, and 25 show comparative phase contrast microscope images of another transparent sample observed with 10x, 20x, and 50x objective lenses, respectively. As can be seen, at different magnifications, when the light source image coincides with the center of the spiral phase plate (i.e., centered), the detailed contours of the transparent sample are enhanced; when the light source image is decentered from the center of the spiral phase plate, the details of the transparent sample have a clear relief imaging effect.

[0100] Furthermore, the external imaging module 800 may include a first adjustment mechanism (not shown) to change the relative position between the image in the plane where the light source's spiral phase plate (i.e., the phase modulation unit 830) is located and the center of the spiral phase plate. Specifically, the first adjustment mechanism is connected to the spiral phase plate and configured to change the position of the spiral phase plate in the plane where the spiral phase plate is located based on a user's operation so that the center of the spiral phase plate overlaps with the image in the plane where the light source's spiral phase plate is located or is displaced from the image in the plane where the light source's spiral phase plate is located. Exemplarily, the first adjustment mechanism can translate or rotate the spiral phase plate in the plane where it is located. For example, the first adjustment mechanism may be a manual adjustment mechanism (e.g., a screw hole may be drilled in a housing that fixes the spiral phase plate, and the two-dimensional position of the spiral phase plate is adjusted by cooperation between the screw and the screw hole) or an electric adjustment mechanism (e.g., adjustment by a drive motor).

[0101] In some embodiments, the external imaging module 800 may further include a second adjustment mechanism (not shown). Specifically, the second adjustment mechanism is connected to the phase modulation unit 830 and configured to change the position of the phase modulation unit 830 in the optical axis direction of the external imaging module 800 based on a user's operation. There are two main reasons for providing the second adjustment mechanism: first, it can adapt to the illumination form of a point light source, making it easier to match the plane on which the phase modulation unit 830 is located with the plane on which the image of the point light source is located; and second, it can calibrate the position of the phase modulation unit 830 using the second adjustment mechanism after a positional deviation of the phase modulation unit 830 occurs. For example, the second adjustment mechanism may be a manual adjustment mechanism (e.g., adjustment using a threaded rod or gear transmission) or an electric adjustment mechanism (adjustment using a drive motor).

[0102] In some embodiments, the external imaging module 800 may also include the above-mentioned first and second adjustment mechanisms simultaneously to better achieve the desired phase contrast imaging effect and ensure the reliability of the external imaging module 800.

[0103] As shown in FIG. 26, another embodiment of the present application provides a combination of elements 900, applicable to a microscope, including a light source 910 configured to provide a light beam to be irradiated onto a sample, and an external imaging module 800 as described above.

[0104] The above-mentioned combination of elements 900 provides an external imaging module 800 equipped with a light source 910 and a phase modulation unit 830, and allows the light source 910 to illuminate the sample, thereby enabling the external imaging module 800 to achieve the desired phase contrast imaging effect, without requiring any modification to the existing microscope imaging optical path, while still ensuring imaging quality. This eliminates the need to purchase a mid- to high-end phase contrast microscope separately, significantly reducing costs.

[0105] It should be understood that the numbers expressing quantities or properties describing and claiming protection for certain embodiments of the present application may be modified, in some cases, by the terms "generally," "about," "approximately," or "essentially." For example, unless otherwise specified, "generally," "about," "approximately," or "essentially" may indicate a ±20% variation of the value described thereby. Correspondingly, in some embodiments, all numerical parameters used in the specification and claims are approximate values, and such approximations may be modified depending on the characteristics required for a particular embodiment. In some embodiments, numerical parameters should be calculated using conventional methods, taking into account the number of significant digits specified. In some embodiments, numerical ranges and parameters used to determine the breadth of a range are approximate values; however, in specific embodiments, such numerical values ​​are set as precisely as possible within the ranges possible.

[0106] It should be understood that the above examples are merely illustrative and are not intended to include all possible embodiments encompassed by the claims. Various modifications and variations may be made based on the above examples without departing from the scope of the present disclosure. Similarly, any combination of the technical features of the above examples may be used to form other embodiments of the present invention that may not be explicitly described. Therefore, the above examples merely represent some embodiments of the present invention and do not limit the patent protection scope of the present invention. [Explanation of symbols]

[0107] 100...imaging system, 110...light source, 110'-110'''...image of light source, 120...imaging lens group, 130...phase modulation unit, 131...first position, 132...second position, 140...first housing, 150...second housing, 10A...object plane, 10B...image plane, 200...imaging system, 210...light source, 220...imaging lens group, 230...phase modulation unit, 240...intermediate lens group, 241...back focal plane of intermediate lens group, 20A...object plane, 20B...image plane, 300...imaging system, 310...light source, 310'...convergence point of light source, 310''...image of convergence point of light source, 310''''...image of convergence point of light source after front lens position is changed , 320...pre-lens, 330...imaging lens group, 340...phase modulation unit, 341...center of phase modulation unit, 30A...object plane, 30B...image plane, 400...imaging system, 410...light source, 420...imaging lens group, 421...imaging lens, 422...relay lens group, 4221...first relay lens, 4222...second relay lens, 430...phase modulation unit, 40A...object plane, 40B...image plane, 500...objective lens module, 510...housing, 511...first housing, 512...second housing, 513...light beam entrance end, 514...light beam exit end, 515...light passing hole, 520...imaging lens group, 530...phase modulation unit, 600...combination of elements, 610...light source, 620...external module, 621...connection portion, 622...phase modulation unit, 700...external module, 710...housing, 711...connection portion, 720...phase modulation unit, 800...external imaging module, 810...housing, 811...first housing, 812...second housing, 820...imaging lens group, 830...phase modulation unit, 840...light passage hole, 850...photosensitive element, 860...connection portion, 900...combination of elements, 910...light source

Claims

1. a light source configured to provide a light beam that is irradiated onto the sample; an imaging lens group configured to receive the light beam transmitted through the sample and perform at least one imaging onto the sample; a phase modulation unit configured to modulate the light beam transmitted through the imaging lens group to form a desired sample image on an image plane of the imaging system, sequentially from the object side to the image side along the optical axis; where: a plane where the phase modulation unit is located and a plane where the light source is located are a pair of conjugate planes, and no lens or lens group performing a Fourier transform is introduced into an optical path between at least the plane where the phase modulation unit is located and an image plane of the imaging system; 1. An imaging system comprising:

2. The imaging system of claim 1 , wherein the light source comprises a parallel light source or a point light source.

3. The imaging system of claim 1 , wherein the phase modulation unit is adjacent to an imaging plane of the imaging system.

4. a first housing for accommodating the imaging lens group; a second housing for accommodating the phase modulation unit; Here, the first housing and the second housing are integrally formed or detachably connected.

2. The imaging system of claim 1.

5. 5. The imaging system according to claim 1, wherein the phase modulation unit includes a spiral phase plate.

6. further comprising a first adjustment mechanism connected to the phase modulation unit; Here, the first adjustment mechanism is configured to change the position of the phase modulation unit within the plane in which the phase modulation unit is located based on a user's operation so that the center of the phase modulation unit overlaps with an image of the light source in the plane in which the phase modulation unit is located, or is shifted from an image of the light source in the plane in which the phase modulation unit is located.

6. The imaging system of claim 5.

7. a front lens positioned between the light source and the imaging lens group and configured to converge light rays transmitted through the front lens; a second adjustment mechanism connected to the front lens; Here, the second adjustment mechanism is configured to change the position of the head lens based on a user's operation so that an image of a convergence point of the light beam emitted from the light source after passing through the head lens on a plane where the phase modulation unit is located overlaps with the center of the phase modulation unit or is shifted from the center of the phase modulation unit.

6. The imaging system of claim 5.

8. a filter disposed between the front lens and the imaging lens group and configured to filter the light beam transmitted through the front lens before the light beam is irradiated onto the sample; 8. The imaging system of claim 7.

9. The imaging lens group is at least one imaging lens; at least one relay lens, arranged sequentially from the object side to the image side along the optical axis; wherein the light beam carrying the sample information passes through the at least one imaging lens and the at least one relay lens in sequence, and then reaches the phase modulation unit; 5. The imaging system according to claim 1, wherein the first and second lenses are arranged in a plane parallel to each other.

10. a plane on which the phase modulation unit is located overlaps with a rear focal plane of the imaging lens group; 5. The imaging system according to claim 1, wherein the first and second lenses are arranged in a plane parallel to each other.

11. the imaging system a third adjustment mechanism connected to the phase modulation unit and configured to change a position of the phase modulation unit in the optical axis direction based on a user operation; 5. The imaging system according to claim 1, wherein the first and second lenses are arranged in a plane parallel to each other.

12. a light source configured to provide a light beam that is irradiated onto the sample; an imaging lens group configured to receive the light beam transmitted through the sample and perform at least one imaging onto the sample; a phase modulation unit configured to modulate the light beam transmitted through the imaging lens group to form a desired sample image on an image plane of the imaging system, sequentially from the object side to the image side along the optical axis; wherein the imaging system has a target plane conjugate with a plane where the light source is located, the plane where the phase modulation unit is located is located between the rear focal plane of the imaging lens group and the target plane, and no lens or lens group performing a Fourier transform is introduced into the optical path at least between the plane where the phase modulation unit is located and the image plane of the imaging system.

1. An imaging system comprising:

13. the imaging system includes, in order from the object side to the image side along the optical axis, a light source configured to provide a light beam to be irradiated onto a sample; an imaging lens group configured to receive the light beam transmitted through the sample and perform at least one imaging on the sample; and a phase modulation unit configured to modulate the light beam transmitted through the imaging lens group to form a desired sample image on an imaging plane of the imaging system, wherein a plane on which the phase modulation unit is located and a plane on which the light source is located are a pair of conjugate planes, and the phase modulation unit is adjacent to the imaging plane of the imaging system; 1. An imaging system comprising:

14. the imaging system includes, in order from the object side to the image side along the optical axis, a light source configured to provide a light beam to be irradiated onto a sample; an imaging lens group configured to receive the light beam transmitted through the sample and perform at least one imaging on the sample; and a phase modulation unit configured to modulate the light beam transmitted through the imaging lens group to form a desired sample image on an image plane of the imaging system, wherein a plane on which the phase modulation unit is located and a plane on which the light source is located are a pair of conjugate planes, and an intermediate lens group is provided between the phase modulation unit and the image plane of the imaging system, and a back focal plane of the intermediate lens group is shifted from the image plane of the imaging system; 1. An imaging system comprising:

15. providing a light source, an imaging lens group and a phase modulation unit; a step of sequentially arranging the light source, the imaging lens group, and the phase modulation unit along an optical axis of the imaging lens group; adjusting the position of the phase modulation unit so that a plane on which the phase adjustment unit is located and a plane on which the light source is located form a pair of conjugate planes; wherein a lens or lens group that performs a Fourier transform is not introduced into an optical path between at least a plane where the phase modulation unit is located and an image plane of the imaging system.

10. A method for manufacturing an imaging system comprising:

16. a plane on which the phase modulation unit is located after adjustment overlaps with a rear focal plane of the imaging lens group; The method of claim 15.

17. 15. An imaging system according to claim 1, comprising a photosensitive element and a photosensitive surface of the photosensitive element overlapping an imaging surface of the imaging system. An imaging device characterized by:

18. Housing and an imaging lens group provided inside the housing and configured to receive light rays irradiated onto a sample from a light source and transmitted through the sample, and to perform at least one imaging on the sample; a phase modulation unit disposed within the housing and configured to modulate the light beam transmitted through the imaging lens group to form a desired sample image on an imaging plane of the objective lens module; where: a plane where the phase modulation unit is located and a plane where a light source is located are a pair of conjugate planes, and no lens or lens group performing a Fourier transform is introduced into an optical path between at least the plane where the phase modulation unit is located and the image plane of the objective lens module; An objective lens module characterized by:

19. the housing includes a light incident end, a light exit end, and a light passing hole passing through the light incident end and the light exit end along an optical axis of the objective lens module; where: the imaging lens group and the phase modulation unit are both connected to the hole wall of the light passing hole; 19. The objective lens module according to claim 18.

20. the imaging lens group includes at least one imaging lens and at least one relay lens arranged in sequence from an object side to an image side along the optical axis, wherein the light beam transmitted through the sample passes through the at least one imaging lens and the at least one relay lens in sequence, and then reaches the phase modulation unit.

20. The objective lens module according to claim 19.

21. The housing includes a first housing and a second housing that are removably connected; where: the imaging lens group is provided inside the first housing, and the phase modulation unit is provided inside the second housing.

19. The objective lens module according to claim 18.

22. a plane on which the phase modulation unit is located overlaps with a rear focal plane of the imaging lens group; 22. The objective lens module according to claim 18, wherein the objective lens module is a lens module having a first surface and a second surface.

23. the phase modulation unit includes a spiral phase plate; 22. The objective lens module according to claim 18, wherein the objective lens module is a lens module having a first surface and a second surface.

24. and a first adjustment mechanism connected to the phase modulation unit and configured to change the position of the phase modulation unit within the plane in which the phase modulation unit is located based on a user's operation so that the center of the phase modulation unit overlaps with an image of the light source in the plane in which the phase modulation unit is located or is shifted from the image of the light source in the plane in which the phase modulation unit is located.

24. The objective lens module according to claim 23.

25. a second adjustment mechanism connected to the phase modulation unit and configured to change a position of the phase modulation unit in the optical axis direction of the objective lens module based on a user's operation; 22. The objective lens module according to claim 18, wherein the objective lens module is a lens module having a first surface and a second surface.

26. a light source configured to provide a light beam that is irradiated onto the sample; an external module having a connection portion connectable to the objective lens; wherein the external module further comprises a phase modulation unit; When the external module is connected to the objective lens through the connection part, the phase modulation unit is configured to modulate the light beam transmitted through the objective lens to form a desired sample image on an image plane of an objective lens module having the objective lens, wherein a plane where the phase modulation unit is located is conjugate with a plane where the light source is located, and no lens or lens group performing a Fourier transform is introduced into the optical path at least between the plane where the phase modulation unit is located and the image plane of the objective lens module. A combination of elements characterized by:

27. The phase modulation unit includes a spiral phase plate, and the external module includes: The external module further includes a first adjustment mechanism connected to the phase modulation unit and configured to change the position of the phase modulation unit within the plane in which the phase modulation unit is located based on a user's operation so that, when the external module is connected to an objective lens via the connection portion, the center of the phase modulation unit overlaps with an image of the light source in the plane in which the phase modulation unit is located or is shifted from an image of the light source in the plane in which the phase modulation unit is located.

27. The combination of claim 26.

28. The external module is a second adjustment mechanism connected to the phase modulation unit and configured to change a position of the phase modulation unit in the optical axis direction of the objective lens based on a user's operation; 28. A combination according to claim 26 or 27.

29. When the external module is connected to the objective lens through the connection part, the plane where the phase modulation unit is located overlaps with the back focal plane of the objective lens; 28. A combination according to claim 26 or 27.

30. This is applied to the combination according to any one of claims 26 to 29, wherein the external module includes a housing for accommodating the phase modulation unit, and the housing is provided with the connection portion. An external module characterized by:

31. Housing and an imaging lens group provided inside the housing and configured to receive light rays transmitted through an objective lens and perform a second or subsequent imaging of the sample, the objective lens being configured to receive light rays irradiated onto the sample from a light source and transmitted through the sample and perform a first imaging of the sample; and a phase modulation unit disposed within the housing and configured to modulate the light beam transmitted through the imaging lens group to form a desired sample image on an imaging plane of the external imaging module; where: The plane where the phase modulation unit is located and the plane where the light source is located are a pair of conjugate planes, and no lens or lens group performing a Fourier transform is introduced into the optical path between at least the plane where the phase modulation unit is located and the image plane of the external imaging module. An external imaging module characterized by:

32. The housing is provided with a connection portion, and the connection portion is connectable to an imaging port of a microscope.

32. The external imaging module of claim 31 .

33. a photosensitive element, the photosensitive surface of which overlaps with the imaging surface of the external imaging module; 33. The external imaging module of claim 32.

34. a light-passing hole is opened in the housing, and the light-passing hole extends from one end of the housing along the optical axis direction of the external imaging module, and the imaging lens group and the phase modulation unit are both connected to the hole wall of the light-passing hole; 32. The external imaging module of claim 31 .

35. the housing includes a first housing and a second housing that are detachably connected, wherein the imaging lens group is provided inside the first housing, and the phase modulation unit is provided inside the second housing; 32. The external imaging module of claim 31 .

36. a plane on which the phase modulation unit is located overlaps with a rear focal plane of the imaging lens group; 36. The external imaging module according to claim 31, wherein the external imaging module is a module having a plurality of lenses.

37. the phase modulation unit includes a spiral phase plate; 36. The external imaging module according to claim 31, wherein the external imaging module is a module having a plurality of lenses.

38. and a first adjustment mechanism connected to the phase modulation unit and configured to change the position of the phase modulation unit within the plane in which the phase modulation unit is located based on a user's operation so that the center of the phase modulation unit overlaps with an image of the light source in the plane in which the phase modulation unit is located or is shifted from the image of the light source in the plane in which the phase modulation unit is located.

38. The external imaging module of claim 37.

39. a second adjustment mechanism connected to the phase modulation unit and configured to change a position of the phase modulation unit in the optical axis direction of the external imaging module based on a user's operation; 36. The external imaging module according to claim 31, wherein the external imaging module is a module having a plurality of lenses.

40. A microscope comprising: a light source adapted to provide a light beam for illumination of a sample; and an external imaging module according to any one of claims 31 to 39. A combination of elements characterized by:

Images