Fourier plane filter detection device, detection system and detection method

Abstract

This disclosure provides a Fourier surface filter detection device, detection system, and detection method. The Fourier surface filter detection device includes a mounting frame and a detection unit. The detection unit is mounted on the mounting frame, which is used to adjust the three-dimensional spatial position of the detection unit. The detection unit includes a housing, a light-shielding component, and a driving component. The housing has a through-hole for a light beam to enter the housing and form a Fourier optical surface within it. The light-shielding component is located inside the housing and is used to block the through-hole to adjust different light-shielding areas. The driving component is located inside the housing and is used to drive the light-shielding component closer to or further away from the through-hole to adjust different light-shielding areas. The Fourier surface filter detection device of this disclosure can improve detection efficiency.

Description

Technical Field

[0001] This disclosure relates to the field of optical detection technology, specifically to a Fourier surface filter detection device and detection method. Background Technology

[0002] Optical detection technology is an important method for feature target detection. During the detection process, the signal light is often accompanied by background scattering or diffraction noise from the object being measured, leading to a decrease in the contrast of the feature target signal and affecting the accuracy of the feature target image. Fourier optical surface filtering is an effective way to reduce interference signals. By blocking noisy areas, the signal-to-noise ratio of the final acquired signal can be effectively improved. However, the distribution of noisy areas is quite complex. If a fixed device is used for blocking, it is impossible to achieve precise matching with the noisy area, resulting in limited improvement in signal accuracy. On the other hand, if multiple blocking devices are combined, it is necessary to constantly change the blocking devices, resulting in low detection efficiency. Summary of the Invention

[0003] In view of this, the present disclosure aims to provide a Fourier surface filter detection device that can improve detection efficiency.

[0004] The first aspect of this disclosure provides a Fourier surface filter detection device, comprising: a mounting frame and a detection unit, wherein the detection unit is disposed on the mounting frame, and the mounting frame is used to adjust the three-dimensional spatial position of the detection unit; the detection unit includes a housing, a light-shielding component, and a driving component, wherein the housing is provided with a light-transmitting hole through the housing, the light-transmitting hole allowing a light beam to enter the housing to form a Fourier optical surface within the housing, the light-shielding component is disposed within the housing, the light-shielding component is used to block the light-transmitting hole to adjust different light-shielding areas, and the driving component is disposed within the housing, the driving component is used to drive the light-shielding component closer to or further away from the light-transmitting hole to adjust different light-shielding areas.

[0005] This configuration, with its mounting bracket for three-dimensional spatial positioning adjustment, ensures that the light-transmitting aperture of the detection unit is precisely aligned with the optical axis of the incident beam, establishing an accurate spatial reference for subsequent filtering. The detection unit integrates a movable light-shielding component driven by a drive assembly, allowing the shading area to be flexibly and continuously adjusted according to the actual noise distribution on the Fourier optical surface. Compared to the replacement of the light-shielding mechanism in related technologies, this approach improves the adaptability of filtering and the detection of characteristic targets, such as the signal-to-noise ratio detection of defect signals, without sacrificing detection efficiency.

[0006] In some embodiments, the light-shielding assembly includes a first guide rail, a second guide rail, a first light-shielding component, and a second light-shielding component. The first guide rail and the second guide rail are respectively disposed within the housing and are symmetrically arranged on both sides of the light-transmitting hole. The first light-shielding component and the second light-shielding component are respectively connected to the first guide rail and the second light-shielding component. Both the first light-shielding component and the second light-shielding component include a plurality of light-shielding plates. The plurality of light-shielding plates are arranged at intervals in the height direction of the housing, and the light-shielding plates in the first light-shielding component and the light-shielding plates in the second light-shielding component can approach or move away from each other.

[0007] This configuration, by specifying the light-shielding components as a first guide rail and a second guide rail symmetrically arranged on both sides of the light-transmitting aperture, and a first light-shielding component and a second light-shielding component respectively mounted on them and containing multiple spaced light-shielding plates, decomposes the requirement for continuous shading over a large area into multiple discrete light-shielding units that can move independently radially. This allows the system to combine complex and varied shading patterns by controlling the movement of each light-shielding plate, providing a fundamental mechanical structural possibility for achieving precise matching with noise regions of arbitrary shapes on the Fourier optical surface.

[0008] In some embodiments, the plurality of light-shielding plates in the first light-shielding component and the second light-shielding component are divided into multiple groups of light-shielding plates. The multiple groups of light-shielding plates in the first light-shielding component are symmetrically arranged in the thickness direction of the first guide rail with the Fourier optical surface as the plane of symmetry. The multiple groups of light-shielding plates in the second light-shielding component are symmetrically arranged in the thickness direction of the second guide rail with the Fourier optical surface as the plane of symmetry. In the same direction, the groups of light-shielding plates in the first light-shielding component and the groups of light-shielding plates in the second light-shielding component are symmetrically distributed on both sides of the light-transmitting hole.

[0009] This configuration further divides the multiple light-shielding plates into groups, symmetrically arranged along the thickness direction of their respective guide rails with the Fourier optical surface as the plane of symmetry. Simultaneously, it ensures that the groups of light-shielding plates in the same direction on both sides of the guide rails are also symmetrically distributed on both sides of the light-passing aperture. This symmetrical grouping layout fully considers and matches the symmetrical characteristics of the spectral distribution after the optical Fourier transform, enabling symmetrical filtering operations. This helps to filter out symmetrically distributed noise components more accurately and systematically, improving the accuracy of filtering and the systematic nature of control.

[0010] In some embodiments, each group of light-shielding plates has a plurality of light-shielding plates of the same number, and the plurality of light-shielding plates are arranged at intervals in the height direction of the housing.

[0011] This configuration limits each group of light-shielding plates to the same number of light-shielding plates. This ensures that, in a symmetrical arrangement, the number of light-shielding units at each symmetrical position is equal, providing a basis for performing symmetrical filtering operations, simplifying the complexity of the symmetrical control algorithm, and guaranteeing the consistency of the filtering effect on both sides of the symmetry axis.

[0012] In some embodiments, both the first guide rail and the second guide rail have multiple guide grooves that extend radially along the light-transmitting hole, and the multiple guide grooves are arranged at intervals in the height direction of the housing.

[0013] This configuration involves creating multiple guide grooves on the first and second guide rails that extend radially along the light-transmitting holes and are spaced apart in the height direction. These guide grooves provide a precisely defined moving track for each light-shielding plate, ensuring that all light-shielding plates move strictly in a radial straight line during movement, preventing deflection or jamming. This is a key mechanical structure guarantee for achieving precise and reliable position control of the light-shielding plates.

[0014] In some embodiments, the first guide rail has a first side and a second side in its thickness direction. Multiple guide grooves are formed on both the first and second sides. These guide grooves are staggered in the height direction of the housing. The guide grooves on the first side are spaced apart by a distance D1, and the staggered distance between the guide grooves on the first and second sides is D2, where D1 = 2D2. The second guide rail has a third side and a fourth side in its thickness direction. Multiple guide grooves are formed on both the third and fourth sides. These guide grooves are staggered in the height direction of the housing. The guide grooves on the third side are spaced apart by a distance D3, and the staggered distance between the guide grooves on the third and fourth sides is D4, where D3 = 2D4, and D3 = D1.

[0015] This configuration involves creating guide grooves on both sides of the thickness of a single guide rail, with the grooves on both sides staggered in the height direction. Simultaneously, the spacing D1 between the guide grooves on the same side is twice the staggered distance D2 (i.e., D1 = 2D2). This allows the light-shielding plates extending from both sides of the guide rail to be staggered in the height direction; in other words, the light-shielding plates on both sides of the guide rail can form a periodic arrangement, thus improving the matching degree with the periodic arrangement of diffraction orders on the Fourier optical surface. Furthermore, when using light-shielding plates with a width greater than D2, the light-shielding plates on both sides can overlap and cover each other during movement. This allows the effective blocking position of the entire light-shielding assembly in the height direction to be adjusted in steps of D2, improving the system's ability to fine-tune the boundaries of noise regions and the precision of filtering.

[0016] In some embodiments, the width of the light-shielding plate is D5, and D5 > D2 = D4, and / or, the distance between the light-shielding plate located on the first side and the light-shielding plate located on the second side in the thickness direction of the first guide rail is less than or equal to 1 mm, and / or, the distance between the light-shielding plate located on the third side and the light-shielding plate located on the fourth side in the thickness direction of the second guide rail is less than or equal to 1 mm.

[0017] This configuration limits the width D5 of the light-shielding plate to be greater than the staggered distances D2 and D4 of the guide grooves, and limits the spacing between the light-shielding plates on the two sides of the same guide rail in their thickness direction to be less than or equal to 1 mm. The former ensures that the light-shielding plates extending from both sides of the guide rail have sufficient width to overlap during movement, thereby achieving continuous blocking coverage and avoiding gaps that allow light leakage, forming a tight blockage. The latter controls the non-working gap between the two light-shielding plates to a very small range, minimizing unnecessary light leakage caused by structural gaps. The combination of these two features ensures that the staggered light-shielding structure can achieve a high-precision, seamless, continuous area blocking effect.

[0018] In some embodiments, the side of the light-shielding plate facing the Fourier optical surface is a plane.

[0019] This configuration ensures that the side of the light-shielding plate facing the Fourier optical surface is flat. This allows the edge of the light-shielding plate to form a clear and sharp geometric boundary when facing the complex light field on the Fourier optical surface. Compared to beveled or rounded edges, flat edges more effectively cut off light, reducing stray light caused by edge diffraction or scattering, and avoiding the introduction of new noise during filtering. This ensures the effectiveness of the blocking operation and further improves the signal-to-noise ratio of the final signal.

[0020] In some embodiments, the maximum travel distance of the light-shielding plate is L1, and L1 > M, where M is the aperture of the light-transmitting hole, and / or, the distance between the light-shielding plate on the first guide rail and the light-shielding plate on the second guide rail in the radial direction of the light-transmitting hole is L2, and M < L1 < L2, and / or, the distance between the first guide rail and the second guide rail in the radial direction of the light-transmitting hole is L3, and L3 > M.

[0021] This configuration ensures that the maximum travel L1 of the light-shielding plate is greater than the aperture M of the light-transmitting hole, guaranteeing that each single-sided light-shielding plate has sufficient range of motion to move from a position completely away from the light path to a position sufficient to completely cover the light-transmitting hole, thus providing travel assurance for achieving full aperture blocking. Simultaneously, the initial radial spacing L2 between the light-shielding plates on both guide rails and the light-transmitting hole is greater than L1, providing ample space for the two light-shielding plates to move towards each other until they contact or overlap. This prevents collisions or mechanical interference during movement due to insufficient travel or excessively small initial spacing, ensuring the feasibility and safety of the mechanism's movement.

[0022] In some embodiments, the number of light-shielding plates is N, and N≥4M / D1.

[0023] This configuration ensures that a sufficient number of light-blocking plates can be arranged radially within the aperture M. Since the light-blocking plates are symmetrical on both sides and their center-to-center distance is D1 / 2, the sheer number guarantees that the system has enough spatial sampling points, enabling sufficiently fine discretization control of the aperture. This is the foundation for the system's ability to approximate the target occlusion pattern at high resolution. Furthermore, when all N light-blocking plates are extended, they can completely block the light-transmitting area, avoiding or reducing the risk of light leakage.

[0024] In some embodiments, the Fourier surface filter detection device further includes a support frame disposed within the housing. The drive assembly includes a first drive component and a second drive component, which are respectively disposed on the support frame. The first drive component is connected to the first light-shielding component to drive the first light-shielding component closer to or away from the light-transmitting hole. The second drive component is connected to the second light-shielding component to drive the second light-shielding component closer to or away from the light-transmitting hole.

[0025] This configuration, with the addition of a support frame within the housing, specifies the drive assembly as a first drive component and a second drive component respectively mounted on the support frame, connecting and driving the first and second light-shielding components. The support frame provides a stable mounting base for the drive components, ensuring the stability of the driving force transmission. The independent drive components allow the light-shielding components on both sides to be controlled separately, thereby forming an asymmetrical shading pattern, enhancing the filtering capability for asymmetrical noise distribution, and improving the system's applicability and flexibility.

[0026] In some embodiments, both the first driving component and the second driving component include a driver, a driving rod, and a connecting rod. The driver is mounted on the support frame, and the output shaft of the driver is connected to the driving rod. The connecting rod is sleeved on the driving rod, and the driving rod can drive the connecting rod to move radially along the light-transmitting hole. The end of the connecting rod away from the driving rod is connected to the light-shielding plate.

[0027] This configuration concretizes each driving component into a transmission mechanism consisting of a driver, a drive rod, and a connecting rod. The driver provides rotational power, the drive rod converts the rotational motion into linear motion, and ultimately pushes the light-shielding plate through the connecting rod. In this way, the output of the driver is accurately and directly transmitted to the light-shielding plate, forming a simple, reliable, easy-to-control, and compact linear drive structure.

[0028] In some embodiments, the number of the first driving components is the same as the number of light-shielding plates in the light-shielding plate group of the first light-shielding component. When there are multiple light-shielding groups in the first light-shielding component, the connecting rods in the multiple first driving components are arranged alternately at intervals in the thickness direction of the housing. The number of the second driving components is the same as the number of light-shielding plates in the light-shielding plate group of the second light-shielding component. When there are multiple light-shielding groups in the second light-shielding component, the connecting rods in the multiple second driving components are arranged alternately at intervals in the thickness direction of the housing.

[0029] This configuration alters the spatial layout of the drive components by arranging the connecting rods of multiple drive components corresponding to multiple light-shielding plate groups in a staggered manner along the thickness direction of the housing. Compared to the long radial space required for linear arrangement in related technologies, this disclosure utilizes the space in the thickness direction, achieving mutual avoidance through the staggered arrangement of connecting rods of different lengths. This allows multiple drive components and their transmission mechanisms to be compactly integrated within a limited radial dimension. By slightly increasing the dimension in the thickness direction, independent control of one drive per group is achieved. While ensuring that each light-shielding group can be driven independently and precisely, the space utilization of the system is optimized, resulting in an extremely compact overall structure. This solves the problem of excessively large radial dimensions in multi-drive unit layouts, providing crucial support for the miniaturization and integration of the system.

[0030] In some embodiments, the Fourier surface filter detection device further includes a guide assembly disposed within the housing, and the guide assembly and the drive assembly are staggered in the height direction of the housing. The guide assembly includes a guide rod and a guide bearing, the guide bearing is sleeved on the guide rod and is movable on the guide rod, and the guide bearing is connected to the connecting rod.

[0031] This configuration adds a guide assembly within the housing, staggered in the height direction from the drive assembly. The guide assembly includes a guide rod and a movable guide bearing fitted onto it, with the guide bearing connected to the connecting rod. The guide assembly provides the connecting rod with a second support point away from the drive end, forming a stable two-point support together with the drive end. This effectively resists overturning moments or lateral shifts caused by uneven force during the movement of the light-shielding plate, ensuring that the light-shielding plate always moves smoothly along the radial straight line specified by the guide groove, maintaining long-term motion accuracy.

[0032] In some embodiments, the Fourier surface filter detection device further includes a limiting component, which includes a limiting switch and a sensor. The sensor is installed at one end of the connecting rod adjacent to the guide bearing, and the limiting switch is located inside the housing and corresponds to the sensor.

[0033] This configuration, with the addition of a limit assembly including a limit switch and a sensor, with the sensor mounted on the connecting rod near the guide bearing and corresponding to the limit switch on the housing, provides mechanical limit position protection for the movement of the light-shielding plate. When the light-shielding plate moves to its limit position, the sensor triggers the limit switch, immediately cutting off the drive or sending a signal to prevent the light-shielding plate from overtraveling due to control errors or malfunctions, thus preventing collisions with adjacent components or the housing. This protects the mechanical structure from damage and improves the safety and reliability of the system.

[0034] The second aspect of this disclosure discloses a Fourier leaf filter detection system, comprising: The receiving optical module is used to receive the optical features after Fourier surface filtering; The monitoring optical module is used to monitor optical features on the Fourier transform surface; A detection device, wherein the detection device is the Fourier surface filter as described in any one of the first aspects.

[0035] This configuration, by integrating a receiving optical module, a monitoring optical module, and a precision adjustable filtering detection device as described in the first aspect, constructs a fully functional intelligent detection system with real-time feedback. The monitoring optical module can observe the light field distribution on the Fourier surface in real time, providing direct image or signal evidence for judging noise areas and evaluating filtering effects. The receiving optical module is specifically used to acquire the final optical signal after filtering by the detection device. These two modules work in conjunction with the programmable precision filtering detection device, enabling the system to dynamically and precisely control the light-shielding components in the detection device based on feedback from the monitoring module, achieving optimal matching with the noise area. This not only inherits the advantages of the device in the first aspect—flexible and precise tuning of the filtering area—but further achieves real-time optimization and self-adaptation of the filtering process through a closed loop of monitoring-adjustment-reception, thereby raising the signal-to-noise ratio and detection accuracy of the defect signal to a new level.

[0036] The third aspect of this disclosure provides a Fourier surface filter detection method, comprising the following steps: adjusting the position of the housing by means of a mounting bracket so that the axis of the light-transmitting hole on the housing coincides with the optical axis of the light beam entering the housing; determining whether the first central plane formed by the light-shielding plate on the first side and the light-shielding plate on the second side, and the second central plane formed by the light-shielding plate on the third side and the light-shielding plate on the fourth side coincide with the Fourier optical surface; if the three coincide, initializing the driving component to initialize the position of the light-shielding component within the housing; determining whether the preset moving distance of each light-shielding plate meets the preset conditions; if not, resetting the preset moving distance of each light-shielding plate; if meeting the conditions, controlling each light-shielding plate to move to the target position.

[0037] With this setup, the detection method first adjusts the housing position using the mounting bracket to ensure the light-transmitting aperture axis coincides with the beam optical axis, establishing an accurate optical reference for the entire filtering process. Next, it initializes the system by determining whether the center plane of the light-shielding plate assembly coincides with the Fourier optical plane, establishing a repeatable mechanical zero position that is strictly aligned with the theoretical optical plane for the movement of all light-shielding plates. Finally, before controlling the movement of the light-shielding plates, a safety check is performed on their preset movement distance. This process combines precise mechanical adjustments with safe logical judgments, ensuring that each filtering operation is safely initiated under the premise of accurate reference and known position, thus guaranteeing the accuracy and repeatability of the filtering effect and the safety of the equipment itself from the operational process perspective.

[0038] In some embodiments, determining whether the preset movement distance of each light-shielding plate meets the preset conditions includes: determining whether the preset movement distance of a single-sided light-shielding plate exceeds its maximum travel, and / or determining whether the sum of the preset movement distances of two light-shielding plates arranged in pairs exceeds the maximum travel of the combination of the two.

[0039] This configuration specifies the preset conditions as whether the preset movement distance of a single-sided light-shielding plate exceeds its maximum stroke, and / or whether the sum of the preset movement distances of two paired light-shielding plates exceeds the maximum stroke of their combination. This constitutes a dual safety verification logic. The former prevents a single light-shielding plate from colliding with the mechanical limit switch due to incorrect instructions, while the latter prevents a pair of light-shielding plates moving in opposite directions from colliding midway due to incorrect instructions. The software limit check performed before movement execution complements the hardware limit components, effectively preventing mechanical interference and damage caused by incorrect parameter settings or calculation errors, thus improving the safety and reliability of the system during automated operation. Attached Figure Description

[0040] Figure 1 The diagram shown is a structural schematic of the Fourier surface filter detection device according to an embodiment of this disclosure.

[0041] Figure 2 The diagram shown is a structural schematic of the mounting bracket according to an embodiment of this disclosure.

[0042] Figure 3 The image shown is a front view of the detection unit according to an embodiment of this disclosure, and includes a housing.

[0043] Figure 4 The image shown is a cross-sectional view of the detection unit according to an embodiment of this disclosure.

[0044] Figure 5 The diagram shown is a schematic representation of the detection unit according to an embodiment of this disclosure, excluding the housing.

[0045] Figure 6 The diagram shown is a structural schematic of the driving component according to an embodiment of this disclosure.

[0046] Figure 7 The diagram shown is a structural schematic of the first light-shielding component according to an embodiment of the present disclosure, and includes a first driving component.

[0047] Figure 8 The image shown is a front view of the first light-shielding component according to an embodiment of this disclosure.

[0048] Figure 9 The image shown is a top view of the first light-shielding component according to an embodiment of this disclosure.

[0049] Figure 10 The diagram shown is a structural schematic of the limiting component according to an embodiment of this disclosure.

[0050] Figure 11 The diagram shown is a structural schematic of the guide component according to an embodiment of this disclosure.

[0051] Figure 12 The diagram shown is a schematic flowchart of the Fourier leaf surface filtering detection method according to an embodiment of this disclosure.

[0052] Figure label: Mounting bracket 100, detection unit 200, Fourier optical surface 300. Housing 1, light-transmitting hole 11, Light-shielding component 2, first guide rail 21, guide groove 211, second guide rail 22, First light-shielding component 23, light-shielding plate 231 Second light-shielding component 24, Driver component 3, First driving component 31, driver 311, driving rod 312, connecting rod 313, coupling 314. Second drive component 32 Support frame 4, Guide assembly 5, guide rod 51, guide bearing 52 Limit component 6, limit switch 61, sensor 62. Detailed Implementation

[0053] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0054] This disclosure provides a Fourier surface filtering detection device, primarily used in the field of optical defect detection. The system aims to dynamically and accurately filter specific noise distributions on the optical Fourier surface 300 to improve the signal-to-noise ratio of subsequent imaging. The detection system mainly includes a mounting frame 100 and a detection unit 200. The mounting frame 100 is used to support and adjust the position and orientation of the detection unit 200 in three-dimensional space.

[0055] See Figure 1 and Figure 2 As shown, the detection unit 200 includes a housing 1, a light-shielding assembly 2, and a driving assembly 3. The housing 1 forms the main frame of the detection unit 200 and is typically made of a rigid metal material to ensure the stability of the internal optical reference surface. A light-transmitting hole 11 is provided on the housing 1, penetrating its internal space. This light-transmitting hole 11 allows the beam to be processed to pass through axially. When the beam propagates within the housing 1, a Fourier optical surface 300 is formed at a specific axial position. The Fourier optical surface 300 is the key plane for spatial filtering. The light-shielding assembly 2 is disposed inside the housing 1 and located on both radial sides of the light-transmitting hole 11. Its function is to dynamically adjust the blocking of different areas of the beam by extending into or out of the beam path. The driving assembly 3 is also built into the housing 1 and is connected to the light-shielding assembly 2. It is used to independently drive each light-shielding component in the light-shielding assembly 2 to move along the direction close to or away from the axis of the light-transmitting hole 11, thereby achieving precise matching filtering of the complex light field distribution on the Fourier optical surface 300.

[0056] Optionally, the housing 1 is formed by a front cover, a back cover, a top cover, and a bottom cover, with an opening only at the light-transmitting hole 11. The enclosed structure can effectively isolate the external environment, preventing or reducing the risk of dust, oil, and other contaminants entering the housing 1, while also blocking the contamination of the clean external optical environment by any microparticles or gas release that may be generated by moving parts.

[0057] See Figure 2As shown, the mounting bracket 100 is the foundation for achieving precise alignment between the entire detection unit 200 and the external optical path system. The mounting bracket 100 can typically be a multi-degree-of-freedom adjustment platform, such as including translational degrees of freedom in multiple directions and rotational degrees of freedom about an axis. By adjusting the various adjustment mechanisms on the mounting bracket 100, the overall spatial position and angle of the detection unit 200 can be changed.

[0058] It should be noted that the mounting bracket 100 adjusts the detection unit 200 to ensure that the light beam incident from the outside can pass through the light-transmitting hole 11 on the housing 1 in a strictly coaxial manner, avoiding unnecessary obstruction or diffraction of the light beam at the edge of the light-transmitting hole 11.

[0059] Furthermore, through fine-tuning of the axis and angle, the physical center symmetry plane of the light-shielding component 2 is made to coincide in space with the Fourier optical surface 300 theoretically formed by the optical system.

[0060] This configuration, through the mounting bracket 100 for three-dimensional spatial position adjustment, ensures that the light-transmitting aperture 11 of the detection unit 200 can be precisely aligned with the optical axis of the incident beam, establishing an accurate spatial reference for subsequent filtering. The detection unit 200 integrates a movable light-shielding component 2 driven by the driving component 3, allowing the shielding area to be flexibly and continuously adjusted according to the actual noise distribution on the Fourier optical surface 300. Compared to the replacement light-shielding mechanism in related technologies, this approach improves the adaptability of filtering and the signal-to-noise ratio of the defect signal without sacrificing detection efficiency.

[0061] See Figure 4 and Figure 5 As shown, the light-shielding assembly 2 mainly includes a first guide rail 21, a second guide rail 22, a first light-shielding component 23, and a second light-shielding component 24. The first guide rail 21 and the second guide rail 22 are fixedly mounted parallel to each other on the inner bottom plate of the housing 1, and are symmetrically arranged on both sides of the housing with the axis of the light-transmitting hole 11 as the center of symmetry. The first light-shielding component 23 is connected to the first guide rail 21, and the second light-shielding component 24 is connected to the second guide rail 22.

[0062] This configuration, by specifying the light-shielding component 2 as a first guide rail 21 and a second guide rail 22 symmetrically arranged on both sides of the light-transmitting hole 11, and a first light-shielding component 23 and a second light-shielding component 24 respectively mounted thereon and containing multiple spaced light-shielding plates 231, decomposes the requirement for continuous shading over a large area into multiple discrete light-shielding units that can move independently radially. This allows the system to control the movement of each light-shielding plate 231 to create complex and varied shading patterns, providing a fundamental mechanical structural possibility for achieving precise matching with noise regions of arbitrary shapes on the Fourier optical surface 300.

[0063] See Figures 7 to 9As shown, both the first light-shielding component 23 and the second light-shielding component 24 include multiple independent light-shielding plates 231. The light-shielding plates 231 are arranged at certain intervals in the height direction of the housing 1, that is, at certain intervals in the vertical direction, forming two parallel arrays of light-shielding plates 231.

[0064] The light-shielding plates 231 in the first light-shielding component 23 and the light-shielding plates 231 in the second light-shielding component 24 are arranged in pairs. Each pair of light-shielding plates 231 can work together to adjust a certain radial region of the light beam from both sides. The driving component 3 provides an independent driving force for each light-shielding plate 231, so that the light-shielding plates 231 in the first light-shielding component 23 and the corresponding light-shielding plates 231 in the second light-shielding component 24 can move closer or further apart, thereby changing the width of the light-transmitting gap left between them, or even achieving complete closure or complete opening.

[0065] To achieve higher spatial filtering resolution within a limited space, the light-shielding plates 231 need to be arranged as densely as possible. This disclosure employs a two-layer distribution design. Specifically, the multiple light-shielding plates 231 in the first light-shielding component 23 and the second light-shielding component 24 are divided into multiple groups of light-shielding plates.

[0066] This configuration further divides the multiple light-shielding plates 231 into multiple groups, symmetrically arranged along the thickness direction of their respective guide rails with the Fourier optical surface 300 as the plane of symmetry. Simultaneously, it ensures that the light-shielding plate groups on both guide rails, in the same direction, are also symmetrically distributed on both sides of the light-passing aperture 11. This symmetrical grouping layout fully considers and matches the symmetrical characteristics of the spectral distribution after the optical Fourier transform, enabling symmetrical filtering operations. This helps to filter out symmetrically distributed noise components more accurately and systematically, improving the accuracy of filtering and the systematic nature of control.

[0067] See Figure 7 As shown, taking the first light-shielding component 23 as an example, its multiple sets of light-shielding plates are symmetrically arranged along the thickness direction of the first guide rail 21 with the Fourier optical surface 300 as the plane of symmetry. Thus, light-shielding plates 231 are arranged on both the front and rear sides of the Fourier optical surface 300. The second light-shielding component 24 adopts the same symmetrical arrangement. Furthermore, in the same direction, the light-shielding plate sets of the first light-shielding component 23 and the second light-shielding component 24 are symmetrically distributed about the light-transmitting hole 11.

[0068] Each group of light-shielding plates has the same number of light-shielding plates 231, which are staggered along the height direction of the housing 1.

[0069] This configuration limits each group of light-shielding plates to have the same number of light-shielding plates 231. This ensures that, in the case of a symmetrical arrangement, the number of light-shielding units at each symmetrical position is equal, providing a basis for performing symmetrical filtering operations, simplifying the complexity of the symmetrical control algorithm, and guaranteeing the consistency of the filtering effect on both sides of the symmetry axis.

[0070] See Figure 8 As shown, the first guide rail 21 has a first side facing the front of the Fourier optical surface 300 and a second side facing the rear of the Fourier optical surface 300 in its thickness direction. Multiple guide grooves 211 extending radially along the light-transmitting hole 11 are formed on both sides. The multiple guide grooves 211 are arranged at intervals in the height direction of the housing 1.

[0071] With this configuration, multiple guide grooves 211 are formed on the first and second guide rails 22, extending radially along the light-transmitting holes 11 and spaced apart in the height direction. The guide grooves 211 provide a precisely defined moving track for each light-shielding plate 231, ensuring that all light-shielding plates 231 can move strictly in a radial straight line during movement, preventing deflection or jamming. This is a key mechanical structure guarantee for achieving precise and reliable position control of the light-shielding plates 231.

[0072] For example, the guide grooves 211 on the first and second sides are staggered. That is, the position of the Nth guide groove 211 on the first side in the height direction corresponds to the position between the Nth and (N+1)th guide grooves 211 on the second side. Assume that the interval between adjacent guide grooves 211 on the first side is D1, and the stagger distance between corresponding guide grooves 211 on the first and second sides is D2, and D1 = 2D2.

[0073] This configuration involves creating guide grooves 211 on both sides of the thickness of a single guide rail, with the guide grooves 211 on both sides staggered in the height direction. Simultaneously, the spacing D1 between the guide grooves 211 on the same side is twice the staggered spacing D2 (i.e., D1 = 2D2). This allows the light-shielding plates 231 extending from both sides of the guide rail to be staggered in the height direction. In other words, the light-shielding plates 231 on both sides of the guide rail can form a periodic arrangement, thus improving the matching degree with the periodic arrangement of diffraction orders on the Fourier optical surface 300. Furthermore, when using a light-shielding plate 231 with a width greater than D2, the light-shielding plates 231 on both sides can overlap and cover each other during movement. This allows the effective blocking position of the entire light-shielding assembly 2 in the height direction to be adjusted in steps of D2, improving the system's ability to fine-tune the boundary of the noise region and the precision of filtering.

[0074] The second guide rail 22 adopts the same structure. The guide grooves 211 on its third and fourth sides are also arranged in the same pattern, and their interval distance D3 is equal to D1, and the stagger distance D4 is equal to D2.

[0075] For example, the width D5 of the light-shielding plate 231 is greater than the stagger distance D2 of the guide grooves 211. This ensures that when the light-shielding plate 231 is embedded in the corresponding guide groove 211, its large plate body can effectively cover the gaps between adjacent staggered guide grooves 211, preventing light beams from leaking from these structural gaps and ensuring that only the light-transmitting area precisely controlled by the blade of the light-shielding plate 231 can transmit light.

[0076] To further improve filtering accuracy, the light-shielding plate 231 located on the first side and the light-shielding plate 231 located on the second side are spaced very close together in the thickness direction of the guide rail. For example, the distance is less than or equal to 1 mm.

[0077] This configuration limits the width D5 of the light-shielding plate 231 to be greater than the staggered distances D2 and D4 of the guide grooves 211, and limits the spacing between the light-shielding plates 231 located on the two sides of the same guide rail in their thickness direction to be less than or equal to 1 mm. The former ensures that the light-shielding plates 231 extending from both sides of the guide rail have sufficient width to overlap during movement, thereby achieving continuous blocking coverage, avoiding gaps in light leakage, and forming a tight blockage. The latter controls the non-working gap between the two light-shielding plates 231 within a very small range, minimizing unnecessary light leakage caused by structural gaps. The combination of these two features ensures that the staggered light-shielding structure can achieve a high-precision, seamless, continuous area blocking effect.

[0078] In some embodiments, the maximum travel distance of the light-shielding plate 231 from its initial position toward the center of the light-transmitting hole 11 is L1, where L1 is greater than the aperture M of the light-transmitting hole 11. This allows the light-shielding plate 231 on one side to move independently to a position that completely blocks the light-transmitting hole 11. Simultaneously, when both light-shielding plates 231 are in their initial positions, the distance between the blade ends of the two light-shielding plates 231 is L2, which should also be greater than the aperture M of the light-transmitting hole 11, to ensure that the light beam can pass through completely unobstructed in the initial state. And / or, the radial distance between the first guide rail 21 and the second guide rail 22 in the light-transmitting hole 11 is L3, where L3 > M.

[0079] It should be noted that when the entire device is in accordance with Figure 3 When placed in the direction shown, the blade ends of the two light-shielding plates 231 refer to the distance between the two light-shielding plates 231 and the opposite light-shielding plate 231. In other words, the distance between the right end face of the light-shielding plate 231 on the left side and the left end face of the light-shielding plate 231 on the right side is L2.

[0080] The distance L3 in the left-right direction is between the right end face of the first guide rail 21 on the left side and the left end face of the second guide rail 22 on the right side.

[0081] Exemplarily, M < L1 < L2, which ensures that the single-sided light-shielding plate 231 can complete full occlusion independently, and the total distance that the light-shielding plates 231 on both sides move towards each other will not cause mechanical collision before they reach the full-occlusion position. In addition, the number N of the light-shielding plates 231 satisfies N ≥ 4M / D1. With this setting, it is ensured that within the diameter M range of the light-transmitting hole 11, at least a sufficient number of light-shielding plates 231 can be arranged radially. Since the light-shielding plates 231 are symmetric on both sides and the center-to-center distance of the light-shielding plates 231 is D1 / 2. Quantitatively, it ensures that the system has sufficient spatial sampling points and can achieve sufficiently fine discretization control of the diameter of the light-transmitting hole 11, which is the basis for the system to approximate the target occlusion pattern with high resolution. And when all N light-shielding plates are extended, they can completely occlude the light-transmitting area, avoiding or reducing the risk of light leakage.

[0082] With this setting, it is defined that the maximum stroke L1 of the light-shielding plate 231 is greater than the aperture M of the light-transmitting hole 11, ensuring that a single unilateral light-shielding plate 231 has sufficient moving range and can move from a position completely out of the optical path to a position sufficient to completely cover the light-transmitting hole 11, providing a stroke guarantee for achieving full-aperture occlusion. At the same time, it is defined that the initial interval distance L2 between the light-shielding plates 231 on both sides of the guide rails in the radial direction of the light-transmitting hole 11 is greater than L1, reserving sufficient space for the light-shielding plates 231 on both sides to move towards each other until they contact or overlap, preventing the light-shielding plates 231 from colliding or mechanically interfering during the movement due to insufficient stroke or too small initial spacing, and ensuring the feasibility and safety of the mechanism movement.

[0083] In some embodiments, the side of the light-shielding plate 231 facing the Fourier optical surface 300 is a plane.

[0084] With this setting, it is defined that the side of the light-shielding plate 231 facing the Fourier optical surface 300 is a plane. When the edge of the light-shielding plate 231 faces the complex light field on the Fourier optical surface 300, it can form a clear and sharp geometric boundary. Compared with a beveled or rounded edge, a planar edge can more effectively cut off light, reduce stray light generated by edge diffraction or scattering, avoid introducing new noise during the filtering process, thereby ensuring the effectiveness of the occlusion operation and further improving the signal-to-noise ratio of the final signal.

[0085] See Figure 6As shown, the detection unit 200 also includes a support frame 4 fixed inside the housing 1. The support frame 4 includes a frame located in the middle of the housing 1 and frame members located on both sides of the housing 1. The drive assembly 3 extends in the left-right direction and is arranged between the middle frame member and the two side frames. The drive assembly 3 includes a drive component for driving the first light-shielding component 23 and the second light-shielding component 24. Each drive component includes a driver 311, a drive rod 312 and a connecting rod 313.

[0086] With this configuration, a support frame 4 is added inside the housing 1, and the drive assembly 3 is specifically defined as a first drive component 31 and a second drive component 32 respectively mounted on it, which are connected to and drive the first light-shielding component 23 and the second light-shielding component 24 respectively. The support frame 4 provides a stable mounting base for the drive components, ensuring the stability of the drive force transmission. The independent drive components allow the light-shielding components on both sides to be controlled separately, thereby forming an asymmetrical shading pattern, enhancing the filtering capability for asymmetrical noise distribution, and improving the applicability and flexibility of the system.

[0087] The driver 311 is typically a geared motor with an incremental encoder, fixed to the support frame 4 by screws. The output shaft of the driver 311 is connected to the drive rod 312 via a coupling 314. The drive rod 312 can be a lead screw.

[0088] In this way, the actuator 311 provides rotational power, the drive rod 312 converts the rotational motion into linear motion, and finally pushes the light-shielding plate 231 through the connecting rod 313. In this way, the output of the actuator 311 is accurately and directly transmitted to the light-shielding plate 231, forming a simple, reliable, easy-to-control and compact linear drive structure.

[0089] Optionally, the drive rod 312 is connected to the support frame 4 by a bearing, and the bearing is supported by a bearing housing. Setting a bearing between the drive rod 312 and the support frame 4 can improve the smoothness and stability of the rotation of the drive rod 312.

[0090] For example, the adjustment precision of the drive component 3 is: , where P is the pitch of the drive rod 312, and θ is the shaft angle error of the geared motor.

[0091] Optionally, the coupling 314 in the drive assembly 3 is a flexible coupling 314. The coupling 314 allows for minor angular and radial deviations between the output shaft of the driver 311 and the drive rod 312, avoiding motion jamming problems caused by motor installation errors or lead screw deflection.

[0092] The connecting rod 313 is fitted onto the drive rod 312 through its internally machined thread. When the driver 311 rotates, it drives the drive rod 312 to rotate through the coupling 314. The thread inside the connecting rod 313 interacts with the rotating drive rod 312, thereby converting the rotational motion of the drive rod 312 into linear motion of the connecting rod 313 along the axis of the drive rod 312.

[0093] The end of the connecting rod 313 away from the drive rod 312 is connected to the light-shielding plate 231. In this way, the linear movement of the connecting rod 313 directly drives the light-shielding plate 231 to slide within the guide groove 211 of its guide rail.

[0094] The number of driving components is the same as the number of light-shielding plate groups, meaning that each light-shielding plate group corresponds to an independent driving component, achieving independent control.

[0095] In other words, the number of first driving components 31 is the same as the number of light-shielding plates 231 in the light-shielding plate group of the first light-shielding component 23. When there are multiple light-shielding groups in the first light-shielding component 31, the connecting rods 313 in the multiple first driving components 31 are arranged alternately in the thickness direction of the housing 1. The number of second driving components 32 is the same as the number of light-shielding plates 231 in the light-shielding plate group of the second light-shielding component 24. When there are multiple light-shielding groups in the second light-shielding component 24, the connecting rods 313 in the multiple second driving components 24 are arranged alternately in the thickness direction of the housing 1.

[0096] It should be noted that when there are multiple light-shielding plate groups in the first light-shielding component 23, there are also multiple connecting rods 313 in the first driving component 31. The number of connecting rods 313 in the first driving component 31 is the same as the number of light-shielding plates 231 in each light-shielding group. For example, when each light-shielding group in the first light-shielding component 31 has 3 light-shielding plates 231, then the first driving component 31 has 3 connecting rods 313, and the 3 connecting rods 313 are connected one-to-one with the 3 light-shielding plates 23. Furthermore, the lengths of the 3 connecting rods 313 are different, for example, in the thickness direction of the housing 1 (see...). Figure 1 (As shown in the front-back direction) The closer to the first guide rail 21, the shorter the length of the connecting rod 313; conversely, the farther away from the first guide rail 21, the longer the length of the connecting rod 313. The three connecting rods 313 of different lengths are arranged alternately in the thickness direction of the housing, thereby minimizing the space occupied by the connecting rods 313, reducing the size of the entire device, and making the structure more compact.

[0097] Similarly, when there are multiple light-shielding plate groups in the second light-shielding component 24, there are also multiple connecting rods 313 in the second driving component 24, and the number of connecting rods 313 in the second driving component 24 is the same as the number of light-shielding plates 231 in each light-shielding group.

[0098] This configuration, by arranging the connecting rods of multiple drive components corresponding to multiple light-shielding plate groups in a staggered manner along the thickness direction of the housing, alters the spatial layout of the drive components. Compared to the long radial space required for straight-line arrangement in related technologies, this disclosure utilizes the space in the thickness direction, achieving mutual avoidance through the staggered arrangement of connecting rods of different lengths. This allows multiple drive components and their transmission mechanisms to be compactly integrated within a limited radial dimension. By slightly increasing the dimension in the thickness direction, independent control of one drive per group is achieved. While ensuring that each light-shielding group can be driven independently and precisely, the space utilization of the system is optimized, resulting in an extremely compact overall structure. This solves the problem of excessively large radial dimensions in multi-drive unit layouts, providing key support for the miniaturization and integration of the system. In this way, each light-shielding plate group can be controlled by an independent drive component. This one-to-one drive configuration enables independent closed-loop control of each light-shielding plate group, allowing the system to generate complex shading patterns, such as different shading widths at different height positions. This increases the complexity and flexibility of the system's filtering shape, enabling it to cope with the most complex noise distribution conditions.

[0099] To ensure smooth linear movement of the connecting rod 313 and the light-shielding plate 231, the system also includes a guide assembly 5. The guide assembly 5 includes a guide rod 51 and a guide bearing 52 sleeved on the guide rod 51. For example, the guide bearing 52 can be a linear bearing. The linear bearing can slide freely and with low resistance on the guide rod 51.

[0100] It should be noted that the axial direction of the guide rod 51 is parallel to the axial direction of the drive rod 312. Furthermore, the linear bearing is connected to the connecting rod 313. Therefore, when the drive rod 312 drives the connecting rod 313, the connecting rod 313 simultaneously drives the linear bearing to slide along the guide rod 51. The guiding system formed by the guide rod 51 and the linear bearing ensures that the entire moving assembly moves strictly along a predetermined linear trajectory, withstands the radial force during movement, and avoids jamming or swaying.

[0101] This configuration adds a guide assembly 5 within the housing 1, staggered in the height direction from the drive assembly 3. The guide assembly 5 includes a guide rod 51 and a movable guide bearing 52 fitted onto it, with the guide bearing 52 connected to the connecting rod 313. The guide assembly 5 provides the connecting rod 313 with a second support point away from the drive end, forming a stable two-point support together with the drive end. This effectively resists the overturning moment or lateral displacement of the light-shielding plate 231 caused by uneven force during movement, ensuring that the light-shielding plate 231 always moves smoothly along the radial straight line specified by the guide groove 211, maintaining long-term movement accuracy.

[0102] See Figure 5As shown, the main extension directions of the drive assembly 3, guide assembly 5, and motion assembly are parallel to each other. Furthermore, the three are not simply arranged in a straight line in space, but rather arranged through spatial folding. Specifically, the drive rod 312 and guide rod 51 are typically staggered or arranged side-by-side in the height direction of the housing 1. The connecting rod 313 serves as a transition component; one end of the connecting rod 313 is connected to the light-shielding plate 231, while the other end is connected to both the drive rod 312 and the linear bearing. This allows the rotational power provided by the drive assembly 3 and the linear constraint provided by the guide assembly 5 to be transmitted and acted upon by the motion assembly through the same connecting rod 313. By spatially superimposing the three functional units of power transmission, motion guidance, and final execution, the lateral space occupied by the entire mechanism in the direction perpendicular to the beam axis and in the translational direction is reduced, making the cross-sectional profile of the entire detection unit 200 more compact and adaptable to the more confined installation environment of the optical system.

[0103] To ensure the safe operation of each independent motion unit and prevent mechanical collisions caused by excessive movement due to abnormal control, the detection unit 200 is also equipped with a limit component 6. The limit component 6 includes a sensor 62 and a limit switch 61.

[0104] For example, sensor 62 can be a sensing element, which is fixedly mounted on connecting rod 313, for example, near one end of guide bearing 52. Limit switch 61 is fixedly mounted on the side of support frame 4 adjacent to guide bearing 52; in other words, the sensing end of limit switch 61 is located on the movement path of sensor 62.

[0105] When the connecting rod 313 moves the light-shielding plate 231 to its limit position, the sensor 62 will enter the effective sensing distance of the limit switch 61. The limit switch 61 then generates an electrical signal, which is transmitted to the control system. Upon receiving the signal, the control system can immediately cut off the corresponding driver 311 or trigger the emergency stop logic, thereby achieving limit protection before the mechanical hard stop contacts.

[0106] This configuration adds a limit assembly 6, including a limit switch 61 and a sensor 62. The sensor 62 is mounted on the connecting rod 313 near the guide bearing 52, corresponding to the limit switch 61 on the housing 1. This provides mechanical limit position protection for the movement of the light-shielding plate 231. When the light-shielding plate 231 moves to its limit position, the sensor 62 triggers the limit switch 61, which can immediately cut off the drive or send a signal to prevent the light-shielding plate 231 from overtraveling due to control errors or malfunctions, thus preventing it from colliding with adjacent components or the housing 1, thereby protecting the mechanical structure from damage and improving the safety and reliability of the system.

[0107] The second aspect of this disclosure discloses a Fourier leaf filter detection system, comprising: The receiving optical module is used to receive the optical features after Fourier surface filtering; The monitoring optical module is used to monitor optical features on the Fourier transform surface; A detection device, wherein the detection device is the Fourier surface filter as described in any one of the first aspects.

[0108] This configuration, by integrating a receiving optical module, a monitoring optical module, and a precision adjustable filtering detection device as described in the first aspect, constructs a fully functional intelligent detection system with real-time feedback. The monitoring optical module can observe the light field distribution on the Fourier surface in real time, providing direct image or signal evidence for judging noise areas and evaluating filtering effects. The receiving optical module is specifically used to acquire the final optical signal after filtering by the detection device. These two modules work in conjunction with the programmable precision filtering detection device, enabling the system to dynamically and precisely control the light-shielding component 2 in the detection device based on feedback from the monitoring module, achieving optimal matching with the noise area. This not only inherits the advantages of the device in the first aspect, which allows for flexible and precise tuning of the filtering area, but also further achieves real-time optimization and self-adaptation of the filtering process through a closed loop of monitoring-adjustment-reception, thereby raising the signal-to-noise ratio and detection accuracy of the defect signal to a new level.

[0109] The Fourier surface filter detection device and detection system described in any of the above embodiments include the following steps in their corresponding filtering detection methods.

[0110] S100. Adjust the position of the housing 1 by means of the mounting bracket 100 so that the axis of the light-transmitting hole 11 on the housing 1 coincides with the optical axis of the light beam entering the housing 1.

[0111] It should be noted that this step is for system installation and rough alignment. The detection unit 200 is initially installed into the target optical path using the mounting bracket 100. The light source is turned on, allowing the beam to initially pass through the light-transmitting hole 11. Subsequently, the adjustment mechanism of the mounting bracket 100 is operated. It should be noted that the adjustment mechanism can be a slider and an adjusting nut on the mounting bracket 100. When the position of the detection unit 200 needs to be adjusted, the adjusting nut can be opened and the detection unit 200 moved. The angle of the detection unit 200 is adjusted by using the rotating shaft and the nut. For example, when adjusting the angle of the detection unit 200, the nut is opened and the rotating shaft is rotated to adjust the angle of the detection unit 200. After adjustment, the nut is tightened to achieve positioning.

[0112] S200: Determine whether the first central surface formed by the light shield 231 on the first side and the light shield 231 on the second side, and the second central surface formed by the light shield 231 on the third side and the light shield 231 on the fourth side coincide with the Fourier optical surface 300. If the three coincide, initialize the drive component 3 to initialize the position of the light shield component 2 inside the housing 1.

[0113] It should be noted that the adjustment process can begin by observing or using an alignment tool to ensure that the optical axis of the beam coincides with the geometric axis of the light-transmitting aperture 11, and that the beam passes through the light-transmitting aperture 11 uniformly and coaxially without any eccentric obstruction. Subsequently, through axial adjustment, the first center plane formed by the centers of the front and back light-blocking plates 231 in the first light-blocking component 23, and the second center plane formed by the centers of the front and back light-blocking plates 231 in the second light-blocking component 24, are both spatially aligned with the Fourier optical surface 300 calculated by the optical system. This ensures that the working reference plane of the filtering device is consistent with the theoretical optical plane.

[0114] After spatial alignment is completed, the detection unit 200 is initialized. All drivers 311 are controlled to perform zero-finding or reference-point return operations, so that each light-shielding plate 231 moves to a known, uniform initial position. The system records this initial position.

[0115] With this setup, the detection method first adjusts the position of the housing 1 using the mounting bracket 100 to ensure that the axis of the light-transmitting hole 11 coincides with the optical axis of the beam, establishing an accurate optical reference for the entire filtering process. Next, it initializes the process by determining whether the center plane of the light-shielding plate group coincides with the Fourier optical surface 300, establishing a repeatable mechanical zero position that is strictly aligned with the theoretical optical surface for the movement of all light-shielding plates 231. Finally, before controlling the movement of the light-shielding plates 231, a safety check is performed on their preset movement distance. This process combines precise mechanical adjustments with safe logical judgments, ensuring that each filtering operation is safely initiated under the premise of accurate reference and known position, thus guaranteeing the accuracy and repeatability of the filtering effect and the safety of the equipment itself from the operational process perspective.

[0116] S300: Determine whether the preset moving distance of each light-shielding plate 231 meets the preset conditions. If not, reset the preset moving distance of each light-shielding plate 231. If it meets the conditions, control each light-shielding plate 231 to move to the target position.

[0117] It should be noted that when filtering is required for a specific noise pattern, the operator or the host computer sets a target moving distance for each pair of light-shielding plates 231 that need to move. Before the drive motor moves, the control program will perform a logical judgment on the preset moving distance of each light-shielding plate 231 to prevent invalid or dangerous operation.

[0118] The preset condition can be to determine whether the preset movement distance of any one of the light-shielding plates 231 on one side exceeds its maximum allowable stroke L1. If it does, the setting is invalid and needs to be reset.

[0119] Alternatively, the preset condition can be that the light-shielding plates 231 move from both sides towards the center, and the sum of their preset movement distances exceeds the maximum allowable travel distance of their combination. If it does, the combined movement setting is invalid and needs to be readjusted.

[0120] Once all preset movement distances meet the preset conditions, the control system, according to the instructions, controls the corresponding driver 311 to rotate. The driver 311 drives the light-shielding plate 231 to move via the transmission screw and connecting rod 313. The encoder built into the driver 311 provides real-time feedback on the rotation angle of the motor, and through lead screw calculation, the actual displacement of the light-shielding plate 231 can be calculated with high precision. When the light-shielding plate 231 moves to the preset target position, the control system enables the driver 311 or maintains it at a small holding torque. At this time, the light-shielding plate 231 remains at the target position due to the self-locking characteristic of the transmission screw or the holding force of the motor, achieving continuous and stable blocking of a specific area of ​​the Fourier optical surface 300. The area in the beam corresponding to the noise distribution is effectively filtered out, while the defect signal is enhanced and transmitted, and is finally captured by the receiving optical module behind, thereby improving the contrast and detection accuracy of the defect image.

[0121] This configuration specifies the preset conditions as whether the preset movement distance of a single-sided light-shielding plate 231 exceeds its maximum stroke, and / or whether the sum of the preset movement distances of two paired light-shielding plates 231 exceeds the maximum stroke of their combination. This constitutes a dual safety verification logic. The former prevents a single light-shielding plate 231 from colliding with the mechanical limit switch due to incorrect instructions, while the latter prevents a pair of light-shielding plates 231 moving in opposite directions from colliding midway due to incorrect instructions. The software limit check performed before the movement is executed complements the hardware limit component 6, effectively preventing mechanical interference and damage caused by incorrect parameter settings or calculation errors, thus improving the safety and reliability of the system during automated operation.

[0122] The above description is merely a preferred embodiment of this disclosure and is not intended to limit this disclosure. Any modifications or equivalent substitutions made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.

Claims

1. A Fourier leaf filter detection device, characterized in that, include: A mounting frame and a detection unit, wherein the detection unit is mounted on the mounting frame and the mounting frame is used to adjust the three-dimensional spatial position of the detection unit; The detection unit includes a housing, a light-shielding component, and a driving component. The housing has a light-transmitting hole that passes through the housing, allowing a light beam to enter the housing to form a Fourier optical surface within the housing. The light-shielding component is disposed within the housing and is used to block the light-transmitting hole to adjust different light-shielding areas. The driving component is disposed within the housing and is used to drive the light-shielding component to move closer to or further away from the light-transmitting hole to adjust different light-shielding areas.

2. The Fourier leaf filter detection device according to claim 1, characterized in that, The light-shielding assembly includes a first guide rail, a second guide rail, a first light-shielding component, and a second light-shielding component. The first guide rail and the second guide rail are respectively disposed inside the housing and are symmetrically arranged on both sides of the light-transmitting hole. The first light-shielding component and the second light-shielding component are respectively connected to the first guide rail and the second light-shielding component. Both the first light-shielding component and the second light-shielding component include multiple light-shielding plates. The multiple light-shielding plates are arranged at intervals in the height direction of the housing, and the light-shielding plates in the first light-shielding component and the light-shielding plates in the second light-shielding component can move closer to each other and further away from each other.

3. The Fourier leaf filter detection device according to claim 2, characterized in that, The multiple light-shielding plates in the first and second light-shielding components are each divided into multiple groups of light-shielding plates. The multiple groups of light-shielding plates in the first light-shielding component are symmetrically arranged along the thickness direction of the first guide rail with the Fourier optical surface as the plane of symmetry. The multiple groups of light-shielding plates in the second light-shielding component are symmetrically arranged along the thickness direction of the second guide rail with the Fourier optical surface as the plane of symmetry. In the same direction, the light-shielding plate group of the first light-shielding component and the light-shielding plate group of the second light-shielding component are symmetrically distributed on both sides of the light-transmitting hole.

4. The Fourier leaf filter detection device according to claim 3, characterized in that, Each group of light-shielding plates has multiple light-shielding plates of the same quantity, and the multiple light-shielding plates are arranged at intervals in the height direction of the housing.

5. The Fourier leaf surface filter detection device according to claim 2, characterized in that, Both the first and second guide rails have multiple guide grooves that extend radially along the light-transmitting hole, and the multiple guide grooves are arranged at intervals along the height direction of the housing.

6. The Fourier leaf filter detection device according to claim 2, characterized in that, The first guide rail has a first side and a second side in its thickness direction. Multiple guide grooves are formed on both the first and second sides. These guide grooves are staggered in the height direction of the housing. The guide grooves on the first side are spaced apart by a distance D1, and the staggered distance between the guide grooves on the first and second sides is D2, where D1 = 2D2. The second guide rail has a third side and a fourth side in its thickness direction. Multiple guide grooves are formed on both the third side and the fourth side. The multiple guide grooves on the third side and the fourth side are staggered in the height direction of the housing. The multiple guide grooves on the third side are spaced apart by a distance D3, and the stagger distance between the guide grooves on the third side and the fourth side is D4. D3=2D4 and D3=D1.

7. The Fourier leaf filter detection device according to claim 6, characterized in that, The width of the light-shielding plate is D5, and D5 > D2 = D4. And / or, the distance between the light-shielding plate located on the first side and the light-shielding plate located on the second side in the thickness direction of the first guide rail is less than or equal to 1 mm. And / or, the distance between the light-shielding plate located on the third side and the light-shielding plate located on the fourth side in the thickness direction of the second guide rail is less than or equal to 1 mm.

8. The Fourier leaf surface filter detection device according to any one of claims 2 to 7, characterized in that, The side of the light-shielding plate facing the Fourier optical surface is a plane.

9. The Fourier leaf filter detection device according to any one of claims 2 to 7, characterized in that, The maximum travel distance of the light-shielding plate is L1, and L1 > M, where M is the aperture of the light-transmitting hole. And / or, the maximum radial distance between the light-shielding plate on the first guide rail and the light-shielding plate on the second guide rail in the light-transmitting hole is L2, and M < L1 < L2. And / or, the radial distance between the first guide rail and the second guide rail in the light-transmitting hole is L3, and L3 > M.

10. The Fourier leaf filter detection device according to any one of claims 2 to 7, characterized in that, The number of light-shielding plates is N, and N≥4M / D1.

11. The Fourier leaf surface filter detection device according to claim 3, characterized in that, It also includes a support frame disposed within the housing. The drive assembly includes a first drive component and a second drive component, which are respectively disposed on the support frame. The first drive component is connected to the first light-shielding component to drive the first light-shielding component to move closer to or away from the light-transmitting hole. The second drive component is connected to the second light-shielding component to drive the second light-shielding component to move closer to or away from the light-transmitting hole.

12. The Fourier leaf filter detection device according to claim 11, characterized in that, Both the first driving component and the second driving component include a driver, a driving rod, and a connecting rod. The driver is mounted on the support frame, and the output shaft of the driver is connected to the driving rod. The connecting rod is sleeved on the driving rod, and the driving rod can drive the connecting rod to move radially along the light-transmitting hole. The end of the connecting rod away from the driving rod is connected to the light-shielding plate.

13. The Fourier leaf filter detection device according to claim 12, characterized in that, The number of the first driving components is the same as the number of light-shielding plates in the light-shielding plate group of the first light-shielding component. When there are multiple light-shielding groups in the first light-shielding component, the connecting rods in the multiple first driving components are arranged alternately at intervals in the thickness direction of the housing. The number of the second driving components is the same as the number of light-shielding plates in the light-shielding plate group of the second light-shielding component. When there are multiple light-shielding groups in the second light-shielding component, the connecting rods in the multiple second driving components are arranged alternately at intervals in the thickness direction of the housing.

14. The Fourier leaf surface filter detection device according to claim 12, characterized in that, It also includes a guide assembly disposed within the housing, and the guide assembly and the drive assembly are arranged alternately in the height direction of the housing. The guiding assembly includes a guide rod and a guide bearing. The guide bearing is sleeved on the guide rod and is movable on the guide rod. The guide bearing is connected to the connecting rod.

15. The Fourier leaf filter detection device according to claim 14, characterized in that, It also includes a limiting assembly, which includes a limit switch and a sensor. The sensor is installed at one end of the connecting rod adjacent to the guide bearing, and the limit switch is located inside the housing and corresponds to the sensor.

16. A Fourier leaf filter detection system, characterized in that, include: The receiving optical module is used to receive the optical features after Fourier surface filtering; The monitoring optical module is used to monitor optical features on the Fourier transform surface; A detection device, wherein the detection device is a Fourier surface filter as described in any one of claims 1 to 15.

17. A Fourier leaf surface filtering detection method, characterized in that, Includes the following steps: Adjust the position of the housing using the mounting bracket so that the axis of the light-transmitting hole on the housing coincides with the optical axis of the light beam entering the housing; Determine whether the first central plane formed by the light shield on the first side and the light shield on the second side, and the second central plane formed by the light shield on the third side and the light shield on the fourth side, coincide with the Fourier optical plane. If they coincide, initialize the driving component to initialize the position of the light shield component within the housing. The system determines whether the preset moving distance of each light-shielding panel meets the preset conditions. If not, the preset moving distance of each light-shielding panel is reset. If it does, the system controls each light-shielding panel to move to the target position.

18. The Fourier leaf surface filtering detection method according to claim 17, characterized in that, The determination of whether the preset movement distance of each light-shielding plate meets the preset conditions includes: Determine whether the preset movement distance of the single-sided light-shielding plate exceeds its maximum travel, and / or, Determine whether the sum of the preset movement distances of the two paired light shields exceeds the maximum travel distance of the combination.

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