Underwater Microscopic Observation Instrument

Abstract

This disclosure relates to the field of underwater optical imaging technology, specifically providing an underwater microscopic observation instrument, including a light source chamber and an imaging chamber connected by a focusing mount. The imaging chamber contains an imaging unit for imaging underwater targets between the light source chamber and the imaging chamber. The light source chamber includes a first housing, optical components, and a driving mechanism. The optical components include a laser and a dimming assembly. The laser outputs a pulsed laser beam. The dimming assembly includes a reflector, a conical mirror, and a lens arranged sequentially along the optical axis of the pulsed laser beam. The conical reflector of the mirror reflects the pulsed laser beam, forming a first reflected beam. The first reflected beam is reflected by the inner surface of the reflector to form a conical second reflected beam, which passes through the lens and converges on the optical axis to form an illumination layer. The driving mechanism is used to adjust the position and thickness of the illumination layer to improve the clarity of the underwater imaging of the target by the imaging chamber.

Description

Technical Field

[0001] At least one embodiment of this disclosure relates to the field of underwater optical imaging technology, and more specifically, to an underwater microscopic observation instrument. Background Technology

[0002] Marine plankton observation is an important component of marine scientific research, playing a crucial role in understanding the structure and function of marine ecosystems and predicting and responding to environmental changes. Marine plankton, including phytoplankton, zooplankton, and bacteria, is a vital part of marine ecosystems. Extensive scientific research, emergency monitoring, and assessment of their impact on marine ecosystems rely on the rapid acquisition of in-situ information on plankton. Changes in their taxonomic composition, abundance, and particle size distribution can reflect changes in ecosystem structure and function, marine biological resource output, and ecosystem health.

[0003] Traditional methods for observing marine planktonic organisms typically involve collecting water samples and then observing and counting them under a microscope in a laboratory. However, this method has many limitations, such as low sampling frequency, limited range, and susceptibility to human error. With technological advancements, modern marine planktonic observation techniques are constantly improving. Currently, commonly used technologies include remote sensing, automated observation systems, and underwater robots. These technologies enable high-frequency, large-area, and continuous observation of marine planktonic organisms, significantly improving observation efficiency and accuracy.

[0004] Underwater microscopy instruments are crucial for studying plankton. Since dark-field imaging yields higher contrast images, microscopy instruments with dark-field illumination capabilities are currently a research focus. Among related technologies, LED dark-field illumination is widely used, primarily due to its lower cost and mature technology. However, the beam divergence angle of LED dark-field illumination is difficult to compress, resulting in a thicker light layer. This leads to light scattering and light pollution, especially in turbid water conditions, severely impacting image clarity. Known LD laser illumination technologies use multiple semiconductor lasers to illuminate from all sides towards the center, resulting in a large light source and equipment size, and poor light field uniformity. Therefore, improving the imaging clarity of microscopy instruments under underwater illumination and their adaptability to different water conditions are urgent technical challenges. Summary of the Invention

[0005] In view of the above problems, this disclosure provides an underwater microscopic observation instrument that can produce an underwater light layer with a small thickness and uniform intensity, thereby improving the imaging effect, and can be flexibly adjusted under different water conditions.

[0006] To achieve the above objectives, this disclosure provides an underwater microscopic observation instrument, comprising: an imaging chamber, wherein an imaging unit is provided inside the imaging chamber for imaging underwater observation targets; and a light source chamber, coaxially connected to the imaging chamber via a focusing mount, wherein the observation target is located between the light source chamber and the imaging chamber, and comprising: a first housing; an optical assembly, installed within the first housing, comprising: a laser adapted to output a pulsed laser beam; and a dimming assembly comprising a reflector, a conical mirror, and a lens arranged sequentially along the optical axis of the pulsed laser beam; wherein the reflector is configured to reflect the pulsed laser beam using its conical reflective surface to form a first reflected beam; The first reflected beam is reflected by the inner surface of the reflector cup to form a conical second reflected beam. The second reflected beam passes through the lens and converges on the optical axis to form an illumination layer. A drive mechanism is installed inside the first housing and includes: a first drive assembly configured to drive the reflector to move along the optical axis to adjust the position of the illumination layer to near the observation target; and a second drive assembly configured to drive the lens to move along the optical axis to change the incident angle at which the second reflected beam converges, such that the thickness of the illumination layer is less than or equal to the depth of field of the imaging unit, thereby improving the clarity of the underwater imaging of the observation target by the imaging chamber.

[0007] In one illustrative embodiment, the optical component further includes a beam expander arranged between the laser and the dimming component along the optical axis, which is adapted to change the diameter of the pulsed laser beam to adjust the thickness of the illumination layer.

[0008] In one illustrative embodiment, the drive mechanism further includes a third drive component;

[0009] The aforementioned beam expander includes an input lens and an output lens, and the aforementioned third driving component is configured to change the distance between the input lens and the output lens to adjust the beam expansion magnification of the beam expander.

[0010] In one illustrative embodiment, the driving mechanism further includes a fourth driving component adapted to drive the dimming component to move along the optical axis direction to adjust the position of the illumination layer.

[0011] In one illustrative embodiment, the inner surface of the reflector cup is a quadratic surface, so that the first driving component adjusts the incident angle of the convergence of the second reflected beam during the process of driving the reflector to move.

[0012] In one illustrative embodiment, the laser is a three-primary-color combined white light pulse collimated laser, and is configured such that the power of the three primary colors is adjustable to change the color of the output beam.

[0013] In one illustrative embodiment, the focusing mount includes: a plurality of connecting screws, one end of which is connected to the first housing; and a focusing ring, rotatably mounted on the end of the imaging chamber facing the light source chamber, the other end of which is threadedly connected to the focusing ring; preferably, a cable suitable for electrically connecting the light source chamber and the imaging chamber passes through at least one of the connecting screws.

[0014] In one illustrative embodiment, a liquid-filled chamber is also included, installed at one end of the imaging chamber near the light source chamber, wherein the scattering rate of the liquid inside the liquid-filled chamber is lower than that of the external medium.

[0015] In one illustrative embodiment, the imaging unit includes a telecentric lens and an imaging camera. The telecentric lens is adapted to receive and focus a light beam passing through the observed target for imaging by the imaging camera.

[0016] In one illustrative embodiment, the imaging chamber further includes a control storage unit configured to control the synchronous operation of the light source chamber and the imaging chamber, and to store the generated images of the observed target.

[0017] The underwater microscopic observation instrument disclosed herein uses a laser to emit a pulsed laser beam. Upon reaching a reflector, the beam is reflected into a first reflected beam that travels 360 degrees circumferentially. This first reflected beam is then reflected by a reflector cup to form a conical second reflected beam. Finally, the beam is converged by a lens onto the extension of the optical axis, forming an illumination layer. This 360-degree circumferential illumination layer has a relatively small thickness, resulting in clearer underwater imaging of the target by the imaging unit, and more uniform light intensity, effectively reducing the impact of light scattering during propagation in water. A first driving component moves the reflector to adjust the illumination layer to be near the target. A second driving component moves the lens to adjust the incident angle when the second reflected beam converges, thereby changing the thickness of the illumination layer and coordinating with the depth of field of the imaging unit to achieve clearer imaging. Attached Figure Description

[0018] The foregoing contents, as well as other objects, features, and advantages of this disclosure, will become clearer from the following description of embodiments with reference to the accompanying drawings, in which:

[0019] Figure 1 This is a simplified structural diagram of the underwater microscopic observation instrument provided in this disclosure;

[0020] Figure 2 This is a diagram of the internal structure of the underwater microscopic observation instrument provided in this disclosure;

[0021] Figure 3 yes Figure 2The illustrated exemplary embodiment is a schematic diagram of the internal optical path during operation.

[0022] Figure 4 This is a schematic diagram of the illumination layer generated by the light source chamber in one embodiment provided in this disclosure;

[0023] Figure 5 This is a schematic diagram of the illumination layer generated by the light source chamber in another embodiment provided in this disclosure;

[0024] Figure 6 This is a physical image comparing the imaging effects of the underwater microscopic observation instrument provided in this disclosure.

[0025] The meanings of the reference numerals in the above figures are as follows:

[0026] 1. Light source compartment;

[0027] 10. Laser;

[0028] 11. Reflector;

[0029] 12. Reflector;

[0030] 13. Lens;

[0031] 14. Beam expander;

[0032] 15. First shell;

[0033] 2. Imaging chamber;

[0034] 21. Telecentric lens;

[0035] 22. Imaging camera;

[0036] 23. Control storage unit;

[0037] 3. Power supply compartment;

[0038] 4. Liquid filling chamber;

[0039] 5. Focusing mount;

[0040] 51. Connecting screw;

[0041] 52. Focusing ring;

[0042] 100. First driving component;

[0043] 200. Second drive component;

[0044] 300. Third drive component;

[0045] 400. Fourth drive component. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of this disclosure clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings. The terminology used herein is merely for describing the specific embodiments and is not intended to limit the scope of this disclosure.

[0047] The terms “comprising,” “including,” etc., as used herein indicate the presence of the described features, steps, operations, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, or components. All terms used herein, including technical and scientific terms, have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification and not in an idealized or overly rigid way.

[0048] In this document, unless otherwise specified, directional terms such as “up,” “down,” “left,” “right,” “inner,” and “outer” are used to indicate orientation or positional relationships based on the accompanying drawings, and are used only for the convenience of describing this disclosure, and are not intended to indicate or imply that the device, element, or assembly referred to must have a specific orientation, or be constructed or operated in a specific orientation. It should be understood that when the absolute position of the described object changes, the relative positional relationships it represents may also change accordingly. Therefore, these directional terms should not be construed as limitations on this disclosure.

[0049] When using expressions such as "at least one of A, B, and C," the meaning should generally be interpreted according to the understanding of someone skilled in the art. For example, "a system having at least one of A, B, and C" should include, but is not limited to, systems having A alone, having B alone, having C alone, having A and B, having A and C, having B and C, and / or having A, B, and C. Similarly, when using expressions such as "at least one of A, B, or C," the meaning should generally be interpreted according to the understanding of someone skilled in the art. For example, "a system having at least one of A, B, or C" should include, but is not limited to, systems having A alone, having B alone, having C alone, having A and B, having A and C, having B and C, and / or having A, B, and C.

[0050] Figure 1 This is a simplified structural diagram of the underwater microscopic observation instrument provided in this disclosure. Figure 2 yes Figure 1 The internal structure plan view in the exemplary embodiment shown. Figure 3 yes Figure 1 The illustrated exemplary embodiment shows a schematic diagram of the optical path during operation.

[0051] An exemplary embodiment of this disclosure provides an underwater microscopic observation instrument, such as... Figures 1-2As shown, the system includes a light source chamber 1 and an imaging chamber 2. The imaging chamber 2 houses an imaging unit suitable for imaging underwater targets. The light source chamber 1 and the imaging chamber 2 are coaxially connected via a focusing mount 5, with the target located between them. The light source chamber 1 includes a first housing 15, optical components, and a drive mechanism. The optical components are installed within the first housing 15 and include a laser 10 and a dimming assembly. The laser 10 outputs a pulsed laser beam. The dimming assembly includes a reflector 11, a conical mirror 12, and a lens 13 arranged sequentially along the optical axis of the pulsed laser beam. The reflector 12 is configured to reflect the pulsed laser beam using its conical reflective surface to form a first reflected beam. The first reflected beam is reflected by the inner surface of the reflector 11 to form a conical second reflected beam. The second reflected beam passes through the lens 13 and converges onto the optical axis to form an illumination layer.

[0052] like Figure 3 As shown, the drive mechanism is installed within the first housing 15 and includes a first drive assembly 100 and a second drive assembly 200. The first drive assembly 100 is configured to drive the reflector 12 to move along the optical axis to adjust the position of the illumination layer to near the observation target. The second drive assembly 200 is configured to drive the lens 13 to move along the optical axis to change the incident angle of the convergence of the second reflected beam, such that the thickness of the illumination layer is less than or equal to the depth of field of the imaging unit, thereby improving the clarity of the underwater imaging of the observation target by the imaging chamber 2.

[0053] According to the underwater microscopic observation instrument of the above embodiment, the laser 10 emits a pulsed laser beam, which is reflected by the reflector 12 to form a first reflected beam that is emitted 360 degrees circumferentially. This first reflected beam is reflected by the reflector cup 11 to form a cone-shaped second reflected beam, which is finally converged by the lens 13 onto the extension line of the optical axis to form an illumination layer. The 360-degree circumferential illumination layer thus formed has a small thickness, making the underwater imaging of the observed target clearer and the light intensity more uniform, effectively reducing the impact of light scattering during propagation in water. The first driving component 100 drives the reflector 12 to move, adjusting the illumination layer to be near the observed target. The second driving component 200 drives the lens 13 to move, adjusting the incident angle when the second reflected beam converges, thereby changing the thickness of the illumination layer and thus coordinating with the depth of field of the imaging unit to achieve a better imaging effect. The underwater microscopic observation instrument of this disclosure is suitable for observing marine planktonic organisms such as phytoplankton, zooplankton, and bacteria in the ocean, and can quickly acquire information such as taxonomic composition, abundance, and particle size distribution of marine planktonic organisms, so as to conduct scientific research, emergency monitoring, and assessment of marine ecology.

[0054] According to embodiments of this disclosure, the first driving assembly 100 includes a first motor. The drive shaft of the first motor meshes with the housing of the reflector 12 via gears. The reflector 12 is connected to a guide hole formed on the housing via a guide post. The guide hole is shaped such that when the housing rotates with the drive shaft, the guide post slides along the sidewall of the guide hole, thereby driving the reflector 12 to move along the optical axis. Correspondingly, the principle by which the second driving assembly 200 drives the lens 13 to move is similar to the principle by which the first driving assembly 100 drives the reflector 12 to move, and will not be described in detail here.

[0055] According to an embodiment of this disclosure, the conical reflector 12 is attached to the light guide tube by means of a transparent glass cover, and the apex of the cone is located on the optical axis and faces the laser 10 to reflect the pulsed laser beam.

[0056] In one exemplary embodiment, the cone angle of the reflector 12 is 90° to minimize the loss of the pulsed laser beam. When the cone angle is greater than 90°, the pulsed laser beam will reflect too many times between the reflector 12 and the reflector cup 11, resulting in greater energy dissipation, and the incident angle at which the second reflected beam converges will be difficult to control. When the cone angle is less than 90°, a portion of the pulsed laser beam will not reach the inner surface of the reflector cup 11 after passing through the reflector 12, but will instead irradiate the first housing 15 or other components within the first housing 15, which may easily damage the equipment. Since the cone angle of the reflector 12 is 90°, during the process of the first driving assembly 100 driving the reflector 12 to move along the optical axis, the pulsed laser beam emitted by the laser 10 is reflected by the reflector 12 to form a first reflected beam that is emitted 360 degrees circumferentially and perpendicular to the optical axis.

[0057] For example, lens 13 may include, but is not limited to, a conventional convex lens, an aspherical convex lens, or a Fresnel lens.

[0058] In one exemplary embodiment, a laser pulse driver is provided in conjunction with the laser 10 to drive the laser 10 to output a pulsed laser beam.

[0059] In one exemplary embodiment, a light guide tube is provided between the laser 10 and the reflector 11, through which the pulsed laser beam enters the dimming assembly.

[0060] Specifically, the light guide tube is a hollow metal tube with threads formed on its outer surface, and the reflector cup 11 is connected to the light guide tube by the threads.

[0061] According to an embodiment of this disclosure, the reflector cup 11 is constructed as a hollow cylinder with its inner surface forming a reflective surface. The smaller end of the reflector cup 11 is close to the laser 10. The reflector mirror 12 is disposed in the cavity of the reflector cup 11. The pulsed laser beam is reflected by the reflector mirror 12 to become sheet structure light, and then reflected by the inner surface of the reflector cup 11 to form converging sheet structure light, ultimately forming an underwater illumination light layer.

[0062] In some other embodiments, both the first housing 15 and the imaging chamber 2 are watertight housings. These watertight housings are made of materials including, but not limited to, aluminum alloy, titanium alloy, or polytetrafluoroethylene (PTFE), preferably with good heat dissipation performance. Before use, the surface of the watertight housing undergoes anti-corrosion treatment.

[0063] According to embodiments of this disclosure, the underwater microscopic observation instrument also includes a power supply compartment 3, which supplies power to the light source compartment 1 and the imaging compartment 2. Accordingly, the outer shell of the power supply compartment 3 is also a watertight shell.

[0064] In one exemplary embodiment, an optical window is provided at the end of the light source chamber 1 away from the laser 10, including but not limited to being made of optical glass, fused silica or sapphire, to allow the sub-beam to pass through and reduce energy loss.

[0065] In one exemplary embodiment, the optical component further includes a beam expander 14, arranged along the optical axis between the laser 10 and the dimming component, which is adapted to change the diameter of the pulsed laser beam to adjust the thickness of the illumination layer.

[0066] In this implementation, the diameter of the pulsed laser beam output by the laser 10 changes after passing through the beam expander 14. The smaller the diameter of the pulsed laser beam, the thinner the final illumination layer.

[0067] According to embodiments of this disclosure, the ratio of the changed diameter of the pulsed laser beam to the original diameter is the beam magnification of the beam expander 14. The driving mechanism further includes a third driving component 300, which can drive the beam expander 14 to change the distance between the input lens and the output lens, thereby changing the beam magnification.

[0068] In one exemplary embodiment, the driving mechanism further includes a fourth driving component 400 adapted to drive the dimming component to move along the optical axis direction to adjust the position of the illumination layer.

[0069] Specifically, during operation, the adjustment range of the position of the illumination layer by the fourth drive component 400 is greater than that of the adjustment range of the position of the illumination layer by the first drive component 100, and the fourth drive component 400 should be controlled to make the adjustment first.

[0070] In one exemplary embodiment, the inner surface of the reflector cup 11 is a quadratic surface, so that the first driving component 100 adjusts the incident angle of the convergence of the second reflected beam while driving the reflector 12 to move.

[0071] In this implementation, when the position of the reflector 12 in the optical axis direction changes, the position of the first reflected beam reflected by the reflector 12 that illuminates the reflector cup 11 also changes. Since the inner surface of the reflector cup 11 is a quadratic surface, the reflection angle generated by the first reflected beam illuminating the reflector cup 11 will change, thereby changing the incident angle of the second reflected beam.

[0072] In one exemplary embodiment, the laser 10 is a white light pulse collimated laser with three primary colors combined, specifically a white light pulse collimated laser with red, green, and blue primary colors combined. The color of the output beam is changed by adjusting the power of the three primary colors to adapt to the underwater environment of different waters.

[0073] In one exemplary embodiment, the focusing mount 5 includes a plurality of connecting screws 51 and a focusing ring 52, one end of which is connected to the first housing 15. The focusing ring 52 is rotatably mounted at the end of the surface light source chamber 1 of the imaging chamber 2, and the other end of the connecting screws 51 is threadedly connected to the focusing ring 52.

[0074] In this embodiment, the connecting screw 51 is fixedly connected to the light source chamber 1, and the other end is threadedly connected to the focusing ring 52. The focusing ring 52 is rotatably sleeved on the imaging chamber 2 and is restricted to move along the optical axis. When the focusing ring 52 rotates, the thread on the connecting screw 51 engages with the focusing ring 52, so that the connecting screw 51 moves along the optical axis while rotating, thereby causing the light source chamber 1 to move closer to or away from the imaging chamber 2.

[0075] In one exemplary embodiment, at least one of the connecting screws 51 is a hollow screw, through which a cable suitable for electrically connecting the light source chamber 1 and the imaging chamber 2 can pass.

[0076] In one exemplary embodiment, the underwater microscopic observation instrument further includes a liquid-filled chamber 4, which is installed at one end of the imaging chamber 2 near the light source chamber 1. The scattering rate of the liquid inside the liquid-filled chamber 4 is lower than that of the external medium.

[0077] In this implementation, by setting up a liquid-filled chamber 4, the light beam passing through the observed target is maximized to propagate within the liquid-filled chamber 4, thereby reducing the impact of light pollution caused by scattering in the water on imaging.

[0078] For example, the liquid inside the liquid-filled chamber 4 can be deionized water, purified water, or a low-scattering colored transparent liquid; the liquid-filled chamber 4 can be constructed as an opaque chamber, which helps to reduce the impact of light pollution, or it can be constructed of optical glass to reduce the loss of light beams when passing through.

[0079] In some other embodiments, the imaging chamber 2 has a front end near the light source chamber 1 and a rear end. An optical window is provided at the front end to allow the light beam emitted from the liquid filling chamber 4 to pass through and enter the imaging chamber 2. This optical window is made of, but is not limited to, optical glass, fused silica, or sapphire.

[0080] According to an embodiment of this disclosure, the rear end of the imaging chamber 2 is connected to the power supply chamber 3 via a watertight connector, which is suitable for transmitting electrical energy or data.

[0081] In one exemplary embodiment, the imaging unit includes a telecentric lens 21 and an imaging camera 22. The telecentric lens 21 is adapted to receive and focus a light beam passing through the observed target for imaging by the imaging camera 22.

[0082] In this implementation, the telecentric lens 21 has a large depth of field and field of view, which is beneficial for the imaging camera 22 to produce clearer images.

[0083] In some other embodiments, the magnification of the telecentric lens 21 is variable, and the imaging camera 22 includes, but is not limited to, a high-definition microscope or a high-definition industrial camera, preferably with high resolution.

[0084] In one exemplary embodiment, the imaging chamber 2 further includes a control storage unit 23 configured to control the synchronous operation of the light source chamber 1 and the imaging chamber 2, and to store the generated images of the observed target.

[0085] According to an embodiment of this disclosure, a light source control base is also installed on the outer wall of the imaging chamber 2, and the cable in the light source control base is passed through the connecting screw 51 to electrically connect the light source chamber 1 and the control storage unit 23.

[0086] Figure 4 This is a schematic diagram of the illumination layer generated by the light source chamber in one embodiment provided in this disclosure.

[0087] Figure 4 The diagram shows three illumination layers when the diameter of the second reflected beam is 2 mm. The reference order is from left to right, with incident angles α of 45°, 30°, and 15°, and layer thicknesses H of 1.4 mm, 1.15 mm, and 1.05 mm, respectively.

[0088] Figure 5 This is a schematic diagram of the illumination layer generated by the light source chamber in another embodiment provided in this disclosure.

[0089] Figure 5 The diagram shows three illumination layers when the diameter of the second reflected beam is 6 mm. The reference order is from left to right, with incident angles α of 45°, 30°, and 15°, and layer thicknesses H of 4.15 mm, 3.6 mm, and 3.3 mm, respectively.

[0090] Figure 6 These are physical images comparing the imaging effects of the underwater microscopic observation instrument provided in this disclosure. The left image shows the imaging effect of conventional equipment, while the right image shows the imaging effect of the underwater microscopic observation instrument provided in this disclosure. It can be seen that the underwater microscopic observation instrument according to the above embodiments of this disclosure can achieve clearer imaging of the observed target, thus making it suitable for observing marine plankton such as phytoplankton, zooplankton, and bacteria. It enables rapid and accurate acquisition of information such as taxonomic composition, abundance, and particle size distribution of marine plankton, facilitating scientific research, emergency monitoring, and assessment of marine ecology.

[0091] Those skilled in the art will understand that the features described in the various embodiments and / or claims of this disclosure can be combined or combined in various ways, even if such combinations or combinations are not explicitly described in this disclosure. In particular, the features described in the various embodiments and / or claims of this disclosure can be combined or combined in various ways without departing from the spirit and teachings of this disclosure. All such combinations and / or combinations fall within the scope of this disclosure.

[0092] The embodiments of this disclosure have been described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of this disclosure. Although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination. The scope of this disclosure is defined by the appended claims and their equivalents. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of this disclosure, and all such substitutions and modifications should fall within the scope of this disclosure.

Claims

1. An underwater microscopic observation instrument, characterized in that, include: Imaging chamber (2), the imaging chamber (2) is equipped with an imaging unit, which is suitable for imaging underwater observation targets; as well as A light source chamber (1) is coaxially connected to the imaging chamber (2) via a focusing mount (5). The observation target is located between the light source chamber (1) and the imaging chamber (2), and includes: First shell (15); An optical assembly, mounted within the first housing (15), includes: Laser (10), suitable for outputting pulsed laser beams; and A dimming assembly includes a reflector (11), a conical mirror (12), and a lens (13) arranged sequentially along the optical axis of the pulsed laser beam; the reflector (12) is configured to reflect the pulsed laser beam using its conical reflective surface to form a first reflected beam; the first reflected beam is reflected by the inner surface of the reflector (11) to form a conical second reflected beam, and the second reflected beam passes through the lens (13) and converges on the optical axis to form an illumination layer; and A drive mechanism, installed within the first housing (15), includes: A first driving component (100) is configured to drive the reflector (12) to move along the optical axis to adjust the position of the illumination layer to be near the observation target; and The second drive assembly (200) is configured to drive the lens (13) to move along the optical axis to change the incident angle at which the second reflected beam converges, such that the thickness of the illumination layer is less than or equal to the depth of field of the imaging unit, thereby improving the clarity of the underwater imaging of the observed target by the imaging chamber (2).

2. The underwater microscopic observation instrument according to claim 1, characterized in that, The optical components also include: A beam expander (14) is arranged between the laser (10) and the dimming assembly along the optical axis and is suitable for changing the diameter of the pulsed laser beam to adjust the thickness of the illumination layer.

3. The underwater microscopic observation instrument according to claim 2, characterized in that, The drive mechanism also includes a third drive component (300). The beam expander (14) includes an input lens and an output lens, and the third drive assembly (300) is configured to change the distance between the input lens and the output lens to adjust the magnification of the beam expander (14).

4. The underwater microscopic observation instrument according to claim 1, characterized in that, The driving mechanism further includes a fourth driving component (400) adapted to drive the dimming component to move along the optical axis direction to adjust the position of the illumination layer.

5. The underwater microscopic observation instrument according to any one of claims 1-4, characterized in that, The inner surface of the reflector cup (11) is a quadratic surface, so that the first driving component (100) adjusts the incident angle of the convergence of the second reflected beam during the process of driving the reflector (12) to move.

6. The underwater microscopic observation instrument according to any one of claims 1-4, characterized in that, The laser (10) is a three-primary-color beam-combining white light pulse collimated laser and is configured such that the power of the three primary colors is adjustable to change the color of the output beam.

7. The underwater microscopic observation instrument according to any one of claims 1-4, characterized in that, The focusing mount (5) includes: Multiple connecting screws (51), one end of which is connected to the first housing (15); and A focusing ring (52) is rotatably mounted on the end of the imaging chamber (2) facing the light source chamber (1), and the other end of the connecting screw (51) is threadedly connected to the focusing ring (52).

8. The underwater microscopic observation instrument according to claim 7, characterized in that, Cables suitable for electrically connecting the light source chamber (1) and the imaging chamber (2) pass through at least one of the connecting screws (51).

9. The underwater microscopic observation instrument according to any one of claims 1-4, characterized in that, It also includes a liquid filling chamber (4), which is installed at one end of the imaging chamber (2) near the light source chamber (1), and the scattering rate of the liquid inside the liquid filling chamber (4) is lower than that of the external medium.

10. The underwater microscopic observation instrument according to any one of claims 1-4, characterized in that, The imaging unit includes a telecentric lens (21) and an imaging camera (22). The telecentric lens (21) is adapted to receive and focus a light beam passing through the observed target for imaging by the imaging camera (22).

11. The underwater microscopic observation instrument according to any one of claims 1-4, characterized in that, The imaging chamber (2) also includes a control storage unit (23) configured to control the synchronous operation of the light source chamber (1) and the imaging chamber (2) and to store the generated images of the observed target.

Images