Laser focusing device and focusing method thereof

Abstract

The invention relates to a laser focusing device and a focusing method thereof, and belongs to the technical field of medical equipment optics, the laser focusing device comprises a bottom plate, a base, a laser unit, a focusing unit and a driving unit, the laser unit and the focusing unit are installed on the base, the base is rotatably connected with the bottom plate, the laser unit generates laser, and the driving unit drives the focusing unit to rotate. The focusing unit focuses the laser, and the driving unit pushes the base to rotate so as to adjust the position of a laser beam focusing point. According to the invention, the laser focusing point can be adjusted, and the device is suitable for optical test scenes requiring high-precision focusing, such as a flow cytometer.

Description

Technical Field

[0001] The present invention relates to the field of optical technology of medical equipment, and in particular to a laser focusing device and a focusing method thereof. Background Art

[0002] In the field of optical testing, especially in precision instruments such as flow cytometers, the shaping and focusing of laser light sources is one of the key technical requirements. Generally, the laser needs to be shaped and focused at a specific position to form an optical path that meets the spot size requirements. When the focused spot is at the optimal position, its area is the smallest and the energy density is the highest, which can achieve the best effect. For example, in a flow cytometer, the laser spot needs to be focused to the micron level in order to accurately test cell-sized objects. However, when the spot is offset, the feedback signal will be significantly weakened, resulting in a decrease in the instrument's detection accuracy. Therefore, extremely high requirements are placed on the adjustment stability of the incident light and the reliability of the fixation after the adjustment is completed.

[0003] At present, plane mirror structures are commonly used in flow cytometers to adjust the light path. Specifically, Figure 1 As shown, the laser is reflected to the focusing lens holder 3 by the coated reflector 2, so that the light spot is focused and aligned with the test cell. This optical path adjustment method requires adjusting multiple parameters at the same time, including the pitch angle, horizontal angle, position of the reflector and the position of the focusing lens. However, this method has the following disadvantages: first, there are many adjustment dimensions, the operation is cumbersome, and the adjustment process is complicated and time-consuming; second, the optical path is long and the structure is complex, resulting in a high overall system cost; in addition, since the adjustment process relies on manual operation, it is difficult to achieve automated adjustment, which limits its application in efficient and automated testing scenarios. Therefore, the existing technology has a lot of room for improvement in terms of the simplicity of optical path adjustment, compact structure, cost control and automated implementation, and a new technical solution is urgently needed to solve the above problems. Summary of the Invention

[0004] The purpose of this invention is to overcome the defects in the prior art and provide a laser focusing device and focusing method thereof, so as to partially or completely solve the technical problems of the existing laser focusing technology, such as multiple adjustment dimensions, cumbersome operation, complex and time-consuming adjustment process, long optical path, complex structure, resulting in high overall system cost, reliance on manual operation during the adjustment process, difficulty in achieving automated adjustment, and thus limiting its application in efficient and automated testing scenarios. In order to achieve the above purpose, this invention provides the following technical solutions:

[0005] In a first aspect, a laser focusing device includes: a base plate, a pedestal, a laser unit, a focusing unit and a driving unit, wherein the laser unit and the focusing unit are mounted on the pedestal, the pedestal and the base plate are rotatably connected, the laser unit generates laser, the focusing unit focuses the laser, and the driving unit drives the pedestal to rotate to adjust the focus position of the laser beam.

[0006] Optionally, the rotation center of the base and the bottom plate is O, the focal point of the laser beam is F, and the laser focusing device includes a first focusing working position and a second focusing working position. When the laser focusing device works in the first focusing working position, the line OF connecting the rotation center and the focal point is parallel to the horizontal direction. When the laser focusing device works in the second focusing working position, the line OF connecting the rotation center and the focal point forms an angle θ with the horizontal direction, 0°

[0007] <θ≤10°.

[0008] Optionally, the laser unit includes a light source, a polarizer, a spectrometer, a filter, and a detector. The laser beam generated by the light source passes through the polarizer to form a linearly polarized beam. The spectrometer divides the linearly polarized beam into transmitted light and reflected light. The transmitted light passes through the filter to filter out stray light, and the detector monitors the intensity of the reflected light.

[0009] Optionally, the focusing unit includes an angle plate, an angle plate holder, a wave plate, a focusing lens, a lens base, a locking piece, a focusing lens barrel, and a locking ring. The angle plate is installed on the angle plate holder, the angle plate holder and the wave plate are installed on the lens base, the locking piece locks the focusing lens barrel, the focusing lens is installed on the focusing lens barrel, and the locking ring is installed on the focusing lens barrel.

[0010] Optionally, the laser focusing device also includes a connecting unit, which includes a connecting member, a fixed block, a first fixing member, a first spring, a second fixing member, and a second spring. The base is connected to the bottom plate through the connecting member, the fixed block is connected to the bottom plate, one end of the first spring is connected to one side of the first fixing member, the other end of the first spring is connected to one side of the second fixing member, the other side of the first fixing member is connected to the fixed block, the other side of the second fixing member is connected to the base, and the second spring presses the base.

[0011] Optionally, the driving unit includes a brake, a motor, a screw, a nut block, a movable plate, a push rod, a spring, and an encoder. The driving unit is installed on the base plate. The motor drives the screw to rotate, and the rotation of the screw drives the nut block to move. The encoder is connected to the screw. The encoder is connected to the base plate through the mounting plate. The spring is located between the movable plate and the mounting plate. The spring presses the movable plate so that the movable plate contacts the nut block. The push rod is installed on the movable plate, and the push rod drives the base to rotate.

[0012] Optionally, along the first direction, in the first focusing working position, the distance from the push rod to the rotation center O is L1, and the distance from the focusing point F to the rotation center O is L2; in the second focusing working position, along the second direction, the distance moved by the push rod is H2, and the distance moved by the focusing point is H1, satisfying: H1 / H2=L1 / L2.

[0013] In a second aspect, the present invention provides a method for operating a laser focusing device, using any one of the laser focusing devices described in the first aspect, comprising:

[0014] Step S100, when the laser focusing device is working in the first focusing working position, the line OF connecting the rotation center O of the base and the bottom plate and the focusing point F is parallel to the horizontal direction;

[0015] Step S200: The driving unit drives the base to rotate relative to the base plate to adjust the focus position of the laser beam to switch from the first focusing position to the second focusing position.

[0016] Step S300: When the laser focusing device is working in the second focusing position F2, the line OF connecting the rotation center and the focus point forms an angle θ with the horizontal direction, 0°<θ≤10°.

[0017] Optionally, along the first direction, in the first focusing working position, the distance from the push rod to the rotation center O is L1, and the distance from the focusing point F to the rotation center O is L2; in the second focusing working position, along the second direction, the distance moved by the push rod is H2, and the distance moved by the focusing point is H1, satisfying: H1 / H2=L1 / L2.

[0018] Optionally, step S200 includes: the motor drives the lead screw to rotate, and the rotational motion of the lead screw is converted into linear motion of the nut block. The spring is located between the movable plate and the mounting plate. The spring presses the movable plate to keep it in close contact with the nut block. The spring provides elastic force to eliminate the gap between the nut block and the movable plate. After the linear motion of the nut block, the spring drives the movable plate to move. The push rod is installed on the movable plate, and the push rod moves with the movable plate. The push rod transmits its displacement to the base, so that the base rotates about the rotation center of the base and the bottom plate.

[0019] In summary, the present invention has the following beneficial technical effects:

[0020] (1) In the present invention application, firstly, the driving unit can perform high-precision control on the rotation of the base, so that the adjustment of the laser beam focal point position can reach the precision of micron level, meeting the requirements of high-precision applications. Compared with the traditional optical path system that requires multi-dimensional adjustment, the device can adjust the focal point position through a single rotation of the base, which is simpler to operate and has fewer adjustment dimensions. In addition, the rotation connection design between the base and the bottom plate, combined with the precise control of the driving unit, ensures the stability of the system during the adjustment process and reduces the influence of vibration or external interference on the accuracy. The laser unit, focusing unit and driving unit are integrated on the base, making the device compact and easy to install and integrate into other optical systems. It can flexibly adapt to different application scenarios and test requirements, has high versatility, and is suitable for optical test scenarios such as flow cytometers that require high-precision focusing.

[0021] (2) In the present invention, firstly, the focus point F can be precisely adjusted from the first focus working position (horizontal position) to the second focus working position (angle θ position) by rotating the base, which can be precisely controlled to meet the needs of high-precision optical testing. For example, in a flow cytometer, it is ensured that the focus point of the laser beam is accurately aligned with the cell detection area. The adjustment of the focus point position only needs to be achieved through a single rotation of the base. The change of the angle θ directly corresponds to the movement of the focus point F, which is simpler than multi-dimensional adjustment (such as adjusting the lens angle and position). The adjustment process reduces the complexity and time cost of operation and improves the efficiency of use. In addition, the rotation connection design between the base and the bottom plate can drive the base to rotate through the driving unit, ensuring stability during rotation and reducing the influence of vibration or external interference on focusing accuracy. No additional complex mechanical structure is required. The overall design is compact, and the compactness facilitates integration into various optical systems, reducing the optical path length and system complexity. It is suitable for high-precision optical testing applications such as flow cytometers and can also meet the needs of different testing scenarios efficiently and stably. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the structure of a plane reflector structure commonly used in flow cytometers in the prior art to adjust the light path;

[0023] Figure 2 This is a schematic diagram of the working principle of the laser focusing device applied for in the present invention;

[0024] Figure 3 This is a schematic diagram of the focusing principle of the laser focusing device applied for by the present invention;

[0025] Figure 4 This is a schematic diagram of the structure of the laser focusing device applied in the present invention Figure 1 ;

[0026] Figure 5This is a schematic diagram of the structure of the laser focusing device applied in the present invention Figure 2 ;

[0027] Figure 6 This is a schematic diagram of the structure of the laser focusing device applied in the present invention Figure 3 ;

[0028] Figure 7 It is a structural schematic diagram of the focusing unit applied in the present invention. DETAILED DESCRIPTION

[0029] In the following description, a number of specific details are provided to provide a more thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention can be implemented without one or more of these details. In other examples, some technical features well known in the art are not described to avoid confusion with the present invention.

[0030] In the first aspect, a laser focusing device 10 includes: a base plate B, a base 100, a laser unit 200, a focusing unit 300 and a driving unit 400. The laser unit 200 and the focusing unit 300 are installed on the base 100. The base 100 and the base plate are rotatably connected. The laser unit 200 generates laser, the focusing unit 300 focuses the laser, and the driving unit 400 drives the base 100 to rotate to adjust the focus position of the laser beam.

[0031] In some embodiments, the base plate B serves as the supporting foundation for the entire device, and the base 100 is mounted on the base plate B and connected thereto by rotation. This design allows the base 100 to rotate relative to the base plate B, thereby providing a mechanical basis for adjusting the focal point of the laser beam. The laser unit 200 is mounted on the base 100 and is responsible for generating the laser beam. It usually includes a laser and other optical components (such as a polarizer, a beam splitter, etc.) to ensure the quality and stability of the laser beam; the focusing unit 300 is also mounted on the base 100 and is used to focus the laser beam generated by the laser unit 200. Through optical components (such as focusing mirrors, wave plates, etc.), the focusing unit 300 focuses the laser beam into a precise light spot; the driving unit 400 is responsible for driving the base 100 to rotate relative to the base plate B. By precisely controlling the rotation angle of the base 100, the driving unit 400 adjusts the focal point position of the laser beam.

[0032] In the application of the present invention, firstly, the driving unit 400 can perform high-precision control on the rotation of the base 100, so that the adjustment of the focal point position of the laser beam can reach the precision of micron level, meeting the requirements of high-precision applications. Compared with the traditional optical path system that requires multi-dimensional adjustment, the laser device can adjust the focal point position through a single rotation of the base 100, which is simpler to operate and has fewer adjustment dimensions. In addition, the rotational connection design between the base 100 and the bottom plate B, combined with the precise drive control of the driving unit 400, ensures the stability of the laser focusing device during the adjustment process and reduces the influence of vibration or external interference on the accuracy. The laser unit 200, the focusing unit 300 and the driving unit 400 are integrated on the base 100, making the device compact in structure and easy to install and integrate into other optical systems. It can flexibly adapt to different application scenarios and test requirements, has high versatility, and is suitable for optical test scenarios that require high-precision focusing, such as flow cytometers.

[0033] Optionally, the rotation center of the base 100 and the bottom plate is O, the focal point of the laser beam is F, and the laser focusing device 10 includes a first focusing working position F1 and a second focusing working position F2. When the laser focusing device 10 works in the first focusing working position F1, the line OF connecting the rotation center and the focal point is parallel to the horizontal direction. When the laser focusing device 10 works in the second focusing working position F2, the line OF connecting the rotation center and the focal point forms an angle θ with the horizontal direction, 0°<θ≤10°.

[0034] In some embodiments, the base 100 and the bottom plate B can be rotatably connected through a hinge, the hinge includes a rotation center O, the base 100 can rotate around the rotation center O, the laser unit 200 and the focusing unit 300 are installed on the base 100, the laser unit 200 generates a laser beam, the focusing unit 300 focuses the laser beam to a focal point F, and the driving unit 400 drives the base 100 to rotate, thereby changing the position of the focal point F.

[0035] In some embodiments, in the first focusing working position F1, the line OF connecting the rotation center O and the focal point F is parallel to the horizontal direction (i.e., the angle is 0°). At this time, the focal point F of the laser beam is located at a specific position in the horizontal direction, usually the initial or reference position, which is used to align with the target (such as the cell detection area in the flow cytometer); in the second focusing working position F2, the base 100 rotates around the rotation center O so that the line OF connecting the rotation center O and the focal point F forms an angle of 0°<θ≤10° with the horizontal direction. The formation of the angle θ means that the position of the focal point F has shifted and moved to a new position vertically or diagonally to adapt to different test requirements or target positions.

[0036] In the application of the present invention, firstly, through the rotation of the base 100, the focus point F can be precisely adjusted from the first focus working position F1 (horizontal position) to the second focus working position F2 (angle θ position), which can be precisely controlled to meet the needs of high-precision optical testing. For example, in a flow cytometer, to ensure that the focus point of the laser beam is accurately aligned with the cell detection area, the adjustment of the focus point position only needs to be achieved through a single rotation of the base 100. The change in angle θ directly corresponds to the movement of the focus point F, which is simpler than multi-dimensional adjustment (such as adjusting the lens angle and position). The adjustment process reduces the operation complexity and time cost, and improves the use efficiency; in addition, the rotational connection design between the base 100 and the bottom plate B ensures stability during the rotation process through the precise control of the drive unit 400, reduces the influence of vibration or external interference on the focusing accuracy, does not require additional complex mechanical structure, and the overall design is compact. The compactness facilitates integration into various optical systems, reduces the optical path length and system complexity, is suitable for high-precision optical testing applications such as flow cytometers, and can also efficiently and stably meet the needs of different testing scenarios.

[0037] Optionally, the laser unit 200 includes a light source L, a polarizer 201, a spectrometer 202, a filter 203, and a detector 204. The laser beam generated by the light source L passes through the polarizer 201 to form a linearly polarized beam. The spectrometer 202 divides the linearly polarized beam into transmitted light and reflected light. The transmitted light passes through the filter 203 to filter out stray light, and the detector 204 monitors the intensity of the reflected light.

[0038] In some embodiments, light source L is the core of laser unit 200, responsible for generating the laser beam. Light source L is typically a laser (such as a semiconductor laser or solid-state laser), which generates monochromatic laser light of a specific wavelength through electrical excitation or optical pumping. Lasers have high monochromaticity, high directionality, and high brightness, making them suitable for applications requiring micron-scale focusing, such as flow cytometry. The laser beam emitted by light source L serves as input for subsequent optical path adjustments.

[0039] In some embodiments, the polarizer 201 is used to adjust the polarization state of the laser beam into a linearly polarized beam (i.e., linearly polarized light). After the laser beam is emitted from the light source L, its polarization state may be disordered (partially polarized or unpolarized). The polarizer 201 (typically a polarizer or a polarizing prism) converts the laser beam into linearly polarized light by selectively transmitting the electric field component in a certain direction. In flow cytometers, the control of polarization is crucial to the accuracy of subsequent spectrometry and detection, as certain optical components (such as the spectrometer) are sensitive to the polarization state.

[0040] In some embodiments, the optical splitter 202 splits the linearly polarized light beam into two parts, one part for the main optical path (continued to be transmitted to the focusing system), and the other part for monitoring. Specifically, the optical splitter 202 (usually a partial reflector or a beam splitter) splits the linearly polarized light beam into transmitted light and reflected light in a certain ratio (such as 90:10 or 50:50). The transmitted light continues to propagate along the main optical path for subsequent focusing and testing; the reflected light is guided to the detector for real-time monitoring of the intensity and stability of the laser. The optical splitter realizes the separation of the optical path, which not only ensures the function of the main optical path, but also provides a feedback signal through the monitoring optical path, which helps to adjust the stability of the laser.

[0041] In some embodiments, the filter 203 is used to filter out unwanted wavelength components to ensure the monochromaticity and purity of the laser. The filter 203 (usually a bandpass filter or a narrowband filter) only allows light of a specific wavelength to pass through, filtering out stray light or background light. For example, if the laser wavelength emitted by the light source L is 488nm, the filter 203 will filter out wavelength components other than 488nm to reduce noise interference. In a flow cytometer, the laser needs to be focused to the micron level, and any stray light will affect the spot quality and test accuracy. The filter ensures the purity of the light path.

[0042] In some embodiments, the detector 204 is used to monitor the intensity of the light beam separated by the spectrometer and provide a feedback signal. The detector 204 may include a photodiode (PD) or an avalanche photodiode (APD). When the spectrometer 202 guides part of the laser light to the detector 204, the detector 204 can convert the optical signal into an electrical signal, and its output current or voltage is proportional to the intensity of the incident light. By monitoring the electrical signal, the power stability, polarization state or optical path deviation of the laser can be understood in real time. The feedback signal of the detector 204 can be used to adjust the output power of the light source L or the angle of the polarizer 201 to ensure the stability of the main optical path, especially in scenarios where the light spot deviation will cause signal attenuation (such as flow cytometers).

[0043] In some embodiments, the laser unit may also include a thermoelectric cooler (TEC) module to strictly regulate and control the internal temperature of the laser unit to ensure the stability of the output spot size and energy. Thermoelectric cooling modules are widely used in optical equipment that requires high stability. For example, in flow cytometers, the laser needs to work stably for a long time to support the continuous detection of a large number of cells. The TEC ensures the reliability of the laser output and the repeatability of the test results. Similarly, in laser interferometers and spectrometers, the temperature control of the TEC also significantly improves the measurement accuracy.

[0044] In the present application, first, laser light is emitted by the light source L, the polarizer 201 adjusts the polarization, the spectrometer 202 separates the light path, the filter 203 purifies the wavelength, and the detector 204 monitors the light intensity, ultimately providing a stable laser beam for the main light path, while achieving real-time feedback by monitoring the light path; in addition, the optical unit ensures the polarization state, wavelength purity and intensity stability of the laser beam through the coordinated work of the polarizer, spectrometer and filter, providing a reliable light source for micron-level focusing, and providing a guarantee for the stability and reliability of the light path adjustment; in addition, the real-time monitoring function of the detector can timely detect light spot offset or power fluctuation, and adjust the light source or light path elements in combination with the feedback control system to maintain test accuracy. The laser in the main light path can continue to be transmitted to the focusing lens seat (such as the focusing system in the flow cytometer), which can achieve micron-level focusing for applications such as testing cell size.

[0045] Optionally, the focusing unit 300 includes an angle plate 301, an angle plate holder 304, a wave plate 302, a focusing lens 303, a lens base 304, a locking piece 305, a focusing lens barrel 306, and a locking ring 307. The angle plate 301 is installed on the angle plate holder 304, the angle plate holder 304 and the wave plate 302 are installed on the lens base 304, the locking piece 305 locks the focusing lens barrel 306, the focusing lens 303 is installed on the focusing lens barrel 306, and the locking ring 307 is installed on the focusing lens barrel 306.

[0046] In some embodiments, the angle plate 301 is mounted on an angle plate holder 304. The plug-in angle plate holder 304 facilitates the replacement of angle plates of varying specifications. After the light beam enters the focusing unit from the laser unit, the angle plate 301 adjusts the beam's angle, ensuring it enters the subsequent optical components in the correct direction. The angle plate holder 304 acts as a bracket, mounting the angle plate 301 and maintaining its stability. By fine-tuning the beam's propagation direction, the angle plate 301 corrects optical path deviations, ensuring precise alignment of the beam with the subsequent wave plate 302 and focusing lens 303.

[0047] In some embodiments, a wave plate 302 is mounted on a lens mount 304. Wave plate 302 is used to alter the polarization state of a light beam, for example, converting linearly polarized light to circularly polarized light or adjusting the polarization direction. Wave plate 302 can adjust the polarization properties of a light beam by introducing a phase delay (e.g., a quarter-wave plate or half-wave plate). This function is particularly important in applications requiring a specific polarization, such as improving the sensitivity and specificity of flow cytometers.

[0048] In some embodiments, focusing lens 303 is mounted on focusing lens barrel 306. Focusing lens 303 is a lens that converges the incident light beam to a specific focal point, forming a small light spot. Lens mount 304 secures the focusing lens, ensuring its stable position. Focusing lens 303 uses its curvature and refractive index to focus the parallel light beam to the target location. The size and position of the light spot are determined by the design of the focusing lens and are the core steps in achieving high-precision focusing.

[0049] In some embodiments, the focusing lens barrel 306 is mounted on the angle piece holder 304 via a locking member 305. The locking member 305 locks the focusing lens barrel 306, which can be a locking screw. The focusing lens barrel 306 accommodates and protects the focusing lens 303. For example, the focusing lens barrel 306 is provided with a precision guide cylinder and precision matching threads to achieve axial fine adjustment. After the focusing lens 303 is adjusted, it is locked using a locking ring 307, which locks the components within the focusing lens barrel. These components use mechanical structures (such as threads or clamps) to ensure that all optical components do not move or loosen during operation, thereby maintaining system stability and focusing accuracy.

[0050] In the present application, firstly, the angle plate 301 and the wave plate 302 ensure that the light beam enters the focusing lens 303 at the optimal angle and polarization state, which can achieve micron-level focusing accuracy and can be applied to application scenarios such as flow cytometers to meet the needs of high-precision focusing for accurate detection of cell parameters. The design of the lens base 304, the locking piece 305, the focusing lens barrel 306 and the locking ring 307 makes the position of the optical elements firm, reduces the errors caused by vibration or temperature changes, and ensures the reliability and consistency of the long-term operation of the system; in addition, the angle plate 301 and the wave plate 302 allow the user to adjust the beam angle and polarization state according to needs, adapting to a variety of application scenarios, so that the focusing unit 300 has good flexibility and can be used for different optical testing needs, which increases the scope of application. The design of the focusing barrel 306 and the locking ring 307 facilitates the installation and replacement of optical components, reducing maintenance costs and time. In addition, the focusing unit 300 realizes the angle adjustment, polarization control and high-precision focusing of the light beam through the coordinated action of components such as the angle plate 301, the wave plate 302 and the focusing mirror 303. The component layout of the focusing unit 300 is compact, occupies a small space, and is easy to integrate into various optical systems. The compactness reduces the optical path length and system complexity, while improving the stability of the laser focusing device, which is very suitable for application scenarios requiring high-precision optics such as flow cytometers.

[0051] Optionally, the laser focusing device also includes a connecting unit, which includes a connecting member 501, a fixed block 502, a first fixing member 503, a first spring 504, a second fixing member 505, and a second spring 506. The base 100 is connected to the bottom plate P through the connecting member 501, the fixed block 502 is connected to the bottom plate P, one end of the first spring 504 is connected to one side of the first fixing member 503, the other end of the first spring 504 is connected to one side of the second fixing member 505, the other side of the first fixing member 503 is connected to the fixed block 502, the other side of the second fixing member 505 is connected to the base 100, and the second spring 506 presses the base.

[0052] In some embodiments, the base 100 serves as one of the foundations of the entire device, supporting the laser unit and the focusing unit, and is movably connected to the base plate P through the connecting member 501, so that the base 100 can move relative to the base plate. The connecting member 501 can be a screw, and the second spring 506 can be sleeved on the connecting member 501, and the second spring 506 can press the base 100.

[0053] In some embodiments, the fixed block 502 is connected to the base plate P and serves as an anchor point of the connection unit, providing a fulcrum for the spring system. The spring system includes a first spring 504, one end of the first spring 504 is connected to one side of the first fixing member 503, and the other end is connected to one side of the second fixing member 505. One side of the first fixing member 503 is connected to the fixed block 502, and the other side is connected to the second fixing member 505 through the first spring 504, which plays a role in transmitting force and fixing. One side of the second fixing member 505 is connected to the first fixing member 503 through the first spring 504, and the other side is connected to the base 100, completing the connection closed loop of the spring system. The second spring 506 presses against the base to reduce or prevent the base from displacing in a direction perpendicular to the plane of the base, thereby ensuring that the base and the base rotate with the rotation center O of the base 100 and the base as O (i.e., rotational connection). The spring system (including the first spring 504) provides elastic support, so that the base 100 can automatically return to the predetermined position through the return function of the spring after adjustment.

[0054] In the present application, first, the base 100 is movably connected to the bottom plate P through the connecting member 501 (for example, through screws), allowing the base 100 to be rotated and adjusted relative to the bottom plate P, thereby realizing high-precision alignment of the laser focusing device. In particular, in applications requiring micron-level focusing (such as flow cytometers), the dynamic adjustment and return functions ensure the precise alignment of the optical path and reduce errors caused by manual adjustment. In addition, the connecting unit adopts a modular design, and components such as the connecting member 501, the fixing block 502, the first fixing member 503, and the second fixing member 505 are easy to disassemble and replace, which simplifies the maintenance process, reduces maintenance costs and downtime, and improves the reliability and service life of the device. In addition, the component layout of the connecting unit is compact and occupies little space. The fixing block 502 and the spring system are reasonably designed, which reduces the overall volume. The compactness makes the connecting unit easy to integrate into various optical systems, reduces the optical path length and system complexity, and improves the portability and stability of the laser focusing device.

[0055] Optionally, the drive unit 400 includes a brake 401, a motor 402, a screw 406, a nut block, a movable plate 403, a push rod 404, a spring 405, and an encoder 407. The drive unit 400 is installed on the base plate. The motor 402 drives the screw 406 to rotate, and the rotation of the screw 406 drives the nut block to move. The encoder 407 is connected to the screw 406. The encoder 407 is connected to the base plate through the mounting plate. The spring 405 is located between the movable plate 403 and the mounting plate. The spring 405 presses the movable plate 403 so that the movable plate 403 contacts the nut block. The push rod 404 is installed on the movable plate 403. The push rod 404 pushes the base 100 to rotate.

[0056] In some embodiments, motor 402 serves as a power source, driving screw 406 to rotate. Screw 406 and the nut block form a screw-nut pair. The rotational motion of the screw is converted into linear motion of the nut block. Motor 402 (typically a stepper motor or servo motor) is controlled by electrical signals to rotate, driving screw 406. The threaded design of screw 406 enables the nut block to move along the screw axis, thereby achieving precise linear displacement.

[0057] In some embodiments, after the linear movement of the nut block, the spring drives the movable plate 403 to move. The spring 405 is located between the movable plate 403 and the mounting plate, pressing the movable plate 403 so that it maintains close contact with the nut block. The spring 405 provides elastic force to eliminate the gap between the nut block and the movable plate. The push rod 404 is installed on the movable plate 403. The push rod 404 moves with the movable plate. The push rod 404 transmits its displacement to the base, so that the base rotates about the rotation center O of the base 100 and the bottom plate (i.e., rotational connection), thereby realizing precise adjustment of the optical path.

[0058] In some embodiments, encoder 407 is connected to lead screw 406 and fixed to the base plate via a mounting plate. This encoder is used to monitor the lead screw's rotation angle and position in real time. Encoder 407 (typically a photoelectric encoder or an absolute encoder) detects the rotation angle of lead screw 406, calculates the displacement of the nut block, and feeds this position signal back to the laser focusing device's control system. The control system then adjusts the operation of motor 402 based on this feedback signal, achieving closed-loop control and ensuring the precise position of movable plate 403.

[0059] In some embodiments, brake 401 is used to lock lead screw 406 when the motor is stopped to prevent accidental movement. Brake 401 (typically an electromagnetic brake) activates when the motor is powered off or stopped, locking lead screw 406 and ensuring that the position of the nut block and movable plate 403 is not changed by external forces (such as gravity or vibration), thus ensuring stability when the system is stopped.

[0060] In the present application, first, the motor 402 drives the lead screw 406 and the nut block to achieve precise linear motion, and the encoder 407 provides real-time position feedback to form a closed-loop control system. The closed-loop control system of the encoder 407 supports automatic adjustment, and the coordinated work of the motor 402 and the brake 401 reduces manual intervention. The high-precision motion control ensures that the displacement of the push rod 404 is accurate to the micron level, meeting the high-precision requirements for optical path adjustment in applications such as flow cytometers; in addition, the spring 405 eliminates the gap between the nut block and the moving plate 403, and the brake 401 locks the lead screw 406 when stopped to prevent accidental displacement, ensuring that the motor 402 will not be displaced by vibration or external force in both running and stopped states, thereby enhancing the reliability of the laser focusing device. The component layout of the drive unit 400 is compact, the mounting plate is fixed to the base plate, the overall structure occupies a small space, and the compact design is convenient for integration into various optical systems, reducing the optical path length and system complexity, and improving overall stability.

[0061] Optionally, along the first direction, at the first focusing working position F1, the distance from the push rod to the rotation center O is L1, and the distance from the focusing point F to the rotation center O is L2; at the second focusing working position F2, along the second direction, the distance the push rod moves is H2, and the distance the focusing point moves is H1, satisfying: H1 / H2=L1 / L2.

[0062] In some embodiments, the first direction is the horizontal direction X, the second direction is the vertical direction Y, and the third direction is the height direction of the laser focusing device. The third direction can also be the Z direction. The first direction, the second direction, and the third direction are perpendicular to each other, that is, they all form a 90° angle.

[0063] In the present invention application, firstly, the position of the focus point can be accurately adjusted by moving the push rod, ensuring that the laser focus point can be accurately aligned with the target position. The movement of the push rod is in a fixed ratio with the movement of the focus point, and the operation is intuitive and simple. Compared with the traditional optical path adjustment (such as adjusting the angle and position of multiple lenses), this design only needs to control one dimension of the push rod, which reduces the complexity of operation and the learning cost. The operator can achieve precise positioning of the focus point with a single action, which improves efficiency. In addition, the movement relationship between the push rod and the focus point is fixed by the mechanical structure, avoiding the cumulative error that may be introduced by multi-dimensional adjustment, reducing the optical path length and the number of components, making the device more compact and easy to integrate into various optical systems. After the adjustment is completed, the laser focusing device can maintain a stable focus position, reducing the deviation caused by external interference, and can achieve automatic focus by precisely controlling the movement of the push rod. It is suitable for a variety of laser focusing test scenarios, such as industrial laser processing or optical experiments in scientific research.

[0064] Optionally, the focus point movement accuracy Q is:

[0065] Q=MAX(P / N*L2 / L1,P*T1 / 360*L2 / L1).

[0066] Where P is the ball screw lead, N is the number of subdivisions of the motor driver, and T1 is the encoder accuracy in degrees.

[0067] In some embodiments, the laser focusing device drives the base to rotate through a driving unit (including a motor, a ball screw, etc.), and the movement of the push rod is realized by the motor driving the ball screw. The ball screw converts the rotational motion of the motor into linear motion, thereby adjusting the position of the focal point F of the laser beam. The rotation of the base is based on the lever principle. The focus point movement accuracy Q represents the theoretical value of the focus point movement accuracy, which is limited by the motor driver subdivision and encoder accuracy. The larger value of the two is taken. P / N*L2 / L1 represents the contribution of the motor driver subdivision accuracy to the focus point movement. P*T1 / 360*L2 / L1 represents the contribution of the encoder accuracy limitation to the focus point movement. The larger value of the two is taken, which reflects the most important accuracy limiting factor of the laser focusing device.

[0068] In the present application, firstly, the focus point movement accuracy Q is comprehensively considered through the formula of the ball screw lead P, the motor subdivision number N, the encoder accuracy T1 and the lever ratio L2 / L1, so as to ensure that the focus point movement reaches the micron level accuracy, meet the high-precision optical test requirements of flow cytometers, etc., and ensure that the focus point is accurately aligned with the target position. The MAX function is used to select the larger limit of the motor driver subdivision number and the encoder accuracy to ensure that the precision design fully considers the focusing bottleneck of the laser focusing device; in addition, the calculation of the focus point movement accuracy Q provides a theoretical basis for autofocus. By adjusting the ball screw lead P, the subdivision number N, the encoder accuracy T1 or the lever ratio L2 / L1, the focus point movement accuracy Q can be flexibly optimized, and then the accuracy can be adjusted according to different application requirements, adapting to a variety of laser focusing test scenarios, and improving the versatility of the laser focusing device.

[0069] Alternatively, in some embodiments, the focus point movement accuracy Q is:

[0070] Q=(P / N*L2 / L1+P*T1 / 360*L2 / L1) / 2

[0071] In some embodiments, the contribution of the motor driver's subdivision accuracy to the focus point movement and the contribution of the encoder's accuracy limitation to the focus point movement can be averaged. The formula also incorporates the influence of the mechanical structure's step-by-step accuracy and the accuracy of the angle control during operation. The focus point movement accuracy is determined by comprehensive consideration, so that the optimized or balanced focus point movement accuracy can be found.

[0072] In a second aspect, the present invention provides a laser focusing device method, which may or may not employ the laser focusing device described in any one of the first aspects above, comprising:

[0073] Step S100, when the laser focusing device 10 is working in the first focusing position F1, the line OF connecting the rotation center and the focus point is parallel to the horizontal direction;

[0074] In step S200, the driving unit 400 drives the base to rotate relative to the bottom plate, adjusting the focus position of the laser beam to switch from the first focusing position to the second focusing position;

[0075] In step S300 , when the laser focusing device 10 is working in the second focusing position F2 , the line OF connecting the rotation center and the focus point forms an angle θ with the horizontal direction, 0°<θ≤10°.

[0076] In some embodiments, in the first focusing working position F1, the line OF connecting the rotation center O and the focal point F is parallel to the horizontal direction (i.e., the angle is 0°). At this time, the focal point F of the laser beam is located at a specific position in the horizontal direction, usually the initial or reference position, which is used to align with the target (such as the cell detection area in the flow cytometer); in the second focusing working position F2, the base 100 rotates around the rotation center O so that the line OF connecting the rotation center O and the focal point F forms an angle θ (0°<θ≤10°) with the horizontal direction. The formation of the angle θ means that the position of the focal point F has shifted and moved to a new position in the vertical direction or diagonally to adapt to different test requirements or target positions.

[0077] In the application of the present invention, firstly, through the rotation of the base 100, the focus point F can be accurately adjusted from the first focus working position F1 (horizontal position) to the second focus working position F2 (angle θ position), which can be precisely controlled to meet the needs of high-precision optical testing. For example, in a flow cytometer, to ensure that the focus point of the laser beam is accurately aligned with the cell detection area, the adjustment of the focus point position only needs to be achieved through a single rotation of the base 100. The change in angle θ directly corresponds to the movement of the focus point F, which is simpler than multi-dimensional adjustment (such as adjusting the lens angle and position). The adjustment process reduces the operation complexity and time cost and improves the use efficiency; in addition, the rotation connection design between the base 100 and the bottom plate B can drive the base to rotate through the drive unit 400, ensuring stability during rotation and reducing the influence of vibration or external interference on focusing accuracy. No additional complex mechanical structure is required. The overall design is compact, and the compactness facilitates integration into various optical systems, reducing the optical path length and system complexity. It is suitable for high-precision optical testing applications such as flow cytometers, and can also efficiently and stably meet the needs of different testing scenarios.

[0078] Optionally, along the first direction, at the first focusing working position F1, the distance from the push rod to the rotation center O is L1, and the distance from the focusing point F to the rotation center O is L2; at the second focusing working position F2, along the second direction, the distance the push rod moves is H2, and the distance the focusing point moves is H1, satisfying: H1 / H2=L1 / L2.

[0079] In some embodiments, H1 / H2=L1 / L2 can refer to the technical content, technical solutions and technical effects of H1 / H2=L1 / L2 in the first aspect, and the present application will not repeat them.

[0080] Optionally, step S200: the motor 402 drives the lead screw 406 to rotate, and the rotational motion of the lead screw is converted into the linear motion of the nut block. The spring 405 is located between the movable plate 403 and the mounting plate. The spring 405 presses the movable plate 403 to keep it in close contact with the nut block. The spring 405 provides elastic force to eliminate the gap between the nut block and the movable plate. After the linear motion of the nut block, the spring 405 drives the movable plate 403 to move. The push rod 404 is installed on the movable plate 403. The push rod 404 moves with the movable plate 403. The push rod 404 transmits its displacement to the base, so that the base 100 rotates about the rotation center O of the base 100 and the bottom plate.

[0081] In some embodiments, the driving unit 400 includes a brake 401, a motor 402, a screw 406, a nut block, a movable plate 403, a push rod 404, a spring 405, and an encoder 407. The driving unit 400 is installed on the base plate. The motor 402 drives the screw 406 to rotate, and the rotation of the screw 406 drives the nut block to move. The encoder 407 is connected to the screw 406. The encoder 407 is connected to the base plate through the mounting plate. The spring 405 is located between the movable plate 403 and the mounting plate. The spring 405 presses the movable plate 403 so that the movable plate 403 contacts the nut block. The push rod 404 is installed on the movable plate 403. The push rod 404 pushes the base 100 to rotate. The driving unit 400 can be used The moving unit 400 drives the base to rotate relative to the base plate, specifically including: the motor 402 drives the lead screw 406 to rotate, the rotational motion of the lead screw is converted into the linear motion of the nut block, the spring 405 is located between the moving plate 403 and the mounting plate, the spring 405 presses the moving plate 403 to keep it in close contact with the nut block, the spring 405 provides elastic force to eliminate the gap between the nut block and the moving plate, after the linear motion of the nut block, the spring 405 drives the moving plate 403 to move, the push rod 404 is installed on the moving plate 403, the push rod 404 moves with the moving plate 403, and transmits the displacement to the base, so that the base 100 rotates with the rotation center of the base 100 and the base plate as O.

[0082] In some embodiments, the motor 402 drives the screw 406 to rotate, and the rotational motion of the screw is converted into precise linear motion through the nut block. The nut block drives the movable plate 403 and the push rod 404 to move, and finally drives the base 100 to rotate. The screw-nut mechanism has high transmission accuracy, and with the precise control of the motor 402, it can achieve micron-level displacement adjustment, ensuring the accuracy of the rotation angle of the base 100, thereby accurately controlling the focus position.

[0083] In some embodiments, spring 405 is positioned between movable plate 403 and the mounting plate, pressing against movable plate 403 to maintain close contact with the nut block and eliminate any gap between them. The elastic force of spring 405 ensures stable motion transmission, preventing displacement errors or vibrations caused by gaps, and improving system reliability, particularly in high-precision optical testing.

[0084] In the present invention, first, the rotational motion is converted into linear motion through the screw-nut mechanism, and then transmitted to the base 100 through the push rod 404, thereby realizing a single rotation adjustment of the base. Compared with traditional multi-dimensional adjustment (such as adjusting the angle and position of the lens), this design only needs to control the rotation of the motor 402 to achieve focus adjustment, which is simpler to operate and reduces the complexity and time cost of adjustment. The drive unit 400 adopts a combination of the screw-nut mechanism and the push rod 404, which has a compact structure and high transmission efficiency. The compact design is easy to integrate into the laser focusing device, reducing the optical path length and system complexity. At the same time, the efficient transmission improves energy utilization. In addition, the movement of the motor 402 driving the screw 406 can be automated through the control system. In combination with the encoder, closed-loop control can be formed to further improve the accuracy. No complex electronic control system is required, which reduces the overall cost and makes the device more competitive in the market for application scenarios such as flow cytometry.

[0085] Optionally, the focus point movement accuracy Q is:

[0086] Q=MAX(P / N*L2 / L1,P*T1 / 360*L2 / L1).

[0087] Where P is the ball screw lead, N is the number of subdivisions of the motor driver, and T1 is the encoder accuracy in degrees.

[0088] In the present application, firstly, the focus point movement accuracy Q comprehensively considers the ball screw lead P, motor subdivision number N, encoder accuracy T1 and lever ratio L2 / L1 through a formula to ensure that the focus point movement reaches micron-level accuracy, meets the high-precision optical test requirements of flow cytometers, etc., and ensures that the focus point is accurately aligned with the target position. The MAX function is used to select the larger restrictions of the motor driver subdivision number and encoder accuracy to ensure that the precision design fully considers the focusing bottleneck of the laser focusing device; in addition, the calculation of the focus point movement accuracy Q provides a theoretical basis for autofocus. By adjusting the ball screw lead P, subdivision number N, encoder accuracy T1 or lever ratio L2 / L1, the focus point accuracy Q can be flexibly optimized, and then the accuracy can be adjusted according to different application requirements, adapting to a variety of laser focusing test scenarios, and improving the versatility of the laser focusing device.

[0089] Alternatively, in some embodiments, the focus point movement accuracy Q is:

[0090] Q=(P / N*L2 / L1+P*T1 / 360*L2 / L1) / 2

[0091] In some embodiments, the contribution of the motor driver's subdivision accuracy to the focus point movement and the contribution of the encoder's accuracy limitation to the focus point movement can be averaged. The formula also incorporates the influence of the mechanical structure's step-by-step accuracy and the accuracy of the angle control during operation. The focus point movement accuracy is determined by comprehensive consideration, so that the optimized or balanced focus point movement accuracy can be found.

[0092] Those skilled in the art can understand that the various operations, methods, steps in the process, measures, and schemes discussed in the present invention application can be interchanged, changed, combined, or deleted; further, the various operations, methods, and other steps, measures, and schemes in the process discussed in the present invention application can also be interchanged, changed, rearranged, decomposed, combined, or deleted; further, the various operations, methods, and steps in the process disclosed in the present invention application in the prior art can also be interchanged, changed, rearranged, decomposed, combined, or deleted. The various technical features of the above embodiments can be arbitrarily combined. To make the description concise, not all possible combinations of the various technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification;

[0093] The embodiments described above only express several implementation methods of the embodiments of the present disclosure, and their descriptions are relatively specific and detailed, but they cannot be understood as limiting the patent scope of the embodiments of the present disclosure; it should be pointed out that for ordinary technicians in this field, without departing from the concept of the embodiments of the present disclosure, several variations and improvements can be made, which all fall within the protection scope of the embodiments of the present disclosure; therefore, the protection scope of the embodiments of the present disclosure should be based on the attached claims. As mentioned above, although the present invention application has been expressed and described with reference to specific preferred embodiments, it shall not be interpreted as limiting the present invention application itself. Various changes can be made to it in form and detail without departing from the spirit and scope of the present invention application defined in the attached claims.

Claims

1. A laser focusing device, characterized in that: include: The base plate, the pedestal, the laser unit, the focusing unit and the driving unit are installed on the base. The base and the base plate are rotatably connected. The laser unit generates laser, the focusing unit focuses the laser, and the driving unit drives the base to rotate to adjust the focus position of the laser beam.

2. A laser focusing device according to claim 1, characterized in that: The rotation center of the base and the bottom plate is O, the focal point of the laser beam is F, and the laser focusing device includes a first focusing working position and a second focusing working position. When the laser focusing device works in the first focusing working position, the line OF connecting the rotation center and the focal point is parallel to the horizontal direction. When the laser focusing device works in the second focusing working position, the line OF connecting the rotation center and the focal point forms an angle θ with the horizontal direction, 0°<θ≤10°.

3. The laser focusing device according to claim 2, characterized in that: The laser unit includes a light source, a polarizer, a spectrometer, a filter, and a detector. The light source generates a laser beam, which passes through the polarizer to form a linearly polarized beam. The spectrometer divides the linearly polarized beam into transmitted light and reflected light. The transmitted light passes through the filter to filter out stray light, and the detector monitors the intensity of the reflected light.

4. The laser focusing device according to claim 3, characterized in that: The focusing unit includes an angle plate, an angle plate holder, a wave plate, a focusing lens, a lens base, a locking piece, a focusing lens barrel, and a locking ring. The angle plate is installed on the angle plate holder, the angle plate holder and the wave plate are installed on the lens base, the locking piece locks the focusing lens barrel, the focusing lens is installed on the focusing lens barrel, and the locking ring is installed on the focusing lens barrel.

5. The laser focusing device according to claim 4, characterized in that: The laser focusing device also includes a connecting unit, which includes a connecting member, a fixed block, a first fixing member, a first spring, a second fixing member, and a second spring. The base is connected to the bottom plate through the connecting member, the fixed block is connected to the bottom plate, one end of the first spring is connected to one side of the first fixing member, the other end of the first spring is connected to one side of the second fixing member, the other side of the first fixing member is connected to the fixed block, the other side of the second fixing member is connected to the base, and the second spring presses the base.

6. The laser focusing device according to claim 5, characterized in that: The driving unit includes a brake, a motor, a screw, a nut block, a movable plate, a push rod, a spring, and an encoder. The driving unit is installed on the base plate. The motor drives the screw to rotate, and the rotation of the screw drives the nut block to move. The encoder is connected to the screw, and the encoder is connected to the base plate through the mounting plate. The spring is located between the movable plate and the mounting plate. The spring presses the movable plate so that the movable plate contacts the nut block. The push rod is installed on the movable plate, and the push rod drives the base to rotate.

7. The laser focusing device according to claim 6, characterized in that: Along the first direction, in the first focusing working position, the distance from the push rod to the rotation center O is L1, and the distance from the focusing point F to the rotation center O is L2; in the second focusing working position, along the second direction, the distance moved by the push rod is H2, and the distance moved by the focusing point is H1, satisfying: H1 / H2=L1 / L2.

8. A laser focusing method, which uses a laser focusing device according to any one of claims 2 to 6, characterized in that: include: Step S100, when the laser focusing device is working in the first focusing working position, the line OF connecting the rotation center O of the base and the bottom plate and the focusing point F is parallel to the horizontal direction; Step S200: The driving unit drives the base to rotate relative to the base plate to adjust the focus position of the laser beam to switch from the first focusing position to the second focusing position. Step S300: When the laser focusing device is working in the second focusing position F2, the line OF connecting the rotation center and the focus point forms an angle θ with the horizontal direction, 0°<θ≤10°.

9. The laser focusing device operating method according to claim 8, characterized in that: Along the first direction, in the first focusing working position, the distance from the push rod to the rotation center O is L1, and the distance from the focusing point F to the rotation center O is L2; in the second focusing working position, along the second direction, the distance moved by the push rod is H2, and the distance moved by the focusing point is H1, satisfying: H1 / H2=L1 / L2.

10. The laser focusing device operating method according to claim 8, characterized in that: Step S200 includes: the motor drives the lead screw to rotate, and the rotational motion of the lead screw is converted into the linear motion of the nut block. The spring is located between the movable plate and the mounting plate. The spring presses the movable plate to keep it in close contact with the nut block. The spring provides elastic force to eliminate the gap between the nut block and the movable plate. After the linear motion of the nut block, the spring drives the movable plate to move. The push rod is installed on the movable plate, and the push rod moves with the movable plate. The push rod transmits its displacement to the base, so that the base rotates about the rotation center of the base and the bottom plate.

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