Lensless digital holographic microscope

Abstract

The invention discloses a lensless digital holographic microscope. The lensless digital holographic microscope comprises a base assembly, a camera assembly, a first prism and a plane mirror assembly, the base assembly comprises a platform for placing a to-be-tested sample and a bracket positioned above the platform; the camera assembly comprises a camera, and the camera is located above the platform; the first prism is positioned below the camera and is fixedly arranged relative to the bracket; the plane mirror assembly is located at one side of the light-emitting hole of the first prism; the plane mirror assembly comprises a plane mirror, and the plane mirror is connected with the adjusting assembly; the adjusting assembly is used for adjusting the plane mirror, so that the plane where the plane mirror is located is obliquely arranged relative to the vertical direction, and the centers of the two light beams deviate from each other while the two light beams which are transmitted and reflected by the first prism and then are emitted to the camera direction coincide. According to the scheme, an eyepiece and an objective lens are omitted, when sample information is collected, focusing of the microscope does not need to be adjusted, and operability and flexibility are more obvious when the microscope is used.

Description

Technical Field

[0001] The present invention relates to the technical field of optical imaging equipment, and more specifically, to a lens-free digital holographic microscope. Background Art

[0002] As an advanced microscopic imaging technology, Digital Holographic Microscopy (DHM) has made significant progress in many fields in recent years. DHM mainly uses the principle of interference to record the optical information of the sample and reconstruct the image using computer algorithms to achieve high-resolution three-dimensional microscopic observation of the sample. It can provide amplitude information, capture phase information, and achieve real-time imaging. It is very effective for research that requires continuous monitoring of the changing process. On the other hand, since it does not directly contact the sample, DHM is very suitable for non-destructive testing of fragile or sensitive samples, and plays an important role in the study of cell structure, tissue composition and dynamic behavior of living cells; it is also suitable for microstructure analysis, including surface morphology, internal defect detection and characterization of nanoscale features. In the process of industrial development, it can provide efficient quality control means to help identify potential problems in the production process and ensure product quality. With its unique advantages and technical characteristics, DHM plays an increasingly important role in scientific research and technological development, and with the advancement of technology and the growth of market demand, it is expected to continue to maintain a good development trend in the next few years.

[0003] In the existing DHM technology, it mainly relies on the combination of coaxial interference plus objective lens and eyepiece, and uses the camera to record the optical information of the sample and then form an image, but there are still some technical structural defects, as follows:

[0004] (1) Although the combination of objective lens and eyepiece can improve the imaging magnification of the sample, it will limit the field of view of a single image acquisition, making it difficult to achieve both high resolution and a large field of view. It is necessary to change the combination of objective lens and eyepiece multiple times and perform multiple measurements to achieve the relevant goals.

[0005] (2) It is also constrained by the different combinations of objective lenses and eyepieces. Each time the objective lens or eyepiece is changed, the imaging focal length of the lens changes, and the position of the sample or lens group needs to be manually adjusted so that the sample can be located at the focal length position of the lens group, so that the image can be focused. The change of the relevant hardware position still takes time, which also restricts the application of DHM in industrial production.

[0006] (3) The interference optical path of the microscope itself is compact. After the objective lens and eyepiece structure are introduced, in order to adapt to the focal length of the lens group, the related hardware structure will become bulky. At the same time, the optical diffraction limit and the complexity of the structure will cause the DHM to be highly sensitive to environmental disturbances. It needs to be placed on a rigid or hard platform for relevant measurements. The vibration in the normal environment will cause noise to be introduced into the optical information, thereby affecting the imaging quality. Summary of the invention

[0007] In view of at least some problems in the prior art, the present invention provides a lensless digital holographic microscope, which uses a lensless digital holographic microscope without an objective lens and an eyepiece, simplifies the structure of the microscope, and improves the imaging quality of the image.

[0008] In order to achieve the above object, the technical solution provided by the present invention is:

[0009] A lensless digital holographic microscope, comprising:

[0010] A base assembly, comprising a platform for placing a sample to be tested and a bracket located above the platform;

[0011] Also includes:

[0012] A camera assembly, including a camera, wherein the camera is located above the platform;

[0013] A first prism is located below the camera and fixed relative to the bracket;

[0014] A plane mirror assembly is located on one side of the light exit hole of the first prism; the plane mirror assembly includes a plane mirror, and the plane mirror is connected to an adjustment assembly; the adjustment assembly is used to adjust the plane mirror so that the plane where the plane mirror is located is tilted relative to the vertical direction, so that the two light beams transmitted and reflected by the first prism and emitted in the direction of the camera overlap, and the centers of the two light beams are also offset from each other.

[0015] In this scheme, the paraxial interference structure formed by the tilted plane mirror eliminates the need for an eyepiece and an objective lens, and when collecting sample information, there is no need to adjust the focus of the microscope, making it more operable and flexible to use. The use of a lens-free structure can free the microscope structure of this scheme from the constraints of the optical diffraction limit. Based on the collected sample optical image, it is easier to obtain ultra-high resolution with nanometer precision in subsequent optimization, improve image quality, and thus improve detection accuracy.

[0016] As a further improvement, the adjustment assembly includes a plane mirror bracket connected to the bracket, and both ends of the plane mirror are connected to the plane mirror bracket through a first adjuster and a second adjuster, so that the inclination of the plane mirror is adjusted by the first adjuster and the second adjuster.

[0017] As a further improvement, a light source access end is provided on one side of the light inlet of the first prism, and the light source access end includes a first light source access end, and an optical fiber interface is provided on the first light source access end, and the optical fiber interface is used to access an optical fiber to generate a light beam a. The first light source access end can be connected to an optical fiber coupler to improve the quality of camera image acquisition information.

[0018] As a further improvement, the light source access end includes a second light source access end and a third light source access end; a second prism is arranged on one side of the light inlet of the first prism, the second light source access end and the third light source access end are respectively located on different sides of the light inlet of the second prism, and the second prism is used to combine the light sources connected to the second light source access end and the third light source access end into a light beam a. The second light source access end and the third light source access end can be connected to a laser light source, and the two laser light sources are combined through the second prism, which not only improves the quality effect of image acquisition, but also can greatly reduce costs.

[0019] As a further improvement, the third light source access end includes an adjustment frame connected to the bracket and an adjuster connected to the adjustment frame; the structure of the second light source access end is consistent with the structure of the third light source access end. The adjustment frame and the adjuster are provided for straightening the laser light source.

[0020] As a further improvement, a light hole component is provided at the light source outlet of the light source access end, and the light hole component is used to change the spot size of the light beam a.

[0021] As a further improvement, the light-through hole assembly includes a fixing frame and an adjustment plate detachably connected to the fixing frame, the fixing frame is provided with a second light-through hole, and the adjustment plate is provided with a first light-through hole. Different adjustment plates are provided with second light-through holes of different sizes, and when the size of the second light-through hole needs to be changed, the adjustment plate can be replaced, which is very convenient.

[0022] As a further improvement, the aperture of the first light-transmitting hole is larger than the photosensitizing area of ​​the camera.

[0023] As a further improvement, the camera is arranged in the overlapping area of ​​the light beam a4 and the light beam a5.

[0024] As a further improvement, the camera assembly further comprises a camera support for fixing the camera, a first slider and a second slider for adjusting the position of the camera, wherein the first slider and the second slider are located between the camera support and the support. The position of the camera is adjusted by the first slider and the second slider so that the camera can be in the overlapping area of ​​the light beam a4 and the light beam a5.

[0025] Other technical problems that can be solved by the lensless digital holographic microscope of the present invention, other technical features included in the technical solution, and the advantages brought by these technical features will be further described in detail in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the microscope structure of Example 1;

[0027] Figure 2 This is a schematic diagram of the explosion structure of the microscope in Example 1;

[0028] Figure 3 This is a schematic diagram of the explosion structure of the microscope in Example 1 from another angle;

[0029] Figure 4 This is a schematic diagram of the structure of the light-through hole assembly in Example 1;

[0030] Figure 5 Schematic diagram of the microscope imaging light path in Example 1;

[0031] Figure 6 This is a schematic diagram of the microscope structure of Example 2;

[0032] Figure 7 This is a schematic diagram of the explosion structure of the microscope in Example 2;

[0033] Figure 8 This is a schematic diagram of the explosion structure of the microscope in Example 2 from another angle;

[0034] Fig. 9 This is a schematic diagram of the structure of the light-through hole assembly in Example 2;

[0035] Fig.10 Schematic diagram of the microscope imaging light path in Example 2;

[0036] Fig.11 The sample image collected by the camera;

[0037] Fig.12 This is the spectrum separation diagram of the collected samples.

[0038] Description of labels:

[0039] 1. Sample; 2. Column; 3. Main slider; 4. Bracket;

[0040] 5. Camera; 501. Camera support; 502. First slider; 503. Second slider;

[0041] 6. First prism;

[0042] 7. Plane mirror assembly; 701. Plane mirror; 702. Plane mirror bracket; 703. First regulator; 704. Second regulator;

[0043] 8. Light-through hole assembly; 801. Adjustment plate; 802. First light-through hole; 803. Second light-through hole;

[0044] 9. First light source access terminal; 901. Optical fiber interface;

[0045] 10. Second prism; 11. Second light source access terminal; 12. Third light source access terminal; 1201. Fixer; 1202. Adjustment frame; 1203. Third adjuster; 1204. Fourth adjuster; 1205. Fifth adjuster. DETAILED DESCRIPTION

[0046] In order to further understand the content of the present invention, the present invention is described in detail in conjunction with the accompanying drawings and embodiments.

[0047] The structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with this technology. They are not used to limit the conditions under which the present invention can be implemented, and therefore have no substantive technical significance. Any structural modification, change in proportion or adjustment of size, without affecting the effects and purposes that can be achieved by the present invention, should still fall within the scope of the technical contents disclosed by the present invention.

[0048] At the same time, the terms such as "upper", "lower", "left", "right", "middle" etc. cited in this specification are only for the convenience of description, and are not used to limit the scope of implementation. Changes or adjustments in their relative relationships should also be regarded as the scope of implementation of the present invention without substantially changing the technical content. In addition, in addition to being used to indicate orientation or positional relationships, some of the above terms may also be used to express other meanings. For example, the term "upper" may also be used to indicate a certain dependency or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in this application can be understood according to the specific circumstances.

[0049] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so as to describe the embodiments of the present application described herein.

[0050] Example 1

[0051] Combination Figure 1-5 As shown, this embodiment provides a lens-free digital holographic microscope, including a base assembly, a camera assembly, a first prism 6 and a plane mirror assembly 7.

[0052] Specifically, the base assembly includes a platform for placing the sample 1 to be tested and a bracket 4 located above the platform. In this solution, a column 2 is installed on the platform, and the column 2 is vertically arranged on the platform. The column 2 also has a slide rail, and a main slider 3 is installed on the slide rail. The main slider 3 is fixedly connected to the bracket 4. Through the cooperation and connection between the slide rail and the main slider 3, the main slider 3 can adjust the position of the bracket 4 up and down when moving along the slide rail, thereby adjusting the up and down positions of the components of the bracket 4.

[0053] In order to position the main slider 3, a locking member, such as a locking nut, is also connected to the main slider 3. When the main slider 3 moves to a desired position along the slide rail, it is locked and positioned at the position by the locking member.

[0054] The camera assembly includes a camera 5, which is located above the platform. When a sample 1 is placed on the platform, the camera 5 is used to capture an image of the sample 1. In a specific case, the camera 5 uses a CMOS camera, which has a high imaging speed and can be suitable for rapidly changing scenes.

[0055] Regarding the camera assembly, it also includes a camera bracket 501 for fixing the camera 5, a first slider 502 and a second slider 503 for adjusting the position of the camera 5, and the first slider 502 and the second slider 503 are located between the camera bracket 501 and the bracket 4. Figure 2 and Figure 3 As shown, the first slider 502 is connected to the bracket 4, the second slider 503 is connected to the first slider 502, and the second slider 503 is connected to the camera bracket 501. Figure 1 When the first slider 502 moves, the camera support 501 and the camera 5 move left and right, and when the second slider 503 moves, the camera support 501 and the camera 5 move forward and backward. The camera 5 is adjusted by moving the first slider 502 and the second slider 503.

[0056] The first prism 6 is located below the camera 5 and fixed relative to the bracket 4. The plane mirror assembly 7 is located at one side of the light exit hole of the first prism 6; the plane mirror assembly 7 includes a plane mirror 701, and the plane mirror 701 is connected to the adjustment assembly; the adjustment assembly is used to adjust the plane mirror 701 so that the plane where the plane mirror 701 is located is tilted relative to the vertical direction.

[0057] Regarding the first prism 6, the first prism 6 adopts a dichroic prism, and the plane where the plane mirror 701 is located is tilted relative to the vertical direction, so that the two light beams transmitted and reflected by the first prism 6 toward the camera 5 have overlapping areas, and the centers of the two light beams are also deviated from each other.

[0058] Specifically combined Figure 5For illustration, the light beam entering the first prism 6 is light beam a, which is the light beam generated by the light source. Light beam a is split by the first prism 6 into light beam a1 and light beam a2. Light beam a1 is the reflected light of the first prism 6 and is emitted to the sample 1, and light beam a2 is the transmitted light of the first prism 6. The transmitted light beam a2 is emitted to the plane mirror 701, and is reflected by the plane mirror 701 to form light beam a3. Light beam a3 is emitted to the first prism 6 and then reflected by the first prism 6 to form light beam a4, and then emitted to the camera 5; light beam a1 is emitted toward the direction of the sample 1 and is emitted to the first prism 6 after being reflected by the sample 1, and then is transmitted by the first prism 6 to form light beam a5 and emitted to the camera 5. In this scheme, the plane where the plane mirror 701 is located is tilted relative to the vertical direction, so that light beams a4 and a5 overlap, and the center of light beam a4 is set away from light beam a5.

[0059] In this solution, the camera 5 is set in the overlapping area of ​​the light beam a4 and the light beam a5 to collect information of the sample 1.

[0060] The lensless digital holographic microscope in this scheme eliminates the objective lens and eyepiece in the microscope, and structurally slims down the microscope structure to make it more compact.

[0061] When the lensless digital holographic microscope in this embodiment is used, the light source is first turned on, and the microscope is connected to a host computer, such as a computer, so that the image information collected by the camera 5 can be observed in real time on the computer. Then, the tilt angle of the plane mirror 701 is adjusted so that the camera 5 can collect visible sample feature information such as Fig.11 As shown, observe the corresponding spectrum separation diagram in the computer at the same time. When the spectrum appears as Fig.12 When there are three separated light spots as shown, it means that the angle adjustment of the plane mirror 701 is completed. The spectrum separation diagram can be obtained by conventional holo algorithm, which will not be described here.

[0062] By adjusting the plane mirror 701, the light beams a4 and a5 are no longer coaxial, and the spot centers of the light beams a4 and a5 are offset, so that the camera can collect sufficient optical phase deviation information to obtain the corresponding spectrum separation diagram.

[0063] according to Fig.12 as shown in Fig.12 Taking the viewing direction in as an example, there are three separated light spots in the vertical direction on the spectrum separation diagram. Usually, the bright spot in the middle is the 0-level light spot, which contains the light source information and is generally not in the selection range. The upper and lower spots centered on the 0-level light spot are the +1 and -1-level spots respectively. By adjusting the size of the selected light spot and matching the wavelength of the light source, the microscope in this scheme is not constrained by a small depth of field, and the maximum depth of field range can reach 1 / 2 of the wavelength of the light source.

[0064] In this solution, the paraxial interference structure formed by the plane mirror 701 eliminates the eyepiece and the objective lens, and when collecting sample information, there is no need to adjust the focus of the microscope, and the operability and flexibility during use are more obvious. The use of a lens-free structure can free the microscope structure of this solution from the constraints of the optical diffraction limit. According to the collected sample optical image, it is easier to obtain ultra-high resolution with nanometer precision in subsequent optimization, improve image quality, and thus improve detection accuracy.

[0065] As a preferred embodiment, the adjustment assembly includes a plane mirror bracket 702 connected to the bracket 4, and both ends of the plane mirror 701 are connected to the plane mirror bracket 702 through a first adjuster 703 and a second adjuster 704. Figure 2 and Figure 3 As shown, the plane mirror bracket 702 is fixed relative to the bracket 4, and the first adjuster 703 and the second adjuster 704 can be adjustment bolts. By rotating the first adjuster 703 and the second adjuster 704, the positions of the two ends of the plane mirror 701 are adjusted, so that the plane where the plane mirror 701 is located is tilted relative to the vertical direction.

[0066] In this embodiment, a light source access end is provided on one side of the light inlet of the first prism 6, and the light source access end includes a first light source access end 9. Specifically, the first light source access end 9 can be connected to a fiber coupler to input a coupled light source. In this solution, a fiber interface 901 is provided on the first light source access end 9, and the fiber interface 901 is used to access an optical fiber, thereby generating a light beam a. The light beam a generated by the fiber coupler has a more stable optical information quality, which helps to improve the image acquisition information quality of the camera 5.

[0067] Preferably, a light hole component 8 is provided at the light source outlet of the light source access end, and the light hole component 8 is used to change the spot size of the light beam a. Figure 4 As shown, the light hole assembly 8 includes a fixing frame and an adjustment plate 801 detachably connected to the fixing frame, a second light hole 803 is formed on the fixing frame, and a first light hole 802 is formed on the adjustment plate 801. Figure 5 As shown, the light source at the light source access end generates a light beam A, which passes through the second light hole 803 and the first light hole 802 in sequence to become a light beam a. The light beam a and the light beam A only differ in spot size.

[0068] The aperture of the first light hole 802 is larger than the photosensitive area of ​​the camera 5. The aperture of the first light hole 802 corresponds to the spot size of the light beam a. The aperture of the first light hole 802 is changed accordingly according to the photosensitive area of ​​the camera 5. In the specific operation process, there are usually multiple adjustment plates 801, each of which is provided with a second light hole 803 of different sizes. When the size of the second light hole 803 needs to be changed, the adjustment plate 801 can be replaced.

[0069] Example 2

[0070] Combination Figure 6-10 As shown, this embodiment provides a lensless digital holographic microscope. The structure and arrangement of the base assembly, camera assembly, first prism 6 and plane mirror assembly 7 in the lensless digital holographic microscope structure in this embodiment are consistent with those in Embodiment 1, and will not be repeated here.

[0071] Specifically in this embodiment, the light source access end includes a second light source access end 11 and a third light source access end 12; a second prism 10 is arranged on one side of the light inlet of the first prism 6, and the second light source access end 11 and the third light source access end 12 are respectively located on different light inlet sides of the second prism 10, and the second prism 10 is used to combine the light sources connected to the second light source access end 11 and the third light source access end 12 to form a light beam a.

[0072] In the present solution, two light source access terminals are used, namely, the second light source access terminal 11 and the third light source access terminal 12. Compared with the first light source access terminal 9 in Example 1 being connected to the optical fiber coupler, the second light source access terminal 11 and the third light source access terminal 12 in the present embodiment can be connected to an ordinary laser light source, such as a laser pen, etc., and the light beam a is finally generated by coupling two laser light sources, which can also achieve the quality effect of image acquisition in Example 1 and can also greatly reduce the cost.

[0073] Combination Fig. 9 As shown, a light hole component 8 is provided at the light source outlet of the second light source access end 11 and the third light source access end 12 , and the structure of the light hole component 8 is consistent with that in the first embodiment.

[0074] Combination Fig.10 As shown, the light source connected to the second light source access end 11 generates a light beam A0, and the light source connected to the third light source access end 12 generates a light beam A0'. The light beam A0 forms a light beam a0 after passing through the light hole assembly 8, and the light beam A0' forms a light beam a0' after passing through the light hole assembly 8. The light beams a0 and a0' are combined by the second prism 10 to form a light beam a, and then the light beam a is emitted to the first prism 6, and then the path of the light beam is consistent with that in Example 1.

[0075] Combination Figure 7 and Figure 8 As shown, the structure of the second light source access terminal 11 is consistent with that of the third light source access terminal 12 , and the structure of the third light source access terminal 12 is specifically described.

[0076] The third light source access end 12 includes an adjustment frame 1202 connected to the bracket 4 and an adjuster connected to the adjustment frame 1202. Specifically, the third light source access end 12 also includes a fixing plate, which is fixedly arranged relative to the bracket 4, and a fixture 1201 is installed on the fixing plate. The fixture 1201 is also connected to the adjustment frame 1202, and the adjustment frame 1202 is connected to the fixing plate. The adjustment frame 1202 is also connected to the third adjuster 1203, the fourth adjuster 1204 and the fifth adjuster 1205. In one case, the fixture 1201 is used to fix the laser light source, and the third adjuster 1203, the fourth adjuster 1204 and the fifth adjuster 1205 are adjustment bolts. When the bolts are adjusted, the adjustment frame 1202 is adjusted, and the adjustment frame 1202 drives the fixture 1201 to change position, thereby changing the angle of the laser light source, so as to be used to straighten the laser light source, so that the second prism 10 combines the light sources connected to the second light source access end 11 and the third light source access end 12.

[0077] The terms "installed", "set", "provided with", and "connected" referred to herein should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection, or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, elements, or components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0078] The present invention and its embodiments are described schematically above, and the description is not restrictive. The drawings show only one embodiment of the present invention, and the actual structure is not limited thereto. Therefore, if a person skilled in the art is inspired by it and designs a structural method and an embodiment similar to the technical solution without creativity without departing from the purpose of the invention, they shall all fall within the protection scope of the present invention.

Claims

1. A lensless digital holographic microscope, comprising: A base assembly, comprising a platform for placing a sample to be tested (1) and a support (4) located above the platform; It is characterized by further comprising: A camera assembly, comprising a camera (5), wherein the camera (5) is located above the platform; A first prism (6) is located below the camera (5) and is fixedly arranged relative to the bracket (4); A plane mirror assembly (7) is located on one side of the light exit hole of the first prism (6); the plane mirror assembly (7) comprises a plane mirror (701), and the plane mirror (701) is connected to an adjustment assembly; the adjustment assembly is used to adjust the plane mirror (701) so that the plane where the plane mirror (701) is located is tilted relative to the vertical direction, so that two light beams transmitted and reflected by the first prism (6) and emitted in the direction of the camera (5) overlap, and the centers of the two light beams are also offset from each other.

2. The lensless digital holographic microscope according to claim 1, characterized in that: The adjustment component comprises a plane mirror bracket (702) connected to the bracket (4), and two ends of the plane mirror (701) are connected to the plane mirror bracket (702) via a first adjuster (703) and a second adjuster (704).

3. The lensless digital holographic microscope according to claim 1, characterized in that: A light source access end is provided on one side of the light inlet hole of the first prism (6), the light source access end comprising a first light source access end (9), an optical fiber interface (901) is provided on the first light source access end (9), and the optical fiber interface (901) is used to access an optical fiber, thereby generating a light beam a.

4. The lensless digital holographic microscope according to claim 1, characterized in that: The light source access end comprises a second light source access end (11) and a third light source access end (12); a second prism (10) is arranged on one side of the light inlet of the first prism (6); the second light source access end (11) and the third light source access end (12) are respectively located on different sides of the light inlet of the second prism (10); and the second prism (10) is used to combine the light sources connected to the second light source access end (11) and the third light source access end (12) into a light beam a.

5. The lensless digital holographic microscope according to claim 4, characterized in that: The third light source access end (12) comprises an adjustment frame (1202) connected to the bracket (4) and an adjuster connected to the adjustment frame (1202); The structure of the second light source access end (11) is consistent with the structure of the third light source access end (12).

6. The lensless digital holographic microscope according to any one of claims 3 to 5, characterized in that: A light through hole component (8) is arranged at the light source outlet of the light source access end, and the light through hole component (8) is used to change the spot size of the light beam a.

7. The lensless digital holographic microscope according to claim 6, characterized in that: The light-through hole assembly (8) comprises a fixing frame and an adjustment plate (801) detachably connected to the fixing frame, the fixing frame is provided with a second light-through hole (803), and the adjustment plate (801) is provided with a first light-through hole (802).

8. The lensless digital holographic microscope according to claim 7, characterized in that: The aperture of the first light-transmitting hole (802) is larger than the light-sensitive area of ​​the camera (5).

9. The lensless digital holographic microscope according to claim 1, characterized in that: The camera (5) is arranged in the overlapping area of ​​the light beam a4 and the light beam a5.

10. The lensless digital holographic microscope according to claim 9, characterized in that: The camera assembly further comprises a camera support (501) for fixing the camera (5), a first slider (502) and a second slider (503) for adjusting the position of the camera (5), wherein the first slider (502) and the second slider (503) are located between the camera support (501) and the support (4).

Images