60results about How to "Improve focus accuracy" patented technology

The invention discloses a projector automatic focusing method based on a spectrum sensor and related equipment, and the method comprises the steps: carrying out the wavelength decomposition of a reflected light signal, and obtaining a light intensity value; calculating an initial distance value between the projector and the projection surface; carrying out integral operation on the acceleration data and the angular velocity data to obtain a position offset and an attitude angle offset; determining a compensation distance, and calculating an actual projection distance; controlling a stepping motor to drive a lens assembly to move to a focusing position corresponding to the target focal length value; controlling a stepping motor to drive a lens assembly to reciprocate; a new reflected light signal is collected again after each reciprocating motion; processing the new reflected light signal based on a preset mapping model to obtain a current measurement distance; and when the deviation value between the current measurement distance and the preset optimal imaging distance is smaller than a preset threshold value for the first time, determining the focusing position corresponding to the final measurement distance as a final focusing position. The automatic focusing precision of the projector is improved, and the definition of a projection picture is further improved.

The utility model belongs to the technical field of water turbine machining, and particularly relates to a robot relief grinding water turbine fixed guide vane tool which comprises a first adjusting mechanism and a second adjusting mechanism, the first adjusting mechanism and the second adjusting mechanism each comprise two bases, adjusting plates are vertically installed on the two bases, sliding supports are connected to the adjusting plates, and the sliding supports are connected to the first adjusting mechanism and the second adjusting mechanism. A bearing plate is connected between the two sliding supports, two adjusting bottom plates are symmetrically arranged on the bearing plate, and a vertically-arranged movable baffle is further arranged on the outer side of the first adjusting mechanism. The tool is suitable for robot relief grinding pumped storage and installation of the fixed guide vane of the mixed-flow water turbine. And through limiting of the tool, the number of times of manual teaching of the robot tool path is effectively reduced, and the working efficiency of automatic relief grinding of the guide vane is improved. Through limiting of the tool, the focusing accuracy of scanning of the three-dimensional camera is improved, then the optimization difficulty after the planning relief grinding path is generated is reduced, and the overall machining quality of the robot for relief grinding of the fixed guide vane is improved.

The invention discloses a simple area array detector focus fixing method adopting a single-hole scanning mode, and belongs to the field of detector image plane focus fixing. The implementation method comprises the steps that a blank screen with a small hole is placed in front of an objective lens, incident light passes through the small hole and then passes through the objective lens to form a light spot, a detector collects a light spot image, and the light spot mass center position is obtained through a mass center calculation algorithm; moving the blank screen in the vertical direction, collecting light spot images at different positions of the small hole, respectively calculating to obtain the light spot mass center position of each light spot image, comparing the light spot mass center position with the initially formed light spot mass center position, and judging whether the detector is in a pre-focus state or a post-focus state at the moment; obtaining a defocusing amount according to a defocusing amount formula; if deviation exists between the positions of the centroids, the installation position is adjusted; if the mass centers of the corresponding light spots are located at the same position of the detector before and after movement, the detector is just located on the focal plane of the objective lens, the detector is installed in place, and simple focus fixing of the area array detector is achieved. According to the invention, the positioning precision can reach one hundredth pixel.

The invention discloses a focusing method and device and a storage medium, and relates to the technical field of video image focusing, and the method comprises the steps: determining a to-be-focused target block in a current frame of video data and a plurality of target sub-blocks in the target block, and obtaining a to-be-focused region set, each target sub-block being obtained through the division of the target block; an image original pixel of the target block is acquired, a phase difference value of each to-be-focused area in the to-be-focused area set is determined based on the image original pixel, and each to-be-focused area comprises the target block and each target sub-block; and determining a target focusing area according to each phase difference value, and focusing the target focusing area. According to the method, the target block needing to be focused is further subjected to region division, and the phase difference values of the divided regions are evaluated, so that a better region of interest of the target block can be quickly focused in a complex scene, and the focusing efficiency and the imaging quality of the automatic focusing system are improved.

The invention provides an automatic focusing method of an imaging device and an exterior mirror system. The method comprises the following steps: acquiring a working distance between a zoom lens and an imaging target through a distance detection module; determining a focusing search range of the zoom lens according to the working distance, and determining an image acquisition step length according to the working distance and the current focusing definition; and adjusting the zoom lens according to the image acquisition step length, and searching a focusing position in the focusing search range. The working distance between the lens and the imaging target is measured through the distance detection module, the focusing search range is preliminarily locked, invalid focusing outside the focusing search range is avoided, and the focusing efficiency is improved; and the working distance is also used for setting a proper image step length in combination with the current focusing definition, so that the focusing process can cover the peak position of the image definition, the focusing success rate under the conditions of relatively shallow depth of field, relatively high image contrast curve kurtosis and the like is improved, and the situation that the automatic focusing efficiency is limited due to too small step length is avoided.

The invention relates to the technical field of automatic focusing, in particular to an optical lens automatic focusing method and system. The method comprises the following steps: scanning a three-dimensional environment on a moving path through an optical lens carried on the sweeping robot, and carrying out waste optical environment analysis to obtain waste optical environment data; performing spatial optical axis offset calculation on the waste optical environment data, and performing focus offset coefficient calculation on the waste optical environment data to obtain a waste focus offset coefficient; performing focal plane curvature change analysis according to the waste focus offset coefficient to obtain focal plane curvature change data; according to the focal plane curvature change data, focal plane multi-dimensional calibration processing is carried out, an optical lens focusing strategy is made, and the optical lens focusing strategy is obtained; and performing automatic firmware design on the optical lens focusing strategy to obtain optical lens focusing strategy firmware. According to the method, the automatic focusing technology is optimized, so that the automatic focusing technology is more perfect.

The invention discloses an automatic focusing method for nozzle annulus microscopic vision detection. The automatic focusing method comprises the following steps: constructing a nozzle annulus microscopic vision detection device; the nozzle to be detected is clamped on the nozzle ring belt microscopic visual detection device; adjusting parameters of the nozzle ring belt microscopic visual detection device to complete automatic focusing of the nozzle ring belt of the detected nozzle; and after the automatic focusing is completed, acquiring a positive focal microscopic image of the nozzle annulus through the nozzle annulus microscopic visual detection device, and outputting the positive focal microscopic image. According to the method provided by the invention, the defects of an existing automatic focusing method in the aspects of focusing window selection and light source illumination intensity setting are overcome.

The invention provides a circularly symmetric Airy beam wavefront phase modulation method based on a multi-focal-length lens. The method comprises the following steps: determining beam parameters of a CAB; calculating the self-focusing focal length d of the CAB; shielding all other light rings except the nth light ring, and solving the diffraction integral of the single light ring so as to obtain a focal length dn; the modulation focal length fn is reasonably estimated according to the difference value between the self-focusing focal length d and the single halo focal length dn, and the modulation focal length fn of each stage of halo is finely adjusted based on the obtained modulation focal length fn of each stage of halo, so that the optimal modulation effect is realized. On the premise that CAB initial light intensity distribution is not changed, higher energy concentration and better focusing characteristics are achieved, and the focusing precision of light beams is improved.

The present application provides a kind of forest tree species classification method, device, electronic equipment and storage medium, belong to artificial intelligence technical field, method includes: forest remote sensing image is input to forest tree species classification model, obtains the output tree species classification result;Forest tree species classification model includes preliminary feature processing module, high-order feature extraction module and tree species classification result output module, high-order feature extraction module is sequentially connected first residual block stack layer, first down-sampling layer, second residual block stack layer, second down-sampling layer, third residual block stack layer, third down-sampling layer and fourth residual block stack layer, stacked residual block embedding dimension rearrangement layer, dimension recovery layer and convolution block attention module.The present application improves the dimension compatibility of CBAM and convolution architecture by embedding explicit dimension rearrangement layer and dimension recovery layer in the residual block embedded with CBAM, effectively improves the classification accuracy of forest remote sensing image for forest tree species classification task.

The invention provides an array camera automatic focusing method and device and a medium, a micro stepping motor is arranged behind each camera module in an array camera, and the method comprises the following steps: the array camera and the micro stepping motors are respectively connected with a terminal device; controlling the micro stepping motor to rotate by alpha degrees from the initial position every time, obtaining a key frame of a video stream of the micro stepping motor, calculating a definition score of the key frame by adopting an image evaluation function, selecting a picture with the highest score in N pictures, recording a score value of the picture as a current highest score GK, and rotating the micro stepping motor to an angle corresponding to the GK as a current position; and then reducing the step, respectively taking one step from the left and right sides of the current position to calculate scores, taking the highest score point as the current position, continuing to reduce the step, taking the key frame in a pendulum or progressive manner according to the current position, and continuously adjusting the current optimal position until the key frame cannot rotate, thereby completing focusing. According to the invention, efficient, automatic and accurate focusing of the array camera can be realized, and combination of manual fine tuning is supported.

The utility model relates to the field of laser devices, in particular to a laser shell and laser equipment, and the laser shell comprises an outer shell and a focus fixing assembly. The shell is provided with an output end used for outputting laser, and the shell is provided with an adjusting groove adjacent to the output end and a positioning groove communicated with the adjusting groove. The focus fixing assembly comprises a focus fixing rod and a fixing part, the focus fixing rod is in sliding connection with the adjusting groove and located in the adjusting groove, the fixing part is in sliding connection with the positioning groove, and the fixing part is in threaded connection with the focus fixing rod and is configured to selectively abut against the shell so as to limit the position of the focus fixing rod; and when the fixed part is released from pressing the shell, at least part of the fixed focus rod can extend out of the adjusting groove from the output end. When focusing is needed, the fixing part is released from abutting against the shell, and at least part of the focus fixing rod can extend out of the adjusting groove from the output end. The end, close to the output end, of the focus fixing rod makes contact with the surface of the workpiece, and therefore the distance between the laser and the workpiece is positioned. Laser focusing positioning is simple and convenient, and the adjusting speed is high.

The application belongs to the technical field of semiconductor lithography, and discloses a mask absorption layer structure with low three-dimensional effect, which comprises a quartz substrate, a bottom anti-reflection layer, an absorption layer main body and a top anti-reflection layer. The bottom anti-reflection layer is deposited on the surface of the quartz substrate. The absorption layer main body is deposited on the side of the bottom anti-reflection layer away from the quartz substrate. The top anti-reflection layer is deposited on the side of the absorption layer main body away from the bottom anti-reflection layer. The absorption layer main body forms a patterned groove structure required for lithography in the XY plane. The absorption layer main body is provided with a partition modulation structure matched with the diffraction characteristics of the patterned groove structure in the Z-axis direction perpendicular to the XY plane, which can adjust the light field distribution of incident light and the phase of transmitted light, eliminate multiple reflections and phase distortion in the groove, reduce the adverse effects of mask three-dimensional effect, improve the lithography focusing precision and pattern size control ability, and meet the lithography application requirements of advanced process nodes.

The utility model discloses a guide rail type focusing device, and relates to the technical field of guide rail type focusing. The guide rail type focusing device comprises a transmission gear, a fixing support, an image sensor and a stepping motor. The transmission gear is in sliding connection with the fixing support, the image sensor is arranged on the fixing support, a spring is further arranged between the image sensor and the fixing support, a driving gear is arranged at the output end of the stepping motor, and the driving gear is connected with the transmission gear in a meshed mode. According to the guide rail type focusing device provided by the utility model, the image sensor is arranged on the fixed bracket, and the fixed bracket performs lifting motion so as to achieve the purpose of focusing. In addition, a guide rail mode formed by the transmission gear and the fixing support enables a guide rail inclined groove and an inclined bone position to be in surface-to-surface contact so as to achieve the purposes of stability and zero clearance, assembly tolerance is reduced, focusing precision is improved, high-speed snapshot is achieved, meanwhile, the whole image is clear and balanced, and the problem that one side of the image is clear and the other side of the image is blurred is solved.

The application relates to a terahertz radar-based focusing imaging method, device, equipment and medium. The method comprises the following steps: obtaining echo signals of a uniformly rotating large-size target based on a terahertz radar, performing distance-direction pulse compression and azimuth-direction FFT on the echo signals to obtain a two-dimensional RD imaging result, estimating the rotation speed and longitudinal distance center offset of the target according to the spatial distribution law of the PSF inclination of each defocused point in the two-dimensional RD imaging result, constructing a final phase compensation function according to the finally estimated rotation speed and longitudinal distance center offset, performing second-order spatially-varying phase compensation and azimuth-direction FFT on a one-dimensional distance image after Keystone transformation according to the final phase compensation function, and obtaining a finally focused RD image. The method can reduce the calculation search amount of terahertz radar RD focusing imaging and improve the focusing accuracy.

The invention discloses an automatic focusing method and device, and belongs to the field of high-precision measurement. The method comprises the steps of setting motion axis parameters, collecting a real-time image, calculating the blurring width of the image and calculating the focusing position. According to the method, the fuzzy edge width is directly calculated, the minimum fuzzy edge width is obtained, and the focusing precision is high. And the focusing height is locally solved, so that multi-height characteristic measurement is more accurate and is not easily influenced by noise. The repeatability is good, and the focusing height with stable image features can be obtained under the condition that the motion axis is not changed.

The invention discloses a camera module and electronic equipment, and belongs to the technical field of camera shooting. The electronic equipment comprises a camera module, wherein the camera module comprises a decorative ring; the lens is arranged on the decorative ring, an emitting part and a receiving part of the laser focusing element are arranged towards the lens, and the laser focusing element and the lens are arranged at an interval in the thickness direction of the lens; the blocking piece is arranged on the laser focusing element, at least part of the blocking piece is located between the laser focusing element and the lens, and at least part of the blocking piece is located between the optical axis of the emitting part and the optical axis of the receiving part so as to block the detection light emitted by the emitting part from being transmitted to the receiving part through the space between the laser focusing element and the lens.

The application belongs to the technical field of water turbine processing, and particularly relates to a positioning method of a robot shovel-grinding water turbine movable guide vane tooling. The positioning method comprises the following steps: installing a short shaft end positioning mechanism; installing a long shaft end positioning mechanism to position the Y-axis direction of a guide vane coordinate axis; hoisting the guide vane to make the short shaft end face of the guide vane adhere to the positioning end face of the short shaft end positioning mechanism tooling, and first perform axial coarse adjustment, then perform axial fine adjustment after the axial coarse adjustment is completed, and position the X-axis direction of the guide vane coordinate axis; position the Z-axis direction of the guide vane coordinate axis; install two jacks to support the left and right ends of a guide vane blade body profile, and adjust the guide vane to limit the rotation of the X-axis of the guide vane coordinate axis. The method can reduce the adhesion degree of the guide vane and the tooling from the level of 1mm-10mm to 0.1mm-1mm, and effectively reduces the number of manual teaching of the robot cutter track through the limiting of the tooling, and improves the working efficiency of the automatic shovel-grinding of the guide vane.

The utility model relates to the technical field of solar light and heat power generation discloses a solar heliostat. The solar heliostat includes: first sub mirror, the distribution of at least two second sub mirrors around the first sub mirror week side, support frame, stand and tracking mechanism, the axis of stand is perpendicular to ground, support frame is located at the top of stand, tracking mechanism is used for driving support frame action, first sub mirror and second sub mirror are located at the side of support frame away from the stand, first sub mirror and support frame fixed connection, every second sub mirror is connected with support frame rotation to the edge part of first sub mirror, the rotation axis of second sub mirror is perpendicular to the arrangement direction of itself and first sub mirror, and is parallel to the mirror surface of first sub mirror, and the part of second sub mirror away from first sub mirror is equipped with support part, and support frame is connected with support part through an adjusting part. The solar heliostat can realize the fast adjustment focal length, and the positioning accuracy is higher, and it is favorable for improving the focusing accuracy of heliostat.

The invention discloses a measuring microscope rapid automatic focusing method based on an ISP chip, and the method comprises the steps: obtaining an image from a microscope camera, inputting the image into the ISP chip, carrying out the blocking processing of the image, calculating the definition value of each block, and aiming at the definition value of each block, combining with the center bias correction and the compensation processing of the adjacent blocks, thereby achieving the rapid automatic focusing of a measuring microscope. And obtaining a corrected definition value, selecting a block area with the maximum definition value, gradually adjusting the position of a microscope lens by using a hill climbing method, dynamically adjusting the focal length, and finally determining an optimal focusing point and completing automatic focusing. According to the method, the ISP chip is used for hardware acceleration processing, the focusing speed and precision are greatly improved, and the method is suitable for complex measurement environments under different illumination conditions and has wide application prospects.

The application discloses a focusing control method and related device, applied to an electronic device, the method comprising: when opening a camera, acquiring a phase difference source image and an initial voltage value corresponding to an initial focusing position; determining a target focusing position; acquiring a target phase difference of the target focusing position according to the phase difference source image; acquiring a target fitting broken line, the target fitting broken line comprising a segment fitting straight line group, and the horizontal coordinate of the target fitting broken line being a voltage value and the vertical coordinate being a phase difference, the segment fitting straight line comprising a‑1 segment points; determining a target fitting line from the target fitting broken line according to the initial voltage value and the a‑1 segment points, the target fitting line being at least one segment fitting straight line in the a segment fitting straight lines; determining a target voltage adjustment amount according to the target fitting line, the target phase difference and the initial voltage value; and adjusting an adjustable focusing lens according to the target voltage adjustment amount. The embodiment of the application can improve the focusing accuracy of the adjustable focusing lens.

The utility model relates to the technical field of measuring devices, in particular to a rapid focusing measurement flash tester, which comprises a base, a telecentric parallel light source component arranged on the base, a stand column arranged on the base, an upper bearing fixing seat arranged at the upper end of the stand column, a lower bearing fixing seat arranged at the lower end of the stand column, and a screw rod arranged between the upper bearing fixing seat and the lower bearing fixing seat. A glass objective table fixing seat is arranged over the telecentric parallel light source assembly, a glass objective table is arranged on the glass objective table fixing seat, a nut seat is arranged on the glass objective table fixing seat, the nut seat is in threaded fit with the lead screw through a threaded hole, a sliding block is arranged on the glass objective table fixing seat, and the sliding block is in threaded fit with the lead screw through a threaded hole. The sliding block is in sliding fit with a sliding rail arranged on the stand column, a grating reading head is arranged on the glass objective table fixing base and is in sliding fit with a grating ruler arranged on the stand column, a support is arranged on the stand column, a lens is arranged on the support, a surface light source assembly is arranged below the lens, and a camera is arranged above the lens.

The invention relates to exposure equipment, which comprises a target light projection module, a to-be-exposed workpiece, a focusing light processing module and a focusing module, and is characterized in that the target light projection module is used for forming a target focusing light beam and a target exposure light beam on the to-be-exposed workpiece; the focusing module comprises a one-dimensional second linear image sensor for receiving the first target projection beam to form a first focusing pattern and for receiving the second target projection beam to form a second focusing pattern; the target projection light beam is obtained by processing a target focusing light beam reflected by the to-be-exposed workpiece based on the focusing module, and the focus position of the target focusing light beam on the to-be-exposed workpiece is determined based on the light and shade contrast of the first focusing pattern and the second focusing pattern. The to-be-exposed workpiece is subjected to exposure processing at the focus position based on the target exposure light beam. The one-dimensional linear image sensor only needs to process one-dimensional data, and the algorithm and the processing process are relatively simple, so that the overall focusing speed of the exposure equipment is improved.

The invention discloses equipment for improving or removing a traditional painting and calligraphy ink seal, which comprises a laser equipment main body, one side of the laser equipment main body is provided with a corrugated pipe, one end of the corrugated pipe is provided with a laser head, one end of the laser head is provided with an emission head, the laser equipment main body comprises a box body, the top of the box body is fixedly connected with a handle, and the top of the box body is fixedly connected with the handle. A control panel is fixedly installed on one side of the box body, and a controller electrically connected with the control panel is fixedly installed on the inner wall of the box body. The device has the advantage of high efficiency, and solves the problems that in the using process of existing equipment for improving or removing painting and calligraphy ink seals, continuous and efficient operation is not convenient, frequent interruption and resetting possibly cause inconsistent treatment effects each time, the final repairing quality is affected, and the repairing efficiency is affected. And operators need to spend more time and energy to adjust the equipment and process each work, so that the labor cost is increased.

The utility model discloses a camera module and an electronic device, and the camera module is used for improving the imaging quality. The lens assembly comprises a lens base, a lens, a guide part and a driving part, the guide part is connected with the mounting base and extends in the optical axis direction of the lens, the lens base and the guide part are slidably connected in the optical axis direction of the lens, the lens is mounted on the lens base, and the driving part is arranged on the mounting base, connected with the lens base and used for driving the lens base to slide; the protection assembly comprises a supporting seat, a light-transmitting part and an elastic part, the supporting seat and the lens seat are in sliding connection in the optical axis direction of the lens, the supporting seat is provided with a light-transmitting hole and a mounting groove, the light-transmitting hole penetrates through the supporting seat in the optical axis direction of the lens, the lens is contained in the light-transmitting hole, and the mounting groove is formed in the side, away from the lens seat, of the supporting seat and communicates with the light-transmitting hole; the light-transmitting part is mounted in the mounting groove, the guide part is sleeved with the elastic part, and the two ends of the elastic part abut against the lens base and the supporting base respectively; and the heating piece is arranged in the mounting groove, is positioned between the lens and the light-transmitting piece and is used for heating the light-transmitting piece.

The invention relates to a system for detecting a focal plane of an infinite-distance microscopic system. The system comprises an objective lens, a spectroscope, a tube lens, an image acquisition module and an image processing module. The objective lens collects light reflected by an object and converts the light into parallel light, and the spectroscope separates the parallel light into two parts which are respectively transmitted to the tube lens and the image acquisition module. The first tube lens receives part of light and focuses the light on an image focal plane, the second tube lens in the image acquisition module receives the other part of light and focuses the light on the digital camera photosensitive chip, and the digital camera photosensitive chip is obliquely mounted to ensure light focusing of a specific field of view. And the image processing module processes the digital image through partitions and analyzes the definition curve graph, and calculates an object plane defocusing amount to determine an optimal focal plane position.

The invention discloses a simple area array detector focus fixing method for light beam scanning based on a glass parallel plate, and belongs to the field of optical measuring instruments. The implementation method comprises the steps that a glass parallel plate is placed in front of an objective lens, the parallel plate is perpendicular to a light beam, thin parallel incident light passes through the glass parallel plate and then is focused on a detector through the objective lens to form a light spot, the detector collects a light spot image, and then the position of the light spot mass center is obtained through a mass center calculation algorithm; rotating the glass parallel plate, acquiring light spot images of the glass parallel plate at different rotation angles, and judging whether the detector is in a pre-focus state or a post-focus state at the moment; obtaining a defocusing amount according to the position of the mass center of the light spot; precise focus fixing adjustment is completed by increasing or decreasing gaskets at the installation position of the detector, the increase or decrease of the gaskets is determined or the gaskets are properly ground according to the fact that the detector is judged to be in a pre-focus state or a post-focus state and the calculated defocusing amount, and simple and convenient focus fixing of the detector is completed. The centroid positioning precision of the invention can reach the precision of one percent pixel.

The invention relates to an industrial camera automatic focusing method and device based on machine vision, and the method comprises the steps: 1) carrying out a focusing experiment, collecting a focusing value and corresponding position data of each experiment to obtain a plurality of training models, clustering the training models corresponding to the positive focal values, and setting the clustered training models as prediction models; 2) controlling a motor to drive an industrial camera, collecting multiple frames of images, generating relation data of a focusing value and a position to form a sample function, and calculating related characteristics; 3) substituting the generated focusing value into the training model, comparing the related characteristics of the sample function and the training function, and generating position data corresponding to the last frame by using the closest training function; and 4) combining the position data corresponding to the last frame, the prediction model and the system hardware parameters, calculating the working time of the motor, and driving the industrial camera to complete automatic focusing. Compared with the prior art, the phenomenon of local focusing maximum value caused by environmental factors can be effectively overcome, and rapid and accurate automatic focusing can be realized at any position in an effective stroke.

This invention discloses an autofocus method, apparatus, electronic device, and storage medium, belonging to the field of autofocus technology. The autofocus method includes: adjusting the focal length within a first focusing range according to a first preset step size, acquiring a first image captured by the camera at each focal length, and determining an effective focusing area and a second focusing range based on the first image; adjusting the focal length within a second focusing range according to a second preset step size, acquiring a second image captured by the camera at each focal length, and determining the optimal focusing position based on the sharpness evaluation value of the effective focusing area in the second image; wherein the first preset step size is greater than the second preset step size. This invention performs focusing in two stages: the first stage uses a large step size to filter the effective focusing area and narrow the focusing range, and the second stage uses a small step size for focusing and uses fewer but more effective areas for focusing, thus achieving higher operating efficiency.

The invention discloses a focusing method, device and equipment of a scanning electron microscope, a medium and a product, and is applied to the field of semiconductor manufacturing. The method comprises the steps of obtaining a first image and image definition based on a plurality of first focal lengths, and predicting a first target focal length with the highest image definition; then, determining a plurality of second focal lengths based on the first target focal length, respectively obtaining a second image and image definition, and carrying out secondary prediction to obtain a second target focal length with the highest image definition; therefore, high-precision automatic focusing is realized. According to the scheme, high-precision real-time focusing can be realized through two times of focal length prediction in one focusing process, and particularly, under the condition of high magnification, the focusing precision can be improved while real-time focusing is ensured. For a scanning electron microscope, the performance can be improved; for scanning electron beam equipment, the throughput of the equipment can be greatly improved, and the performance competitiveness of the equipment is improved.

The present invention relates to a focusing module, an automatic focusing microscopic imaging system and a method. The focusing module of the present invention comprises: an optical path difference element, which receives and processes a total focusing beam to obtain at least three focusing beams with optical path differences; the optical path difference element is any one of an X-ray prism, a trapezoidal prism, a triangular prism, and a hexagonal prism; and a focusing sensor group, which is used to receive the focusing beams respectively. The focusing module of the present invention has the advantages of high focusing accuracy and compact structure.