Modular light field microscope system based on lytro light field camera and method of commissioning thereof

Abstract

The application discloses a modular light field microscope system based on a Lytro light field camera and a debugging method thereof, and belongs to the field of optical imaging and microscopy. The system comprises, in sequence along an optical path, a microscope objective, a first lens, a second lens and a Lytro light field camera, the focal length of the first lens is smaller than that of the second lens, and the two constitute a relay optical path; the system further comprises a modular mechanical support assembly composed of a cage rod and a cage plate, and each optical component can be axially slidably adjusted along the cage rod. The application further discloses a step-by-step debugging method for the system. The application takes advantage of the small volume and low cost of the commercial Lytro light field camera, breaks through the technical bottleneck that the Lytro camera cannot be used for microscopic observation through the focal length gradient double-lens relay optical path design, and has the advantages of compact system structure, portability, easy debugging, high-quality four-dimensional light field imaging of microscopic samples, and suitability for fluid particle three-dimensional speed measurement, biological fluorescence microscopy, in-situ microscale detection and other scenes.

Description

Technical Field

[0001] This invention relates to the field of optical imaging and microscopy, specifically to a modular light field microscope system based on a Lytro light field camera and its debugging method. It is suitable for the acquisition of four-dimensional light field information of microscopic samples, and is especially suitable for applications requiring portable and low-cost three-dimensional imaging, such as three-dimensional velocimetry of fluid particles, thin-layer biological fluorescence microscopy, and in-situ microscale detection. Background Technology

[0002] Light field microscopy is a novel computational imaging technique capable of simultaneously recording the spatial position and propagation direction of light rays from a sample. By coupling a microlens array into the optical path of a traditional microscope, this system can simultaneously acquire four-dimensional light field information of a sample during a single camera exposure. Combined with mathematical algorithms such as three-dimensional deconvolution and iterative reconstruction, the three-dimensional spatial distribution of the sample can be rapidly reconstructed. Compared to imaging techniques such as confocal microscopy and two-photon microscopy, which require point-by-point or layer-by-layer mechanical scanning, light field microscopy offers significant advantages such as snapshot-like three-dimensional imaging, high frame rate, and strong dynamic tracking capabilities. It has been widely applied in scenarios requiring high-precision dynamic process capture, such as live biological observation, particle field measurement, and fluid visualization.

[0003] Currently, light field microscopy is mainly achieved through two technical approaches: One approach is a customized integrated system solution. These systems typically consist of a microscope body, a microlens array, a high-speed camera, and related optical modules deeply coupled together, with highly customized optical design and mechanical structure. While the imaging performance is relatively stable, these systems are bulky and heavy, making on-site deployment and field testing difficult. The core optical components and imaging parts are highly specialized, resulting in high R&D and manufacturing costs, making them difficult to promote and apply in resource-constrained scenarios. Furthermore, the fixed optical path structure has poor scalability, making it difficult to flexibly adjust or upgrade functions according to specific application needs, thus limiting their application in diverse scenarios such as portable testing, in-situ imaging, and field experiments.

[0004] Another approach is to utilize commercial light field cameras for secondary development. Commercial consumer-grade light field cameras, exemplified by Lytro, incorporate high-precision calibrated microlens arrays and integrated optical paths, featuring compact structure, small size, low cost, and high integration. They also possess mature computational imaging capabilities such as "image first, focus later" and multi-view decoding. However, these cameras were initially designed for macroscopic scene photography, employing a closed, integrated structure. The native microlens array and imaging lens cannot be freely disassembled or replaced, and their native magnification is only sufficient for reducing the size of objects, not for directly magnifying and observing microscopic samples. Therefore, despite Lytro's strong hardware foundation and algorithmic ecosystem, its closed structure and macroscopic imaging limitations currently make it difficult to directly apply to the field of microscopic imaging.

[0005] In summary, existing light field microscopy technology mainly faces the following contradictions: On the one hand, although traditional customized light field microscopes can meet the needs of microscopic imaging, they are bulky, expensive, and have a fixed structure, making it difficult to meet the needs of emerging application scenarios such as portable deployment, rapid assembly, and on-site testing. On the other hand, although commercial light field cameras, represented by Lytro, have advantages such as compact structure, low cost and mature imaging ecosystem, their closed design and macroscopic imaging positioning make them unsuitable for direct observation of microscopic samples, and their potential application value has not been fully explored.

[0006] Therefore, how to leverage the advantages of commercial Lytro light field cameras—small size, low cost, and high integration—to overcome the technical bottleneck of their inability to be directly used for microscopic observation, and design a compact, easy-to-deploy, easy-to-debug light field microscope system capable of acquiring four-dimensional light fields from microscopic samples, has become an urgent technical problem to be solved. Summary of the Invention

[0007] This invention aims to solve the following technical problems existing in the current light field microscopy technology: traditional customized light field microscopes are bulky, expensive and have a fixed structure, making it difficult to meet the needs of portable deployment and on-site testing; while commercial Lytro light field cameras have the advantages of compact structure and low cost, their closed integrated design means that they can only be used for macroscopic scene shooting and cannot directly realize the magnified observation of microscopic samples.

[0008] Therefore, this invention provides a modular light field microscope system based on a Lytro light field camera and its debugging method. It aims to take advantage of the small size, low cost and high integration of commercial Lytro light field cameras, and through modular optical coupling design, overcome the technical bottleneck that prevents them from being used for microscopic observation, and realize a light field microscope system that is compact, portable, easy to debug, cost-controllable and capable of acquiring high-quality four-dimensional light field information of microscopic samples.

[0009] To achieve the above-mentioned objectives, the present invention provides the following technical solution: A modular light field microscope system based on a Lytro light field camera includes a microscope objective, a first lens, a second lens, and a Lytro light field camera arranged sequentially along the optical path. The first lens and the second lens form a relay optical path for coupling light emitted from the microscope objective to the photosensitive surface of the Lytro light field camera; the focal length of the first lens is shorter than that of the second lens.

[0010] As a preferred technical solution, the first lens has a focal length of 50mm and a maximum aperture of F1.2; the second lens has a focal length of 85mm and a maximum aperture of F1.4.

[0011] As a further preferred technical solution, the system further includes a mechanical support assembly, which comprises multiple cage plates and at least three cage rods. Each cage plate is used to fix the microscope objective, the first lens, the second lens, and the Lytro light field camera, and the centers of each cage plate are located on the same optical axis. The cage rods are arranged parallel to the optical axis, and each cage plate is movably connected to the cage rod and can slide along the axial direction of the cage rod to adjust the axial spacing between adjacent optical components. Preferably, each cage plate is provided with a locking member for fixing the cage plate relative to the cage rod after the cage plate slides to a preset position.

[0012] As a preferred technical solution, both the first lens and the second lens are commercially available interchangeable lenses, and their imaging modes can be adjusted to infinity imaging mode, and their apertures can be adjusted to the maximum aperture.

[0013] A debugging method for a modular light field microscope system based on a Lytro light field camera, applied to the aforementioned system, includes the following steps: Step 1: Fix the sample to be tested at the working distance in front of the microscope objective; Step 2: Set the first lens behind the microscope objective, and set the imaging mode of the first lens to infinity imaging and the aperture to the maximum. Step 3: Set the second lens behind the first lens, and set the imaging mode of the second lens to infinity imaging and the aperture to the maximum. Step 4: Place the Lytro light field camera behind the second lens, and make the photosensitive surface of the Lytro light field camera fit against the light-emitting surface of the second lens; Step 5: Adjust the distance between the first lens and the microscope objective along the optical axis so that the front end of the first lens is in contact with the rear end of the microscope objective. Step 6: Adjust the distance between the second lens and the first lens along the optical axis until the Lytro light field camera can clearly capture the image of the sample under test; Step 7: Fix the relative positions of each optical component.

[0014] As a preferred technical solution, in step six, when adjusting the distance between the second lens and the first lens, the image captured by the Lytro light field camera is observed in real time, and the standard for completion of the adjustment is that the image is clear.

[0015] As a preferred technical solution, in steps five and six, the spacing between optical components is adjusted by adjusting the cage plate corresponding to each optical component to slide along the axial direction of the cage rod.

[0016] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects: 1. This invention expands the application of the Lytro commercial light field camera in the field of microscopic imaging: For the first time, this invention proposes coupling a commercial Lytro light field camera with a microscope objective via a relay optical path, overcoming the technical bottleneck that limits the Lytro light field camera to macroscopic imaging due to its enclosed, integrated design. By using lenses 1 and 2 with gradient focal lengths to form a relay optical path, the intermediate image initially magnified by the microscope objective is precisely coupled to the photosensitive surface of the Lytro light field camera, enabling the commercial light field camera, which originally only had the ability to reduce image size, to achieve magnified observation of microscopic samples. Experimental verification shows that when using the system of this invention to acquire scale light field images, the actual magnification can reach 1.5 times, significantly expanding the application range of the Lytro light field camera.

[0017] 2. Compact structure, low cost, easy portability and field deployment: This invention adopts a modular design concept, integrating the microscope objective, two commercial lenses, and the Lytro light field camera onto the same optical axis through a cage system (cage rods and cage plates). Each optical component is detachable and reassembled, resulting in a compact, small, and lightweight design that facilitates portability and rapid field deployment. Furthermore, the core components of the system utilize the commercially available Lytro light field camera and lenses, eliminating the need for customized, expensive optical modules. This significantly reduces the research and development and manufacturing costs of light field microscopes, promoting the widespread adoption of the technology.

[0018] 3. Simple optical path debugging and stable and reliable imaging quality: This invention features a dedicated step-by-step debugging method for the aforementioned modular structure. This method is simple to operate and requires no complex professional calibration equipment. Position calibration of each optical component and optical path optimization can be completed through simple sliding adjustments and real-time observation. During debugging, both lenses are set to infinity imaging mode and opened to their maximum aperture to maximize light transmission and reduce optical path loss. Seamless docking of lens 1 with the microscope objective and sliding lens 2 until the image is clear ensures precise optical path coupling. After debugging, the positions of each component are fixed by tightening screws, ensuring the mechanical stability and long-term imaging reliability of the system.

[0019] 4. Strong system scalability and wide applicability: The modular design of this invention allows for flexible replacement of optical components according to specific application requirements: the microscope objectives can be replaced according to the magnification requirements of the observed samples; lenses 1 and 2 can be selected from commercial lenses with different focal lengths, as long as the focal length of the pre-stage lens is less than that of the post-stage lens; the Lytro light field camera can also be other models of commercial light field cameras. This high scalability enables this invention to adapt to the needs of various application scenarios such as three-dimensional velocimetry of fluid particles, thin-layer biological fluorescence microscopy, and in-situ microscale detection, and has good engineering practical value. Attached Figure Description

[0020] The present invention and its accompanying drawings are used to further explain the technical solutions of the present invention, constitute a part of the specification, and, together with the specific embodiments, are used to enable those skilled in the art to fully understand and implement the present invention. In the drawings: Figure 1 A schematic diagram of the structure of a modular light field microscope system based on a Lytro light field camera provided in an embodiment of the present invention; Figure 2 The scale light field image is acquired by the modular light field microscope system based on the Lytro light field camera provided in Embodiment 1 of the present invention. Figure 3 The image shows a thread light field acquired by the modular light field microscope system based on the Lytro light field camera provided in Embodiment 2 of the present invention. Figure 4 for Figure 3 The image is composed of the central viewpoint image extracted from the central pixels under each microlens array.

[0021] Explanation of the markings on the components in the attached diagram: 1-Microscopic objective; 2-First lens; 3-Second lens; 4-Lytro light field camera; 5-Cage rod; 6-Cage plate; 7-Locking screw. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the specific embodiments described herein are only for explaining the invention and are not intended to limit the scope of protection of the invention. After reading this specification, those skilled in the art can make various equivalent substitutions, modifications, or combinations to the technical solutions described in this invention without departing from the concept of the invention, and these all fall within the scope of the technical concept of this invention.

[0023] like Figure 1As shown, the present invention provides a modular light field microscope system based on a Lytro light field camera, mainly comprising two parts: an optical imaging component and a mechanical support component. The optical imaging component is arranged sequentially along the optical path: a microscope objective 1, a first lens 2, a second lens 3, and a Lytro light field camera 4. The mechanical support component includes four cage rods 5 and multiple cage plates 6. Each cage plate 6 is used to fix the aforementioned optical components and is adjustablely fixed to the cage rods 5 by locking screws 7.

[0024] This modular coaxial optical structure design ensures that the optical axes of each optical component are strictly aligned, guaranteeing unbiased light propagation and laying the physical foundation for subsequent high-quality light field information acquisition. Compared with traditional customized light field microscopes, the modular design of this invention allows for rapid disassembly and assembly, and flexible reconfiguration, greatly improving the system's portability and environmental adaptability.

[0025] The optical imaging components include: (a) Microscope Objective: Microscope objective 1 serves as the primary imaging component of the system, used for preliminary magnification and imaging of the microscopic sample under test in the object space. In a preferred embodiment of the present invention, microscope objective 1 is a commercially available microscope objective with a magnification of 10x and a numerical aperture (NA) of 0.25. This numerical aperture selection balances the requirements of resolution and depth of field, ensuring sufficient sample detail while maintaining a certain depth of focus range, facilitating subsequent optical path coupling and adjustment.

[0026] It should be noted that the specific parameters of microscope objective 1 are not fixed. In practical applications, microscope objectives with different magnifications and numerical apertures can be flexibly changed according to the scale characteristics of the sample being measured and the observation requirements. For example, for observing biological samples at the cellular level, a 40x objective with NA 0.65 can be selected to obtain a preliminary image with higher resolution; for applications requiring a larger field of view, such as particle field measurements, a 4x objective with NA 0.1 can be selected to expand the observation range. This interchangeability is one of the important advantages of the modular design of this invention.

[0027] (ii) Relay optical path: The first lens 2 and the second lens 3 together constitute the relay coupling optical path. Its core function is to accurately couple the intermediate image light emitted from the microscope objective 1 to the photosensitive surface of the Lytro light field camera 4, and in the process, improve the overall magnification of the system.

[0028] In a preferred embodiment of the present invention, the first lens 2 is a Nikon commercial lens with a focal length of 50mm and a maximum aperture of F1.2; the second lens 3 is a Nikon commercial lens with a focal length of 85mm and a maximum aperture of F1.4. This specific selection is based on the following considerations: Firstly, the design of the focal length gradient (the focal length of the first lens 2, 50mm, is less than the focal length of the second lens 3, 85mm) is key to achieving an overall increase in system magnification. According to optical imaging principles, when the relay light path consists of two lenses and the focal length of the front lens is less than that of the rear lens, the system as a whole will exhibit a magnification effect. Experimental verification of this invention shows that, with this focal length combination, the overall system magnification can reach 1.5 times, breaking through the limitation of the Lytro light field camera 4, which natively can only reduce image size.

[0029] Secondly, the large aperture design (F1.2 and F1.4) ensures maximum light transmission in the optical path. In microscopic imaging scenarios, samples are often low in brightness, especially fluorescent samples, whose emitted light intensity is even weaker. Using a large aperture lens can effectively reduce light loss in the optical path, ensuring that the final image has sufficient signal-to-noise ratio and brightness. This design consideration is particularly important for low-light scenarios such as fluorescence microscopy.

[0030] Third, the selection of Nikon commercial lenses is not based on technological exclusivity, but rather on their mature manufacturing process, stable optical performance, and widespread market availability. Those skilled in the art should understand that the core of this invention lies in achieving relay coupling and magnification functions through a dual-lens combination with a specific focal length relationship, rather than dependence on a specific brand. Therefore, any commercial or custom lens that meets the focal length relationship and has sufficient light transmission capability can be used as an alternative.

[0031] During the debugging process, both lens 2 and lens 3 need to be set to infinity imaging mode. This is because in infinity imaging mode, the incident light rays exit as parallel light after passing through the lens. This optical path characteristic means that adjusting the distance between the two lenses will not affect the image sharpness, but only the length of the optical path and the coupling efficiency, thus providing great convenience for the debugging work.

[0032] (III) Lytro Light Field Camera: The Lytro Light Field Camera 4 serves as the core light field information acquisition component of the system. It features a built-in high-precision calibrated microlens array and an integrated optical path, enabling it to directly acquire four-dimensional light field information (including the spatial position and propagation direction of light) of microscopic samples transmitted through the preceding optical path. This camera possesses mature computational imaging capabilities such as "image first, focus later" and multi-view decoding, eliminating the need for an additional light field acquisition module and effectively simplifying the system structure.

[0033] A key innovation of this invention lies in the fact that, for the first time, the Lytro light field camera 4, originally used only for macroscopic scene photography, has been introduced into the field of microscopic imaging through external optical design. The significance of this breakthrough is that it leverages the advantages of the Lytro light field camera 4—its small size, low cost, and mature algorithm ecosystem—while avoiding the high costs and technical barriers associated with traditional light field microscopes that require customized microlens arrays and complex optical paths.

[0034] It should be noted that although this embodiment uses a commercial light field camera from the Lytro brand as an example, the technical concept of the present invention is not limited to this specific brand. Any commercial or custom light field camera that uses microlens array technology to achieve light field acquisition, as long as it has a compact, integrated structure, can serve as the core acquisition component of the present invention. This retention of alternative solutions makes the scope of protection of the present invention more expansive.

[0035] like Figure 1 As shown, the mechanical support assembly consists of cage rods 5, cage plates 6, and locking screws 7.

[0036] The cage rods 5 are high-strength, rigid rods, preferably four in number, arranged in a rectangle and passing through the four corners of all cage plates 6. The symmetrical distribution of the four cage rods 5 ensures the stability and uniform stress distribution of the entire mechanical structure, effectively preventing optical axis misalignment caused by unilateral stress. The cage rods 5 can be made of high-strength, lightweight materials such as stainless steel, aluminum alloy, or carbon fiber to reduce the overall weight and improve portability while maintaining rigidity.

[0037] The cage plate 6 is a customized mounting plate adapted to the dimensions of various optical components. Each optical component (microscope objective 1, first lens 2, second lens 3, Lytro light field camera 4) corresponds to one cage plate 6. The components can be fixed to the center of the cage plate 6 by threaded connection, bayonet connection, or special clamps, ensuring that their optical axis is strictly coincident with the center of the cage plate 6. This "one component, one cage plate" design allows each optical component to be adjusted and replaced independently, greatly improving the maintainability and expandability of the system.

[0038] The cage plate 6 and the cage rod 5 are movably connected, allowing them to slide freely along the axial direction of the cage rod 5. This structural feature provides crucial adjustability for optical path optimization during system debugging. When it is necessary to adjust the axial distance between two optical components, simply loosen the corresponding locking screw 7, slide the cage plate 6 along the cage rod 5 to the target position, and then tighten the locking screw 7 to complete the fixation. This adjustment method is simple to operate, has controllable precision, and does not require a complex displacement platform or laser collimation equipment.

[0039] The design of the locking screw 7 ensures both reliable fixation and ease of operation. During the debugging process, the locking screw 7 can be in a semi-locked state, which allows the cage plate 6 to slide while preventing accidental slippage due to complete loosening. After debugging, the locking screw 7 can be fully tightened to ensure the mechanical stability of the entire system and prevent optical path deviation caused by vibration or movement during subsequent use.

[0040] The debugging method of this invention is a dedicated step-by-step debugging process designed for the aforementioned modular system structure. Its core lies in quickly completing the position calibration and optical path optimization of each optical component through simple sliding adjustments and real-time observation. The following is a detailed explanation of the specific operation steps.

[0041] Step 1: Sample Fixation. Fix the resolution target (such as the USAF 1951 resolution test target) at the working distance in front of microscope objective 1. The resolution target is the preferred sample during the calibration process because its regularly arranged line pairs facilitate quick assessment of image sharpness through visual inspection or image software. When fixing, ensure that the target plane is perpendicular to the optical axis of microscope objective 1 and is within the effective imaging range of the objective to avoid aberrations and uneven brightness caused by tilting or deviation.

[0042] Step 2: Lens 1 Installation and Parameter Settings. Slide the cage plate 6, which houses the first lens 2, to a specific distance behind the microscope objective 1 and temporarily fix it (locking screw 7 partially tightened). Set the imaging mode of the first lens 2 to infinity imaging and the aperture to its maximum (F1.2). Setting the infinity imaging mode ensures that the outgoing light from the first lens 2 is parallel, providing an ideal beam shape for subsequent coupling with the second lens 3; setting the maximum aperture maximizes light transmission and reduces optical path loss, making it particularly suitable for imaging low-light samples.

[0043] Step 3: Lens 2 Installation and Parameter Settings. Slide the cage plate 6, which houses the second lens 3, to a specific distance behind the first lens 2 and temporarily fix it in place. Set the imaging mode of the second lens 3 to infinity imaging and the aperture to its maximum (F1.4). Although the F1.4 of the second lens 3 is slightly smaller than the maximum aperture (F1.2) of the first lens 2, in the actual optical path, after collimation by the first lens 2, the light already has good parallelism, and the light transmission at F1.4 is sufficient to meet the imaging requirements.

[0044] Step 4: Lytro Light Field Camera Installation and Parameter Settings. Mount the Lytro light field camera 4 flush against the rear surface of the second lens 3, ensuring the camera's photosensitive surface and the light-emitting surface of the second lens 3 are fully aligned without gaps or misalignment. This flush design is to avoid stray light and reflection loss that may occur in air gaps, ensuring light enters the camera with maximum efficiency. Simultaneously, set the Lytro light field camera 4 to its maximum magnification setting to provide a basic magnification for imaging microscopic samples. It should be noted that the Lytro camera's "magnification setting" differs from traditional camera zoom; it is essentially a scaling factor used for digital processing of the acquired light field data. Maximizing it helps to obtain richer detail information later.

[0045] Step 5: Fine-tuning the position of lens 1. Keeping the imaging mode and aperture parameters of the first lens 2 unchanged, slowly slide the cage plate 6, which houses the first lens 2, towards the microscope objective 1 along the axis of the cage rod 5 until the front surface of the first lens 2 is flush against the rear surface of the microscope objective 1, completing the seamless connection between lens 1 and the microscope objective. This "flush" design aims to shorten the distance from the primary image to the first lens in the relay optical path, reduce light divergence loss during propagation in the air, and optimize the coupling efficiency of the primary imaging optical path.

[0046] Step 6: Fine-tuning the position of lens 2 and fixing the system. Keeping the aperture parameters of the second lens 3 and the mounting position and parameters of the Lytro light field camera 4 unchanged, slowly slide the cage plate 6, which mounts the second lens 3, towards the first lens 2 along the axis of the cage rod 5. During the sliding process, observe the image captured by the Lytro light field camera 4 in real time (this can be previewed via the camera's built-in display or by connecting to a computer) until the camera can clearly capture the detailed features of the target (such as the smallest resolvable line pairs). At this point, the optimization and calibration of the entire optical path is complete. Then, tighten all the locking screws 7 between the cage plate 6 and the cage rod 5 to completely fix the position of each optical component, ensuring the mechanical and optical stability of the entire system.

[0047] The core advantage of this debugging method lies in the fact that the entire debugging process only requires a resolution target and real-time observation equipment, eliminating the need for expensive laser collimators, autocollimators, or precision displacement platforms, thus greatly reducing the deployment threshold and debugging difficulty of the system. Furthermore, the key operational nodes during the debugging process (such as lens 1 being pressed firmly against the microscope objective, and lens 2 sliding until the image is clear) are all well-defined and repeatable operational standards, ensuring the consistency and stability of the debugging results.

[0048] The following combination Figure 1 The system structure shown describes the working process of this invention in detail: The light emitted (natural light or fluorescence) from the microscopic sample being measured (such as fluid particles, biofluorescent samples, or resolution targets) located in the object space first enters the microscope objective 1. The microscope objective 1 performs preliminary magnification imaging of the sample, forming an intermediate real image of the sample behind the objective.

[0049] The light emitted from the intermediate real image continues to be incident on the first lens 2 along the coaxial optical path. Since the first lens 2 is set to infinity imaging mode, it acts as a collimating lens, converting the diverging light rays from the microscope objective 1 into a parallel beam output. This collimation process keeps the light beam in a constricted state during subsequent transmission, reducing energy divergence.

[0050] Parallel light rays pass through the first lens 2 and then into the second lens 3. The second lens 3 is also in infinity imaging mode, and its function is to refocus the incident parallel light beam onto the photosensitive surface of the Lytro light field camera 4 behind it. Since the focal length of the second lens 3 (85mm) is greater than that of the first lens 2 (50mm), according to the principle of optical magnification, this relay optical path exhibits a magnification effect, making the final image size larger than the intermediate image size formed by the microscope objective 1.

[0051] Finally, the Lytro Light Field Camera 4's built-in microlens array modulates the incident light field, completing the acquisition and storage of four-dimensional light field information of the sample under test. The acquired raw light field data can be further processed through supporting computational imaging algorithms, such as digital refocusing, multi-view image synthesis, and three-dimensional deconvolution reconstruction, providing data support for applications such as three-dimensional velocimetry of fluid particles and dynamic tracking of biological samples.

[0052] To verify the effectiveness of the technical solution of this invention, the inventors conducted multiple sets of experiments. Two specific embodiments are provided below: Example 1: Ruler Imaging Experiment Using the above system and debugging method, an imaging experiment was conducted with a ruler as the test sample. Figure 2 This is a light field image of the scale acquired in this embodiment. From... Figure 2 As can be clearly seen, the scale features of the ruler are completely recorded, and the sub-images under each microlens are arranged adjacently without overlap or distortion, indicating that the system's optical path is properly adjusted and the imaging quality is good. Actual measurements show that the two black lines on the ruler, with an actual spacing of 1 mm, have an imaging spacing of 1.5 mm in the light field image, indicating that the actual magnification of this light field microscope system can reach 1.5 times. This magnification breaks through the native shooting magnification limit of commercial Lytro light field cameras, effectively expanding the shooting range of Lytro light field cameras and extending it from macroscopic light field imaging to the field of microscopic light field observation.

[0053] Example 2: Thread Defect Imaging Experiment Using the system and debugging method of this invention, an imaging experiment was conducted with a thread as the test sample. Figure 3 The original light field image (macro image) is blurry when directly observed because each microlens records multi-view information. However, by extracting pixels at the same location under each microlens array, a new image can be formed. For example, by extracting the center pixel under each microlens array, a central viewpoint image can be created. Figure 4 As shown. From Figure 4 As can be seen, the circled areas are defects in the thread, which cannot be observed with the naked eye or by the Lytro light field camera.

[0054] The above embodiments fully demonstrate the reliability and practicality of the system of the present invention, and can meet the needs of various application scenarios such as three-dimensional velocimetry of fluid particles, thin-layer biological fluorescence microscopy, and in-situ microscale detection.

[0055] In a preferred embodiment of the present invention, the first lens 2 and the second lens 3 are Nikon commercial lenses with focal lengths of 50mm and 85mm, respectively. However, those skilled in the art should understand that the core of the present invention lies in achieving relay coupling and magnification functions through a focal length gradient (the focal length of the preceding lens is less than that of the following lens), rather than limiting specific focal length values ​​or specific brands. Therefore, those skilled in the art will understand that the following alternatives can also be used to implement the present invention: 1. Alternative focal length combinations: Other focal length combinations can be selected based on the required overall system magnification and optical path length, such as 35mm and 50mm, 50mm and 100mm, 85mm and 135mm, etc. As long as the focal length of the first lens 2 is less than the focal length of the second lens 3, the magnification effect of this invention can be achieved.

[0056] 2. Lens type alternatives: In addition to commercially available interchangeable lenses, custom-designed lens assemblies can also be used. The advantages of custom lenses are that aberration optimization, size reduction, and cost reduction can be achieved according to specific application requirements, making them particularly suitable for mass production scenarios.

[0057] 3. Lens Aperture Alternatives: In applications with ample light (such as high-brightness fluorescent or reflected light samples), the aperture can be appropriately reduced to achieve greater depth of field or better aberration control. The choice of the maximum aperture is not absolutely necessary, but rather should be optimized based on actual lighting conditions.

[0058] In a preferred embodiment of the invention, the mechanical support assembly employs a cage structure with four cage rods and multiple cage plates. However, those skilled in the art will understand that the methods for achieving modular, adjustable mechanical support are not limited to this. Those skilled in the art will understand that the following alternatives can also be used to implement the invention: 1. Alternatives in the number of cage rods: Three cage rods arranged in a triangle can achieve the same stable support and guidance function, and may even be more advantageous in some compact designs. Four cage rods offer greater stability, but add some weight and cost; both have their advantages and disadvantages.

[0059] 2. Alternative to the guide rail structure: Linear guide rails and sliders can replace the cage rod and cage plate structure. Linear guide rails offer higher positioning accuracy and smoother sliding, making them suitable for applications requiring higher debugging precision.

[0060] 3. Alternative to threaded sleeve structure: Axial distance can be adjusted using internally and externally threaded sleeves. Fine spacing adjustments are achieved by rotating the sleeve, and fixation is achieved by the self-locking property of the threads. This structure is more common in some compact equipment.

[0061] In a preferred embodiment of the present invention, the core acquisition component uses a commercial light field camera from Lytro. However, those skilled in the art will understand that the technical concept of the present invention can be extended to any imaging device that uses microlens array technology to achieve light field acquisition. Those skilled in the art will also understand that the following alternatives can also be used to implement the present invention: 1. Alternatives to other commercial light field cameras: Besides Lytro, there are other brands or models of commercial light field cameras on the market, such as Raytrix. Although these cameras differ in specific parameters and interface standards, they can all be compatible with this invention by adapting the corresponding mechanical interfaces and optical path parameters.

[0062] 2. Alternatives to Custom Light Field Cameras: For specific application requirements, a combination of microlens arrays and image sensors can be designed and fabricated as the core acquisition component. The advantage of a custom solution is that it can be optimized according to the specific optical path parameters of the microscopic system, resulting in better matching and imaging performance.

[0063] 3. Replacement with detachable microlens arrays: For certain high-end scientific research applications, a combination of independent microlens array modules and high-performance industrial cameras can be used to replace integrated light field cameras. Although this approach increases structural complexity, it offers higher imaging sensitivity and more flexible configuration options.

[0064] Furthermore, the debugging method of the present invention can be adaptively adjusted according to specific application scenarios. Those skilled in the art will understand that the following extended solutions can also be used to implement the present invention: 1. Extension of automated debugging: In scenarios requiring batch debugging or high-precision repetitive debugging, an electric displacement stage and autofocus algorithm can be introduced to replace the manual sliding steps in this debugging method with automated control, thereby improving debugging efficiency and accuracy.

[0065] 2. Introduction of auxiliary calibration equipment: When conditions permit, a laser collimator or autocollimator can be introduced to assist in calibration, further improving the coaxial accuracy of each optical component and meeting the requirements of higher resolution imaging.

[0066] 3. Adjustment of debugging sequence: In specific application scenarios, the order of debugging steps can be adjusted according to the actual optical path conditions and sample characteristics. For example, when the light transmission in the optical path is insufficient, aperture adjustment of lens 1 and lens 2 can be performed first, followed by fine-tuning of the position.

[0067] The modular light field microscope system based on the Lytro light field camera and its debugging method proposed in this invention have broad application prospects. In the biomedical field, it can be applied to rapid three-dimensional imaging of thin-layer biological tissues, tracking of cell dynamic behavior, and in vivo fluorescence observation; in the field of fluid mechanics, it can be applied to three-dimensional velocimetry of particles in microfluidic chips, two-phase flow field measurement, and analysis of atomized droplet size distribution; in the field of materials science, it can be applied to the detection of internal defects in transparent materials and the measurement of surface morphology of micro- and nanostructures; in the field of field science and on-site testing, it can be applied to on-site imaging of biological samples in remote areas, particle detection of environmental water samples, and bedside diagnosis in mobile healthcare. The low cost, portability, and ease of deployment of this invention will strongly promote the transition of light field microscopy technology from the laboratory to practical applications, serving a wider range of scientific research and industrial needs.

Claims

1. A modular light field microscope system based on a Lytro light field camera, characterized in that, include: The microscope objective, the first lens, the second lens, and the Lytro light field camera are arranged sequentially along the optical path. The first lens and the second lens form a relay optical path, used to couple the light emitted from the microscope objective to the photosensitive surface of the Lytro light field camera; the first lens is used to collimate the diverging beam of the intermediate real image formed by the microscope objective into a parallel beam, and the second lens is used to converge the parallel beam to the photosensitive surface of the Lytro light field camera, so that the relay optical path as a whole presents a magnification effect, and the final image size is larger than the size of the intermediate image formed by the microscope objective; Both the first lens and the second lens are commercially available interchangeable lenses, and both are set to infinity imaging mode and maximum aperture. It also includes a mechanical support assembly, which comprises: Four cage plates are provided, each used to fix the microscope objective, the first lens, the second lens and the Lytro light field camera, and the center of each cage plate is located on the same optical axis; each optical component corresponds to one cage plate, and the component is fixed to the center position of the cage plate by threaded connection, bayonet connection or special clamp, and its optical axis is strictly coincident with the center of the cage plate; Four cage rods are arranged in a rectangle and pass through the four corners of all cage plates. The cage rods are arranged parallel to the optical axis. Each cage plate is movably connected to the cage rod and can slide along the axial direction of the cage rod to adjust the axial spacing between adjacent optical components. A locking element is used to fix the cage plate relative to the cage rod after the cage plate has slid to a preset position.

2. The modular light field microscope system based on the Lytro light field camera according to claim 1, characterized in that, The first lens has a focal length of 50mm and a maximum aperture of F1.2; the second lens has a focal length of 85mm and a maximum aperture of F1.

4.

3. A debugging method for a modular light field microscope system based on a Lytro light field camera, applied to the modular light field microscope system of claim 1, characterized in that, The debugging method includes the following steps: Step 1: Fix the sample to be tested at the working distance in front of the microscope objective; Step 2: Set the first lens behind the microscope objective, and set the imaging mode of the first lens to infinity imaging and the aperture to the maximum. Step 3: Set the second lens behind the first lens, and set the imaging mode of the second lens to infinity imaging and the aperture to the maximum. Step 4: Place the Lytro light field camera behind the second lens, and make the photosensitive surface of the Lytro light field camera fit against the light-emitting surface of the second lens; Step 5: Keeping the imaging mode and aperture parameters of the first lens unchanged, adjust the distance between the first lens and the microscope objective along the optical axis so that the front end of the first lens is in contact with the rear end of the microscope objective. Step 6: Keep the aperture parameters of the second lens and the installation position of the Lytro light field camera unchanged, adjust the distance between the second lens and the first lens along the optical axis, and observe the shooting screen of the Lytro light field camera in real time until the Lytro light field camera can clearly capture the image of the sample under test. The standard for completion of adjustment is clear imaging. Step 7: Fix the relative positions of each optical component.

4. The debugging method according to claim 3, characterized in that, In steps five and six, the spacing between optical components is adjusted by sliding the cage plate corresponding to each optical component along the axial direction of the cage rod.

5. The debugging method according to claim 3, characterized in that, In step one, the sample being tested is a resolution target.

6. The debugging method according to claim 3, characterized in that, In step four, the magnification of the Lytro light field camera is adjusted to the maximum setting of the device.

Images